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 "reachable.h"
  28 #include "sha1-array.h"
  29 #include "argv-array.h"
  30 #include "list.h"
  31 #include "packfile.h"
  32 #include "object-store.h"
  33 #include "dir.h"
  34
  35 #define IN_PACK(obj) oe_in_pack(&to_pack, obj)
  36 #define SIZE(obj) oe_size(&to_pack, obj)
  37 #define SET_SIZE(obj,size) oe_set_size(&to_pack, obj, size)
  38 #define DELTA_SIZE(obj) oe_delta_size(&to_pack, obj)
  39 #define DELTA(obj) oe_delta(&to_pack, obj)
  40 #define DELTA_CHILD(obj) oe_delta_child(&to_pack, obj)
  41 #define DELTA_SIBLING(obj) oe_delta_sibling(&to_pack, obj)
  42 #define SET_DELTA(obj, val) oe_set_delta(&to_pack, obj, val)
  43 #define SET_DELTA_SIZE(obj, val) oe_set_delta_size(&to_pack, obj, val)
  44 #define SET_DELTA_CHILD(obj, val) oe_set_delta_child(&to_pack, obj, val)
  45 #define SET_DELTA_SIBLING(obj, val) oe_set_delta_sibling(&to_pack, obj, val)
  46
  47 static const char *pack_usage[] = {
  48         N_("git pack-objects --stdout [<options>...] [< <ref-list> | < <object-list>]"),
  49         N_("git pack-objects [<options>...] <base-name> [< <ref-list> | < <object-list>]"),
  50         NULL
  51 };
  52
  53 /*
  54  * Objects we are going to pack are collected in the `to_pack` structure.
  55  * It contains an array (dynamically expanded) of the object data, and a map
  56  * that can resolve SHA1s to their position in the array.
  57  */
  58 static struct packing_data to_pack;
  59
  60 static struct pack_idx_entry **written_list;
  61 static uint32_t nr_result, nr_written, nr_seen;
  62
  63 static int non_empty;
  64 static int reuse_delta = 1, reuse_object = 1;
  65 static int keep_unreachable, unpack_unreachable, include_tag;
  66 static timestamp_t unpack_unreachable_expiration;
  67 static int pack_loose_unreachable;
  68 static int local;
  69 static int have_non_local_packs;
  70 static int incremental;
  71 static int ignore_packed_keep_on_disk;
  72 static int ignore_packed_keep_in_core;
  73 static int allow_ofs_delta;
  74 static struct pack_idx_option pack_idx_opts;
  75 static const char *base_name;
  76 static int progress = 1;
  77 static int window = 10;
  78 static unsigned long pack_size_limit;
  79 static int depth = 50;
  80 static int delta_search_threads;
  81 static int pack_to_stdout;
  82 static int num_preferred_base;
  83 static struct progress *progress_state;
  84
  85 static struct packed_git *reuse_packfile;
  86 static uint32_t reuse_packfile_objects;
  87 static off_t reuse_packfile_offset;
  88
  89 static int use_bitmap_index_default = 1;
  90 static int use_bitmap_index = -1;
  91 static int write_bitmap_index;
  92 static uint16_t write_bitmap_options;
  93
  94 static int exclude_promisor_objects;
  95
  96 static unsigned long delta_cache_size = 0;
  97 static unsigned long max_delta_cache_size = DEFAULT_DELTA_CACHE_SIZE;
  98 static unsigned long cache_max_small_delta_size = 1000;
  99
 100 static unsigned long window_memory_limit = 0;
 101
 102 static struct list_objects_filter_options filter_options;
 103
 104 enum missing_action {
 105         MA_ERROR = 0,      /* fail if any missing objects are encountered */
 106         MA_ALLOW_ANY,      /* silently allow ALL missing objects */
 107         MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
 108 };
 109 static enum missing_action arg_missing_action;
 110 static show_object_fn fn_show_object;
 111
 112 /*
 113  * stats
 114  */
 115 static uint32_t written, written_delta;
 116 static uint32_t reused, reused_delta;
 117
 118 /*
 119  * Indexed commits
 120  */
 121 static struct commit **indexed_commits;
 122 static unsigned int indexed_commits_nr;
 123 static unsigned int indexed_commits_alloc;
 124
 125 static void index_commit_for_bitmap(struct commit *commit)
 126 {
 127         if (indexed_commits_nr >= indexed_commits_alloc) {
 128                 indexed_commits_alloc = (indexed_commits_alloc + 32) * 2;
 129                 REALLOC_ARRAY(indexed_commits, indexed_commits_alloc);
 130         }
 131
 132         indexed_commits[indexed_commits_nr++] = commit;
 133 }
 134
 135 static void *get_delta(struct object_entry *entry)
 136 {
 137         unsigned long size, base_size, delta_size;
 138         void *buf, *base_buf, *delta_buf;
 139         enum object_type type;
 140
 141         buf = read_object_file(&entry->idx.oid, &type, &size);
 142         if (!buf)
 143                 die(_("unable to read %s"), oid_to_hex(&entry->idx.oid));
 144         base_buf = read_object_file(&DELTA(entry)->idx.oid, &type,
 145                                     &base_size);
 146         if (!base_buf)
 147                 die("unable to read %s",
 148                     oid_to_hex(&DELTA(entry)->idx.oid));
 149         delta_buf = diff_delta(base_buf, base_size,
 150                                buf, size, &delta_size, 0);
 151         /*
 152          * We succesfully computed this delta once but dropped it for
 153          * memory reasons. Something is very wrong if this time we
 154          * recompute and create a different delta.
 155          */
 156         if (!delta_buf || delta_size != DELTA_SIZE(entry))
 157                 BUG("delta size changed");
 158         free(buf);
 159         free(base_buf);
 160         return delta_buf;
 161 }
 162
 163 static unsigned long do_compress(void **pptr, unsigned long size)
 164 {
 165         git_zstream stream;
 166         void *in, *out;
 167         unsigned long maxsize;
 168
 169         git_deflate_init(&stream, pack_compression_level);
 170         maxsize = git_deflate_bound(&stream, size);
 171
 172         in = *pptr;
 173         out = xmalloc(maxsize);
 174         *pptr = out;
 175
 176         stream.next_in = in;
 177         stream.avail_in = size;
 178         stream.next_out = out;
 179         stream.avail_out = maxsize;
 180         while (git_deflate(&stream, Z_FINISH) == Z_OK)
 181                 ; /* nothing */
 182         git_deflate_end(&stream);
 183
 184         free(in);
 185         return stream.total_out;
 186 }
 187
 188 static unsigned long write_large_blob_data(struct git_istream *st, struct hashfile *f,
 189                                            const struct object_id *oid)
 190 {
 191         git_zstream stream;
 192         unsigned char ibuf[1024 * 16];
 193         unsigned char obuf[1024 * 16];
 194         unsigned long olen = 0;
 195
 196         git_deflate_init(&stream, pack_compression_level);
 197
 198         for (;;) {
 199                 ssize_t readlen;
 200                 int zret = Z_OK;
 201                 readlen = read_istream(st, ibuf, sizeof(ibuf));
 202                 if (readlen == -1)
 203                         die(_("unable to read %s"), oid_to_hex(oid));
 204
 205                 stream.next_in = ibuf;
 206                 stream.avail_in = readlen;
 207                 while ((stream.avail_in || readlen == 0) &&
 208                        (zret == Z_OK || zret == Z_BUF_ERROR)) {
 209                         stream.next_out = obuf;
 210                         stream.avail_out = sizeof(obuf);
 211                         zret = git_deflate(&stream, readlen ? 0 : Z_FINISH);
 212                         hashwrite(f, obuf, stream.next_out - obuf);
 213                         olen += stream.next_out - obuf;
 214                 }
 215                 if (stream.avail_in)
 216                         die(_("deflate error (%d)"), zret);
 217                 if (readlen == 0) {
 218                         if (zret != Z_STREAM_END)
 219                                 die(_("deflate error (%d)"), zret);
 220                         break;
 221                 }
 222         }
 223         git_deflate_end(&stream);
 224         return olen;
 225 }
 226
 227 /*
 228  * we are going to reuse the existing object data as is.  make
 229  * sure it is not corrupt.
 230  */
 231 static int check_pack_inflate(struct packed_git *p,
 232                 struct pack_window **w_curs,
 233                 off_t offset,
 234                 off_t len,
 235                 unsigned long expect)
 236 {
 237         git_zstream stream;
 238         unsigned char fakebuf[4096], *in;
 239         int st;
 240
 241         memset(&stream, 0, sizeof(stream));
 242         git_inflate_init(&stream);
 243         do {
 244                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 245                 stream.next_in = in;
 246                 stream.next_out = fakebuf;
 247                 stream.avail_out = sizeof(fakebuf);
 248                 st = git_inflate(&stream, Z_FINISH);
 249                 offset += stream.next_in - in;
 250         } while (st == Z_OK || st == Z_BUF_ERROR);
 251         git_inflate_end(&stream);
 252         return (st == Z_STREAM_END &&
 253                 stream.total_out == expect &&
 254                 stream.total_in == len) ? 0 : -1;
 255 }
 256
 257 static void copy_pack_data(struct hashfile *f,
 258                 struct packed_git *p,
 259                 struct pack_window **w_curs,
 260                 off_t offset,
 261                 off_t len)
 262 {
 263         unsigned char *in;
 264         unsigned long avail;
 265
 266         while (len) {
 267                 in = use_pack(p, w_curs, offset, &avail);
 268                 if (avail > len)
 269                         avail = (unsigned long)len;
 270                 hashwrite(f, in, avail);
 271                 offset += avail;
 272                 len -= avail;
 273         }
 274 }
 275
 276 /* Return 0 if we will bust the pack-size limit */
 277 static unsigned long write_no_reuse_object(struct hashfile *f, struct object_entry *entry,
 278                                            unsigned long limit, int usable_delta)
 279 {
 280         unsigned long size, datalen;
 281         unsigned char header[MAX_PACK_OBJECT_HEADER],
 282                       dheader[MAX_PACK_OBJECT_HEADER];
 283         unsigned hdrlen;
 284         enum object_type type;
 285         void *buf;
 286         struct git_istream *st = NULL;
 287         const unsigned hashsz = the_hash_algo->rawsz;
 288
 289         if (!usable_delta) {
 290                 if (oe_type(entry) == OBJ_BLOB &&
 291                     oe_size_greater_than(&to_pack, entry, big_file_threshold) &&
 292                     (st = open_istream(&entry->idx.oid, &type, &size, NULL)) != NULL)
 293                         buf = NULL;
 294                 else {
 295                         buf = read_object_file(&entry->idx.oid, &type, &size);
 296                         if (!buf)
 297                                 die(_("unable to read %s"),
 298                                     oid_to_hex(&entry->idx.oid));
 299                 }
 300                 /*
 301                  * make sure no cached delta data remains from a
 302                  * previous attempt before a pack split occurred.
 303                  */
 304                 FREE_AND_NULL(entry->delta_data);
 305                 entry->z_delta_size = 0;
 306         } else if (entry->delta_data) {
 307                 size = DELTA_SIZE(entry);
 308                 buf = entry->delta_data;
 309                 entry->delta_data = NULL;
 310                 type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 311                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 312         } else {
 313                 buf = get_delta(entry);
 314                 size = DELTA_SIZE(entry);
 315                 type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 316                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 317         }
 318
 319         if (st) /* large blob case, just assume we don't compress well */
 320                 datalen = size;
 321         else if (entry->z_delta_size)
 322                 datalen = entry->z_delta_size;
 323         else
 324                 datalen = do_compress(&buf, size);
 325
 326         /*
 327          * The object header is a byte of 'type' followed by zero or
 328          * more bytes of length.
 329          */
 330         hdrlen = encode_in_pack_object_header(header, sizeof(header),
 331                                               type, size);
 332
 333         if (type == OBJ_OFS_DELTA) {
 334                 /*
 335                  * Deltas with relative base contain an additional
 336                  * encoding of the relative offset for the delta
 337                  * base from this object's position in the pack.
 338                  */
 339                 off_t ofs = entry->idx.offset - DELTA(entry)->idx.offset;
 340                 unsigned pos = sizeof(dheader) - 1;
 341                 dheader[pos] = ofs & 127;
 342                 while (ofs >>= 7)
 343                         dheader[--pos] = 128 | (--ofs & 127);
 344                 if (limit && hdrlen + sizeof(dheader) - pos + datalen + hashsz >= limit) {
 345                         if (st)
 346                                 close_istream(st);
 347                         free(buf);
 348                         return 0;
 349                 }
 350                 hashwrite(f, header, hdrlen);
 351                 hashwrite(f, dheader + pos, sizeof(dheader) - pos);
 352                 hdrlen += sizeof(dheader) - pos;
 353         } else if (type == OBJ_REF_DELTA) {
 354                 /*
 355                  * Deltas with a base reference contain
 356                  * additional bytes for the base object ID.
 357                  */
 358                 if (limit && hdrlen + hashsz + datalen + hashsz >= limit) {
 359                         if (st)
 360                                 close_istream(st);
 361                         free(buf);
 362                         return 0;
 363                 }
 364                 hashwrite(f, header, hdrlen);
 365                 hashwrite(f, DELTA(entry)->idx.oid.hash, hashsz);
 366                 hdrlen += hashsz;
 367         } else {
 368                 if (limit && hdrlen + datalen + hashsz >= limit) {
 369                         if (st)
 370                                 close_istream(st);
 371                         free(buf);
 372                         return 0;
 373                 }
 374                 hashwrite(f, header, hdrlen);
 375         }
 376         if (st) {
 377                 datalen = write_large_blob_data(st, f, &entry->idx.oid);
 378                 close_istream(st);
 379         } else {
 380                 hashwrite(f, buf, datalen);
 381                 free(buf);
 382         }
 383
 384         return hdrlen + datalen;
 385 }
 386
 387 /* Return 0 if we will bust the pack-size limit */
 388 static off_t write_reuse_object(struct hashfile *f, struct object_entry *entry,
 389                                 unsigned long limit, int usable_delta)
 390 {
 391         struct packed_git *p = IN_PACK(entry);
 392         struct pack_window *w_curs = NULL;
 393         struct revindex_entry *revidx;
 394         off_t offset;
 395         enum object_type type = oe_type(entry);
 396         off_t datalen;
 397         unsigned char header[MAX_PACK_OBJECT_HEADER],
 398                       dheader[MAX_PACK_OBJECT_HEADER];
 399         unsigned hdrlen;
 400         const unsigned hashsz = the_hash_algo->rawsz;
 401         unsigned long entry_size = SIZE(entry);
 402
 403         if (DELTA(entry))
 404                 type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 405                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 406         hdrlen = encode_in_pack_object_header(header, sizeof(header),
 407                                               type, entry_size);
 408
 409         offset = entry->in_pack_offset;
 410         revidx = find_pack_revindex(p, offset);
 411         datalen = revidx[1].offset - offset;
 412         if (!pack_to_stdout && p->index_version > 1 &&
 413             check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 414                 error(_("bad packed object CRC for %s"),
 415                       oid_to_hex(&entry->idx.oid));
 416                 unuse_pack(&w_curs);
 417                 return write_no_reuse_object(f, entry, limit, usable_delta);
 418         }
 419
 420         offset += entry->in_pack_header_size;
 421         datalen -= entry->in_pack_header_size;
 422
 423         if (!pack_to_stdout && p->index_version == 1 &&
 424             check_pack_inflate(p, &w_curs, offset, datalen, entry_size)) {
 425                 error(_("corrupt packed object for %s"),
 426                       oid_to_hex(&entry->idx.oid));
 427                 unuse_pack(&w_curs);
 428                 return write_no_reuse_object(f, entry, limit, usable_delta);
 429         }
 430
 431         if (type == OBJ_OFS_DELTA) {
 432                 off_t ofs = entry->idx.offset - DELTA(entry)->idx.offset;
 433                 unsigned pos = sizeof(dheader) - 1;
 434                 dheader[pos] = ofs & 127;
 435                 while (ofs >>= 7)
 436                         dheader[--pos] = 128 | (--ofs & 127);
 437                 if (limit && hdrlen + sizeof(dheader) - pos + datalen + hashsz >= limit) {
 438                         unuse_pack(&w_curs);
 439                         return 0;
 440                 }
 441                 hashwrite(f, header, hdrlen);
 442                 hashwrite(f, dheader + pos, sizeof(dheader) - pos);
 443                 hdrlen += sizeof(dheader) - pos;
 444                 reused_delta++;
 445         } else if (type == OBJ_REF_DELTA) {
 446                 if (limit && hdrlen + hashsz + datalen + hashsz >= limit) {
 447                         unuse_pack(&w_curs);
 448                         return 0;
 449                 }
 450                 hashwrite(f, header, hdrlen);
 451                 hashwrite(f, DELTA(entry)->idx.oid.hash, hashsz);
 452                 hdrlen += hashsz;
 453                 reused_delta++;
 454         } else {
 455                 if (limit && hdrlen + datalen + hashsz >= limit) {
 456                         unuse_pack(&w_curs);
 457                         return 0;
 458                 }
 459                 hashwrite(f, header, hdrlen);
 460         }
 461         copy_pack_data(f, p, &w_curs, offset, datalen);
 462         unuse_pack(&w_curs);
 463         reused++;
 464         return hdrlen + datalen;
 465 }
 466
 467 /* Return 0 if we will bust the pack-size limit */
 468 static off_t write_object(struct hashfile *f,
 469                           struct object_entry *entry,
 470                           off_t write_offset)
 471 {
 472         unsigned long limit;
 473         off_t len;
 474         int usable_delta, to_reuse;
 475
 476         if (!pack_to_stdout)
 477                 crc32_begin(f);
 478
 479         /* apply size limit if limited packsize and not first object */
 480         if (!pack_size_limit || !nr_written)
 481                 limit = 0;
 482         else if (pack_size_limit <= write_offset)
 483                 /*
 484                  * the earlier object did not fit the limit; avoid
 485                  * mistaking this with unlimited (i.e. limit = 0).
 486                  */
 487                 limit = 1;
 488         else
 489                 limit = pack_size_limit - write_offset;
 490
 491         if (!DELTA(entry))
 492                 usable_delta = 0;       /* no delta */
 493         else if (!pack_size_limit)
 494                usable_delta = 1;        /* unlimited packfile */
 495         else if (DELTA(entry)->idx.offset == (off_t)-1)
 496                 usable_delta = 0;       /* base was written to another pack */
 497         else if (DELTA(entry)->idx.offset)
 498                 usable_delta = 1;       /* base already exists in this pack */
 499         else
 500                 usable_delta = 0;       /* base could end up in another pack */
 501
 502         if (!reuse_object)
 503                 to_reuse = 0;   /* explicit */
 504         else if (!IN_PACK(entry))
 505                 to_reuse = 0;   /* can't reuse what we don't have */
 506         else if (oe_type(entry) == OBJ_REF_DELTA ||
 507                  oe_type(entry) == OBJ_OFS_DELTA)
 508                                 /* check_object() decided it for us ... */
 509                 to_reuse = usable_delta;
 510                                 /* ... but pack split may override that */
 511         else if (oe_type(entry) != entry->in_pack_type)
 512                 to_reuse = 0;   /* pack has delta which is unusable */
 513         else if (DELTA(entry))
 514                 to_reuse = 0;   /* we want to pack afresh */
 515         else
 516                 to_reuse = 1;   /* we have it in-pack undeltified,
 517                                  * and we do not need to deltify it.
 518                                  */
 519
 520         if (!to_reuse)
 521                 len = write_no_reuse_object(f, entry, limit, usable_delta);
 522         else
 523                 len = write_reuse_object(f, entry, limit, usable_delta);
 524         if (!len)
 525                 return 0;
 526
 527         if (usable_delta)
 528                 written_delta++;
 529         written++;
 530         if (!pack_to_stdout)
 531                 entry->idx.crc32 = crc32_end(f);
 532         return len;
 533 }
 534
 535 enum write_one_status {
 536         WRITE_ONE_SKIP = -1, /* already written */
 537         WRITE_ONE_BREAK = 0, /* writing this will bust the limit; not written */
 538         WRITE_ONE_WRITTEN = 1, /* normal */
 539         WRITE_ONE_RECURSIVE = 2 /* already scheduled to be written */
 540 };
 541
 542 static enum write_one_status write_one(struct hashfile *f,
 543                                        struct object_entry *e,
 544                                        off_t *offset)
 545 {
 546         off_t size;
 547         int recursing;
 548
 549         /*
 550          * we set offset to 1 (which is an impossible value) to mark
 551          * the fact that this object is involved in "write its base
 552          * first before writing a deltified object" recursion.
 553          */
 554         recursing = (e->idx.offset == 1);
 555         if (recursing) {
 556                 warning(_("recursive delta detected for object %s"),
 557                         oid_to_hex(&e->idx.oid));
 558                 return WRITE_ONE_RECURSIVE;
 559         } else if (e->idx.offset || e->preferred_base) {
 560                 /* offset is non zero if object is written already. */
 561                 return WRITE_ONE_SKIP;
 562         }
 563
 564         /* if we are deltified, write out base object first. */
 565         if (DELTA(e)) {
 566                 e->idx.offset = 1; /* now recurse */
 567                 switch (write_one(f, DELTA(e), offset)) {
 568                 case WRITE_ONE_RECURSIVE:
 569                         /* we cannot depend on this one */
 570                         SET_DELTA(e, NULL);
 571                         break;
 572                 default:
 573                         break;
 574                 case WRITE_ONE_BREAK:
 575                         e->idx.offset = recursing;
 576                         return WRITE_ONE_BREAK;
 577                 }
 578         }
 579
 580         e->idx.offset = *offset;
 581         size = write_object(f, e, *offset);
 582         if (!size) {
 583                 e->idx.offset = recursing;
 584                 return WRITE_ONE_BREAK;
 585         }
 586         written_list[nr_written++] = &e->idx;
 587
 588         /* make sure off_t is sufficiently large not to wrap */
 589         if (signed_add_overflows(*offset, size))
 590                 die(_("pack too large for current definition of off_t"));
 591         *offset += size;
 592         return WRITE_ONE_WRITTEN;
 593 }
 594
 595 static int mark_tagged(const char *path, const struct object_id *oid, int flag,
 596                        void *cb_data)
 597 {
 598         struct object_id peeled;
 599         struct object_entry *entry = packlist_find(&to_pack, oid->hash, NULL);
 600
 601         if (entry)
 602                 entry->tagged = 1;
 603         if (!peel_ref(path, &peeled)) {
 604                 entry = packlist_find(&to_pack, peeled.hash, NULL);
 605                 if (entry)
 606                         entry->tagged = 1;
 607         }
 608         return 0;
 609 }
 610
 611 static inline void add_to_write_order(struct object_entry **wo,
 612                                unsigned int *endp,
 613                                struct object_entry *e)
 614 {
 615         if (e->filled)
 616                 return;
 617         wo[(*endp)++] = e;
 618         e->filled = 1;
 619 }
 620
 621 static void add_descendants_to_write_order(struct object_entry **wo,
 622                                            unsigned int *endp,
 623                                            struct object_entry *e)
 624 {
 625         int add_to_order = 1;
 626         while (e) {
 627                 if (add_to_order) {
 628                         struct object_entry *s;
 629                         /* add this node... */
 630                         add_to_write_order(wo, endp, e);
 631                         /* all its siblings... */
 632                         for (s = DELTA_SIBLING(e); s; s = DELTA_SIBLING(s)) {
 633                                 add_to_write_order(wo, endp, s);
 634                         }
 635                 }
 636                 /* drop down a level to add left subtree nodes if possible */
 637                 if (DELTA_CHILD(e)) {
 638                         add_to_order = 1;
 639                         e = DELTA_CHILD(e);
 640                 } else {
 641                         add_to_order = 0;
 642                         /* our sibling might have some children, it is next */
 643                         if (DELTA_SIBLING(e)) {
 644                                 e = DELTA_SIBLING(e);
 645                                 continue;
 646                         }
 647                         /* go back to our parent node */
 648                         e = DELTA(e);
 649                         while (e && !DELTA_SIBLING(e)) {
 650                                 /* we're on the right side of a subtree, keep
 651                                  * going up until we can go right again */
 652                                 e = DELTA(e);
 653                         }
 654                         if (!e) {
 655                                 /* done- we hit our original root node */
 656                                 return;
 657                         }
 658                         /* pass it off to sibling at this level */
 659                         e = DELTA_SIBLING(e);
 660                 }
 661         };
 662 }
 663
 664 static void add_family_to_write_order(struct object_entry **wo,
 665                                       unsigned int *endp,
 666                                       struct object_entry *e)
 667 {
 668         struct object_entry *root;
 669
 670         for (root = e; DELTA(root); root = DELTA(root))
 671                 ; /* nothing */
 672         add_descendants_to_write_order(wo, endp, root);
 673 }
 674
 675 static struct object_entry **compute_write_order(void)
 676 {
 677         unsigned int i, wo_end, last_untagged;
 678
 679         struct object_entry **wo;
 680         struct object_entry *objects = to_pack.objects;
 681
 682         for (i = 0; i < to_pack.nr_objects; i++) {
 683                 objects[i].tagged = 0;
 684                 objects[i].filled = 0;
 685                 SET_DELTA_CHILD(&objects[i], NULL);
 686                 SET_DELTA_SIBLING(&objects[i], NULL);
 687         }
 688
 689         /*
 690          * Fully connect delta_child/delta_sibling network.
 691          * Make sure delta_sibling is sorted in the original
 692          * recency order.
 693          */
 694         for (i = to_pack.nr_objects; i > 0;) {
 695                 struct object_entry *e = &objects[--i];
 696                 if (!DELTA(e))
 697                         continue;
 698                 /* Mark me as the first child */
 699                 e->delta_sibling_idx = DELTA(e)->delta_child_idx;
 700                 SET_DELTA_CHILD(DELTA(e), e);
 701         }
 702
 703         /*
 704          * Mark objects that are at the tip of tags.
 705          */
 706         for_each_tag_ref(mark_tagged, NULL);
 707
 708         /*
 709          * Give the objects in the original recency order until
 710          * we see a tagged tip.
 711          */
 712         ALLOC_ARRAY(wo, to_pack.nr_objects);
 713         for (i = wo_end = 0; i < to_pack.nr_objects; i++) {
 714                 if (objects[i].tagged)
 715                         break;
 716                 add_to_write_order(wo, &wo_end, &objects[i]);
 717         }
 718         last_untagged = i;
 719
 720         /*
 721          * Then fill all the tagged tips.
 722          */
 723         for (; i < to_pack.nr_objects; i++) {
 724                 if (objects[i].tagged)
 725                         add_to_write_order(wo, &wo_end, &objects[i]);
 726         }
 727
 728         /*
 729          * And then all remaining commits and tags.
 730          */
 731         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 732                 if (oe_type(&objects[i]) != OBJ_COMMIT &&
 733                     oe_type(&objects[i]) != OBJ_TAG)
 734                         continue;
 735                 add_to_write_order(wo, &wo_end, &objects[i]);
 736         }
 737
 738         /*
 739          * And then all the trees.
 740          */
 741         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 742                 if (oe_type(&objects[i]) != OBJ_TREE)
 743                         continue;
 744                 add_to_write_order(wo, &wo_end, &objects[i]);
 745         }
 746
 747         /*
 748          * Finally all the rest in really tight order
 749          */
 750         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 751                 if (!objects[i].filled)
 752                         add_family_to_write_order(wo, &wo_end, &objects[i]);
 753         }
 754
 755         if (wo_end != to_pack.nr_objects)
 756                 die(_("ordered %u objects, expected %"PRIu32),
 757                     wo_end, to_pack.nr_objects);
 758
 759         return wo;
 760 }
 761
 762 static off_t write_reused_pack(struct hashfile *f)
 763 {
 764         unsigned char buffer[8192];
 765         off_t to_write, total;
 766         int fd;
 767
 768         if (!is_pack_valid(reuse_packfile))
 769                 die(_("packfile is invalid: %s"), reuse_packfile->pack_name);
 770
 771         fd = git_open(reuse_packfile->pack_name);
 772         if (fd < 0)
 773                 die_errno(_("unable to open packfile for reuse: %s"),
 774                           reuse_packfile->pack_name);
 775
 776         if (lseek(fd, sizeof(struct pack_header), SEEK_SET) == -1)
 777                 die_errno(_("unable to seek in reused packfile"));
 778
 779         if (reuse_packfile_offset < 0)
 780                 reuse_packfile_offset = reuse_packfile->pack_size - the_hash_algo->rawsz;
 781
 782         total = to_write = reuse_packfile_offset - sizeof(struct pack_header);
 783
 784         while (to_write) {
 785                 int read_pack = xread(fd, buffer, sizeof(buffer));
 786
 787                 if (read_pack <= 0)
 788                         die_errno(_("unable to read from reused packfile"));
 789
 790                 if (read_pack > to_write)
 791                         read_pack = to_write;
 792
 793                 hashwrite(f, buffer, read_pack);
 794                 to_write -= read_pack;
 795
 796                 /*
 797                  * We don't know the actual number of objects written,
 798                  * only how many bytes written, how many bytes total, and
 799                  * how many objects total. So we can fake it by pretending all
 800                  * objects we are writing are the same size. This gives us a
 801                  * smooth progress meter, and at the end it matches the true
 802                  * answer.
 803                  */
 804                 written = reuse_packfile_objects *
 805                                 (((double)(total - to_write)) / total);
 806                 display_progress(progress_state, written);
 807         }
 808
 809         close(fd);
 810         written = reuse_packfile_objects;
 811         display_progress(progress_state, written);
 812         return reuse_packfile_offset - sizeof(struct pack_header);
 813 }
 814
 815 static const char no_split_warning[] = N_(
 816 "disabling bitmap writing, packs are split due to pack.packSizeLimit"
 817 );
 818
 819 static void write_pack_file(void)
 820 {
 821         uint32_t i = 0, j;
 822         struct hashfile *f;
 823         off_t offset;
 824         uint32_t nr_remaining = nr_result;
 825         time_t last_mtime = 0;
 826         struct object_entry **write_order;
 827
 828         if (progress > pack_to_stdout)
 829                 progress_state = start_progress(_("Writing objects"), nr_result);
 830         ALLOC_ARRAY(written_list, to_pack.nr_objects);
 831         write_order = compute_write_order();
 832
 833         do {
 834                 struct object_id oid;
 835                 char *pack_tmp_name = NULL;
 836
 837                 if (pack_to_stdout)
 838                         f = hashfd_throughput(1, "<stdout>", progress_state);
 839                 else
 840                         f = create_tmp_packfile(&pack_tmp_name);
 841
 842                 offset = write_pack_header(f, nr_remaining);
 843
 844                 if (reuse_packfile) {
 845                         off_t packfile_size;
 846                         assert(pack_to_stdout);
 847
 848                         packfile_size = write_reused_pack(f);
 849                         offset += packfile_size;
 850                 }
 851
 852                 nr_written = 0;
 853                 for (; i < to_pack.nr_objects; i++) {
 854                         struct object_entry *e = write_order[i];
 855                         if (write_one(f, e, &offset) == WRITE_ONE_BREAK)
 856                                 break;
 857                         display_progress(progress_state, written);
 858                 }
 859
 860                 /*
 861                  * Did we write the wrong # entries in the header?
 862                  * If so, rewrite it like in fast-import
 863                  */
 864                 if (pack_to_stdout) {
 865                         finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_CLOSE);
 866                 } else if (nr_written == nr_remaining) {
 867                         finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
 868                 } else {
 869                         int fd = finalize_hashfile(f, oid.hash, 0);
 870                         fixup_pack_header_footer(fd, oid.hash, pack_tmp_name,
 871                                                  nr_written, oid.hash, offset);
 872                         close(fd);
 873                         if (write_bitmap_index) {
 874                                 warning(_(no_split_warning));
 875                                 write_bitmap_index = 0;
 876                         }
 877                 }
 878
 879                 if (!pack_to_stdout) {
 880                         struct stat st;
 881                         struct strbuf tmpname = STRBUF_INIT;
 882
 883                         /*
 884                          * Packs are runtime accessed in their mtime
 885                          * order since newer packs are more likely to contain
 886                          * younger objects.  So if we are creating multiple
 887                          * packs then we should modify the mtime of later ones
 888                          * to preserve this property.
 889                          */
 890                         if (stat(pack_tmp_name, &st) < 0) {
 891                                 warning_errno(_("failed to stat %s"), pack_tmp_name);
 892                         } else if (!last_mtime) {
 893                                 last_mtime = st.st_mtime;
 894                         } else {
 895                                 struct utimbuf utb;
 896                                 utb.actime = st.st_atime;
 897                                 utb.modtime = --last_mtime;
 898                                 if (utime(pack_tmp_name, &utb) < 0)
 899                                         warning_errno(_("failed utime() on %s"), pack_tmp_name);
 900                         }
 901
 902                         strbuf_addf(&tmpname, "%s-", base_name);
 903
 904                         if (write_bitmap_index) {
 905                                 bitmap_writer_set_checksum(oid.hash);
 906                                 bitmap_writer_build_type_index(
 907                                         &to_pack, written_list, nr_written);
 908                         }
 909
 910                         finish_tmp_packfile(&tmpname, pack_tmp_name,
 911                                             written_list, nr_written,
 912                                             &pack_idx_opts, oid.hash);
 913
 914                         if (write_bitmap_index) {
 915                                 strbuf_addf(&tmpname, "%s.bitmap", oid_to_hex(&oid));
 916
 917                                 stop_progress(&progress_state);
 918
 919                                 bitmap_writer_show_progress(progress);
 920                                 bitmap_writer_reuse_bitmaps(&to_pack);
 921                                 bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
 922                                 bitmap_writer_build(&to_pack);
 923                                 bitmap_writer_finish(written_list, nr_written,
 924                                                      tmpname.buf, write_bitmap_options);
 925                                 write_bitmap_index = 0;
 926                         }
 927
 928                         strbuf_release(&tmpname);
 929                         free(pack_tmp_name);
 930                         puts(oid_to_hex(&oid));
 931                 }
 932
 933                 /* mark written objects as written to previous pack */
 934                 for (j = 0; j < nr_written; j++) {
 935                         written_list[j]->offset = (off_t)-1;
 936                 }
 937                 nr_remaining -= nr_written;
 938         } while (nr_remaining && i < to_pack.nr_objects);
 939
 940         free(written_list);
 941         free(write_order);
 942         stop_progress(&progress_state);
 943         if (written != nr_result)
 944                 die(_("wrote %"PRIu32" objects while expecting %"PRIu32),
 945                     written, nr_result);
 946 }
 947
 948 static int no_try_delta(const char *path)
 949 {
 950         static struct attr_check *check;
 951
 952         if (!check)
 953                 check = attr_check_initl("delta", NULL);
 954         if (git_check_attr(&the_index, path, check))
 955                 return 0;
 956         if (ATTR_FALSE(check->items[0].value))
 957                 return 1;
 958         return 0;
 959 }
 960
 961 /*
 962  * When adding an object, check whether we have already added it
 963  * to our packing list. If so, we can skip. However, if we are
 964  * being asked to excludei t, but the previous mention was to include
 965  * it, make sure to adjust its flags and tweak our numbers accordingly.
 966  *
 967  * As an optimization, we pass out the index position where we would have
 968  * found the item, since that saves us from having to look it up again a
 969  * few lines later when we want to add the new entry.
 970  */
 971 static int have_duplicate_entry(const struct object_id *oid,
 972                                 int exclude,
 973                                 uint32_t *index_pos)
 974 {
 975         struct object_entry *entry;
 976
 977         entry = packlist_find(&to_pack, oid->hash, index_pos);
 978         if (!entry)
 979                 return 0;
 980
 981         if (exclude) {
 982                 if (!entry->preferred_base)
 983                         nr_result--;
 984                 entry->preferred_base = 1;
 985         }
 986
 987         return 1;
 988 }
 989
 990 static int want_found_object(int exclude, struct packed_git *p)
 991 {
 992         if (exclude)
 993                 return 1;
 994         if (incremental)
 995                 return 0;
 996
 997         /*
 998          * When asked to do --local (do not include an object that appears in a
 999          * pack we borrow from elsewhere) or --honor-pack-keep (do not include
1000          * an object that appears in a pack marked with .keep), finding a pack
1001          * that matches the criteria is sufficient for us to decide to omit it.
1002          * However, even if this pack does not satisfy the criteria, we need to
1003          * make sure no copy of this object appears in _any_ pack that makes us
1004          * to omit the object, so we need to check all the packs.
1005          *
1006          * We can however first check whether these options can possible matter;
1007          * if they do not matter we know we want the object in generated pack.
1008          * Otherwise, we signal "-1" at the end to tell the caller that we do
1009          * not know either way, and it needs to check more packs.
1010          */
1011         if (!ignore_packed_keep_on_disk &&
1012             !ignore_packed_keep_in_core &&
1013             (!local || !have_non_local_packs))
1014                 return 1;
1015
1016         if (local && !p->pack_local)
1017                 return 0;
1018         if (p->pack_local &&
1019             ((ignore_packed_keep_on_disk && p->pack_keep) ||
1020              (ignore_packed_keep_in_core && p->pack_keep_in_core)))
1021                 return 0;
1022
1023         /* we don't know yet; keep looking for more packs */
1024         return -1;
1025 }
1026
1027 /*
1028  * Check whether we want the object in the pack (e.g., we do not want
1029  * objects found in non-local stores if the "--local" option was used).
1030  *
1031  * If the caller already knows an existing pack it wants to take the object
1032  * from, that is passed in *found_pack and *found_offset; otherwise this
1033  * function finds if there is any pack that has the object and returns the pack
1034  * and its offset in these variables.
1035  */
1036 static int want_object_in_pack(const struct object_id *oid,
1037                                int exclude,
1038                                struct packed_git **found_pack,
1039                                off_t *found_offset)
1040 {
1041         int want;
1042         struct list_head *pos;
1043
1044         if (!exclude && local && has_loose_object_nonlocal(oid))
1045                 return 0;
1046
1047         /*
1048          * If we already know the pack object lives in, start checks from that
1049          * pack - in the usual case when neither --local was given nor .keep files
1050          * are present we will determine the answer right now.
1051          */
1052         if (*found_pack) {
1053                 want = want_found_object(exclude, *found_pack);
1054                 if (want != -1)
1055                         return want;
1056         }
1057         list_for_each(pos, get_packed_git_mru(the_repository)) {
1058                 struct packed_git *p = list_entry(pos, struct packed_git, mru);
1059                 off_t offset;
1060
1061                 if (p == *found_pack)
1062                         offset = *found_offset;
1063                 else
1064                         offset = find_pack_entry_one(oid->hash, p);
1065
1066                 if (offset) {
1067                         if (!*found_pack) {
1068                                 if (!is_pack_valid(p))
1069                                         continue;
1070                                 *found_offset = offset;
1071                                 *found_pack = p;
1072                         }
1073                         want = want_found_object(exclude, p);
1074                         if (!exclude && want > 0)
1075                                 list_move(&p->mru,
1076                                           get_packed_git_mru(the_repository));
1077                         if (want != -1)
1078                                 return want;
1079                 }
1080         }
1081
1082         return 1;
1083 }
1084
1085 static void create_object_entry(const struct object_id *oid,
1086                                 enum object_type type,
1087                                 uint32_t hash,
1088                                 int exclude,
1089                                 int no_try_delta,
1090                                 uint32_t index_pos,
1091                                 struct packed_git *found_pack,
1092                                 off_t found_offset)
1093 {
1094         struct object_entry *entry;
1095
1096         entry = packlist_alloc(&to_pack, oid->hash, index_pos);
1097         entry->hash = hash;
1098         oe_set_type(entry, type);
1099         if (exclude)
1100                 entry->preferred_base = 1;
1101         else
1102                 nr_result++;
1103         if (found_pack) {
1104                 oe_set_in_pack(&to_pack, entry, found_pack);
1105                 entry->in_pack_offset = found_offset;
1106         }
1107
1108         entry->no_try_delta = no_try_delta;
1109 }
1110
1111 static const char no_closure_warning[] = N_(
1112 "disabling bitmap writing, as some objects are not being packed"
1113 );
1114
1115 static int add_object_entry(const struct object_id *oid, enum object_type type,
1116                             const char *name, int exclude)
1117 {
1118         struct packed_git *found_pack = NULL;
1119         off_t found_offset = 0;
1120         uint32_t index_pos;
1121
1122         display_progress(progress_state, ++nr_seen);
1123
1124         if (have_duplicate_entry(oid, exclude, &index_pos))
1125                 return 0;
1126
1127         if (!want_object_in_pack(oid, exclude, &found_pack, &found_offset)) {
1128                 /* The pack is missing an object, so it will not have closure */
1129                 if (write_bitmap_index) {
1130                         warning(_(no_closure_warning));
1131                         write_bitmap_index = 0;
1132                 }
1133                 return 0;
1134         }
1135
1136         create_object_entry(oid, type, pack_name_hash(name),
1137                             exclude, name && no_try_delta(name),
1138                             index_pos, found_pack, found_offset);
1139         return 1;
1140 }
1141
1142 static int add_object_entry_from_bitmap(const struct object_id *oid,
1143                                         enum object_type type,
1144                                         int flags, uint32_t name_hash,
1145                                         struct packed_git *pack, off_t offset)
1146 {
1147         uint32_t index_pos;
1148
1149         display_progress(progress_state, ++nr_seen);
1150
1151         if (have_duplicate_entry(oid, 0, &index_pos))
1152                 return 0;
1153
1154         if (!want_object_in_pack(oid, 0, &pack, &offset))
1155                 return 0;
1156
1157         create_object_entry(oid, type, name_hash, 0, 0, index_pos, pack, offset);
1158         return 1;
1159 }
1160
1161 struct pbase_tree_cache {
1162         struct object_id oid;
1163         int ref;
1164         int temporary;
1165         void *tree_data;
1166         unsigned long tree_size;
1167 };
1168
1169 static struct pbase_tree_cache *(pbase_tree_cache[256]);
1170 static int pbase_tree_cache_ix(const struct object_id *oid)
1171 {
1172         return oid->hash[0] % ARRAY_SIZE(pbase_tree_cache);
1173 }
1174 static int pbase_tree_cache_ix_incr(int ix)
1175 {
1176         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
1177 }
1178
1179 static struct pbase_tree {
1180         struct pbase_tree *next;
1181         /* This is a phony "cache" entry; we are not
1182          * going to evict it or find it through _get()
1183          * mechanism -- this is for the toplevel node that
1184          * would almost always change with any commit.
1185          */
1186         struct pbase_tree_cache pcache;
1187 } *pbase_tree;
1188
1189 static struct pbase_tree_cache *pbase_tree_get(const struct object_id *oid)
1190 {
1191         struct pbase_tree_cache *ent, *nent;
1192         void *data;
1193         unsigned long size;
1194         enum object_type type;
1195         int neigh;
1196         int my_ix = pbase_tree_cache_ix(oid);
1197         int available_ix = -1;
1198
1199         /* pbase-tree-cache acts as a limited hashtable.
1200          * your object will be found at your index or within a few
1201          * slots after that slot if it is cached.
1202          */
1203         for (neigh = 0; neigh < 8; neigh++) {
1204                 ent = pbase_tree_cache[my_ix];
1205                 if (ent && !oidcmp(&ent->oid, oid)) {
1206                         ent->ref++;
1207                         return ent;
1208                 }
1209                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
1210                          ((0 <= available_ix) &&
1211                           (!ent && pbase_tree_cache[available_ix])))
1212                         available_ix = my_ix;
1213                 if (!ent)
1214                         break;
1215                 my_ix = pbase_tree_cache_ix_incr(my_ix);
1216         }
1217
1218         /* Did not find one.  Either we got a bogus request or
1219          * we need to read and perhaps cache.
1220          */
1221         data = read_object_file(oid, &type, &size);
1222         if (!data)
1223                 return NULL;
1224         if (type != OBJ_TREE) {
1225                 free(data);
1226                 return NULL;
1227         }
1228
1229         /* We need to either cache or return a throwaway copy */
1230
1231         if (available_ix < 0)
1232                 ent = NULL;
1233         else {
1234                 ent = pbase_tree_cache[available_ix];
1235                 my_ix = available_ix;
1236         }
1237
1238         if (!ent) {
1239                 nent = xmalloc(sizeof(*nent));
1240                 nent->temporary = (available_ix < 0);
1241         }
1242         else {
1243                 /* evict and reuse */
1244                 free(ent->tree_data);
1245                 nent = ent;
1246         }
1247         oidcpy(&nent->oid, oid);
1248         nent->tree_data = data;
1249         nent->tree_size = size;
1250         nent->ref = 1;
1251         if (!nent->temporary)
1252                 pbase_tree_cache[my_ix] = nent;
1253         return nent;
1254 }
1255
1256 static void pbase_tree_put(struct pbase_tree_cache *cache)
1257 {
1258         if (!cache->temporary) {
1259                 cache->ref--;
1260                 return;
1261         }
1262         free(cache->tree_data);
1263         free(cache);
1264 }
1265
1266 static int name_cmp_len(const char *name)
1267 {
1268         int i;
1269         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
1270                 ;
1271         return i;
1272 }
1273
1274 static void add_pbase_object(struct tree_desc *tree,
1275                              const char *name,
1276                              int cmplen,
1277                              const char *fullname)
1278 {
1279         struct name_entry entry;
1280         int cmp;
1281
1282         while (tree_entry(tree,&entry)) {
1283                 if (S_ISGITLINK(entry.mode))
1284                         continue;
1285                 cmp = tree_entry_len(&entry) != cmplen ? 1 :
1286                       memcmp(name, entry.path, cmplen);
1287                 if (cmp > 0)
1288                         continue;
1289                 if (cmp < 0)
1290                         return;
1291                 if (name[cmplen] != '/') {
1292                         add_object_entry(entry.oid,
1293                                          object_type(entry.mode),
1294                                          fullname, 1);
1295                         return;
1296                 }
1297                 if (S_ISDIR(entry.mode)) {
1298                         struct tree_desc sub;
1299                         struct pbase_tree_cache *tree;
1300                         const char *down = name+cmplen+1;
1301                         int downlen = name_cmp_len(down);
1302
1303                         tree = pbase_tree_get(entry.oid);
1304                         if (!tree)
1305                                 return;
1306                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1307
1308                         add_pbase_object(&sub, down, downlen, fullname);
1309                         pbase_tree_put(tree);
1310                 }
1311         }
1312 }
1313
1314 static unsigned *done_pbase_paths;
1315 static int done_pbase_paths_num;
1316 static int done_pbase_paths_alloc;
1317 static int done_pbase_path_pos(unsigned hash)
1318 {
1319         int lo = 0;
1320         int hi = done_pbase_paths_num;
1321         while (lo < hi) {
1322                 int mi = lo + (hi - lo) / 2;
1323                 if (done_pbase_paths[mi] == hash)
1324                         return mi;
1325                 if (done_pbase_paths[mi] < hash)
1326                         hi = mi;
1327                 else
1328                         lo = mi + 1;
1329         }
1330         return -lo-1;
1331 }
1332
1333 static int check_pbase_path(unsigned hash)
1334 {
1335         int pos = done_pbase_path_pos(hash);
1336         if (0 <= pos)
1337                 return 1;
1338         pos = -pos - 1;
1339         ALLOC_GROW(done_pbase_paths,
1340                    done_pbase_paths_num + 1,
1341                    done_pbase_paths_alloc);
1342         done_pbase_paths_num++;
1343         if (pos < done_pbase_paths_num)
1344                 MOVE_ARRAY(done_pbase_paths + pos + 1, done_pbase_paths + pos,
1345                            done_pbase_paths_num - pos - 1);
1346         done_pbase_paths[pos] = hash;
1347         return 0;
1348 }
1349
1350 static void add_preferred_base_object(const char *name)
1351 {
1352         struct pbase_tree *it;
1353         int cmplen;
1354         unsigned hash = pack_name_hash(name);
1355
1356         if (!num_preferred_base || check_pbase_path(hash))
1357                 return;
1358
1359         cmplen = name_cmp_len(name);
1360         for (it = pbase_tree; it; it = it->next) {
1361                 if (cmplen == 0) {
1362                         add_object_entry(&it->pcache.oid, OBJ_TREE, NULL, 1);
1363                 }
1364                 else {
1365                         struct tree_desc tree;
1366                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1367                         add_pbase_object(&tree, name, cmplen, name);
1368                 }
1369         }
1370 }
1371
1372 static void add_preferred_base(struct object_id *oid)
1373 {
1374         struct pbase_tree *it;
1375         void *data;
1376         unsigned long size;
1377         struct object_id tree_oid;
1378
1379         if (window <= num_preferred_base++)
1380                 return;
1381
1382         data = read_object_with_reference(oid, tree_type, &size, &tree_oid);
1383         if (!data)
1384                 return;
1385
1386         for (it = pbase_tree; it; it = it->next) {
1387                 if (!oidcmp(&it->pcache.oid, &tree_oid)) {
1388                         free(data);
1389                         return;
1390                 }
1391         }
1392
1393         it = xcalloc(1, sizeof(*it));
1394         it->next = pbase_tree;
1395         pbase_tree = it;
1396
1397         oidcpy(&it->pcache.oid, &tree_oid);
1398         it->pcache.tree_data = data;
1399         it->pcache.tree_size = size;
1400 }
1401
1402 static void cleanup_preferred_base(void)
1403 {
1404         struct pbase_tree *it;
1405         unsigned i;
1406
1407         it = pbase_tree;
1408         pbase_tree = NULL;
1409         while (it) {
1410                 struct pbase_tree *tmp = it;
1411                 it = tmp->next;
1412                 free(tmp->pcache.tree_data);
1413                 free(tmp);
1414         }
1415
1416         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1417                 if (!pbase_tree_cache[i])
1418                         continue;
1419                 free(pbase_tree_cache[i]->tree_data);
1420                 FREE_AND_NULL(pbase_tree_cache[i]);
1421         }
1422
1423         FREE_AND_NULL(done_pbase_paths);
1424         done_pbase_paths_num = done_pbase_paths_alloc = 0;
1425 }
1426
1427 static void check_object(struct object_entry *entry)
1428 {
1429         unsigned long canonical_size;
1430
1431         if (IN_PACK(entry)) {
1432                 struct packed_git *p = IN_PACK(entry);
1433                 struct pack_window *w_curs = NULL;
1434                 const unsigned char *base_ref = NULL;
1435                 struct object_entry *base_entry;
1436                 unsigned long used, used_0;
1437                 unsigned long avail;
1438                 off_t ofs;
1439                 unsigned char *buf, c;
1440                 enum object_type type;
1441                 unsigned long in_pack_size;
1442
1443                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1444
1445                 /*
1446                  * We want in_pack_type even if we do not reuse delta
1447                  * since non-delta representations could still be reused.
1448                  */
1449                 used = unpack_object_header_buffer(buf, avail,
1450                                                    &type,
1451                                                    &in_pack_size);
1452                 if (used == 0)
1453                         goto give_up;
1454
1455                 if (type < 0)
1456                         BUG("invalid type %d", type);
1457                 entry->in_pack_type = type;
1458
1459                 /*
1460                  * Determine if this is a delta and if so whether we can
1461                  * reuse it or not.  Otherwise let's find out as cheaply as
1462                  * possible what the actual type and size for this object is.
1463                  */
1464                 switch (entry->in_pack_type) {
1465                 default:
1466                         /* Not a delta hence we've already got all we need. */
1467                         oe_set_type(entry, entry->in_pack_type);
1468                         SET_SIZE(entry, in_pack_size);
1469                         entry->in_pack_header_size = used;
1470                         if (oe_type(entry) < OBJ_COMMIT || oe_type(entry) > OBJ_BLOB)
1471                                 goto give_up;
1472                         unuse_pack(&w_curs);
1473                         return;
1474                 case OBJ_REF_DELTA:
1475                         if (reuse_delta && !entry->preferred_base)
1476                                 base_ref = use_pack(p, &w_curs,
1477                                                 entry->in_pack_offset + used, NULL);
1478                         entry->in_pack_header_size = used + the_hash_algo->rawsz;
1479                         break;
1480                 case OBJ_OFS_DELTA:
1481                         buf = use_pack(p, &w_curs,
1482                                        entry->in_pack_offset + used, NULL);
1483                         used_0 = 0;
1484                         c = buf[used_0++];
1485                         ofs = c & 127;
1486                         while (c & 128) {
1487                                 ofs += 1;
1488                                 if (!ofs || MSB(ofs, 7)) {
1489                                         error(_("delta base offset overflow in pack for %s"),
1490                                               oid_to_hex(&entry->idx.oid));
1491                                         goto give_up;
1492                                 }
1493                                 c = buf[used_0++];
1494                                 ofs = (ofs << 7) + (c & 127);
1495                         }
1496                         ofs = entry->in_pack_offset - ofs;
1497                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1498                                 error(_("delta base offset out of bound for %s"),
1499                                       oid_to_hex(&entry->idx.oid));
1500                                 goto give_up;
1501                         }
1502                         if (reuse_delta && !entry->preferred_base) {
1503                                 struct revindex_entry *revidx;
1504                                 revidx = find_pack_revindex(p, ofs);
1505                                 if (!revidx)
1506                                         goto give_up;
1507                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1508                         }
1509                         entry->in_pack_header_size = used + used_0;
1510                         break;
1511                 }
1512
1513                 if (base_ref && (base_entry = packlist_find(&to_pack, base_ref, NULL))) {
1514                         /*
1515                          * If base_ref was set above that means we wish to
1516                          * reuse delta data, and we even found that base
1517                          * in the list of objects we want to pack. Goodie!
1518                          *
1519                          * Depth value does not matter - find_deltas() will
1520                          * never consider reused delta as the base object to
1521                          * deltify other objects against, in order to avoid
1522                          * circular deltas.
1523                          */
1524                         oe_set_type(entry, entry->in_pack_type);
1525                         SET_SIZE(entry, in_pack_size); /* delta size */
1526                         SET_DELTA(entry, base_entry);
1527                         SET_DELTA_SIZE(entry, in_pack_size);
1528                         entry->delta_sibling_idx = base_entry->delta_child_idx;
1529                         SET_DELTA_CHILD(base_entry, entry);
1530                         unuse_pack(&w_curs);
1531                         return;
1532                 }
1533
1534                 if (oe_type(entry)) {
1535                         off_t delta_pos;
1536
1537                         /*
1538                          * This must be a delta and we already know what the
1539                          * final object type is.  Let's extract the actual
1540                          * object size from the delta header.
1541                          */
1542                         delta_pos = entry->in_pack_offset + entry->in_pack_header_size;
1543                         canonical_size = get_size_from_delta(p, &w_curs, delta_pos);
1544                         if (canonical_size == 0)
1545                                 goto give_up;
1546                         SET_SIZE(entry, canonical_size);
1547                         unuse_pack(&w_curs);
1548                         return;
1549                 }
1550
1551                 /*
1552                  * No choice but to fall back to the recursive delta walk
1553                  * with sha1_object_info() to find about the object type
1554                  * at this point...
1555                  */
1556                 give_up:
1557                 unuse_pack(&w_curs);
1558         }
1559
1560         oe_set_type(entry,
1561                     oid_object_info(the_repository, &entry->idx.oid, &canonical_size));
1562         if (entry->type_valid) {
1563                 SET_SIZE(entry, canonical_size);
1564         } else {
1565                 /*
1566                  * Bad object type is checked in prepare_pack().  This is
1567                  * to permit a missing preferred base object to be ignored
1568                  * as a preferred base.  Doing so can result in a larger
1569                  * pack file, but the transfer will still take place.
1570                  */
1571         }
1572 }
1573
1574 static int pack_offset_sort(const void *_a, const void *_b)
1575 {
1576         const struct object_entry *a = *(struct object_entry **)_a;
1577         const struct object_entry *b = *(struct object_entry **)_b;
1578         const struct packed_git *a_in_pack = IN_PACK(a);
1579         const struct packed_git *b_in_pack = IN_PACK(b);
1580
1581         /* avoid filesystem trashing with loose objects */
1582         if (!a_in_pack && !b_in_pack)
1583                 return oidcmp(&a->idx.oid, &b->idx.oid);
1584
1585         if (a_in_pack < b_in_pack)
1586                 return -1;
1587         if (a_in_pack > b_in_pack)
1588                 return 1;
1589         return a->in_pack_offset < b->in_pack_offset ? -1 :
1590                         (a->in_pack_offset > b->in_pack_offset);
1591 }
1592
1593 /*
1594  * Drop an on-disk delta we were planning to reuse. Naively, this would
1595  * just involve blanking out the "delta" field, but we have to deal
1596  * with some extra book-keeping:
1597  *
1598  *   1. Removing ourselves from the delta_sibling linked list.
1599  *
1600  *   2. Updating our size/type to the non-delta representation. These were
1601  *      either not recorded initially (size) or overwritten with the delta type
1602  *      (type) when check_object() decided to reuse the delta.
1603  *
1604  *   3. Resetting our delta depth, as we are now a base object.
1605  */
1606 static void drop_reused_delta(struct object_entry *entry)
1607 {
1608         unsigned *idx = &to_pack.objects[entry->delta_idx - 1].delta_child_idx;
1609         struct object_info oi = OBJECT_INFO_INIT;
1610         enum object_type type;
1611         unsigned long size;
1612
1613         while (*idx) {
1614                 struct object_entry *oe = &to_pack.objects[*idx - 1];
1615
1616                 if (oe == entry)
1617                         *idx = oe->delta_sibling_idx;
1618                 else
1619                         idx = &oe->delta_sibling_idx;
1620         }
1621         SET_DELTA(entry, NULL);
1622         entry->depth = 0;
1623
1624         oi.sizep = &size;
1625         oi.typep = &type;
1626         if (packed_object_info(the_repository, IN_PACK(entry), entry->in_pack_offset, &oi) < 0) {
1627                 /*
1628                  * We failed to get the info from this pack for some reason;
1629                  * fall back to sha1_object_info, which may find another copy.
1630                  * And if that fails, the error will be recorded in oe_type(entry)
1631                  * and dealt with in prepare_pack().
1632                  */
1633                 oe_set_type(entry,
1634                             oid_object_info(the_repository, &entry->idx.oid, &size));
1635         } else {
1636                 oe_set_type(entry, type);
1637         }
1638         SET_SIZE(entry, size);
1639 }
1640
1641 /*
1642  * Follow the chain of deltas from this entry onward, throwing away any links
1643  * that cause us to hit a cycle (as determined by the DFS state flags in
1644  * the entries).
1645  *
1646  * We also detect too-long reused chains that would violate our --depth
1647  * limit.
1648  */
1649 static void break_delta_chains(struct object_entry *entry)
1650 {
1651         /*
1652          * The actual depth of each object we will write is stored as an int,
1653          * as it cannot exceed our int "depth" limit. But before we break
1654          * changes based no that limit, we may potentially go as deep as the
1655          * number of objects, which is elsewhere bounded to a uint32_t.
1656          */
1657         uint32_t total_depth;
1658         struct object_entry *cur, *next;
1659
1660         for (cur = entry, total_depth = 0;
1661              cur;
1662              cur = DELTA(cur), total_depth++) {
1663                 if (cur->dfs_state == DFS_DONE) {
1664                         /*
1665                          * We've already seen this object and know it isn't
1666                          * part of a cycle. We do need to append its depth
1667                          * to our count.
1668                          */
1669                         total_depth += cur->depth;
1670                         break;
1671                 }
1672
1673                 /*
1674                  * We break cycles before looping, so an ACTIVE state (or any
1675                  * other cruft which made its way into the state variable)
1676                  * is a bug.
1677                  */
1678                 if (cur->dfs_state != DFS_NONE)
1679                         BUG("confusing delta dfs state in first pass: %d",
1680                             cur->dfs_state);
1681
1682                 /*
1683                  * Now we know this is the first time we've seen the object. If
1684                  * it's not a delta, we're done traversing, but we'll mark it
1685                  * done to save time on future traversals.
1686                  */
1687                 if (!DELTA(cur)) {
1688                         cur->dfs_state = DFS_DONE;
1689                         break;
1690                 }
1691
1692                 /*
1693                  * Mark ourselves as active and see if the next step causes
1694                  * us to cycle to another active object. It's important to do
1695                  * this _before_ we loop, because it impacts where we make the
1696                  * cut, and thus how our total_depth counter works.
1697                  * E.g., We may see a partial loop like:
1698                  *
1699                  *   A -> B -> C -> D -> B
1700                  *
1701                  * Cutting B->C breaks the cycle. But now the depth of A is
1702                  * only 1, and our total_depth counter is at 3. The size of the
1703                  * error is always one less than the size of the cycle we
1704                  * broke. Commits C and D were "lost" from A's chain.
1705                  *
1706                  * If we instead cut D->B, then the depth of A is correct at 3.
1707                  * We keep all commits in the chain that we examined.
1708                  */
1709                 cur->dfs_state = DFS_ACTIVE;
1710                 if (DELTA(cur)->dfs_state == DFS_ACTIVE) {
1711                         drop_reused_delta(cur);
1712                         cur->dfs_state = DFS_DONE;
1713                         break;
1714                 }
1715         }
1716
1717         /*
1718          * And now that we've gone all the way to the bottom of the chain, we
1719          * need to clear the active flags and set the depth fields as
1720          * appropriate. Unlike the loop above, which can quit when it drops a
1721          * delta, we need to keep going to look for more depth cuts. So we need
1722          * an extra "next" pointer to keep going after we reset cur->delta.
1723          */
1724         for (cur = entry; cur; cur = next) {
1725                 next = DELTA(cur);
1726
1727                 /*
1728                  * We should have a chain of zero or more ACTIVE states down to
1729                  * a final DONE. We can quit after the DONE, because either it
1730                  * has no bases, or we've already handled them in a previous
1731                  * call.
1732                  */
1733                 if (cur->dfs_state == DFS_DONE)
1734                         break;
1735                 else if (cur->dfs_state != DFS_ACTIVE)
1736                         BUG("confusing delta dfs state in second pass: %d",
1737                             cur->dfs_state);
1738
1739                 /*
1740                  * If the total_depth is more than depth, then we need to snip
1741                  * the chain into two or more smaller chains that don't exceed
1742                  * the maximum depth. Most of the resulting chains will contain
1743                  * (depth + 1) entries (i.e., depth deltas plus one base), and
1744                  * the last chain (i.e., the one containing entry) will contain
1745                  * whatever entries are left over, namely
1746                  * (total_depth % (depth + 1)) of them.
1747                  *
1748                  * Since we are iterating towards decreasing depth, we need to
1749                  * decrement total_depth as we go, and we need to write to the
1750                  * entry what its final depth will be after all of the
1751                  * snipping. Since we're snipping into chains of length (depth
1752                  * + 1) entries, the final depth of an entry will be its
1753                  * original depth modulo (depth + 1). Any time we encounter an
1754                  * entry whose final depth is supposed to be zero, we snip it
1755                  * from its delta base, thereby making it so.
1756                  */
1757                 cur->depth = (total_depth--) % (depth + 1);
1758                 if (!cur->depth)
1759                         drop_reused_delta(cur);
1760
1761                 cur->dfs_state = DFS_DONE;
1762         }
1763 }
1764
1765 static void get_object_details(void)
1766 {
1767         uint32_t i;
1768         struct object_entry **sorted_by_offset;
1769
1770         if (progress)
1771                 progress_state = start_progress(_("Counting objects"),
1772                                                 to_pack.nr_objects);
1773
1774         sorted_by_offset = xcalloc(to_pack.nr_objects, sizeof(struct object_entry *));
1775         for (i = 0; i < to_pack.nr_objects; i++)
1776                 sorted_by_offset[i] = to_pack.objects + i;
1777         QSORT(sorted_by_offset, to_pack.nr_objects, pack_offset_sort);
1778
1779         for (i = 0; i < to_pack.nr_objects; i++) {
1780                 struct object_entry *entry = sorted_by_offset[i];
1781                 check_object(entry);
1782                 if (entry->type_valid &&
1783                     oe_size_greater_than(&to_pack, entry, big_file_threshold))
1784                         entry->no_try_delta = 1;
1785                 display_progress(progress_state, i + 1);
1786         }
1787         stop_progress(&progress_state);
1788
1789         /*
1790          * This must happen in a second pass, since we rely on the delta
1791          * information for the whole list being completed.
1792          */
1793         for (i = 0; i < to_pack.nr_objects; i++)
1794                 break_delta_chains(&to_pack.objects[i]);
1795
1796         free(sorted_by_offset);
1797 }
1798
1799 /*
1800  * We search for deltas in a list sorted by type, by filename hash, and then
1801  * by size, so that we see progressively smaller and smaller files.
1802  * That's because we prefer deltas to be from the bigger file
1803  * to the smaller -- deletes are potentially cheaper, but perhaps
1804  * more importantly, the bigger file is likely the more recent
1805  * one.  The deepest deltas are therefore the oldest objects which are
1806  * less susceptible to be accessed often.
1807  */
1808 static int type_size_sort(const void *_a, const void *_b)
1809 {
1810         const struct object_entry *a = *(struct object_entry **)_a;
1811         const struct object_entry *b = *(struct object_entry **)_b;
1812         enum object_type a_type = oe_type(a);
1813         enum object_type b_type = oe_type(b);
1814         unsigned long a_size = SIZE(a);
1815         unsigned long b_size = SIZE(b);
1816
1817         if (a_type > b_type)
1818                 return -1;
1819         if (a_type < b_type)
1820                 return 1;
1821         if (a->hash > b->hash)
1822                 return -1;
1823         if (a->hash < b->hash)
1824                 return 1;
1825         if (a->preferred_base > b->preferred_base)
1826                 return -1;
1827         if (a->preferred_base < b->preferred_base)
1828                 return 1;
1829         if (a_size > b_size)
1830                 return -1;
1831         if (a_size < b_size)
1832                 return 1;
1833         return a < b ? -1 : (a > b);  /* newest first */
1834 }
1835
1836 struct unpacked {
1837         struct object_entry *entry;
1838         void *data;
1839         struct delta_index *index;
1840         unsigned depth;
1841 };
1842
1843 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1844                            unsigned long delta_size)
1845 {
1846         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1847                 return 0;
1848
1849         if (delta_size < cache_max_small_delta_size)
1850                 return 1;
1851
1852         /* cache delta, if objects are large enough compared to delta size */
1853         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1854                 return 1;
1855
1856         return 0;
1857 }
1858
1859 #ifndef NO_PTHREADS
1860
1861 /* Protect access to object database */
1862 static pthread_mutex_t read_mutex;
1863 #define read_lock()             pthread_mutex_lock(&read_mutex)
1864 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1865
1866 /* Protect delta_cache_size */
1867 static pthread_mutex_t cache_mutex;
1868 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1869 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1870
1871 /*
1872  * Protect object list partitioning (e.g. struct thread_param) and
1873  * progress_state
1874  */
1875 static pthread_mutex_t progress_mutex;
1876 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1877 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1878
1879 /*
1880  * Access to struct object_entry is unprotected since each thread owns
1881  * a portion of the main object list. Just don't access object entries
1882  * ahead in the list because they can be stolen and would need
1883  * progress_mutex for protection.
1884  */
1885 #else
1886
1887 #define read_lock()             (void)0
1888 #define read_unlock()           (void)0
1889 #define cache_lock()            (void)0
1890 #define cache_unlock()          (void)0
1891 #define progress_lock()         (void)0
1892 #define progress_unlock()       (void)0
1893
1894 #endif
1895
1896 /*
1897  * Return the size of the object without doing any delta
1898  * reconstruction (so non-deltas are true object sizes, but deltas
1899  * return the size of the delta data).
1900  */
1901 unsigned long oe_get_size_slow(struct packing_data *pack,
1902                                const struct object_entry *e)
1903 {
1904         struct packed_git *p;
1905         struct pack_window *w_curs;
1906         unsigned char *buf;
1907         enum object_type type;
1908         unsigned long used, avail, size;
1909
1910         if (e->type_ != OBJ_OFS_DELTA && e->type_ != OBJ_REF_DELTA) {
1911                 read_lock();
1912                 if (oid_object_info(the_repository, &e->idx.oid, &size) < 0)
1913                         die(_("unable to get size of %s"),
1914                             oid_to_hex(&e->idx.oid));
1915                 read_unlock();
1916                 return size;
1917         }
1918
1919         p = oe_in_pack(pack, e);
1920         if (!p)
1921                 BUG("when e->type is a delta, it must belong to a pack");
1922
1923         read_lock();
1924         w_curs = NULL;
1925         buf = use_pack(p, &w_curs, e->in_pack_offset, &avail);
1926         used = unpack_object_header_buffer(buf, avail, &type, &size);
1927         if (used == 0)
1928                 die(_("unable to parse object header of %s"),
1929                     oid_to_hex(&e->idx.oid));
1930
1931         unuse_pack(&w_curs);
1932         read_unlock();
1933         return size;
1934 }
1935
1936 static int try_delta(struct unpacked *trg, struct unpacked *src,
1937                      unsigned max_depth, unsigned long *mem_usage)
1938 {
1939         struct object_entry *trg_entry = trg->entry;
1940         struct object_entry *src_entry = src->entry;
1941         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1942         unsigned ref_depth;
1943         enum object_type type;
1944         void *delta_buf;
1945
1946         /* Don't bother doing diffs between different types */
1947         if (oe_type(trg_entry) != oe_type(src_entry))
1948                 return -1;
1949
1950         /*
1951          * We do not bother to try a delta that we discarded on an
1952          * earlier try, but only when reusing delta data.  Note that
1953          * src_entry that is marked as the preferred_base should always
1954          * be considered, as even if we produce a suboptimal delta against
1955          * it, we will still save the transfer cost, as we already know
1956          * the other side has it and we won't send src_entry at all.
1957          */
1958         if (reuse_delta && IN_PACK(trg_entry) &&
1959             IN_PACK(trg_entry) == IN_PACK(src_entry) &&
1960             !src_entry->preferred_base &&
1961             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1962             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1963                 return 0;
1964
1965         /* Let's not bust the allowed depth. */
1966         if (src->depth >= max_depth)
1967                 return 0;
1968
1969         /* Now some size filtering heuristics. */
1970         trg_size = SIZE(trg_entry);
1971         if (!DELTA(trg_entry)) {
1972                 max_size = trg_size/2 - the_hash_algo->rawsz;
1973                 ref_depth = 1;
1974         } else {
1975                 max_size = DELTA_SIZE(trg_entry);
1976                 ref_depth = trg->depth;
1977         }
1978         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1979                                                 (max_depth - ref_depth + 1);
1980         if (max_size == 0)
1981                 return 0;
1982         src_size = SIZE(src_entry);
1983         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1984         if (sizediff >= max_size)
1985                 return 0;
1986         if (trg_size < src_size / 32)
1987                 return 0;
1988
1989         /* Load data if not already done */
1990         if (!trg->data) {
1991                 read_lock();
1992                 trg->data = read_object_file(&trg_entry->idx.oid, &type, &sz);
1993                 read_unlock();
1994                 if (!trg->data)
1995                         die(_("object %s cannot be read"),
1996                             oid_to_hex(&trg_entry->idx.oid));
1997                 if (sz != trg_size)
1998                         die(_("object %s inconsistent object length (%lu vs %lu)"),
1999                             oid_to_hex(&trg_entry->idx.oid), sz,
2000                             trg_size);
2001                 *mem_usage += sz;
2002         }
2003         if (!src->data) {
2004                 read_lock();
2005                 src->data = read_object_file(&src_entry->idx.oid, &type, &sz);
2006                 read_unlock();
2007                 if (!src->data) {
2008                         if (src_entry->preferred_base) {
2009                                 static int warned = 0;
2010                                 if (!warned++)
2011                                         warning(_("object %s cannot be read"),
2012                                                 oid_to_hex(&src_entry->idx.oid));
2013                                 /*
2014                                  * Those objects are not included in the
2015                                  * resulting pack.  Be resilient and ignore
2016                                  * them if they can't be read, in case the
2017                                  * pack could be created nevertheless.
2018                                  */
2019                                 return 0;
2020                         }
2021                         die(_("object %s cannot be read"),
2022                             oid_to_hex(&src_entry->idx.oid));
2023                 }
2024                 if (sz != src_size)
2025                         die(_("object %s inconsistent object length (%lu vs %lu)"),
2026                             oid_to_hex(&src_entry->idx.oid), sz,
2027                             src_size);
2028                 *mem_usage += sz;
2029         }
2030         if (!src->index) {
2031                 src->index = create_delta_index(src->data, src_size);
2032                 if (!src->index) {
2033                         static int warned = 0;
2034                         if (!warned++)
2035                                 warning(_("suboptimal pack - out of memory"));
2036                         return 0;
2037                 }
2038                 *mem_usage += sizeof_delta_index(src->index);
2039         }
2040
2041         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
2042         if (!delta_buf)
2043                 return 0;
2044
2045         if (DELTA(trg_entry)) {
2046                 /* Prefer only shallower same-sized deltas. */
2047                 if (delta_size == DELTA_SIZE(trg_entry) &&
2048                     src->depth + 1 >= trg->depth) {
2049                         free(delta_buf);
2050                         return 0;
2051                 }
2052         }
2053
2054         /*
2055          * Handle memory allocation outside of the cache
2056          * accounting lock.  Compiler will optimize the strangeness
2057          * away when NO_PTHREADS is defined.
2058          */
2059         free(trg_entry->delta_data);
2060         cache_lock();
2061         if (trg_entry->delta_data) {
2062                 delta_cache_size -= DELTA_SIZE(trg_entry);
2063                 trg_entry->delta_data = NULL;
2064         }
2065         if (delta_cacheable(src_size, trg_size, delta_size)) {
2066                 delta_cache_size += delta_size;
2067                 cache_unlock();
2068                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
2069         } else {
2070                 cache_unlock();
2071                 free(delta_buf);
2072         }
2073
2074         SET_DELTA(trg_entry, src_entry);
2075         SET_DELTA_SIZE(trg_entry, delta_size);
2076         trg->depth = src->depth + 1;
2077
2078         return 1;
2079 }
2080
2081 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
2082 {
2083         struct object_entry *child = DELTA_CHILD(me);
2084         unsigned int m = n;
2085         while (child) {
2086                 unsigned int c = check_delta_limit(child, n + 1);
2087                 if (m < c)
2088                         m = c;
2089                 child = DELTA_SIBLING(child);
2090         }
2091         return m;
2092 }
2093
2094 static unsigned long free_unpacked(struct unpacked *n)
2095 {
2096         unsigned long freed_mem = sizeof_delta_index(n->index);
2097         free_delta_index(n->index);
2098         n->index = NULL;
2099         if (n->data) {
2100                 freed_mem += SIZE(n->entry);
2101                 FREE_AND_NULL(n->data);
2102         }
2103         n->entry = NULL;
2104         n->depth = 0;
2105         return freed_mem;
2106 }
2107
2108 static void find_deltas(struct object_entry **list, unsigned *list_size,
2109                         int window, int depth, unsigned *processed)
2110 {
2111         uint32_t i, idx = 0, count = 0;
2112         struct unpacked *array;
2113         unsigned long mem_usage = 0;
2114
2115         array = xcalloc(window, sizeof(struct unpacked));
2116
2117         for (;;) {
2118                 struct object_entry *entry;
2119                 struct unpacked *n = array + idx;
2120                 int j, max_depth, best_base = -1;
2121
2122                 progress_lock();
2123                 if (!*list_size) {
2124                         progress_unlock();
2125                         break;
2126                 }
2127                 entry = *list++;
2128                 (*list_size)--;
2129                 if (!entry->preferred_base) {
2130                         (*processed)++;
2131                         display_progress(progress_state, *processed);
2132                 }
2133                 progress_unlock();
2134
2135                 mem_usage -= free_unpacked(n);
2136                 n->entry = entry;
2137
2138                 while (window_memory_limit &&
2139                        mem_usage > window_memory_limit &&
2140                        count > 1) {
2141                         uint32_t tail = (idx + window - count) % window;
2142                         mem_usage -= free_unpacked(array + tail);
2143                         count--;
2144                 }
2145
2146                 /* We do not compute delta to *create* objects we are not
2147                  * going to pack.
2148                  */
2149                 if (entry->preferred_base)
2150                         goto next;
2151
2152                 /*
2153                  * If the current object is at pack edge, take the depth the
2154                  * objects that depend on the current object into account
2155                  * otherwise they would become too deep.
2156                  */
2157                 max_depth = depth;
2158                 if (DELTA_CHILD(entry)) {
2159                         max_depth -= check_delta_limit(entry, 0);
2160                         if (max_depth <= 0)
2161                                 goto next;
2162                 }
2163
2164                 j = window;
2165                 while (--j > 0) {
2166                         int ret;
2167                         uint32_t other_idx = idx + j;
2168                         struct unpacked *m;
2169                         if (other_idx >= window)
2170                                 other_idx -= window;
2171                         m = array + other_idx;
2172                         if (!m->entry)
2173                                 break;
2174                         ret = try_delta(n, m, max_depth, &mem_usage);
2175                         if (ret < 0)
2176                                 break;
2177                         else if (ret > 0)
2178                                 best_base = other_idx;
2179                 }
2180
2181                 /*
2182                  * If we decided to cache the delta data, then it is best
2183                  * to compress it right away.  First because we have to do
2184                  * it anyway, and doing it here while we're threaded will
2185                  * save a lot of time in the non threaded write phase,
2186                  * as well as allow for caching more deltas within
2187                  * the same cache size limit.
2188                  * ...
2189                  * But only if not writing to stdout, since in that case
2190                  * the network is most likely throttling writes anyway,
2191                  * and therefore it is best to go to the write phase ASAP
2192                  * instead, as we can afford spending more time compressing
2193                  * between writes at that moment.
2194                  */
2195                 if (entry->delta_data && !pack_to_stdout) {
2196                         unsigned long size;
2197
2198                         size = do_compress(&entry->delta_data, DELTA_SIZE(entry));
2199                         if (size < (1U << OE_Z_DELTA_BITS)) {
2200                                 entry->z_delta_size = size;
2201                                 cache_lock();
2202                                 delta_cache_size -= DELTA_SIZE(entry);
2203                                 delta_cache_size += entry->z_delta_size;
2204                                 cache_unlock();
2205                         } else {
2206                                 FREE_AND_NULL(entry->delta_data);
2207                                 entry->z_delta_size = 0;
2208                         }
2209                 }
2210
2211                 /* if we made n a delta, and if n is already at max
2212                  * depth, leaving it in the window is pointless.  we
2213                  * should evict it first.
2214                  */
2215                 if (DELTA(entry) && max_depth <= n->depth)
2216                         continue;
2217
2218                 /*
2219                  * Move the best delta base up in the window, after the
2220                  * currently deltified object, to keep it longer.  It will
2221                  * be the first base object to be attempted next.
2222                  */
2223                 if (DELTA(entry)) {
2224                         struct unpacked swap = array[best_base];
2225                         int dist = (window + idx - best_base) % window;
2226                         int dst = best_base;
2227                         while (dist--) {
2228                                 int src = (dst + 1) % window;
2229                                 array[dst] = array[src];
2230                                 dst = src;
2231                         }
2232                         array[dst] = swap;
2233                 }
2234
2235                 next:
2236                 idx++;
2237                 if (count + 1 < window)
2238                         count++;
2239                 if (idx >= window)
2240                         idx = 0;
2241         }
2242
2243         for (i = 0; i < window; ++i) {
2244                 free_delta_index(array[i].index);
2245                 free(array[i].data);
2246         }
2247         free(array);
2248 }
2249
2250 #ifndef NO_PTHREADS
2251
2252 static void try_to_free_from_threads(size_t size)
2253 {
2254         read_lock();
2255         release_pack_memory(size);
2256         read_unlock();
2257 }
2258
2259 static try_to_free_t old_try_to_free_routine;
2260
2261 /*
2262  * The main object list is split into smaller lists, each is handed to
2263  * one worker.
2264  *
2265  * The main thread waits on the condition that (at least) one of the workers
2266  * has stopped working (which is indicated in the .working member of
2267  * struct thread_params).
2268  *
2269  * When a work thread has completed its work, it sets .working to 0 and
2270  * signals the main thread and waits on the condition that .data_ready
2271  * becomes 1.
2272  *
2273  * The main thread steals half of the work from the worker that has
2274  * most work left to hand it to the idle worker.
2275  */
2276
2277 struct thread_params {
2278         pthread_t thread;
2279         struct object_entry **list;
2280         unsigned list_size;
2281         unsigned remaining;
2282         int window;
2283         int depth;
2284         int working;
2285         int data_ready;
2286         pthread_mutex_t mutex;
2287         pthread_cond_t cond;
2288         unsigned *processed;
2289 };
2290
2291 static pthread_cond_t progress_cond;
2292
2293 /*
2294  * Mutex and conditional variable can't be statically-initialized on Windows.
2295  */
2296 static void init_threaded_search(void)
2297 {
2298         init_recursive_mutex(&read_mutex);
2299         pthread_mutex_init(&cache_mutex, NULL);
2300         pthread_mutex_init(&progress_mutex, NULL);
2301         pthread_cond_init(&progress_cond, NULL);
2302         pthread_mutex_init(&to_pack.lock, NULL);
2303         old_try_to_free_routine = set_try_to_free_routine(try_to_free_from_threads);
2304 }
2305
2306 static void cleanup_threaded_search(void)
2307 {
2308         set_try_to_free_routine(old_try_to_free_routine);
2309         pthread_cond_destroy(&progress_cond);
2310         pthread_mutex_destroy(&read_mutex);
2311         pthread_mutex_destroy(&cache_mutex);
2312         pthread_mutex_destroy(&progress_mutex);
2313 }
2314
2315 static void *threaded_find_deltas(void *arg)
2316 {
2317         struct thread_params *me = arg;
2318
2319         progress_lock();
2320         while (me->remaining) {
2321                 progress_unlock();
2322
2323                 find_deltas(me->list, &me->remaining,
2324                             me->window, me->depth, me->processed);
2325
2326                 progress_lock();
2327                 me->working = 0;
2328                 pthread_cond_signal(&progress_cond);
2329                 progress_unlock();
2330
2331                 /*
2332                  * We must not set ->data_ready before we wait on the
2333                  * condition because the main thread may have set it to 1
2334                  * before we get here. In order to be sure that new
2335                  * work is available if we see 1 in ->data_ready, it
2336                  * was initialized to 0 before this thread was spawned
2337                  * and we reset it to 0 right away.
2338                  */
2339                 pthread_mutex_lock(&me->mutex);
2340                 while (!me->data_ready)
2341                         pthread_cond_wait(&me->cond, &me->mutex);
2342                 me->data_ready = 0;
2343                 pthread_mutex_unlock(&me->mutex);
2344
2345                 progress_lock();
2346         }
2347         progress_unlock();
2348         /* leave ->working 1 so that this doesn't get more work assigned */
2349         return NULL;
2350 }
2351
2352 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
2353                            int window, int depth, unsigned *processed)
2354 {
2355         struct thread_params *p;
2356         int i, ret, active_threads = 0;
2357
2358         init_threaded_search();
2359
2360         if (delta_search_threads <= 1) {
2361                 find_deltas(list, &list_size, window, depth, processed);
2362                 cleanup_threaded_search();
2363                 return;
2364         }
2365         if (progress > pack_to_stdout)
2366                 fprintf_ln(stderr, _("Delta compression using up to %d threads"),
2367                            delta_search_threads);
2368         p = xcalloc(delta_search_threads, sizeof(*p));
2369
2370         /* Partition the work amongst work threads. */
2371         for (i = 0; i < delta_search_threads; i++) {
2372                 unsigned sub_size = list_size / (delta_search_threads - i);
2373
2374                 /* don't use too small segments or no deltas will be found */
2375                 if (sub_size < 2*window && i+1 < delta_search_threads)
2376                         sub_size = 0;
2377
2378                 p[i].window = window;
2379                 p[i].depth = depth;
2380                 p[i].processed = processed;
2381                 p[i].working = 1;
2382                 p[i].data_ready = 0;
2383
2384                 /* try to split chunks on "path" boundaries */
2385                 while (sub_size && sub_size < list_size &&
2386                        list[sub_size]->hash &&
2387                        list[sub_size]->hash == list[sub_size-1]->hash)
2388                         sub_size++;
2389
2390                 p[i].list = list;
2391                 p[i].list_size = sub_size;
2392                 p[i].remaining = sub_size;
2393
2394                 list += sub_size;
2395                 list_size -= sub_size;
2396         }
2397
2398         /* Start work threads. */
2399         for (i = 0; i < delta_search_threads; i++) {
2400                 if (!p[i].list_size)
2401                         continue;
2402                 pthread_mutex_init(&p[i].mutex, NULL);
2403                 pthread_cond_init(&p[i].cond, NULL);
2404                 ret = pthread_create(&p[i].thread, NULL,
2405                                      threaded_find_deltas, &p[i]);
2406                 if (ret)
2407                         die(_("unable to create thread: %s"), strerror(ret));
2408                 active_threads++;
2409         }
2410
2411         /*
2412          * Now let's wait for work completion.  Each time a thread is done
2413          * with its work, we steal half of the remaining work from the
2414          * thread with the largest number of unprocessed objects and give
2415          * it to that newly idle thread.  This ensure good load balancing
2416          * until the remaining object list segments are simply too short
2417          * to be worth splitting anymore.
2418          */
2419         while (active_threads) {
2420                 struct thread_params *target = NULL;
2421                 struct thread_params *victim = NULL;
2422                 unsigned sub_size = 0;
2423
2424                 progress_lock();
2425                 for (;;) {
2426                         for (i = 0; !target && i < delta_search_threads; i++)
2427                                 if (!p[i].working)
2428                                         target = &p[i];
2429                         if (target)
2430                                 break;
2431                         pthread_cond_wait(&progress_cond, &progress_mutex);
2432                 }
2433
2434                 for (i = 0; i < delta_search_threads; i++)
2435                         if (p[i].remaining > 2*window &&
2436                             (!victim || victim->remaining < p[i].remaining))
2437                                 victim = &p[i];
2438                 if (victim) {
2439                         sub_size = victim->remaining / 2;
2440                         list = victim->list + victim->list_size - sub_size;
2441                         while (sub_size && list[0]->hash &&
2442                                list[0]->hash == list[-1]->hash) {
2443                                 list++;
2444                                 sub_size--;
2445                         }
2446                         if (!sub_size) {
2447                                 /*
2448                                  * It is possible for some "paths" to have
2449                                  * so many objects that no hash boundary
2450                                  * might be found.  Let's just steal the
2451                                  * exact half in that case.
2452                                  */
2453                                 sub_size = victim->remaining / 2;
2454                                 list -= sub_size;
2455                         }
2456                         target->list = list;
2457                         victim->list_size -= sub_size;
2458                         victim->remaining -= sub_size;
2459                 }
2460                 target->list_size = sub_size;
2461                 target->remaining = sub_size;
2462                 target->working = 1;
2463                 progress_unlock();
2464
2465                 pthread_mutex_lock(&target->mutex);
2466                 target->data_ready = 1;
2467                 pthread_cond_signal(&target->cond);
2468                 pthread_mutex_unlock(&target->mutex);
2469
2470                 if (!sub_size) {
2471                         pthread_join(target->thread, NULL);
2472                         pthread_cond_destroy(&target->cond);
2473                         pthread_mutex_destroy(&target->mutex);
2474                         active_threads--;
2475                 }
2476         }
2477         cleanup_threaded_search();
2478         free(p);
2479 }
2480
2481 #else
2482 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
2483 #endif
2484
2485 static void add_tag_chain(const struct object_id *oid)
2486 {
2487         struct tag *tag;
2488
2489         /*
2490          * We catch duplicates already in add_object_entry(), but we'd
2491          * prefer to do this extra check to avoid having to parse the
2492          * tag at all if we already know that it's being packed (e.g., if
2493          * it was included via bitmaps, we would not have parsed it
2494          * previously).
2495          */
2496         if (packlist_find(&to_pack, oid->hash, NULL))
2497                 return;
2498
2499         tag = lookup_tag(the_repository, oid);
2500         while (1) {
2501                 if (!tag || parse_tag(tag) || !tag->tagged)
2502                         die(_("unable to pack objects reachable from tag %s"),
2503                             oid_to_hex(oid));
2504
2505                 add_object_entry(&tag->object.oid, OBJ_TAG, NULL, 0);
2506
2507                 if (tag->tagged->type != OBJ_TAG)
2508                         return;
2509
2510                 tag = (struct tag *)tag->tagged;
2511         }
2512 }
2513
2514 static int add_ref_tag(const char *path, const struct object_id *oid, int flag, void *cb_data)
2515 {
2516         struct object_id peeled;
2517
2518         if (starts_with(path, "refs/tags/") && /* is a tag? */
2519             !peel_ref(path, &peeled)    && /* peelable? */
2520             packlist_find(&to_pack, peeled.hash, NULL))      /* object packed? */
2521                 add_tag_chain(oid);
2522         return 0;
2523 }
2524
2525 static void prepare_pack(int window, int depth)
2526 {
2527         struct object_entry **delta_list;
2528         uint32_t i, nr_deltas;
2529         unsigned n;
2530
2531         get_object_details();
2532
2533         /*
2534          * If we're locally repacking then we need to be doubly careful
2535          * from now on in order to make sure no stealth corruption gets
2536          * propagated to the new pack.  Clients receiving streamed packs
2537          * should validate everything they get anyway so no need to incur
2538          * the additional cost here in that case.
2539          */
2540         if (!pack_to_stdout)
2541                 do_check_packed_object_crc = 1;
2542
2543         if (!to_pack.nr_objects || !window || !depth)
2544                 return;
2545
2546         ALLOC_ARRAY(delta_list, to_pack.nr_objects);
2547         nr_deltas = n = 0;
2548
2549         for (i = 0; i < to_pack.nr_objects; i++) {
2550                 struct object_entry *entry = to_pack.objects + i;
2551
2552                 if (DELTA(entry))
2553                         /* This happens if we decided to reuse existing
2554                          * delta from a pack.  "reuse_delta &&" is implied.
2555                          */
2556                         continue;
2557
2558                 if (!entry->type_valid ||
2559                     oe_size_less_than(&to_pack, entry, 50))
2560                         continue;
2561
2562                 if (entry->no_try_delta)
2563                         continue;
2564
2565                 if (!entry->preferred_base) {
2566                         nr_deltas++;
2567                         if (oe_type(entry) < 0)
2568                                 die(_("unable to get type of object %s"),
2569                                     oid_to_hex(&entry->idx.oid));
2570                 } else {
2571                         if (oe_type(entry) < 0) {
2572                                 /*
2573                                  * This object is not found, but we
2574                                  * don't have to include it anyway.
2575                                  */
2576                                 continue;
2577                         }
2578                 }
2579
2580                 delta_list[n++] = entry;
2581         }
2582
2583         if (nr_deltas && n > 1) {
2584                 unsigned nr_done = 0;
2585                 if (progress)
2586                         progress_state = start_progress(_("Compressing objects"),
2587                                                         nr_deltas);
2588                 QSORT(delta_list, n, type_size_sort);
2589                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
2590                 stop_progress(&progress_state);
2591                 if (nr_done != nr_deltas)
2592                         die(_("inconsistency with delta count"));
2593         }
2594         free(delta_list);
2595 }
2596
2597 static int git_pack_config(const char *k, const char *v, void *cb)
2598 {
2599         if (!strcmp(k, "pack.window")) {
2600                 window = git_config_int(k, v);
2601                 return 0;
2602         }
2603         if (!strcmp(k, "pack.windowmemory")) {
2604                 window_memory_limit = git_config_ulong(k, v);
2605                 return 0;
2606         }
2607         if (!strcmp(k, "pack.depth")) {
2608                 depth = git_config_int(k, v);
2609                 return 0;
2610         }
2611         if (!strcmp(k, "pack.deltacachesize")) {
2612                 max_delta_cache_size = git_config_int(k, v);
2613                 return 0;
2614         }
2615         if (!strcmp(k, "pack.deltacachelimit")) {
2616                 cache_max_small_delta_size = git_config_int(k, v);
2617                 return 0;
2618         }
2619         if (!strcmp(k, "pack.writebitmaphashcache")) {
2620                 if (git_config_bool(k, v))
2621                         write_bitmap_options |= BITMAP_OPT_HASH_CACHE;
2622                 else
2623                         write_bitmap_options &= ~BITMAP_OPT_HASH_CACHE;
2624         }
2625         if (!strcmp(k, "pack.usebitmaps")) {
2626                 use_bitmap_index_default = git_config_bool(k, v);
2627                 return 0;
2628         }
2629         if (!strcmp(k, "pack.threads")) {
2630                 delta_search_threads = git_config_int(k, v);
2631                 if (delta_search_threads < 0)
2632                         die(_("invalid number of threads specified (%d)"),
2633                             delta_search_threads);
2634 #ifdef NO_PTHREADS
2635                 if (delta_search_threads != 1) {
2636                         warning(_("no threads support, ignoring %s"), k);
2637                         delta_search_threads = 0;
2638                 }
2639 #endif
2640                 return 0;
2641         }
2642         if (!strcmp(k, "pack.indexversion")) {
2643                 pack_idx_opts.version = git_config_int(k, v);
2644                 if (pack_idx_opts.version > 2)
2645                         die(_("bad pack.indexversion=%"PRIu32),
2646                             pack_idx_opts.version);
2647                 return 0;
2648         }
2649         return git_default_config(k, v, cb);
2650 }
2651
2652 static void read_object_list_from_stdin(void)
2653 {
2654         char line[GIT_MAX_HEXSZ + 1 + PATH_MAX + 2];
2655         struct object_id oid;
2656         const char *p;
2657
2658         for (;;) {
2659                 if (!fgets(line, sizeof(line), stdin)) {
2660                         if (feof(stdin))
2661                                 break;
2662                         if (!ferror(stdin))
2663                                 die("BUG: fgets returned NULL, not EOF, not error!");
2664                         if (errno != EINTR)
2665                                 die_errno("fgets");
2666                         clearerr(stdin);
2667                         continue;
2668                 }
2669                 if (line[0] == '-') {
2670                         if (get_oid_hex(line+1, &oid))
2671                                 die(_("expected edge object ID, got garbage:\n %s"),
2672                                     line);
2673                         add_preferred_base(&oid);
2674                         continue;
2675                 }
2676                 if (parse_oid_hex(line, &oid, &p))
2677                         die(_("expected object ID, got garbage:\n %s"), line);
2678
2679                 add_preferred_base_object(p + 1);
2680                 add_object_entry(&oid, OBJ_NONE, p + 1, 0);
2681         }
2682 }
2683
2684 /* Remember to update object flag allocation in object.h */
2685 #define OBJECT_ADDED (1u<<20)
2686
2687 static void show_commit(struct commit *commit, void *data)
2688 {
2689         add_object_entry(&commit->object.oid, OBJ_COMMIT, NULL, 0);
2690         commit->object.flags |= OBJECT_ADDED;
2691
2692         if (write_bitmap_index)
2693                 index_commit_for_bitmap(commit);
2694 }
2695
2696 static void show_object(struct object *obj, const char *name, void *data)
2697 {
2698         add_preferred_base_object(name);
2699         add_object_entry(&obj->oid, obj->type, name, 0);
2700         obj->flags |= OBJECT_ADDED;
2701 }
2702
2703 static void show_object__ma_allow_any(struct object *obj, const char *name, void *data)
2704 {
2705         assert(arg_missing_action == MA_ALLOW_ANY);
2706
2707         /*
2708          * Quietly ignore ALL missing objects.  This avoids problems with
2709          * staging them now and getting an odd error later.
2710          */
2711         if (!has_object_file(&obj->oid))
2712                 return;
2713
2714         show_object(obj, name, data);
2715 }
2716
2717 static void show_object__ma_allow_promisor(struct object *obj, const char *name, void *data)
2718 {
2719         assert(arg_missing_action == MA_ALLOW_PROMISOR);
2720
2721         /*
2722          * Quietly ignore EXPECTED missing objects.  This avoids problems with
2723          * staging them now and getting an odd error later.
2724          */
2725         if (!has_object_file(&obj->oid) && is_promisor_object(&obj->oid))
2726                 return;
2727
2728         show_object(obj, name, data);
2729 }
2730
2731 static int option_parse_missing_action(const struct option *opt,
2732                                        const char *arg, int unset)
2733 {
2734         assert(arg);
2735         assert(!unset);
2736
2737         if (!strcmp(arg, "error")) {
2738                 arg_missing_action = MA_ERROR;
2739                 fn_show_object = show_object;
2740                 return 0;
2741         }
2742
2743         if (!strcmp(arg, "allow-any")) {
2744                 arg_missing_action = MA_ALLOW_ANY;
2745                 fetch_if_missing = 0;
2746                 fn_show_object = show_object__ma_allow_any;
2747                 return 0;
2748         }
2749
2750         if (!strcmp(arg, "allow-promisor")) {
2751                 arg_missing_action = MA_ALLOW_PROMISOR;
2752                 fetch_if_missing = 0;
2753                 fn_show_object = show_object__ma_allow_promisor;
2754                 return 0;
2755         }
2756
2757         die(_("invalid value for --missing"));
2758         return 0;
2759 }
2760
2761 static void show_edge(struct commit *commit)
2762 {
2763         add_preferred_base(&commit->object.oid);
2764 }
2765
2766 struct in_pack_object {
2767         off_t offset;
2768         struct object *object;
2769 };
2770
2771 struct in_pack {
2772         unsigned int alloc;
2773         unsigned int nr;
2774         struct in_pack_object *array;
2775 };
2776
2777 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
2778 {
2779         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->oid.hash, p);
2780         in_pack->array[in_pack->nr].object = object;
2781         in_pack->nr++;
2782 }
2783
2784 /*
2785  * Compare the objects in the offset order, in order to emulate the
2786  * "git rev-list --objects" output that produced the pack originally.
2787  */
2788 static int ofscmp(const void *a_, const void *b_)
2789 {
2790         struct in_pack_object *a = (struct in_pack_object *)a_;
2791         struct in_pack_object *b = (struct in_pack_object *)b_;
2792
2793         if (a->offset < b->offset)
2794                 return -1;
2795         else if (a->offset > b->offset)
2796                 return 1;
2797         else
2798                 return oidcmp(&a->object->oid, &b->object->oid);
2799 }
2800
2801 static void add_objects_in_unpacked_packs(struct rev_info *revs)
2802 {
2803         struct packed_git *p;
2804         struct in_pack in_pack;
2805         uint32_t i;
2806
2807         memset(&in_pack, 0, sizeof(in_pack));
2808
2809         for (p = get_packed_git(the_repository); p; p = p->next) {
2810                 struct object_id oid;
2811                 struct object *o;
2812
2813                 if (!p->pack_local || p->pack_keep || p->pack_keep_in_core)
2814                         continue;
2815                 if (open_pack_index(p))
2816                         die(_("cannot open pack index"));
2817
2818                 ALLOC_GROW(in_pack.array,
2819                            in_pack.nr + p->num_objects,
2820                            in_pack.alloc);
2821
2822                 for (i = 0; i < p->num_objects; i++) {
2823                         nth_packed_object_oid(&oid, p, i);
2824                         o = lookup_unknown_object(oid.hash);
2825                         if (!(o->flags & OBJECT_ADDED))
2826                                 mark_in_pack_object(o, p, &in_pack);
2827                         o->flags |= OBJECT_ADDED;
2828                 }
2829         }
2830
2831         if (in_pack.nr) {
2832                 QSORT(in_pack.array, in_pack.nr, ofscmp);
2833                 for (i = 0; i < in_pack.nr; i++) {
2834                         struct object *o = in_pack.array[i].object;
2835                         add_object_entry(&o->oid, o->type, "", 0);
2836                 }
2837         }
2838         free(in_pack.array);
2839 }
2840
2841 static int add_loose_object(const struct object_id *oid, const char *path,
2842                             void *data)
2843 {
2844         enum object_type type = oid_object_info(the_repository, oid, NULL);
2845
2846         if (type < 0) {
2847                 warning(_("loose object at %s could not be examined"), path);
2848                 return 0;
2849         }
2850
2851         add_object_entry(oid, type, "", 0);
2852         return 0;
2853 }
2854
2855 /*
2856  * We actually don't even have to worry about reachability here.
2857  * add_object_entry will weed out duplicates, so we just add every
2858  * loose object we find.
2859  */
2860 static void add_unreachable_loose_objects(void)
2861 {
2862         for_each_loose_file_in_objdir(get_object_directory(),
2863                                       add_loose_object,
2864                                       NULL, NULL, NULL);
2865 }
2866
2867 static int has_sha1_pack_kept_or_nonlocal(const struct object_id *oid)
2868 {
2869         static struct packed_git *last_found = (void *)1;
2870         struct packed_git *p;
2871
2872         p = (last_found != (void *)1) ? last_found :
2873                                         get_packed_git(the_repository);
2874
2875         while (p) {
2876                 if ((!p->pack_local || p->pack_keep ||
2877                                 p->pack_keep_in_core) &&
2878                         find_pack_entry_one(oid->hash, p)) {
2879                         last_found = p;
2880                         return 1;
2881                 }
2882                 if (p == last_found)
2883                         p = get_packed_git(the_repository);
2884                 else
2885                         p = p->next;
2886                 if (p == last_found)
2887                         p = p->next;
2888         }
2889         return 0;
2890 }
2891
2892 /*
2893  * Store a list of sha1s that are should not be discarded
2894  * because they are either written too recently, or are
2895  * reachable from another object that was.
2896  *
2897  * This is filled by get_object_list.
2898  */
2899 static struct oid_array recent_objects;
2900
2901 static int loosened_object_can_be_discarded(const struct object_id *oid,
2902                                             timestamp_t mtime)
2903 {
2904         if (!unpack_unreachable_expiration)
2905                 return 0;
2906         if (mtime > unpack_unreachable_expiration)
2907                 return 0;
2908         if (oid_array_lookup(&recent_objects, oid) >= 0)
2909                 return 0;
2910         return 1;
2911 }
2912
2913 static void loosen_unused_packed_objects(struct rev_info *revs)
2914 {
2915         struct packed_git *p;
2916         uint32_t i;
2917         struct object_id oid;
2918
2919         for (p = get_packed_git(the_repository); p; p = p->next) {
2920                 if (!p->pack_local || p->pack_keep || p->pack_keep_in_core)
2921                         continue;
2922
2923                 if (open_pack_index(p))
2924                         die(_("cannot open pack index"));
2925
2926                 for (i = 0; i < p->num_objects; i++) {
2927                         nth_packed_object_oid(&oid, p, i);
2928                         if (!packlist_find(&to_pack, oid.hash, NULL) &&
2929                             !has_sha1_pack_kept_or_nonlocal(&oid) &&
2930                             !loosened_object_can_be_discarded(&oid, p->mtime))
2931                                 if (force_object_loose(&oid, p->mtime))
2932                                         die(_("unable to force loose object"));
2933                 }
2934         }
2935 }
2936
2937 /*
2938  * This tracks any options which pack-reuse code expects to be on, or which a
2939  * reader of the pack might not understand, and which would therefore prevent
2940  * blind reuse of what we have on disk.
2941  */
2942 static int pack_options_allow_reuse(void)
2943 {
2944         return pack_to_stdout &&
2945                allow_ofs_delta &&
2946                !ignore_packed_keep_on_disk &&
2947                !ignore_packed_keep_in_core &&
2948                (!local || !have_non_local_packs) &&
2949                !incremental;
2950 }
2951
2952 static int get_object_list_from_bitmap(struct rev_info *revs)
2953 {
2954         struct bitmap_index *bitmap_git;
2955         if (!(bitmap_git = prepare_bitmap_walk(revs)))
2956                 return -1;
2957
2958         if (pack_options_allow_reuse() &&
2959             !reuse_partial_packfile_from_bitmap(
2960                         bitmap_git,
2961                         &reuse_packfile,
2962                         &reuse_packfile_objects,
2963                         &reuse_packfile_offset)) {
2964                 assert(reuse_packfile_objects);
2965                 nr_result += reuse_packfile_objects;
2966                 display_progress(progress_state, nr_result);
2967         }
2968
2969         traverse_bitmap_commit_list(bitmap_git, &add_object_entry_from_bitmap);
2970         free_bitmap_index(bitmap_git);
2971         return 0;
2972 }
2973
2974 static void record_recent_object(struct object *obj,
2975                                  const char *name,
2976                                  void *data)
2977 {
2978         oid_array_append(&recent_objects, &obj->oid);
2979 }
2980
2981 static void record_recent_commit(struct commit *commit, void *data)
2982 {
2983         oid_array_append(&recent_objects, &commit->object.oid);
2984 }
2985
2986 static void get_object_list(int ac, const char **av)
2987 {
2988         struct rev_info revs;
2989         char line[1000];
2990         int flags = 0;
2991
2992         init_revisions(&revs, NULL);
2993         save_commit_buffer = 0;
2994         setup_revisions(ac, av, &revs, NULL);
2995
2996         /* make sure shallows are read */
2997         is_repository_shallow(the_repository);
2998
2999         while (fgets(line, sizeof(line), stdin) != NULL) {
3000                 int len = strlen(line);
3001                 if (len && line[len - 1] == '\n')
3002                         line[--len] = 0;
3003                 if (!len)
3004                         break;
3005                 if (*line == '-') {
3006                         if (!strcmp(line, "--not")) {
3007                                 flags ^= UNINTERESTING;
3008                                 write_bitmap_index = 0;
3009                                 continue;
3010                         }
3011                         if (starts_with(line, "--shallow ")) {
3012                                 struct object_id oid;
3013                                 if (get_oid_hex(line + 10, &oid))
3014                                         die("not an SHA-1 '%s'", line + 10);
3015                                 register_shallow(the_repository, &oid);
3016                                 use_bitmap_index = 0;
3017                                 continue;
3018                         }
3019                         die(_("not a rev '%s'"), line);
3020                 }
3021                 if (handle_revision_arg(line, &revs, flags, REVARG_CANNOT_BE_FILENAME))
3022                         die(_("bad revision '%s'"), line);
3023         }
3024
3025         if (use_bitmap_index && !get_object_list_from_bitmap(&revs))
3026                 return;
3027
3028         if (prepare_revision_walk(&revs))
3029                 die(_("revision walk setup failed"));
3030         mark_edges_uninteresting(&revs, show_edge);
3031
3032         if (!fn_show_object)
3033                 fn_show_object = show_object;
3034         traverse_commit_list_filtered(&filter_options, &revs,
3035                                       show_commit, fn_show_object, NULL,
3036                                       NULL);
3037
3038         if (unpack_unreachable_expiration) {
3039                 revs.ignore_missing_links = 1;
3040                 if (add_unseen_recent_objects_to_traversal(&revs,
3041                                 unpack_unreachable_expiration))
3042                         die(_("unable to add recent objects"));
3043                 if (prepare_revision_walk(&revs))
3044                         die(_("revision walk setup failed"));
3045                 traverse_commit_list(&revs, record_recent_commit,
3046                                      record_recent_object, NULL);
3047         }
3048
3049         if (keep_unreachable)
3050                 add_objects_in_unpacked_packs(&revs);
3051         if (pack_loose_unreachable)
3052                 add_unreachable_loose_objects();
3053         if (unpack_unreachable)
3054                 loosen_unused_packed_objects(&revs);
3055
3056         oid_array_clear(&recent_objects);
3057 }
3058
3059 static void add_extra_kept_packs(const struct string_list *names)
3060 {
3061         struct packed_git *p;
3062
3063         if (!names->nr)
3064                 return;
3065
3066         for (p = get_packed_git(the_repository); p; p = p->next) {
3067                 const char *name = basename(p->pack_name);
3068                 int i;
3069
3070                 if (!p->pack_local)
3071                         continue;
3072
3073                 for (i = 0; i < names->nr; i++)
3074                         if (!fspathcmp(name, names->items[i].string))
3075                                 break;
3076
3077                 if (i < names->nr) {
3078                         p->pack_keep_in_core = 1;
3079                         ignore_packed_keep_in_core = 1;
3080                         continue;
3081                 }
3082         }
3083 }
3084
3085 static int option_parse_index_version(const struct option *opt,
3086                                       const char *arg, int unset)
3087 {
3088         char *c;
3089         const char *val = arg;
3090         pack_idx_opts.version = strtoul(val, &c, 10);
3091         if (pack_idx_opts.version > 2)
3092                 die(_("unsupported index version %s"), val);
3093         if (*c == ',' && c[1])
3094                 pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
3095         if (*c || pack_idx_opts.off32_limit & 0x80000000)
3096                 die(_("bad index version '%s'"), val);
3097         return 0;
3098 }
3099
3100 static int option_parse_unpack_unreachable(const struct option *opt,
3101                                            const char *arg, int unset)
3102 {
3103         if (unset) {
3104                 unpack_unreachable = 0;
3105                 unpack_unreachable_expiration = 0;
3106         }
3107         else {
3108                 unpack_unreachable = 1;
3109                 if (arg)
3110                         unpack_unreachable_expiration = approxidate(arg);
3111         }
3112         return 0;
3113 }
3114
3115 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
3116 {
3117         int use_internal_rev_list = 0;
3118         int thin = 0;
3119         int shallow = 0;
3120         int all_progress_implied = 0;
3121         struct argv_array rp = ARGV_ARRAY_INIT;
3122         int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
3123         int rev_list_index = 0;
3124         struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
3125         struct option pack_objects_options[] = {
3126                 OPT_SET_INT('q', "quiet", &progress,
3127                             N_("do not show progress meter"), 0),
3128                 OPT_SET_INT(0, "progress", &progress,
3129                             N_("show progress meter"), 1),
3130                 OPT_SET_INT(0, "all-progress", &progress,
3131                             N_("show progress meter during object writing phase"), 2),
3132                 OPT_BOOL(0, "all-progress-implied",
3133                          &all_progress_implied,
3134                          N_("similar to --all-progress when progress meter is shown")),
3135                 { OPTION_CALLBACK, 0, "index-version", NULL, N_("<version>[,<offset>]"),
3136                   N_("write the pack index file in the specified idx format version"),
3137                   0, option_parse_index_version },
3138                 OPT_MAGNITUDE(0, "max-pack-size", &pack_size_limit,
3139                               N_("maximum size of each output pack file")),
3140                 OPT_BOOL(0, "local", &local,
3141                          N_("ignore borrowed objects from alternate object store")),
3142                 OPT_BOOL(0, "incremental", &incremental,
3143                          N_("ignore packed objects")),
3144                 OPT_INTEGER(0, "window", &window,
3145                             N_("limit pack window by objects")),
3146                 OPT_MAGNITUDE(0, "window-memory", &window_memory_limit,
3147                               N_("limit pack window by memory in addition to object limit")),
3148                 OPT_INTEGER(0, "depth", &depth,
3149                             N_("maximum length of delta chain allowed in the resulting pack")),
3150                 OPT_BOOL(0, "reuse-delta", &reuse_delta,
3151                          N_("reuse existing deltas")),
3152                 OPT_BOOL(0, "reuse-object", &reuse_object,
3153                          N_("reuse existing objects")),
3154                 OPT_BOOL(0, "delta-base-offset", &allow_ofs_delta,
3155                          N_("use OFS_DELTA objects")),
3156                 OPT_INTEGER(0, "threads", &delta_search_threads,
3157                             N_("use threads when searching for best delta matches")),
3158                 OPT_BOOL(0, "non-empty", &non_empty,
3159                          N_("do not create an empty pack output")),
3160                 OPT_BOOL(0, "revs", &use_internal_rev_list,
3161                          N_("read revision arguments from standard input")),
3162                 OPT_SET_INT_F(0, "unpacked", &rev_list_unpacked,
3163                               N_("limit the objects to those that are not yet packed"),
3164                               1, PARSE_OPT_NONEG),
3165                 OPT_SET_INT_F(0, "all", &rev_list_all,
3166                               N_("include objects reachable from any reference"),
3167                               1, PARSE_OPT_NONEG),
3168                 OPT_SET_INT_F(0, "reflog", &rev_list_reflog,
3169                               N_("include objects referred by reflog entries"),
3170                               1, PARSE_OPT_NONEG),
3171                 OPT_SET_INT_F(0, "indexed-objects", &rev_list_index,
3172                               N_("include objects referred to by the index"),
3173                               1, PARSE_OPT_NONEG),
3174                 OPT_BOOL(0, "stdout", &pack_to_stdout,
3175                          N_("output pack to stdout")),
3176                 OPT_BOOL(0, "include-tag", &include_tag,
3177                          N_("include tag objects that refer to objects to be packed")),
3178                 OPT_BOOL(0, "keep-unreachable", &keep_unreachable,
3179                          N_("keep unreachable objects")),
3180                 OPT_BOOL(0, "pack-loose-unreachable", &pack_loose_unreachable,
3181                          N_("pack loose unreachable objects")),
3182                 { OPTION_CALLBACK, 0, "unpack-unreachable", NULL, N_("time"),
3183                   N_("unpack unreachable objects newer than <time>"),
3184                   PARSE_OPT_OPTARG, option_parse_unpack_unreachable },
3185                 OPT_BOOL(0, "thin", &thin,
3186                          N_("create thin packs")),
3187                 OPT_BOOL(0, "shallow", &shallow,
3188                          N_("create packs suitable for shallow fetches")),
3189                 OPT_BOOL(0, "honor-pack-keep", &ignore_packed_keep_on_disk,
3190                          N_("ignore packs that have companion .keep file")),
3191                 OPT_STRING_LIST(0, "keep-pack", &keep_pack_list, N_("name"),
3192                                 N_("ignore this pack")),
3193                 OPT_INTEGER(0, "compression", &pack_compression_level,
3194                             N_("pack compression level")),
3195                 OPT_SET_INT(0, "keep-true-parents", &grafts_replace_parents,
3196                             N_("do not hide commits by grafts"), 0),
3197                 OPT_BOOL(0, "use-bitmap-index", &use_bitmap_index,
3198                          N_("use a bitmap index if available to speed up counting objects")),
3199                 OPT_BOOL(0, "write-bitmap-index", &write_bitmap_index,
3200                          N_("write a bitmap index together with the pack index")),
3201                 OPT_PARSE_LIST_OBJECTS_FILTER(&filter_options),
3202                 { OPTION_CALLBACK, 0, "missing", NULL, N_("action"),
3203                   N_("handling for missing objects"), PARSE_OPT_NONEG,
3204                   option_parse_missing_action },
3205                 OPT_BOOL(0, "exclude-promisor-objects", &exclude_promisor_objects,
3206                          N_("do not pack objects in promisor packfiles")),
3207                 OPT_END(),
3208         };
3209
3210         if (DFS_NUM_STATES > (1 << OE_DFS_STATE_BITS))
3211                 BUG("too many dfs states, increase OE_DFS_STATE_BITS");
3212
3213         read_replace_refs = 0;
3214
3215         reset_pack_idx_option(&pack_idx_opts);
3216         git_config(git_pack_config, NULL);
3217
3218         progress = isatty(2);
3219         argc = parse_options(argc, argv, prefix, pack_objects_options,
3220                              pack_usage, 0);
3221
3222         if (argc) {
3223                 base_name = argv[0];
3224                 argc--;
3225         }
3226         if (pack_to_stdout != !base_name || argc)
3227                 usage_with_options(pack_usage, pack_objects_options);
3228
3229         if (depth >= (1 << OE_DEPTH_BITS)) {
3230                 warning(_("delta chain depth %d is too deep, forcing %d"),
3231                         depth, (1 << OE_DEPTH_BITS) - 1);
3232                 depth = (1 << OE_DEPTH_BITS) - 1;
3233         }
3234         if (cache_max_small_delta_size >= (1U << OE_Z_DELTA_BITS)) {
3235                 warning(_("pack.deltaCacheLimit is too high, forcing %d"),
3236                         (1U << OE_Z_DELTA_BITS) - 1);
3237                 cache_max_small_delta_size = (1U << OE_Z_DELTA_BITS) - 1;
3238         }
3239
3240         argv_array_push(&rp, "pack-objects");
3241         if (thin) {
3242                 use_internal_rev_list = 1;
3243                 argv_array_push(&rp, shallow
3244                                 ? "--objects-edge-aggressive"
3245                                 : "--objects-edge");
3246         } else
3247                 argv_array_push(&rp, "--objects");
3248
3249         if (rev_list_all) {
3250                 use_internal_rev_list = 1;
3251                 argv_array_push(&rp, "--all");
3252         }
3253         if (rev_list_reflog) {
3254                 use_internal_rev_list = 1;
3255                 argv_array_push(&rp, "--reflog");
3256         }
3257         if (rev_list_index) {
3258                 use_internal_rev_list = 1;
3259                 argv_array_push(&rp, "--indexed-objects");
3260         }
3261         if (rev_list_unpacked) {
3262                 use_internal_rev_list = 1;
3263                 argv_array_push(&rp, "--unpacked");
3264         }
3265
3266         if (exclude_promisor_objects) {
3267                 use_internal_rev_list = 1;
3268                 fetch_if_missing = 0;
3269                 argv_array_push(&rp, "--exclude-promisor-objects");
3270         }
3271         if (unpack_unreachable || keep_unreachable || pack_loose_unreachable)
3272                 use_internal_rev_list = 1;
3273
3274         if (!reuse_object)
3275                 reuse_delta = 0;
3276         if (pack_compression_level == -1)
3277                 pack_compression_level = Z_DEFAULT_COMPRESSION;
3278         else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
3279                 die(_("bad pack compression level %d"), pack_compression_level);
3280
3281         if (!delta_search_threads)      /* --threads=0 means autodetect */
3282                 delta_search_threads = online_cpus();
3283
3284 #ifdef NO_PTHREADS
3285         if (delta_search_threads != 1)
3286                 warning(_("no threads support, ignoring --threads"));
3287 #endif
3288         if (!pack_to_stdout && !pack_size_limit)
3289                 pack_size_limit = pack_size_limit_cfg;
3290         if (pack_to_stdout && pack_size_limit)
3291                 die(_("--max-pack-size cannot be used to build a pack for transfer"));
3292         if (pack_size_limit && pack_size_limit < 1024*1024) {
3293                 warning(_("minimum pack size limit is 1 MiB"));
3294                 pack_size_limit = 1024*1024;
3295         }
3296
3297         if (!pack_to_stdout && thin)
3298                 die(_("--thin cannot be used to build an indexable pack"));
3299
3300         if (keep_unreachable && unpack_unreachable)
3301                 die(_("--keep-unreachable and --unpack-unreachable are incompatible"));
3302         if (!rev_list_all || !rev_list_reflog || !rev_list_index)
3303                 unpack_unreachable_expiration = 0;
3304
3305         if (filter_options.choice) {
3306                 if (!pack_to_stdout)
3307                         die(_("cannot use --filter without --stdout"));
3308                 use_bitmap_index = 0;
3309         }
3310
3311         /*
3312          * "soft" reasons not to use bitmaps - for on-disk repack by default we want
3313          *
3314          * - to produce good pack (with bitmap index not-yet-packed objects are
3315          *   packed in suboptimal order).
3316          *
3317          * - to use more robust pack-generation codepath (avoiding possible
3318          *   bugs in bitmap code and possible bitmap index corruption).
3319          */
3320         if (!pack_to_stdout)
3321                 use_bitmap_index_default = 0;
3322
3323         if (use_bitmap_index < 0)
3324                 use_bitmap_index = use_bitmap_index_default;
3325
3326         /* "hard" reasons not to use bitmaps; these just won't work at all */
3327         if (!use_internal_rev_list || (!pack_to_stdout && write_bitmap_index) || is_repository_shallow(the_repository))
3328                 use_bitmap_index = 0;
3329
3330         if (pack_to_stdout || !rev_list_all)
3331                 write_bitmap_index = 0;
3332
3333         if (progress && all_progress_implied)
3334                 progress = 2;
3335
3336         add_extra_kept_packs(&keep_pack_list);
3337         if (ignore_packed_keep_on_disk) {
3338                 struct packed_git *p;
3339                 for (p = get_packed_git(the_repository); p; p = p->next)
3340                         if (p->pack_local && p->pack_keep)
3341                                 break;
3342                 if (!p) /* no keep-able packs found */
3343                         ignore_packed_keep_on_disk = 0;
3344         }
3345         if (local) {
3346                 /*
3347                  * unlike ignore_packed_keep_on_disk above, we do not
3348                  * want to unset "local" based on looking at packs, as
3349                  * it also covers non-local objects
3350                  */
3351                 struct packed_git *p;
3352                 for (p = get_packed_git(the_repository); p; p = p->next) {
3353                         if (!p->pack_local) {
3354                                 have_non_local_packs = 1;
3355                                 break;
3356                         }
3357                 }
3358         }
3359
3360         prepare_packing_data(&to_pack);
3361
3362         if (progress)
3363                 progress_state = start_progress(_("Enumerating objects"), 0);
3364         if (!use_internal_rev_list)
3365                 read_object_list_from_stdin();
3366         else {
3367                 get_object_list(rp.argc, rp.argv);
3368                 argv_array_clear(&rp);
3369         }
3370         cleanup_preferred_base();
3371         if (include_tag && nr_result)
3372                 for_each_ref(add_ref_tag, NULL);
3373         stop_progress(&progress_state);
3374
3375         if (non_empty && !nr_result)
3376                 return 0;
3377         if (nr_result)
3378                 prepare_pack(window, depth);
3379         write_pack_file();
3380         if (progress)
3381                 fprintf_ln(stderr,
3382                            _("Total %"PRIu32" (delta %"PRIu32"),"
3383                              " reused %"PRIu32" (delta %"PRIu32")"),
3384                            written, written_delta, reused, reused_delta);
3385         return 0;
3386 }