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

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "repository.h"
   4 #include "config.h"
   5 #include "attr.h"
   6 #include "object.h"
   7 #include "blob.h"
   8 #include "commit.h"
   9 #include "tag.h"
  10 #include "tree.h"
  11 #include "delta.h"
  12 #include "pack.h"
  13 #include "pack-revindex.h"
  14 #include "csum-file.h"
  15 #include "tree-walk.h"
  16 #include "diff.h"
  17 #include "revision.h"
  18 #include "list-objects.h"
  19 #include "list-objects-filter.h"
  20 #include "list-objects-filter-options.h"
  21 #include "pack-objects.h"
  22 #include "progress.h"
  23 #include "refs.h"
  24 #include "streaming.h"
  25 #include "thread-utils.h"
  26 #include "pack-bitmap.h"
  27 #include "delta-islands.h"
  28 #include "reachable.h"
  29 #include "sha1-array.h"
  30 #include "argv-array.h"
  31 #include "list.h"
  32 #include "packfile.h"
  33 #include "object-store.h"
  34 #include "dir.h"
  35
  36 #define IN_PACK(obj) oe_in_pack(&to_pack, obj)
  37 #define SIZE(obj) oe_size(&to_pack, obj)
  38 #define SET_SIZE(obj,size) oe_set_size(&to_pack, obj, size)
  39 #define DELTA_SIZE(obj) oe_delta_size(&to_pack, obj)
  40 #define DELTA(obj) oe_delta(&to_pack, obj)
  41 #define DELTA_CHILD(obj) oe_delta_child(&to_pack, obj)
  42 #define DELTA_SIBLING(obj) oe_delta_sibling(&to_pack, obj)
  43 #define SET_DELTA(obj, val) oe_set_delta(&to_pack, obj, val)
  44 #define SET_DELTA_SIZE(obj, val) oe_set_delta_size(&to_pack, obj, val)
  45 #define SET_DELTA_CHILD(obj, val) oe_set_delta_child(&to_pack, obj, val)
  46 #define SET_DELTA_SIBLING(obj, val) oe_set_delta_sibling(&to_pack, obj, val)
  47
  48 static const char *pack_usage[] = {
  49         N_("git pack-objects --stdout [<options>...] [< <ref-list> | < <object-list>]"),
  50         N_("git pack-objects [<options>...] <base-name> [< <ref-list> | < <object-list>]"),
  51         NULL
  52 };
  53
  54 /*
  55  * Objects we are going to pack are collected in the `to_pack` structure.
  56  * It contains an array (dynamically expanded) of the object data, and a map
  57  * that can resolve SHA1s to their position in the array.
  58  */
  59 static struct packing_data to_pack;
  60
  61 static struct pack_idx_entry **written_list;
  62 static uint32_t nr_result, nr_written, nr_seen;
  63 static uint32_t write_layer;
  64
  65 static int non_empty;
  66 static int reuse_delta = 1, reuse_object = 1;
  67 static int keep_unreachable, unpack_unreachable, include_tag;
  68 static timestamp_t unpack_unreachable_expiration;
  69 static int pack_loose_unreachable;
  70 static int local;
  71 static int have_non_local_packs;
  72 static int incremental;
  73 static int ignore_packed_keep_on_disk;
  74 static int ignore_packed_keep_in_core;
  75 static int allow_ofs_delta;
  76 static struct pack_idx_option pack_idx_opts;
  77 static const char *base_name;
  78 static int progress = 1;
  79 static int window = 10;
  80 static unsigned long pack_size_limit;
  81 static int depth = 50;
  82 static int delta_search_threads;
  83 static int pack_to_stdout;
  84 static int num_preferred_base;
  85 static struct progress *progress_state;
  86
  87 static struct packed_git *reuse_packfile;
  88 static uint32_t reuse_packfile_objects;
  89 static off_t reuse_packfile_offset;
  90
  91 static int use_bitmap_index_default = 1;
  92 static int use_bitmap_index = -1;
  93 static int write_bitmap_index;
  94 static uint16_t write_bitmap_options;
  95
  96 static int exclude_promisor_objects;
  97
  98 static int use_delta_islands;
  99
 100 static unsigned long delta_cache_size = 0;
 101 static unsigned long max_delta_cache_size = DEFAULT_DELTA_CACHE_SIZE;
 102 static unsigned long cache_max_small_delta_size = 1000;
 103
 104 static unsigned long window_memory_limit = 0;
 105
 106 static struct list_objects_filter_options filter_options;
 107
 108 enum missing_action {
 109         MA_ERROR = 0,      /* fail if any missing objects are encountered */
 110         MA_ALLOW_ANY,      /* silently allow ALL missing objects */
 111         MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
 112 };
 113 static enum missing_action arg_missing_action;
 114 static show_object_fn fn_show_object;
 115
 116 /*
 117  * stats
 118  */
 119 static uint32_t written, written_delta;
 120 static uint32_t reused, reused_delta;
 121
 122 /*
 123  * Indexed commits
 124  */
 125 static struct commit **indexed_commits;
 126 static unsigned int indexed_commits_nr;
 127 static unsigned int indexed_commits_alloc;
 128
 129 static void index_commit_for_bitmap(struct commit *commit)
 130 {
 131         if (indexed_commits_nr >= indexed_commits_alloc) {
 132                 indexed_commits_alloc = (indexed_commits_alloc + 32) * 2;
 133                 REALLOC_ARRAY(indexed_commits, indexed_commits_alloc);
 134         }
 135
 136         indexed_commits[indexed_commits_nr++] = commit;
 137 }
 138
 139 static void *get_delta(struct object_entry *entry)
 140 {
 141         unsigned long size, base_size, delta_size;
 142         void *buf, *base_buf, *delta_buf;
 143         enum object_type type;
 144
 145         buf = read_object_file(&entry->idx.oid, &type, &size);
 146         if (!buf)
 147                 die("unable to read %s", oid_to_hex(&entry->idx.oid));
 148         base_buf = read_object_file(&DELTA(entry)->idx.oid, &type,
 149                                     &base_size);
 150         if (!base_buf)
 151                 die("unable to read %s",
 152                     oid_to_hex(&DELTA(entry)->idx.oid));
 153         delta_buf = diff_delta(base_buf, base_size,
 154                                buf, size, &delta_size, 0);
 155         if (!delta_buf || delta_size != DELTA_SIZE(entry))
 156                 die("delta size changed");
 157         free(buf);
 158         free(base_buf);
 159         return delta_buf;
 160 }
 161
 162 static unsigned long do_compress(void **pptr, unsigned long size)
 163 {
 164         git_zstream stream;
 165         void *in, *out;
 166         unsigned long maxsize;
 167
 168         git_deflate_init(&stream, pack_compression_level);
 169         maxsize = git_deflate_bound(&stream, size);
 170
 171         in = *pptr;
 172         out = xmalloc(maxsize);
 173         *pptr = out;
 174
 175         stream.next_in = in;
 176         stream.avail_in = size;
 177         stream.next_out = out;
 178         stream.avail_out = maxsize;
 179         while (git_deflate(&stream, Z_FINISH) == Z_OK)
 180                 ; /* nothing */
 181         git_deflate_end(&stream);
 182
 183         free(in);
 184         return stream.total_out;
 185 }
 186
 187 static unsigned long write_large_blob_data(struct git_istream *st, struct hashfile *f,
 188                                            const struct object_id *oid)
 189 {
 190         git_zstream stream;
 191         unsigned char ibuf[1024 * 16];
 192         unsigned char obuf[1024 * 16];
 193         unsigned long olen = 0;
 194
 195         git_deflate_init(&stream, pack_compression_level);
 196
 197         for (;;) {
 198                 ssize_t readlen;
 199                 int zret = Z_OK;
 200                 readlen = read_istream(st, ibuf, sizeof(ibuf));
 201                 if (readlen == -1)
 202                         die(_("unable to read %s"), oid_to_hex(oid));
 203
 204                 stream.next_in = ibuf;
 205                 stream.avail_in = readlen;
 206                 while ((stream.avail_in || readlen == 0) &&
 207                        (zret == Z_OK || zret == Z_BUF_ERROR)) {
 208                         stream.next_out = obuf;
 209                         stream.avail_out = sizeof(obuf);
 210                         zret = git_deflate(&stream, readlen ? 0 : Z_FINISH);
 211                         hashwrite(f, obuf, stream.next_out - obuf);
 212                         olen += stream.next_out - obuf;
 213                 }
 214                 if (stream.avail_in)
 215                         die(_("deflate error (%d)"), zret);
 216                 if (readlen == 0) {
 217                         if (zret != Z_STREAM_END)
 218                                 die(_("deflate error (%d)"), zret);
 219                         break;
 220                 }
 221         }
 222         git_deflate_end(&stream);
 223         return olen;
 224 }
 225
 226 /*
 227  * we are going to reuse the existing object data as is.  make
 228  * sure it is not corrupt.
 229  */
 230 static int check_pack_inflate(struct packed_git *p,
 231                 struct pack_window **w_curs,
 232                 off_t offset,
 233                 off_t len,
 234                 unsigned long expect)
 235 {
 236         git_zstream stream;
 237         unsigned char fakebuf[4096], *in;
 238         int st;
 239
 240         memset(&stream, 0, sizeof(stream));
 241         git_inflate_init(&stream);
 242         do {
 243                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 244                 stream.next_in = in;
 245                 stream.next_out = fakebuf;
 246                 stream.avail_out = sizeof(fakebuf);
 247                 st = git_inflate(&stream, Z_FINISH);
 248                 offset += stream.next_in - in;
 249         } while (st == Z_OK || st == Z_BUF_ERROR);
 250         git_inflate_end(&stream);
 251         return (st == Z_STREAM_END &&
 252                 stream.total_out == expect &&
 253                 stream.total_in == len) ? 0 : -1;
 254 }
 255
 256 static void copy_pack_data(struct hashfile *f,
 257                 struct packed_git *p,
 258                 struct pack_window **w_curs,
 259                 off_t offset,
 260                 off_t len)
 261 {
 262         unsigned char *in;
 263         unsigned long avail;
 264
 265         while (len) {
 266                 in = use_pack(p, w_curs, offset, &avail);
 267                 if (avail > len)
 268                         avail = (unsigned long)len;
 269                 hashwrite(f, in, avail);
 270                 offset += avail;
 271                 len -= avail;
 272         }
 273 }
 274
 275 /* Return 0 if we will bust the pack-size limit */
 276 static unsigned long write_no_reuse_object(struct hashfile *f, struct object_entry *entry,
 277                                            unsigned long limit, int usable_delta)
 278 {
 279         unsigned long size, datalen;
 280         unsigned char header[MAX_PACK_OBJECT_HEADER],
 281                       dheader[MAX_PACK_OBJECT_HEADER];
 282         unsigned hdrlen;
 283         enum object_type type;
 284         void *buf;
 285         struct git_istream *st = NULL;
 286         const unsigned hashsz = the_hash_algo->rawsz;
 287
 288         if (!usable_delta) {
 289                 if (oe_type(entry) == OBJ_BLOB &&
 290                     oe_size_greater_than(&to_pack, entry, big_file_threshold) &&
 291                     (st = open_istream(&entry->idx.oid, &type, &size, NULL)) != NULL)
 292                         buf = NULL;
 293                 else {
 294                         buf = read_object_file(&entry->idx.oid, &type, &size);
 295                         if (!buf)
 296                                 die(_("unable to read %s"),
 297                                     oid_to_hex(&entry->idx.oid));
 298                 }
 299                 /*
 300                  * make sure no cached delta data remains from a
 301                  * previous attempt before a pack split occurred.
 302                  */
 303                 FREE_AND_NULL(entry->delta_data);
 304                 entry->z_delta_size = 0;
 305         } else if (entry->delta_data) {
 306                 size = DELTA_SIZE(entry);
 307                 buf = entry->delta_data;
 308                 entry->delta_data = NULL;
 309                 type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 310                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 311         } else {
 312                 buf = get_delta(entry);
 313                 size = DELTA_SIZE(entry);
 314                 type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 315                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 316         }
 317
 318         if (st) /* large blob case, just assume we don't compress well */
 319                 datalen = size;
 320         else if (entry->z_delta_size)
 321                 datalen = entry->z_delta_size;
 322         else
 323                 datalen = do_compress(&buf, size);
 324
 325         /*
 326          * The object header is a byte of 'type' followed by zero or
 327          * more bytes of length.
 328          */
 329         hdrlen = encode_in_pack_object_header(header, sizeof(header),
 330                                               type, size);
 331
 332         if (type == OBJ_OFS_DELTA) {
 333                 /*
 334                  * Deltas with relative base contain an additional
 335                  * encoding of the relative offset for the delta
 336                  * base from this object's position in the pack.
 337                  */
 338                 off_t ofs = entry->idx.offset - DELTA(entry)->idx.offset;
 339                 unsigned pos = sizeof(dheader) - 1;
 340                 dheader[pos] = ofs & 127;
 341                 while (ofs >>= 7)
 342                         dheader[--pos] = 128 | (--ofs & 127);
 343                 if (limit && hdrlen + sizeof(dheader) - pos + datalen + hashsz >= limit) {
 344                         if (st)
 345                                 close_istream(st);
 346                         free(buf);
 347                         return 0;
 348                 }
 349                 hashwrite(f, header, hdrlen);
 350                 hashwrite(f, dheader + pos, sizeof(dheader) - pos);
 351                 hdrlen += sizeof(dheader) - pos;
 352         } else if (type == OBJ_REF_DELTA) {
 353                 /*
 354                  * Deltas with a base reference contain
 355                  * additional bytes for the base object ID.
 356                  */
 357                 if (limit && hdrlen + hashsz + datalen + hashsz >= limit) {
 358                         if (st)
 359                                 close_istream(st);
 360                         free(buf);
 361                         return 0;
 362                 }
 363                 hashwrite(f, header, hdrlen);
 364                 hashwrite(f, DELTA(entry)->idx.oid.hash, hashsz);
 365                 hdrlen += hashsz;
 366         } else {
 367                 if (limit && hdrlen + datalen + hashsz >= limit) {
 368                         if (st)
 369                                 close_istream(st);
 370                         free(buf);
 371                         return 0;
 372                 }
 373                 hashwrite(f, header, hdrlen);
 374         }
 375         if (st) {
 376                 datalen = write_large_blob_data(st, f, &entry->idx.oid);
 377                 close_istream(st);
 378         } else {
 379                 hashwrite(f, buf, datalen);
 380                 free(buf);
 381         }
 382
 383         return hdrlen + datalen;
 384 }
 385
 386 /* Return 0 if we will bust the pack-size limit */
 387 static off_t write_reuse_object(struct hashfile *f, struct object_entry *entry,
 388                                 unsigned long limit, int usable_delta)
 389 {
 390         struct packed_git *p = IN_PACK(entry);
 391         struct pack_window *w_curs = NULL;
 392         struct revindex_entry *revidx;
 393         off_t offset;
 394         enum object_type type = oe_type(entry);
 395         off_t datalen;
 396         unsigned char header[MAX_PACK_OBJECT_HEADER],
 397                       dheader[MAX_PACK_OBJECT_HEADER];
 398         unsigned hdrlen;
 399         const unsigned hashsz = the_hash_algo->rawsz;
 400         unsigned long entry_size = SIZE(entry);
 401
 402         if (DELTA(entry))
 403                 type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 404                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 405         hdrlen = encode_in_pack_object_header(header, sizeof(header),
 406                                               type, entry_size);
 407
 408         offset = entry->in_pack_offset;
 409         revidx = find_pack_revindex(p, offset);
 410         datalen = revidx[1].offset - offset;
 411         if (!pack_to_stdout && p->index_version > 1 &&
 412             check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 413                 error("bad packed object CRC for %s",
 414                       oid_to_hex(&entry->idx.oid));
 415                 unuse_pack(&w_curs);
 416                 return write_no_reuse_object(f, entry, limit, usable_delta);
 417         }
 418
 419         offset += entry->in_pack_header_size;
 420         datalen -= entry->in_pack_header_size;
 421
 422         if (!pack_to_stdout && p->index_version == 1 &&
 423             check_pack_inflate(p, &w_curs, offset, datalen, entry_size)) {
 424                 error("corrupt packed object for %s",
 425                       oid_to_hex(&entry->idx.oid));
 426                 unuse_pack(&w_curs);
 427                 return write_no_reuse_object(f, entry, limit, usable_delta);
 428         }
 429
 430         if (type == OBJ_OFS_DELTA) {
 431                 off_t ofs = entry->idx.offset - DELTA(entry)->idx.offset;
 432                 unsigned pos = sizeof(dheader) - 1;
 433                 dheader[pos] = ofs & 127;
 434                 while (ofs >>= 7)
 435                         dheader[--pos] = 128 | (--ofs & 127);
 436                 if (limit && hdrlen + sizeof(dheader) - pos + datalen + hashsz >= limit) {
 437                         unuse_pack(&w_curs);
 438                         return 0;
 439                 }
 440                 hashwrite(f, header, hdrlen);
 441                 hashwrite(f, dheader + pos, sizeof(dheader) - pos);
 442                 hdrlen += sizeof(dheader) - pos;
 443                 reused_delta++;
 444         } else if (type == OBJ_REF_DELTA) {
 445                 if (limit && hdrlen + hashsz + datalen + hashsz >= limit) {
 446                         unuse_pack(&w_curs);
 447                         return 0;
 448                 }
 449                 hashwrite(f, header, hdrlen);
 450                 hashwrite(f, DELTA(entry)->idx.oid.hash, hashsz);
 451                 hdrlen += hashsz;
 452                 reused_delta++;
 453         } else {
 454                 if (limit && hdrlen + datalen + hashsz >= limit) {
 455                         unuse_pack(&w_curs);
 456                         return 0;
 457                 }
 458                 hashwrite(f, header, hdrlen);
 459         }
 460         copy_pack_data(f, p, &w_curs, offset, datalen);
 461         unuse_pack(&w_curs);
 462         reused++;
 463         return hdrlen + datalen;
 464 }
 465
 466 /* Return 0 if we will bust the pack-size limit */
 467 static off_t write_object(struct hashfile *f,
 468                           struct object_entry *entry,
 469                           off_t write_offset)
 470 {
 471         unsigned long limit;
 472         off_t len;
 473         int usable_delta, to_reuse;
 474
 475         if (!pack_to_stdout)
 476                 crc32_begin(f);
 477
 478         /* apply size limit if limited packsize and not first object */
 479         if (!pack_size_limit || !nr_written)
 480                 limit = 0;
 481         else if (pack_size_limit <= write_offset)
 482                 /*
 483                  * the earlier object did not fit the limit; avoid
 484                  * mistaking this with unlimited (i.e. limit = 0).
 485                  */
 486                 limit = 1;
 487         else
 488                 limit = pack_size_limit - write_offset;
 489
 490         if (!DELTA(entry))
 491                 usable_delta = 0;       /* no delta */
 492         else if (!pack_size_limit)
 493                usable_delta = 1;        /* unlimited packfile */
 494         else if (DELTA(entry)->idx.offset == (off_t)-1)
 495                 usable_delta = 0;       /* base was written to another pack */
 496         else if (DELTA(entry)->idx.offset)
 497                 usable_delta = 1;       /* base already exists in this pack */
 498         else
 499                 usable_delta = 0;       /* base could end up in another pack */
 500
 501         if (!reuse_object)
 502                 to_reuse = 0;   /* explicit */
 503         else if (!IN_PACK(entry))
 504                 to_reuse = 0;   /* can't reuse what we don't have */
 505         else if (oe_type(entry) == OBJ_REF_DELTA ||
 506                  oe_type(entry) == OBJ_OFS_DELTA)
 507                                 /* check_object() decided it for us ... */
 508                 to_reuse = usable_delta;
 509                                 /* ... but pack split may override that */
 510         else if (oe_type(entry) != entry->in_pack_type)
 511                 to_reuse = 0;   /* pack has delta which is unusable */
 512         else if (DELTA(entry))
 513                 to_reuse = 0;   /* we want to pack afresh */
 514         else
 515                 to_reuse = 1;   /* we have it in-pack undeltified,
 516                                  * and we do not need to deltify it.
 517                                  */
 518
 519         if (!to_reuse)
 520                 len = write_no_reuse_object(f, entry, limit, usable_delta);
 521         else
 522                 len = write_reuse_object(f, entry, limit, usable_delta);
 523         if (!len)
 524                 return 0;
 525
 526         if (usable_delta)
 527                 written_delta++;
 528         written++;
 529         if (!pack_to_stdout)
 530                 entry->idx.crc32 = crc32_end(f);
 531         return len;
 532 }
 533
 534 enum write_one_status {
 535         WRITE_ONE_SKIP = -1, /* already written */
 536         WRITE_ONE_BREAK = 0, /* writing this will bust the limit; not written */
 537         WRITE_ONE_WRITTEN = 1, /* normal */
 538         WRITE_ONE_RECURSIVE = 2 /* already scheduled to be written */
 539 };
 540
 541 static enum write_one_status write_one(struct hashfile *f,
 542                                        struct object_entry *e,
 543                                        off_t *offset)
 544 {
 545         off_t size;
 546         int recursing;
 547
 548         /*
 549          * we set offset to 1 (which is an impossible value) to mark
 550          * the fact that this object is involved in "write its base
 551          * first before writing a deltified object" recursion.
 552          */
 553         recursing = (e->idx.offset == 1);
 554         if (recursing) {
 555                 warning("recursive delta detected for object %s",
 556                         oid_to_hex(&e->idx.oid));
 557                 return WRITE_ONE_RECURSIVE;
 558         } else if (e->idx.offset || e->preferred_base) {
 559                 /* offset is non zero if object is written already. */
 560                 return WRITE_ONE_SKIP;
 561         }
 562
 563         /* if we are deltified, write out base object first. */
 564         if (DELTA(e)) {
 565                 e->idx.offset = 1; /* now recurse */
 566                 switch (write_one(f, DELTA(e), offset)) {
 567                 case WRITE_ONE_RECURSIVE:
 568                         /* we cannot depend on this one */
 569                         SET_DELTA(e, NULL);
 570                         break;
 571                 default:
 572                         break;
 573                 case WRITE_ONE_BREAK:
 574                         e->idx.offset = recursing;
 575                         return WRITE_ONE_BREAK;
 576                 }
 577         }
 578
 579         e->idx.offset = *offset;
 580         size = write_object(f, e, *offset);
 581         if (!size) {
 582                 e->idx.offset = recursing;
 583                 return WRITE_ONE_BREAK;
 584         }
 585         written_list[nr_written++] = &e->idx;
 586
 587         /* make sure off_t is sufficiently large not to wrap */
 588         if (signed_add_overflows(*offset, size))
 589                 die("pack too large for current definition of off_t");
 590         *offset += size;
 591         return WRITE_ONE_WRITTEN;
 592 }
 593
 594 static int mark_tagged(const char *path, const struct object_id *oid, int flag,
 595                        void *cb_data)
 596 {
 597         struct object_id peeled;
 598         struct object_entry *entry = packlist_find(&to_pack, oid->hash, NULL);
 599
 600         if (entry)
 601                 entry->tagged = 1;
 602         if (!peel_ref(path, &peeled)) {
 603                 entry = packlist_find(&to_pack, peeled.hash, NULL);
 604                 if (entry)
 605                         entry->tagged = 1;
 606         }
 607         return 0;
 608 }
 609
 610 static inline void add_to_write_order(struct object_entry **wo,
 611                                unsigned int *endp,
 612                                struct object_entry *e)
 613 {
 614         if (e->filled || e->layer != write_layer)
 615                 return;
 616         wo[(*endp)++] = e;
 617         e->filled = 1;
 618 }
 619
 620 static void add_descendants_to_write_order(struct object_entry **wo,
 621                                            unsigned int *endp,
 622                                            struct object_entry *e)
 623 {
 624         int add_to_order = 1;
 625         while (e) {
 626                 if (add_to_order) {
 627                         struct object_entry *s;
 628                         /* add this node... */
 629                         add_to_write_order(wo, endp, e);
 630                         /* all its siblings... */
 631                         for (s = DELTA_SIBLING(e); s; s = DELTA_SIBLING(s)) {
 632                                 add_to_write_order(wo, endp, s);
 633                         }
 634                 }
 635                 /* drop down a level to add left subtree nodes if possible */
 636                 if (DELTA_CHILD(e)) {
 637                         add_to_order = 1;
 638                         e = DELTA_CHILD(e);
 639                 } else {
 640                         add_to_order = 0;
 641                         /* our sibling might have some children, it is next */
 642                         if (DELTA_SIBLING(e)) {
 643                                 e = DELTA_SIBLING(e);
 644                                 continue;
 645                         }
 646                         /* go back to our parent node */
 647                         e = DELTA(e);
 648                         while (e && !DELTA_SIBLING(e)) {
 649                                 /* we're on the right side of a subtree, keep
 650                                  * going up until we can go right again */
 651                                 e = DELTA(e);
 652                         }
 653                         if (!e) {
 654                                 /* done- we hit our original root node */
 655                                 return;
 656                         }
 657                         /* pass it off to sibling at this level */
 658                         e = DELTA_SIBLING(e);
 659                 }
 660         };
 661 }
 662
 663 static void add_family_to_write_order(struct object_entry **wo,
 664                                       unsigned int *endp,
 665                                       struct object_entry *e)
 666 {
 667         struct object_entry *root;
 668
 669         for (root = e; DELTA(root); root = DELTA(root))
 670                 ; /* nothing */
 671         add_descendants_to_write_order(wo, endp, root);
 672 }
 673
 674 static void compute_layer_order(struct object_entry **wo, unsigned int *wo_end)
 675 {
 676         unsigned int i, last_untagged;
 677         struct object_entry *objects = to_pack.objects;
 678
 679         for (i = 0; i < to_pack.nr_objects; i++) {
 680                 if (objects[i].tagged)
 681                         break;
 682                 add_to_write_order(wo, wo_end, &objects[i]);
 683         }
 684         last_untagged = i;
 685
 686         /*
 687          * Then fill all the tagged tips.
 688          */
 689         for (; i < to_pack.nr_objects; i++) {
 690                 if (objects[i].tagged)
 691                         add_to_write_order(wo, wo_end, &objects[i]);
 692         }
 693
 694         /*
 695          * And then all remaining commits and tags.
 696          */
 697         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 698                 if (oe_type(&objects[i]) != OBJ_COMMIT &&
 699                     oe_type(&objects[i]) != OBJ_TAG)
 700                         continue;
 701                 add_to_write_order(wo, wo_end, &objects[i]);
 702         }
 703
 704         /*
 705          * And then all the trees.
 706          */
 707         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 708                 if (oe_type(&objects[i]) != OBJ_TREE)
 709                         continue;
 710                 add_to_write_order(wo, wo_end, &objects[i]);
 711         }
 712
 713         /*
 714          * Finally all the rest in really tight order
 715          */
 716         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 717                 if (!objects[i].filled && objects[i].layer == write_layer)
 718                         add_family_to_write_order(wo, wo_end, &objects[i]);
 719         }
 720 }
 721
 722 static struct object_entry **compute_write_order(void)
 723 {
 724         uint32_t max_layers = 1;
 725         unsigned int i, wo_end;
 726
 727         struct object_entry **wo;
 728         struct object_entry *objects = to_pack.objects;
 729
 730         for (i = 0; i < to_pack.nr_objects; i++) {
 731                 objects[i].tagged = 0;
 732                 objects[i].filled = 0;
 733                 SET_DELTA_CHILD(&objects[i], NULL);
 734                 SET_DELTA_SIBLING(&objects[i], NULL);
 735         }
 736
 737         /*
 738          * Fully connect delta_child/delta_sibling network.
 739          * Make sure delta_sibling is sorted in the original
 740          * recency order.
 741          */
 742         for (i = to_pack.nr_objects; i > 0;) {
 743                 struct object_entry *e = &objects[--i];
 744                 if (!DELTA(e))
 745                         continue;
 746                 /* Mark me as the first child */
 747                 e->delta_sibling_idx = DELTA(e)->delta_child_idx;
 748                 SET_DELTA_CHILD(DELTA(e), e);
 749         }
 750
 751         /*
 752          * Mark objects that are at the tip of tags.
 753          */
 754         for_each_tag_ref(mark_tagged, NULL);
 755
 756         if (use_delta_islands)
 757                 max_layers = compute_pack_layers(&to_pack);
 758
 759         ALLOC_ARRAY(wo, to_pack.nr_objects);
 760         wo_end = 0;
 761
 762         for (; write_layer < max_layers; ++write_layer)
 763                 compute_layer_order(wo, &wo_end);
 764
 765         if (wo_end != to_pack.nr_objects)
 766                 die("ordered %u objects, expected %"PRIu32, wo_end, to_pack.nr_objects);
 767
 768         return wo;
 769 }
 770
 771 static off_t write_reused_pack(struct hashfile *f)
 772 {
 773         unsigned char buffer[8192];
 774         off_t to_write, total;
 775         int fd;
 776
 777         if (!is_pack_valid(reuse_packfile))
 778                 die("packfile is invalid: %s", reuse_packfile->pack_name);
 779
 780         fd = git_open(reuse_packfile->pack_name);
 781         if (fd < 0)
 782                 die_errno("unable to open packfile for reuse: %s",
 783                           reuse_packfile->pack_name);
 784
 785         if (lseek(fd, sizeof(struct pack_header), SEEK_SET) == -1)
 786                 die_errno("unable to seek in reused packfile");
 787
 788         if (reuse_packfile_offset < 0)
 789                 reuse_packfile_offset = reuse_packfile->pack_size - the_hash_algo->rawsz;
 790
 791         total = to_write = reuse_packfile_offset - sizeof(struct pack_header);
 792
 793         while (to_write) {
 794                 int read_pack = xread(fd, buffer, sizeof(buffer));
 795
 796                 if (read_pack <= 0)
 797                         die_errno("unable to read from reused packfile");
 798
 799                 if (read_pack > to_write)
 800                         read_pack = to_write;
 801
 802                 hashwrite(f, buffer, read_pack);
 803                 to_write -= read_pack;
 804
 805                 /*
 806                  * We don't know the actual number of objects written,
 807                  * only how many bytes written, how many bytes total, and
 808                  * how many objects total. So we can fake it by pretending all
 809                  * objects we are writing are the same size. This gives us a
 810                  * smooth progress meter, and at the end it matches the true
 811                  * answer.
 812                  */
 813                 written = reuse_packfile_objects *
 814                                 (((double)(total - to_write)) / total);
 815                 display_progress(progress_state, written);
 816         }
 817
 818         close(fd);
 819         written = reuse_packfile_objects;
 820         display_progress(progress_state, written);
 821         return reuse_packfile_offset - sizeof(struct pack_header);
 822 }
 823
 824 static const char no_split_warning[] = N_(
 825 "disabling bitmap writing, packs are split due to pack.packSizeLimit"
 826 );
 827
 828 static void write_pack_file(void)
 829 {
 830         uint32_t i = 0, j;
 831         struct hashfile *f;
 832         off_t offset;
 833         uint32_t nr_remaining = nr_result;
 834         time_t last_mtime = 0;
 835         struct object_entry **write_order;
 836
 837         if (progress > pack_to_stdout)
 838                 progress_state = start_progress(_("Writing objects"), nr_result);
 839         ALLOC_ARRAY(written_list, to_pack.nr_objects);
 840         write_order = compute_write_order();
 841
 842         do {
 843                 struct object_id oid;
 844                 char *pack_tmp_name = NULL;
 845
 846                 if (pack_to_stdout)
 847                         f = hashfd_throughput(1, "<stdout>", progress_state);
 848                 else
 849                         f = create_tmp_packfile(&pack_tmp_name);
 850
 851                 offset = write_pack_header(f, nr_remaining);
 852
 853                 if (reuse_packfile) {
 854                         off_t packfile_size;
 855                         assert(pack_to_stdout);
 856
 857                         packfile_size = write_reused_pack(f);
 858                         offset += packfile_size;
 859                 }
 860
 861                 nr_written = 0;
 862                 for (; i < to_pack.nr_objects; i++) {
 863                         struct object_entry *e = write_order[i];
 864                         if (write_one(f, e, &offset) == WRITE_ONE_BREAK)
 865                                 break;
 866                         display_progress(progress_state, written);
 867                 }
 868
 869                 /*
 870                  * Did we write the wrong # entries in the header?
 871                  * If so, rewrite it like in fast-import
 872                  */
 873                 if (pack_to_stdout) {
 874                         finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_CLOSE);
 875                 } else if (nr_written == nr_remaining) {
 876                         finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
 877                 } else {
 878                         int fd = finalize_hashfile(f, oid.hash, 0);
 879                         fixup_pack_header_footer(fd, oid.hash, pack_tmp_name,
 880                                                  nr_written, oid.hash, offset);
 881                         close(fd);
 882                         if (write_bitmap_index) {
 883                                 warning(_(no_split_warning));
 884                                 write_bitmap_index = 0;
 885                         }
 886                 }
 887
 888                 if (!pack_to_stdout) {
 889                         struct stat st;
 890                         struct strbuf tmpname = STRBUF_INIT;
 891
 892                         /*
 893                          * Packs are runtime accessed in their mtime
 894                          * order since newer packs are more likely to contain
 895                          * younger objects.  So if we are creating multiple
 896                          * packs then we should modify the mtime of later ones
 897                          * to preserve this property.
 898                          */
 899                         if (stat(pack_tmp_name, &st) < 0) {
 900                                 warning_errno("failed to stat %s", pack_tmp_name);
 901                         } else if (!last_mtime) {
 902                                 last_mtime = st.st_mtime;
 903                         } else {
 904                                 struct utimbuf utb;
 905                                 utb.actime = st.st_atime;
 906                                 utb.modtime = --last_mtime;
 907                                 if (utime(pack_tmp_name, &utb) < 0)
 908                                         warning_errno("failed utime() on %s", pack_tmp_name);
 909                         }
 910
 911                         strbuf_addf(&tmpname, "%s-", base_name);
 912
 913                         if (write_bitmap_index) {
 914                                 bitmap_writer_set_checksum(oid.hash);
 915                                 bitmap_writer_build_type_index(
 916                                         &to_pack, written_list, nr_written);
 917                         }
 918
 919                         finish_tmp_packfile(&tmpname, pack_tmp_name,
 920                                             written_list, nr_written,
 921                                             &pack_idx_opts, oid.hash);
 922
 923                         if (write_bitmap_index) {
 924                                 strbuf_addf(&tmpname, "%s.bitmap", oid_to_hex(&oid));
 925
 926                                 stop_progress(&progress_state);
 927
 928                                 bitmap_writer_show_progress(progress);
 929                                 bitmap_writer_reuse_bitmaps(&to_pack);
 930                                 bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
 931                                 bitmap_writer_build(&to_pack);
 932                                 bitmap_writer_finish(written_list, nr_written,
 933                                                      tmpname.buf, write_bitmap_options);
 934                                 write_bitmap_index = 0;
 935                         }
 936
 937                         strbuf_release(&tmpname);
 938                         free(pack_tmp_name);
 939                         puts(oid_to_hex(&oid));
 940                 }
 941
 942                 /* mark written objects as written to previous pack */
 943                 for (j = 0; j < nr_written; j++) {
 944                         written_list[j]->offset = (off_t)-1;
 945                 }
 946                 nr_remaining -= nr_written;
 947         } while (nr_remaining && i < to_pack.nr_objects);
 948
 949         free(written_list);
 950         free(write_order);
 951         stop_progress(&progress_state);
 952         if (written != nr_result)
 953                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
 954                         written, nr_result);
 955 }
 956
 957 static int no_try_delta(const char *path)
 958 {
 959         static struct attr_check *check;
 960
 961         if (!check)
 962                 check = attr_check_initl("delta", NULL);
 963         if (git_check_attr(path, check))
 964                 return 0;
 965         if (ATTR_FALSE(check->items[0].value))
 966                 return 1;
 967         return 0;
 968 }
 969
 970 /*
 971  * When adding an object, check whether we have already added it
 972  * to our packing list. If so, we can skip. However, if we are
 973  * being asked to excludei t, but the previous mention was to include
 974  * it, make sure to adjust its flags and tweak our numbers accordingly.
 975  *
 976  * As an optimization, we pass out the index position where we would have
 977  * found the item, since that saves us from having to look it up again a
 978  * few lines later when we want to add the new entry.
 979  */
 980 static int have_duplicate_entry(const struct object_id *oid,
 981                                 int exclude,
 982                                 uint32_t *index_pos)
 983 {
 984         struct object_entry *entry;
 985
 986         entry = packlist_find(&to_pack, oid->hash, index_pos);
 987         if (!entry)
 988                 return 0;
 989
 990         if (exclude) {
 991                 if (!entry->preferred_base)
 992                         nr_result--;
 993                 entry->preferred_base = 1;
 994         }
 995
 996         return 1;
 997 }
 998
 999 static int want_found_object(int exclude, struct packed_git *p)
1000 {
1001         if (exclude)
1002                 return 1;
1003         if (incremental)
1004                 return 0;
1005
1006         /*
1007          * When asked to do --local (do not include an object that appears in a
1008          * pack we borrow from elsewhere) or --honor-pack-keep (do not include
1009          * an object that appears in a pack marked with .keep), finding a pack
1010          * that matches the criteria is sufficient for us to decide to omit it.
1011          * However, even if this pack does not satisfy the criteria, we need to
1012          * make sure no copy of this object appears in _any_ pack that makes us
1013          * to omit the object, so we need to check all the packs.
1014          *
1015          * We can however first check whether these options can possible matter;
1016          * if they do not matter we know we want the object in generated pack.
1017          * Otherwise, we signal "-1" at the end to tell the caller that we do
1018          * not know either way, and it needs to check more packs.
1019          */
1020         if (!ignore_packed_keep_on_disk &&
1021             !ignore_packed_keep_in_core &&
1022             (!local || !have_non_local_packs))
1023                 return 1;
1024
1025         if (local && !p->pack_local)
1026                 return 0;
1027         if (p->pack_local &&
1028             ((ignore_packed_keep_on_disk && p->pack_keep) ||
1029              (ignore_packed_keep_in_core && p->pack_keep_in_core)))
1030                 return 0;
1031
1032         /* we don't know yet; keep looking for more packs */
1033         return -1;
1034 }
1035
1036 /*
1037  * Check whether we want the object in the pack (e.g., we do not want
1038  * objects found in non-local stores if the "--local" option was used).
1039  *
1040  * If the caller already knows an existing pack it wants to take the object
1041  * from, that is passed in *found_pack and *found_offset; otherwise this
1042  * function finds if there is any pack that has the object and returns the pack
1043  * and its offset in these variables.
1044  */
1045 static int want_object_in_pack(const struct object_id *oid,
1046                                int exclude,
1047                                struct packed_git **found_pack,
1048                                off_t *found_offset)
1049 {
1050         int want;
1051         struct list_head *pos;
1052
1053         if (!exclude && local && has_loose_object_nonlocal(oid))
1054                 return 0;
1055
1056         /*
1057          * If we already know the pack object lives in, start checks from that
1058          * pack - in the usual case when neither --local was given nor .keep files
1059          * are present we will determine the answer right now.
1060          */
1061         if (*found_pack) {
1062                 want = want_found_object(exclude, *found_pack);
1063                 if (want != -1)
1064                         return want;
1065         }
1066         list_for_each(pos, get_packed_git_mru(the_repository)) {
1067                 struct packed_git *p = list_entry(pos, struct packed_git, mru);
1068                 off_t offset;
1069
1070                 if (p == *found_pack)
1071                         offset = *found_offset;
1072                 else
1073                         offset = find_pack_entry_one(oid->hash, p);
1074
1075                 if (offset) {
1076                         if (!*found_pack) {
1077                                 if (!is_pack_valid(p))
1078                                         continue;
1079                                 *found_offset = offset;
1080                                 *found_pack = p;
1081                         }
1082                         want = want_found_object(exclude, p);
1083                         if (!exclude && want > 0)
1084                                 list_move(&p->mru,
1085                                           get_packed_git_mru(the_repository));
1086                         if (want != -1)
1087                                 return want;
1088                 }
1089         }
1090
1091         return 1;
1092 }
1093
1094 static void create_object_entry(const struct object_id *oid,
1095                                 enum object_type type,
1096                                 uint32_t hash,
1097                                 int exclude,
1098                                 int no_try_delta,
1099                                 uint32_t index_pos,
1100                                 struct packed_git *found_pack,
1101                                 off_t found_offset)
1102 {
1103         struct object_entry *entry;
1104
1105         entry = packlist_alloc(&to_pack, oid->hash, index_pos);
1106         entry->hash = hash;
1107         oe_set_type(entry, type);
1108         if (exclude)
1109                 entry->preferred_base = 1;
1110         else
1111                 nr_result++;
1112         if (found_pack) {
1113                 oe_set_in_pack(&to_pack, entry, found_pack);
1114                 entry->in_pack_offset = found_offset;
1115         }
1116
1117         entry->no_try_delta = no_try_delta;
1118 }
1119
1120 static const char no_closure_warning[] = N_(
1121 "disabling bitmap writing, as some objects are not being packed"
1122 );
1123
1124 static int add_object_entry(const struct object_id *oid, enum object_type type,
1125                             const char *name, int exclude)
1126 {
1127         struct packed_git *found_pack = NULL;
1128         off_t found_offset = 0;
1129         uint32_t index_pos;
1130
1131         display_progress(progress_state, ++nr_seen);
1132
1133         if (have_duplicate_entry(oid, exclude, &index_pos))
1134                 return 0;
1135
1136         if (!want_object_in_pack(oid, exclude, &found_pack, &found_offset)) {
1137                 /* The pack is missing an object, so it will not have closure */
1138                 if (write_bitmap_index) {
1139                         warning(_(no_closure_warning));
1140                         write_bitmap_index = 0;
1141                 }
1142                 return 0;
1143         }
1144
1145         create_object_entry(oid, type, pack_name_hash(name),
1146                             exclude, name && no_try_delta(name),
1147                             index_pos, found_pack, found_offset);
1148         return 1;
1149 }
1150
1151 static int add_object_entry_from_bitmap(const struct object_id *oid,
1152                                         enum object_type type,
1153                                         int flags, uint32_t name_hash,
1154                                         struct packed_git *pack, off_t offset)
1155 {
1156         uint32_t index_pos;
1157
1158         display_progress(progress_state, ++nr_seen);
1159
1160         if (have_duplicate_entry(oid, 0, &index_pos))
1161                 return 0;
1162
1163         if (!want_object_in_pack(oid, 0, &pack, &offset))
1164                 return 0;
1165
1166         create_object_entry(oid, type, name_hash, 0, 0, index_pos, pack, offset);
1167         return 1;
1168 }
1169
1170 struct pbase_tree_cache {
1171         struct object_id oid;
1172         int ref;
1173         int temporary;
1174         void *tree_data;
1175         unsigned long tree_size;
1176 };
1177
1178 static struct pbase_tree_cache *(pbase_tree_cache[256]);
1179 static int pbase_tree_cache_ix(const struct object_id *oid)
1180 {
1181         return oid->hash[0] % ARRAY_SIZE(pbase_tree_cache);
1182 }
1183 static int pbase_tree_cache_ix_incr(int ix)
1184 {
1185         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
1186 }
1187
1188 static struct pbase_tree {
1189         struct pbase_tree *next;
1190         /* This is a phony "cache" entry; we are not
1191          * going to evict it or find it through _get()
1192          * mechanism -- this is for the toplevel node that
1193          * would almost always change with any commit.
1194          */
1195         struct pbase_tree_cache pcache;
1196 } *pbase_tree;
1197
1198 static struct pbase_tree_cache *pbase_tree_get(const struct object_id *oid)
1199 {
1200         struct pbase_tree_cache *ent, *nent;
1201         void *data;
1202         unsigned long size;
1203         enum object_type type;
1204         int neigh;
1205         int my_ix = pbase_tree_cache_ix(oid);
1206         int available_ix = -1;
1207
1208         /* pbase-tree-cache acts as a limited hashtable.
1209          * your object will be found at your index or within a few
1210          * slots after that slot if it is cached.
1211          */
1212         for (neigh = 0; neigh < 8; neigh++) {
1213                 ent = pbase_tree_cache[my_ix];
1214                 if (ent && !oidcmp(&ent->oid, oid)) {
1215                         ent->ref++;
1216                         return ent;
1217                 }
1218                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
1219                          ((0 <= available_ix) &&
1220                           (!ent && pbase_tree_cache[available_ix])))
1221                         available_ix = my_ix;
1222                 if (!ent)
1223                         break;
1224                 my_ix = pbase_tree_cache_ix_incr(my_ix);
1225         }
1226
1227         /* Did not find one.  Either we got a bogus request or
1228          * we need to read and perhaps cache.
1229          */
1230         data = read_object_file(oid, &type, &size);
1231         if (!data)
1232                 return NULL;
1233         if (type != OBJ_TREE) {
1234                 free(data);
1235                 return NULL;
1236         }
1237
1238         /* We need to either cache or return a throwaway copy */
1239
1240         if (available_ix < 0)
1241                 ent = NULL;
1242         else {
1243                 ent = pbase_tree_cache[available_ix];
1244                 my_ix = available_ix;
1245         }
1246
1247         if (!ent) {
1248                 nent = xmalloc(sizeof(*nent));
1249                 nent->temporary = (available_ix < 0);
1250         }
1251         else {
1252                 /* evict and reuse */
1253                 free(ent->tree_data);
1254                 nent = ent;
1255         }
1256         oidcpy(&nent->oid, oid);
1257         nent->tree_data = data;
1258         nent->tree_size = size;
1259         nent->ref = 1;
1260         if (!nent->temporary)
1261                 pbase_tree_cache[my_ix] = nent;
1262         return nent;
1263 }
1264
1265 static void pbase_tree_put(struct pbase_tree_cache *cache)
1266 {
1267         if (!cache->temporary) {
1268                 cache->ref--;
1269                 return;
1270         }
1271         free(cache->tree_data);
1272         free(cache);
1273 }
1274
1275 static int name_cmp_len(const char *name)
1276 {
1277         int i;
1278         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
1279                 ;
1280         return i;
1281 }
1282
1283 static void add_pbase_object(struct tree_desc *tree,
1284                              const char *name,
1285                              int cmplen,
1286                              const char *fullname)
1287 {
1288         struct name_entry entry;
1289         int cmp;
1290
1291         while (tree_entry(tree,&entry)) {
1292                 if (S_ISGITLINK(entry.mode))
1293                         continue;
1294                 cmp = tree_entry_len(&entry) != cmplen ? 1 :
1295                       memcmp(name, entry.path, cmplen);
1296                 if (cmp > 0)
1297                         continue;
1298                 if (cmp < 0)
1299                         return;
1300                 if (name[cmplen] != '/') {
1301                         add_object_entry(entry.oid,
1302                                          object_type(entry.mode),
1303                                          fullname, 1);
1304                         return;
1305                 }
1306                 if (S_ISDIR(entry.mode)) {
1307                         struct tree_desc sub;
1308                         struct pbase_tree_cache *tree;
1309                         const char *down = name+cmplen+1;
1310                         int downlen = name_cmp_len(down);
1311
1312                         tree = pbase_tree_get(entry.oid);
1313                         if (!tree)
1314                                 return;
1315                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1316
1317                         add_pbase_object(&sub, down, downlen, fullname);
1318                         pbase_tree_put(tree);
1319                 }
1320         }
1321 }
1322
1323 static unsigned *done_pbase_paths;
1324 static int done_pbase_paths_num;
1325 static int done_pbase_paths_alloc;
1326 static int done_pbase_path_pos(unsigned hash)
1327 {
1328         int lo = 0;
1329         int hi = done_pbase_paths_num;
1330         while (lo < hi) {
1331                 int mi = lo + (hi - lo) / 2;
1332                 if (done_pbase_paths[mi] == hash)
1333                         return mi;
1334                 if (done_pbase_paths[mi] < hash)
1335                         hi = mi;
1336                 else
1337                         lo = mi + 1;
1338         }
1339         return -lo-1;
1340 }
1341
1342 static int check_pbase_path(unsigned hash)
1343 {
1344         int pos = done_pbase_path_pos(hash);
1345         if (0 <= pos)
1346                 return 1;
1347         pos = -pos - 1;
1348         ALLOC_GROW(done_pbase_paths,
1349                    done_pbase_paths_num + 1,
1350                    done_pbase_paths_alloc);
1351         done_pbase_paths_num++;
1352         if (pos < done_pbase_paths_num)
1353                 MOVE_ARRAY(done_pbase_paths + pos + 1, done_pbase_paths + pos,
1354                            done_pbase_paths_num - pos - 1);
1355         done_pbase_paths[pos] = hash;
1356         return 0;
1357 }
1358
1359 static void add_preferred_base_object(const char *name)
1360 {
1361         struct pbase_tree *it;
1362         int cmplen;
1363         unsigned hash = pack_name_hash(name);
1364
1365         if (!num_preferred_base || check_pbase_path(hash))
1366                 return;
1367
1368         cmplen = name_cmp_len(name);
1369         for (it = pbase_tree; it; it = it->next) {
1370                 if (cmplen == 0) {
1371                         add_object_entry(&it->pcache.oid, OBJ_TREE, NULL, 1);
1372                 }
1373                 else {
1374                         struct tree_desc tree;
1375                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1376                         add_pbase_object(&tree, name, cmplen, name);
1377                 }
1378         }
1379 }
1380
1381 static void add_preferred_base(struct object_id *oid)
1382 {
1383         struct pbase_tree *it;
1384         void *data;
1385         unsigned long size;
1386         struct object_id tree_oid;
1387
1388         if (window <= num_preferred_base++)
1389                 return;
1390
1391         data = read_object_with_reference(oid, tree_type, &size, &tree_oid);
1392         if (!data)
1393                 return;
1394
1395         for (it = pbase_tree; it; it = it->next) {
1396                 if (!oidcmp(&it->pcache.oid, &tree_oid)) {
1397                         free(data);
1398                         return;
1399                 }
1400         }
1401
1402         it = xcalloc(1, sizeof(*it));
1403         it->next = pbase_tree;
1404         pbase_tree = it;
1405
1406         oidcpy(&it->pcache.oid, &tree_oid);
1407         it->pcache.tree_data = data;
1408         it->pcache.tree_size = size;
1409 }
1410
1411 static void cleanup_preferred_base(void)
1412 {
1413         struct pbase_tree *it;
1414         unsigned i;
1415
1416         it = pbase_tree;
1417         pbase_tree = NULL;
1418         while (it) {
1419                 struct pbase_tree *tmp = it;
1420                 it = tmp->next;
1421                 free(tmp->pcache.tree_data);
1422                 free(tmp);
1423         }
1424
1425         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1426                 if (!pbase_tree_cache[i])
1427                         continue;
1428                 free(pbase_tree_cache[i]->tree_data);
1429                 FREE_AND_NULL(pbase_tree_cache[i]);
1430         }
1431
1432         FREE_AND_NULL(done_pbase_paths);
1433         done_pbase_paths_num = done_pbase_paths_alloc = 0;
1434 }
1435
1436 static void check_object(struct object_entry *entry)
1437 {
1438         unsigned long canonical_size;
1439
1440         if (IN_PACK(entry)) {
1441                 struct packed_git *p = IN_PACK(entry);
1442                 struct pack_window *w_curs = NULL;
1443                 const unsigned char *base_ref = NULL;
1444                 struct object_entry *base_entry;
1445                 unsigned long used, used_0;
1446                 unsigned long avail;
1447                 off_t ofs;
1448                 unsigned char *buf, c;
1449                 enum object_type type;
1450                 unsigned long in_pack_size;
1451
1452                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1453
1454                 /*
1455                  * We want in_pack_type even if we do not reuse delta
1456                  * since non-delta representations could still be reused.
1457                  */
1458                 used = unpack_object_header_buffer(buf, avail,
1459                                                    &type,
1460                                                    &in_pack_size);
1461                 if (used == 0)
1462                         goto give_up;
1463
1464                 if (type < 0)
1465                         BUG("invalid type %d", type);
1466                 entry->in_pack_type = type;
1467
1468                 /*
1469                  * Determine if this is a delta and if so whether we can
1470                  * reuse it or not.  Otherwise let's find out as cheaply as
1471                  * possible what the actual type and size for this object is.
1472                  */
1473                 switch (entry->in_pack_type) {
1474                 default:
1475                         /* Not a delta hence we've already got all we need. */
1476                         oe_set_type(entry, entry->in_pack_type);
1477                         SET_SIZE(entry, in_pack_size);
1478                         entry->in_pack_header_size = used;
1479                         if (oe_type(entry) < OBJ_COMMIT || oe_type(entry) > OBJ_BLOB)
1480                                 goto give_up;
1481                         unuse_pack(&w_curs);
1482                         return;
1483                 case OBJ_REF_DELTA:
1484                         if (reuse_delta && !entry->preferred_base)
1485                                 base_ref = use_pack(p, &w_curs,
1486                                                 entry->in_pack_offset + used, NULL);
1487                         entry->in_pack_header_size = used + the_hash_algo->rawsz;
1488                         break;
1489                 case OBJ_OFS_DELTA:
1490                         buf = use_pack(p, &w_curs,
1491                                        entry->in_pack_offset + used, NULL);
1492                         used_0 = 0;
1493                         c = buf[used_0++];
1494                         ofs = c & 127;
1495                         while (c & 128) {
1496                                 ofs += 1;
1497                                 if (!ofs || MSB(ofs, 7)) {
1498                                         error("delta base offset overflow in pack for %s",
1499                                               oid_to_hex(&entry->idx.oid));
1500                                         goto give_up;
1501                                 }
1502                                 c = buf[used_0++];
1503                                 ofs = (ofs << 7) + (c & 127);
1504                         }
1505                         ofs = entry->in_pack_offset - ofs;
1506                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1507                                 error("delta base offset out of bound for %s",
1508                                       oid_to_hex(&entry->idx.oid));
1509                                 goto give_up;
1510                         }
1511                         if (reuse_delta && !entry->preferred_base) {
1512                                 struct revindex_entry *revidx;
1513                                 revidx = find_pack_revindex(p, ofs);
1514                                 if (!revidx)
1515                                         goto give_up;
1516                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1517                         }
1518                         entry->in_pack_header_size = used + used_0;
1519                         break;
1520                 }
1521
1522                 if (base_ref && (base_entry = packlist_find(&to_pack, base_ref, NULL)) &&
1523                     in_same_island(&entry->idx.oid, &base_entry->idx.oid)) {
1524                         /*
1525                          * If base_ref was set above that means we wish to
1526                          * reuse delta data, and we even found that base
1527                          * in the list of objects we want to pack. Goodie!
1528                          *
1529                          * Depth value does not matter - find_deltas() will
1530                          * never consider reused delta as the base object to
1531                          * deltify other objects against, in order to avoid
1532                          * circular deltas.
1533                          */
1534                         oe_set_type(entry, entry->in_pack_type);
1535                         SET_SIZE(entry, in_pack_size); /* delta size */
1536                         SET_DELTA(entry, base_entry);
1537                         SET_DELTA_SIZE(entry, in_pack_size);
1538                         entry->delta_sibling_idx = base_entry->delta_child_idx;
1539                         SET_DELTA_CHILD(base_entry, entry);
1540                         unuse_pack(&w_curs);
1541                         return;
1542                 }
1543
1544                 if (oe_type(entry)) {
1545                         off_t delta_pos;
1546
1547                         /*
1548                          * This must be a delta and we already know what the
1549                          * final object type is.  Let's extract the actual
1550                          * object size from the delta header.
1551                          */
1552                         delta_pos = entry->in_pack_offset + entry->in_pack_header_size;
1553                         canonical_size = get_size_from_delta(p, &w_curs, delta_pos);
1554                         if (canonical_size == 0)
1555                                 goto give_up;
1556                         SET_SIZE(entry, canonical_size);
1557                         unuse_pack(&w_curs);
1558                         return;
1559                 }
1560
1561                 /*
1562                  * No choice but to fall back to the recursive delta walk
1563                  * with sha1_object_info() to find about the object type
1564                  * at this point...
1565                  */
1566                 give_up:
1567                 unuse_pack(&w_curs);
1568         }
1569
1570         oe_set_type(entry,
1571                     oid_object_info(the_repository, &entry->idx.oid, &canonical_size));
1572         if (entry->type_valid) {
1573                 SET_SIZE(entry, canonical_size);
1574         } else {
1575                 /*
1576                  * Bad object type is checked in prepare_pack().  This is
1577                  * to permit a missing preferred base object to be ignored
1578                  * as a preferred base.  Doing so can result in a larger
1579                  * pack file, but the transfer will still take place.
1580                  */
1581         }
1582 }
1583
1584 static int pack_offset_sort(const void *_a, const void *_b)
1585 {
1586         const struct object_entry *a = *(struct object_entry **)_a;
1587         const struct object_entry *b = *(struct object_entry **)_b;
1588         const struct packed_git *a_in_pack = IN_PACK(a);
1589         const struct packed_git *b_in_pack = IN_PACK(b);
1590
1591         /* avoid filesystem trashing with loose objects */
1592         if (!a_in_pack && !b_in_pack)
1593                 return oidcmp(&a->idx.oid, &b->idx.oid);
1594
1595         if (a_in_pack < b_in_pack)
1596                 return -1;
1597         if (a_in_pack > b_in_pack)
1598                 return 1;
1599         return a->in_pack_offset < b->in_pack_offset ? -1 :
1600                         (a->in_pack_offset > b->in_pack_offset);
1601 }
1602
1603 /*
1604  * Drop an on-disk delta we were planning to reuse. Naively, this would
1605  * just involve blanking out the "delta" field, but we have to deal
1606  * with some extra book-keeping:
1607  *
1608  *   1. Removing ourselves from the delta_sibling linked list.
1609  *
1610  *   2. Updating our size/type to the non-delta representation. These were
1611  *      either not recorded initially (size) or overwritten with the delta type
1612  *      (type) when check_object() decided to reuse the delta.
1613  *
1614  *   3. Resetting our delta depth, as we are now a base object.
1615  */
1616 static void drop_reused_delta(struct object_entry *entry)
1617 {
1618         unsigned *idx = &to_pack.objects[entry->delta_idx - 1].delta_child_idx;
1619         struct object_info oi = OBJECT_INFO_INIT;
1620         enum object_type type;
1621         unsigned long size;
1622
1623         while (*idx) {
1624                 struct object_entry *oe = &to_pack.objects[*idx - 1];
1625
1626                 if (oe == entry)
1627                         *idx = oe->delta_sibling_idx;
1628                 else
1629                         idx = &oe->delta_sibling_idx;
1630         }
1631         SET_DELTA(entry, NULL);
1632         entry->depth = 0;
1633
1634         oi.sizep = &size;
1635         oi.typep = &type;
1636         if (packed_object_info(the_repository, IN_PACK(entry), entry->in_pack_offset, &oi) < 0) {
1637                 /*
1638                  * We failed to get the info from this pack for some reason;
1639                  * fall back to sha1_object_info, which may find another copy.
1640                  * And if that fails, the error will be recorded in oe_type(entry)
1641                  * and dealt with in prepare_pack().
1642                  */
1643                 oe_set_type(entry,
1644                             oid_object_info(the_repository, &entry->idx.oid, &size));
1645         } else {
1646                 oe_set_type(entry, type);
1647         }
1648         SET_SIZE(entry, size);
1649 }
1650
1651 /*
1652  * Follow the chain of deltas from this entry onward, throwing away any links
1653  * that cause us to hit a cycle (as determined by the DFS state flags in
1654  * the entries).
1655  *
1656  * We also detect too-long reused chains that would violate our --depth
1657  * limit.
1658  */
1659 static void break_delta_chains(struct object_entry *entry)
1660 {
1661         /*
1662          * The actual depth of each object we will write is stored as an int,
1663          * as it cannot exceed our int "depth" limit. But before we break
1664          * changes based no that limit, we may potentially go as deep as the
1665          * number of objects, which is elsewhere bounded to a uint32_t.
1666          */
1667         uint32_t total_depth;
1668         struct object_entry *cur, *next;
1669
1670         for (cur = entry, total_depth = 0;
1671              cur;
1672              cur = DELTA(cur), total_depth++) {
1673                 if (cur->dfs_state == DFS_DONE) {
1674                         /*
1675                          * We've already seen this object and know it isn't
1676                          * part of a cycle. We do need to append its depth
1677                          * to our count.
1678                          */
1679                         total_depth += cur->depth;
1680                         break;
1681                 }
1682
1683                 /*
1684                  * We break cycles before looping, so an ACTIVE state (or any
1685                  * other cruft which made its way into the state variable)
1686                  * is a bug.
1687                  */
1688                 if (cur->dfs_state != DFS_NONE)
1689                         BUG("confusing delta dfs state in first pass: %d",
1690                             cur->dfs_state);
1691
1692                 /*
1693                  * Now we know this is the first time we've seen the object. If
1694                  * it's not a delta, we're done traversing, but we'll mark it
1695                  * done to save time on future traversals.
1696                  */
1697                 if (!DELTA(cur)) {
1698                         cur->dfs_state = DFS_DONE;
1699                         break;
1700                 }
1701
1702                 /*
1703                  * Mark ourselves as active and see if the next step causes
1704                  * us to cycle to another active object. It's important to do
1705                  * this _before_ we loop, because it impacts where we make the
1706                  * cut, and thus how our total_depth counter works.
1707                  * E.g., We may see a partial loop like:
1708                  *
1709                  *   A -> B -> C -> D -> B
1710                  *
1711                  * Cutting B->C breaks the cycle. But now the depth of A is
1712                  * only 1, and our total_depth counter is at 3. The size of the
1713                  * error is always one less than the size of the cycle we
1714                  * broke. Commits C and D were "lost" from A's chain.
1715                  *
1716                  * If we instead cut D->B, then the depth of A is correct at 3.
1717                  * We keep all commits in the chain that we examined.
1718                  */
1719                 cur->dfs_state = DFS_ACTIVE;
1720                 if (DELTA(cur)->dfs_state == DFS_ACTIVE) {
1721                         drop_reused_delta(cur);
1722                         cur->dfs_state = DFS_DONE;
1723                         break;
1724                 }
1725         }
1726
1727         /*
1728          * And now that we've gone all the way to the bottom of the chain, we
1729          * need to clear the active flags and set the depth fields as
1730          * appropriate. Unlike the loop above, which can quit when it drops a
1731          * delta, we need to keep going to look for more depth cuts. So we need
1732          * an extra "next" pointer to keep going after we reset cur->delta.
1733          */
1734         for (cur = entry; cur; cur = next) {
1735                 next = DELTA(cur);
1736
1737                 /*
1738                  * We should have a chain of zero or more ACTIVE states down to
1739                  * a final DONE. We can quit after the DONE, because either it
1740                  * has no bases, or we've already handled them in a previous
1741                  * call.
1742                  */
1743                 if (cur->dfs_state == DFS_DONE)
1744                         break;
1745                 else if (cur->dfs_state != DFS_ACTIVE)
1746                         BUG("confusing delta dfs state in second pass: %d",
1747                             cur->dfs_state);
1748
1749                 /*
1750                  * If the total_depth is more than depth, then we need to snip
1751                  * the chain into two or more smaller chains that don't exceed
1752                  * the maximum depth. Most of the resulting chains will contain
1753                  * (depth + 1) entries (i.e., depth deltas plus one base), and
1754                  * the last chain (i.e., the one containing entry) will contain
1755                  * whatever entries are left over, namely
1756                  * (total_depth % (depth + 1)) of them.
1757                  *
1758                  * Since we are iterating towards decreasing depth, we need to
1759                  * decrement total_depth as we go, and we need to write to the
1760                  * entry what its final depth will be after all of the
1761                  * snipping. Since we're snipping into chains of length (depth
1762                  * + 1) entries, the final depth of an entry will be its
1763                  * original depth modulo (depth + 1). Any time we encounter an
1764                  * entry whose final depth is supposed to be zero, we snip it
1765                  * from its delta base, thereby making it so.
1766                  */
1767                 cur->depth = (total_depth--) % (depth + 1);
1768                 if (!cur->depth)
1769                         drop_reused_delta(cur);
1770
1771                 cur->dfs_state = DFS_DONE;
1772         }
1773 }
1774
1775 static void get_object_details(void)
1776 {
1777         uint32_t i;
1778         struct object_entry **sorted_by_offset;
1779
1780         if (progress)
1781                 progress_state = start_progress(_("Counting objects"),
1782                                                 to_pack.nr_objects);
1783
1784         sorted_by_offset = xcalloc(to_pack.nr_objects, sizeof(struct object_entry *));
1785         for (i = 0; i < to_pack.nr_objects; i++)
1786                 sorted_by_offset[i] = to_pack.objects + i;
1787         QSORT(sorted_by_offset, to_pack.nr_objects, pack_offset_sort);
1788
1789         for (i = 0; i < to_pack.nr_objects; i++) {
1790                 struct object_entry *entry = sorted_by_offset[i];
1791                 check_object(entry);
1792                 if (entry->type_valid &&
1793                     oe_size_greater_than(&to_pack, entry, big_file_threshold))
1794                         entry->no_try_delta = 1;
1795                 display_progress(progress_state, i + 1);
1796         }
1797         stop_progress(&progress_state);
1798
1799         /*
1800          * This must happen in a second pass, since we rely on the delta
1801          * information for the whole list being completed.
1802          */
1803         for (i = 0; i < to_pack.nr_objects; i++)
1804                 break_delta_chains(&to_pack.objects[i]);
1805
1806         free(sorted_by_offset);
1807 }
1808
1809 /*
1810  * We search for deltas in a list sorted by type, by filename hash, and then
1811  * by size, so that we see progressively smaller and smaller files.
1812  * That's because we prefer deltas to be from the bigger file
1813  * to the smaller -- deletes are potentially cheaper, but perhaps
1814  * more importantly, the bigger file is likely the more recent
1815  * one.  The deepest deltas are therefore the oldest objects which are
1816  * less susceptible to be accessed often.
1817  */
1818 static int type_size_sort(const void *_a, const void *_b)
1819 {
1820         const struct object_entry *a = *(struct object_entry **)_a;
1821         const struct object_entry *b = *(struct object_entry **)_b;
1822         enum object_type a_type = oe_type(a);
1823         enum object_type b_type = oe_type(b);
1824         unsigned long a_size = SIZE(a);
1825         unsigned long b_size = SIZE(b);
1826
1827         if (a_type > b_type)
1828                 return -1;
1829         if (a_type < b_type)
1830                 return 1;
1831         if (a->hash > b->hash)
1832                 return -1;
1833         if (a->hash < b->hash)
1834                 return 1;
1835         if (a->preferred_base > b->preferred_base)
1836                 return -1;
1837         if (a->preferred_base < b->preferred_base)
1838                 return 1;
1839         if (use_delta_islands) {
1840                 int island_cmp = island_delta_cmp(&a->idx.oid, &b->idx.oid);
1841                 if (island_cmp)
1842                         return island_cmp;
1843         }
1844         if (a_size > b_size)
1845                 return -1;
1846         if (a_size < b_size)
1847                 return 1;
1848         return a < b ? -1 : (a > b);  /* newest first */
1849 }
1850
1851 struct unpacked {
1852         struct object_entry *entry;
1853         void *data;
1854         struct delta_index *index;
1855         unsigned depth;
1856 };
1857
1858 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1859                            unsigned long delta_size)
1860 {
1861         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1862                 return 0;
1863
1864         if (delta_size < cache_max_small_delta_size)
1865                 return 1;
1866
1867         /* cache delta, if objects are large enough compared to delta size */
1868         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1869                 return 1;
1870
1871         return 0;
1872 }
1873
1874 #ifndef NO_PTHREADS
1875
1876 static pthread_mutex_t read_mutex;
1877 #define read_lock()             pthread_mutex_lock(&read_mutex)
1878 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1879
1880 static pthread_mutex_t cache_mutex;
1881 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1882 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1883
1884 static pthread_mutex_t progress_mutex;
1885 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1886 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1887
1888 #else
1889
1890 #define read_lock()             (void)0
1891 #define read_unlock()           (void)0
1892 #define cache_lock()            (void)0
1893 #define cache_unlock()          (void)0
1894 #define progress_lock()         (void)0
1895 #define progress_unlock()       (void)0
1896
1897 #endif
1898
1899 /*
1900  * Return the size of the object without doing any delta
1901  * reconstruction (so non-deltas are true object sizes, but deltas
1902  * return the size of the delta data).
1903  */
1904 unsigned long oe_get_size_slow(struct packing_data *pack,
1905                                const struct object_entry *e)
1906 {
1907         struct packed_git *p;
1908         struct pack_window *w_curs;
1909         unsigned char *buf;
1910         enum object_type type;
1911         unsigned long used, avail, size;
1912
1913         if (e->type_ != OBJ_OFS_DELTA && e->type_ != OBJ_REF_DELTA) {
1914                 read_lock();
1915                 if (oid_object_info(the_repository, &e->idx.oid, &size) < 0)
1916                         die(_("unable to get size of %s"),
1917                             oid_to_hex(&e->idx.oid));
1918                 read_unlock();
1919                 return size;
1920         }
1921
1922         p = oe_in_pack(pack, e);
1923         if (!p)
1924                 BUG("when e->type is a delta, it must belong to a pack");
1925
1926         read_lock();
1927         w_curs = NULL;
1928         buf = use_pack(p, &w_curs, e->in_pack_offset, &avail);
1929         used = unpack_object_header_buffer(buf, avail, &type, &size);
1930         if (used == 0)
1931                 die(_("unable to parse object header of %s"),
1932                     oid_to_hex(&e->idx.oid));
1933
1934         unuse_pack(&w_curs);
1935         read_unlock();
1936         return size;
1937 }
1938
1939 static int try_delta(struct unpacked *trg, struct unpacked *src,
1940                      unsigned max_depth, unsigned long *mem_usage)
1941 {
1942         struct object_entry *trg_entry = trg->entry;
1943         struct object_entry *src_entry = src->entry;
1944         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1945         unsigned ref_depth;
1946         enum object_type type;
1947         void *delta_buf;
1948
1949         /* Don't bother doing diffs between different types */
1950         if (oe_type(trg_entry) != oe_type(src_entry))
1951                 return -1;
1952
1953         /*
1954          * We do not bother to try a delta that we discarded on an
1955          * earlier try, but only when reusing delta data.  Note that
1956          * src_entry that is marked as the preferred_base should always
1957          * be considered, as even if we produce a suboptimal delta against
1958          * it, we will still save the transfer cost, as we already know
1959          * the other side has it and we won't send src_entry at all.
1960          */
1961         if (reuse_delta && IN_PACK(trg_entry) &&
1962             IN_PACK(trg_entry) == IN_PACK(src_entry) &&
1963             !src_entry->preferred_base &&
1964             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1965             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1966                 return 0;
1967
1968         /* Let's not bust the allowed depth. */
1969         if (src->depth >= max_depth)
1970                 return 0;
1971
1972         /* Now some size filtering heuristics. */
1973         trg_size = SIZE(trg_entry);
1974         if (!DELTA(trg_entry)) {
1975                 max_size = trg_size/2 - the_hash_algo->rawsz;
1976                 ref_depth = 1;
1977         } else {
1978                 max_size = DELTA_SIZE(trg_entry);
1979                 ref_depth = trg->depth;
1980         }
1981         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1982                                                 (max_depth - ref_depth + 1);
1983         if (max_size == 0)
1984                 return 0;
1985         src_size = SIZE(src_entry);
1986         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1987         if (sizediff >= max_size)
1988                 return 0;
1989         if (trg_size < src_size / 32)
1990                 return 0;
1991
1992         if (!in_same_island(&trg->entry->idx.oid, &src->entry->idx.oid))
1993                 return 0;
1994
1995         /* Load data if not already done */
1996         if (!trg->data) {
1997                 read_lock();
1998                 trg->data = read_object_file(&trg_entry->idx.oid, &type, &sz);
1999                 read_unlock();
2000                 if (!trg->data)
2001                         die("object %s cannot be read",
2002                             oid_to_hex(&trg_entry->idx.oid));
2003                 if (sz != trg_size)
2004                         die("object %s inconsistent object length (%lu vs %lu)",
2005                             oid_to_hex(&trg_entry->idx.oid), sz,
2006                             trg_size);
2007                 *mem_usage += sz;
2008         }
2009         if (!src->data) {
2010                 read_lock();
2011                 src->data = read_object_file(&src_entry->idx.oid, &type, &sz);
2012                 read_unlock();
2013                 if (!src->data) {
2014                         if (src_entry->preferred_base) {
2015                                 static int warned = 0;
2016                                 if (!warned++)
2017                                         warning("object %s cannot be read",
2018                                                 oid_to_hex(&src_entry->idx.oid));
2019                                 /*
2020                                  * Those objects are not included in the
2021                                  * resulting pack.  Be resilient and ignore
2022                                  * them if they can't be read, in case the
2023                                  * pack could be created nevertheless.
2024                                  */
2025                                 return 0;
2026                         }
2027                         die("object %s cannot be read",
2028                             oid_to_hex(&src_entry->idx.oid));
2029                 }
2030                 if (sz != src_size)
2031                         die("object %s inconsistent object length (%lu vs %lu)",
2032                             oid_to_hex(&src_entry->idx.oid), sz,
2033                             src_size);
2034                 *mem_usage += sz;
2035         }
2036         if (!src->index) {
2037                 src->index = create_delta_index(src->data, src_size);
2038                 if (!src->index) {
2039                         static int warned = 0;
2040                         if (!warned++)
2041                                 warning("suboptimal pack - out of memory");
2042                         return 0;
2043                 }
2044                 *mem_usage += sizeof_delta_index(src->index);
2045         }
2046
2047         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
2048         if (!delta_buf)
2049                 return 0;
2050         if (delta_size >= (1U << OE_DELTA_SIZE_BITS)) {
2051                 free(delta_buf);
2052                 return 0;
2053         }
2054
2055         if (DELTA(trg_entry)) {
2056                 /* Prefer only shallower same-sized deltas. */
2057                 if (delta_size == DELTA_SIZE(trg_entry) &&
2058                     src->depth + 1 >= trg->depth) {
2059                         free(delta_buf);
2060                         return 0;
2061                 }
2062         }
2063
2064         /*
2065          * Handle memory allocation outside of the cache
2066          * accounting lock.  Compiler will optimize the strangeness
2067          * away when NO_PTHREADS is defined.
2068          */
2069         free(trg_entry->delta_data);
2070         cache_lock();
2071         if (trg_entry->delta_data) {
2072                 delta_cache_size -= DELTA_SIZE(trg_entry);
2073                 trg_entry->delta_data = NULL;
2074         }
2075         if (delta_cacheable(src_size, trg_size, delta_size)) {
2076                 delta_cache_size += delta_size;
2077                 cache_unlock();
2078                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
2079         } else {
2080                 cache_unlock();
2081                 free(delta_buf);
2082         }
2083
2084         SET_DELTA(trg_entry, src_entry);
2085         SET_DELTA_SIZE(trg_entry, delta_size);
2086         trg->depth = src->depth + 1;
2087
2088         return 1;
2089 }
2090
2091 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
2092 {
2093         struct object_entry *child = DELTA_CHILD(me);
2094         unsigned int m = n;
2095         while (child) {
2096                 unsigned int c = check_delta_limit(child, n + 1);
2097                 if (m < c)
2098                         m = c;
2099                 child = DELTA_SIBLING(child);
2100         }
2101         return m;
2102 }
2103
2104 static unsigned long free_unpacked(struct unpacked *n)
2105 {
2106         unsigned long freed_mem = sizeof_delta_index(n->index);
2107         free_delta_index(n->index);
2108         n->index = NULL;
2109         if (n->data) {
2110                 freed_mem += SIZE(n->entry);
2111                 FREE_AND_NULL(n->data);
2112         }
2113         n->entry = NULL;
2114         n->depth = 0;
2115         return freed_mem;
2116 }
2117
2118 static void find_deltas(struct object_entry **list, unsigned *list_size,
2119                         int window, int depth, unsigned *processed)
2120 {
2121         uint32_t i, idx = 0, count = 0;
2122         struct unpacked *array;
2123         unsigned long mem_usage = 0;
2124
2125         array = xcalloc(window, sizeof(struct unpacked));
2126
2127         for (;;) {
2128                 struct object_entry *entry;
2129                 struct unpacked *n = array + idx;
2130                 int j, max_depth, best_base = -1;
2131
2132                 progress_lock();
2133                 if (!*list_size) {
2134                         progress_unlock();
2135                         break;
2136                 }
2137                 entry = *list++;
2138                 (*list_size)--;
2139                 if (!entry->preferred_base) {
2140                         (*processed)++;
2141                         display_progress(progress_state, *processed);
2142                 }
2143                 progress_unlock();
2144
2145                 mem_usage -= free_unpacked(n);
2146                 n->entry = entry;
2147
2148                 while (window_memory_limit &&
2149                        mem_usage > window_memory_limit &&
2150                        count > 1) {
2151                         uint32_t tail = (idx + window - count) % window;
2152                         mem_usage -= free_unpacked(array + tail);
2153                         count--;
2154                 }
2155
2156                 /* We do not compute delta to *create* objects we are not
2157                  * going to pack.
2158                  */
2159                 if (entry->preferred_base)
2160                         goto next;
2161
2162                 /*
2163                  * If the current object is at pack edge, take the depth the
2164                  * objects that depend on the current object into account
2165                  * otherwise they would become too deep.
2166                  */
2167                 max_depth = depth;
2168                 if (DELTA_CHILD(entry)) {
2169                         max_depth -= check_delta_limit(entry, 0);
2170                         if (max_depth <= 0)
2171                                 goto next;
2172                 }
2173
2174                 j = window;
2175                 while (--j > 0) {
2176                         int ret;
2177                         uint32_t other_idx = idx + j;
2178                         struct unpacked *m;
2179                         if (other_idx >= window)
2180                                 other_idx -= window;
2181                         m = array + other_idx;
2182                         if (!m->entry)
2183                                 break;
2184                         ret = try_delta(n, m, max_depth, &mem_usage);
2185                         if (ret < 0)
2186                                 break;
2187                         else if (ret > 0)
2188                                 best_base = other_idx;
2189                 }
2190
2191                 /*
2192                  * If we decided to cache the delta data, then it is best
2193                  * to compress it right away.  First because we have to do
2194                  * it anyway, and doing it here while we're threaded will
2195                  * save a lot of time in the non threaded write phase,
2196                  * as well as allow for caching more deltas within
2197                  * the same cache size limit.
2198                  * ...
2199                  * But only if not writing to stdout, since in that case
2200                  * the network is most likely throttling writes anyway,
2201                  * and therefore it is best to go to the write phase ASAP
2202                  * instead, as we can afford spending more time compressing
2203                  * between writes at that moment.
2204                  */
2205                 if (entry->delta_data && !pack_to_stdout) {
2206                         unsigned long size;
2207
2208                         size = do_compress(&entry->delta_data, DELTA_SIZE(entry));
2209                         if (size < (1U << OE_Z_DELTA_BITS)) {
2210                                 entry->z_delta_size = size;
2211                                 cache_lock();
2212                                 delta_cache_size -= DELTA_SIZE(entry);
2213                                 delta_cache_size += entry->z_delta_size;
2214                                 cache_unlock();
2215                         } else {
2216                                 FREE_AND_NULL(entry->delta_data);
2217                                 entry->z_delta_size = 0;
2218                         }
2219                 }
2220
2221                 /* if we made n a delta, and if n is already at max
2222                  * depth, leaving it in the window is pointless.  we
2223                  * should evict it first.
2224                  */
2225                 if (DELTA(entry) && max_depth <= n->depth)
2226                         continue;
2227
2228                 /*
2229                  * Move the best delta base up in the window, after the
2230                  * currently deltified object, to keep it longer.  It will
2231                  * be the first base object to be attempted next.
2232                  */
2233                 if (DELTA(entry)) {
2234                         struct unpacked swap = array[best_base];
2235                         int dist = (window + idx - best_base) % window;
2236                         int dst = best_base;
2237                         while (dist--) {
2238                                 int src = (dst + 1) % window;
2239                                 array[dst] = array[src];
2240                                 dst = src;
2241                         }
2242                         array[dst] = swap;
2243                 }
2244
2245                 next:
2246                 idx++;
2247                 if (count + 1 < window)
2248                         count++;
2249                 if (idx >= window)
2250                         idx = 0;
2251         }
2252
2253         for (i = 0; i < window; ++i) {
2254                 free_delta_index(array[i].index);
2255                 free(array[i].data);
2256         }
2257         free(array);
2258 }
2259
2260 #ifndef NO_PTHREADS
2261
2262 static void try_to_free_from_threads(size_t size)
2263 {
2264         read_lock();
2265         release_pack_memory(size);
2266         read_unlock();
2267 }
2268
2269 static try_to_free_t old_try_to_free_routine;
2270
2271 /*
2272  * The main thread waits on the condition that (at least) one of the workers
2273  * has stopped working (which is indicated in the .working member of
2274  * struct thread_params).
2275  * When a work thread has completed its work, it sets .working to 0 and
2276  * signals the main thread and waits on the condition that .data_ready
2277  * becomes 1.
2278  */
2279
2280 struct thread_params {
2281         pthread_t thread;
2282         struct object_entry **list;
2283         unsigned list_size;
2284         unsigned remaining;
2285         int window;
2286         int depth;
2287         int working;
2288         int data_ready;
2289         pthread_mutex_t mutex;
2290         pthread_cond_t cond;
2291         unsigned *processed;
2292 };
2293
2294 static pthread_cond_t progress_cond;
2295
2296 /*
2297  * Mutex and conditional variable can't be statically-initialized on Windows.
2298  */
2299 static void init_threaded_search(void)
2300 {
2301         init_recursive_mutex(&read_mutex);
2302         pthread_mutex_init(&cache_mutex, NULL);
2303         pthread_mutex_init(&progress_mutex, NULL);
2304         pthread_cond_init(&progress_cond, NULL);
2305         old_try_to_free_routine = set_try_to_free_routine(try_to_free_from_threads);
2306 }
2307
2308 static void cleanup_threaded_search(void)
2309 {
2310         set_try_to_free_routine(old_try_to_free_routine);
2311         pthread_cond_destroy(&progress_cond);
2312         pthread_mutex_destroy(&read_mutex);
2313         pthread_mutex_destroy(&cache_mutex);
2314         pthread_mutex_destroy(&progress_mutex);
2315 }
2316
2317 static void *threaded_find_deltas(void *arg)
2318 {
2319         struct thread_params *me = arg;
2320
2321         progress_lock();
2322         while (me->remaining) {
2323                 progress_unlock();
2324
2325                 find_deltas(me->list, &me->remaining,
2326                             me->window, me->depth, me->processed);
2327
2328                 progress_lock();
2329                 me->working = 0;
2330                 pthread_cond_signal(&progress_cond);
2331                 progress_unlock();
2332
2333                 /*
2334                  * We must not set ->data_ready before we wait on the
2335                  * condition because the main thread may have set it to 1
2336                  * before we get here. In order to be sure that new
2337                  * work is available if we see 1 in ->data_ready, it
2338                  * was initialized to 0 before this thread was spawned
2339                  * and we reset it to 0 right away.
2340                  */
2341                 pthread_mutex_lock(&me->mutex);
2342                 while (!me->data_ready)
2343                         pthread_cond_wait(&me->cond, &me->mutex);
2344                 me->data_ready = 0;
2345                 pthread_mutex_unlock(&me->mutex);
2346
2347                 progress_lock();
2348         }
2349         progress_unlock();
2350         /* leave ->working 1 so that this doesn't get more work assigned */
2351         return NULL;
2352 }
2353
2354 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
2355                            int window, int depth, unsigned *processed)
2356 {
2357         struct thread_params *p;
2358         int i, ret, active_threads = 0;
2359
2360         init_threaded_search();
2361
2362         if (delta_search_threads <= 1) {
2363                 find_deltas(list, &list_size, window, depth, processed);
2364                 cleanup_threaded_search();
2365                 return;
2366         }
2367         if (progress > pack_to_stdout)
2368                 fprintf(stderr, "Delta compression using up to %d threads.\n",
2369                                 delta_search_threads);
2370         p = xcalloc(delta_search_threads, sizeof(*p));
2371
2372         /* Partition the work amongst work threads. */
2373         for (i = 0; i < delta_search_threads; i++) {
2374                 unsigned sub_size = list_size / (delta_search_threads - i);
2375
2376                 /* don't use too small segments or no deltas will be found */
2377                 if (sub_size < 2*window && i+1 < delta_search_threads)
2378                         sub_size = 0;
2379
2380                 p[i].window = window;
2381                 p[i].depth = depth;
2382                 p[i].processed = processed;
2383                 p[i].working = 1;
2384                 p[i].data_ready = 0;
2385
2386                 /* try to split chunks on "path" boundaries */
2387                 while (sub_size && sub_size < list_size &&
2388                        list[sub_size]->hash &&
2389                        list[sub_size]->hash == list[sub_size-1]->hash)
2390                         sub_size++;
2391
2392                 p[i].list = list;
2393                 p[i].list_size = sub_size;
2394                 p[i].remaining = sub_size;
2395
2396                 list += sub_size;
2397                 list_size -= sub_size;
2398         }
2399
2400         /* Start work threads. */
2401         for (i = 0; i < delta_search_threads; i++) {
2402                 if (!p[i].list_size)
2403                         continue;
2404                 pthread_mutex_init(&p[i].mutex, NULL);
2405                 pthread_cond_init(&p[i].cond, NULL);
2406                 ret = pthread_create(&p[i].thread, NULL,
2407                                      threaded_find_deltas, &p[i]);
2408                 if (ret)
2409                         die("unable to create thread: %s", strerror(ret));
2410                 active_threads++;
2411         }
2412
2413         /*
2414          * Now let's wait for work completion.  Each time a thread is done
2415          * with its work, we steal half of the remaining work from the
2416          * thread with the largest number of unprocessed objects and give
2417          * it to that newly idle thread.  This ensure good load balancing
2418          * until the remaining object list segments are simply too short
2419          * to be worth splitting anymore.
2420          */
2421         while (active_threads) {
2422                 struct thread_params *target = NULL;
2423                 struct thread_params *victim = NULL;
2424                 unsigned sub_size = 0;
2425
2426                 progress_lock();
2427                 for (;;) {
2428                         for (i = 0; !target && i < delta_search_threads; i++)
2429                                 if (!p[i].working)
2430                                         target = &p[i];
2431                         if (target)
2432                                 break;
2433                         pthread_cond_wait(&progress_cond, &progress_mutex);
2434                 }
2435
2436                 for (i = 0; i < delta_search_threads; i++)
2437                         if (p[i].remaining > 2*window &&
2438                             (!victim || victim->remaining < p[i].remaining))
2439                                 victim = &p[i];
2440                 if (victim) {
2441                         sub_size = victim->remaining / 2;
2442                         list = victim->list + victim->list_size - sub_size;
2443                         while (sub_size && list[0]->hash &&
2444                                list[0]->hash == list[-1]->hash) {
2445                                 list++;
2446                                 sub_size--;
2447                         }
2448                         if (!sub_size) {
2449                                 /*
2450                                  * It is possible for some "paths" to have
2451                                  * so many objects that no hash boundary
2452                                  * might be found.  Let's just steal the
2453                                  * exact half in that case.
2454                                  */
2455                                 sub_size = victim->remaining / 2;
2456                                 list -= sub_size;
2457                         }
2458                         target->list = list;
2459                         victim->list_size -= sub_size;
2460                         victim->remaining -= sub_size;
2461                 }
2462                 target->list_size = sub_size;
2463                 target->remaining = sub_size;
2464                 target->working = 1;
2465                 progress_unlock();
2466
2467                 pthread_mutex_lock(&target->mutex);
2468                 target->data_ready = 1;
2469                 pthread_cond_signal(&target->cond);
2470                 pthread_mutex_unlock(&target->mutex);
2471
2472                 if (!sub_size) {
2473                         pthread_join(target->thread, NULL);
2474                         pthread_cond_destroy(&target->cond);
2475                         pthread_mutex_destroy(&target->mutex);
2476                         active_threads--;
2477                 }
2478         }
2479         cleanup_threaded_search();
2480         free(p);
2481 }
2482
2483 #else
2484 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
2485 #endif
2486
2487 static void add_tag_chain(const struct object_id *oid)
2488 {
2489         struct tag *tag;
2490
2491         /*
2492          * We catch duplicates already in add_object_entry(), but we'd
2493          * prefer to do this extra check to avoid having to parse the
2494          * tag at all if we already know that it's being packed (e.g., if
2495          * it was included via bitmaps, we would not have parsed it
2496          * previously).
2497          */
2498         if (packlist_find(&to_pack, oid->hash, NULL))
2499                 return;
2500
2501         tag = lookup_tag(the_repository, oid);
2502         while (1) {
2503                 if (!tag || parse_tag(tag) || !tag->tagged)
2504                         die("unable to pack objects reachable from tag %s",
2505                             oid_to_hex(oid));
2506
2507                 add_object_entry(&tag->object.oid, OBJ_TAG, NULL, 0);
2508
2509                 if (tag->tagged->type != OBJ_TAG)
2510                         return;
2511
2512                 tag = (struct tag *)tag->tagged;
2513         }
2514 }
2515
2516 static int add_ref_tag(const char *path, const struct object_id *oid, int flag, void *cb_data)
2517 {
2518         struct object_id peeled;
2519
2520         if (starts_with(path, "refs/tags/") && /* is a tag? */
2521             !peel_ref(path, &peeled)    && /* peelable? */
2522             packlist_find(&to_pack, peeled.hash, NULL))      /* object packed? */
2523                 add_tag_chain(oid);
2524         return 0;
2525 }
2526
2527 static void prepare_pack(int window, int depth)
2528 {
2529         struct object_entry **delta_list;
2530         uint32_t i, nr_deltas;
2531         unsigned n;
2532
2533         if (use_delta_islands)
2534                 resolve_tree_islands(progress, &to_pack);
2535
2536         get_object_details();
2537
2538         /*
2539          * If we're locally repacking then we need to be doubly careful
2540          * from now on in order to make sure no stealth corruption gets
2541          * propagated to the new pack.  Clients receiving streamed packs
2542          * should validate everything they get anyway so no need to incur
2543          * the additional cost here in that case.
2544          */
2545         if (!pack_to_stdout)
2546                 do_check_packed_object_crc = 1;
2547
2548         if (!to_pack.nr_objects || !window || !depth)
2549                 return;
2550
2551         ALLOC_ARRAY(delta_list, to_pack.nr_objects);
2552         nr_deltas = n = 0;
2553
2554         for (i = 0; i < to_pack.nr_objects; i++) {
2555                 struct object_entry *entry = to_pack.objects + i;
2556
2557                 if (DELTA(entry))
2558                         /* This happens if we decided to reuse existing
2559                          * delta from a pack.  "reuse_delta &&" is implied.
2560                          */
2561                         continue;
2562
2563                 if (!entry->type_valid ||
2564                     oe_size_less_than(&to_pack, entry, 50))
2565                         continue;
2566
2567                 if (entry->no_try_delta)
2568                         continue;
2569
2570                 if (!entry->preferred_base) {
2571                         nr_deltas++;
2572                         if (oe_type(entry) < 0)
2573                                 die("unable to get type of object %s",
2574                                     oid_to_hex(&entry->idx.oid));
2575                 } else {
2576                         if (oe_type(entry) < 0) {
2577                                 /*
2578                                  * This object is not found, but we
2579                                  * don't have to include it anyway.
2580                                  */
2581                                 continue;
2582                         }
2583                 }
2584
2585                 delta_list[n++] = entry;
2586         }
2587
2588         if (nr_deltas && n > 1) {
2589                 unsigned nr_done = 0;
2590                 if (progress)
2591                         progress_state = start_progress(_("Compressing objects"),
2592                                                         nr_deltas);
2593                 QSORT(delta_list, n, type_size_sort);
2594                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
2595                 stop_progress(&progress_state);
2596                 if (nr_done != nr_deltas)
2597                         die("inconsistency with delta count");
2598         }
2599         free(delta_list);
2600 }
2601
2602 static int git_pack_config(const char *k, const char *v, void *cb)
2603 {
2604         if (!strcmp(k, "pack.window")) {
2605                 window = git_config_int(k, v);
2606                 return 0;
2607         }
2608         if (!strcmp(k, "pack.windowmemory")) {
2609                 window_memory_limit = git_config_ulong(k, v);
2610                 return 0;
2611         }
2612         if (!strcmp(k, "pack.depth")) {
2613                 depth = git_config_int(k, v);
2614                 return 0;
2615         }
2616         if (!strcmp(k, "pack.deltacachesize")) {
2617                 max_delta_cache_size = git_config_int(k, v);
2618                 return 0;
2619         }
2620         if (!strcmp(k, "pack.deltacachelimit")) {
2621                 cache_max_small_delta_size = git_config_int(k, v);
2622                 return 0;
2623         }
2624         if (!strcmp(k, "pack.writebitmaphashcache")) {
2625                 if (git_config_bool(k, v))
2626                         write_bitmap_options |= BITMAP_OPT_HASH_CACHE;
2627                 else
2628                         write_bitmap_options &= ~BITMAP_OPT_HASH_CACHE;
2629         }
2630         if (!strcmp(k, "pack.usebitmaps")) {
2631                 use_bitmap_index_default = git_config_bool(k, v);
2632                 return 0;
2633         }
2634         if (!strcmp(k, "pack.threads")) {
2635                 delta_search_threads = git_config_int(k, v);
2636                 if (delta_search_threads < 0)
2637                         die("invalid number of threads specified (%d)",
2638                             delta_search_threads);
2639 #ifdef NO_PTHREADS
2640                 if (delta_search_threads != 1) {
2641                         warning("no threads support, ignoring %s", k);
2642                         delta_search_threads = 0;
2643                 }
2644 #endif
2645                 return 0;
2646         }
2647         if (!strcmp(k, "pack.indexversion")) {
2648                 pack_idx_opts.version = git_config_int(k, v);
2649                 if (pack_idx_opts.version > 2)
2650                         die("bad pack.indexversion=%"PRIu32,
2651                             pack_idx_opts.version);
2652                 return 0;
2653         }
2654         return git_default_config(k, v, cb);
2655 }
2656
2657 static void read_object_list_from_stdin(void)
2658 {
2659         char line[GIT_MAX_HEXSZ + 1 + PATH_MAX + 2];
2660         struct object_id oid;
2661         const char *p;
2662
2663         for (;;) {
2664                 if (!fgets(line, sizeof(line), stdin)) {
2665                         if (feof(stdin))
2666                                 break;
2667                         if (!ferror(stdin))
2668                                 die("fgets returned NULL, not EOF, not error!");
2669                         if (errno != EINTR)
2670                                 die_errno("fgets");
2671                         clearerr(stdin);
2672                         continue;
2673                 }
2674                 if (line[0] == '-') {
2675                         if (get_oid_hex(line+1, &oid))
2676                                 die("expected edge object ID, got garbage:\n %s",
2677                                     line);
2678                         add_preferred_base(&oid);
2679                         continue;
2680                 }
2681                 if (parse_oid_hex(line, &oid, &p))
2682                         die("expected object ID, got garbage:\n %s", line);
2683
2684                 add_preferred_base_object(p + 1);
2685                 add_object_entry(&oid, OBJ_NONE, p + 1, 0);
2686         }
2687 }
2688
2689 /* Remember to update object flag allocation in object.h */
2690 #define OBJECT_ADDED (1u<<20)
2691
2692 static void show_commit(struct commit *commit, void *data)
2693 {
2694         add_object_entry(&commit->object.oid, OBJ_COMMIT, NULL, 0);
2695         commit->object.flags |= OBJECT_ADDED;
2696
2697         if (write_bitmap_index)
2698                 index_commit_for_bitmap(commit);
2699
2700         if (use_delta_islands)
2701                 propagate_island_marks(commit);
2702 }
2703
2704 static void show_object(struct object *obj, const char *name, void *data)
2705 {
2706         add_preferred_base_object(name);
2707         add_object_entry(&obj->oid, obj->type, name, 0);
2708         obj->flags |= OBJECT_ADDED;
2709
2710         if (use_delta_islands) {
2711                 const char *p;
2712                 unsigned depth = 0;
2713                 struct object_entry *ent;
2714
2715                 for (p = strchr(name, '/'); p; p = strchr(p + 1, '/'))
2716                         depth++;
2717
2718                 ent = packlist_find(&to_pack, obj->oid.hash, NULL);
2719                 if (ent && depth > oe_tree_depth(&to_pack, ent))
2720                         oe_set_tree_depth(&to_pack, ent, depth);
2721         }
2722 }
2723
2724 static void show_object__ma_allow_any(struct object *obj, const char *name, void *data)
2725 {
2726         assert(arg_missing_action == MA_ALLOW_ANY);
2727
2728         /*
2729          * Quietly ignore ALL missing objects.  This avoids problems with
2730          * staging them now and getting an odd error later.
2731          */
2732         if (!has_object_file(&obj->oid))
2733                 return;
2734
2735         show_object(obj, name, data);
2736 }
2737
2738 static void show_object__ma_allow_promisor(struct object *obj, const char *name, void *data)
2739 {
2740         assert(arg_missing_action == MA_ALLOW_PROMISOR);
2741
2742         /*
2743          * Quietly ignore EXPECTED missing objects.  This avoids problems with
2744          * staging them now and getting an odd error later.
2745          */
2746         if (!has_object_file(&obj->oid) && is_promisor_object(&obj->oid))
2747                 return;
2748
2749         show_object(obj, name, data);
2750 }
2751
2752 static int option_parse_missing_action(const struct option *opt,
2753                                        const char *arg, int unset)
2754 {
2755         assert(arg);
2756         assert(!unset);
2757
2758         if (!strcmp(arg, "error")) {
2759                 arg_missing_action = MA_ERROR;
2760                 fn_show_object = show_object;
2761                 return 0;
2762         }
2763
2764         if (!strcmp(arg, "allow-any")) {
2765                 arg_missing_action = MA_ALLOW_ANY;
2766                 fetch_if_missing = 0;
2767                 fn_show_object = show_object__ma_allow_any;
2768                 return 0;
2769         }
2770
2771         if (!strcmp(arg, "allow-promisor")) {
2772                 arg_missing_action = MA_ALLOW_PROMISOR;
2773                 fetch_if_missing = 0;
2774                 fn_show_object = show_object__ma_allow_promisor;
2775                 return 0;
2776         }
2777
2778         die(_("invalid value for --missing"));
2779         return 0;
2780 }
2781
2782 static void show_edge(struct commit *commit)
2783 {
2784         add_preferred_base(&commit->object.oid);
2785 }
2786
2787 struct in_pack_object {
2788         off_t offset;
2789         struct object *object;
2790 };
2791
2792 struct in_pack {
2793         unsigned int alloc;
2794         unsigned int nr;
2795         struct in_pack_object *array;
2796 };
2797
2798 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
2799 {
2800         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->oid.hash, p);
2801         in_pack->array[in_pack->nr].object = object;
2802         in_pack->nr++;
2803 }
2804
2805 /*
2806  * Compare the objects in the offset order, in order to emulate the
2807  * "git rev-list --objects" output that produced the pack originally.
2808  */
2809 static int ofscmp(const void *a_, const void *b_)
2810 {
2811         struct in_pack_object *a = (struct in_pack_object *)a_;
2812         struct in_pack_object *b = (struct in_pack_object *)b_;
2813
2814         if (a->offset < b->offset)
2815                 return -1;
2816         else if (a->offset > b->offset)
2817                 return 1;
2818         else
2819                 return oidcmp(&a->object->oid, &b->object->oid);
2820 }
2821
2822 static void add_objects_in_unpacked_packs(struct rev_info *revs)
2823 {
2824         struct packed_git *p;
2825         struct in_pack in_pack;
2826         uint32_t i;
2827
2828         memset(&in_pack, 0, sizeof(in_pack));
2829
2830         for (p = get_packed_git(the_repository); p; p = p->next) {
2831                 struct object_id oid;
2832                 struct object *o;
2833
2834                 if (!p->pack_local || p->pack_keep || p->pack_keep_in_core)
2835                         continue;
2836                 if (open_pack_index(p))
2837                         die("cannot open pack index");
2838
2839                 ALLOC_GROW(in_pack.array,
2840                            in_pack.nr + p->num_objects,
2841                            in_pack.alloc);
2842
2843                 for (i = 0; i < p->num_objects; i++) {
2844                         nth_packed_object_oid(&oid, p, i);
2845                         o = lookup_unknown_object(oid.hash);
2846                         if (!(o->flags & OBJECT_ADDED))
2847                                 mark_in_pack_object(o, p, &in_pack);
2848                         o->flags |= OBJECT_ADDED;
2849                 }
2850         }
2851
2852         if (in_pack.nr) {
2853                 QSORT(in_pack.array, in_pack.nr, ofscmp);
2854                 for (i = 0; i < in_pack.nr; i++) {
2855                         struct object *o = in_pack.array[i].object;
2856                         add_object_entry(&o->oid, o->type, "", 0);
2857                 }
2858         }
2859         free(in_pack.array);
2860 }
2861
2862 static int add_loose_object(const struct object_id *oid, const char *path,
2863                             void *data)
2864 {
2865         enum object_type type = oid_object_info(the_repository, oid, NULL);
2866
2867         if (type < 0) {
2868                 warning("loose object at %s could not be examined", path);
2869                 return 0;
2870         }
2871
2872         add_object_entry(oid, type, "", 0);
2873         return 0;
2874 }
2875
2876 /*
2877  * We actually don't even have to worry about reachability here.
2878  * add_object_entry will weed out duplicates, so we just add every
2879  * loose object we find.
2880  */
2881 static void add_unreachable_loose_objects(void)
2882 {
2883         for_each_loose_file_in_objdir(get_object_directory(),
2884                                       add_loose_object,
2885                                       NULL, NULL, NULL);
2886 }
2887
2888 static int has_sha1_pack_kept_or_nonlocal(const struct object_id *oid)
2889 {
2890         static struct packed_git *last_found = (void *)1;
2891         struct packed_git *p;
2892
2893         p = (last_found != (void *)1) ? last_found :
2894                                         get_packed_git(the_repository);
2895
2896         while (p) {
2897                 if ((!p->pack_local || p->pack_keep ||
2898                                 p->pack_keep_in_core) &&
2899                         find_pack_entry_one(oid->hash, p)) {
2900                         last_found = p;
2901                         return 1;
2902                 }
2903                 if (p == last_found)
2904                         p = get_packed_git(the_repository);
2905                 else
2906                         p = p->next;
2907                 if (p == last_found)
2908                         p = p->next;
2909         }
2910         return 0;
2911 }
2912
2913 /*
2914  * Store a list of sha1s that are should not be discarded
2915  * because they are either written too recently, or are
2916  * reachable from another object that was.
2917  *
2918  * This is filled by get_object_list.
2919  */
2920 static struct oid_array recent_objects;
2921
2922 static int loosened_object_can_be_discarded(const struct object_id *oid,
2923                                             timestamp_t mtime)
2924 {
2925         if (!unpack_unreachable_expiration)
2926                 return 0;
2927         if (mtime > unpack_unreachable_expiration)
2928                 return 0;
2929         if (oid_array_lookup(&recent_objects, oid) >= 0)
2930                 return 0;
2931         return 1;
2932 }
2933
2934 static void loosen_unused_packed_objects(struct rev_info *revs)
2935 {
2936         struct packed_git *p;
2937         uint32_t i;
2938         struct object_id oid;
2939
2940         for (p = get_packed_git(the_repository); p; p = p->next) {
2941                 if (!p->pack_local || p->pack_keep || p->pack_keep_in_core)
2942                         continue;
2943
2944                 if (open_pack_index(p))
2945                         die("cannot open pack index");
2946
2947                 for (i = 0; i < p->num_objects; i++) {
2948                         nth_packed_object_oid(&oid, p, i);
2949                         if (!packlist_find(&to_pack, oid.hash, NULL) &&
2950                             !has_sha1_pack_kept_or_nonlocal(&oid) &&
2951                             !loosened_object_can_be_discarded(&oid, p->mtime))
2952                                 if (force_object_loose(&oid, p->mtime))
2953                                         die("unable to force loose object");
2954                 }
2955         }
2956 }
2957
2958 /*
2959  * This tracks any options which pack-reuse code expects to be on, or which a
2960  * reader of the pack might not understand, and which would therefore prevent
2961  * blind reuse of what we have on disk.
2962  */
2963 static int pack_options_allow_reuse(void)
2964 {
2965         return pack_to_stdout &&
2966                allow_ofs_delta &&
2967                !ignore_packed_keep_on_disk &&
2968                !ignore_packed_keep_in_core &&
2969                (!local || !have_non_local_packs) &&
2970                !incremental;
2971 }
2972
2973 static int get_object_list_from_bitmap(struct rev_info *revs)
2974 {
2975         struct bitmap_index *bitmap_git;
2976         if (!(bitmap_git = prepare_bitmap_walk(revs)))
2977                 return -1;
2978
2979         if (pack_options_allow_reuse() &&
2980             !reuse_partial_packfile_from_bitmap(
2981                         bitmap_git,
2982                         &reuse_packfile,
2983                         &reuse_packfile_objects,
2984                         &reuse_packfile_offset)) {
2985                 assert(reuse_packfile_objects);
2986                 nr_result += reuse_packfile_objects;
2987                 display_progress(progress_state, nr_result);
2988         }
2989
2990         traverse_bitmap_commit_list(bitmap_git, &add_object_entry_from_bitmap);
2991         free_bitmap_index(bitmap_git);
2992         return 0;
2993 }
2994
2995 static void record_recent_object(struct object *obj,
2996                                  const char *name,
2997                                  void *data)
2998 {
2999         oid_array_append(&recent_objects, &obj->oid);
3000 }
3001
3002 static void record_recent_commit(struct commit *commit, void *data)
3003 {
3004         oid_array_append(&recent_objects, &commit->object.oid);
3005 }
3006
3007 static void get_object_list(int ac, const char **av)
3008 {
3009         struct rev_info revs;
3010         char line[1000];
3011         int flags = 0;
3012
3013         init_revisions(&revs, NULL);
3014         save_commit_buffer = 0;
3015         setup_revisions(ac, av, &revs, NULL);
3016
3017         /* make sure shallows are read */
3018         is_repository_shallow(the_repository);
3019
3020         while (fgets(line, sizeof(line), stdin) != NULL) {
3021                 int len = strlen(line);
3022                 if (len && line[len - 1] == '\n')
3023                         line[--len] = 0;
3024                 if (!len)
3025                         break;
3026                 if (*line == '-') {
3027                         if (!strcmp(line, "--not")) {
3028                                 flags ^= UNINTERESTING;
3029                                 write_bitmap_index = 0;
3030                                 continue;
3031                         }
3032                         if (starts_with(line, "--shallow ")) {
3033                                 struct object_id oid;
3034                                 if (get_oid_hex(line + 10, &oid))
3035                                         die("not an SHA-1 '%s'", line + 10);
3036                                 register_shallow(the_repository, &oid);
3037                                 use_bitmap_index = 0;
3038                                 continue;
3039                         }
3040                         die("not a rev '%s'", line);
3041                 }
3042                 if (handle_revision_arg(line, &revs, flags, REVARG_CANNOT_BE_FILENAME))
3043                         die("bad revision '%s'", line);
3044         }
3045
3046         if (use_bitmap_index && !get_object_list_from_bitmap(&revs))
3047                 return;
3048
3049         if (use_delta_islands)
3050                 load_delta_islands();
3051
3052         if (prepare_revision_walk(&revs))
3053                 die("revision walk setup failed");
3054         mark_edges_uninteresting(&revs, show_edge);
3055
3056         if (!fn_show_object)
3057                 fn_show_object = show_object;
3058         traverse_commit_list_filtered(&filter_options, &revs,
3059                                       show_commit, fn_show_object, NULL,
3060                                       NULL);
3061
3062         if (unpack_unreachable_expiration) {
3063                 revs.ignore_missing_links = 1;
3064                 if (add_unseen_recent_objects_to_traversal(&revs,
3065                                 unpack_unreachable_expiration))
3066                         die("unable to add recent objects");
3067                 if (prepare_revision_walk(&revs))
3068                         die("revision walk setup failed");
3069                 traverse_commit_list(&revs, record_recent_commit,
3070                                      record_recent_object, NULL);
3071         }
3072
3073         if (keep_unreachable)
3074                 add_objects_in_unpacked_packs(&revs);
3075         if (pack_loose_unreachable)
3076                 add_unreachable_loose_objects();
3077         if (unpack_unreachable)
3078                 loosen_unused_packed_objects(&revs);
3079
3080         oid_array_clear(&recent_objects);
3081 }
3082
3083 static void add_extra_kept_packs(const struct string_list *names)
3084 {
3085         struct packed_git *p;
3086
3087         if (!names->nr)
3088                 return;
3089
3090         for (p = get_packed_git(the_repository); p; p = p->next) {
3091                 const char *name = basename(p->pack_name);
3092                 int i;
3093
3094                 if (!p->pack_local)
3095                         continue;
3096
3097                 for (i = 0; i < names->nr; i++)
3098                         if (!fspathcmp(name, names->items[i].string))
3099                                 break;
3100
3101                 if (i < names->nr) {
3102                         p->pack_keep_in_core = 1;
3103                         ignore_packed_keep_in_core = 1;
3104                         continue;
3105                 }
3106         }
3107 }
3108
3109 static int option_parse_index_version(const struct option *opt,
3110                                       const char *arg, int unset)
3111 {
3112         char *c;
3113         const char *val = arg;
3114         pack_idx_opts.version = strtoul(val, &c, 10);
3115         if (pack_idx_opts.version > 2)
3116                 die(_("unsupported index version %s"), val);
3117         if (*c == ',' && c[1])
3118                 pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
3119         if (*c || pack_idx_opts.off32_limit & 0x80000000)
3120                 die(_("bad index version '%s'"), val);
3121         return 0;
3122 }
3123
3124 static int option_parse_unpack_unreachable(const struct option *opt,
3125                                            const char *arg, int unset)
3126 {
3127         if (unset) {
3128                 unpack_unreachable = 0;
3129                 unpack_unreachable_expiration = 0;
3130         }
3131         else {
3132                 unpack_unreachable = 1;
3133                 if (arg)
3134                         unpack_unreachable_expiration = approxidate(arg);
3135         }
3136         return 0;
3137 }
3138
3139 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
3140 {
3141         int use_internal_rev_list = 0;
3142         int thin = 0;
3143         int shallow = 0;
3144         int all_progress_implied = 0;
3145         struct argv_array rp = ARGV_ARRAY_INIT;
3146         int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
3147         int rev_list_index = 0;
3148         struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
3149         struct option pack_objects_options[] = {
3150                 OPT_SET_INT('q', "quiet", &progress,
3151                             N_("do not show progress meter"), 0),
3152                 OPT_SET_INT(0, "progress", &progress,
3153                             N_("show progress meter"), 1),
3154                 OPT_SET_INT(0, "all-progress", &progress,
3155                             N_("show progress meter during object writing phase"), 2),
3156                 OPT_BOOL(0, "all-progress-implied",
3157                          &all_progress_implied,
3158                          N_("similar to --all-progress when progress meter is shown")),
3159                 { OPTION_CALLBACK, 0, "index-version", NULL, N_("version[,offset]"),
3160                   N_("write the pack index file in the specified idx format version"),
3161                   0, option_parse_index_version },
3162                 OPT_MAGNITUDE(0, "max-pack-size", &pack_size_limit,
3163                               N_("maximum size of each output pack file")),
3164                 OPT_BOOL(0, "local", &local,
3165                          N_("ignore borrowed objects from alternate object store")),
3166                 OPT_BOOL(0, "incremental", &incremental,
3167                          N_("ignore packed objects")),
3168                 OPT_INTEGER(0, "window", &window,
3169                             N_("limit pack window by objects")),
3170                 OPT_MAGNITUDE(0, "window-memory", &window_memory_limit,
3171                               N_("limit pack window by memory in addition to object limit")),
3172                 OPT_INTEGER(0, "depth", &depth,
3173                             N_("maximum length of delta chain allowed in the resulting pack")),
3174                 OPT_BOOL(0, "reuse-delta", &reuse_delta,
3175                          N_("reuse existing deltas")),
3176                 OPT_BOOL(0, "reuse-object", &reuse_object,
3177                          N_("reuse existing objects")),
3178                 OPT_BOOL(0, "delta-base-offset", &allow_ofs_delta,
3179                          N_("use OFS_DELTA objects")),
3180                 OPT_INTEGER(0, "threads", &delta_search_threads,
3181                             N_("use threads when searching for best delta matches")),
3182                 OPT_BOOL(0, "non-empty", &non_empty,
3183                          N_("do not create an empty pack output")),
3184                 OPT_BOOL(0, "revs", &use_internal_rev_list,
3185                          N_("read revision arguments from standard input")),
3186                 OPT_SET_INT_F(0, "unpacked", &rev_list_unpacked,
3187                               N_("limit the objects to those that are not yet packed"),
3188                               1, PARSE_OPT_NONEG),
3189                 OPT_SET_INT_F(0, "all", &rev_list_all,
3190                               N_("include objects reachable from any reference"),
3191                               1, PARSE_OPT_NONEG),
3192                 OPT_SET_INT_F(0, "reflog", &rev_list_reflog,
3193                               N_("include objects referred by reflog entries"),
3194                               1, PARSE_OPT_NONEG),
3195                 OPT_SET_INT_F(0, "indexed-objects", &rev_list_index,
3196                               N_("include objects referred to by the index"),
3197                               1, PARSE_OPT_NONEG),
3198                 OPT_BOOL(0, "stdout", &pack_to_stdout,
3199                          N_("output pack to stdout")),
3200                 OPT_BOOL(0, "include-tag", &include_tag,
3201                          N_("include tag objects that refer to objects to be packed")),
3202                 OPT_BOOL(0, "keep-unreachable", &keep_unreachable,
3203                          N_("keep unreachable objects")),
3204                 OPT_BOOL(0, "pack-loose-unreachable", &pack_loose_unreachable,
3205                          N_("pack loose unreachable objects")),
3206                 { OPTION_CALLBACK, 0, "unpack-unreachable", NULL, N_("time"),
3207                   N_("unpack unreachable objects newer than <time>"),
3208                   PARSE_OPT_OPTARG, option_parse_unpack_unreachable },
3209                 OPT_BOOL(0, "thin", &thin,
3210                          N_("create thin packs")),
3211                 OPT_BOOL(0, "shallow", &shallow,
3212                          N_("create packs suitable for shallow fetches")),
3213                 OPT_BOOL(0, "honor-pack-keep", &ignore_packed_keep_on_disk,
3214                          N_("ignore packs that have companion .keep file")),
3215                 OPT_STRING_LIST(0, "keep-pack", &keep_pack_list, N_("name"),
3216                                 N_("ignore this pack")),
3217                 OPT_INTEGER(0, "compression", &pack_compression_level,
3218                             N_("pack compression level")),
3219                 OPT_SET_INT(0, "keep-true-parents", &grafts_replace_parents,
3220                             N_("do not hide commits by grafts"), 0),
3221                 OPT_BOOL(0, "use-bitmap-index", &use_bitmap_index,
3222                          N_("use a bitmap index if available to speed up counting objects")),
3223                 OPT_BOOL(0, "write-bitmap-index", &write_bitmap_index,
3224                          N_("write a bitmap index together with the pack index")),
3225                 OPT_PARSE_LIST_OBJECTS_FILTER(&filter_options),
3226                 { OPTION_CALLBACK, 0, "missing", NULL, N_("action"),
3227                   N_("handling for missing objects"), PARSE_OPT_NONEG,
3228                   option_parse_missing_action },
3229                 OPT_BOOL(0, "exclude-promisor-objects", &exclude_promisor_objects,
3230                          N_("do not pack objects in promisor packfiles")),
3231                 OPT_BOOL(0, "delta-islands", &use_delta_islands,
3232                          N_("respect islands during delta compression")),
3233                 OPT_END(),
3234         };
3235
3236         if (DFS_NUM_STATES > (1 << OE_DFS_STATE_BITS))
3237                 BUG("too many dfs states, increase OE_DFS_STATE_BITS");
3238
3239         check_replace_refs = 0;
3240
3241         reset_pack_idx_option(&pack_idx_opts);
3242         git_config(git_pack_config, NULL);
3243
3244         progress = isatty(2);
3245         argc = parse_options(argc, argv, prefix, pack_objects_options,
3246                              pack_usage, 0);
3247
3248         if (argc) {
3249                 base_name = argv[0];
3250                 argc--;
3251         }
3252         if (pack_to_stdout != !base_name || argc)
3253                 usage_with_options(pack_usage, pack_objects_options);
3254
3255         if (depth >= (1 << OE_DEPTH_BITS)) {
3256                 warning(_("delta chain depth %d is too deep, forcing %d"),
3257                         depth, (1 << OE_DEPTH_BITS) - 1);
3258                 depth = (1 << OE_DEPTH_BITS) - 1;
3259         }
3260         if (cache_max_small_delta_size >= (1U << OE_Z_DELTA_BITS)) {
3261                 warning(_("pack.deltaCacheLimit is too high, forcing %d"),
3262                         (1U << OE_Z_DELTA_BITS) - 1);
3263                 cache_max_small_delta_size = (1U << OE_Z_DELTA_BITS) - 1;
3264         }
3265
3266         argv_array_push(&rp, "pack-objects");
3267         if (thin) {
3268                 use_internal_rev_list = 1;
3269                 argv_array_push(&rp, shallow
3270                                 ? "--objects-edge-aggressive"
3271                                 : "--objects-edge");
3272         } else
3273                 argv_array_push(&rp, "--objects");
3274
3275         if (rev_list_all) {
3276                 use_internal_rev_list = 1;
3277                 argv_array_push(&rp, "--all");
3278         }
3279         if (rev_list_reflog) {
3280                 use_internal_rev_list = 1;
3281                 argv_array_push(&rp, "--reflog");
3282         }
3283         if (rev_list_index) {
3284                 use_internal_rev_list = 1;
3285                 argv_array_push(&rp, "--indexed-objects");
3286         }
3287         if (rev_list_unpacked) {
3288                 use_internal_rev_list = 1;
3289                 argv_array_push(&rp, "--unpacked");
3290         }
3291
3292         if (exclude_promisor_objects) {
3293                 use_internal_rev_list = 1;
3294                 fetch_if_missing = 0;
3295                 argv_array_push(&rp, "--exclude-promisor-objects");
3296         }
3297         if (unpack_unreachable || keep_unreachable || pack_loose_unreachable)
3298                 use_internal_rev_list = 1;
3299
3300         if (!reuse_object)
3301                 reuse_delta = 0;
3302         if (pack_compression_level == -1)
3303                 pack_compression_level = Z_DEFAULT_COMPRESSION;
3304         else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
3305                 die("bad pack compression level %d", pack_compression_level);
3306
3307         if (!delta_search_threads)      /* --threads=0 means autodetect */
3308                 delta_search_threads = online_cpus();
3309
3310 #ifdef NO_PTHREADS
3311         if (delta_search_threads != 1)
3312                 warning("no threads support, ignoring --threads");
3313 #endif
3314         if (!pack_to_stdout && !pack_size_limit)
3315                 pack_size_limit = pack_size_limit_cfg;
3316         if (pack_to_stdout && pack_size_limit)
3317                 die("--max-pack-size cannot be used to build a pack for transfer.");
3318         if (pack_size_limit && pack_size_limit < 1024*1024) {
3319                 warning("minimum pack size limit is 1 MiB");
3320                 pack_size_limit = 1024*1024;
3321         }
3322
3323         if (!pack_to_stdout && thin)
3324                 die("--thin cannot be used to build an indexable pack.");
3325
3326         if (keep_unreachable && unpack_unreachable)
3327                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
3328         if (!rev_list_all || !rev_list_reflog || !rev_list_index)
3329                 unpack_unreachable_expiration = 0;
3330
3331         if (filter_options.choice) {
3332                 if (!pack_to_stdout)
3333                         die("cannot use --filter without --stdout.");
3334                 use_bitmap_index = 0;
3335         }
3336
3337         /*
3338          * "soft" reasons not to use bitmaps - for on-disk repack by default we want
3339          *
3340          * - to produce good pack (with bitmap index not-yet-packed objects are
3341          *   packed in suboptimal order).
3342          *
3343          * - to use more robust pack-generation codepath (avoiding possible
3344          *   bugs in bitmap code and possible bitmap index corruption).
3345          */
3346         if (!pack_to_stdout)
3347                 use_bitmap_index_default = 0;
3348
3349         if (use_bitmap_index < 0)
3350                 use_bitmap_index = use_bitmap_index_default;
3351
3352         /* "hard" reasons not to use bitmaps; these just won't work at all */
3353         if (!use_internal_rev_list || (!pack_to_stdout && write_bitmap_index) || is_repository_shallow(the_repository))
3354                 use_bitmap_index = 0;
3355
3356         if (pack_to_stdout || !rev_list_all)
3357                 write_bitmap_index = 0;
3358
3359         if (use_delta_islands)
3360                 argv_array_push(&rp, "--topo-order");
3361
3362         if (progress && all_progress_implied)
3363                 progress = 2;
3364
3365         add_extra_kept_packs(&keep_pack_list);
3366         if (ignore_packed_keep_on_disk) {
3367                 struct packed_git *p;
3368                 for (p = get_packed_git(the_repository); p; p = p->next)
3369                         if (p->pack_local && p->pack_keep)
3370                                 break;
3371                 if (!p) /* no keep-able packs found */
3372                         ignore_packed_keep_on_disk = 0;
3373         }
3374         if (local) {
3375                 /*
3376                  * unlike ignore_packed_keep_on_disk above, we do not
3377                  * want to unset "local" based on looking at packs, as
3378                  * it also covers non-local objects
3379                  */
3380                 struct packed_git *p;
3381                 for (p = get_packed_git(the_repository); p; p = p->next) {
3382                         if (!p->pack_local) {
3383                                 have_non_local_packs = 1;
3384                                 break;
3385                         }
3386                 }
3387         }
3388
3389         prepare_packing_data(&to_pack);
3390
3391         if (progress)
3392                 progress_state = start_progress(_("Enumerating objects"), 0);
3393         if (!use_internal_rev_list)
3394                 read_object_list_from_stdin();
3395         else {
3396                 get_object_list(rp.argc, rp.argv);
3397                 argv_array_clear(&rp);
3398         }
3399         cleanup_preferred_base();
3400         if (include_tag && nr_result)
3401                 for_each_ref(add_ref_tag, NULL);
3402         stop_progress(&progress_state);
3403
3404         if (non_empty && !nr_result)
3405                 return 0;
3406         if (nr_result)
3407                 prepare_pack(window, depth);
3408         write_pack_file();
3409         if (progress)
3410                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
3411                         " reused %"PRIu32" (delta %"PRIu32")\n",
3412                         written, written_delta, reused, reused_delta);
3413         return 0;
3414 }