builtin/pack-objects.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "repository.h"
   4 #include "config.h"
   5 #include "attr.h"
   6 #include "object.h"
   7 #include "blob.h"
   8 #include "commit.h"
   9 #include "tag.h"
  10 #include "tree.h"
  11 #include "delta.h"
  12 #include "pack.h"
  13 #include "pack-revindex.h"
  14 #include "csum-file.h"
  15 #include "tree-walk.h"
  16 #include "diff.h"
  17 #include "revision.h"
  18 #include "list-objects.h"
  19 #include "list-objects-filter.h"
  20 #include "list-objects-filter-options.h"
  21 #include "pack-objects.h"
  22 #include "progress.h"
  23 #include "refs.h"
  24 #include "streaming.h"
  25 #include "thread-utils.h"
  26 #include "pack-bitmap.h"
  27 #include "delta-islands.h"
  28 #include "reachable.h"
  29 #include "sha1-array.h"
  30 #include "argv-array.h"
  31 #include "list.h"
  32 #include "packfile.h"
  33 #include "object-store.h"
  34 #include "dir.h"
  35 #include "midx.h"
  36
  37 #define IN_PACK(obj) oe_in_pack(&to_pack, obj)
  38 #define SIZE(obj) oe_size(&to_pack, obj)
  39 #define SET_SIZE(obj,size) oe_set_size(&to_pack, obj, size)
  40 #define DELTA_SIZE(obj) oe_delta_size(&to_pack, obj)
  41 #define DELTA(obj) oe_delta(&to_pack, obj)
  42 #define DELTA_CHILD(obj) oe_delta_child(&to_pack, obj)
  43 #define DELTA_SIBLING(obj) oe_delta_sibling(&to_pack, obj)
  44 #define SET_DELTA(obj, val) oe_set_delta(&to_pack, obj, val)
  45 #define SET_DELTA_EXT(obj, oid) oe_set_delta_ext(&to_pack, obj, oid)
  46 #define SET_DELTA_SIZE(obj, val) oe_set_delta_size(&to_pack, obj, val)
  47 #define SET_DELTA_CHILD(obj, val) oe_set_delta_child(&to_pack, obj, val)
  48 #define SET_DELTA_SIBLING(obj, val) oe_set_delta_sibling(&to_pack, obj, val)
  49
  50 static const char *pack_usage[] = {
  51         N_("git pack-objects --stdout [<options>...] [< <ref-list> | < <object-list>]"),
  52         N_("git pack-objects [<options>...] <base-name> [< <ref-list> | < <object-list>]"),
  53         NULL
  54 };
  55
  56 /*
  57  * Objects we are going to pack are collected in the `to_pack` structure.
  58  * It contains an array (dynamically expanded) of the object data, and a map
  59  * that can resolve SHA1s to their position in the array.
  60  */
  61 static struct packing_data to_pack;
  62
  63 static struct pack_idx_entry **written_list;
  64 static uint32_t nr_result, nr_written, nr_seen;
  65 static struct bitmap_index *bitmap_git;
  66 static uint32_t write_layer;
  67
  68 static int non_empty;
  69 static int reuse_delta = 1, reuse_object = 1;
  70 static int keep_unreachable, unpack_unreachable, include_tag;
  71 static timestamp_t unpack_unreachable_expiration;
  72 static int pack_loose_unreachable;
  73 static int local;
  74 static int have_non_local_packs;
  75 static int incremental;
  76 static int ignore_packed_keep_on_disk;
  77 static int ignore_packed_keep_in_core;
  78 static int allow_ofs_delta;
  79 static struct pack_idx_option pack_idx_opts;
  80 static const char *base_name;
  81 static int progress = 1;
  82 static int window = 10;
  83 static unsigned long pack_size_limit;
  84 static int depth = 50;
  85 static int delta_search_threads;
  86 static int pack_to_stdout;
  87 static int thin;
  88 static int num_preferred_base;
  89 static struct progress *progress_state;
  90
  91 static struct packed_git *reuse_packfile;
  92 static uint32_t reuse_packfile_objects;
  93 static off_t reuse_packfile_offset;
  94
  95 static int use_bitmap_index_default = 1;
  96 static int use_bitmap_index = -1;
  97 static int write_bitmap_index;
  98 static uint16_t write_bitmap_options;
  99
 100 static int exclude_promisor_objects;
 101
 102 static int use_delta_islands;
 103
 104 static unsigned long delta_cache_size = 0;
 105 static unsigned long max_delta_cache_size = DEFAULT_DELTA_CACHE_SIZE;
 106 static unsigned long cache_max_small_delta_size = 1000;
 107
 108 static unsigned long window_memory_limit = 0;
 109
 110 static struct list_objects_filter_options filter_options;
 111
 112 enum missing_action {
 113         MA_ERROR = 0,      /* fail if any missing objects are encountered */
 114         MA_ALLOW_ANY,      /* silently allow ALL missing objects */
 115         MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
 116 };
 117 static enum missing_action arg_missing_action;
 118 static show_object_fn fn_show_object;
 119
 120 /*
 121  * stats
 122  */
 123 static uint32_t written, written_delta;
 124 static uint32_t reused, reused_delta;
 125
 126 /*
 127  * Indexed commits
 128  */
 129 static struct commit **indexed_commits;
 130 static unsigned int indexed_commits_nr;
 131 static unsigned int indexed_commits_alloc;
 132
 133 static void index_commit_for_bitmap(struct commit *commit)
 134 {
 135         if (indexed_commits_nr >= indexed_commits_alloc) {
 136                 indexed_commits_alloc = (indexed_commits_alloc + 32) * 2;
 137                 REALLOC_ARRAY(indexed_commits, indexed_commits_alloc);
 138         }
 139
 140         indexed_commits[indexed_commits_nr++] = commit;
 141 }
 142
 143 static void *get_delta(struct object_entry *entry)
 144 {
 145         unsigned long size, base_size, delta_size;
 146         void *buf, *base_buf, *delta_buf;
 147         enum object_type type;
 148
 149         buf = read_object_file(&entry->idx.oid, &type, &size);
 150         if (!buf)
 151                 die(_("unable to read %s"), oid_to_hex(&entry->idx.oid));
 152         base_buf = read_object_file(&DELTA(entry)->idx.oid, &type,
 153                                     &base_size);
 154         if (!base_buf)
 155                 die("unable to read %s",
 156                     oid_to_hex(&DELTA(entry)->idx.oid));
 157         delta_buf = diff_delta(base_buf, base_size,
 158                                buf, size, &delta_size, 0);
 159         /*
 160          * We succesfully computed this delta once but dropped it for
 161          * memory reasons. Something is very wrong if this time we
 162          * recompute and create a different delta.
 163          */
 164         if (!delta_buf || delta_size != DELTA_SIZE(entry))
 165                 BUG("delta size changed");
 166         free(buf);
 167         free(base_buf);
 168         return delta_buf;
 169 }
 170
 171 static unsigned long do_compress(void **pptr, unsigned long size)
 172 {
 173         git_zstream stream;
 174         void *in, *out;
 175         unsigned long maxsize;
 176
 177         git_deflate_init(&stream, pack_compression_level);
 178         maxsize = git_deflate_bound(&stream, size);
 179
 180         in = *pptr;
 181         out = xmalloc(maxsize);
 182         *pptr = out;
 183
 184         stream.next_in = in;
 185         stream.avail_in = size;
 186         stream.next_out = out;
 187         stream.avail_out = maxsize;
 188         while (git_deflate(&stream, Z_FINISH) == Z_OK)
 189                 ; /* nothing */
 190         git_deflate_end(&stream);
 191
 192         free(in);
 193         return stream.total_out;
 194 }
 195
 196 static unsigned long write_large_blob_data(struct git_istream *st, struct hashfile *f,
 197                                            const struct object_id *oid)
 198 {
 199         git_zstream stream;
 200         unsigned char ibuf[1024 * 16];
 201         unsigned char obuf[1024 * 16];
 202         unsigned long olen = 0;
 203
 204         git_deflate_init(&stream, pack_compression_level);
 205
 206         for (;;) {
 207                 ssize_t readlen;
 208                 int zret = Z_OK;
 209                 readlen = read_istream(st, ibuf, sizeof(ibuf));
 210                 if (readlen == -1)
 211                         die(_("unable to read %s"), oid_to_hex(oid));
 212
 213                 stream.next_in = ibuf;
 214                 stream.avail_in = readlen;
 215                 while ((stream.avail_in || readlen == 0) &&
 216                        (zret == Z_OK || zret == Z_BUF_ERROR)) {
 217                         stream.next_out = obuf;
 218                         stream.avail_out = sizeof(obuf);
 219                         zret = git_deflate(&stream, readlen ? 0 : Z_FINISH);
 220                         hashwrite(f, obuf, stream.next_out - obuf);
 221                         olen += stream.next_out - obuf;
 222                 }
 223                 if (stream.avail_in)
 224                         die(_("deflate error (%d)"), zret);
 225                 if (readlen == 0) {
 226                         if (zret != Z_STREAM_END)
 227                                 die(_("deflate error (%d)"), zret);
 228                         break;
 229                 }
 230         }
 231         git_deflate_end(&stream);
 232         return olen;
 233 }
 234
 235 /*
 236  * we are going to reuse the existing object data as is.  make
 237  * sure it is not corrupt.
 238  */
 239 static int check_pack_inflate(struct packed_git *p,
 240                 struct pack_window **w_curs,
 241                 off_t offset,
 242                 off_t len,
 243                 unsigned long expect)
 244 {
 245         git_zstream stream;
 246         unsigned char fakebuf[4096], *in;
 247         int st;
 248
 249         memset(&stream, 0, sizeof(stream));
 250         git_inflate_init(&stream);
 251         do {
 252                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 253                 stream.next_in = in;
 254                 stream.next_out = fakebuf;
 255                 stream.avail_out = sizeof(fakebuf);
 256                 st = git_inflate(&stream, Z_FINISH);
 257                 offset += stream.next_in - in;
 258         } while (st == Z_OK || st == Z_BUF_ERROR);
 259         git_inflate_end(&stream);
 260         return (st == Z_STREAM_END &&
 261                 stream.total_out == expect &&
 262                 stream.total_in == len) ? 0 : -1;
 263 }
 264
 265 static void copy_pack_data(struct hashfile *f,
 266                 struct packed_git *p,
 267                 struct pack_window **w_curs,
 268                 off_t offset,
 269                 off_t len)
 270 {
 271         unsigned char *in;
 272         unsigned long avail;
 273
 274         while (len) {
 275                 in = use_pack(p, w_curs, offset, &avail);
 276                 if (avail > len)
 277                         avail = (unsigned long)len;
 278                 hashwrite(f, in, avail);
 279                 offset += avail;
 280                 len -= avail;
 281         }
 282 }
 283
 284 /* Return 0 if we will bust the pack-size limit */
 285 static unsigned long write_no_reuse_object(struct hashfile *f, struct object_entry *entry,
 286                                            unsigned long limit, int usable_delta)
 287 {
 288         unsigned long size, datalen;
 289         unsigned char header[MAX_PACK_OBJECT_HEADER],
 290                       dheader[MAX_PACK_OBJECT_HEADER];
 291         unsigned hdrlen;
 292         enum object_type type;
 293         void *buf;
 294         struct git_istream *st = NULL;
 295         const unsigned hashsz = the_hash_algo->rawsz;
 296
 297         if (!usable_delta) {
 298                 if (oe_type(entry) == OBJ_BLOB &&
 299                     oe_size_greater_than(&to_pack, entry, big_file_threshold) &&
 300                     (st = open_istream(&entry->idx.oid, &type, &size, NULL)) != NULL)
 301                         buf = NULL;
 302                 else {
 303                         buf = read_object_file(&entry->idx.oid, &type, &size);
 304                         if (!buf)
 305                                 die(_("unable to read %s"),
 306                                     oid_to_hex(&entry->idx.oid));
 307                 }
 308                 /*
 309                  * make sure no cached delta data remains from a
 310                  * previous attempt before a pack split occurred.
 311                  */
 312                 FREE_AND_NULL(entry->delta_data);
 313                 entry->z_delta_size = 0;
 314         } else if (entry->delta_data) {
 315                 size = DELTA_SIZE(entry);
 316                 buf = entry->delta_data;
 317                 entry->delta_data = NULL;
 318                 type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 319                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 320         } else {
 321                 buf = get_delta(entry);
 322                 size = DELTA_SIZE(entry);
 323                 type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 324                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 325         }
 326
 327         if (st) /* large blob case, just assume we don't compress well */
 328                 datalen = size;
 329         else if (entry->z_delta_size)
 330                 datalen = entry->z_delta_size;
 331         else
 332                 datalen = do_compress(&buf, size);
 333
 334         /*
 335          * The object header is a byte of 'type' followed by zero or
 336          * more bytes of length.
 337          */
 338         hdrlen = encode_in_pack_object_header(header, sizeof(header),
 339                                               type, size);
 340
 341         if (type == OBJ_OFS_DELTA) {
 342                 /*
 343                  * Deltas with relative base contain an additional
 344                  * encoding of the relative offset for the delta
 345                  * base from this object's position in the pack.
 346                  */
 347                 off_t ofs = entry->idx.offset - DELTA(entry)->idx.offset;
 348                 unsigned pos = sizeof(dheader) - 1;
 349                 dheader[pos] = ofs & 127;
 350                 while (ofs >>= 7)
 351                         dheader[--pos] = 128 | (--ofs & 127);
 352                 if (limit && hdrlen + sizeof(dheader) - pos + datalen + hashsz >= limit) {
 353                         if (st)
 354                                 close_istream(st);
 355                         free(buf);
 356                         return 0;
 357                 }
 358                 hashwrite(f, header, hdrlen);
 359                 hashwrite(f, dheader + pos, sizeof(dheader) - pos);
 360                 hdrlen += sizeof(dheader) - pos;
 361         } else if (type == OBJ_REF_DELTA) {
 362                 /*
 363                  * Deltas with a base reference contain
 364                  * additional bytes for the base object ID.
 365                  */
 366                 if (limit && hdrlen + hashsz + datalen + hashsz >= limit) {
 367                         if (st)
 368                                 close_istream(st);
 369                         free(buf);
 370                         return 0;
 371                 }
 372                 hashwrite(f, header, hdrlen);
 373                 hashwrite(f, DELTA(entry)->idx.oid.hash, hashsz);
 374                 hdrlen += hashsz;
 375         } else {
 376                 if (limit && hdrlen + datalen + hashsz >= limit) {
 377                         if (st)
 378                                 close_istream(st);
 379                         free(buf);
 380                         return 0;
 381                 }
 382                 hashwrite(f, header, hdrlen);
 383         }
 384         if (st) {
 385                 datalen = write_large_blob_data(st, f, &entry->idx.oid);
 386                 close_istream(st);
 387         } else {
 388                 hashwrite(f, buf, datalen);
 389                 free(buf);
 390         }
 391
 392         return hdrlen + datalen;
 393 }
 394
 395 /* Return 0 if we will bust the pack-size limit */
 396 static off_t write_reuse_object(struct hashfile *f, struct object_entry *entry,
 397                                 unsigned long limit, int usable_delta)
 398 {
 399         struct packed_git *p = IN_PACK(entry);
 400         struct pack_window *w_curs = NULL;
 401         struct revindex_entry *revidx;
 402         off_t offset;
 403         enum object_type type = oe_type(entry);
 404         off_t datalen;
 405         unsigned char header[MAX_PACK_OBJECT_HEADER],
 406                       dheader[MAX_PACK_OBJECT_HEADER];
 407         unsigned hdrlen;
 408         const unsigned hashsz = the_hash_algo->rawsz;
 409         unsigned long entry_size = SIZE(entry);
 410
 411         if (DELTA(entry))
 412                 type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 413                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 414         hdrlen = encode_in_pack_object_header(header, sizeof(header),
 415                                               type, entry_size);
 416
 417         offset = entry->in_pack_offset;
 418         revidx = find_pack_revindex(p, offset);
 419         datalen = revidx[1].offset - offset;
 420         if (!pack_to_stdout && p->index_version > 1 &&
 421             check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 422                 error(_("bad packed object CRC for %s"),
 423                       oid_to_hex(&entry->idx.oid));
 424                 unuse_pack(&w_curs);
 425                 return write_no_reuse_object(f, entry, limit, usable_delta);
 426         }
 427
 428         offset += entry->in_pack_header_size;
 429         datalen -= entry->in_pack_header_size;
 430
 431         if (!pack_to_stdout && p->index_version == 1 &&
 432             check_pack_inflate(p, &w_curs, offset, datalen, entry_size)) {
 433                 error(_("corrupt packed object for %s"),
 434                       oid_to_hex(&entry->idx.oid));
 435                 unuse_pack(&w_curs);
 436                 return write_no_reuse_object(f, entry, limit, usable_delta);
 437         }
 438
 439         if (type == OBJ_OFS_DELTA) {
 440                 off_t ofs = entry->idx.offset - DELTA(entry)->idx.offset;
 441                 unsigned pos = sizeof(dheader) - 1;
 442                 dheader[pos] = ofs & 127;
 443                 while (ofs >>= 7)
 444                         dheader[--pos] = 128 | (--ofs & 127);
 445                 if (limit && hdrlen + sizeof(dheader) - pos + datalen + hashsz >= limit) {
 446                         unuse_pack(&w_curs);
 447                         return 0;
 448                 }
 449                 hashwrite(f, header, hdrlen);
 450                 hashwrite(f, dheader + pos, sizeof(dheader) - pos);
 451                 hdrlen += sizeof(dheader) - pos;
 452                 reused_delta++;
 453         } else if (type == OBJ_REF_DELTA) {
 454                 if (limit && hdrlen + hashsz + datalen + hashsz >= limit) {
 455                         unuse_pack(&w_curs);
 456                         return 0;
 457                 }
 458                 hashwrite(f, header, hdrlen);
 459                 hashwrite(f, DELTA(entry)->idx.oid.hash, hashsz);
 460                 hdrlen += hashsz;
 461                 reused_delta++;
 462         } else {
 463                 if (limit && hdrlen + datalen + hashsz >= limit) {
 464                         unuse_pack(&w_curs);
 465                         return 0;
 466                 }
 467                 hashwrite(f, header, hdrlen);
 468         }
 469         copy_pack_data(f, p, &w_curs, offset, datalen);
 470         unuse_pack(&w_curs);
 471         reused++;
 472         return hdrlen + datalen;
 473 }
 474
 475 /* Return 0 if we will bust the pack-size limit */
 476 static off_t write_object(struct hashfile *f,
 477                           struct object_entry *entry,
 478                           off_t write_offset)
 479 {
 480         unsigned long limit;
 481         off_t len;
 482         int usable_delta, to_reuse;
 483
 484         if (!pack_to_stdout)
 485                 crc32_begin(f);
 486
 487         /* apply size limit if limited packsize and not first object */
 488         if (!pack_size_limit || !nr_written)
 489                 limit = 0;
 490         else if (pack_size_limit <= write_offset)
 491                 /*
 492                  * the earlier object did not fit the limit; avoid
 493                  * mistaking this with unlimited (i.e. limit = 0).
 494                  */
 495                 limit = 1;
 496         else
 497                 limit = pack_size_limit - write_offset;
 498
 499         if (!DELTA(entry))
 500                 usable_delta = 0;       /* no delta */
 501         else if (!pack_size_limit)
 502                usable_delta = 1;        /* unlimited packfile */
 503         else if (DELTA(entry)->idx.offset == (off_t)-1)
 504                 usable_delta = 0;       /* base was written to another pack */
 505         else if (DELTA(entry)->idx.offset)
 506                 usable_delta = 1;       /* base already exists in this pack */
 507         else
 508                 usable_delta = 0;       /* base could end up in another pack */
 509
 510         if (!reuse_object)
 511                 to_reuse = 0;   /* explicit */
 512         else if (!IN_PACK(entry))
 513                 to_reuse = 0;   /* can't reuse what we don't have */
 514         else if (oe_type(entry) == OBJ_REF_DELTA ||
 515                  oe_type(entry) == OBJ_OFS_DELTA)
 516                                 /* check_object() decided it for us ... */
 517                 to_reuse = usable_delta;
 518                                 /* ... but pack split may override that */
 519         else if (oe_type(entry) != entry->in_pack_type)
 520                 to_reuse = 0;   /* pack has delta which is unusable */
 521         else if (DELTA(entry))
 522                 to_reuse = 0;   /* we want to pack afresh */
 523         else
 524                 to_reuse = 1;   /* we have it in-pack undeltified,
 525                                  * and we do not need to deltify it.
 526                                  */
 527
 528         if (!to_reuse)
 529                 len = write_no_reuse_object(f, entry, limit, usable_delta);
 530         else
 531                 len = write_reuse_object(f, entry, limit, usable_delta);
 532         if (!len)
 533                 return 0;
 534
 535         if (usable_delta)
 536                 written_delta++;
 537         written++;
 538         if (!pack_to_stdout)
 539                 entry->idx.crc32 = crc32_end(f);
 540         return len;
 541 }
 542
 543 enum write_one_status {
 544         WRITE_ONE_SKIP = -1, /* already written */
 545         WRITE_ONE_BREAK = 0, /* writing this will bust the limit; not written */
 546         WRITE_ONE_WRITTEN = 1, /* normal */
 547         WRITE_ONE_RECURSIVE = 2 /* already scheduled to be written */
 548 };
 549
 550 static enum write_one_status write_one(struct hashfile *f,
 551                                        struct object_entry *e,
 552                                        off_t *offset)
 553 {
 554         off_t size;
 555         int recursing;
 556
 557         /*
 558          * we set offset to 1 (which is an impossible value) to mark
 559          * the fact that this object is involved in "write its base
 560          * first before writing a deltified object" recursion.
 561          */
 562         recursing = (e->idx.offset == 1);
 563         if (recursing) {
 564                 warning(_("recursive delta detected for object %s"),
 565                         oid_to_hex(&e->idx.oid));
 566                 return WRITE_ONE_RECURSIVE;
 567         } else if (e->idx.offset || e->preferred_base) {
 568                 /* offset is non zero if object is written already. */
 569                 return WRITE_ONE_SKIP;
 570         }
 571
 572         /* if we are deltified, write out base object first. */
 573         if (DELTA(e)) {
 574                 e->idx.offset = 1; /* now recurse */
 575                 switch (write_one(f, DELTA(e), offset)) {
 576                 case WRITE_ONE_RECURSIVE:
 577                         /* we cannot depend on this one */
 578                         SET_DELTA(e, NULL);
 579                         break;
 580                 default:
 581                         break;
 582                 case WRITE_ONE_BREAK:
 583                         e->idx.offset = recursing;
 584                         return WRITE_ONE_BREAK;
 585                 }
 586         }
 587
 588         e->idx.offset = *offset;
 589         size = write_object(f, e, *offset);
 590         if (!size) {
 591                 e->idx.offset = recursing;
 592                 return WRITE_ONE_BREAK;
 593         }
 594         written_list[nr_written++] = &e->idx;
 595
 596         /* make sure off_t is sufficiently large not to wrap */
 597         if (signed_add_overflows(*offset, size))
 598                 die(_("pack too large for current definition of off_t"));
 599         *offset += size;
 600         return WRITE_ONE_WRITTEN;
 601 }
 602
 603 static int mark_tagged(const char *path, const struct object_id *oid, int flag,
 604                        void *cb_data)
 605 {
 606         struct object_id peeled;
 607         struct object_entry *entry = packlist_find(&to_pack, oid->hash, NULL);
 608
 609         if (entry)
 610                 entry->tagged = 1;
 611         if (!peel_ref(path, &peeled)) {
 612                 entry = packlist_find(&to_pack, peeled.hash, NULL);
 613                 if (entry)
 614                         entry->tagged = 1;
 615         }
 616         return 0;
 617 }
 618
 619 static inline void add_to_write_order(struct object_entry **wo,
 620                                unsigned int *endp,
 621                                struct object_entry *e)
 622 {
 623         if (e->filled || oe_layer(&to_pack, e) != write_layer)
 624                 return;
 625         wo[(*endp)++] = e;
 626         e->filled = 1;
 627 }
 628
 629 static void add_descendants_to_write_order(struct object_entry **wo,
 630                                            unsigned int *endp,
 631                                            struct object_entry *e)
 632 {
 633         int add_to_order = 1;
 634         while (e) {
 635                 if (add_to_order) {
 636                         struct object_entry *s;
 637                         /* add this node... */
 638                         add_to_write_order(wo, endp, e);
 639                         /* all its siblings... */
 640                         for (s = DELTA_SIBLING(e); s; s = DELTA_SIBLING(s)) {
 641                                 add_to_write_order(wo, endp, s);
 642                         }
 643                 }
 644                 /* drop down a level to add left subtree nodes if possible */
 645                 if (DELTA_CHILD(e)) {
 646                         add_to_order = 1;
 647                         e = DELTA_CHILD(e);
 648                 } else {
 649                         add_to_order = 0;
 650                         /* our sibling might have some children, it is next */
 651                         if (DELTA_SIBLING(e)) {
 652                                 e = DELTA_SIBLING(e);
 653                                 continue;
 654                         }
 655                         /* go back to our parent node */
 656                         e = DELTA(e);
 657                         while (e && !DELTA_SIBLING(e)) {
 658                                 /* we're on the right side of a subtree, keep
 659                                  * going up until we can go right again */
 660                                 e = DELTA(e);
 661                         }
 662                         if (!e) {
 663                                 /* done- we hit our original root node */
 664                                 return;
 665                         }
 666                         /* pass it off to sibling at this level */
 667                         e = DELTA_SIBLING(e);
 668                 }
 669         };
 670 }
 671
 672 static void add_family_to_write_order(struct object_entry **wo,
 673                                       unsigned int *endp,
 674                                       struct object_entry *e)
 675 {
 676         struct object_entry *root;
 677
 678         for (root = e; DELTA(root); root = DELTA(root))
 679                 ; /* nothing */
 680         add_descendants_to_write_order(wo, endp, root);
 681 }
 682
 683 static void compute_layer_order(struct object_entry **wo, unsigned int *wo_end)
 684 {
 685         unsigned int i, last_untagged;
 686         struct object_entry *objects = to_pack.objects;
 687
 688         for (i = 0; i < to_pack.nr_objects; i++) {
 689                 if (objects[i].tagged)
 690                         break;
 691                 add_to_write_order(wo, wo_end, &objects[i]);
 692         }
 693         last_untagged = i;
 694
 695         /*
 696          * Then fill all the tagged tips.
 697          */
 698         for (; i < to_pack.nr_objects; i++) {
 699                 if (objects[i].tagged)
 700                         add_to_write_order(wo, wo_end, &objects[i]);
 701         }
 702
 703         /*
 704          * And then all remaining commits and tags.
 705          */
 706         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 707                 if (oe_type(&objects[i]) != OBJ_COMMIT &&
 708                     oe_type(&objects[i]) != OBJ_TAG)
 709                         continue;
 710                 add_to_write_order(wo, wo_end, &objects[i]);
 711         }
 712
 713         /*
 714          * And then all the trees.
 715          */
 716         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 717                 if (oe_type(&objects[i]) != OBJ_TREE)
 718                         continue;
 719                 add_to_write_order(wo, wo_end, &objects[i]);
 720         }
 721
 722         /*
 723          * Finally all the rest in really tight order
 724          */
 725         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 726                 if (!objects[i].filled && oe_layer(&to_pack, &objects[i]) == write_layer)
 727                         add_family_to_write_order(wo, wo_end, &objects[i]);
 728         }
 729 }
 730
 731 static struct object_entry **compute_write_order(void)
 732 {
 733         uint32_t max_layers = 1;
 734         unsigned int i, wo_end;
 735
 736         struct object_entry **wo;
 737         struct object_entry *objects = to_pack.objects;
 738
 739         for (i = 0; i < to_pack.nr_objects; i++) {
 740                 objects[i].tagged = 0;
 741                 objects[i].filled = 0;
 742                 SET_DELTA_CHILD(&objects[i], NULL);
 743                 SET_DELTA_SIBLING(&objects[i], NULL);
 744         }
 745
 746         /*
 747          * Fully connect delta_child/delta_sibling network.
 748          * Make sure delta_sibling is sorted in the original
 749          * recency order.
 750          */
 751         for (i = to_pack.nr_objects; i > 0;) {
 752                 struct object_entry *e = &objects[--i];
 753                 if (!DELTA(e))
 754                         continue;
 755                 /* Mark me as the first child */
 756                 e->delta_sibling_idx = DELTA(e)->delta_child_idx;
 757                 SET_DELTA_CHILD(DELTA(e), e);
 758         }
 759
 760         /*
 761          * Mark objects that are at the tip of tags.
 762          */
 763         for_each_tag_ref(mark_tagged, NULL);
 764
 765         if (use_delta_islands)
 766                 max_layers = compute_pack_layers(&to_pack);
 767
 768         ALLOC_ARRAY(wo, to_pack.nr_objects);
 769         wo_end = 0;
 770
 771         for (; write_layer < max_layers; ++write_layer)
 772                 compute_layer_order(wo, &wo_end);
 773
 774         if (wo_end != to_pack.nr_objects)
 775                 die(_("ordered %u objects, expected %"PRIu32),
 776                     wo_end, to_pack.nr_objects);
 777
 778         return wo;
 779 }
 780
 781 static off_t write_reused_pack(struct hashfile *f)
 782 {
 783         unsigned char buffer[8192];
 784         off_t to_write, total;
 785         int fd;
 786
 787         if (!is_pack_valid(reuse_packfile))
 788                 die(_("packfile is invalid: %s"), reuse_packfile->pack_name);
 789
 790         fd = git_open(reuse_packfile->pack_name);
 791         if (fd < 0)
 792                 die_errno(_("unable to open packfile for reuse: %s"),
 793                           reuse_packfile->pack_name);
 794
 795         if (lseek(fd, sizeof(struct pack_header), SEEK_SET) == -1)
 796                 die_errno(_("unable to seek in reused packfile"));
 797
 798         if (reuse_packfile_offset < 0)
 799                 reuse_packfile_offset = reuse_packfile->pack_size - the_hash_algo->rawsz;
 800
 801         total = to_write = reuse_packfile_offset - sizeof(struct pack_header);
 802
 803         while (to_write) {
 804                 int read_pack = xread(fd, buffer, sizeof(buffer));
 805
 806                 if (read_pack <= 0)
 807                         die_errno(_("unable to read from reused packfile"));
 808
 809                 if (read_pack > to_write)
 810                         read_pack = to_write;
 811
 812                 hashwrite(f, buffer, read_pack);
 813                 to_write -= read_pack;
 814
 815                 /*
 816                  * We don't know the actual number of objects written,
 817                  * only how many bytes written, how many bytes total, and
 818                  * how many objects total. So we can fake it by pretending all
 819                  * objects we are writing are the same size. This gives us a
 820                  * smooth progress meter, and at the end it matches the true
 821                  * answer.
 822                  */
 823                 written = reuse_packfile_objects *
 824                                 (((double)(total - to_write)) / total);
 825                 display_progress(progress_state, written);
 826         }
 827
 828         close(fd);
 829         written = reuse_packfile_objects;
 830         display_progress(progress_state, written);
 831         return reuse_packfile_offset - sizeof(struct pack_header);
 832 }
 833
 834 static const char no_split_warning[] = N_(
 835 "disabling bitmap writing, packs are split due to pack.packSizeLimit"
 836 );
 837
 838 static void write_pack_file(void)
 839 {
 840         uint32_t i = 0, j;
 841         struct hashfile *f;
 842         off_t offset;
 843         uint32_t nr_remaining = nr_result;
 844         time_t last_mtime = 0;
 845         struct object_entry **write_order;
 846
 847         if (progress > pack_to_stdout)
 848                 progress_state = start_progress(_("Writing objects"), nr_result);
 849         ALLOC_ARRAY(written_list, to_pack.nr_objects);
 850         write_order = compute_write_order();
 851
 852         do {
 853                 struct object_id oid;
 854                 char *pack_tmp_name = NULL;
 855
 856                 if (pack_to_stdout)
 857                         f = hashfd_throughput(1, "<stdout>", progress_state);
 858                 else
 859                         f = create_tmp_packfile(&pack_tmp_name);
 860
 861                 offset = write_pack_header(f, nr_remaining);
 862
 863                 if (reuse_packfile) {
 864                         off_t packfile_size;
 865                         assert(pack_to_stdout);
 866
 867                         packfile_size = write_reused_pack(f);
 868                         offset += packfile_size;
 869                 }
 870
 871                 nr_written = 0;
 872                 for (; i < to_pack.nr_objects; i++) {
 873                         struct object_entry *e = write_order[i];
 874                         if (write_one(f, e, &offset) == WRITE_ONE_BREAK)
 875                                 break;
 876                         display_progress(progress_state, written);
 877                 }
 878
 879                 /*
 880                  * Did we write the wrong # entries in the header?
 881                  * If so, rewrite it like in fast-import
 882                  */
 883                 if (pack_to_stdout) {
 884                         finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_CLOSE);
 885                 } else if (nr_written == nr_remaining) {
 886                         finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
 887                 } else {
 888                         int fd = finalize_hashfile(f, oid.hash, 0);
 889                         fixup_pack_header_footer(fd, oid.hash, pack_tmp_name,
 890                                                  nr_written, oid.hash, offset);
 891                         close(fd);
 892                         if (write_bitmap_index) {
 893                                 warning(_(no_split_warning));
 894                                 write_bitmap_index = 0;
 895                         }
 896                 }
 897
 898                 if (!pack_to_stdout) {
 899                         struct stat st;
 900                         struct strbuf tmpname = STRBUF_INIT;
 901
 902                         /*
 903                          * Packs are runtime accessed in their mtime
 904                          * order since newer packs are more likely to contain
 905                          * younger objects.  So if we are creating multiple
 906                          * packs then we should modify the mtime of later ones
 907                          * to preserve this property.
 908                          */
 909                         if (stat(pack_tmp_name, &st) < 0) {
 910                                 warning_errno(_("failed to stat %s"), pack_tmp_name);
 911                         } else if (!last_mtime) {
 912                                 last_mtime = st.st_mtime;
 913                         } else {
 914                                 struct utimbuf utb;
 915                                 utb.actime = st.st_atime;
 916                                 utb.modtime = --last_mtime;
 917                                 if (utime(pack_tmp_name, &utb) < 0)
 918                                         warning_errno(_("failed utime() on %s"), pack_tmp_name);
 919                         }
 920
 921                         strbuf_addf(&tmpname, "%s-", base_name);
 922
 923                         if (write_bitmap_index) {
 924                                 bitmap_writer_set_checksum(oid.hash);
 925                                 bitmap_writer_build_type_index(
 926                                         &to_pack, written_list, nr_written);
 927                         }
 928
 929                         finish_tmp_packfile(&tmpname, pack_tmp_name,
 930                                             written_list, nr_written,
 931                                             &pack_idx_opts, oid.hash);
 932
 933                         if (write_bitmap_index) {
 934                                 strbuf_addf(&tmpname, "%s.bitmap", oid_to_hex(&oid));
 935
 936                                 stop_progress(&progress_state);
 937
 938                                 bitmap_writer_show_progress(progress);
 939                                 bitmap_writer_reuse_bitmaps(&to_pack);
 940                                 bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
 941                                 bitmap_writer_build(&to_pack);
 942                                 bitmap_writer_finish(written_list, nr_written,
 943                                                      tmpname.buf, write_bitmap_options);
 944                                 write_bitmap_index = 0;
 945                         }
 946
 947                         strbuf_release(&tmpname);
 948                         free(pack_tmp_name);
 949                         puts(oid_to_hex(&oid));
 950                 }
 951
 952                 /* mark written objects as written to previous pack */
 953                 for (j = 0; j < nr_written; j++) {
 954                         written_list[j]->offset = (off_t)-1;
 955                 }
 956                 nr_remaining -= nr_written;
 957         } while (nr_remaining && i < to_pack.nr_objects);
 958
 959         free(written_list);
 960         free(write_order);
 961         stop_progress(&progress_state);
 962         if (written != nr_result)
 963                 die(_("wrote %"PRIu32" objects while expecting %"PRIu32),
 964                     written, nr_result);
 965 }
 966
 967 static int no_try_delta(const char *path)
 968 {
 969         static struct attr_check *check;
 970
 971         if (!check)
 972                 check = attr_check_initl("delta", NULL);
 973         git_check_attr(&the_index, path, check);
 974         if (ATTR_FALSE(check->items[0].value))
 975                 return 1;
 976         return 0;
 977 }
 978
 979 /*
 980  * When adding an object, check whether we have already added it
 981  * to our packing list. If so, we can skip. However, if we are
 982  * being asked to excludei t, but the previous mention was to include
 983  * it, make sure to adjust its flags and tweak our numbers accordingly.
 984  *
 985  * As an optimization, we pass out the index position where we would have
 986  * found the item, since that saves us from having to look it up again a
 987  * few lines later when we want to add the new entry.
 988  */
 989 static int have_duplicate_entry(const struct object_id *oid,
 990                                 int exclude,
 991                                 uint32_t *index_pos)
 992 {
 993         struct object_entry *entry;
 994
 995         entry = packlist_find(&to_pack, oid->hash, index_pos);
 996         if (!entry)
 997                 return 0;
 998
 999         if (exclude) {
1000                 if (!entry->preferred_base)
1001                         nr_result--;
1002                 entry->preferred_base = 1;
1003         }
1004
1005         return 1;
1006 }
1007
1008 static int want_found_object(int exclude, struct packed_git *p)
1009 {
1010         if (exclude)
1011                 return 1;
1012         if (incremental)
1013                 return 0;
1014
1015         /*
1016          * When asked to do --local (do not include an object that appears in a
1017          * pack we borrow from elsewhere) or --honor-pack-keep (do not include
1018          * an object that appears in a pack marked with .keep), finding a pack
1019          * that matches the criteria is sufficient for us to decide to omit it.
1020          * However, even if this pack does not satisfy the criteria, we need to
1021          * make sure no copy of this object appears in _any_ pack that makes us
1022          * to omit the object, so we need to check all the packs.
1023          *
1024          * We can however first check whether these options can possible matter;
1025          * if they do not matter we know we want the object in generated pack.
1026          * Otherwise, we signal "-1" at the end to tell the caller that we do
1027          * not know either way, and it needs to check more packs.
1028          */
1029         if (!ignore_packed_keep_on_disk &&
1030             !ignore_packed_keep_in_core &&
1031             (!local || !have_non_local_packs))
1032                 return 1;
1033
1034         if (local && !p->pack_local)
1035                 return 0;
1036         if (p->pack_local &&
1037             ((ignore_packed_keep_on_disk && p->pack_keep) ||
1038              (ignore_packed_keep_in_core && p->pack_keep_in_core)))
1039                 return 0;
1040
1041         /* we don't know yet; keep looking for more packs */
1042         return -1;
1043 }
1044
1045 /*
1046  * Check whether we want the object in the pack (e.g., we do not want
1047  * objects found in non-local stores if the "--local" option was used).
1048  *
1049  * If the caller already knows an existing pack it wants to take the object
1050  * from, that is passed in *found_pack and *found_offset; otherwise this
1051  * function finds if there is any pack that has the object and returns the pack
1052  * and its offset in these variables.
1053  */
1054 static int want_object_in_pack(const struct object_id *oid,
1055                                int exclude,
1056                                struct packed_git **found_pack,
1057                                off_t *found_offset)
1058 {
1059         int want;
1060         struct list_head *pos;
1061         struct multi_pack_index *m;
1062
1063         if (!exclude && local && has_loose_object_nonlocal(oid))
1064                 return 0;
1065
1066         /*
1067          * If we already know the pack object lives in, start checks from that
1068          * pack - in the usual case when neither --local was given nor .keep files
1069          * are present we will determine the answer right now.
1070          */
1071         if (*found_pack) {
1072                 want = want_found_object(exclude, *found_pack);
1073                 if (want != -1)
1074                         return want;
1075         }
1076
1077         for (m = get_multi_pack_index(the_repository); m; m = m->next) {
1078                 struct pack_entry e;
1079                 if (fill_midx_entry(oid, &e, m)) {
1080                         struct packed_git *p = e.p;
1081                         off_t offset;
1082
1083                         if (p == *found_pack)
1084                                 offset = *found_offset;
1085                         else
1086                                 offset = find_pack_entry_one(oid->hash, p);
1087
1088                         if (offset) {
1089                                 if (!*found_pack) {
1090                                         if (!is_pack_valid(p))
1091                                                 continue;
1092                                         *found_offset = offset;
1093                                         *found_pack = p;
1094                                 }
1095                                 want = want_found_object(exclude, p);
1096                                 if (want != -1)
1097                                         return want;
1098                         }
1099                 }
1100         }
1101
1102         list_for_each(pos, get_packed_git_mru(the_repository)) {
1103                 struct packed_git *p = list_entry(pos, struct packed_git, mru);
1104                 off_t offset;
1105
1106                 if (p == *found_pack)
1107                         offset = *found_offset;
1108                 else
1109                         offset = find_pack_entry_one(oid->hash, p);
1110
1111                 if (offset) {
1112                         if (!*found_pack) {
1113                                 if (!is_pack_valid(p))
1114                                         continue;
1115                                 *found_offset = offset;
1116                                 *found_pack = p;
1117                         }
1118                         want = want_found_object(exclude, p);
1119                         if (!exclude && want > 0)
1120                                 list_move(&p->mru,
1121                                           get_packed_git_mru(the_repository));
1122                         if (want != -1)
1123                                 return want;
1124                 }
1125         }
1126
1127         return 1;
1128 }
1129
1130 static void create_object_entry(const struct object_id *oid,
1131                                 enum object_type type,
1132                                 uint32_t hash,
1133                                 int exclude,
1134                                 int no_try_delta,
1135                                 uint32_t index_pos,
1136                                 struct packed_git *found_pack,
1137                                 off_t found_offset)
1138 {
1139         struct object_entry *entry;
1140
1141         entry = packlist_alloc(&to_pack, oid->hash, index_pos);
1142         entry->hash = hash;
1143         oe_set_type(entry, type);
1144         if (exclude)
1145                 entry->preferred_base = 1;
1146         else
1147                 nr_result++;
1148         if (found_pack) {
1149                 oe_set_in_pack(&to_pack, entry, found_pack);
1150                 entry->in_pack_offset = found_offset;
1151         }
1152
1153         entry->no_try_delta = no_try_delta;
1154 }
1155
1156 static const char no_closure_warning[] = N_(
1157 "disabling bitmap writing, as some objects are not being packed"
1158 );
1159
1160 static int add_object_entry(const struct object_id *oid, enum object_type type,
1161                             const char *name, int exclude)
1162 {
1163         struct packed_git *found_pack = NULL;
1164         off_t found_offset = 0;
1165         uint32_t index_pos;
1166
1167         display_progress(progress_state, ++nr_seen);
1168
1169         if (have_duplicate_entry(oid, exclude, &index_pos))
1170                 return 0;
1171
1172         if (!want_object_in_pack(oid, exclude, &found_pack, &found_offset)) {
1173                 /* The pack is missing an object, so it will not have closure */
1174                 if (write_bitmap_index) {
1175                         warning(_(no_closure_warning));
1176                         write_bitmap_index = 0;
1177                 }
1178                 return 0;
1179         }
1180
1181         create_object_entry(oid, type, pack_name_hash(name),
1182                             exclude, name && no_try_delta(name),
1183                             index_pos, found_pack, found_offset);
1184         return 1;
1185 }
1186
1187 static int add_object_entry_from_bitmap(const struct object_id *oid,
1188                                         enum object_type type,
1189                                         int flags, uint32_t name_hash,
1190                                         struct packed_git *pack, off_t offset)
1191 {
1192         uint32_t index_pos;
1193
1194         display_progress(progress_state, ++nr_seen);
1195
1196         if (have_duplicate_entry(oid, 0, &index_pos))
1197                 return 0;
1198
1199         if (!want_object_in_pack(oid, 0, &pack, &offset))
1200                 return 0;
1201
1202         create_object_entry(oid, type, name_hash, 0, 0, index_pos, pack, offset);
1203         return 1;
1204 }
1205
1206 struct pbase_tree_cache {
1207         struct object_id oid;
1208         int ref;
1209         int temporary;
1210         void *tree_data;
1211         unsigned long tree_size;
1212 };
1213
1214 static struct pbase_tree_cache *(pbase_tree_cache[256]);
1215 static int pbase_tree_cache_ix(const struct object_id *oid)
1216 {
1217         return oid->hash[0] % ARRAY_SIZE(pbase_tree_cache);
1218 }
1219 static int pbase_tree_cache_ix_incr(int ix)
1220 {
1221         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
1222 }
1223
1224 static struct pbase_tree {
1225         struct pbase_tree *next;
1226         /* This is a phony "cache" entry; we are not
1227          * going to evict it or find it through _get()
1228          * mechanism -- this is for the toplevel node that
1229          * would almost always change with any commit.
1230          */
1231         struct pbase_tree_cache pcache;
1232 } *pbase_tree;
1233
1234 static struct pbase_tree_cache *pbase_tree_get(const struct object_id *oid)
1235 {
1236         struct pbase_tree_cache *ent, *nent;
1237         void *data;
1238         unsigned long size;
1239         enum object_type type;
1240         int neigh;
1241         int my_ix = pbase_tree_cache_ix(oid);
1242         int available_ix = -1;
1243
1244         /* pbase-tree-cache acts as a limited hashtable.
1245          * your object will be found at your index or within a few
1246          * slots after that slot if it is cached.
1247          */
1248         for (neigh = 0; neigh < 8; neigh++) {
1249                 ent = pbase_tree_cache[my_ix];
1250                 if (ent && oideq(&ent->oid, oid)) {
1251                         ent->ref++;
1252                         return ent;
1253                 }
1254                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
1255                          ((0 <= available_ix) &&
1256                           (!ent && pbase_tree_cache[available_ix])))
1257                         available_ix = my_ix;
1258                 if (!ent)
1259                         break;
1260                 my_ix = pbase_tree_cache_ix_incr(my_ix);
1261         }
1262
1263         /* Did not find one.  Either we got a bogus request or
1264          * we need to read and perhaps cache.
1265          */
1266         data = read_object_file(oid, &type, &size);
1267         if (!data)
1268                 return NULL;
1269         if (type != OBJ_TREE) {
1270                 free(data);
1271                 return NULL;
1272         }
1273
1274         /* We need to either cache or return a throwaway copy */
1275
1276         if (available_ix < 0)
1277                 ent = NULL;
1278         else {
1279                 ent = pbase_tree_cache[available_ix];
1280                 my_ix = available_ix;
1281         }
1282
1283         if (!ent) {
1284                 nent = xmalloc(sizeof(*nent));
1285                 nent->temporary = (available_ix < 0);
1286         }
1287         else {
1288                 /* evict and reuse */
1289                 free(ent->tree_data);
1290                 nent = ent;
1291         }
1292         oidcpy(&nent->oid, oid);
1293         nent->tree_data = data;
1294         nent->tree_size = size;
1295         nent->ref = 1;
1296         if (!nent->temporary)
1297                 pbase_tree_cache[my_ix] = nent;
1298         return nent;
1299 }
1300
1301 static void pbase_tree_put(struct pbase_tree_cache *cache)
1302 {
1303         if (!cache->temporary) {
1304                 cache->ref--;
1305                 return;
1306         }
1307         free(cache->tree_data);
1308         free(cache);
1309 }
1310
1311 static int name_cmp_len(const char *name)
1312 {
1313         int i;
1314         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
1315                 ;
1316         return i;
1317 }
1318
1319 static void add_pbase_object(struct tree_desc *tree,
1320                              const char *name,
1321                              int cmplen,
1322                              const char *fullname)
1323 {
1324         struct name_entry entry;
1325         int cmp;
1326
1327         while (tree_entry(tree,&entry)) {
1328                 if (S_ISGITLINK(entry.mode))
1329                         continue;
1330                 cmp = tree_entry_len(&entry) != cmplen ? 1 :
1331                       memcmp(name, entry.path, cmplen);
1332                 if (cmp > 0)
1333                         continue;
1334                 if (cmp < 0)
1335                         return;
1336                 if (name[cmplen] != '/') {
1337                         add_object_entry(entry.oid,
1338                                          object_type(entry.mode),
1339                                          fullname, 1);
1340                         return;
1341                 }
1342                 if (S_ISDIR(entry.mode)) {
1343                         struct tree_desc sub;
1344                         struct pbase_tree_cache *tree;
1345                         const char *down = name+cmplen+1;
1346                         int downlen = name_cmp_len(down);
1347
1348                         tree = pbase_tree_get(entry.oid);
1349                         if (!tree)
1350                                 return;
1351                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1352
1353                         add_pbase_object(&sub, down, downlen, fullname);
1354                         pbase_tree_put(tree);
1355                 }
1356         }
1357 }
1358
1359 static unsigned *done_pbase_paths;
1360 static int done_pbase_paths_num;
1361 static int done_pbase_paths_alloc;
1362 static int done_pbase_path_pos(unsigned hash)
1363 {
1364         int lo = 0;
1365         int hi = done_pbase_paths_num;
1366         while (lo < hi) {
1367                 int mi = lo + (hi - lo) / 2;
1368                 if (done_pbase_paths[mi] == hash)
1369                         return mi;
1370                 if (done_pbase_paths[mi] < hash)
1371                         hi = mi;
1372                 else
1373                         lo = mi + 1;
1374         }
1375         return -lo-1;
1376 }
1377
1378 static int check_pbase_path(unsigned hash)
1379 {
1380         int pos = done_pbase_path_pos(hash);
1381         if (0 <= pos)
1382                 return 1;
1383         pos = -pos - 1;
1384         ALLOC_GROW(done_pbase_paths,
1385                    done_pbase_paths_num + 1,
1386                    done_pbase_paths_alloc);
1387         done_pbase_paths_num++;
1388         if (pos < done_pbase_paths_num)
1389                 MOVE_ARRAY(done_pbase_paths + pos + 1, done_pbase_paths + pos,
1390                            done_pbase_paths_num - pos - 1);
1391         done_pbase_paths[pos] = hash;
1392         return 0;
1393 }
1394
1395 static void add_preferred_base_object(const char *name)
1396 {
1397         struct pbase_tree *it;
1398         int cmplen;
1399         unsigned hash = pack_name_hash(name);
1400
1401         if (!num_preferred_base || check_pbase_path(hash))
1402                 return;
1403
1404         cmplen = name_cmp_len(name);
1405         for (it = pbase_tree; it; it = it->next) {
1406                 if (cmplen == 0) {
1407                         add_object_entry(&it->pcache.oid, OBJ_TREE, NULL, 1);
1408                 }
1409                 else {
1410                         struct tree_desc tree;
1411                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1412                         add_pbase_object(&tree, name, cmplen, name);
1413                 }
1414         }
1415 }
1416
1417 static void add_preferred_base(struct object_id *oid)
1418 {
1419         struct pbase_tree *it;
1420         void *data;
1421         unsigned long size;
1422         struct object_id tree_oid;
1423
1424         if (window <= num_preferred_base++)
1425                 return;
1426
1427         data = read_object_with_reference(oid, tree_type, &size, &tree_oid);
1428         if (!data)
1429                 return;
1430
1431         for (it = pbase_tree; it; it = it->next) {
1432                 if (oideq(&it->pcache.oid, &tree_oid)) {
1433                         free(data);
1434                         return;
1435                 }
1436         }
1437
1438         it = xcalloc(1, sizeof(*it));
1439         it->next = pbase_tree;
1440         pbase_tree = it;
1441
1442         oidcpy(&it->pcache.oid, &tree_oid);
1443         it->pcache.tree_data = data;
1444         it->pcache.tree_size = size;
1445 }
1446
1447 static void cleanup_preferred_base(void)
1448 {
1449         struct pbase_tree *it;
1450         unsigned i;
1451
1452         it = pbase_tree;
1453         pbase_tree = NULL;
1454         while (it) {
1455                 struct pbase_tree *tmp = it;
1456                 it = tmp->next;
1457                 free(tmp->pcache.tree_data);
1458                 free(tmp);
1459         }
1460
1461         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1462                 if (!pbase_tree_cache[i])
1463                         continue;
1464                 free(pbase_tree_cache[i]->tree_data);
1465                 FREE_AND_NULL(pbase_tree_cache[i]);
1466         }
1467
1468         FREE_AND_NULL(done_pbase_paths);
1469         done_pbase_paths_num = done_pbase_paths_alloc = 0;
1470 }
1471
1472 /*
1473  * Return 1 iff the object specified by "delta" can be sent
1474  * literally as a delta against the base in "base_sha1". If
1475  * so, then *base_out will point to the entry in our packing
1476  * list, or NULL if we must use the external-base list.
1477  *
1478  * Depth value does not matter - find_deltas() will
1479  * never consider reused delta as the base object to
1480  * deltify other objects against, in order to avoid
1481  * circular deltas.
1482  */
1483 static int can_reuse_delta(const unsigned char *base_sha1,
1484                            struct object_entry *delta,
1485                            struct object_entry **base_out)
1486 {
1487         struct object_entry *base;
1488
1489         if (!base_sha1)
1490                 return 0;
1491
1492         /*
1493          * First see if we're already sending the base (or it's explicitly in
1494          * our "excluded" list).
1495          */
1496         base = packlist_find(&to_pack, base_sha1, NULL);
1497         if (base) {
1498                 if (!in_same_island(&delta->idx.oid, &base->idx.oid))
1499                         return 0;
1500                 *base_out = base;
1501                 return 1;
1502         }
1503
1504         /*
1505          * Otherwise, reachability bitmaps may tell us if the receiver has it,
1506          * even if it was buried too deep in history to make it into the
1507          * packing list.
1508          */
1509         if (thin && bitmap_has_sha1_in_uninteresting(bitmap_git, base_sha1)) {
1510                 if (use_delta_islands) {
1511                         struct object_id base_oid;
1512                         hashcpy(base_oid.hash, base_sha1);
1513                         if (!in_same_island(&delta->idx.oid, &base_oid))
1514                                 return 0;
1515                 }
1516                 *base_out = NULL;
1517                 return 1;
1518         }
1519
1520         return 0;
1521 }
1522
1523 static void check_object(struct object_entry *entry)
1524 {
1525         unsigned long canonical_size;
1526
1527         if (IN_PACK(entry)) {
1528                 struct packed_git *p = IN_PACK(entry);
1529                 struct pack_window *w_curs = NULL;
1530                 const unsigned char *base_ref = NULL;
1531                 struct object_entry *base_entry;
1532                 unsigned long used, used_0;
1533                 unsigned long avail;
1534                 off_t ofs;
1535                 unsigned char *buf, c;
1536                 enum object_type type;
1537                 unsigned long in_pack_size;
1538
1539                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1540
1541                 /*
1542                  * We want in_pack_type even if we do not reuse delta
1543                  * since non-delta representations could still be reused.
1544                  */
1545                 used = unpack_object_header_buffer(buf, avail,
1546                                                    &type,
1547                                                    &in_pack_size);
1548                 if (used == 0)
1549                         goto give_up;
1550
1551                 if (type < 0)
1552                         BUG("invalid type %d", type);
1553                 entry->in_pack_type = type;
1554
1555                 /*
1556                  * Determine if this is a delta and if so whether we can
1557                  * reuse it or not.  Otherwise let's find out as cheaply as
1558                  * possible what the actual type and size for this object is.
1559                  */
1560                 switch (entry->in_pack_type) {
1561                 default:
1562                         /* Not a delta hence we've already got all we need. */
1563                         oe_set_type(entry, entry->in_pack_type);
1564                         SET_SIZE(entry, in_pack_size);
1565                         entry->in_pack_header_size = used;
1566                         if (oe_type(entry) < OBJ_COMMIT || oe_type(entry) > OBJ_BLOB)
1567                                 goto give_up;
1568                         unuse_pack(&w_curs);
1569                         return;
1570                 case OBJ_REF_DELTA:
1571                         if (reuse_delta && !entry->preferred_base)
1572                                 base_ref = use_pack(p, &w_curs,
1573                                                 entry->in_pack_offset + used, NULL);
1574                         entry->in_pack_header_size = used + the_hash_algo->rawsz;
1575                         break;
1576                 case OBJ_OFS_DELTA:
1577                         buf = use_pack(p, &w_curs,
1578                                        entry->in_pack_offset + used, NULL);
1579                         used_0 = 0;
1580                         c = buf[used_0++];
1581                         ofs = c & 127;
1582                         while (c & 128) {
1583                                 ofs += 1;
1584                                 if (!ofs || MSB(ofs, 7)) {
1585                                         error(_("delta base offset overflow in pack for %s"),
1586                                               oid_to_hex(&entry->idx.oid));
1587                                         goto give_up;
1588                                 }
1589                                 c = buf[used_0++];
1590                                 ofs = (ofs << 7) + (c & 127);
1591                         }
1592                         ofs = entry->in_pack_offset - ofs;
1593                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1594                                 error(_("delta base offset out of bound for %s"),
1595                                       oid_to_hex(&entry->idx.oid));
1596                                 goto give_up;
1597                         }
1598                         if (reuse_delta && !entry->preferred_base) {
1599                                 struct revindex_entry *revidx;
1600                                 revidx = find_pack_revindex(p, ofs);
1601                                 if (!revidx)
1602                                         goto give_up;
1603                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1604                         }
1605                         entry->in_pack_header_size = used + used_0;
1606                         break;
1607                 }
1608
1609                 if (can_reuse_delta(base_ref, entry, &base_entry)) {
1610                         oe_set_type(entry, entry->in_pack_type);
1611                         SET_SIZE(entry, in_pack_size); /* delta size */
1612                         SET_DELTA_SIZE(entry, in_pack_size);
1613
1614                         if (base_entry) {
1615                                 SET_DELTA(entry, base_entry);
1616                                 entry->delta_sibling_idx = base_entry->delta_child_idx;
1617                                 SET_DELTA_CHILD(base_entry, entry);
1618                         } else {
1619                                 SET_DELTA_EXT(entry, base_ref);
1620                         }
1621
1622                         unuse_pack(&w_curs);
1623                         return;
1624                 }
1625
1626                 if (oe_type(entry)) {
1627                         off_t delta_pos;
1628
1629                         /*
1630                          * This must be a delta and we already know what the
1631                          * final object type is.  Let's extract the actual
1632                          * object size from the delta header.
1633                          */
1634                         delta_pos = entry->in_pack_offset + entry->in_pack_header_size;
1635                         canonical_size = get_size_from_delta(p, &w_curs, delta_pos);
1636                         if (canonical_size == 0)
1637                                 goto give_up;
1638                         SET_SIZE(entry, canonical_size);
1639                         unuse_pack(&w_curs);
1640                         return;
1641                 }
1642
1643                 /*
1644                  * No choice but to fall back to the recursive delta walk
1645                  * with sha1_object_info() to find about the object type
1646                  * at this point...
1647                  */
1648                 give_up:
1649                 unuse_pack(&w_curs);
1650         }
1651
1652         oe_set_type(entry,
1653                     oid_object_info(the_repository, &entry->idx.oid, &canonical_size));
1654         if (entry->type_valid) {
1655                 SET_SIZE(entry, canonical_size);
1656         } else {
1657                 /*
1658                  * Bad object type is checked in prepare_pack().  This is
1659                  * to permit a missing preferred base object to be ignored
1660                  * as a preferred base.  Doing so can result in a larger
1661                  * pack file, but the transfer will still take place.
1662                  */
1663         }
1664 }
1665
1666 static int pack_offset_sort(const void *_a, const void *_b)
1667 {
1668         const struct object_entry *a = *(struct object_entry **)_a;
1669         const struct object_entry *b = *(struct object_entry **)_b;
1670         const struct packed_git *a_in_pack = IN_PACK(a);
1671         const struct packed_git *b_in_pack = IN_PACK(b);
1672
1673         /* avoid filesystem trashing with loose objects */
1674         if (!a_in_pack && !b_in_pack)
1675                 return oidcmp(&a->idx.oid, &b->idx.oid);
1676
1677         if (a_in_pack < b_in_pack)
1678                 return -1;
1679         if (a_in_pack > b_in_pack)
1680                 return 1;
1681         return a->in_pack_offset < b->in_pack_offset ? -1 :
1682                         (a->in_pack_offset > b->in_pack_offset);
1683 }
1684
1685 /*
1686  * Drop an on-disk delta we were planning to reuse. Naively, this would
1687  * just involve blanking out the "delta" field, but we have to deal
1688  * with some extra book-keeping:
1689  *
1690  *   1. Removing ourselves from the delta_sibling linked list.
1691  *
1692  *   2. Updating our size/type to the non-delta representation. These were
1693  *      either not recorded initially (size) or overwritten with the delta type
1694  *      (type) when check_object() decided to reuse the delta.
1695  *
1696  *   3. Resetting our delta depth, as we are now a base object.
1697  */
1698 static void drop_reused_delta(struct object_entry *entry)
1699 {
1700         unsigned *idx = &to_pack.objects[entry->delta_idx - 1].delta_child_idx;
1701         struct object_info oi = OBJECT_INFO_INIT;
1702         enum object_type type;
1703         unsigned long size;
1704
1705         while (*idx) {
1706                 struct object_entry *oe = &to_pack.objects[*idx - 1];
1707
1708                 if (oe == entry)
1709                         *idx = oe->delta_sibling_idx;
1710                 else
1711                         idx = &oe->delta_sibling_idx;
1712         }
1713         SET_DELTA(entry, NULL);
1714         entry->depth = 0;
1715
1716         oi.sizep = &size;
1717         oi.typep = &type;
1718         if (packed_object_info(the_repository, IN_PACK(entry), entry->in_pack_offset, &oi) < 0) {
1719                 /*
1720                  * We failed to get the info from this pack for some reason;
1721                  * fall back to sha1_object_info, which may find another copy.
1722                  * And if that fails, the error will be recorded in oe_type(entry)
1723                  * and dealt with in prepare_pack().
1724                  */
1725                 oe_set_type(entry,
1726                             oid_object_info(the_repository, &entry->idx.oid, &size));
1727         } else {
1728                 oe_set_type(entry, type);
1729         }
1730         SET_SIZE(entry, size);
1731 }
1732
1733 /*
1734  * Follow the chain of deltas from this entry onward, throwing away any links
1735  * that cause us to hit a cycle (as determined by the DFS state flags in
1736  * the entries).
1737  *
1738  * We also detect too-long reused chains that would violate our --depth
1739  * limit.
1740  */
1741 static void break_delta_chains(struct object_entry *entry)
1742 {
1743         /*
1744          * The actual depth of each object we will write is stored as an int,
1745          * as it cannot exceed our int "depth" limit. But before we break
1746          * changes based no that limit, we may potentially go as deep as the
1747          * number of objects, which is elsewhere bounded to a uint32_t.
1748          */
1749         uint32_t total_depth;
1750         struct object_entry *cur, *next;
1751
1752         for (cur = entry, total_depth = 0;
1753              cur;
1754              cur = DELTA(cur), total_depth++) {
1755                 if (cur->dfs_state == DFS_DONE) {
1756                         /*
1757                          * We've already seen this object and know it isn't
1758                          * part of a cycle. We do need to append its depth
1759                          * to our count.
1760                          */
1761                         total_depth += cur->depth;
1762                         break;
1763                 }
1764
1765                 /*
1766                  * We break cycles before looping, so an ACTIVE state (or any
1767                  * other cruft which made its way into the state variable)
1768                  * is a bug.
1769                  */
1770                 if (cur->dfs_state != DFS_NONE)
1771                         BUG("confusing delta dfs state in first pass: %d",
1772                             cur->dfs_state);
1773
1774                 /*
1775                  * Now we know this is the first time we've seen the object. If
1776                  * it's not a delta, we're done traversing, but we'll mark it
1777                  * done to save time on future traversals.
1778                  */
1779                 if (!DELTA(cur)) {
1780                         cur->dfs_state = DFS_DONE;
1781                         break;
1782                 }
1783
1784                 /*
1785                  * Mark ourselves as active and see if the next step causes
1786                  * us to cycle to another active object. It's important to do
1787                  * this _before_ we loop, because it impacts where we make the
1788                  * cut, and thus how our total_depth counter works.
1789                  * E.g., We may see a partial loop like:
1790                  *
1791                  *   A -> B -> C -> D -> B
1792                  *
1793                  * Cutting B->C breaks the cycle. But now the depth of A is
1794                  * only 1, and our total_depth counter is at 3. The size of the
1795                  * error is always one less than the size of the cycle we
1796                  * broke. Commits C and D were "lost" from A's chain.
1797                  *
1798                  * If we instead cut D->B, then the depth of A is correct at 3.
1799                  * We keep all commits in the chain that we examined.
1800                  */
1801                 cur->dfs_state = DFS_ACTIVE;
1802                 if (DELTA(cur)->dfs_state == DFS_ACTIVE) {
1803                         drop_reused_delta(cur);
1804                         cur->dfs_state = DFS_DONE;
1805                         break;
1806                 }
1807         }
1808
1809         /*
1810          * And now that we've gone all the way to the bottom of the chain, we
1811          * need to clear the active flags and set the depth fields as
1812          * appropriate. Unlike the loop above, which can quit when it drops a
1813          * delta, we need to keep going to look for more depth cuts. So we need
1814          * an extra "next" pointer to keep going after we reset cur->delta.
1815          */
1816         for (cur = entry; cur; cur = next) {
1817                 next = DELTA(cur);
1818
1819                 /*
1820                  * We should have a chain of zero or more ACTIVE states down to
1821                  * a final DONE. We can quit after the DONE, because either it
1822                  * has no bases, or we've already handled them in a previous
1823                  * call.
1824                  */
1825                 if (cur->dfs_state == DFS_DONE)
1826                         break;
1827                 else if (cur->dfs_state != DFS_ACTIVE)
1828                         BUG("confusing delta dfs state in second pass: %d",
1829                             cur->dfs_state);
1830
1831                 /*
1832                  * If the total_depth is more than depth, then we need to snip
1833                  * the chain into two or more smaller chains that don't exceed
1834                  * the maximum depth. Most of the resulting chains will contain
1835                  * (depth + 1) entries (i.e., depth deltas plus one base), and
1836                  * the last chain (i.e., the one containing entry) will contain
1837                  * whatever entries are left over, namely
1838                  * (total_depth % (depth + 1)) of them.
1839                  *
1840                  * Since we are iterating towards decreasing depth, we need to
1841                  * decrement total_depth as we go, and we need to write to the
1842                  * entry what its final depth will be after all of the
1843                  * snipping. Since we're snipping into chains of length (depth
1844                  * + 1) entries, the final depth of an entry will be its
1845                  * original depth modulo (depth + 1). Any time we encounter an
1846                  * entry whose final depth is supposed to be zero, we snip it
1847                  * from its delta base, thereby making it so.
1848                  */
1849                 cur->depth = (total_depth--) % (depth + 1);
1850                 if (!cur->depth)
1851                         drop_reused_delta(cur);
1852
1853                 cur->dfs_state = DFS_DONE;
1854         }
1855 }
1856
1857 static void get_object_details(void)
1858 {
1859         uint32_t i;
1860         struct object_entry **sorted_by_offset;
1861
1862         if (progress)
1863                 progress_state = start_progress(_("Counting objects"),
1864                                                 to_pack.nr_objects);
1865
1866         sorted_by_offset = xcalloc(to_pack.nr_objects, sizeof(struct object_entry *));
1867         for (i = 0; i < to_pack.nr_objects; i++)
1868                 sorted_by_offset[i] = to_pack.objects + i;
1869         QSORT(sorted_by_offset, to_pack.nr_objects, pack_offset_sort);
1870
1871         for (i = 0; i < to_pack.nr_objects; i++) {
1872                 struct object_entry *entry = sorted_by_offset[i];
1873                 check_object(entry);
1874                 if (entry->type_valid &&
1875                     oe_size_greater_than(&to_pack, entry, big_file_threshold))
1876                         entry->no_try_delta = 1;
1877                 display_progress(progress_state, i + 1);
1878         }
1879         stop_progress(&progress_state);
1880
1881         /*
1882          * This must happen in a second pass, since we rely on the delta
1883          * information for the whole list being completed.
1884          */
1885         for (i = 0; i < to_pack.nr_objects; i++)
1886                 break_delta_chains(&to_pack.objects[i]);
1887
1888         free(sorted_by_offset);
1889 }
1890
1891 /*
1892  * We search for deltas in a list sorted by type, by filename hash, and then
1893  * by size, so that we see progressively smaller and smaller files.
1894  * That's because we prefer deltas to be from the bigger file
1895  * to the smaller -- deletes are potentially cheaper, but perhaps
1896  * more importantly, the bigger file is likely the more recent
1897  * one.  The deepest deltas are therefore the oldest objects which are
1898  * less susceptible to be accessed often.
1899  */
1900 static int type_size_sort(const void *_a, const void *_b)
1901 {
1902         const struct object_entry *a = *(struct object_entry **)_a;
1903         const struct object_entry *b = *(struct object_entry **)_b;
1904         enum object_type a_type = oe_type(a);
1905         enum object_type b_type = oe_type(b);
1906         unsigned long a_size = SIZE(a);
1907         unsigned long b_size = SIZE(b);
1908
1909         if (a_type > b_type)
1910                 return -1;
1911         if (a_type < b_type)
1912                 return 1;
1913         if (a->hash > b->hash)
1914                 return -1;
1915         if (a->hash < b->hash)
1916                 return 1;
1917         if (a->preferred_base > b->preferred_base)
1918                 return -1;
1919         if (a->preferred_base < b->preferred_base)
1920                 return 1;
1921         if (use_delta_islands) {
1922                 int island_cmp = island_delta_cmp(&a->idx.oid, &b->idx.oid);
1923                 if (island_cmp)
1924                         return island_cmp;
1925         }
1926         if (a_size > b_size)
1927                 return -1;
1928         if (a_size < b_size)
1929                 return 1;
1930         return a < b ? -1 : (a > b);  /* newest first */
1931 }
1932
1933 struct unpacked {
1934         struct object_entry *entry;
1935         void *data;
1936         struct delta_index *index;
1937         unsigned depth;
1938 };
1939
1940 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1941                            unsigned long delta_size)
1942 {
1943         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1944                 return 0;
1945
1946         if (delta_size < cache_max_small_delta_size)
1947                 return 1;
1948
1949         /* cache delta, if objects are large enough compared to delta size */
1950         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1951                 return 1;
1952
1953         return 0;
1954 }
1955
1956 /* Protect access to object database */
1957 static pthread_mutex_t read_mutex;
1958 #define read_lock()             pthread_mutex_lock(&read_mutex)
1959 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1960
1961 /* Protect delta_cache_size */
1962 static pthread_mutex_t cache_mutex;
1963 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1964 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1965
1966 /*
1967  * Protect object list partitioning (e.g. struct thread_param) and
1968  * progress_state
1969  */
1970 static pthread_mutex_t progress_mutex;
1971 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1972 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1973
1974 /*
1975  * Access to struct object_entry is unprotected since each thread owns
1976  * a portion of the main object list. Just don't access object entries
1977  * ahead in the list because they can be stolen and would need
1978  * progress_mutex for protection.
1979  */
1980
1981 /*
1982  * Return the size of the object without doing any delta
1983  * reconstruction (so non-deltas are true object sizes, but deltas
1984  * return the size of the delta data).
1985  */
1986 unsigned long oe_get_size_slow(struct packing_data *pack,
1987                                const struct object_entry *e)
1988 {
1989         struct packed_git *p;
1990         struct pack_window *w_curs;
1991         unsigned char *buf;
1992         enum object_type type;
1993         unsigned long used, avail, size;
1994
1995         if (e->type_ != OBJ_OFS_DELTA && e->type_ != OBJ_REF_DELTA) {
1996                 read_lock();
1997                 if (oid_object_info(the_repository, &e->idx.oid, &size) < 0)
1998                         die(_("unable to get size of %s"),
1999                             oid_to_hex(&e->idx.oid));
2000                 read_unlock();
2001                 return size;
2002         }
2003
2004         p = oe_in_pack(pack, e);
2005         if (!p)
2006                 BUG("when e->type is a delta, it must belong to a pack");
2007
2008         read_lock();
2009         w_curs = NULL;
2010         buf = use_pack(p, &w_curs, e->in_pack_offset, &avail);
2011         used = unpack_object_header_buffer(buf, avail, &type, &size);
2012         if (used == 0)
2013                 die(_("unable to parse object header of %s"),
2014                     oid_to_hex(&e->idx.oid));
2015
2016         unuse_pack(&w_curs);
2017         read_unlock();
2018         return size;
2019 }
2020
2021 static int try_delta(struct unpacked *trg, struct unpacked *src,
2022                      unsigned max_depth, unsigned long *mem_usage)
2023 {
2024         struct object_entry *trg_entry = trg->entry;
2025         struct object_entry *src_entry = src->entry;
2026         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
2027         unsigned ref_depth;
2028         enum object_type type;
2029         void *delta_buf;
2030
2031         /* Don't bother doing diffs between different types */
2032         if (oe_type(trg_entry) != oe_type(src_entry))
2033                 return -1;
2034
2035         /*
2036          * We do not bother to try a delta that we discarded on an
2037          * earlier try, but only when reusing delta data.  Note that
2038          * src_entry that is marked as the preferred_base should always
2039          * be considered, as even if we produce a suboptimal delta against
2040          * it, we will still save the transfer cost, as we already know
2041          * the other side has it and we won't send src_entry at all.
2042          */
2043         if (reuse_delta && IN_PACK(trg_entry) &&
2044             IN_PACK(trg_entry) == IN_PACK(src_entry) &&
2045             !src_entry->preferred_base &&
2046             trg_entry->in_pack_type != OBJ_REF_DELTA &&
2047             trg_entry->in_pack_type != OBJ_OFS_DELTA)
2048                 return 0;
2049
2050         /* Let's not bust the allowed depth. */
2051         if (src->depth >= max_depth)
2052                 return 0;
2053
2054         /* Now some size filtering heuristics. */
2055         trg_size = SIZE(trg_entry);
2056         if (!DELTA(trg_entry)) {
2057                 max_size = trg_size/2 - the_hash_algo->rawsz;
2058                 ref_depth = 1;
2059         } else {
2060                 max_size = DELTA_SIZE(trg_entry);
2061                 ref_depth = trg->depth;
2062         }
2063         max_size = (uint64_t)max_size * (max_depth - src->depth) /
2064                                                 (max_depth - ref_depth + 1);
2065         if (max_size == 0)
2066                 return 0;
2067         src_size = SIZE(src_entry);
2068         sizediff = src_size < trg_size ? trg_size - src_size : 0;
2069         if (sizediff >= max_size)
2070                 return 0;
2071         if (trg_size < src_size / 32)
2072                 return 0;
2073
2074         if (!in_same_island(&trg->entry->idx.oid, &src->entry->idx.oid))
2075                 return 0;
2076
2077         /* Load data if not already done */
2078         if (!trg->data) {
2079                 read_lock();
2080                 trg->data = read_object_file(&trg_entry->idx.oid, &type, &sz);
2081                 read_unlock();
2082                 if (!trg->data)
2083                         die(_("object %s cannot be read"),
2084                             oid_to_hex(&trg_entry->idx.oid));
2085                 if (sz != trg_size)
2086                         die(_("object %s inconsistent object length (%"PRIuMAX" vs %"PRIuMAX")"),
2087                             oid_to_hex(&trg_entry->idx.oid), (uintmax_t)sz,
2088                             (uintmax_t)trg_size);
2089                 *mem_usage += sz;
2090         }
2091         if (!src->data) {
2092                 read_lock();
2093                 src->data = read_object_file(&src_entry->idx.oid, &type, &sz);
2094                 read_unlock();
2095                 if (!src->data) {
2096                         if (src_entry->preferred_base) {
2097                                 static int warned = 0;
2098                                 if (!warned++)
2099                                         warning(_("object %s cannot be read"),
2100                                                 oid_to_hex(&src_entry->idx.oid));
2101                                 /*
2102                                  * Those objects are not included in the
2103                                  * resulting pack.  Be resilient and ignore
2104                                  * them if they can't be read, in case the
2105                                  * pack could be created nevertheless.
2106                                  */
2107                                 return 0;
2108                         }
2109                         die(_("object %s cannot be read"),
2110                             oid_to_hex(&src_entry->idx.oid));
2111                 }
2112                 if (sz != src_size)
2113                         die(_("object %s inconsistent object length (%"PRIuMAX" vs %"PRIuMAX")"),
2114                             oid_to_hex(&src_entry->idx.oid), (uintmax_t)sz,
2115                             (uintmax_t)src_size);
2116                 *mem_usage += sz;
2117         }
2118         if (!src->index) {
2119                 src->index = create_delta_index(src->data, src_size);
2120                 if (!src->index) {
2121                         static int warned = 0;
2122                         if (!warned++)
2123                                 warning(_("suboptimal pack - out of memory"));
2124                         return 0;
2125                 }
2126                 *mem_usage += sizeof_delta_index(src->index);
2127         }
2128
2129         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
2130         if (!delta_buf)
2131                 return 0;
2132
2133         if (DELTA(trg_entry)) {
2134                 /* Prefer only shallower same-sized deltas. */
2135                 if (delta_size == DELTA_SIZE(trg_entry) &&
2136                     src->depth + 1 >= trg->depth) {
2137                         free(delta_buf);
2138                         return 0;
2139                 }
2140         }
2141
2142         /*
2143          * Handle memory allocation outside of the cache
2144          * accounting lock.  Compiler will optimize the strangeness
2145          * away when NO_PTHREADS is defined.
2146          */
2147         free(trg_entry->delta_data);
2148         cache_lock();
2149         if (trg_entry->delta_data) {
2150                 delta_cache_size -= DELTA_SIZE(trg_entry);
2151                 trg_entry->delta_data = NULL;
2152         }
2153         if (delta_cacheable(src_size, trg_size, delta_size)) {
2154                 delta_cache_size += delta_size;
2155                 cache_unlock();
2156                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
2157         } else {
2158                 cache_unlock();
2159                 free(delta_buf);
2160         }
2161
2162         SET_DELTA(trg_entry, src_entry);
2163         SET_DELTA_SIZE(trg_entry, delta_size);
2164         trg->depth = src->depth + 1;
2165
2166         return 1;
2167 }
2168
2169 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
2170 {
2171         struct object_entry *child = DELTA_CHILD(me);
2172         unsigned int m = n;
2173         while (child) {
2174                 unsigned int c = check_delta_limit(child, n + 1);
2175                 if (m < c)
2176                         m = c;
2177                 child = DELTA_SIBLING(child);
2178         }
2179         return m;
2180 }
2181
2182 static unsigned long free_unpacked(struct unpacked *n)
2183 {
2184         unsigned long freed_mem = sizeof_delta_index(n->index);
2185         free_delta_index(n->index);
2186         n->index = NULL;
2187         if (n->data) {
2188                 freed_mem += SIZE(n->entry);
2189                 FREE_AND_NULL(n->data);
2190         }
2191         n->entry = NULL;
2192         n->depth = 0;
2193         return freed_mem;
2194 }
2195
2196 static void find_deltas(struct object_entry **list, unsigned *list_size,
2197                         int window, int depth, unsigned *processed)
2198 {
2199         uint32_t i, idx = 0, count = 0;
2200         struct unpacked *array;
2201         unsigned long mem_usage = 0;
2202
2203         array = xcalloc(window, sizeof(struct unpacked));
2204
2205         for (;;) {
2206                 struct object_entry *entry;
2207                 struct unpacked *n = array + idx;
2208                 int j, max_depth, best_base = -1;
2209
2210                 progress_lock();
2211                 if (!*list_size) {
2212                         progress_unlock();
2213                         break;
2214                 }
2215                 entry = *list++;
2216                 (*list_size)--;
2217                 if (!entry->preferred_base) {
2218                         (*processed)++;
2219                         display_progress(progress_state, *processed);
2220                 }
2221                 progress_unlock();
2222
2223                 mem_usage -= free_unpacked(n);
2224                 n->entry = entry;
2225
2226                 while (window_memory_limit &&
2227                        mem_usage > window_memory_limit &&
2228                        count > 1) {
2229                         uint32_t tail = (idx + window - count) % window;
2230                         mem_usage -= free_unpacked(array + tail);
2231                         count--;
2232                 }
2233
2234                 /* We do not compute delta to *create* objects we are not
2235                  * going to pack.
2236                  */
2237                 if (entry->preferred_base)
2238                         goto next;
2239
2240                 /*
2241                  * If the current object is at pack edge, take the depth the
2242                  * objects that depend on the current object into account
2243                  * otherwise they would become too deep.
2244                  */
2245                 max_depth = depth;
2246                 if (DELTA_CHILD(entry)) {
2247                         max_depth -= check_delta_limit(entry, 0);
2248                         if (max_depth <= 0)
2249                                 goto next;
2250                 }
2251
2252                 j = window;
2253                 while (--j > 0) {
2254                         int ret;
2255                         uint32_t other_idx = idx + j;
2256                         struct unpacked *m;
2257                         if (other_idx >= window)
2258                                 other_idx -= window;
2259                         m = array + other_idx;
2260                         if (!m->entry)
2261                                 break;
2262                         ret = try_delta(n, m, max_depth, &mem_usage);
2263                         if (ret < 0)
2264                                 break;
2265                         else if (ret > 0)
2266                                 best_base = other_idx;
2267                 }
2268
2269                 /*
2270                  * If we decided to cache the delta data, then it is best
2271                  * to compress it right away.  First because we have to do
2272                  * it anyway, and doing it here while we're threaded will
2273                  * save a lot of time in the non threaded write phase,
2274                  * as well as allow for caching more deltas within
2275                  * the same cache size limit.
2276                  * ...
2277                  * But only if not writing to stdout, since in that case
2278                  * the network is most likely throttling writes anyway,
2279                  * and therefore it is best to go to the write phase ASAP
2280                  * instead, as we can afford spending more time compressing
2281                  * between writes at that moment.
2282                  */
2283                 if (entry->delta_data && !pack_to_stdout) {
2284                         unsigned long size;
2285
2286                         size = do_compress(&entry->delta_data, DELTA_SIZE(entry));
2287                         if (size < (1U << OE_Z_DELTA_BITS)) {
2288                                 entry->z_delta_size = size;
2289                                 cache_lock();
2290                                 delta_cache_size -= DELTA_SIZE(entry);
2291                                 delta_cache_size += entry->z_delta_size;
2292                                 cache_unlock();
2293                         } else {
2294                                 FREE_AND_NULL(entry->delta_data);
2295                                 entry->z_delta_size = 0;
2296                         }
2297                 }
2298
2299                 /* if we made n a delta, and if n is already at max
2300                  * depth, leaving it in the window is pointless.  we
2301                  * should evict it first.
2302                  */
2303                 if (DELTA(entry) && max_depth <= n->depth)
2304                         continue;
2305
2306                 /*
2307                  * Move the best delta base up in the window, after the
2308                  * currently deltified object, to keep it longer.  It will
2309                  * be the first base object to be attempted next.
2310                  */
2311                 if (DELTA(entry)) {
2312                         struct unpacked swap = array[best_base];
2313                         int dist = (window + idx - best_base) % window;
2314                         int dst = best_base;
2315                         while (dist--) {
2316                                 int src = (dst + 1) % window;
2317                                 array[dst] = array[src];
2318                                 dst = src;
2319                         }
2320                         array[dst] = swap;
2321                 }
2322
2323                 next:
2324                 idx++;
2325                 if (count + 1 < window)
2326                         count++;
2327                 if (idx >= window)
2328                         idx = 0;
2329         }
2330
2331         for (i = 0; i < window; ++i) {
2332                 free_delta_index(array[i].index);
2333                 free(array[i].data);
2334         }
2335         free(array);
2336 }
2337
2338 static void try_to_free_from_threads(size_t size)
2339 {
2340         read_lock();
2341         release_pack_memory(size);
2342         read_unlock();
2343 }
2344
2345 static try_to_free_t old_try_to_free_routine;
2346
2347 /*
2348  * The main object list is split into smaller lists, each is handed to
2349  * one worker.
2350  *
2351  * The main thread waits on the condition that (at least) one of the workers
2352  * has stopped working (which is indicated in the .working member of
2353  * struct thread_params).
2354  *
2355  * When a work thread has completed its work, it sets .working to 0 and
2356  * signals the main thread and waits on the condition that .data_ready
2357  * becomes 1.
2358  *
2359  * The main thread steals half of the work from the worker that has
2360  * most work left to hand it to the idle worker.
2361  */
2362
2363 struct thread_params {
2364         pthread_t thread;
2365         struct object_entry **list;
2366         unsigned list_size;
2367         unsigned remaining;
2368         int window;
2369         int depth;
2370         int working;
2371         int data_ready;
2372         pthread_mutex_t mutex;
2373         pthread_cond_t cond;
2374         unsigned *processed;
2375 };
2376
2377 static pthread_cond_t progress_cond;
2378
2379 /*
2380  * Mutex and conditional variable can't be statically-initialized on Windows.
2381  */
2382 static void init_threaded_search(void)
2383 {
2384         init_recursive_mutex(&read_mutex);
2385         pthread_mutex_init(&cache_mutex, NULL);
2386         pthread_mutex_init(&progress_mutex, NULL);
2387         pthread_cond_init(&progress_cond, NULL);
2388         old_try_to_free_routine = set_try_to_free_routine(try_to_free_from_threads);
2389 }
2390
2391 static void cleanup_threaded_search(void)
2392 {
2393         set_try_to_free_routine(old_try_to_free_routine);
2394         pthread_cond_destroy(&progress_cond);
2395         pthread_mutex_destroy(&read_mutex);
2396         pthread_mutex_destroy(&cache_mutex);
2397         pthread_mutex_destroy(&progress_mutex);
2398 }
2399
2400 static void *threaded_find_deltas(void *arg)
2401 {
2402         struct thread_params *me = arg;
2403
2404         progress_lock();
2405         while (me->remaining) {
2406                 progress_unlock();
2407
2408                 find_deltas(me->list, &me->remaining,
2409                             me->window, me->depth, me->processed);
2410
2411                 progress_lock();
2412                 me->working = 0;
2413                 pthread_cond_signal(&progress_cond);
2414                 progress_unlock();
2415
2416                 /*
2417                  * We must not set ->data_ready before we wait on the
2418                  * condition because the main thread may have set it to 1
2419                  * before we get here. In order to be sure that new
2420                  * work is available if we see 1 in ->data_ready, it
2421                  * was initialized to 0 before this thread was spawned
2422                  * and we reset it to 0 right away.
2423                  */
2424                 pthread_mutex_lock(&me->mutex);
2425                 while (!me->data_ready)
2426                         pthread_cond_wait(&me->cond, &me->mutex);
2427                 me->data_ready = 0;
2428                 pthread_mutex_unlock(&me->mutex);
2429
2430                 progress_lock();
2431         }
2432         progress_unlock();
2433         /* leave ->working 1 so that this doesn't get more work assigned */
2434         return NULL;
2435 }
2436
2437 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
2438                            int window, int depth, unsigned *processed)
2439 {
2440         struct thread_params *p;
2441         int i, ret, active_threads = 0;
2442
2443         init_threaded_search();
2444
2445         if (delta_search_threads <= 1) {
2446                 find_deltas(list, &list_size, window, depth, processed);
2447                 cleanup_threaded_search();
2448                 return;
2449         }
2450         if (progress > pack_to_stdout)
2451                 fprintf_ln(stderr, _("Delta compression using up to %d threads"),
2452                            delta_search_threads);
2453         p = xcalloc(delta_search_threads, sizeof(*p));
2454
2455         /* Partition the work amongst work threads. */
2456         for (i = 0; i < delta_search_threads; i++) {
2457                 unsigned sub_size = list_size / (delta_search_threads - i);
2458
2459                 /* don't use too small segments or no deltas will be found */
2460                 if (sub_size < 2*window && i+1 < delta_search_threads)
2461                         sub_size = 0;
2462
2463                 p[i].window = window;
2464                 p[i].depth = depth;
2465                 p[i].processed = processed;
2466                 p[i].working = 1;
2467                 p[i].data_ready = 0;
2468
2469                 /* try to split chunks on "path" boundaries */
2470                 while (sub_size && sub_size < list_size &&
2471                        list[sub_size]->hash &&
2472                        list[sub_size]->hash == list[sub_size-1]->hash)
2473                         sub_size++;
2474
2475                 p[i].list = list;
2476                 p[i].list_size = sub_size;
2477                 p[i].remaining = sub_size;
2478
2479                 list += sub_size;
2480                 list_size -= sub_size;
2481         }
2482
2483         /* Start work threads. */
2484         for (i = 0; i < delta_search_threads; i++) {
2485                 if (!p[i].list_size)
2486                         continue;
2487                 pthread_mutex_init(&p[i].mutex, NULL);
2488                 pthread_cond_init(&p[i].cond, NULL);
2489                 ret = pthread_create(&p[i].thread, NULL,
2490                                      threaded_find_deltas, &p[i]);
2491                 if (ret)
2492                         die(_("unable to create thread: %s"), strerror(ret));
2493                 active_threads++;
2494         }
2495
2496         /*
2497          * Now let's wait for work completion.  Each time a thread is done
2498          * with its work, we steal half of the remaining work from the
2499          * thread with the largest number of unprocessed objects and give
2500          * it to that newly idle thread.  This ensure good load balancing
2501          * until the remaining object list segments are simply too short
2502          * to be worth splitting anymore.
2503          */
2504         while (active_threads) {
2505                 struct thread_params *target = NULL;
2506                 struct thread_params *victim = NULL;
2507                 unsigned sub_size = 0;
2508
2509                 progress_lock();
2510                 for (;;) {
2511                         for (i = 0; !target && i < delta_search_threads; i++)
2512                                 if (!p[i].working)
2513                                         target = &p[i];
2514                         if (target)
2515                                 break;
2516                         pthread_cond_wait(&progress_cond, &progress_mutex);
2517                 }
2518
2519                 for (i = 0; i < delta_search_threads; i++)
2520                         if (p[i].remaining > 2*window &&
2521                             (!victim || victim->remaining < p[i].remaining))
2522                                 victim = &p[i];
2523                 if (victim) {
2524                         sub_size = victim->remaining / 2;
2525                         list = victim->list + victim->list_size - sub_size;
2526                         while (sub_size && list[0]->hash &&
2527                                list[0]->hash == list[-1]->hash) {
2528                                 list++;
2529                                 sub_size--;
2530                         }
2531                         if (!sub_size) {
2532                                 /*
2533                                  * It is possible for some "paths" to have
2534                                  * so many objects that no hash boundary
2535                                  * might be found.  Let's just steal the
2536                                  * exact half in that case.
2537                                  */
2538                                 sub_size = victim->remaining / 2;
2539                                 list -= sub_size;
2540                         }
2541                         target->list = list;
2542                         victim->list_size -= sub_size;
2543                         victim->remaining -= sub_size;
2544                 }
2545                 target->list_size = sub_size;
2546                 target->remaining = sub_size;
2547                 target->working = 1;
2548                 progress_unlock();
2549
2550                 pthread_mutex_lock(&target->mutex);
2551                 target->data_ready = 1;
2552                 pthread_cond_signal(&target->cond);
2553                 pthread_mutex_unlock(&target->mutex);
2554
2555                 if (!sub_size) {
2556                         pthread_join(target->thread, NULL);
2557                         pthread_cond_destroy(&target->cond);
2558                         pthread_mutex_destroy(&target->mutex);
2559                         active_threads--;
2560                 }
2561         }
2562         cleanup_threaded_search();
2563         free(p);
2564 }
2565
2566 static void add_tag_chain(const struct object_id *oid)
2567 {
2568         struct tag *tag;
2569
2570         /*
2571          * We catch duplicates already in add_object_entry(), but we'd
2572          * prefer to do this extra check to avoid having to parse the
2573          * tag at all if we already know that it's being packed (e.g., if
2574          * it was included via bitmaps, we would not have parsed it
2575          * previously).
2576          */
2577         if (packlist_find(&to_pack, oid->hash, NULL))
2578                 return;
2579
2580         tag = lookup_tag(the_repository, oid);
2581         while (1) {
2582                 if (!tag || parse_tag(tag) || !tag->tagged)
2583                         die(_("unable to pack objects reachable from tag %s"),
2584                             oid_to_hex(oid));
2585
2586                 add_object_entry(&tag->object.oid, OBJ_TAG, NULL, 0);
2587
2588                 if (tag->tagged->type != OBJ_TAG)
2589                         return;
2590
2591                 tag = (struct tag *)tag->tagged;
2592         }
2593 }
2594
2595 static int add_ref_tag(const char *path, const struct object_id *oid, int flag, void *cb_data)
2596 {
2597         struct object_id peeled;
2598
2599         if (starts_with(path, "refs/tags/") && /* is a tag? */
2600             !peel_ref(path, &peeled)    && /* peelable? */
2601             packlist_find(&to_pack, peeled.hash, NULL))      /* object packed? */
2602                 add_tag_chain(oid);
2603         return 0;
2604 }
2605
2606 static void prepare_pack(int window, int depth)
2607 {
2608         struct object_entry **delta_list;
2609         uint32_t i, nr_deltas;
2610         unsigned n;
2611
2612         if (use_delta_islands)
2613                 resolve_tree_islands(progress, &to_pack);
2614
2615         get_object_details();
2616
2617         /*
2618          * If we're locally repacking then we need to be doubly careful
2619          * from now on in order to make sure no stealth corruption gets
2620          * propagated to the new pack.  Clients receiving streamed packs
2621          * should validate everything they get anyway so no need to incur
2622          * the additional cost here in that case.
2623          */
2624         if (!pack_to_stdout)
2625                 do_check_packed_object_crc = 1;
2626
2627         if (!to_pack.nr_objects || !window || !depth)
2628                 return;
2629
2630         ALLOC_ARRAY(delta_list, to_pack.nr_objects);
2631         nr_deltas = n = 0;
2632
2633         for (i = 0; i < to_pack.nr_objects; i++) {
2634                 struct object_entry *entry = to_pack.objects + i;
2635
2636                 if (DELTA(entry))
2637                         /* This happens if we decided to reuse existing
2638                          * delta from a pack.  "reuse_delta &&" is implied.
2639                          */
2640                         continue;
2641
2642                 if (!entry->type_valid ||
2643                     oe_size_less_than(&to_pack, entry, 50))
2644                         continue;
2645
2646                 if (entry->no_try_delta)
2647                         continue;
2648
2649                 if (!entry->preferred_base) {
2650                         nr_deltas++;
2651                         if (oe_type(entry) < 0)
2652                                 die(_("unable to get type of object %s"),
2653                                     oid_to_hex(&entry->idx.oid));
2654                 } else {
2655                         if (oe_type(entry) < 0) {
2656                                 /*
2657                                  * This object is not found, but we
2658                                  * don't have to include it anyway.
2659                                  */
2660                                 continue;
2661                         }
2662                 }
2663
2664                 delta_list[n++] = entry;
2665         }
2666
2667         if (nr_deltas && n > 1) {
2668                 unsigned nr_done = 0;
2669                 if (progress)
2670                         progress_state = start_progress(_("Compressing objects"),
2671                                                         nr_deltas);
2672                 QSORT(delta_list, n, type_size_sort);
2673                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
2674                 stop_progress(&progress_state);
2675                 if (nr_done != nr_deltas)
2676                         die(_("inconsistency with delta count"));
2677         }
2678         free(delta_list);
2679 }
2680
2681 static int git_pack_config(const char *k, const char *v, void *cb)
2682 {
2683         if (!strcmp(k, "pack.window")) {
2684                 window = git_config_int(k, v);
2685                 return 0;
2686         }
2687         if (!strcmp(k, "pack.windowmemory")) {
2688                 window_memory_limit = git_config_ulong(k, v);
2689                 return 0;
2690         }
2691         if (!strcmp(k, "pack.depth")) {
2692                 depth = git_config_int(k, v);
2693                 return 0;
2694         }
2695         if (!strcmp(k, "pack.deltacachesize")) {
2696                 max_delta_cache_size = git_config_int(k, v);
2697                 return 0;
2698         }
2699         if (!strcmp(k, "pack.deltacachelimit")) {
2700                 cache_max_small_delta_size = git_config_int(k, v);
2701                 return 0;
2702         }
2703         if (!strcmp(k, "pack.writebitmaphashcache")) {
2704                 if (git_config_bool(k, v))
2705                         write_bitmap_options |= BITMAP_OPT_HASH_CACHE;
2706                 else
2707                         write_bitmap_options &= ~BITMAP_OPT_HASH_CACHE;
2708         }
2709         if (!strcmp(k, "pack.usebitmaps")) {
2710                 use_bitmap_index_default = git_config_bool(k, v);
2711                 return 0;
2712         }
2713         if (!strcmp(k, "pack.threads")) {
2714                 delta_search_threads = git_config_int(k, v);
2715                 if (delta_search_threads < 0)
2716                         die(_("invalid number of threads specified (%d)"),
2717                             delta_search_threads);
2718                 if (!HAVE_THREADS && delta_search_threads != 1) {
2719                         warning(_("no threads support, ignoring %s"), k);
2720                         delta_search_threads = 0;
2721                 }
2722                 return 0;
2723         }
2724         if (!strcmp(k, "pack.indexversion")) {
2725                 pack_idx_opts.version = git_config_int(k, v);
2726                 if (pack_idx_opts.version > 2)
2727                         die(_("bad pack.indexversion=%"PRIu32),
2728                             pack_idx_opts.version);
2729                 return 0;
2730         }
2731         return git_default_config(k, v, cb);
2732 }
2733
2734 static void read_object_list_from_stdin(void)
2735 {
2736         char line[GIT_MAX_HEXSZ + 1 + PATH_MAX + 2];
2737         struct object_id oid;
2738         const char *p;
2739
2740         for (;;) {
2741                 if (!fgets(line, sizeof(line), stdin)) {
2742                         if (feof(stdin))
2743                                 break;
2744                         if (!ferror(stdin))
2745                                 die("BUG: fgets returned NULL, not EOF, not error!");
2746                         if (errno != EINTR)
2747                                 die_errno("fgets");
2748                         clearerr(stdin);
2749                         continue;
2750                 }
2751                 if (line[0] == '-') {
2752                         if (get_oid_hex(line+1, &oid))
2753                                 die(_("expected edge object ID, got garbage:\n %s"),
2754                                     line);
2755                         add_preferred_base(&oid);
2756                         continue;
2757                 }
2758                 if (parse_oid_hex(line, &oid, &p))
2759                         die(_("expected object ID, got garbage:\n %s"), line);
2760
2761                 add_preferred_base_object(p + 1);
2762                 add_object_entry(&oid, OBJ_NONE, p + 1, 0);
2763         }
2764 }
2765
2766 /* Remember to update object flag allocation in object.h */
2767 #define OBJECT_ADDED (1u<<20)
2768
2769 static void show_commit(struct commit *commit, void *data)
2770 {
2771         add_object_entry(&commit->object.oid, OBJ_COMMIT, NULL, 0);
2772         commit->object.flags |= OBJECT_ADDED;
2773
2774         if (write_bitmap_index)
2775                 index_commit_for_bitmap(commit);
2776
2777         if (use_delta_islands)
2778                 propagate_island_marks(commit);
2779 }
2780
2781 static void show_object(struct object *obj, const char *name, void *data)
2782 {
2783         add_preferred_base_object(name);
2784         add_object_entry(&obj->oid, obj->type, name, 0);
2785         obj->flags |= OBJECT_ADDED;
2786
2787         if (use_delta_islands) {
2788                 const char *p;
2789                 unsigned depth;
2790                 struct object_entry *ent;
2791
2792                 /* the empty string is a root tree, which is depth 0 */
2793                 depth = *name ? 1 : 0;
2794                 for (p = strchr(name, '/'); p; p = strchr(p + 1, '/'))
2795                         depth++;
2796
2797                 ent = packlist_find(&to_pack, obj->oid.hash, NULL);
2798                 if (ent && depth > oe_tree_depth(&to_pack, ent))
2799                         oe_set_tree_depth(&to_pack, ent, depth);
2800         }
2801 }
2802
2803 static void show_object__ma_allow_any(struct object *obj, const char *name, void *data)
2804 {
2805         assert(arg_missing_action == MA_ALLOW_ANY);
2806
2807         /*
2808          * Quietly ignore ALL missing objects.  This avoids problems with
2809          * staging them now and getting an odd error later.
2810          */
2811         if (!has_object_file(&obj->oid))
2812                 return;
2813
2814         show_object(obj, name, data);
2815 }
2816
2817 static void show_object__ma_allow_promisor(struct object *obj, const char *name, void *data)
2818 {
2819         assert(arg_missing_action == MA_ALLOW_PROMISOR);
2820
2821         /*
2822          * Quietly ignore EXPECTED missing objects.  This avoids problems with
2823          * staging them now and getting an odd error later.
2824          */
2825         if (!has_object_file(&obj->oid) && is_promisor_object(&obj->oid))
2826                 return;
2827
2828         show_object(obj, name, data);
2829 }
2830
2831 static int option_parse_missing_action(const struct option *opt,
2832                                        const char *arg, int unset)
2833 {
2834         assert(arg);
2835         assert(!unset);
2836
2837         if (!strcmp(arg, "error")) {
2838                 arg_missing_action = MA_ERROR;
2839                 fn_show_object = show_object;
2840                 return 0;
2841         }
2842
2843         if (!strcmp(arg, "allow-any")) {
2844                 arg_missing_action = MA_ALLOW_ANY;
2845                 fetch_if_missing = 0;
2846                 fn_show_object = show_object__ma_allow_any;
2847                 return 0;
2848         }
2849
2850         if (!strcmp(arg, "allow-promisor")) {
2851                 arg_missing_action = MA_ALLOW_PROMISOR;
2852                 fetch_if_missing = 0;
2853                 fn_show_object = show_object__ma_allow_promisor;
2854                 return 0;
2855         }
2856
2857         die(_("invalid value for --missing"));
2858         return 0;
2859 }
2860
2861 static void show_edge(struct commit *commit)
2862 {
2863         add_preferred_base(&commit->object.oid);
2864 }
2865
2866 struct in_pack_object {
2867         off_t offset;
2868         struct object *object;
2869 };
2870
2871 struct in_pack {
2872         unsigned int alloc;
2873         unsigned int nr;
2874         struct in_pack_object *array;
2875 };
2876
2877 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
2878 {
2879         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->oid.hash, p);
2880         in_pack->array[in_pack->nr].object = object;
2881         in_pack->nr++;
2882 }
2883
2884 /*
2885  * Compare the objects in the offset order, in order to emulate the
2886  * "git rev-list --objects" output that produced the pack originally.
2887  */
2888 static int ofscmp(const void *a_, const void *b_)
2889 {
2890         struct in_pack_object *a = (struct in_pack_object *)a_;
2891         struct in_pack_object *b = (struct in_pack_object *)b_;
2892
2893         if (a->offset < b->offset)
2894                 return -1;
2895         else if (a->offset > b->offset)
2896                 return 1;
2897         else
2898                 return oidcmp(&a->object->oid, &b->object->oid);
2899 }
2900
2901 static void add_objects_in_unpacked_packs(struct rev_info *revs)
2902 {
2903         struct packed_git *p;
2904         struct in_pack in_pack;
2905         uint32_t i;
2906
2907         memset(&in_pack, 0, sizeof(in_pack));
2908
2909         for (p = get_all_packs(the_repository); p; p = p->next) {
2910                 struct object_id oid;
2911                 struct object *o;
2912
2913                 if (!p->pack_local || p->pack_keep || p->pack_keep_in_core)
2914                         continue;
2915                 if (open_pack_index(p))
2916                         die(_("cannot open pack index"));
2917
2918                 ALLOC_GROW(in_pack.array,
2919                            in_pack.nr + p->num_objects,
2920                            in_pack.alloc);
2921
2922                 for (i = 0; i < p->num_objects; i++) {
2923                         nth_packed_object_oid(&oid, p, i);
2924                         o = lookup_unknown_object(oid.hash);
2925                         if (!(o->flags & OBJECT_ADDED))
2926                                 mark_in_pack_object(o, p, &in_pack);
2927                         o->flags |= OBJECT_ADDED;
2928                 }
2929         }
2930
2931         if (in_pack.nr) {
2932                 QSORT(in_pack.array, in_pack.nr, ofscmp);
2933                 for (i = 0; i < in_pack.nr; i++) {
2934                         struct object *o = in_pack.array[i].object;
2935                         add_object_entry(&o->oid, o->type, "", 0);
2936                 }
2937         }
2938         free(in_pack.array);
2939 }
2940
2941 static int add_loose_object(const struct object_id *oid, const char *path,
2942                             void *data)
2943 {
2944         enum object_type type = oid_object_info(the_repository, oid, NULL);
2945
2946         if (type < 0) {
2947                 warning(_("loose object at %s could not be examined"), path);
2948                 return 0;
2949         }
2950
2951         add_object_entry(oid, type, "", 0);
2952         return 0;
2953 }
2954
2955 /*
2956  * We actually don't even have to worry about reachability here.
2957  * add_object_entry will weed out duplicates, so we just add every
2958  * loose object we find.
2959  */
2960 static void add_unreachable_loose_objects(void)
2961 {
2962         for_each_loose_file_in_objdir(get_object_directory(),
2963                                       add_loose_object,
2964                                       NULL, NULL, NULL);
2965 }
2966
2967 static int has_sha1_pack_kept_or_nonlocal(const struct object_id *oid)
2968 {
2969         static struct packed_git *last_found = (void *)1;
2970         struct packed_git *p;
2971
2972         p = (last_found != (void *)1) ? last_found :
2973                                         get_all_packs(the_repository);
2974
2975         while (p) {
2976                 if ((!p->pack_local || p->pack_keep ||
2977                                 p->pack_keep_in_core) &&
2978                         find_pack_entry_one(oid->hash, p)) {
2979                         last_found = p;
2980                         return 1;
2981                 }
2982                 if (p == last_found)
2983                         p = get_all_packs(the_repository);
2984                 else
2985                         p = p->next;
2986                 if (p == last_found)
2987                         p = p->next;
2988         }
2989         return 0;
2990 }
2991
2992 /*
2993  * Store a list of sha1s that are should not be discarded
2994  * because they are either written too recently, or are
2995  * reachable from another object that was.
2996  *
2997  * This is filled by get_object_list.
2998  */
2999 static struct oid_array recent_objects;
3000
3001 static int loosened_object_can_be_discarded(const struct object_id *oid,
3002                                             timestamp_t mtime)
3003 {
3004         if (!unpack_unreachable_expiration)
3005                 return 0;
3006         if (mtime > unpack_unreachable_expiration)
3007                 return 0;
3008         if (oid_array_lookup(&recent_objects, oid) >= 0)
3009                 return 0;
3010         return 1;
3011 }
3012
3013 static void loosen_unused_packed_objects(struct rev_info *revs)
3014 {
3015         struct packed_git *p;
3016         uint32_t i;
3017         struct object_id oid;
3018
3019         for (p = get_all_packs(the_repository); p; p = p->next) {
3020                 if (!p->pack_local || p->pack_keep || p->pack_keep_in_core)
3021                         continue;
3022
3023                 if (open_pack_index(p))
3024                         die(_("cannot open pack index"));
3025
3026                 for (i = 0; i < p->num_objects; i++) {
3027                         nth_packed_object_oid(&oid, p, i);
3028                         if (!packlist_find(&to_pack, oid.hash, NULL) &&
3029                             !has_sha1_pack_kept_or_nonlocal(&oid) &&
3030                             !loosened_object_can_be_discarded(&oid, p->mtime))
3031                                 if (force_object_loose(&oid, p->mtime))
3032                                         die(_("unable to force loose object"));
3033                 }
3034         }
3035 }
3036
3037 /*
3038  * This tracks any options which pack-reuse code expects to be on, or which a
3039  * reader of the pack might not understand, and which would therefore prevent
3040  * blind reuse of what we have on disk.
3041  */
3042 static int pack_options_allow_reuse(void)
3043 {
3044         return pack_to_stdout &&
3045                allow_ofs_delta &&
3046                !ignore_packed_keep_on_disk &&
3047                !ignore_packed_keep_in_core &&
3048                (!local || !have_non_local_packs) &&
3049                !incremental;
3050 }
3051
3052 static int get_object_list_from_bitmap(struct rev_info *revs)
3053 {
3054         if (!(bitmap_git = prepare_bitmap_walk(revs)))
3055                 return -1;
3056
3057         if (pack_options_allow_reuse() &&
3058             !reuse_partial_packfile_from_bitmap(
3059                         bitmap_git,
3060                         &reuse_packfile,
3061                         &reuse_packfile_objects,
3062                         &reuse_packfile_offset)) {
3063                 assert(reuse_packfile_objects);
3064                 nr_result += reuse_packfile_objects;
3065                 display_progress(progress_state, nr_result);
3066         }
3067
3068         traverse_bitmap_commit_list(bitmap_git, &add_object_entry_from_bitmap);
3069         return 0;
3070 }
3071
3072 static void record_recent_object(struct object *obj,
3073                                  const char *name,
3074                                  void *data)
3075 {
3076         oid_array_append(&recent_objects, &obj->oid);
3077 }
3078
3079 static void record_recent_commit(struct commit *commit, void *data)
3080 {
3081         oid_array_append(&recent_objects, &commit->object.oid);
3082 }
3083
3084 static void get_object_list(int ac, const char **av)
3085 {
3086         struct rev_info revs;
3087         char line[1000];
3088         int flags = 0;
3089         int save_warning;
3090
3091         repo_init_revisions(the_repository, &revs, NULL);
3092         save_commit_buffer = 0;
3093         revs.allow_exclude_promisor_objects_opt = 1;
3094         setup_revisions(ac, av, &revs, NULL);
3095
3096         /* make sure shallows are read */
3097         is_repository_shallow(the_repository);
3098
3099         save_warning = warn_on_object_refname_ambiguity;
3100         warn_on_object_refname_ambiguity = 0;
3101
3102         while (fgets(line, sizeof(line), stdin) != NULL) {
3103                 int len = strlen(line);
3104                 if (len && line[len - 1] == '\n')
3105                         line[--len] = 0;
3106                 if (!len)
3107                         break;
3108                 if (*line == '-') {
3109                         if (!strcmp(line, "--not")) {
3110                                 flags ^= UNINTERESTING;
3111                                 write_bitmap_index = 0;
3112                                 continue;
3113                         }
3114                         if (starts_with(line, "--shallow ")) {
3115                                 struct object_id oid;
3116                                 if (get_oid_hex(line + 10, &oid))
3117                                         die("not an SHA-1 '%s'", line + 10);
3118                                 register_shallow(the_repository, &oid);
3119                                 use_bitmap_index = 0;
3120                                 continue;
3121                         }
3122                         die(_("not a rev '%s'"), line);
3123                 }
3124                 if (handle_revision_arg(line, &revs, flags, REVARG_CANNOT_BE_FILENAME))
3125                         die(_("bad revision '%s'"), line);
3126         }
3127
3128         warn_on_object_refname_ambiguity = save_warning;
3129
3130         if (use_bitmap_index && !get_object_list_from_bitmap(&revs))
3131                 return;
3132
3133         if (use_delta_islands)
3134                 load_delta_islands();
3135
3136         if (prepare_revision_walk(&revs))
3137                 die(_("revision walk setup failed"));
3138         mark_edges_uninteresting(&revs, show_edge);
3139
3140         if (!fn_show_object)
3141                 fn_show_object = show_object;
3142         traverse_commit_list_filtered(&filter_options, &revs,
3143                                       show_commit, fn_show_object, NULL,
3144                                       NULL);
3145
3146         if (unpack_unreachable_expiration) {
3147                 revs.ignore_missing_links = 1;
3148                 if (add_unseen_recent_objects_to_traversal(&revs,
3149                                 unpack_unreachable_expiration))
3150                         die(_("unable to add recent objects"));
3151                 if (prepare_revision_walk(&revs))
3152                         die(_("revision walk setup failed"));
3153                 traverse_commit_list(&revs, record_recent_commit,
3154                                      record_recent_object, NULL);
3155         }
3156
3157         if (keep_unreachable)
3158                 add_objects_in_unpacked_packs(&revs);
3159         if (pack_loose_unreachable)
3160                 add_unreachable_loose_objects();
3161         if (unpack_unreachable)
3162                 loosen_unused_packed_objects(&revs);
3163
3164         oid_array_clear(&recent_objects);
3165 }
3166
3167 static void add_extra_kept_packs(const struct string_list *names)
3168 {
3169         struct packed_git *p;
3170
3171         if (!names->nr)
3172                 return;
3173
3174         for (p = get_all_packs(the_repository); p; p = p->next) {
3175                 const char *name = basename(p->pack_name);
3176                 int i;
3177
3178                 if (!p->pack_local)
3179                         continue;
3180
3181                 for (i = 0; i < names->nr; i++)
3182                         if (!fspathcmp(name, names->items[i].string))
3183                                 break;
3184
3185                 if (i < names->nr) {
3186                         p->pack_keep_in_core = 1;
3187                         ignore_packed_keep_in_core = 1;
3188                         continue;
3189                 }
3190         }
3191 }
3192
3193 static int option_parse_index_version(const struct option *opt,
3194                                       const char *arg, int unset)
3195 {
3196         char *c;
3197         const char *val = arg;
3198
3199         BUG_ON_OPT_NEG(unset);
3200
3201         pack_idx_opts.version = strtoul(val, &c, 10);
3202         if (pack_idx_opts.version > 2)
3203                 die(_("unsupported index version %s"), val);
3204         if (*c == ',' && c[1])
3205                 pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
3206         if (*c || pack_idx_opts.off32_limit & 0x80000000)
3207                 die(_("bad index version '%s'"), val);
3208         return 0;
3209 }
3210
3211 static int option_parse_unpack_unreachable(const struct option *opt,
3212                                            const char *arg, int unset)
3213 {
3214         if (unset) {
3215                 unpack_unreachable = 0;
3216                 unpack_unreachable_expiration = 0;
3217         }
3218         else {
3219                 unpack_unreachable = 1;
3220                 if (arg)
3221                         unpack_unreachable_expiration = approxidate(arg);
3222         }
3223         return 0;
3224 }
3225
3226 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
3227 {
3228         int use_internal_rev_list = 0;
3229         int shallow = 0;
3230         int all_progress_implied = 0;
3231         struct argv_array rp = ARGV_ARRAY_INIT;
3232         int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
3233         int rev_list_index = 0;
3234         struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
3235         struct option pack_objects_options[] = {
3236                 OPT_SET_INT('q', "quiet", &progress,
3237                             N_("do not show progress meter"), 0),
3238                 OPT_SET_INT(0, "progress", &progress,
3239                             N_("show progress meter"), 1),
3240                 OPT_SET_INT(0, "all-progress", &progress,
3241                             N_("show progress meter during object writing phase"), 2),
3242                 OPT_BOOL(0, "all-progress-implied",
3243                          &all_progress_implied,
3244                          N_("similar to --all-progress when progress meter is shown")),
3245                 { OPTION_CALLBACK, 0, "index-version", NULL, N_("<version>[,<offset>]"),
3246                   N_("write the pack index file in the specified idx format version"),
3247                   PARSE_OPT_NONEG, option_parse_index_version },
3248                 OPT_MAGNITUDE(0, "max-pack-size", &pack_size_limit,
3249                               N_("maximum size of each output pack file")),
3250                 OPT_BOOL(0, "local", &local,
3251                          N_("ignore borrowed objects from alternate object store")),
3252                 OPT_BOOL(0, "incremental", &incremental,
3253                          N_("ignore packed objects")),
3254                 OPT_INTEGER(0, "window", &window,
3255                             N_("limit pack window by objects")),
3256                 OPT_MAGNITUDE(0, "window-memory", &window_memory_limit,
3257                               N_("limit pack window by memory in addition to object limit")),
3258                 OPT_INTEGER(0, "depth", &depth,
3259                             N_("maximum length of delta chain allowed in the resulting pack")),
3260                 OPT_BOOL(0, "reuse-delta", &reuse_delta,
3261                          N_("reuse existing deltas")),
3262                 OPT_BOOL(0, "reuse-object", &reuse_object,
3263                          N_("reuse existing objects")),
3264                 OPT_BOOL(0, "delta-base-offset", &allow_ofs_delta,
3265                          N_("use OFS_DELTA objects")),
3266                 OPT_INTEGER(0, "threads", &delta_search_threads,
3267                             N_("use threads when searching for best delta matches")),
3268                 OPT_BOOL(0, "non-empty", &non_empty,
3269                          N_("do not create an empty pack output")),
3270                 OPT_BOOL(0, "revs", &use_internal_rev_list,
3271                          N_("read revision arguments from standard input")),
3272                 OPT_SET_INT_F(0, "unpacked", &rev_list_unpacked,
3273                               N_("limit the objects to those that are not yet packed"),
3274                               1, PARSE_OPT_NONEG),
3275                 OPT_SET_INT_F(0, "all", &rev_list_all,
3276                               N_("include objects reachable from any reference"),
3277                               1, PARSE_OPT_NONEG),
3278                 OPT_SET_INT_F(0, "reflog", &rev_list_reflog,
3279                               N_("include objects referred by reflog entries"),
3280                               1, PARSE_OPT_NONEG),
3281                 OPT_SET_INT_F(0, "indexed-objects", &rev_list_index,
3282                               N_("include objects referred to by the index"),
3283                               1, PARSE_OPT_NONEG),
3284                 OPT_BOOL(0, "stdout", &pack_to_stdout,
3285                          N_("output pack to stdout")),
3286                 OPT_BOOL(0, "include-tag", &include_tag,
3287                          N_("include tag objects that refer to objects to be packed")),
3288                 OPT_BOOL(0, "keep-unreachable", &keep_unreachable,
3289                          N_("keep unreachable objects")),
3290                 OPT_BOOL(0, "pack-loose-unreachable", &pack_loose_unreachable,
3291                          N_("pack loose unreachable objects")),
3292                 { OPTION_CALLBACK, 0, "unpack-unreachable", NULL, N_("time"),
3293                   N_("unpack unreachable objects newer than <time>"),
3294                   PARSE_OPT_OPTARG, option_parse_unpack_unreachable },
3295                 OPT_BOOL(0, "thin", &thin,
3296                          N_("create thin packs")),
3297                 OPT_BOOL(0, "shallow", &shallow,
3298                          N_("create packs suitable for shallow fetches")),
3299                 OPT_BOOL(0, "honor-pack-keep", &ignore_packed_keep_on_disk,
3300                          N_("ignore packs that have companion .keep file")),
3301                 OPT_STRING_LIST(0, "keep-pack", &keep_pack_list, N_("name"),
3302                                 N_("ignore this pack")),
3303                 OPT_INTEGER(0, "compression", &pack_compression_level,
3304                             N_("pack compression level")),
3305                 OPT_SET_INT(0, "keep-true-parents", &grafts_replace_parents,
3306                             N_("do not hide commits by grafts"), 0),
3307                 OPT_BOOL(0, "use-bitmap-index", &use_bitmap_index,
3308                          N_("use a bitmap index if available to speed up counting objects")),
3309                 OPT_BOOL(0, "write-bitmap-index", &write_bitmap_index,
3310                          N_("write a bitmap index together with the pack index")),
3311                 OPT_PARSE_LIST_OBJECTS_FILTER(&filter_options),
3312                 { OPTION_CALLBACK, 0, "missing", NULL, N_("action"),
3313                   N_("handling for missing objects"), PARSE_OPT_NONEG,
3314                   option_parse_missing_action },
3315                 OPT_BOOL(0, "exclude-promisor-objects", &exclude_promisor_objects,
3316                          N_("do not pack objects in promisor packfiles")),
3317                 OPT_BOOL(0, "delta-islands", &use_delta_islands,
3318                          N_("respect islands during delta compression")),
3319                 OPT_END(),
3320         };
3321
3322         if (DFS_NUM_STATES > (1 << OE_DFS_STATE_BITS))
3323                 BUG("too many dfs states, increase OE_DFS_STATE_BITS");
3324
3325         read_replace_refs = 0;
3326
3327         reset_pack_idx_option(&pack_idx_opts);
3328         git_config(git_pack_config, NULL);
3329
3330         progress = isatty(2);
3331         argc = parse_options(argc, argv, prefix, pack_objects_options,
3332                              pack_usage, 0);
3333
3334         if (argc) {
3335                 base_name = argv[0];
3336                 argc--;
3337         }
3338         if (pack_to_stdout != !base_name || argc)
3339                 usage_with_options(pack_usage, pack_objects_options);
3340
3341         if (depth >= (1 << OE_DEPTH_BITS)) {
3342                 warning(_("delta chain depth %d is too deep, forcing %d"),
3343                         depth, (1 << OE_DEPTH_BITS) - 1);
3344                 depth = (1 << OE_DEPTH_BITS) - 1;
3345         }
3346         if (cache_max_small_delta_size >= (1U << OE_Z_DELTA_BITS)) {
3347                 warning(_("pack.deltaCacheLimit is too high, forcing %d"),
3348                         (1U << OE_Z_DELTA_BITS) - 1);
3349                 cache_max_small_delta_size = (1U << OE_Z_DELTA_BITS) - 1;
3350         }
3351
3352         argv_array_push(&rp, "pack-objects");
3353         if (thin) {
3354                 use_internal_rev_list = 1;
3355                 argv_array_push(&rp, shallow
3356                                 ? "--objects-edge-aggressive"
3357                                 : "--objects-edge");
3358         } else
3359                 argv_array_push(&rp, "--objects");
3360
3361         if (rev_list_all) {
3362                 use_internal_rev_list = 1;
3363                 argv_array_push(&rp, "--all");
3364         }
3365         if (rev_list_reflog) {
3366                 use_internal_rev_list = 1;
3367                 argv_array_push(&rp, "--reflog");
3368         }
3369         if (rev_list_index) {
3370                 use_internal_rev_list = 1;
3371                 argv_array_push(&rp, "--indexed-objects");
3372         }
3373         if (rev_list_unpacked) {
3374                 use_internal_rev_list = 1;
3375                 argv_array_push(&rp, "--unpacked");
3376         }
3377
3378         if (exclude_promisor_objects) {
3379                 use_internal_rev_list = 1;
3380                 fetch_if_missing = 0;
3381                 argv_array_push(&rp, "--exclude-promisor-objects");
3382         }
3383         if (unpack_unreachable || keep_unreachable || pack_loose_unreachable)
3384                 use_internal_rev_list = 1;
3385
3386         if (!reuse_object)
3387                 reuse_delta = 0;
3388         if (pack_compression_level == -1)
3389                 pack_compression_level = Z_DEFAULT_COMPRESSION;
3390         else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
3391                 die(_("bad pack compression level %d"), pack_compression_level);
3392
3393         if (!delta_search_threads)      /* --threads=0 means autodetect */
3394                 delta_search_threads = online_cpus();
3395
3396         if (!HAVE_THREADS && delta_search_threads != 1)
3397                 warning(_("no threads support, ignoring --threads"));
3398         if (!pack_to_stdout && !pack_size_limit)
3399                 pack_size_limit = pack_size_limit_cfg;
3400         if (pack_to_stdout && pack_size_limit)
3401                 die(_("--max-pack-size cannot be used to build a pack for transfer"));
3402         if (pack_size_limit && pack_size_limit < 1024*1024) {
3403                 warning(_("minimum pack size limit is 1 MiB"));
3404                 pack_size_limit = 1024*1024;
3405         }
3406
3407         if (!pack_to_stdout && thin)
3408                 die(_("--thin cannot be used to build an indexable pack"));
3409
3410         if (keep_unreachable && unpack_unreachable)
3411                 die(_("--keep-unreachable and --unpack-unreachable are incompatible"));
3412         if (!rev_list_all || !rev_list_reflog || !rev_list_index)
3413                 unpack_unreachable_expiration = 0;
3414
3415         if (filter_options.choice) {
3416                 if (!pack_to_stdout)
3417                         die(_("cannot use --filter without --stdout"));
3418                 use_bitmap_index = 0;
3419         }
3420
3421         /*
3422          * "soft" reasons not to use bitmaps - for on-disk repack by default we want
3423          *
3424          * - to produce good pack (with bitmap index not-yet-packed objects are
3425          *   packed in suboptimal order).
3426          *
3427          * - to use more robust pack-generation codepath (avoiding possible
3428          *   bugs in bitmap code and possible bitmap index corruption).
3429          */
3430         if (!pack_to_stdout)
3431                 use_bitmap_index_default = 0;
3432
3433         if (use_bitmap_index < 0)
3434                 use_bitmap_index = use_bitmap_index_default;
3435
3436         /* "hard" reasons not to use bitmaps; these just won't work at all */
3437         if (!use_internal_rev_list || (!pack_to_stdout && write_bitmap_index) || is_repository_shallow(the_repository))
3438                 use_bitmap_index = 0;
3439
3440         if (pack_to_stdout || !rev_list_all)
3441                 write_bitmap_index = 0;
3442
3443         if (use_delta_islands)
3444                 argv_array_push(&rp, "--topo-order");
3445
3446         if (progress && all_progress_implied)
3447                 progress = 2;
3448
3449         add_extra_kept_packs(&keep_pack_list);
3450         if (ignore_packed_keep_on_disk) {
3451                 struct packed_git *p;
3452                 for (p = get_all_packs(the_repository); p; p = p->next)
3453                         if (p->pack_local && p->pack_keep)
3454                                 break;
3455                 if (!p) /* no keep-able packs found */
3456                         ignore_packed_keep_on_disk = 0;
3457         }
3458         if (local) {
3459                 /*
3460                  * unlike ignore_packed_keep_on_disk above, we do not
3461                  * want to unset "local" based on looking at packs, as
3462                  * it also covers non-local objects
3463                  */
3464                 struct packed_git *p;
3465                 for (p = get_all_packs(the_repository); p; p = p->next) {
3466                         if (!p->pack_local) {
3467                                 have_non_local_packs = 1;
3468                                 break;
3469                         }
3470                 }
3471         }
3472
3473         prepare_packing_data(&to_pack);
3474
3475         if (progress)
3476                 progress_state = start_progress(_("Enumerating objects"), 0);
3477         if (!use_internal_rev_list)
3478                 read_object_list_from_stdin();
3479         else {
3480                 get_object_list(rp.argc, rp.argv);
3481                 argv_array_clear(&rp);
3482         }
3483         cleanup_preferred_base();
3484         if (include_tag && nr_result)
3485                 for_each_ref(add_ref_tag, NULL);
3486         stop_progress(&progress_state);
3487
3488         if (non_empty && !nr_result)
3489                 return 0;
3490         if (nr_result)
3491                 prepare_pack(window, depth);
3492         write_pack_file();
3493         if (progress)
3494                 fprintf_ln(stderr,
3495                            _("Total %"PRIu32" (delta %"PRIu32"),"
3496                              " reused %"PRIu32" (delta %"PRIu32")"),
3497                            written, written_delta, reused, reused_delta);
3498         return 0;
3499 }