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

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