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

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "attr.h"
   4 #include "object.h"
   5 #include "blob.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "tree.h"
   9 #include "delta.h"
  10 #include "pack.h"
  11 #include "pack-revindex.h"
  12 #include "csum-file.h"
  13 #include "tree-walk.h"
  14 #include "diff.h"
  15 #include "revision.h"
  16 #include "list-objects.h"
  17 #include "pack-objects.h"
  18 #include "progress.h"
  19 #include "refs.h"
  20 #include "streaming.h"
  21 #include "thread-utils.h"
  22 #include "pack-bitmap.h"
  23 #include "reachable.h"
  24 #include "sha1-array.h"
  25 #include "argv-array.h"
  26
  27 static const char *pack_usage[] = {
  28         N_("git pack-objects --stdout [<options>...] [< <ref-list> | < <object-list>]"),
  29         N_("git pack-objects [<options>...] <base-name> [< <ref-list> | < <object-list>]"),
  30         NULL
  31 };
  32
  33 /*
  34  * Objects we are going to pack are collected in the `to_pack` structure.
  35  * It contains an array (dynamically expanded) of the object data, and a map
  36  * that can resolve SHA1s to their position in the array.
  37  */
  38 static struct packing_data to_pack;
  39
  40 static struct pack_idx_entry **written_list;
  41 static uint32_t nr_result, nr_written;
  42
  43 static int non_empty;
  44 static int reuse_delta = 1, reuse_object = 1;
  45 static int keep_unreachable, unpack_unreachable, include_tag;
  46 static unsigned long unpack_unreachable_expiration;
  47 static int local;
  48 static int incremental;
  49 static int ignore_packed_keep;
  50 static int allow_ofs_delta;
  51 static struct pack_idx_option pack_idx_opts;
  52 static const char *base_name;
  53 static int progress = 1;
  54 static int window = 10;
  55 static unsigned long pack_size_limit;
  56 static int depth = 50;
  57 static int delta_search_threads;
  58 static int pack_to_stdout;
  59 static int num_preferred_base;
  60 static struct progress *progress_state;
  61 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  62 static int pack_compression_seen;
  63
  64 static struct packed_git *reuse_packfile;
  65 static uint32_t reuse_packfile_objects;
  66 static off_t reuse_packfile_offset;
  67
  68 static int use_bitmap_index = 1;
  69 static int write_bitmap_index;
  70 static uint16_t write_bitmap_options;
  71
  72 static unsigned long delta_cache_size = 0;
  73 static unsigned long max_delta_cache_size = 256 * 1024 * 1024;
  74 static unsigned long cache_max_small_delta_size = 1000;
  75
  76 static unsigned long window_memory_limit = 0;
  77
  78 /*
  79  * stats
  80  */
  81 static uint32_t written, written_delta;
  82 static uint32_t reused, reused_delta;
  83
  84 /*
  85  * Indexed commits
  86  */
  87 static struct commit **indexed_commits;
  88 static unsigned int indexed_commits_nr;
  89 static unsigned int indexed_commits_alloc;
  90
  91 static void index_commit_for_bitmap(struct commit *commit)
  92 {
  93         if (indexed_commits_nr >= indexed_commits_alloc) {
  94                 indexed_commits_alloc = (indexed_commits_alloc + 32) * 2;
  95                 REALLOC_ARRAY(indexed_commits, indexed_commits_alloc);
  96         }
  97
  98         indexed_commits[indexed_commits_nr++] = commit;
  99 }
 100
 101 static void *get_delta(struct object_entry *entry)
 102 {
 103         unsigned long size, base_size, delta_size;
 104         void *buf, *base_buf, *delta_buf;
 105         enum object_type type;
 106
 107         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 108         if (!buf)
 109                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 110         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
 111         if (!base_buf)
 112                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 113         delta_buf = diff_delta(base_buf, base_size,
 114                                buf, size, &delta_size, 0);
 115         if (!delta_buf || delta_size != entry->delta_size)
 116                 die("delta size changed");
 117         free(buf);
 118         free(base_buf);
 119         return delta_buf;
 120 }
 121
 122 static unsigned long do_compress(void **pptr, unsigned long size)
 123 {
 124         git_zstream stream;
 125         void *in, *out;
 126         unsigned long maxsize;
 127
 128         git_deflate_init(&stream, pack_compression_level);
 129         maxsize = git_deflate_bound(&stream, size);
 130
 131         in = *pptr;
 132         out = xmalloc(maxsize);
 133         *pptr = out;
 134
 135         stream.next_in = in;
 136         stream.avail_in = size;
 137         stream.next_out = out;
 138         stream.avail_out = maxsize;
 139         while (git_deflate(&stream, Z_FINISH) == Z_OK)
 140                 ; /* nothing */
 141         git_deflate_end(&stream);
 142
 143         free(in);
 144         return stream.total_out;
 145 }
 146
 147 static unsigned long write_large_blob_data(struct git_istream *st, struct sha1file *f,
 148                                            const unsigned char *sha1)
 149 {
 150         git_zstream stream;
 151         unsigned char ibuf[1024 * 16];
 152         unsigned char obuf[1024 * 16];
 153         unsigned long olen = 0;
 154
 155         git_deflate_init(&stream, pack_compression_level);
 156
 157         for (;;) {
 158                 ssize_t readlen;
 159                 int zret = Z_OK;
 160                 readlen = read_istream(st, ibuf, sizeof(ibuf));
 161                 if (readlen == -1)
 162                         die(_("unable to read %s"), sha1_to_hex(sha1));
 163
 164                 stream.next_in = ibuf;
 165                 stream.avail_in = readlen;
 166                 while ((stream.avail_in || readlen == 0) &&
 167                        (zret == Z_OK || zret == Z_BUF_ERROR)) {
 168                         stream.next_out = obuf;
 169                         stream.avail_out = sizeof(obuf);
 170                         zret = git_deflate(&stream, readlen ? 0 : Z_FINISH);
 171                         sha1write(f, obuf, stream.next_out - obuf);
 172                         olen += stream.next_out - obuf;
 173                 }
 174                 if (stream.avail_in)
 175                         die(_("deflate error (%d)"), zret);
 176                 if (readlen == 0) {
 177                         if (zret != Z_STREAM_END)
 178                                 die(_("deflate error (%d)"), zret);
 179                         break;
 180                 }
 181         }
 182         git_deflate_end(&stream);
 183         return olen;
 184 }
 185
 186 /*
 187  * we are going to reuse the existing object data as is.  make
 188  * sure it is not corrupt.
 189  */
 190 static int check_pack_inflate(struct packed_git *p,
 191                 struct pack_window **w_curs,
 192                 off_t offset,
 193                 off_t len,
 194                 unsigned long expect)
 195 {
 196         git_zstream stream;
 197         unsigned char fakebuf[4096], *in;
 198         int st;
 199
 200         memset(&stream, 0, sizeof(stream));
 201         git_inflate_init(&stream);
 202         do {
 203                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 204                 stream.next_in = in;
 205                 stream.next_out = fakebuf;
 206                 stream.avail_out = sizeof(fakebuf);
 207                 st = git_inflate(&stream, Z_FINISH);
 208                 offset += stream.next_in - in;
 209         } while (st == Z_OK || st == Z_BUF_ERROR);
 210         git_inflate_end(&stream);
 211         return (st == Z_STREAM_END &&
 212                 stream.total_out == expect &&
 213                 stream.total_in == len) ? 0 : -1;
 214 }
 215
 216 static void copy_pack_data(struct sha1file *f,
 217                 struct packed_git *p,
 218                 struct pack_window **w_curs,
 219                 off_t offset,
 220                 off_t len)
 221 {
 222         unsigned char *in;
 223         unsigned long avail;
 224
 225         while (len) {
 226                 in = use_pack(p, w_curs, offset, &avail);
 227                 if (avail > len)
 228                         avail = (unsigned long)len;
 229                 sha1write(f, in, avail);
 230                 offset += avail;
 231                 len -= avail;
 232         }
 233 }
 234
 235 /* Return 0 if we will bust the pack-size limit */
 236 static unsigned long write_no_reuse_object(struct sha1file *f, struct object_entry *entry,
 237                                            unsigned long limit, int usable_delta)
 238 {
 239         unsigned long size, datalen;
 240         unsigned char header[10], dheader[10];
 241         unsigned hdrlen;
 242         enum object_type type;
 243         void *buf;
 244         struct git_istream *st = NULL;
 245
 246         if (!usable_delta) {
 247                 if (entry->type == OBJ_BLOB &&
 248                     entry->size > big_file_threshold &&
 249                     (st = open_istream(entry->idx.sha1, &type, &size, NULL)) != NULL)
 250                         buf = NULL;
 251                 else {
 252                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 253                         if (!buf)
 254                                 die(_("unable to read %s"), sha1_to_hex(entry->idx.sha1));
 255                 }
 256                 /*
 257                  * make sure no cached delta data remains from a
 258                  * previous attempt before a pack split occurred.
 259                  */
 260                 free(entry->delta_data);
 261                 entry->delta_data = NULL;
 262                 entry->z_delta_size = 0;
 263         } else if (entry->delta_data) {
 264                 size = entry->delta_size;
 265                 buf = entry->delta_data;
 266                 entry->delta_data = NULL;
 267                 type = (allow_ofs_delta && entry->delta->idx.offset) ?
 268                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 269         } else {
 270                 buf = get_delta(entry);
 271                 size = entry->delta_size;
 272                 type = (allow_ofs_delta && entry->delta->idx.offset) ?
 273                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 274         }
 275
 276         if (st) /* large blob case, just assume we don't compress well */
 277                 datalen = size;
 278         else if (entry->z_delta_size)
 279                 datalen = entry->z_delta_size;
 280         else
 281                 datalen = do_compress(&buf, size);
 282
 283         /*
 284          * The object header is a byte of 'type' followed by zero or
 285          * more bytes of length.
 286          */
 287         hdrlen = encode_in_pack_object_header(type, size, header);
 288
 289         if (type == OBJ_OFS_DELTA) {
 290                 /*
 291                  * Deltas with relative base contain an additional
 292                  * encoding of the relative offset for the delta
 293                  * base from this object's position in the pack.
 294                  */
 295                 off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 296                 unsigned pos = sizeof(dheader) - 1;
 297                 dheader[pos] = ofs & 127;
 298                 while (ofs >>= 7)
 299                         dheader[--pos] = 128 | (--ofs & 127);
 300                 if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 301                         if (st)
 302                                 close_istream(st);
 303                         free(buf);
 304                         return 0;
 305                 }
 306                 sha1write(f, header, hdrlen);
 307                 sha1write(f, dheader + pos, sizeof(dheader) - pos);
 308                 hdrlen += sizeof(dheader) - pos;
 309         } else if (type == OBJ_REF_DELTA) {
 310                 /*
 311                  * Deltas with a base reference contain
 312                  * an additional 20 bytes for the base sha1.
 313                  */
 314                 if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 315                         if (st)
 316                                 close_istream(st);
 317                         free(buf);
 318                         return 0;
 319                 }
 320                 sha1write(f, header, hdrlen);
 321                 sha1write(f, entry->delta->idx.sha1, 20);
 322                 hdrlen += 20;
 323         } else {
 324                 if (limit && hdrlen + datalen + 20 >= limit) {
 325                         if (st)
 326                                 close_istream(st);
 327                         free(buf);
 328                         return 0;
 329                 }
 330                 sha1write(f, header, hdrlen);
 331         }
 332         if (st) {
 333                 datalen = write_large_blob_data(st, f, entry->idx.sha1);
 334                 close_istream(st);
 335         } else {
 336                 sha1write(f, buf, datalen);
 337                 free(buf);
 338         }
 339
 340         return hdrlen + datalen;
 341 }
 342
 343 /* Return 0 if we will bust the pack-size limit */
 344 static unsigned long write_reuse_object(struct sha1file *f, struct object_entry *entry,
 345                                         unsigned long limit, int usable_delta)
 346 {
 347         struct packed_git *p = entry->in_pack;
 348         struct pack_window *w_curs = NULL;
 349         struct revindex_entry *revidx;
 350         off_t offset;
 351         enum object_type type = entry->type;
 352         unsigned long datalen;
 353         unsigned char header[10], dheader[10];
 354         unsigned hdrlen;
 355
 356         if (entry->delta)
 357                 type = (allow_ofs_delta && entry->delta->idx.offset) ?
 358                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 359         hdrlen = encode_in_pack_object_header(type, entry->size, header);
 360
 361         offset = entry->in_pack_offset;
 362         revidx = find_pack_revindex(p, offset);
 363         datalen = revidx[1].offset - offset;
 364         if (!pack_to_stdout && p->index_version > 1 &&
 365             check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 366                 error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 367                 unuse_pack(&w_curs);
 368                 return write_no_reuse_object(f, entry, limit, usable_delta);
 369         }
 370
 371         offset += entry->in_pack_header_size;
 372         datalen -= entry->in_pack_header_size;
 373
 374         if (!pack_to_stdout && p->index_version == 1 &&
 375             check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
 376                 error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 377                 unuse_pack(&w_curs);
 378                 return write_no_reuse_object(f, entry, limit, usable_delta);
 379         }
 380
 381         if (type == OBJ_OFS_DELTA) {
 382                 off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 383                 unsigned pos = sizeof(dheader) - 1;
 384                 dheader[pos] = ofs & 127;
 385                 while (ofs >>= 7)
 386                         dheader[--pos] = 128 | (--ofs & 127);
 387                 if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 388                         unuse_pack(&w_curs);
 389                         return 0;
 390                 }
 391                 sha1write(f, header, hdrlen);
 392                 sha1write(f, dheader + pos, sizeof(dheader) - pos);
 393                 hdrlen += sizeof(dheader) - pos;
 394                 reused_delta++;
 395         } else if (type == OBJ_REF_DELTA) {
 396                 if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 397                         unuse_pack(&w_curs);
 398                         return 0;
 399                 }
 400                 sha1write(f, header, hdrlen);
 401                 sha1write(f, entry->delta->idx.sha1, 20);
 402                 hdrlen += 20;
 403                 reused_delta++;
 404         } else {
 405                 if (limit && hdrlen + datalen + 20 >= limit) {
 406                         unuse_pack(&w_curs);
 407                         return 0;
 408                 }
 409                 sha1write(f, header, hdrlen);
 410         }
 411         copy_pack_data(f, p, &w_curs, offset, datalen);
 412         unuse_pack(&w_curs);
 413         reused++;
 414         return hdrlen + datalen;
 415 }
 416
 417 /* Return 0 if we will bust the pack-size limit */
 418 static unsigned long write_object(struct sha1file *f,
 419                                   struct object_entry *entry,
 420                                   off_t write_offset)
 421 {
 422         unsigned long limit, len;
 423         int usable_delta, to_reuse;
 424
 425         if (!pack_to_stdout)
 426                 crc32_begin(f);
 427
 428         /* apply size limit if limited packsize and not first object */
 429         if (!pack_size_limit || !nr_written)
 430                 limit = 0;
 431         else if (pack_size_limit <= write_offset)
 432                 /*
 433                  * the earlier object did not fit the limit; avoid
 434                  * mistaking this with unlimited (i.e. limit = 0).
 435                  */
 436                 limit = 1;
 437         else
 438                 limit = pack_size_limit - write_offset;
 439
 440         if (!entry->delta)
 441                 usable_delta = 0;       /* no delta */
 442         else if (!pack_size_limit)
 443                usable_delta = 1;        /* unlimited packfile */
 444         else if (entry->delta->idx.offset == (off_t)-1)
 445                 usable_delta = 0;       /* base was written to another pack */
 446         else if (entry->delta->idx.offset)
 447                 usable_delta = 1;       /* base already exists in this pack */
 448         else
 449                 usable_delta = 0;       /* base could end up in another pack */
 450
 451         if (!reuse_object)
 452                 to_reuse = 0;   /* explicit */
 453         else if (!entry->in_pack)
 454                 to_reuse = 0;   /* can't reuse what we don't have */
 455         else if (entry->type == OBJ_REF_DELTA || entry->type == OBJ_OFS_DELTA)
 456                                 /* check_object() decided it for us ... */
 457                 to_reuse = usable_delta;
 458                                 /* ... but pack split may override that */
 459         else if (entry->type != entry->in_pack_type)
 460                 to_reuse = 0;   /* pack has delta which is unusable */
 461         else if (entry->delta)
 462                 to_reuse = 0;   /* we want to pack afresh */
 463         else
 464                 to_reuse = 1;   /* we have it in-pack undeltified,
 465                                  * and we do not need to deltify it.
 466                                  */
 467
 468         if (!to_reuse)
 469                 len = write_no_reuse_object(f, entry, limit, usable_delta);
 470         else
 471                 len = write_reuse_object(f, entry, limit, usable_delta);
 472         if (!len)
 473                 return 0;
 474
 475         if (usable_delta)
 476                 written_delta++;
 477         written++;
 478         if (!pack_to_stdout)
 479                 entry->idx.crc32 = crc32_end(f);
 480         return len;
 481 }
 482
 483 enum write_one_status {
 484         WRITE_ONE_SKIP = -1, /* already written */
 485         WRITE_ONE_BREAK = 0, /* writing this will bust the limit; not written */
 486         WRITE_ONE_WRITTEN = 1, /* normal */
 487         WRITE_ONE_RECURSIVE = 2 /* already scheduled to be written */
 488 };
 489
 490 static enum write_one_status write_one(struct sha1file *f,
 491                                        struct object_entry *e,
 492                                        off_t *offset)
 493 {
 494         unsigned long size;
 495         int recursing;
 496
 497         /*
 498          * we set offset to 1 (which is an impossible value) to mark
 499          * the fact that this object is involved in "write its base
 500          * first before writing a deltified object" recursion.
 501          */
 502         recursing = (e->idx.offset == 1);
 503         if (recursing) {
 504                 warning("recursive delta detected for object %s",
 505                         sha1_to_hex(e->idx.sha1));
 506                 return WRITE_ONE_RECURSIVE;
 507         } else if (e->idx.offset || e->preferred_base) {
 508                 /* offset is non zero if object is written already. */
 509                 return WRITE_ONE_SKIP;
 510         }
 511
 512         /* if we are deltified, write out base object first. */
 513         if (e->delta) {
 514                 e->idx.offset = 1; /* now recurse */
 515                 switch (write_one(f, e->delta, offset)) {
 516                 case WRITE_ONE_RECURSIVE:
 517                         /* we cannot depend on this one */
 518                         e->delta = NULL;
 519                         break;
 520                 default:
 521                         break;
 522                 case WRITE_ONE_BREAK:
 523                         e->idx.offset = recursing;
 524                         return WRITE_ONE_BREAK;
 525                 }
 526         }
 527
 528         e->idx.offset = *offset;
 529         size = write_object(f, e, *offset);
 530         if (!size) {
 531                 e->idx.offset = recursing;
 532                 return WRITE_ONE_BREAK;
 533         }
 534         written_list[nr_written++] = &e->idx;
 535
 536         /* make sure off_t is sufficiently large not to wrap */
 537         if (signed_add_overflows(*offset, size))
 538                 die("pack too large for current definition of off_t");
 539         *offset += size;
 540         return WRITE_ONE_WRITTEN;
 541 }
 542
 543 static int mark_tagged(const char *path, const struct object_id *oid, int flag,
 544                        void *cb_data)
 545 {
 546         unsigned char peeled[20];
 547         struct object_entry *entry = packlist_find(&to_pack, oid->hash, NULL);
 548
 549         if (entry)
 550                 entry->tagged = 1;
 551         if (!peel_ref(path, peeled)) {
 552                 entry = packlist_find(&to_pack, peeled, NULL);
 553                 if (entry)
 554                         entry->tagged = 1;
 555         }
 556         return 0;
 557 }
 558
 559 static inline void add_to_write_order(struct object_entry **wo,
 560                                unsigned int *endp,
 561                                struct object_entry *e)
 562 {
 563         if (e->filled)
 564                 return;
 565         wo[(*endp)++] = e;
 566         e->filled = 1;
 567 }
 568
 569 static void add_descendants_to_write_order(struct object_entry **wo,
 570                                            unsigned int *endp,
 571                                            struct object_entry *e)
 572 {
 573         int add_to_order = 1;
 574         while (e) {
 575                 if (add_to_order) {
 576                         struct object_entry *s;
 577                         /* add this node... */
 578                         add_to_write_order(wo, endp, e);
 579                         /* all its siblings... */
 580                         for (s = e->delta_sibling; s; s = s->delta_sibling) {
 581                                 add_to_write_order(wo, endp, s);
 582                         }
 583                 }
 584                 /* drop down a level to add left subtree nodes if possible */
 585                 if (e->delta_child) {
 586                         add_to_order = 1;
 587                         e = e->delta_child;
 588                 } else {
 589                         add_to_order = 0;
 590                         /* our sibling might have some children, it is next */
 591                         if (e->delta_sibling) {
 592                                 e = e->delta_sibling;
 593                                 continue;
 594                         }
 595                         /* go back to our parent node */
 596                         e = e->delta;
 597                         while (e && !e->delta_sibling) {
 598                                 /* we're on the right side of a subtree, keep
 599                                  * going up until we can go right again */
 600                                 e = e->delta;
 601                         }
 602                         if (!e) {
 603                                 /* done- we hit our original root node */
 604                                 return;
 605                         }
 606                         /* pass it off to sibling at this level */
 607                         e = e->delta_sibling;
 608                 }
 609         };
 610 }
 611
 612 static void add_family_to_write_order(struct object_entry **wo,
 613                                       unsigned int *endp,
 614                                       struct object_entry *e)
 615 {
 616         struct object_entry *root;
 617
 618         for (root = e; root->delta; root = root->delta)
 619                 ; /* nothing */
 620         add_descendants_to_write_order(wo, endp, root);
 621 }
 622
 623 static struct object_entry **compute_write_order(void)
 624 {
 625         unsigned int i, wo_end, last_untagged;
 626
 627         struct object_entry **wo;
 628         struct object_entry *objects = to_pack.objects;
 629
 630         for (i = 0; i < to_pack.nr_objects; i++) {
 631                 objects[i].tagged = 0;
 632                 objects[i].filled = 0;
 633                 objects[i].delta_child = NULL;
 634                 objects[i].delta_sibling = NULL;
 635         }
 636
 637         /*
 638          * Fully connect delta_child/delta_sibling network.
 639          * Make sure delta_sibling is sorted in the original
 640          * recency order.
 641          */
 642         for (i = to_pack.nr_objects; i > 0;) {
 643                 struct object_entry *e = &objects[--i];
 644                 if (!e->delta)
 645                         continue;
 646                 /* Mark me as the first child */
 647                 e->delta_sibling = e->delta->delta_child;
 648                 e->delta->delta_child = e;
 649         }
 650
 651         /*
 652          * Mark objects that are at the tip of tags.
 653          */
 654         for_each_tag_ref(mark_tagged, NULL);
 655
 656         /*
 657          * Give the objects in the original recency order until
 658          * we see a tagged tip.
 659          */
 660         ALLOC_ARRAY(wo, to_pack.nr_objects);
 661         for (i = wo_end = 0; i < to_pack.nr_objects; i++) {
 662                 if (objects[i].tagged)
 663                         break;
 664                 add_to_write_order(wo, &wo_end, &objects[i]);
 665         }
 666         last_untagged = i;
 667
 668         /*
 669          * Then fill all the tagged tips.
 670          */
 671         for (; i < to_pack.nr_objects; i++) {
 672                 if (objects[i].tagged)
 673                         add_to_write_order(wo, &wo_end, &objects[i]);
 674         }
 675
 676         /*
 677          * And then all remaining commits and tags.
 678          */
 679         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 680                 if (objects[i].type != OBJ_COMMIT &&
 681                     objects[i].type != OBJ_TAG)
 682                         continue;
 683                 add_to_write_order(wo, &wo_end, &objects[i]);
 684         }
 685
 686         /*
 687          * And then all the trees.
 688          */
 689         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 690                 if (objects[i].type != OBJ_TREE)
 691                         continue;
 692                 add_to_write_order(wo, &wo_end, &objects[i]);
 693         }
 694
 695         /*
 696          * Finally all the rest in really tight order
 697          */
 698         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 699                 if (!objects[i].filled)
 700                         add_family_to_write_order(wo, &wo_end, &objects[i]);
 701         }
 702
 703         if (wo_end != to_pack.nr_objects)
 704                 die("ordered %u objects, expected %"PRIu32, wo_end, to_pack.nr_objects);
 705
 706         return wo;
 707 }
 708
 709 static off_t write_reused_pack(struct sha1file *f)
 710 {
 711         unsigned char buffer[8192];
 712         off_t to_write, total;
 713         int fd;
 714
 715         if (!is_pack_valid(reuse_packfile))
 716                 die("packfile is invalid: %s", reuse_packfile->pack_name);
 717
 718         fd = git_open_noatime(reuse_packfile->pack_name);
 719         if (fd < 0)
 720                 die_errno("unable to open packfile for reuse: %s",
 721                           reuse_packfile->pack_name);
 722
 723         if (lseek(fd, sizeof(struct pack_header), SEEK_SET) == -1)
 724                 die_errno("unable to seek in reused packfile");
 725
 726         if (reuse_packfile_offset < 0)
 727                 reuse_packfile_offset = reuse_packfile->pack_size - 20;
 728
 729         total = to_write = reuse_packfile_offset - sizeof(struct pack_header);
 730
 731         while (to_write) {
 732                 int read_pack = xread(fd, buffer, sizeof(buffer));
 733
 734                 if (read_pack <= 0)
 735                         die_errno("unable to read from reused packfile");
 736
 737                 if (read_pack > to_write)
 738                         read_pack = to_write;
 739
 740                 sha1write(f, buffer, read_pack);
 741                 to_write -= read_pack;
 742
 743                 /*
 744                  * We don't know the actual number of objects written,
 745                  * only how many bytes written, how many bytes total, and
 746                  * how many objects total. So we can fake it by pretending all
 747                  * objects we are writing are the same size. This gives us a
 748                  * smooth progress meter, and at the end it matches the true
 749                  * answer.
 750                  */
 751                 written = reuse_packfile_objects *
 752                                 (((double)(total - to_write)) / total);
 753                 display_progress(progress_state, written);
 754         }
 755
 756         close(fd);
 757         written = reuse_packfile_objects;
 758         display_progress(progress_state, written);
 759         return reuse_packfile_offset - sizeof(struct pack_header);
 760 }
 761
 762 static void write_pack_file(void)
 763 {
 764         uint32_t i = 0, j;
 765         struct sha1file *f;
 766         off_t offset;
 767         uint32_t nr_remaining = nr_result;
 768         time_t last_mtime = 0;
 769         struct object_entry **write_order;
 770
 771         if (progress > pack_to_stdout)
 772                 progress_state = start_progress(_("Writing objects"), nr_result);
 773         ALLOC_ARRAY(written_list, to_pack.nr_objects);
 774         write_order = compute_write_order();
 775
 776         do {
 777                 unsigned char sha1[20];
 778                 char *pack_tmp_name = NULL;
 779
 780                 if (pack_to_stdout)
 781                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 782                 else
 783                         f = create_tmp_packfile(&pack_tmp_name);
 784
 785                 offset = write_pack_header(f, nr_remaining);
 786
 787                 if (reuse_packfile) {
 788                         off_t packfile_size;
 789                         assert(pack_to_stdout);
 790
 791                         packfile_size = write_reused_pack(f);
 792                         offset += packfile_size;
 793                 }
 794
 795                 nr_written = 0;
 796                 for (; i < to_pack.nr_objects; i++) {
 797                         struct object_entry *e = write_order[i];
 798                         if (write_one(f, e, &offset) == WRITE_ONE_BREAK)
 799                                 break;
 800                         display_progress(progress_state, written);
 801                 }
 802
 803                 /*
 804                  * Did we write the wrong # entries in the header?
 805                  * If so, rewrite it like in fast-import
 806                  */
 807                 if (pack_to_stdout) {
 808                         sha1close(f, sha1, CSUM_CLOSE);
 809                 } else if (nr_written == nr_remaining) {
 810                         sha1close(f, sha1, CSUM_FSYNC);
 811                 } else {
 812                         int fd = sha1close(f, sha1, 0);
 813                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
 814                                                  nr_written, sha1, offset);
 815                         close(fd);
 816                         write_bitmap_index = 0;
 817                 }
 818
 819                 if (!pack_to_stdout) {
 820                         struct stat st;
 821                         struct strbuf tmpname = STRBUF_INIT;
 822
 823                         /*
 824                          * Packs are runtime accessed in their mtime
 825                          * order since newer packs are more likely to contain
 826                          * younger objects.  So if we are creating multiple
 827                          * packs then we should modify the mtime of later ones
 828                          * to preserve this property.
 829                          */
 830                         if (stat(pack_tmp_name, &st) < 0) {
 831                                 warning("failed to stat %s: %s",
 832                                         pack_tmp_name, strerror(errno));
 833                         } else if (!last_mtime) {
 834                                 last_mtime = st.st_mtime;
 835                         } else {
 836                                 struct utimbuf utb;
 837                                 utb.actime = st.st_atime;
 838                                 utb.modtime = --last_mtime;
 839                                 if (utime(pack_tmp_name, &utb) < 0)
 840                                         warning("failed utime() on %s: %s",
 841                                                 pack_tmp_name, strerror(errno));
 842                         }
 843
 844                         strbuf_addf(&tmpname, "%s-", base_name);
 845
 846                         if (write_bitmap_index) {
 847                                 bitmap_writer_set_checksum(sha1);
 848                                 bitmap_writer_build_type_index(written_list, nr_written);
 849                         }
 850
 851                         finish_tmp_packfile(&tmpname, pack_tmp_name,
 852                                             written_list, nr_written,
 853                                             &pack_idx_opts, sha1);
 854
 855                         if (write_bitmap_index) {
 856                                 strbuf_addf(&tmpname, "%s.bitmap", sha1_to_hex(sha1));
 857
 858                                 stop_progress(&progress_state);
 859
 860                                 bitmap_writer_show_progress(progress);
 861                                 bitmap_writer_reuse_bitmaps(&to_pack);
 862                                 bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
 863                                 bitmap_writer_build(&to_pack);
 864                                 bitmap_writer_finish(written_list, nr_written,
 865                                                      tmpname.buf, write_bitmap_options);
 866                                 write_bitmap_index = 0;
 867                         }
 868
 869                         strbuf_release(&tmpname);
 870                         free(pack_tmp_name);
 871                         puts(sha1_to_hex(sha1));
 872                 }
 873
 874                 /* mark written objects as written to previous pack */
 875                 for (j = 0; j < nr_written; j++) {
 876                         written_list[j]->offset = (off_t)-1;
 877                 }
 878                 nr_remaining -= nr_written;
 879         } while (nr_remaining && i < to_pack.nr_objects);
 880
 881         free(written_list);
 882         free(write_order);
 883         stop_progress(&progress_state);
 884         if (written != nr_result)
 885                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
 886                         written, nr_result);
 887 }
 888
 889 static void setup_delta_attr_check(struct git_attr_check *check)
 890 {
 891         static struct git_attr *attr_delta;
 892
 893         if (!attr_delta)
 894                 attr_delta = git_attr("delta");
 895
 896         check[0].attr = attr_delta;
 897 }
 898
 899 static int no_try_delta(const char *path)
 900 {
 901         struct git_attr_check check[1];
 902
 903         setup_delta_attr_check(check);
 904         if (git_check_attr(path, ARRAY_SIZE(check), check))
 905                 return 0;
 906         if (ATTR_FALSE(check->value))
 907                 return 1;
 908         return 0;
 909 }
 910
 911 /*
 912  * When adding an object, check whether we have already added it
 913  * to our packing list. If so, we can skip. However, if we are
 914  * being asked to excludei t, but the previous mention was to include
 915  * it, make sure to adjust its flags and tweak our numbers accordingly.
 916  *
 917  * As an optimization, we pass out the index position where we would have
 918  * found the item, since that saves us from having to look it up again a
 919  * few lines later when we want to add the new entry.
 920  */
 921 static int have_duplicate_entry(const unsigned char *sha1,
 922                                 int exclude,
 923                                 uint32_t *index_pos)
 924 {
 925         struct object_entry *entry;
 926
 927         entry = packlist_find(&to_pack, sha1, index_pos);
 928         if (!entry)
 929                 return 0;
 930
 931         if (exclude) {
 932                 if (!entry->preferred_base)
 933                         nr_result--;
 934                 entry->preferred_base = 1;
 935         }
 936
 937         return 1;
 938 }
 939
 940 /*
 941  * Check whether we want the object in the pack (e.g., we do not want
 942  * objects found in non-local stores if the "--local" option was used).
 943  *
 944  * As a side effect of this check, we will find the packed version of this
 945  * object, if any. We therefore pass out the pack information to avoid having
 946  * to look it up again later.
 947  */
 948 static int want_object_in_pack(const unsigned char *sha1,
 949                                int exclude,
 950                                struct packed_git **found_pack,
 951                                off_t *found_offset)
 952 {
 953         struct packed_git *p;
 954
 955         if (!exclude && local && has_loose_object_nonlocal(sha1))
 956                 return 0;
 957
 958         *found_pack = NULL;
 959         *found_offset = 0;
 960
 961         for (p = packed_git; p; p = p->next) {
 962                 off_t offset = find_pack_entry_one(sha1, p);
 963                 if (offset) {
 964                         if (!*found_pack) {
 965                                 if (!is_pack_valid(p))
 966                                         continue;
 967                                 *found_offset = offset;
 968                                 *found_pack = p;
 969                         }
 970                         if (exclude)
 971                                 return 1;
 972                         if (incremental)
 973                                 return 0;
 974                         if (local && !p->pack_local)
 975                                 return 0;
 976                         if (ignore_packed_keep && p->pack_local && p->pack_keep)
 977                                 return 0;
 978                 }
 979         }
 980
 981         return 1;
 982 }
 983
 984 static void create_object_entry(const unsigned char *sha1,
 985                                 enum object_type type,
 986                                 uint32_t hash,
 987                                 int exclude,
 988                                 int no_try_delta,
 989                                 uint32_t index_pos,
 990                                 struct packed_git *found_pack,
 991                                 off_t found_offset)
 992 {
 993         struct object_entry *entry;
 994
 995         entry = packlist_alloc(&to_pack, sha1, index_pos);
 996         entry->hash = hash;
 997         if (type)
 998                 entry->type = type;
 999         if (exclude)
1000                 entry->preferred_base = 1;
1001         else
1002                 nr_result++;
1003         if (found_pack) {
1004                 entry->in_pack = found_pack;
1005                 entry->in_pack_offset = found_offset;
1006         }
1007
1008         entry->no_try_delta = no_try_delta;
1009 }
1010
1011 static const char no_closure_warning[] = N_(
1012 "disabling bitmap writing, as some objects are not being packed"
1013 );
1014
1015 static int add_object_entry(const unsigned char *sha1, enum object_type type,
1016                             const char *name, int exclude)
1017 {
1018         struct packed_git *found_pack;
1019         off_t found_offset;
1020         uint32_t index_pos;
1021
1022         if (have_duplicate_entry(sha1, exclude, &index_pos))
1023                 return 0;
1024
1025         if (!want_object_in_pack(sha1, exclude, &found_pack, &found_offset)) {
1026                 /* The pack is missing an object, so it will not have closure */
1027                 if (write_bitmap_index) {
1028                         warning(_(no_closure_warning));
1029                         write_bitmap_index = 0;
1030                 }
1031                 return 0;
1032         }
1033
1034         create_object_entry(sha1, type, pack_name_hash(name),
1035                             exclude, name && no_try_delta(name),
1036                             index_pos, found_pack, found_offset);
1037
1038         display_progress(progress_state, nr_result);
1039         return 1;
1040 }
1041
1042 static int add_object_entry_from_bitmap(const unsigned char *sha1,
1043                                         enum object_type type,
1044                                         int flags, uint32_t name_hash,
1045                                         struct packed_git *pack, off_t offset)
1046 {
1047         uint32_t index_pos;
1048
1049         if (have_duplicate_entry(sha1, 0, &index_pos))
1050                 return 0;
1051
1052         create_object_entry(sha1, type, name_hash, 0, 0, index_pos, pack, offset);
1053
1054         display_progress(progress_state, nr_result);
1055         return 1;
1056 }
1057
1058 struct pbase_tree_cache {
1059         unsigned char sha1[20];
1060         int ref;
1061         int temporary;
1062         void *tree_data;
1063         unsigned long tree_size;
1064 };
1065
1066 static struct pbase_tree_cache *(pbase_tree_cache[256]);
1067 static int pbase_tree_cache_ix(const unsigned char *sha1)
1068 {
1069         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
1070 }
1071 static int pbase_tree_cache_ix_incr(int ix)
1072 {
1073         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
1074 }
1075
1076 static struct pbase_tree {
1077         struct pbase_tree *next;
1078         /* This is a phony "cache" entry; we are not
1079          * going to evict it or find it through _get()
1080          * mechanism -- this is for the toplevel node that
1081          * would almost always change with any commit.
1082          */
1083         struct pbase_tree_cache pcache;
1084 } *pbase_tree;
1085
1086 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
1087 {
1088         struct pbase_tree_cache *ent, *nent;
1089         void *data;
1090         unsigned long size;
1091         enum object_type type;
1092         int neigh;
1093         int my_ix = pbase_tree_cache_ix(sha1);
1094         int available_ix = -1;
1095
1096         /* pbase-tree-cache acts as a limited hashtable.
1097          * your object will be found at your index or within a few
1098          * slots after that slot if it is cached.
1099          */
1100         for (neigh = 0; neigh < 8; neigh++) {
1101                 ent = pbase_tree_cache[my_ix];
1102                 if (ent && !hashcmp(ent->sha1, sha1)) {
1103                         ent->ref++;
1104                         return ent;
1105                 }
1106                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
1107                          ((0 <= available_ix) &&
1108                           (!ent && pbase_tree_cache[available_ix])))
1109                         available_ix = my_ix;
1110                 if (!ent)
1111                         break;
1112                 my_ix = pbase_tree_cache_ix_incr(my_ix);
1113         }
1114
1115         /* Did not find one.  Either we got a bogus request or
1116          * we need to read and perhaps cache.
1117          */
1118         data = read_sha1_file(sha1, &type, &size);
1119         if (!data)
1120                 return NULL;
1121         if (type != OBJ_TREE) {
1122                 free(data);
1123                 return NULL;
1124         }
1125
1126         /* We need to either cache or return a throwaway copy */
1127
1128         if (available_ix < 0)
1129                 ent = NULL;
1130         else {
1131                 ent = pbase_tree_cache[available_ix];
1132                 my_ix = available_ix;
1133         }
1134
1135         if (!ent) {
1136                 nent = xmalloc(sizeof(*nent));
1137                 nent->temporary = (available_ix < 0);
1138         }
1139         else {
1140                 /* evict and reuse */
1141                 free(ent->tree_data);
1142                 nent = ent;
1143         }
1144         hashcpy(nent->sha1, sha1);
1145         nent->tree_data = data;
1146         nent->tree_size = size;
1147         nent->ref = 1;
1148         if (!nent->temporary)
1149                 pbase_tree_cache[my_ix] = nent;
1150         return nent;
1151 }
1152
1153 static void pbase_tree_put(struct pbase_tree_cache *cache)
1154 {
1155         if (!cache->temporary) {
1156                 cache->ref--;
1157                 return;
1158         }
1159         free(cache->tree_data);
1160         free(cache);
1161 }
1162
1163 static int name_cmp_len(const char *name)
1164 {
1165         int i;
1166         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
1167                 ;
1168         return i;
1169 }
1170
1171 static void add_pbase_object(struct tree_desc *tree,
1172                              const char *name,
1173                              int cmplen,
1174                              const char *fullname)
1175 {
1176         struct name_entry entry;
1177         int cmp;
1178
1179         while (tree_entry(tree,&entry)) {
1180                 if (S_ISGITLINK(entry.mode))
1181                         continue;
1182                 cmp = tree_entry_len(&entry) != cmplen ? 1 :
1183                       memcmp(name, entry.path, cmplen);
1184                 if (cmp > 0)
1185                         continue;
1186                 if (cmp < 0)
1187                         return;
1188                 if (name[cmplen] != '/') {
1189                         add_object_entry(entry.sha1,
1190                                          object_type(entry.mode),
1191                                          fullname, 1);
1192                         return;
1193                 }
1194                 if (S_ISDIR(entry.mode)) {
1195                         struct tree_desc sub;
1196                         struct pbase_tree_cache *tree;
1197                         const char *down = name+cmplen+1;
1198                         int downlen = name_cmp_len(down);
1199
1200                         tree = pbase_tree_get(entry.sha1);
1201                         if (!tree)
1202                                 return;
1203                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1204
1205                         add_pbase_object(&sub, down, downlen, fullname);
1206                         pbase_tree_put(tree);
1207                 }
1208         }
1209 }
1210
1211 static unsigned *done_pbase_paths;
1212 static int done_pbase_paths_num;
1213 static int done_pbase_paths_alloc;
1214 static int done_pbase_path_pos(unsigned hash)
1215 {
1216         int lo = 0;
1217         int hi = done_pbase_paths_num;
1218         while (lo < hi) {
1219                 int mi = (hi + lo) / 2;
1220                 if (done_pbase_paths[mi] == hash)
1221                         return mi;
1222                 if (done_pbase_paths[mi] < hash)
1223                         hi = mi;
1224                 else
1225                         lo = mi + 1;
1226         }
1227         return -lo-1;
1228 }
1229
1230 static int check_pbase_path(unsigned hash)
1231 {
1232         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
1233         if (0 <= pos)
1234                 return 1;
1235         pos = -pos - 1;
1236         ALLOC_GROW(done_pbase_paths,
1237                    done_pbase_paths_num + 1,
1238                    done_pbase_paths_alloc);
1239         done_pbase_paths_num++;
1240         if (pos < done_pbase_paths_num)
1241                 memmove(done_pbase_paths + pos + 1,
1242                         done_pbase_paths + pos,
1243                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
1244         done_pbase_paths[pos] = hash;
1245         return 0;
1246 }
1247
1248 static void add_preferred_base_object(const char *name)
1249 {
1250         struct pbase_tree *it;
1251         int cmplen;
1252         unsigned hash = pack_name_hash(name);
1253
1254         if (!num_preferred_base || check_pbase_path(hash))
1255                 return;
1256
1257         cmplen = name_cmp_len(name);
1258         for (it = pbase_tree; it; it = it->next) {
1259                 if (cmplen == 0) {
1260                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
1261                 }
1262                 else {
1263                         struct tree_desc tree;
1264                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1265                         add_pbase_object(&tree, name, cmplen, name);
1266                 }
1267         }
1268 }
1269
1270 static void add_preferred_base(unsigned char *sha1)
1271 {
1272         struct pbase_tree *it;
1273         void *data;
1274         unsigned long size;
1275         unsigned char tree_sha1[20];
1276
1277         if (window <= num_preferred_base++)
1278                 return;
1279
1280         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
1281         if (!data)
1282                 return;
1283
1284         for (it = pbase_tree; it; it = it->next) {
1285                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
1286                         free(data);
1287                         return;
1288                 }
1289         }
1290
1291         it = xcalloc(1, sizeof(*it));
1292         it->next = pbase_tree;
1293         pbase_tree = it;
1294
1295         hashcpy(it->pcache.sha1, tree_sha1);
1296         it->pcache.tree_data = data;
1297         it->pcache.tree_size = size;
1298 }
1299
1300 static void cleanup_preferred_base(void)
1301 {
1302         struct pbase_tree *it;
1303         unsigned i;
1304
1305         it = pbase_tree;
1306         pbase_tree = NULL;
1307         while (it) {
1308                 struct pbase_tree *this = it;
1309                 it = this->next;
1310                 free(this->pcache.tree_data);
1311                 free(this);
1312         }
1313
1314         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1315                 if (!pbase_tree_cache[i])
1316                         continue;
1317                 free(pbase_tree_cache[i]->tree_data);
1318                 free(pbase_tree_cache[i]);
1319                 pbase_tree_cache[i] = NULL;
1320         }
1321
1322         free(done_pbase_paths);
1323         done_pbase_paths = NULL;
1324         done_pbase_paths_num = done_pbase_paths_alloc = 0;
1325 }
1326
1327 static void check_object(struct object_entry *entry)
1328 {
1329         if (entry->in_pack) {
1330                 struct packed_git *p = entry->in_pack;
1331                 struct pack_window *w_curs = NULL;
1332                 const unsigned char *base_ref = NULL;
1333                 struct object_entry *base_entry;
1334                 unsigned long used, used_0;
1335                 unsigned long avail;
1336                 off_t ofs;
1337                 unsigned char *buf, c;
1338
1339                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1340
1341                 /*
1342                  * We want in_pack_type even if we do not reuse delta
1343                  * since non-delta representations could still be reused.
1344                  */
1345                 used = unpack_object_header_buffer(buf, avail,
1346                                                    &entry->in_pack_type,
1347                                                    &entry->size);
1348                 if (used == 0)
1349                         goto give_up;
1350
1351                 /*
1352                  * Determine if this is a delta and if so whether we can
1353                  * reuse it or not.  Otherwise let's find out as cheaply as
1354                  * possible what the actual type and size for this object is.
1355                  */
1356                 switch (entry->in_pack_type) {
1357                 default:
1358                         /* Not a delta hence we've already got all we need. */
1359                         entry->type = entry->in_pack_type;
1360                         entry->in_pack_header_size = used;
1361                         if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1362                                 goto give_up;
1363                         unuse_pack(&w_curs);
1364                         return;
1365                 case OBJ_REF_DELTA:
1366                         if (reuse_delta && !entry->preferred_base)
1367                                 base_ref = use_pack(p, &w_curs,
1368                                                 entry->in_pack_offset + used, NULL);
1369                         entry->in_pack_header_size = used + 20;
1370                         break;
1371                 case OBJ_OFS_DELTA:
1372                         buf = use_pack(p, &w_curs,
1373                                        entry->in_pack_offset + used, NULL);
1374                         used_0 = 0;
1375                         c = buf[used_0++];
1376                         ofs = c & 127;
1377                         while (c & 128) {
1378                                 ofs += 1;
1379                                 if (!ofs || MSB(ofs, 7)) {
1380                                         error("delta base offset overflow in pack for %s",
1381                                               sha1_to_hex(entry->idx.sha1));
1382                                         goto give_up;
1383                                 }
1384                                 c = buf[used_0++];
1385                                 ofs = (ofs << 7) + (c & 127);
1386                         }
1387                         ofs = entry->in_pack_offset - ofs;
1388                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1389                                 error("delta base offset out of bound for %s",
1390                                       sha1_to_hex(entry->idx.sha1));
1391                                 goto give_up;
1392                         }
1393                         if (reuse_delta && !entry->preferred_base) {
1394                                 struct revindex_entry *revidx;
1395                                 revidx = find_pack_revindex(p, ofs);
1396                                 if (!revidx)
1397                                         goto give_up;
1398                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1399                         }
1400                         entry->in_pack_header_size = used + used_0;
1401                         break;
1402                 }
1403
1404                 if (base_ref && (base_entry = packlist_find(&to_pack, base_ref, NULL))) {
1405                         /*
1406                          * If base_ref was set above that means we wish to
1407                          * reuse delta data, and we even found that base
1408                          * in the list of objects we want to pack. Goodie!
1409                          *
1410                          * Depth value does not matter - find_deltas() will
1411                          * never consider reused delta as the base object to
1412                          * deltify other objects against, in order to avoid
1413                          * circular deltas.
1414                          */
1415                         entry->type = entry->in_pack_type;
1416                         entry->delta = base_entry;
1417                         entry->delta_size = entry->size;
1418                         entry->delta_sibling = base_entry->delta_child;
1419                         base_entry->delta_child = entry;
1420                         unuse_pack(&w_curs);
1421                         return;
1422                 }
1423
1424                 if (entry->type) {
1425                         /*
1426                          * This must be a delta and we already know what the
1427                          * final object type is.  Let's extract the actual
1428                          * object size from the delta header.
1429                          */
1430                         entry->size = get_size_from_delta(p, &w_curs,
1431                                         entry->in_pack_offset + entry->in_pack_header_size);
1432                         if (entry->size == 0)
1433                                 goto give_up;
1434                         unuse_pack(&w_curs);
1435                         return;
1436                 }
1437
1438                 /*
1439                  * No choice but to fall back to the recursive delta walk
1440                  * with sha1_object_info() to find about the object type
1441                  * at this point...
1442                  */
1443                 give_up:
1444                 unuse_pack(&w_curs);
1445         }
1446
1447         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1448         /*
1449          * The error condition is checked in prepare_pack().  This is
1450          * to permit a missing preferred base object to be ignored
1451          * as a preferred base.  Doing so can result in a larger
1452          * pack file, but the transfer will still take place.
1453          */
1454 }
1455
1456 static int pack_offset_sort(const void *_a, const void *_b)
1457 {
1458         const struct object_entry *a = *(struct object_entry **)_a;
1459         const struct object_entry *b = *(struct object_entry **)_b;
1460
1461         /* avoid filesystem trashing with loose objects */
1462         if (!a->in_pack && !b->in_pack)
1463                 return hashcmp(a->idx.sha1, b->idx.sha1);
1464
1465         if (a->in_pack < b->in_pack)
1466                 return -1;
1467         if (a->in_pack > b->in_pack)
1468                 return 1;
1469         return a->in_pack_offset < b->in_pack_offset ? -1 :
1470                         (a->in_pack_offset > b->in_pack_offset);
1471 }
1472
1473 static void get_object_details(void)
1474 {
1475         uint32_t i;
1476         struct object_entry **sorted_by_offset;
1477
1478         sorted_by_offset = xcalloc(to_pack.nr_objects, sizeof(struct object_entry *));
1479         for (i = 0; i < to_pack.nr_objects; i++)
1480                 sorted_by_offset[i] = to_pack.objects + i;
1481         qsort(sorted_by_offset, to_pack.nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1482
1483         for (i = 0; i < to_pack.nr_objects; i++) {
1484                 struct object_entry *entry = sorted_by_offset[i];
1485                 check_object(entry);
1486                 if (big_file_threshold < entry->size)
1487                         entry->no_try_delta = 1;
1488         }
1489
1490         free(sorted_by_offset);
1491 }
1492
1493 /*
1494  * We search for deltas in a list sorted by type, by filename hash, and then
1495  * by size, so that we see progressively smaller and smaller files.
1496  * That's because we prefer deltas to be from the bigger file
1497  * to the smaller -- deletes are potentially cheaper, but perhaps
1498  * more importantly, the bigger file is likely the more recent
1499  * one.  The deepest deltas are therefore the oldest objects which are
1500  * less susceptible to be accessed often.
1501  */
1502 static int type_size_sort(const void *_a, const void *_b)
1503 {
1504         const struct object_entry *a = *(struct object_entry **)_a;
1505         const struct object_entry *b = *(struct object_entry **)_b;
1506
1507         if (a->type > b->type)
1508                 return -1;
1509         if (a->type < b->type)
1510                 return 1;
1511         if (a->hash > b->hash)
1512                 return -1;
1513         if (a->hash < b->hash)
1514                 return 1;
1515         if (a->preferred_base > b->preferred_base)
1516                 return -1;
1517         if (a->preferred_base < b->preferred_base)
1518                 return 1;
1519         if (a->size > b->size)
1520                 return -1;
1521         if (a->size < b->size)
1522                 return 1;
1523         return a < b ? -1 : (a > b);  /* newest first */
1524 }
1525
1526 struct unpacked {
1527         struct object_entry *entry;
1528         void *data;
1529         struct delta_index *index;
1530         unsigned depth;
1531 };
1532
1533 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1534                            unsigned long delta_size)
1535 {
1536         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1537                 return 0;
1538
1539         if (delta_size < cache_max_small_delta_size)
1540                 return 1;
1541
1542         /* cache delta, if objects are large enough compared to delta size */
1543         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1544                 return 1;
1545
1546         return 0;
1547 }
1548
1549 #ifndef NO_PTHREADS
1550
1551 static pthread_mutex_t read_mutex;
1552 #define read_lock()             pthread_mutex_lock(&read_mutex)
1553 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1554
1555 static pthread_mutex_t cache_mutex;
1556 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1557 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1558
1559 static pthread_mutex_t progress_mutex;
1560 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1561 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1562
1563 #else
1564
1565 #define read_lock()             (void)0
1566 #define read_unlock()           (void)0
1567 #define cache_lock()            (void)0
1568 #define cache_unlock()          (void)0
1569 #define progress_lock()         (void)0
1570 #define progress_unlock()       (void)0
1571
1572 #endif
1573
1574 static int try_delta(struct unpacked *trg, struct unpacked *src,
1575                      unsigned max_depth, unsigned long *mem_usage)
1576 {
1577         struct object_entry *trg_entry = trg->entry;
1578         struct object_entry *src_entry = src->entry;
1579         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1580         unsigned ref_depth;
1581         enum object_type type;
1582         void *delta_buf;
1583
1584         /* Don't bother doing diffs between different types */
1585         if (trg_entry->type != src_entry->type)
1586                 return -1;
1587
1588         /*
1589          * We do not bother to try a delta that we discarded on an
1590          * earlier try, but only when reusing delta data.  Note that
1591          * src_entry that is marked as the preferred_base should always
1592          * be considered, as even if we produce a suboptimal delta against
1593          * it, we will still save the transfer cost, as we already know
1594          * the other side has it and we won't send src_entry at all.
1595          */
1596         if (reuse_delta && trg_entry->in_pack &&
1597             trg_entry->in_pack == src_entry->in_pack &&
1598             !src_entry->preferred_base &&
1599             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1600             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1601                 return 0;
1602
1603         /* Let's not bust the allowed depth. */
1604         if (src->depth >= max_depth)
1605                 return 0;
1606
1607         /* Now some size filtering heuristics. */
1608         trg_size = trg_entry->size;
1609         if (!trg_entry->delta) {
1610                 max_size = trg_size/2 - 20;
1611                 ref_depth = 1;
1612         } else {
1613                 max_size = trg_entry->delta_size;
1614                 ref_depth = trg->depth;
1615         }
1616         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1617                                                 (max_depth - ref_depth + 1);
1618         if (max_size == 0)
1619                 return 0;
1620         src_size = src_entry->size;
1621         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1622         if (sizediff >= max_size)
1623                 return 0;
1624         if (trg_size < src_size / 32)
1625                 return 0;
1626
1627         /* Load data if not already done */
1628         if (!trg->data) {
1629                 read_lock();
1630                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1631                 read_unlock();
1632                 if (!trg->data)
1633                         die("object %s cannot be read",
1634                             sha1_to_hex(trg_entry->idx.sha1));
1635                 if (sz != trg_size)
1636                         die("object %s inconsistent object length (%lu vs %lu)",
1637                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1638                 *mem_usage += sz;
1639         }
1640         if (!src->data) {
1641                 read_lock();
1642                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1643                 read_unlock();
1644                 if (!src->data) {
1645                         if (src_entry->preferred_base) {
1646                                 static int warned = 0;
1647                                 if (!warned++)
1648                                         warning("object %s cannot be read",
1649                                                 sha1_to_hex(src_entry->idx.sha1));
1650                                 /*
1651                                  * Those objects are not included in the
1652                                  * resulting pack.  Be resilient and ignore
1653                                  * them if they can't be read, in case the
1654                                  * pack could be created nevertheless.
1655                                  */
1656                                 return 0;
1657                         }
1658                         die("object %s cannot be read",
1659                             sha1_to_hex(src_entry->idx.sha1));
1660                 }
1661                 if (sz != src_size)
1662                         die("object %s inconsistent object length (%lu vs %lu)",
1663                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1664                 *mem_usage += sz;
1665         }
1666         if (!src->index) {
1667                 src->index = create_delta_index(src->data, src_size);
1668                 if (!src->index) {
1669                         static int warned = 0;
1670                         if (!warned++)
1671                                 warning("suboptimal pack - out of memory");
1672                         return 0;
1673                 }
1674                 *mem_usage += sizeof_delta_index(src->index);
1675         }
1676
1677         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1678         if (!delta_buf)
1679                 return 0;
1680
1681         if (trg_entry->delta) {
1682                 /* Prefer only shallower same-sized deltas. */
1683                 if (delta_size == trg_entry->delta_size &&
1684                     src->depth + 1 >= trg->depth) {
1685                         free(delta_buf);
1686                         return 0;
1687                 }
1688         }
1689
1690         /*
1691          * Handle memory allocation outside of the cache
1692          * accounting lock.  Compiler will optimize the strangeness
1693          * away when NO_PTHREADS is defined.
1694          */
1695         free(trg_entry->delta_data);
1696         cache_lock();
1697         if (trg_entry->delta_data) {
1698                 delta_cache_size -= trg_entry->delta_size;
1699                 trg_entry->delta_data = NULL;
1700         }
1701         if (delta_cacheable(src_size, trg_size, delta_size)) {
1702                 delta_cache_size += delta_size;
1703                 cache_unlock();
1704                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1705         } else {
1706                 cache_unlock();
1707                 free(delta_buf);
1708         }
1709
1710         trg_entry->delta = src_entry;
1711         trg_entry->delta_size = delta_size;
1712         trg->depth = src->depth + 1;
1713
1714         return 1;
1715 }
1716
1717 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1718 {
1719         struct object_entry *child = me->delta_child;
1720         unsigned int m = n;
1721         while (child) {
1722                 unsigned int c = check_delta_limit(child, n + 1);
1723                 if (m < c)
1724                         m = c;
1725                 child = child->delta_sibling;
1726         }
1727         return m;
1728 }
1729
1730 static unsigned long free_unpacked(struct unpacked *n)
1731 {
1732         unsigned long freed_mem = sizeof_delta_index(n->index);
1733         free_delta_index(n->index);
1734         n->index = NULL;
1735         if (n->data) {
1736                 freed_mem += n->entry->size;
1737                 free(n->data);
1738                 n->data = NULL;
1739         }
1740         n->entry = NULL;
1741         n->depth = 0;
1742         return freed_mem;
1743 }
1744
1745 static void find_deltas(struct object_entry **list, unsigned *list_size,
1746                         int window, int depth, unsigned *processed)
1747 {
1748         uint32_t i, idx = 0, count = 0;
1749         struct unpacked *array;
1750         unsigned long mem_usage = 0;
1751
1752         array = xcalloc(window, sizeof(struct unpacked));
1753
1754         for (;;) {
1755                 struct object_entry *entry;
1756                 struct unpacked *n = array + idx;
1757                 int j, max_depth, best_base = -1;
1758
1759                 progress_lock();
1760                 if (!*list_size) {
1761                         progress_unlock();
1762                         break;
1763                 }
1764                 entry = *list++;
1765                 (*list_size)--;
1766                 if (!entry->preferred_base) {
1767                         (*processed)++;
1768                         display_progress(progress_state, *processed);
1769                 }
1770                 progress_unlock();
1771
1772                 mem_usage -= free_unpacked(n);
1773                 n->entry = entry;
1774
1775                 while (window_memory_limit &&
1776                        mem_usage > window_memory_limit &&
1777                        count > 1) {
1778                         uint32_t tail = (idx + window - count) % window;
1779                         mem_usage -= free_unpacked(array + tail);
1780                         count--;
1781                 }
1782
1783                 /* We do not compute delta to *create* objects we are not
1784                  * going to pack.
1785                  */
1786                 if (entry->preferred_base)
1787                         goto next;
1788
1789                 /*
1790                  * If the current object is at pack edge, take the depth the
1791                  * objects that depend on the current object into account
1792                  * otherwise they would become too deep.
1793                  */
1794                 max_depth = depth;
1795                 if (entry->delta_child) {
1796                         max_depth -= check_delta_limit(entry, 0);
1797                         if (max_depth <= 0)
1798                                 goto next;
1799                 }
1800
1801                 j = window;
1802                 while (--j > 0) {
1803                         int ret;
1804                         uint32_t other_idx = idx + j;
1805                         struct unpacked *m;
1806                         if (other_idx >= window)
1807                                 other_idx -= window;
1808                         m = array + other_idx;
1809                         if (!m->entry)
1810                                 break;
1811                         ret = try_delta(n, m, max_depth, &mem_usage);
1812                         if (ret < 0)
1813                                 break;
1814                         else if (ret > 0)
1815                                 best_base = other_idx;
1816                 }
1817
1818                 /*
1819                  * If we decided to cache the delta data, then it is best
1820                  * to compress it right away.  First because we have to do
1821                  * it anyway, and doing it here while we're threaded will
1822                  * save a lot of time in the non threaded write phase,
1823                  * as well as allow for caching more deltas within
1824                  * the same cache size limit.
1825                  * ...
1826                  * But only if not writing to stdout, since in that case
1827                  * the network is most likely throttling writes anyway,
1828                  * and therefore it is best to go to the write phase ASAP
1829                  * instead, as we can afford spending more time compressing
1830                  * between writes at that moment.
1831                  */
1832                 if (entry->delta_data && !pack_to_stdout) {
1833                         entry->z_delta_size = do_compress(&entry->delta_data,
1834                                                           entry->delta_size);
1835                         cache_lock();
1836                         delta_cache_size -= entry->delta_size;
1837                         delta_cache_size += entry->z_delta_size;
1838                         cache_unlock();
1839                 }
1840
1841                 /* if we made n a delta, and if n is already at max
1842                  * depth, leaving it in the window is pointless.  we
1843                  * should evict it first.
1844                  */
1845                 if (entry->delta && max_depth <= n->depth)
1846                         continue;
1847
1848                 /*
1849                  * Move the best delta base up in the window, after the
1850                  * currently deltified object, to keep it longer.  It will
1851                  * be the first base object to be attempted next.
1852                  */
1853                 if (entry->delta) {
1854                         struct unpacked swap = array[best_base];
1855                         int dist = (window + idx - best_base) % window;
1856                         int dst = best_base;
1857                         while (dist--) {
1858                                 int src = (dst + 1) % window;
1859                                 array[dst] = array[src];
1860                                 dst = src;
1861                         }
1862                         array[dst] = swap;
1863                 }
1864
1865                 next:
1866                 idx++;
1867                 if (count + 1 < window)
1868                         count++;
1869                 if (idx >= window)
1870                         idx = 0;
1871         }
1872
1873         for (i = 0; i < window; ++i) {
1874                 free_delta_index(array[i].index);
1875                 free(array[i].data);
1876         }
1877         free(array);
1878 }
1879
1880 #ifndef NO_PTHREADS
1881
1882 static void try_to_free_from_threads(size_t size)
1883 {
1884         read_lock();
1885         release_pack_memory(size);
1886         read_unlock();
1887 }
1888
1889 static try_to_free_t old_try_to_free_routine;
1890
1891 /*
1892  * The main thread waits on the condition that (at least) one of the workers
1893  * has stopped working (which is indicated in the .working member of
1894  * struct thread_params).
1895  * When a work thread has completed its work, it sets .working to 0 and
1896  * signals the main thread and waits on the condition that .data_ready
1897  * becomes 1.
1898  */
1899
1900 struct thread_params {
1901         pthread_t thread;
1902         struct object_entry **list;
1903         unsigned list_size;
1904         unsigned remaining;
1905         int window;
1906         int depth;
1907         int working;
1908         int data_ready;
1909         pthread_mutex_t mutex;
1910         pthread_cond_t cond;
1911         unsigned *processed;
1912 };
1913
1914 static pthread_cond_t progress_cond;
1915
1916 /*
1917  * Mutex and conditional variable can't be statically-initialized on Windows.
1918  */
1919 static void init_threaded_search(void)
1920 {
1921         init_recursive_mutex(&read_mutex);
1922         pthread_mutex_init(&cache_mutex, NULL);
1923         pthread_mutex_init(&progress_mutex, NULL);
1924         pthread_cond_init(&progress_cond, NULL);
1925         old_try_to_free_routine = set_try_to_free_routine(try_to_free_from_threads);
1926 }
1927
1928 static void cleanup_threaded_search(void)
1929 {
1930         set_try_to_free_routine(old_try_to_free_routine);
1931         pthread_cond_destroy(&progress_cond);
1932         pthread_mutex_destroy(&read_mutex);
1933         pthread_mutex_destroy(&cache_mutex);
1934         pthread_mutex_destroy(&progress_mutex);
1935 }
1936
1937 static void *threaded_find_deltas(void *arg)
1938 {
1939         struct thread_params *me = arg;
1940
1941         while (me->remaining) {
1942                 find_deltas(me->list, &me->remaining,
1943                             me->window, me->depth, me->processed);
1944
1945                 progress_lock();
1946                 me->working = 0;
1947                 pthread_cond_signal(&progress_cond);
1948                 progress_unlock();
1949
1950                 /*
1951                  * We must not set ->data_ready before we wait on the
1952                  * condition because the main thread may have set it to 1
1953                  * before we get here. In order to be sure that new
1954                  * work is available if we see 1 in ->data_ready, it
1955                  * was initialized to 0 before this thread was spawned
1956                  * and we reset it to 0 right away.
1957                  */
1958                 pthread_mutex_lock(&me->mutex);
1959                 while (!me->data_ready)
1960                         pthread_cond_wait(&me->cond, &me->mutex);
1961                 me->data_ready = 0;
1962                 pthread_mutex_unlock(&me->mutex);
1963         }
1964         /* leave ->working 1 so that this doesn't get more work assigned */
1965         return NULL;
1966 }
1967
1968 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1969                            int window, int depth, unsigned *processed)
1970 {
1971         struct thread_params *p;
1972         int i, ret, active_threads = 0;
1973
1974         init_threaded_search();
1975
1976         if (delta_search_threads <= 1) {
1977                 find_deltas(list, &list_size, window, depth, processed);
1978                 cleanup_threaded_search();
1979                 return;
1980         }
1981         if (progress > pack_to_stdout)
1982                 fprintf(stderr, "Delta compression using up to %d threads.\n",
1983                                 delta_search_threads);
1984         p = xcalloc(delta_search_threads, sizeof(*p));
1985
1986         /* Partition the work amongst work threads. */
1987         for (i = 0; i < delta_search_threads; i++) {
1988                 unsigned sub_size = list_size / (delta_search_threads - i);
1989
1990                 /* don't use too small segments or no deltas will be found */
1991                 if (sub_size < 2*window && i+1 < delta_search_threads)
1992                         sub_size = 0;
1993
1994                 p[i].window = window;
1995                 p[i].depth = depth;
1996                 p[i].processed = processed;
1997                 p[i].working = 1;
1998                 p[i].data_ready = 0;
1999
2000                 /* try to split chunks on "path" boundaries */
2001                 while (sub_size && sub_size < list_size &&
2002                        list[sub_size]->hash &&
2003                        list[sub_size]->hash == list[sub_size-1]->hash)
2004                         sub_size++;
2005
2006                 p[i].list = list;
2007                 p[i].list_size = sub_size;
2008                 p[i].remaining = sub_size;
2009
2010                 list += sub_size;
2011                 list_size -= sub_size;
2012         }
2013
2014         /* Start work threads. */
2015         for (i = 0; i < delta_search_threads; i++) {
2016                 if (!p[i].list_size)
2017                         continue;
2018                 pthread_mutex_init(&p[i].mutex, NULL);
2019                 pthread_cond_init(&p[i].cond, NULL);
2020                 ret = pthread_create(&p[i].thread, NULL,
2021                                      threaded_find_deltas, &p[i]);
2022                 if (ret)
2023                         die("unable to create thread: %s", strerror(ret));
2024                 active_threads++;
2025         }
2026
2027         /*
2028          * Now let's wait for work completion.  Each time a thread is done
2029          * with its work, we steal half of the remaining work from the
2030          * thread with the largest number of unprocessed objects and give
2031          * it to that newly idle thread.  This ensure good load balancing
2032          * until the remaining object list segments are simply too short
2033          * to be worth splitting anymore.
2034          */
2035         while (active_threads) {
2036                 struct thread_params *target = NULL;
2037                 struct thread_params *victim = NULL;
2038                 unsigned sub_size = 0;
2039
2040                 progress_lock();
2041                 for (;;) {
2042                         for (i = 0; !target && i < delta_search_threads; i++)
2043                                 if (!p[i].working)
2044                                         target = &p[i];
2045                         if (target)
2046                                 break;
2047                         pthread_cond_wait(&progress_cond, &progress_mutex);
2048                 }
2049
2050                 for (i = 0; i < delta_search_threads; i++)
2051                         if (p[i].remaining > 2*window &&
2052                             (!victim || victim->remaining < p[i].remaining))
2053                                 victim = &p[i];
2054                 if (victim) {
2055                         sub_size = victim->remaining / 2;
2056                         list = victim->list + victim->list_size - sub_size;
2057                         while (sub_size && list[0]->hash &&
2058                                list[0]->hash == list[-1]->hash) {
2059                                 list++;
2060                                 sub_size--;
2061                         }
2062                         if (!sub_size) {
2063                                 /*
2064                                  * It is possible for some "paths" to have
2065                                  * so many objects that no hash boundary
2066                                  * might be found.  Let's just steal the
2067                                  * exact half in that case.
2068                                  */
2069                                 sub_size = victim->remaining / 2;
2070                                 list -= sub_size;
2071                         }
2072                         target->list = list;
2073                         victim->list_size -= sub_size;
2074                         victim->remaining -= sub_size;
2075                 }
2076                 target->list_size = sub_size;
2077                 target->remaining = sub_size;
2078                 target->working = 1;
2079                 progress_unlock();
2080
2081                 pthread_mutex_lock(&target->mutex);
2082                 target->data_ready = 1;
2083                 pthread_cond_signal(&target->cond);
2084                 pthread_mutex_unlock(&target->mutex);
2085
2086                 if (!sub_size) {
2087                         pthread_join(target->thread, NULL);
2088                         pthread_cond_destroy(&target->cond);
2089                         pthread_mutex_destroy(&target->mutex);
2090                         active_threads--;
2091                 }
2092         }
2093         cleanup_threaded_search();
2094         free(p);
2095 }
2096
2097 #else
2098 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
2099 #endif
2100
2101 static int add_ref_tag(const char *path, const struct object_id *oid, int flag, void *cb_data)
2102 {
2103         struct object_id peeled;
2104
2105         if (starts_with(path, "refs/tags/") && /* is a tag? */
2106             !peel_ref(path, peeled.hash)    && /* peelable? */
2107             packlist_find(&to_pack, peeled.hash, NULL))      /* object packed? */
2108                 add_object_entry(oid->hash, OBJ_TAG, NULL, 0);
2109         return 0;
2110 }
2111
2112 static void prepare_pack(int window, int depth)
2113 {
2114         struct object_entry **delta_list;
2115         uint32_t i, nr_deltas;
2116         unsigned n;
2117
2118         get_object_details();
2119
2120         /*
2121          * If we're locally repacking then we need to be doubly careful
2122          * from now on in order to make sure no stealth corruption gets
2123          * propagated to the new pack.  Clients receiving streamed packs
2124          * should validate everything they get anyway so no need to incur
2125          * the additional cost here in that case.
2126          */
2127         if (!pack_to_stdout)
2128                 do_check_packed_object_crc = 1;
2129
2130         if (!to_pack.nr_objects || !window || !depth)
2131                 return;
2132
2133         ALLOC_ARRAY(delta_list, to_pack.nr_objects);
2134         nr_deltas = n = 0;
2135
2136         for (i = 0; i < to_pack.nr_objects; i++) {
2137                 struct object_entry *entry = to_pack.objects + i;
2138
2139                 if (entry->delta)
2140                         /* This happens if we decided to reuse existing
2141                          * delta from a pack.  "reuse_delta &&" is implied.
2142                          */
2143                         continue;
2144
2145                 if (entry->size < 50)
2146                         continue;
2147
2148                 if (entry->no_try_delta)
2149                         continue;
2150
2151                 if (!entry->preferred_base) {
2152                         nr_deltas++;
2153                         if (entry->type < 0)
2154                                 die("unable to get type of object %s",
2155                                     sha1_to_hex(entry->idx.sha1));
2156                 } else {
2157                         if (entry->type < 0) {
2158                                 /*
2159                                  * This object is not found, but we
2160                                  * don't have to include it anyway.
2161                                  */
2162                                 continue;
2163                         }
2164                 }
2165
2166                 delta_list[n++] = entry;
2167         }
2168
2169         if (nr_deltas && n > 1) {
2170                 unsigned nr_done = 0;
2171                 if (progress)
2172                         progress_state = start_progress(_("Compressing objects"),
2173                                                         nr_deltas);
2174                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
2175                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
2176                 stop_progress(&progress_state);
2177                 if (nr_done != nr_deltas)
2178                         die("inconsistency with delta count");
2179         }
2180         free(delta_list);
2181 }
2182
2183 static int git_pack_config(const char *k, const char *v, void *cb)
2184 {
2185         if (!strcmp(k, "pack.window")) {
2186                 window = git_config_int(k, v);
2187                 return 0;
2188         }
2189         if (!strcmp(k, "pack.windowmemory")) {
2190                 window_memory_limit = git_config_ulong(k, v);
2191                 return 0;
2192         }
2193         if (!strcmp(k, "pack.depth")) {
2194                 depth = git_config_int(k, v);
2195                 return 0;
2196         }
2197         if (!strcmp(k, "pack.compression")) {
2198                 int level = git_config_int(k, v);
2199                 if (level == -1)
2200                         level = Z_DEFAULT_COMPRESSION;
2201                 else if (level < 0 || level > Z_BEST_COMPRESSION)
2202                         die("bad pack compression level %d", level);
2203                 pack_compression_level = level;
2204                 pack_compression_seen = 1;
2205                 return 0;
2206         }
2207         if (!strcmp(k, "pack.deltacachesize")) {
2208                 max_delta_cache_size = git_config_int(k, v);
2209                 return 0;
2210         }
2211         if (!strcmp(k, "pack.deltacachelimit")) {
2212                 cache_max_small_delta_size = git_config_int(k, v);
2213                 return 0;
2214         }
2215         if (!strcmp(k, "pack.writebitmaphashcache")) {
2216                 if (git_config_bool(k, v))
2217                         write_bitmap_options |= BITMAP_OPT_HASH_CACHE;
2218                 else
2219                         write_bitmap_options &= ~BITMAP_OPT_HASH_CACHE;
2220         }
2221         if (!strcmp(k, "pack.usebitmaps")) {
2222                 use_bitmap_index = git_config_bool(k, v);
2223                 return 0;
2224         }
2225         if (!strcmp(k, "pack.threads")) {
2226                 delta_search_threads = git_config_int(k, v);
2227                 if (delta_search_threads < 0)
2228                         die("invalid number of threads specified (%d)",
2229                             delta_search_threads);
2230 #ifdef NO_PTHREADS
2231                 if (delta_search_threads != 1)
2232                         warning("no threads support, ignoring %s", k);
2233 #endif
2234                 return 0;
2235         }
2236         if (!strcmp(k, "pack.indexversion")) {
2237                 pack_idx_opts.version = git_config_int(k, v);
2238                 if (pack_idx_opts.version > 2)
2239                         die("bad pack.indexversion=%"PRIu32,
2240                             pack_idx_opts.version);
2241                 return 0;
2242         }
2243         return git_default_config(k, v, cb);
2244 }
2245
2246 static void read_object_list_from_stdin(void)
2247 {
2248         char line[40 + 1 + PATH_MAX + 2];
2249         unsigned char sha1[20];
2250
2251         for (;;) {
2252                 if (!fgets(line, sizeof(line), stdin)) {
2253                         if (feof(stdin))
2254                                 break;
2255                         if (!ferror(stdin))
2256                                 die("fgets returned NULL, not EOF, not error!");
2257                         if (errno != EINTR)
2258                                 die_errno("fgets");
2259                         clearerr(stdin);
2260                         continue;
2261                 }
2262                 if (line[0] == '-') {
2263                         if (get_sha1_hex(line+1, sha1))
2264                                 die("expected edge sha1, got garbage:\n %s",
2265                                     line);
2266                         add_preferred_base(sha1);
2267                         continue;
2268                 }
2269                 if (get_sha1_hex(line, sha1))
2270                         die("expected sha1, got garbage:\n %s", line);
2271
2272                 add_preferred_base_object(line+41);
2273                 add_object_entry(sha1, 0, line+41, 0);
2274         }
2275 }
2276
2277 #define OBJECT_ADDED (1u<<20)
2278
2279 static void show_commit(struct commit *commit, void *data)
2280 {
2281         add_object_entry(commit->object.oid.hash, OBJ_COMMIT, NULL, 0);
2282         commit->object.flags |= OBJECT_ADDED;
2283
2284         if (write_bitmap_index)
2285                 index_commit_for_bitmap(commit);
2286 }
2287
2288 static void show_object(struct object *obj, const char *name, void *data)
2289 {
2290         add_preferred_base_object(name);
2291         add_object_entry(obj->oid.hash, obj->type, name, 0);
2292         obj->flags |= OBJECT_ADDED;
2293 }
2294
2295 static void show_edge(struct commit *commit)
2296 {
2297         add_preferred_base(commit->object.oid.hash);
2298 }
2299
2300 struct in_pack_object {
2301         off_t offset;
2302         struct object *object;
2303 };
2304
2305 struct in_pack {
2306         int alloc;
2307         int nr;
2308         struct in_pack_object *array;
2309 };
2310
2311 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
2312 {
2313         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->oid.hash, p);
2314         in_pack->array[in_pack->nr].object = object;
2315         in_pack->nr++;
2316 }
2317
2318 /*
2319  * Compare the objects in the offset order, in order to emulate the
2320  * "git rev-list --objects" output that produced the pack originally.
2321  */
2322 static int ofscmp(const void *a_, const void *b_)
2323 {
2324         struct in_pack_object *a = (struct in_pack_object *)a_;
2325         struct in_pack_object *b = (struct in_pack_object *)b_;
2326
2327         if (a->offset < b->offset)
2328                 return -1;
2329         else if (a->offset > b->offset)
2330                 return 1;
2331         else
2332                 return oidcmp(&a->object->oid, &b->object->oid);
2333 }
2334
2335 static void add_objects_in_unpacked_packs(struct rev_info *revs)
2336 {
2337         struct packed_git *p;
2338         struct in_pack in_pack;
2339         uint32_t i;
2340
2341         memset(&in_pack, 0, sizeof(in_pack));
2342
2343         for (p = packed_git; p; p = p->next) {
2344                 const unsigned char *sha1;
2345                 struct object *o;
2346
2347                 if (!p->pack_local || p->pack_keep)
2348                         continue;
2349                 if (open_pack_index(p))
2350                         die("cannot open pack index");
2351
2352                 ALLOC_GROW(in_pack.array,
2353                            in_pack.nr + p->num_objects,
2354                            in_pack.alloc);
2355
2356                 for (i = 0; i < p->num_objects; i++) {
2357                         sha1 = nth_packed_object_sha1(p, i);
2358                         o = lookup_unknown_object(sha1);
2359                         if (!(o->flags & OBJECT_ADDED))
2360                                 mark_in_pack_object(o, p, &in_pack);
2361                         o->flags |= OBJECT_ADDED;
2362                 }
2363         }
2364
2365         if (in_pack.nr) {
2366                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
2367                       ofscmp);
2368                 for (i = 0; i < in_pack.nr; i++) {
2369                         struct object *o = in_pack.array[i].object;
2370                         add_object_entry(o->oid.hash, o->type, "", 0);
2371                 }
2372         }
2373         free(in_pack.array);
2374 }
2375
2376 static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2377 {
2378         static struct packed_git *last_found = (void *)1;
2379         struct packed_git *p;
2380
2381         p = (last_found != (void *)1) ? last_found : packed_git;
2382
2383         while (p) {
2384                 if ((!p->pack_local || p->pack_keep) &&
2385                         find_pack_entry_one(sha1, p)) {
2386                         last_found = p;
2387                         return 1;
2388                 }
2389                 if (p == last_found)
2390                         p = packed_git;
2391                 else
2392                         p = p->next;
2393                 if (p == last_found)
2394                         p = p->next;
2395         }
2396         return 0;
2397 }
2398
2399 /*
2400  * Store a list of sha1s that are should not be discarded
2401  * because they are either written too recently, or are
2402  * reachable from another object that was.
2403  *
2404  * This is filled by get_object_list.
2405  */
2406 static struct sha1_array recent_objects;
2407
2408 static int loosened_object_can_be_discarded(const unsigned char *sha1,
2409                                             unsigned long mtime)
2410 {
2411         if (!unpack_unreachable_expiration)
2412                 return 0;
2413         if (mtime > unpack_unreachable_expiration)
2414                 return 0;
2415         if (sha1_array_lookup(&recent_objects, sha1) >= 0)
2416                 return 0;
2417         return 1;
2418 }
2419
2420 static void loosen_unused_packed_objects(struct rev_info *revs)
2421 {
2422         struct packed_git *p;
2423         uint32_t i;
2424         const unsigned char *sha1;
2425
2426         for (p = packed_git; p; p = p->next) {
2427                 if (!p->pack_local || p->pack_keep)
2428                         continue;
2429
2430                 if (open_pack_index(p))
2431                         die("cannot open pack index");
2432
2433                 for (i = 0; i < p->num_objects; i++) {
2434                         sha1 = nth_packed_object_sha1(p, i);
2435                         if (!packlist_find(&to_pack, sha1, NULL) &&
2436                             !has_sha1_pack_kept_or_nonlocal(sha1) &&
2437                             !loosened_object_can_be_discarded(sha1, p->mtime))
2438                                 if (force_object_loose(sha1, p->mtime))
2439                                         die("unable to force loose object");
2440                 }
2441         }
2442 }
2443
2444 /*
2445  * This tracks any options which a reader of the pack might
2446  * not understand, and which would therefore prevent blind reuse
2447  * of what we have on disk.
2448  */
2449 static int pack_options_allow_reuse(void)
2450 {
2451         return allow_ofs_delta;
2452 }
2453
2454 static int get_object_list_from_bitmap(struct rev_info *revs)
2455 {
2456         if (prepare_bitmap_walk(revs) < 0)
2457                 return -1;
2458
2459         if (pack_options_allow_reuse() &&
2460             !reuse_partial_packfile_from_bitmap(
2461                         &reuse_packfile,
2462                         &reuse_packfile_objects,
2463                         &reuse_packfile_offset)) {
2464                 assert(reuse_packfile_objects);
2465                 nr_result += reuse_packfile_objects;
2466                 display_progress(progress_state, nr_result);
2467         }
2468
2469         traverse_bitmap_commit_list(&add_object_entry_from_bitmap);
2470         return 0;
2471 }
2472
2473 static void record_recent_object(struct object *obj,
2474                                  const char *name,
2475                                  void *data)
2476 {
2477         sha1_array_append(&recent_objects, obj->oid.hash);
2478 }
2479
2480 static void record_recent_commit(struct commit *commit, void *data)
2481 {
2482         sha1_array_append(&recent_objects, commit->object.oid.hash);
2483 }
2484
2485 static void get_object_list(int ac, const char **av)
2486 {
2487         struct rev_info revs;
2488         char line[1000];
2489         int flags = 0;
2490
2491         init_revisions(&revs, NULL);
2492         save_commit_buffer = 0;
2493         setup_revisions(ac, av, &revs, NULL);
2494
2495         /* make sure shallows are read */
2496         is_repository_shallow();
2497
2498         while (fgets(line, sizeof(line), stdin) != NULL) {
2499                 int len = strlen(line);
2500                 if (len && line[len - 1] == '\n')
2501                         line[--len] = 0;
2502                 if (!len)
2503                         break;
2504                 if (*line == '-') {
2505                         if (!strcmp(line, "--not")) {
2506                                 flags ^= UNINTERESTING;
2507                                 write_bitmap_index = 0;
2508                                 continue;
2509                         }
2510                         if (starts_with(line, "--shallow ")) {
2511                                 unsigned char sha1[20];
2512                                 if (get_sha1_hex(line + 10, sha1))
2513                                         die("not an SHA-1 '%s'", line + 10);
2514                                 register_shallow(sha1);
2515                                 use_bitmap_index = 0;
2516                                 continue;
2517                         }
2518                         die("not a rev '%s'", line);
2519                 }
2520                 if (handle_revision_arg(line, &revs, flags, REVARG_CANNOT_BE_FILENAME))
2521                         die("bad revision '%s'", line);
2522         }
2523
2524         if (use_bitmap_index && !get_object_list_from_bitmap(&revs))
2525                 return;
2526
2527         if (prepare_revision_walk(&revs))
2528                 die("revision walk setup failed");
2529         mark_edges_uninteresting(&revs, show_edge);
2530         traverse_commit_list(&revs, show_commit, show_object, NULL);
2531
2532         if (unpack_unreachable_expiration) {
2533                 revs.ignore_missing_links = 1;
2534                 if (add_unseen_recent_objects_to_traversal(&revs,
2535                                 unpack_unreachable_expiration))
2536                         die("unable to add recent objects");
2537                 if (prepare_revision_walk(&revs))
2538                         die("revision walk setup failed");
2539                 traverse_commit_list(&revs, record_recent_commit,
2540                                      record_recent_object, NULL);
2541         }
2542
2543         if (keep_unreachable)
2544                 add_objects_in_unpacked_packs(&revs);
2545         if (unpack_unreachable)
2546                 loosen_unused_packed_objects(&revs);
2547
2548         sha1_array_clear(&recent_objects);
2549 }
2550
2551 static int option_parse_index_version(const struct option *opt,
2552                                       const char *arg, int unset)
2553 {
2554         char *c;
2555         const char *val = arg;
2556         pack_idx_opts.version = strtoul(val, &c, 10);
2557         if (pack_idx_opts.version > 2)
2558                 die(_("unsupported index version %s"), val);
2559         if (*c == ',' && c[1])
2560                 pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
2561         if (*c || pack_idx_opts.off32_limit & 0x80000000)
2562                 die(_("bad index version '%s'"), val);
2563         return 0;
2564 }
2565
2566 static int option_parse_unpack_unreachable(const struct option *opt,
2567                                            const char *arg, int unset)
2568 {
2569         if (unset) {
2570                 unpack_unreachable = 0;
2571                 unpack_unreachable_expiration = 0;
2572         }
2573         else {
2574                 unpack_unreachable = 1;
2575                 if (arg)
2576                         unpack_unreachable_expiration = approxidate(arg);
2577         }
2578         return 0;
2579 }
2580
2581 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2582 {
2583         int use_internal_rev_list = 0;
2584         int thin = 0;
2585         int shallow = 0;
2586         int all_progress_implied = 0;
2587         struct argv_array rp = ARGV_ARRAY_INIT;
2588         int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
2589         int rev_list_index = 0;
2590         struct option pack_objects_options[] = {
2591                 OPT_SET_INT('q', "quiet", &progress,
2592                             N_("do not show progress meter"), 0),
2593                 OPT_SET_INT(0, "progress", &progress,
2594                             N_("show progress meter"), 1),
2595                 OPT_SET_INT(0, "all-progress", &progress,
2596                             N_("show progress meter during object writing phase"), 2),
2597                 OPT_BOOL(0, "all-progress-implied",
2598                          &all_progress_implied,
2599                          N_("similar to --all-progress when progress meter is shown")),
2600                 { OPTION_CALLBACK, 0, "index-version", NULL, N_("version[,offset]"),
2601                   N_("write the pack index file in the specified idx format version"),
2602                   0, option_parse_index_version },
2603                 OPT_MAGNITUDE(0, "max-pack-size", &pack_size_limit,
2604                               N_("maximum size of each output pack file")),
2605                 OPT_BOOL(0, "local", &local,
2606                          N_("ignore borrowed objects from alternate object store")),
2607                 OPT_BOOL(0, "incremental", &incremental,
2608                          N_("ignore packed objects")),
2609                 OPT_INTEGER(0, "window", &window,
2610                             N_("limit pack window by objects")),
2611                 OPT_MAGNITUDE(0, "window-memory", &window_memory_limit,
2612                               N_("limit pack window by memory in addition to object limit")),
2613                 OPT_INTEGER(0, "depth", &depth,
2614                             N_("maximum length of delta chain allowed in the resulting pack")),
2615                 OPT_BOOL(0, "reuse-delta", &reuse_delta,
2616                          N_("reuse existing deltas")),
2617                 OPT_BOOL(0, "reuse-object", &reuse_object,
2618                          N_("reuse existing objects")),
2619                 OPT_BOOL(0, "delta-base-offset", &allow_ofs_delta,
2620                          N_("use OFS_DELTA objects")),
2621                 OPT_INTEGER(0, "threads", &delta_search_threads,
2622                             N_("use threads when searching for best delta matches")),
2623                 OPT_BOOL(0, "non-empty", &non_empty,
2624                          N_("do not create an empty pack output")),
2625                 OPT_BOOL(0, "revs", &use_internal_rev_list,
2626                          N_("read revision arguments from standard input")),
2627                 { OPTION_SET_INT, 0, "unpacked", &rev_list_unpacked, NULL,
2628                   N_("limit the objects to those that are not yet packed"),
2629                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2630                 { OPTION_SET_INT, 0, "all", &rev_list_all, NULL,
2631                   N_("include objects reachable from any reference"),
2632                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2633                 { OPTION_SET_INT, 0, "reflog", &rev_list_reflog, NULL,
2634                   N_("include objects referred by reflog entries"),
2635                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2636                 { OPTION_SET_INT, 0, "indexed-objects", &rev_list_index, NULL,
2637                   N_("include objects referred to by the index"),
2638                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2639                 OPT_BOOL(0, "stdout", &pack_to_stdout,
2640                          N_("output pack to stdout")),
2641                 OPT_BOOL(0, "include-tag", &include_tag,
2642                          N_("include tag objects that refer to objects to be packed")),
2643                 OPT_BOOL(0, "keep-unreachable", &keep_unreachable,
2644                          N_("keep unreachable objects")),
2645                 { OPTION_CALLBACK, 0, "unpack-unreachable", NULL, N_("time"),
2646                   N_("unpack unreachable objects newer than <time>"),
2647                   PARSE_OPT_OPTARG, option_parse_unpack_unreachable },
2648                 OPT_BOOL(0, "thin", &thin,
2649                          N_("create thin packs")),
2650                 OPT_BOOL(0, "shallow", &shallow,
2651                          N_("create packs suitable for shallow fetches")),
2652                 OPT_BOOL(0, "honor-pack-keep", &ignore_packed_keep,
2653                          N_("ignore packs that have companion .keep file")),
2654                 OPT_INTEGER(0, "compression", &pack_compression_level,
2655                             N_("pack compression level")),
2656                 OPT_SET_INT(0, "keep-true-parents", &grafts_replace_parents,
2657                             N_("do not hide commits by grafts"), 0),
2658                 OPT_BOOL(0, "use-bitmap-index", &use_bitmap_index,
2659                          N_("use a bitmap index if available to speed up counting objects")),
2660                 OPT_BOOL(0, "write-bitmap-index", &write_bitmap_index,
2661                          N_("write a bitmap index together with the pack index")),
2662                 OPT_END(),
2663         };
2664
2665         check_replace_refs = 0;
2666
2667         reset_pack_idx_option(&pack_idx_opts);
2668         git_config(git_pack_config, NULL);
2669         if (!pack_compression_seen && core_compression_seen)
2670                 pack_compression_level = core_compression_level;
2671
2672         progress = isatty(2);
2673         argc = parse_options(argc, argv, prefix, pack_objects_options,
2674                              pack_usage, 0);
2675
2676         if (argc) {
2677                 base_name = argv[0];
2678                 argc--;
2679         }
2680         if (pack_to_stdout != !base_name || argc)
2681                 usage_with_options(pack_usage, pack_objects_options);
2682
2683         argv_array_push(&rp, "pack-objects");
2684         if (thin) {
2685                 use_internal_rev_list = 1;
2686                 argv_array_push(&rp, shallow
2687                                 ? "--objects-edge-aggressive"
2688                                 : "--objects-edge");
2689         } else
2690                 argv_array_push(&rp, "--objects");
2691
2692         if (rev_list_all) {
2693                 use_internal_rev_list = 1;
2694                 argv_array_push(&rp, "--all");
2695         }
2696         if (rev_list_reflog) {
2697                 use_internal_rev_list = 1;
2698                 argv_array_push(&rp, "--reflog");
2699         }
2700         if (rev_list_index) {
2701                 use_internal_rev_list = 1;
2702                 argv_array_push(&rp, "--indexed-objects");
2703         }
2704         if (rev_list_unpacked) {
2705                 use_internal_rev_list = 1;
2706                 argv_array_push(&rp, "--unpacked");
2707         }
2708
2709         if (!reuse_object)
2710                 reuse_delta = 0;
2711         if (pack_compression_level == -1)
2712                 pack_compression_level = Z_DEFAULT_COMPRESSION;
2713         else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
2714                 die("bad pack compression level %d", pack_compression_level);
2715
2716         if (!delta_search_threads)      /* --threads=0 means autodetect */
2717                 delta_search_threads = online_cpus();
2718
2719 #ifdef NO_PTHREADS
2720         if (delta_search_threads != 1)
2721                 warning("no threads support, ignoring --threads");
2722 #endif
2723         if (!pack_to_stdout && !pack_size_limit)
2724                 pack_size_limit = pack_size_limit_cfg;
2725         if (pack_to_stdout && pack_size_limit)
2726                 die("--max-pack-size cannot be used to build a pack for transfer.");
2727         if (pack_size_limit && pack_size_limit < 1024*1024) {
2728                 warning("minimum pack size limit is 1 MiB");
2729                 pack_size_limit = 1024*1024;
2730         }
2731
2732         if (!pack_to_stdout && thin)
2733                 die("--thin cannot be used to build an indexable pack.");
2734
2735         if (keep_unreachable && unpack_unreachable)
2736                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2737         if (!rev_list_all || !rev_list_reflog || !rev_list_index)
2738                 unpack_unreachable_expiration = 0;
2739
2740         if (!use_internal_rev_list || !pack_to_stdout || is_repository_shallow())
2741                 use_bitmap_index = 0;
2742
2743         if (pack_to_stdout || !rev_list_all)
2744                 write_bitmap_index = 0;
2745
2746         if (progress && all_progress_implied)
2747                 progress = 2;
2748
2749         prepare_packed_git();
2750
2751         if (progress)
2752                 progress_state = start_progress(_("Counting objects"), 0);
2753         if (!use_internal_rev_list)
2754                 read_object_list_from_stdin();
2755         else {
2756                 get_object_list(rp.argc, rp.argv);
2757                 argv_array_clear(&rp);
2758         }
2759         cleanup_preferred_base();
2760         if (include_tag && nr_result)
2761                 for_each_ref(add_ref_tag, NULL);
2762         stop_progress(&progress_state);
2763
2764         if (non_empty && !nr_result)
2765                 return 0;
2766         if (nr_result)
2767                 prepare_pack(window, depth);
2768         write_pack_file();
2769         if (progress)
2770                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2771                         " reused %"PRIu32" (delta %"PRIu32")\n",
2772                         written, written_delta, reused, reused_delta);
2773         return 0;
2774 }