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 const char no_split_warning[] = N_(
 763 "disabling bitmap writing, packs are split due to pack.packSizeLimit"
 764 );
 765
 766 static void write_pack_file(void)
 767 {
 768         uint32_t i = 0, j;
 769         struct sha1file *f;
 770         off_t offset;
 771         uint32_t nr_remaining = nr_result;
 772         time_t last_mtime = 0;
 773         struct object_entry **write_order;
 774
 775         if (progress > pack_to_stdout)
 776                 progress_state = start_progress(_("Writing objects"), nr_result);
 777         ALLOC_ARRAY(written_list, to_pack.nr_objects);
 778         write_order = compute_write_order();
 779
 780         do {
 781                 unsigned char sha1[20];
 782                 char *pack_tmp_name = NULL;
 783
 784                 if (pack_to_stdout)
 785                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 786                 else
 787                         f = create_tmp_packfile(&pack_tmp_name);
 788
 789                 offset = write_pack_header(f, nr_remaining);
 790
 791                 if (reuse_packfile) {
 792                         off_t packfile_size;
 793                         assert(pack_to_stdout);
 794
 795                         packfile_size = write_reused_pack(f);
 796                         offset += packfile_size;
 797                 }
 798
 799                 nr_written = 0;
 800                 for (; i < to_pack.nr_objects; i++) {
 801                         struct object_entry *e = write_order[i];
 802                         if (write_one(f, e, &offset) == WRITE_ONE_BREAK)
 803                                 break;
 804                         display_progress(progress_state, written);
 805                 }
 806
 807                 /*
 808                  * Did we write the wrong # entries in the header?
 809                  * If so, rewrite it like in fast-import
 810                  */
 811                 if (pack_to_stdout) {
 812                         sha1close(f, sha1, CSUM_CLOSE);
 813                 } else if (nr_written == nr_remaining) {
 814                         sha1close(f, sha1, CSUM_FSYNC);
 815                 } else {
 816                         int fd = sha1close(f, sha1, 0);
 817                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
 818                                                  nr_written, sha1, offset);
 819                         close(fd);
 820                         if (write_bitmap_index) {
 821                                 warning(_(no_split_warning));
 822                                 write_bitmap_index = 0;
 823                         }
 824                 }
 825
 826                 if (!pack_to_stdout) {
 827                         struct stat st;
 828                         struct strbuf tmpname = STRBUF_INIT;
 829
 830                         /*
 831                          * Packs are runtime accessed in their mtime
 832                          * order since newer packs are more likely to contain
 833                          * younger objects.  So if we are creating multiple
 834                          * packs then we should modify the mtime of later ones
 835                          * to preserve this property.
 836                          */
 837                         if (stat(pack_tmp_name, &st) < 0) {
 838                                 warning_errno("failed to stat %s", pack_tmp_name);
 839                         } else if (!last_mtime) {
 840                                 last_mtime = st.st_mtime;
 841                         } else {
 842                                 struct utimbuf utb;
 843                                 utb.actime = st.st_atime;
 844                                 utb.modtime = --last_mtime;
 845                                 if (utime(pack_tmp_name, &utb) < 0)
 846                                         warning_errno("failed utime() on %s", pack_tmp_name);
 847                         }
 848
 849                         strbuf_addf(&tmpname, "%s-", base_name);
 850
 851                         if (write_bitmap_index) {
 852                                 bitmap_writer_set_checksum(sha1);
 853                                 bitmap_writer_build_type_index(written_list, nr_written);
 854                         }
 855
 856                         finish_tmp_packfile(&tmpname, pack_tmp_name,
 857                                             written_list, nr_written,
 858                                             &pack_idx_opts, sha1);
 859
 860                         if (write_bitmap_index) {
 861                                 strbuf_addf(&tmpname, "%s.bitmap", sha1_to_hex(sha1));
 862
 863                                 stop_progress(&progress_state);
 864
 865                                 bitmap_writer_show_progress(progress);
 866                                 bitmap_writer_reuse_bitmaps(&to_pack);
 867                                 bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
 868                                 bitmap_writer_build(&to_pack);
 869                                 bitmap_writer_finish(written_list, nr_written,
 870                                                      tmpname.buf, write_bitmap_options);
 871                                 write_bitmap_index = 0;
 872                         }
 873
 874                         strbuf_release(&tmpname);
 875                         free(pack_tmp_name);
 876                         puts(sha1_to_hex(sha1));
 877                 }
 878
 879                 /* mark written objects as written to previous pack */
 880                 for (j = 0; j < nr_written; j++) {
 881                         written_list[j]->offset = (off_t)-1;
 882                 }
 883                 nr_remaining -= nr_written;
 884         } while (nr_remaining && i < to_pack.nr_objects);
 885
 886         free(written_list);
 887         free(write_order);
 888         stop_progress(&progress_state);
 889         if (written != nr_result)
 890                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
 891                         written, nr_result);
 892 }
 893
 894 static void setup_delta_attr_check(struct git_attr_check *check)
 895 {
 896         static struct git_attr *attr_delta;
 897
 898         if (!attr_delta)
 899                 attr_delta = git_attr("delta");
 900
 901         check[0].attr = attr_delta;
 902 }
 903
 904 static int no_try_delta(const char *path)
 905 {
 906         struct git_attr_check check[1];
 907
 908         setup_delta_attr_check(check);
 909         if (git_check_attr(path, ARRAY_SIZE(check), check))
 910                 return 0;
 911         if (ATTR_FALSE(check->value))
 912                 return 1;
 913         return 0;
 914 }
 915
 916 /*
 917  * When adding an object, check whether we have already added it
 918  * to our packing list. If so, we can skip. However, if we are
 919  * being asked to excludei t, but the previous mention was to include
 920  * it, make sure to adjust its flags and tweak our numbers accordingly.
 921  *
 922  * As an optimization, we pass out the index position where we would have
 923  * found the item, since that saves us from having to look it up again a
 924  * few lines later when we want to add the new entry.
 925  */
 926 static int have_duplicate_entry(const unsigned char *sha1,
 927                                 int exclude,
 928                                 uint32_t *index_pos)
 929 {
 930         struct object_entry *entry;
 931
 932         entry = packlist_find(&to_pack, sha1, index_pos);
 933         if (!entry)
 934                 return 0;
 935
 936         if (exclude) {
 937                 if (!entry->preferred_base)
 938                         nr_result--;
 939                 entry->preferred_base = 1;
 940         }
 941
 942         return 1;
 943 }
 944
 945 /*
 946  * Check whether we want the object in the pack (e.g., we do not want
 947  * objects found in non-local stores if the "--local" option was used).
 948  *
 949  * As a side effect of this check, we will find the packed version of this
 950  * object, if any. We therefore pass out the pack information to avoid having
 951  * to look it up again later.
 952  */
 953 static int want_object_in_pack(const unsigned char *sha1,
 954                                int exclude,
 955                                struct packed_git **found_pack,
 956                                off_t *found_offset)
 957 {
 958         struct packed_git *p;
 959
 960         if (!exclude && local && has_loose_object_nonlocal(sha1))
 961                 return 0;
 962
 963         *found_pack = NULL;
 964         *found_offset = 0;
 965
 966         for (p = packed_git; p; p = p->next) {
 967                 off_t offset = find_pack_entry_one(sha1, p);
 968                 if (offset) {
 969                         if (!*found_pack) {
 970                                 if (!is_pack_valid(p))
 971                                         continue;
 972                                 *found_offset = offset;
 973                                 *found_pack = p;
 974                         }
 975                         if (exclude)
 976                                 return 1;
 977                         if (incremental)
 978                                 return 0;
 979                         if (local && !p->pack_local)
 980                                 return 0;
 981                         if (ignore_packed_keep && p->pack_local && p->pack_keep)
 982                                 return 0;
 983                 }
 984         }
 985
 986         return 1;
 987 }
 988
 989 static void create_object_entry(const unsigned char *sha1,
 990                                 enum object_type type,
 991                                 uint32_t hash,
 992                                 int exclude,
 993                                 int no_try_delta,
 994                                 uint32_t index_pos,
 995                                 struct packed_git *found_pack,
 996                                 off_t found_offset)
 997 {
 998         struct object_entry *entry;
 999
1000         entry = packlist_alloc(&to_pack, sha1, index_pos);
1001         entry->hash = hash;
1002         if (type)
1003                 entry->type = type;
1004         if (exclude)
1005                 entry->preferred_base = 1;
1006         else
1007                 nr_result++;
1008         if (found_pack) {
1009                 entry->in_pack = found_pack;
1010                 entry->in_pack_offset = found_offset;
1011         }
1012
1013         entry->no_try_delta = no_try_delta;
1014 }
1015
1016 static const char no_closure_warning[] = N_(
1017 "disabling bitmap writing, as some objects are not being packed"
1018 );
1019
1020 static int add_object_entry(const unsigned char *sha1, enum object_type type,
1021                             const char *name, int exclude)
1022 {
1023         struct packed_git *found_pack;
1024         off_t found_offset;
1025         uint32_t index_pos;
1026
1027         if (have_duplicate_entry(sha1, exclude, &index_pos))
1028                 return 0;
1029
1030         if (!want_object_in_pack(sha1, exclude, &found_pack, &found_offset)) {
1031                 /* The pack is missing an object, so it will not have closure */
1032                 if (write_bitmap_index) {
1033                         warning(_(no_closure_warning));
1034                         write_bitmap_index = 0;
1035                 }
1036                 return 0;
1037         }
1038
1039         create_object_entry(sha1, type, pack_name_hash(name),
1040                             exclude, name && no_try_delta(name),
1041                             index_pos, found_pack, found_offset);
1042
1043         display_progress(progress_state, nr_result);
1044         return 1;
1045 }
1046
1047 static int add_object_entry_from_bitmap(const unsigned char *sha1,
1048                                         enum object_type type,
1049                                         int flags, uint32_t name_hash,
1050                                         struct packed_git *pack, off_t offset)
1051 {
1052         uint32_t index_pos;
1053
1054         if (have_duplicate_entry(sha1, 0, &index_pos))
1055                 return 0;
1056
1057         create_object_entry(sha1, type, name_hash, 0, 0, index_pos, pack, offset);
1058
1059         display_progress(progress_state, nr_result);
1060         return 1;
1061 }
1062
1063 struct pbase_tree_cache {
1064         unsigned char sha1[20];
1065         int ref;
1066         int temporary;
1067         void *tree_data;
1068         unsigned long tree_size;
1069 };
1070
1071 static struct pbase_tree_cache *(pbase_tree_cache[256]);
1072 static int pbase_tree_cache_ix(const unsigned char *sha1)
1073 {
1074         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
1075 }
1076 static int pbase_tree_cache_ix_incr(int ix)
1077 {
1078         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
1079 }
1080
1081 static struct pbase_tree {
1082         struct pbase_tree *next;
1083         /* This is a phony "cache" entry; we are not
1084          * going to evict it or find it through _get()
1085          * mechanism -- this is for the toplevel node that
1086          * would almost always change with any commit.
1087          */
1088         struct pbase_tree_cache pcache;
1089 } *pbase_tree;
1090
1091 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
1092 {
1093         struct pbase_tree_cache *ent, *nent;
1094         void *data;
1095         unsigned long size;
1096         enum object_type type;
1097         int neigh;
1098         int my_ix = pbase_tree_cache_ix(sha1);
1099         int available_ix = -1;
1100
1101         /* pbase-tree-cache acts as a limited hashtable.
1102          * your object will be found at your index or within a few
1103          * slots after that slot if it is cached.
1104          */
1105         for (neigh = 0; neigh < 8; neigh++) {
1106                 ent = pbase_tree_cache[my_ix];
1107                 if (ent && !hashcmp(ent->sha1, sha1)) {
1108                         ent->ref++;
1109                         return ent;
1110                 }
1111                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
1112                          ((0 <= available_ix) &&
1113                           (!ent && pbase_tree_cache[available_ix])))
1114                         available_ix = my_ix;
1115                 if (!ent)
1116                         break;
1117                 my_ix = pbase_tree_cache_ix_incr(my_ix);
1118         }
1119
1120         /* Did not find one.  Either we got a bogus request or
1121          * we need to read and perhaps cache.
1122          */
1123         data = read_sha1_file(sha1, &type, &size);
1124         if (!data)
1125                 return NULL;
1126         if (type != OBJ_TREE) {
1127                 free(data);
1128                 return NULL;
1129         }
1130
1131         /* We need to either cache or return a throwaway copy */
1132
1133         if (available_ix < 0)
1134                 ent = NULL;
1135         else {
1136                 ent = pbase_tree_cache[available_ix];
1137                 my_ix = available_ix;
1138         }
1139
1140         if (!ent) {
1141                 nent = xmalloc(sizeof(*nent));
1142                 nent->temporary = (available_ix < 0);
1143         }
1144         else {
1145                 /* evict and reuse */
1146                 free(ent->tree_data);
1147                 nent = ent;
1148         }
1149         hashcpy(nent->sha1, sha1);
1150         nent->tree_data = data;
1151         nent->tree_size = size;
1152         nent->ref = 1;
1153         if (!nent->temporary)
1154                 pbase_tree_cache[my_ix] = nent;
1155         return nent;
1156 }
1157
1158 static void pbase_tree_put(struct pbase_tree_cache *cache)
1159 {
1160         if (!cache->temporary) {
1161                 cache->ref--;
1162                 return;
1163         }
1164         free(cache->tree_data);
1165         free(cache);
1166 }
1167
1168 static int name_cmp_len(const char *name)
1169 {
1170         int i;
1171         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
1172                 ;
1173         return i;
1174 }
1175
1176 static void add_pbase_object(struct tree_desc *tree,
1177                              const char *name,
1178                              int cmplen,
1179                              const char *fullname)
1180 {
1181         struct name_entry entry;
1182         int cmp;
1183
1184         while (tree_entry(tree,&entry)) {
1185                 if (S_ISGITLINK(entry.mode))
1186                         continue;
1187                 cmp = tree_entry_len(&entry) != cmplen ? 1 :
1188                       memcmp(name, entry.path, cmplen);
1189                 if (cmp > 0)
1190                         continue;
1191                 if (cmp < 0)
1192                         return;
1193                 if (name[cmplen] != '/') {
1194                         add_object_entry(entry.oid->hash,
1195                                          object_type(entry.mode),
1196                                          fullname, 1);
1197                         return;
1198                 }
1199                 if (S_ISDIR(entry.mode)) {
1200                         struct tree_desc sub;
1201                         struct pbase_tree_cache *tree;
1202                         const char *down = name+cmplen+1;
1203                         int downlen = name_cmp_len(down);
1204
1205                         tree = pbase_tree_get(entry.oid->hash);
1206                         if (!tree)
1207                                 return;
1208                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1209
1210                         add_pbase_object(&sub, down, downlen, fullname);
1211                         pbase_tree_put(tree);
1212                 }
1213         }
1214 }
1215
1216 static unsigned *done_pbase_paths;
1217 static int done_pbase_paths_num;
1218 static int done_pbase_paths_alloc;
1219 static int done_pbase_path_pos(unsigned hash)
1220 {
1221         int lo = 0;
1222         int hi = done_pbase_paths_num;
1223         while (lo < hi) {
1224                 int mi = (hi + lo) / 2;
1225                 if (done_pbase_paths[mi] == hash)
1226                         return mi;
1227                 if (done_pbase_paths[mi] < hash)
1228                         hi = mi;
1229                 else
1230                         lo = mi + 1;
1231         }
1232         return -lo-1;
1233 }
1234
1235 static int check_pbase_path(unsigned hash)
1236 {
1237         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
1238         if (0 <= pos)
1239                 return 1;
1240         pos = -pos - 1;
1241         ALLOC_GROW(done_pbase_paths,
1242                    done_pbase_paths_num + 1,
1243                    done_pbase_paths_alloc);
1244         done_pbase_paths_num++;
1245         if (pos < done_pbase_paths_num)
1246                 memmove(done_pbase_paths + pos + 1,
1247                         done_pbase_paths + pos,
1248                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
1249         done_pbase_paths[pos] = hash;
1250         return 0;
1251 }
1252
1253 static void add_preferred_base_object(const char *name)
1254 {
1255         struct pbase_tree *it;
1256         int cmplen;
1257         unsigned hash = pack_name_hash(name);
1258
1259         if (!num_preferred_base || check_pbase_path(hash))
1260                 return;
1261
1262         cmplen = name_cmp_len(name);
1263         for (it = pbase_tree; it; it = it->next) {
1264                 if (cmplen == 0) {
1265                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
1266                 }
1267                 else {
1268                         struct tree_desc tree;
1269                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1270                         add_pbase_object(&tree, name, cmplen, name);
1271                 }
1272         }
1273 }
1274
1275 static void add_preferred_base(unsigned char *sha1)
1276 {
1277         struct pbase_tree *it;
1278         void *data;
1279         unsigned long size;
1280         unsigned char tree_sha1[20];
1281
1282         if (window <= num_preferred_base++)
1283                 return;
1284
1285         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
1286         if (!data)
1287                 return;
1288
1289         for (it = pbase_tree; it; it = it->next) {
1290                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
1291                         free(data);
1292                         return;
1293                 }
1294         }
1295
1296         it = xcalloc(1, sizeof(*it));
1297         it->next = pbase_tree;
1298         pbase_tree = it;
1299
1300         hashcpy(it->pcache.sha1, tree_sha1);
1301         it->pcache.tree_data = data;
1302         it->pcache.tree_size = size;
1303 }
1304
1305 static void cleanup_preferred_base(void)
1306 {
1307         struct pbase_tree *it;
1308         unsigned i;
1309
1310         it = pbase_tree;
1311         pbase_tree = NULL;
1312         while (it) {
1313                 struct pbase_tree *this = it;
1314                 it = this->next;
1315                 free(this->pcache.tree_data);
1316                 free(this);
1317         }
1318
1319         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1320                 if (!pbase_tree_cache[i])
1321                         continue;
1322                 free(pbase_tree_cache[i]->tree_data);
1323                 free(pbase_tree_cache[i]);
1324                 pbase_tree_cache[i] = NULL;
1325         }
1326
1327         free(done_pbase_paths);
1328         done_pbase_paths = NULL;
1329         done_pbase_paths_num = done_pbase_paths_alloc = 0;
1330 }
1331
1332 static void check_object(struct object_entry *entry)
1333 {
1334         if (entry->in_pack) {
1335                 struct packed_git *p = entry->in_pack;
1336                 struct pack_window *w_curs = NULL;
1337                 const unsigned char *base_ref = NULL;
1338                 struct object_entry *base_entry;
1339                 unsigned long used, used_0;
1340                 unsigned long avail;
1341                 off_t ofs;
1342                 unsigned char *buf, c;
1343
1344                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1345
1346                 /*
1347                  * We want in_pack_type even if we do not reuse delta
1348                  * since non-delta representations could still be reused.
1349                  */
1350                 used = unpack_object_header_buffer(buf, avail,
1351                                                    &entry->in_pack_type,
1352                                                    &entry->size);
1353                 if (used == 0)
1354                         goto give_up;
1355
1356                 /*
1357                  * Determine if this is a delta and if so whether we can
1358                  * reuse it or not.  Otherwise let's find out as cheaply as
1359                  * possible what the actual type and size for this object is.
1360                  */
1361                 switch (entry->in_pack_type) {
1362                 default:
1363                         /* Not a delta hence we've already got all we need. */
1364                         entry->type = entry->in_pack_type;
1365                         entry->in_pack_header_size = used;
1366                         if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1367                                 goto give_up;
1368                         unuse_pack(&w_curs);
1369                         return;
1370                 case OBJ_REF_DELTA:
1371                         if (reuse_delta && !entry->preferred_base)
1372                                 base_ref = use_pack(p, &w_curs,
1373                                                 entry->in_pack_offset + used, NULL);
1374                         entry->in_pack_header_size = used + 20;
1375                         break;
1376                 case OBJ_OFS_DELTA:
1377                         buf = use_pack(p, &w_curs,
1378                                        entry->in_pack_offset + used, NULL);
1379                         used_0 = 0;
1380                         c = buf[used_0++];
1381                         ofs = c & 127;
1382                         while (c & 128) {
1383                                 ofs += 1;
1384                                 if (!ofs || MSB(ofs, 7)) {
1385                                         error("delta base offset overflow in pack for %s",
1386                                               sha1_to_hex(entry->idx.sha1));
1387                                         goto give_up;
1388                                 }
1389                                 c = buf[used_0++];
1390                                 ofs = (ofs << 7) + (c & 127);
1391                         }
1392                         ofs = entry->in_pack_offset - ofs;
1393                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1394                                 error("delta base offset out of bound for %s",
1395                                       sha1_to_hex(entry->idx.sha1));
1396                                 goto give_up;
1397                         }
1398                         if (reuse_delta && !entry->preferred_base) {
1399                                 struct revindex_entry *revidx;
1400                                 revidx = find_pack_revindex(p, ofs);
1401                                 if (!revidx)
1402                                         goto give_up;
1403                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1404                         }
1405                         entry->in_pack_header_size = used + used_0;
1406                         break;
1407                 }
1408
1409                 if (base_ref && (base_entry = packlist_find(&to_pack, base_ref, NULL))) {
1410                         /*
1411                          * If base_ref was set above that means we wish to
1412                          * reuse delta data, and we even found that base
1413                          * in the list of objects we want to pack. Goodie!
1414                          *
1415                          * Depth value does not matter - find_deltas() will
1416                          * never consider reused delta as the base object to
1417                          * deltify other objects against, in order to avoid
1418                          * circular deltas.
1419                          */
1420                         entry->type = entry->in_pack_type;
1421                         entry->delta = base_entry;
1422                         entry->delta_size = entry->size;
1423                         entry->delta_sibling = base_entry->delta_child;
1424                         base_entry->delta_child = entry;
1425                         unuse_pack(&w_curs);
1426                         return;
1427                 }
1428
1429                 if (entry->type) {
1430                         /*
1431                          * This must be a delta and we already know what the
1432                          * final object type is.  Let's extract the actual
1433                          * object size from the delta header.
1434                          */
1435                         entry->size = get_size_from_delta(p, &w_curs,
1436                                         entry->in_pack_offset + entry->in_pack_header_size);
1437                         if (entry->size == 0)
1438                                 goto give_up;
1439                         unuse_pack(&w_curs);
1440                         return;
1441                 }
1442
1443                 /*
1444                  * No choice but to fall back to the recursive delta walk
1445                  * with sha1_object_info() to find about the object type
1446                  * at this point...
1447                  */
1448                 give_up:
1449                 unuse_pack(&w_curs);
1450         }
1451
1452         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1453         /*
1454          * The error condition is checked in prepare_pack().  This is
1455          * to permit a missing preferred base object to be ignored
1456          * as a preferred base.  Doing so can result in a larger
1457          * pack file, but the transfer will still take place.
1458          */
1459 }
1460
1461 static int pack_offset_sort(const void *_a, const void *_b)
1462 {
1463         const struct object_entry *a = *(struct object_entry **)_a;
1464         const struct object_entry *b = *(struct object_entry **)_b;
1465
1466         /* avoid filesystem trashing with loose objects */
1467         if (!a->in_pack && !b->in_pack)
1468                 return hashcmp(a->idx.sha1, b->idx.sha1);
1469
1470         if (a->in_pack < b->in_pack)
1471                 return -1;
1472         if (a->in_pack > b->in_pack)
1473                 return 1;
1474         return a->in_pack_offset < b->in_pack_offset ? -1 :
1475                         (a->in_pack_offset > b->in_pack_offset);
1476 }
1477
1478 static void get_object_details(void)
1479 {
1480         uint32_t i;
1481         struct object_entry **sorted_by_offset;
1482
1483         sorted_by_offset = xcalloc(to_pack.nr_objects, sizeof(struct object_entry *));
1484         for (i = 0; i < to_pack.nr_objects; i++)
1485                 sorted_by_offset[i] = to_pack.objects + i;
1486         qsort(sorted_by_offset, to_pack.nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1487
1488         for (i = 0; i < to_pack.nr_objects; i++) {
1489                 struct object_entry *entry = sorted_by_offset[i];
1490                 check_object(entry);
1491                 if (big_file_threshold < entry->size)
1492                         entry->no_try_delta = 1;
1493         }
1494
1495         free(sorted_by_offset);
1496 }
1497
1498 /*
1499  * We search for deltas in a list sorted by type, by filename hash, and then
1500  * by size, so that we see progressively smaller and smaller files.
1501  * That's because we prefer deltas to be from the bigger file
1502  * to the smaller -- deletes are potentially cheaper, but perhaps
1503  * more importantly, the bigger file is likely the more recent
1504  * one.  The deepest deltas are therefore the oldest objects which are
1505  * less susceptible to be accessed often.
1506  */
1507 static int type_size_sort(const void *_a, const void *_b)
1508 {
1509         const struct object_entry *a = *(struct object_entry **)_a;
1510         const struct object_entry *b = *(struct object_entry **)_b;
1511
1512         if (a->type > b->type)
1513                 return -1;
1514         if (a->type < b->type)
1515                 return 1;
1516         if (a->hash > b->hash)
1517                 return -1;
1518         if (a->hash < b->hash)
1519                 return 1;
1520         if (a->preferred_base > b->preferred_base)
1521                 return -1;
1522         if (a->preferred_base < b->preferred_base)
1523                 return 1;
1524         if (a->size > b->size)
1525                 return -1;
1526         if (a->size < b->size)
1527                 return 1;
1528         return a < b ? -1 : (a > b);  /* newest first */
1529 }
1530
1531 struct unpacked {
1532         struct object_entry *entry;
1533         void *data;
1534         struct delta_index *index;
1535         unsigned depth;
1536 };
1537
1538 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1539                            unsigned long delta_size)
1540 {
1541         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1542                 return 0;
1543
1544         if (delta_size < cache_max_small_delta_size)
1545                 return 1;
1546
1547         /* cache delta, if objects are large enough compared to delta size */
1548         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1549                 return 1;
1550
1551         return 0;
1552 }
1553
1554 #ifndef NO_PTHREADS
1555
1556 static pthread_mutex_t read_mutex;
1557 #define read_lock()             pthread_mutex_lock(&read_mutex)
1558 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1559
1560 static pthread_mutex_t cache_mutex;
1561 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1562 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1563
1564 static pthread_mutex_t progress_mutex;
1565 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1566 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1567
1568 #else
1569
1570 #define read_lock()             (void)0
1571 #define read_unlock()           (void)0
1572 #define cache_lock()            (void)0
1573 #define cache_unlock()          (void)0
1574 #define progress_lock()         (void)0
1575 #define progress_unlock()       (void)0
1576
1577 #endif
1578
1579 static int try_delta(struct unpacked *trg, struct unpacked *src,
1580                      unsigned max_depth, unsigned long *mem_usage)
1581 {
1582         struct object_entry *trg_entry = trg->entry;
1583         struct object_entry *src_entry = src->entry;
1584         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1585         unsigned ref_depth;
1586         enum object_type type;
1587         void *delta_buf;
1588
1589         /* Don't bother doing diffs between different types */
1590         if (trg_entry->type != src_entry->type)
1591                 return -1;
1592
1593         /*
1594          * We do not bother to try a delta that we discarded on an
1595          * earlier try, but only when reusing delta data.  Note that
1596          * src_entry that is marked as the preferred_base should always
1597          * be considered, as even if we produce a suboptimal delta against
1598          * it, we will still save the transfer cost, as we already know
1599          * the other side has it and we won't send src_entry at all.
1600          */
1601         if (reuse_delta && trg_entry->in_pack &&
1602             trg_entry->in_pack == src_entry->in_pack &&
1603             !src_entry->preferred_base &&
1604             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1605             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1606                 return 0;
1607
1608         /* Let's not bust the allowed depth. */
1609         if (src->depth >= max_depth)
1610                 return 0;
1611
1612         /* Now some size filtering heuristics. */
1613         trg_size = trg_entry->size;
1614         if (!trg_entry->delta) {
1615                 max_size = trg_size/2 - 20;
1616                 ref_depth = 1;
1617         } else {
1618                 max_size = trg_entry->delta_size;
1619                 ref_depth = trg->depth;
1620         }
1621         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1622                                                 (max_depth - ref_depth + 1);
1623         if (max_size == 0)
1624                 return 0;
1625         src_size = src_entry->size;
1626         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1627         if (sizediff >= max_size)
1628                 return 0;
1629         if (trg_size < src_size / 32)
1630                 return 0;
1631
1632         /* Load data if not already done */
1633         if (!trg->data) {
1634                 read_lock();
1635                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1636                 read_unlock();
1637                 if (!trg->data)
1638                         die("object %s cannot be read",
1639                             sha1_to_hex(trg_entry->idx.sha1));
1640                 if (sz != trg_size)
1641                         die("object %s inconsistent object length (%lu vs %lu)",
1642                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1643                 *mem_usage += sz;
1644         }
1645         if (!src->data) {
1646                 read_lock();
1647                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1648                 read_unlock();
1649                 if (!src->data) {
1650                         if (src_entry->preferred_base) {
1651                                 static int warned = 0;
1652                                 if (!warned++)
1653                                         warning("object %s cannot be read",
1654                                                 sha1_to_hex(src_entry->idx.sha1));
1655                                 /*
1656                                  * Those objects are not included in the
1657                                  * resulting pack.  Be resilient and ignore
1658                                  * them if they can't be read, in case the
1659                                  * pack could be created nevertheless.
1660                                  */
1661                                 return 0;
1662                         }
1663                         die("object %s cannot be read",
1664                             sha1_to_hex(src_entry->idx.sha1));
1665                 }
1666                 if (sz != src_size)
1667                         die("object %s inconsistent object length (%lu vs %lu)",
1668                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1669                 *mem_usage += sz;
1670         }
1671         if (!src->index) {
1672                 src->index = create_delta_index(src->data, src_size);
1673                 if (!src->index) {
1674                         static int warned = 0;
1675                         if (!warned++)
1676                                 warning("suboptimal pack - out of memory");
1677                         return 0;
1678                 }
1679                 *mem_usage += sizeof_delta_index(src->index);
1680         }
1681
1682         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1683         if (!delta_buf)
1684                 return 0;
1685
1686         if (trg_entry->delta) {
1687                 /* Prefer only shallower same-sized deltas. */
1688                 if (delta_size == trg_entry->delta_size &&
1689                     src->depth + 1 >= trg->depth) {
1690                         free(delta_buf);
1691                         return 0;
1692                 }
1693         }
1694
1695         /*
1696          * Handle memory allocation outside of the cache
1697          * accounting lock.  Compiler will optimize the strangeness
1698          * away when NO_PTHREADS is defined.
1699          */
1700         free(trg_entry->delta_data);
1701         cache_lock();
1702         if (trg_entry->delta_data) {
1703                 delta_cache_size -= trg_entry->delta_size;
1704                 trg_entry->delta_data = NULL;
1705         }
1706         if (delta_cacheable(src_size, trg_size, delta_size)) {
1707                 delta_cache_size += delta_size;
1708                 cache_unlock();
1709                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1710         } else {
1711                 cache_unlock();
1712                 free(delta_buf);
1713         }
1714
1715         trg_entry->delta = src_entry;
1716         trg_entry->delta_size = delta_size;
1717         trg->depth = src->depth + 1;
1718
1719         return 1;
1720 }
1721
1722 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1723 {
1724         struct object_entry *child = me->delta_child;
1725         unsigned int m = n;
1726         while (child) {
1727                 unsigned int c = check_delta_limit(child, n + 1);
1728                 if (m < c)
1729                         m = c;
1730                 child = child->delta_sibling;
1731         }
1732         return m;
1733 }
1734
1735 static unsigned long free_unpacked(struct unpacked *n)
1736 {
1737         unsigned long freed_mem = sizeof_delta_index(n->index);
1738         free_delta_index(n->index);
1739         n->index = NULL;
1740         if (n->data) {
1741                 freed_mem += n->entry->size;
1742                 free(n->data);
1743                 n->data = NULL;
1744         }
1745         n->entry = NULL;
1746         n->depth = 0;
1747         return freed_mem;
1748 }
1749
1750 static void find_deltas(struct object_entry **list, unsigned *list_size,
1751                         int window, int depth, unsigned *processed)
1752 {
1753         uint32_t i, idx = 0, count = 0;
1754         struct unpacked *array;
1755         unsigned long mem_usage = 0;
1756
1757         array = xcalloc(window, sizeof(struct unpacked));
1758
1759         for (;;) {
1760                 struct object_entry *entry;
1761                 struct unpacked *n = array + idx;
1762                 int j, max_depth, best_base = -1;
1763
1764                 progress_lock();
1765                 if (!*list_size) {
1766                         progress_unlock();
1767                         break;
1768                 }
1769                 entry = *list++;
1770                 (*list_size)--;
1771                 if (!entry->preferred_base) {
1772                         (*processed)++;
1773                         display_progress(progress_state, *processed);
1774                 }
1775                 progress_unlock();
1776
1777                 mem_usage -= free_unpacked(n);
1778                 n->entry = entry;
1779
1780                 while (window_memory_limit &&
1781                        mem_usage > window_memory_limit &&
1782                        count > 1) {
1783                         uint32_t tail = (idx + window - count) % window;
1784                         mem_usage -= free_unpacked(array + tail);
1785                         count--;
1786                 }
1787
1788                 /* We do not compute delta to *create* objects we are not
1789                  * going to pack.
1790                  */
1791                 if (entry->preferred_base)
1792                         goto next;
1793
1794                 /*
1795                  * If the current object is at pack edge, take the depth the
1796                  * objects that depend on the current object into account
1797                  * otherwise they would become too deep.
1798                  */
1799                 max_depth = depth;
1800                 if (entry->delta_child) {
1801                         max_depth -= check_delta_limit(entry, 0);
1802                         if (max_depth <= 0)
1803                                 goto next;
1804                 }
1805
1806                 j = window;
1807                 while (--j > 0) {
1808                         int ret;
1809                         uint32_t other_idx = idx + j;
1810                         struct unpacked *m;
1811                         if (other_idx >= window)
1812                                 other_idx -= window;
1813                         m = array + other_idx;
1814                         if (!m->entry)
1815                                 break;
1816                         ret = try_delta(n, m, max_depth, &mem_usage);
1817                         if (ret < 0)
1818                                 break;
1819                         else if (ret > 0)
1820                                 best_base = other_idx;
1821                 }
1822
1823                 /*
1824                  * If we decided to cache the delta data, then it is best
1825                  * to compress it right away.  First because we have to do
1826                  * it anyway, and doing it here while we're threaded will
1827                  * save a lot of time in the non threaded write phase,
1828                  * as well as allow for caching more deltas within
1829                  * the same cache size limit.
1830                  * ...
1831                  * But only if not writing to stdout, since in that case
1832                  * the network is most likely throttling writes anyway,
1833                  * and therefore it is best to go to the write phase ASAP
1834                  * instead, as we can afford spending more time compressing
1835                  * between writes at that moment.
1836                  */
1837                 if (entry->delta_data && !pack_to_stdout) {
1838                         entry->z_delta_size = do_compress(&entry->delta_data,
1839                                                           entry->delta_size);
1840                         cache_lock();
1841                         delta_cache_size -= entry->delta_size;
1842                         delta_cache_size += entry->z_delta_size;
1843                         cache_unlock();
1844                 }
1845
1846                 /* if we made n a delta, and if n is already at max
1847                  * depth, leaving it in the window is pointless.  we
1848                  * should evict it first.
1849                  */
1850                 if (entry->delta && max_depth <= n->depth)
1851                         continue;
1852
1853                 /*
1854                  * Move the best delta base up in the window, after the
1855                  * currently deltified object, to keep it longer.  It will
1856                  * be the first base object to be attempted next.
1857                  */
1858                 if (entry->delta) {
1859                         struct unpacked swap = array[best_base];
1860                         int dist = (window + idx - best_base) % window;
1861                         int dst = best_base;
1862                         while (dist--) {
1863                                 int src = (dst + 1) % window;
1864                                 array[dst] = array[src];
1865                                 dst = src;
1866                         }
1867                         array[dst] = swap;
1868                 }
1869
1870                 next:
1871                 idx++;
1872                 if (count + 1 < window)
1873                         count++;
1874                 if (idx >= window)
1875                         idx = 0;
1876         }
1877
1878         for (i = 0; i < window; ++i) {
1879                 free_delta_index(array[i].index);
1880                 free(array[i].data);
1881         }
1882         free(array);
1883 }
1884
1885 #ifndef NO_PTHREADS
1886
1887 static void try_to_free_from_threads(size_t size)
1888 {
1889         read_lock();
1890         release_pack_memory(size);
1891         read_unlock();
1892 }
1893
1894 static try_to_free_t old_try_to_free_routine;
1895
1896 /*
1897  * The main thread waits on the condition that (at least) one of the workers
1898  * has stopped working (which is indicated in the .working member of
1899  * struct thread_params).
1900  * When a work thread has completed its work, it sets .working to 0 and
1901  * signals the main thread and waits on the condition that .data_ready
1902  * becomes 1.
1903  */
1904
1905 struct thread_params {
1906         pthread_t thread;
1907         struct object_entry **list;
1908         unsigned list_size;
1909         unsigned remaining;
1910         int window;
1911         int depth;
1912         int working;
1913         int data_ready;
1914         pthread_mutex_t mutex;
1915         pthread_cond_t cond;
1916         unsigned *processed;
1917 };
1918
1919 static pthread_cond_t progress_cond;
1920
1921 /*
1922  * Mutex and conditional variable can't be statically-initialized on Windows.
1923  */
1924 static void init_threaded_search(void)
1925 {
1926         init_recursive_mutex(&read_mutex);
1927         pthread_mutex_init(&cache_mutex, NULL);
1928         pthread_mutex_init(&progress_mutex, NULL);
1929         pthread_cond_init(&progress_cond, NULL);
1930         old_try_to_free_routine = set_try_to_free_routine(try_to_free_from_threads);
1931 }
1932
1933 static void cleanup_threaded_search(void)
1934 {
1935         set_try_to_free_routine(old_try_to_free_routine);
1936         pthread_cond_destroy(&progress_cond);
1937         pthread_mutex_destroy(&read_mutex);
1938         pthread_mutex_destroy(&cache_mutex);
1939         pthread_mutex_destroy(&progress_mutex);
1940 }
1941
1942 static void *threaded_find_deltas(void *arg)
1943 {
1944         struct thread_params *me = arg;
1945
1946         while (me->remaining) {
1947                 find_deltas(me->list, &me->remaining,
1948                             me->window, me->depth, me->processed);
1949
1950                 progress_lock();
1951                 me->working = 0;
1952                 pthread_cond_signal(&progress_cond);
1953                 progress_unlock();
1954
1955                 /*
1956                  * We must not set ->data_ready before we wait on the
1957                  * condition because the main thread may have set it to 1
1958                  * before we get here. In order to be sure that new
1959                  * work is available if we see 1 in ->data_ready, it
1960                  * was initialized to 0 before this thread was spawned
1961                  * and we reset it to 0 right away.
1962                  */
1963                 pthread_mutex_lock(&me->mutex);
1964                 while (!me->data_ready)
1965                         pthread_cond_wait(&me->cond, &me->mutex);
1966                 me->data_ready = 0;
1967                 pthread_mutex_unlock(&me->mutex);
1968         }
1969         /* leave ->working 1 so that this doesn't get more work assigned */
1970         return NULL;
1971 }
1972
1973 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1974                            int window, int depth, unsigned *processed)
1975 {
1976         struct thread_params *p;
1977         int i, ret, active_threads = 0;
1978
1979         init_threaded_search();
1980
1981         if (delta_search_threads <= 1) {
1982                 find_deltas(list, &list_size, window, depth, processed);
1983                 cleanup_threaded_search();
1984                 return;
1985         }
1986         if (progress > pack_to_stdout)
1987                 fprintf(stderr, "Delta compression using up to %d threads.\n",
1988                                 delta_search_threads);
1989         p = xcalloc(delta_search_threads, sizeof(*p));
1990
1991         /* Partition the work amongst work threads. */
1992         for (i = 0; i < delta_search_threads; i++) {
1993                 unsigned sub_size = list_size / (delta_search_threads - i);
1994
1995                 /* don't use too small segments or no deltas will be found */
1996                 if (sub_size < 2*window && i+1 < delta_search_threads)
1997                         sub_size = 0;
1998
1999                 p[i].window = window;
2000                 p[i].depth = depth;
2001                 p[i].processed = processed;
2002                 p[i].working = 1;
2003                 p[i].data_ready = 0;
2004
2005                 /* try to split chunks on "path" boundaries */
2006                 while (sub_size && sub_size < list_size &&
2007                        list[sub_size]->hash &&
2008                        list[sub_size]->hash == list[sub_size-1]->hash)
2009                         sub_size++;
2010
2011                 p[i].list = list;
2012                 p[i].list_size = sub_size;
2013                 p[i].remaining = sub_size;
2014
2015                 list += sub_size;
2016                 list_size -= sub_size;
2017         }
2018
2019         /* Start work threads. */
2020         for (i = 0; i < delta_search_threads; i++) {
2021                 if (!p[i].list_size)
2022                         continue;
2023                 pthread_mutex_init(&p[i].mutex, NULL);
2024                 pthread_cond_init(&p[i].cond, NULL);
2025                 ret = pthread_create(&p[i].thread, NULL,
2026                                      threaded_find_deltas, &p[i]);
2027                 if (ret)
2028                         die("unable to create thread: %s", strerror(ret));
2029                 active_threads++;
2030         }
2031
2032         /*
2033          * Now let's wait for work completion.  Each time a thread is done
2034          * with its work, we steal half of the remaining work from the
2035          * thread with the largest number of unprocessed objects and give
2036          * it to that newly idle thread.  This ensure good load balancing
2037          * until the remaining object list segments are simply too short
2038          * to be worth splitting anymore.
2039          */
2040         while (active_threads) {
2041                 struct thread_params *target = NULL;
2042                 struct thread_params *victim = NULL;
2043                 unsigned sub_size = 0;
2044
2045                 progress_lock();
2046                 for (;;) {
2047                         for (i = 0; !target && i < delta_search_threads; i++)
2048                                 if (!p[i].working)
2049                                         target = &p[i];
2050                         if (target)
2051                                 break;
2052                         pthread_cond_wait(&progress_cond, &progress_mutex);
2053                 }
2054
2055                 for (i = 0; i < delta_search_threads; i++)
2056                         if (p[i].remaining > 2*window &&
2057                             (!victim || victim->remaining < p[i].remaining))
2058                                 victim = &p[i];
2059                 if (victim) {
2060                         sub_size = victim->remaining / 2;
2061                         list = victim->list + victim->list_size - sub_size;
2062                         while (sub_size && list[0]->hash &&
2063                                list[0]->hash == list[-1]->hash) {
2064                                 list++;
2065                                 sub_size--;
2066                         }
2067                         if (!sub_size) {
2068                                 /*
2069                                  * It is possible for some "paths" to have
2070                                  * so many objects that no hash boundary
2071                                  * might be found.  Let's just steal the
2072                                  * exact half in that case.
2073                                  */
2074                                 sub_size = victim->remaining / 2;
2075                                 list -= sub_size;
2076                         }
2077                         target->list = list;
2078                         victim->list_size -= sub_size;
2079                         victim->remaining -= sub_size;
2080                 }
2081                 target->list_size = sub_size;
2082                 target->remaining = sub_size;
2083                 target->working = 1;
2084                 progress_unlock();
2085
2086                 pthread_mutex_lock(&target->mutex);
2087                 target->data_ready = 1;
2088                 pthread_cond_signal(&target->cond);
2089                 pthread_mutex_unlock(&target->mutex);
2090
2091                 if (!sub_size) {
2092                         pthread_join(target->thread, NULL);
2093                         pthread_cond_destroy(&target->cond);
2094                         pthread_mutex_destroy(&target->mutex);
2095                         active_threads--;
2096                 }
2097         }
2098         cleanup_threaded_search();
2099         free(p);
2100 }
2101
2102 #else
2103 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
2104 #endif
2105
2106 static int add_ref_tag(const char *path, const struct object_id *oid, int flag, void *cb_data)
2107 {
2108         struct object_id peeled;
2109
2110         if (starts_with(path, "refs/tags/") && /* is a tag? */
2111             !peel_ref(path, peeled.hash)    && /* peelable? */
2112             packlist_find(&to_pack, peeled.hash, NULL))      /* object packed? */
2113                 add_object_entry(oid->hash, OBJ_TAG, NULL, 0);
2114         return 0;
2115 }
2116
2117 static void prepare_pack(int window, int depth)
2118 {
2119         struct object_entry **delta_list;
2120         uint32_t i, nr_deltas;
2121         unsigned n;
2122
2123         get_object_details();
2124
2125         /*
2126          * If we're locally repacking then we need to be doubly careful
2127          * from now on in order to make sure no stealth corruption gets
2128          * propagated to the new pack.  Clients receiving streamed packs
2129          * should validate everything they get anyway so no need to incur
2130          * the additional cost here in that case.
2131          */
2132         if (!pack_to_stdout)
2133                 do_check_packed_object_crc = 1;
2134
2135         if (!to_pack.nr_objects || !window || !depth)
2136                 return;
2137
2138         ALLOC_ARRAY(delta_list, to_pack.nr_objects);
2139         nr_deltas = n = 0;
2140
2141         for (i = 0; i < to_pack.nr_objects; i++) {
2142                 struct object_entry *entry = to_pack.objects + i;
2143
2144                 if (entry->delta)
2145                         /* This happens if we decided to reuse existing
2146                          * delta from a pack.  "reuse_delta &&" is implied.
2147                          */
2148                         continue;
2149
2150                 if (entry->size < 50)
2151                         continue;
2152
2153                 if (entry->no_try_delta)
2154                         continue;
2155
2156                 if (!entry->preferred_base) {
2157                         nr_deltas++;
2158                         if (entry->type < 0)
2159                                 die("unable to get type of object %s",
2160                                     sha1_to_hex(entry->idx.sha1));
2161                 } else {
2162                         if (entry->type < 0) {
2163                                 /*
2164                                  * This object is not found, but we
2165                                  * don't have to include it anyway.
2166                                  */
2167                                 continue;
2168                         }
2169                 }
2170
2171                 delta_list[n++] = entry;
2172         }
2173
2174         if (nr_deltas && n > 1) {
2175                 unsigned nr_done = 0;
2176                 if (progress)
2177                         progress_state = start_progress(_("Compressing objects"),
2178                                                         nr_deltas);
2179                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
2180                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
2181                 stop_progress(&progress_state);
2182                 if (nr_done != nr_deltas)
2183                         die("inconsistency with delta count");
2184         }
2185         free(delta_list);
2186 }
2187
2188 static int git_pack_config(const char *k, const char *v, void *cb)
2189 {
2190         if (!strcmp(k, "pack.window")) {
2191                 window = git_config_int(k, v);
2192                 return 0;
2193         }
2194         if (!strcmp(k, "pack.windowmemory")) {
2195                 window_memory_limit = git_config_ulong(k, v);
2196                 return 0;
2197         }
2198         if (!strcmp(k, "pack.depth")) {
2199                 depth = git_config_int(k, v);
2200                 return 0;
2201         }
2202         if (!strcmp(k, "pack.compression")) {
2203                 int level = git_config_int(k, v);
2204                 if (level == -1)
2205                         level = Z_DEFAULT_COMPRESSION;
2206                 else if (level < 0 || level > Z_BEST_COMPRESSION)
2207                         die("bad pack compression level %d", level);
2208                 pack_compression_level = level;
2209                 pack_compression_seen = 1;
2210                 return 0;
2211         }
2212         if (!strcmp(k, "pack.deltacachesize")) {
2213                 max_delta_cache_size = git_config_int(k, v);
2214                 return 0;
2215         }
2216         if (!strcmp(k, "pack.deltacachelimit")) {
2217                 cache_max_small_delta_size = git_config_int(k, v);
2218                 return 0;
2219         }
2220         if (!strcmp(k, "pack.writebitmaphashcache")) {
2221                 if (git_config_bool(k, v))
2222                         write_bitmap_options |= BITMAP_OPT_HASH_CACHE;
2223                 else
2224                         write_bitmap_options &= ~BITMAP_OPT_HASH_CACHE;
2225         }
2226         if (!strcmp(k, "pack.usebitmaps")) {
2227                 use_bitmap_index = git_config_bool(k, v);
2228                 return 0;
2229         }
2230         if (!strcmp(k, "pack.threads")) {
2231                 delta_search_threads = git_config_int(k, v);
2232                 if (delta_search_threads < 0)
2233                         die("invalid number of threads specified (%d)",
2234                             delta_search_threads);
2235 #ifdef NO_PTHREADS
2236                 if (delta_search_threads != 1)
2237                         warning("no threads support, ignoring %s", k);
2238 #endif
2239                 return 0;
2240         }
2241         if (!strcmp(k, "pack.indexversion")) {
2242                 pack_idx_opts.version = git_config_int(k, v);
2243                 if (pack_idx_opts.version > 2)
2244                         die("bad pack.indexversion=%"PRIu32,
2245                             pack_idx_opts.version);
2246                 return 0;
2247         }
2248         return git_default_config(k, v, cb);
2249 }
2250
2251 static void read_object_list_from_stdin(void)
2252 {
2253         char line[40 + 1 + PATH_MAX + 2];
2254         unsigned char sha1[20];
2255
2256         for (;;) {
2257                 if (!fgets(line, sizeof(line), stdin)) {
2258                         if (feof(stdin))
2259                                 break;
2260                         if (!ferror(stdin))
2261                                 die("fgets returned NULL, not EOF, not error!");
2262                         if (errno != EINTR)
2263                                 die_errno("fgets");
2264                         clearerr(stdin);
2265                         continue;
2266                 }
2267                 if (line[0] == '-') {
2268                         if (get_sha1_hex(line+1, sha1))
2269                                 die("expected edge sha1, got garbage:\n %s",
2270                                     line);
2271                         add_preferred_base(sha1);
2272                         continue;
2273                 }
2274                 if (get_sha1_hex(line, sha1))
2275                         die("expected sha1, got garbage:\n %s", line);
2276
2277                 add_preferred_base_object(line+41);
2278                 add_object_entry(sha1, 0, line+41, 0);
2279         }
2280 }
2281
2282 #define OBJECT_ADDED (1u<<20)
2283
2284 static void show_commit(struct commit *commit, void *data)
2285 {
2286         add_object_entry(commit->object.oid.hash, OBJ_COMMIT, NULL, 0);
2287         commit->object.flags |= OBJECT_ADDED;
2288
2289         if (write_bitmap_index)
2290                 index_commit_for_bitmap(commit);
2291 }
2292
2293 static void show_object(struct object *obj, const char *name, void *data)
2294 {
2295         add_preferred_base_object(name);
2296         add_object_entry(obj->oid.hash, obj->type, name, 0);
2297         obj->flags |= OBJECT_ADDED;
2298 }
2299
2300 static void show_edge(struct commit *commit)
2301 {
2302         add_preferred_base(commit->object.oid.hash);
2303 }
2304
2305 struct in_pack_object {
2306         off_t offset;
2307         struct object *object;
2308 };
2309
2310 struct in_pack {
2311         int alloc;
2312         int nr;
2313         struct in_pack_object *array;
2314 };
2315
2316 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
2317 {
2318         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->oid.hash, p);
2319         in_pack->array[in_pack->nr].object = object;
2320         in_pack->nr++;
2321 }
2322
2323 /*
2324  * Compare the objects in the offset order, in order to emulate the
2325  * "git rev-list --objects" output that produced the pack originally.
2326  */
2327 static int ofscmp(const void *a_, const void *b_)
2328 {
2329         struct in_pack_object *a = (struct in_pack_object *)a_;
2330         struct in_pack_object *b = (struct in_pack_object *)b_;
2331
2332         if (a->offset < b->offset)
2333                 return -1;
2334         else if (a->offset > b->offset)
2335                 return 1;
2336         else
2337                 return oidcmp(&a->object->oid, &b->object->oid);
2338 }
2339
2340 static void add_objects_in_unpacked_packs(struct rev_info *revs)
2341 {
2342         struct packed_git *p;
2343         struct in_pack in_pack;
2344         uint32_t i;
2345
2346         memset(&in_pack, 0, sizeof(in_pack));
2347
2348         for (p = packed_git; p; p = p->next) {
2349                 const unsigned char *sha1;
2350                 struct object *o;
2351
2352                 if (!p->pack_local || p->pack_keep)
2353                         continue;
2354                 if (open_pack_index(p))
2355                         die("cannot open pack index");
2356
2357                 ALLOC_GROW(in_pack.array,
2358                            in_pack.nr + p->num_objects,
2359                            in_pack.alloc);
2360
2361                 for (i = 0; i < p->num_objects; i++) {
2362                         sha1 = nth_packed_object_sha1(p, i);
2363                         o = lookup_unknown_object(sha1);
2364                         if (!(o->flags & OBJECT_ADDED))
2365                                 mark_in_pack_object(o, p, &in_pack);
2366                         o->flags |= OBJECT_ADDED;
2367                 }
2368         }
2369
2370         if (in_pack.nr) {
2371                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
2372                       ofscmp);
2373                 for (i = 0; i < in_pack.nr; i++) {
2374                         struct object *o = in_pack.array[i].object;
2375                         add_object_entry(o->oid.hash, o->type, "", 0);
2376                 }
2377         }
2378         free(in_pack.array);
2379 }
2380
2381 static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2382 {
2383         static struct packed_git *last_found = (void *)1;
2384         struct packed_git *p;
2385
2386         p = (last_found != (void *)1) ? last_found : packed_git;
2387
2388         while (p) {
2389                 if ((!p->pack_local || p->pack_keep) &&
2390                         find_pack_entry_one(sha1, p)) {
2391                         last_found = p;
2392                         return 1;
2393                 }
2394                 if (p == last_found)
2395                         p = packed_git;
2396                 else
2397                         p = p->next;
2398                 if (p == last_found)
2399                         p = p->next;
2400         }
2401         return 0;
2402 }
2403
2404 /*
2405  * Store a list of sha1s that are should not be discarded
2406  * because they are either written too recently, or are
2407  * reachable from another object that was.
2408  *
2409  * This is filled by get_object_list.
2410  */
2411 static struct sha1_array recent_objects;
2412
2413 static int loosened_object_can_be_discarded(const unsigned char *sha1,
2414                                             unsigned long mtime)
2415 {
2416         if (!unpack_unreachable_expiration)
2417                 return 0;
2418         if (mtime > unpack_unreachable_expiration)
2419                 return 0;
2420         if (sha1_array_lookup(&recent_objects, sha1) >= 0)
2421                 return 0;
2422         return 1;
2423 }
2424
2425 static void loosen_unused_packed_objects(struct rev_info *revs)
2426 {
2427         struct packed_git *p;
2428         uint32_t i;
2429         const unsigned char *sha1;
2430
2431         for (p = packed_git; p; p = p->next) {
2432                 if (!p->pack_local || p->pack_keep)
2433                         continue;
2434
2435                 if (open_pack_index(p))
2436                         die("cannot open pack index");
2437
2438                 for (i = 0; i < p->num_objects; i++) {
2439                         sha1 = nth_packed_object_sha1(p, i);
2440                         if (!packlist_find(&to_pack, sha1, NULL) &&
2441                             !has_sha1_pack_kept_or_nonlocal(sha1) &&
2442                             !loosened_object_can_be_discarded(sha1, p->mtime))
2443                                 if (force_object_loose(sha1, p->mtime))
2444                                         die("unable to force loose object");
2445                 }
2446         }
2447 }
2448
2449 /*
2450  * This tracks any options which a reader of the pack might
2451  * not understand, and which would therefore prevent blind reuse
2452  * of what we have on disk.
2453  */
2454 static int pack_options_allow_reuse(void)
2455 {
2456         return allow_ofs_delta;
2457 }
2458
2459 static int get_object_list_from_bitmap(struct rev_info *revs)
2460 {
2461         if (prepare_bitmap_walk(revs) < 0)
2462                 return -1;
2463
2464         if (pack_options_allow_reuse() &&
2465             !reuse_partial_packfile_from_bitmap(
2466                         &reuse_packfile,
2467                         &reuse_packfile_objects,
2468                         &reuse_packfile_offset)) {
2469                 assert(reuse_packfile_objects);
2470                 nr_result += reuse_packfile_objects;
2471                 display_progress(progress_state, nr_result);
2472         }
2473
2474         traverse_bitmap_commit_list(&add_object_entry_from_bitmap);
2475         return 0;
2476 }
2477
2478 static void record_recent_object(struct object *obj,
2479                                  const char *name,
2480                                  void *data)
2481 {
2482         sha1_array_append(&recent_objects, obj->oid.hash);
2483 }
2484
2485 static void record_recent_commit(struct commit *commit, void *data)
2486 {
2487         sha1_array_append(&recent_objects, commit->object.oid.hash);
2488 }
2489
2490 static void get_object_list(int ac, const char **av)
2491 {
2492         struct rev_info revs;
2493         char line[1000];
2494         int flags = 0;
2495
2496         init_revisions(&revs, NULL);
2497         save_commit_buffer = 0;
2498         setup_revisions(ac, av, &revs, NULL);
2499
2500         /* make sure shallows are read */
2501         is_repository_shallow();
2502
2503         while (fgets(line, sizeof(line), stdin) != NULL) {
2504                 int len = strlen(line);
2505                 if (len && line[len - 1] == '\n')
2506                         line[--len] = 0;
2507                 if (!len)
2508                         break;
2509                 if (*line == '-') {
2510                         if (!strcmp(line, "--not")) {
2511                                 flags ^= UNINTERESTING;
2512                                 write_bitmap_index = 0;
2513                                 continue;
2514                         }
2515                         if (starts_with(line, "--shallow ")) {
2516                                 unsigned char sha1[20];
2517                                 if (get_sha1_hex(line + 10, sha1))
2518                                         die("not an SHA-1 '%s'", line + 10);
2519                                 register_shallow(sha1);
2520                                 use_bitmap_index = 0;
2521                                 continue;
2522                         }
2523                         die("not a rev '%s'", line);
2524                 }
2525                 if (handle_revision_arg(line, &revs, flags, REVARG_CANNOT_BE_FILENAME))
2526                         die("bad revision '%s'", line);
2527         }
2528
2529         if (use_bitmap_index && !get_object_list_from_bitmap(&revs))
2530                 return;
2531
2532         if (prepare_revision_walk(&revs))
2533                 die("revision walk setup failed");
2534         mark_edges_uninteresting(&revs, show_edge);
2535         traverse_commit_list(&revs, show_commit, show_object, NULL);
2536
2537         if (unpack_unreachable_expiration) {
2538                 revs.ignore_missing_links = 1;
2539                 if (add_unseen_recent_objects_to_traversal(&revs,
2540                                 unpack_unreachable_expiration))
2541                         die("unable to add recent objects");
2542                 if (prepare_revision_walk(&revs))
2543                         die("revision walk setup failed");
2544                 traverse_commit_list(&revs, record_recent_commit,
2545                                      record_recent_object, NULL);
2546         }
2547
2548         if (keep_unreachable)
2549                 add_objects_in_unpacked_packs(&revs);
2550         if (unpack_unreachable)
2551                 loosen_unused_packed_objects(&revs);
2552
2553         sha1_array_clear(&recent_objects);
2554 }
2555
2556 static int option_parse_index_version(const struct option *opt,
2557                                       const char *arg, int unset)
2558 {
2559         char *c;
2560         const char *val = arg;
2561         pack_idx_opts.version = strtoul(val, &c, 10);
2562         if (pack_idx_opts.version > 2)
2563                 die(_("unsupported index version %s"), val);
2564         if (*c == ',' && c[1])
2565                 pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
2566         if (*c || pack_idx_opts.off32_limit & 0x80000000)
2567                 die(_("bad index version '%s'"), val);
2568         return 0;
2569 }
2570
2571 static int option_parse_unpack_unreachable(const struct option *opt,
2572                                            const char *arg, int unset)
2573 {
2574         if (unset) {
2575                 unpack_unreachable = 0;
2576                 unpack_unreachable_expiration = 0;
2577         }
2578         else {
2579                 unpack_unreachable = 1;
2580                 if (arg)
2581                         unpack_unreachable_expiration = approxidate(arg);
2582         }
2583         return 0;
2584 }
2585
2586 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2587 {
2588         int use_internal_rev_list = 0;
2589         int thin = 0;
2590         int shallow = 0;
2591         int all_progress_implied = 0;
2592         struct argv_array rp = ARGV_ARRAY_INIT;
2593         int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
2594         int rev_list_index = 0;
2595         struct option pack_objects_options[] = {
2596                 OPT_SET_INT('q', "quiet", &progress,
2597                             N_("do not show progress meter"), 0),
2598                 OPT_SET_INT(0, "progress", &progress,
2599                             N_("show progress meter"), 1),
2600                 OPT_SET_INT(0, "all-progress", &progress,
2601                             N_("show progress meter during object writing phase"), 2),
2602                 OPT_BOOL(0, "all-progress-implied",
2603                          &all_progress_implied,
2604                          N_("similar to --all-progress when progress meter is shown")),
2605                 { OPTION_CALLBACK, 0, "index-version", NULL, N_("version[,offset]"),
2606                   N_("write the pack index file in the specified idx format version"),
2607                   0, option_parse_index_version },
2608                 OPT_MAGNITUDE(0, "max-pack-size", &pack_size_limit,
2609                               N_("maximum size of each output pack file")),
2610                 OPT_BOOL(0, "local", &local,
2611                          N_("ignore borrowed objects from alternate object store")),
2612                 OPT_BOOL(0, "incremental", &incremental,
2613                          N_("ignore packed objects")),
2614                 OPT_INTEGER(0, "window", &window,
2615                             N_("limit pack window by objects")),
2616                 OPT_MAGNITUDE(0, "window-memory", &window_memory_limit,
2617                               N_("limit pack window by memory in addition to object limit")),
2618                 OPT_INTEGER(0, "depth", &depth,
2619                             N_("maximum length of delta chain allowed in the resulting pack")),
2620                 OPT_BOOL(0, "reuse-delta", &reuse_delta,
2621                          N_("reuse existing deltas")),
2622                 OPT_BOOL(0, "reuse-object", &reuse_object,
2623                          N_("reuse existing objects")),
2624                 OPT_BOOL(0, "delta-base-offset", &allow_ofs_delta,
2625                          N_("use OFS_DELTA objects")),
2626                 OPT_INTEGER(0, "threads", &delta_search_threads,
2627                             N_("use threads when searching for best delta matches")),
2628                 OPT_BOOL(0, "non-empty", &non_empty,
2629                          N_("do not create an empty pack output")),
2630                 OPT_BOOL(0, "revs", &use_internal_rev_list,
2631                          N_("read revision arguments from standard input")),
2632                 { OPTION_SET_INT, 0, "unpacked", &rev_list_unpacked, NULL,
2633                   N_("limit the objects to those that are not yet packed"),
2634                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2635                 { OPTION_SET_INT, 0, "all", &rev_list_all, NULL,
2636                   N_("include objects reachable from any reference"),
2637                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2638                 { OPTION_SET_INT, 0, "reflog", &rev_list_reflog, NULL,
2639                   N_("include objects referred by reflog entries"),
2640                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2641                 { OPTION_SET_INT, 0, "indexed-objects", &rev_list_index, NULL,
2642                   N_("include objects referred to by the index"),
2643                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2644                 OPT_BOOL(0, "stdout", &pack_to_stdout,
2645                          N_("output pack to stdout")),
2646                 OPT_BOOL(0, "include-tag", &include_tag,
2647                          N_("include tag objects that refer to objects to be packed")),
2648                 OPT_BOOL(0, "keep-unreachable", &keep_unreachable,
2649                          N_("keep unreachable objects")),
2650                 { OPTION_CALLBACK, 0, "unpack-unreachable", NULL, N_("time"),
2651                   N_("unpack unreachable objects newer than <time>"),
2652                   PARSE_OPT_OPTARG, option_parse_unpack_unreachable },
2653                 OPT_BOOL(0, "thin", &thin,
2654                          N_("create thin packs")),
2655                 OPT_BOOL(0, "shallow", &shallow,
2656                          N_("create packs suitable for shallow fetches")),
2657                 OPT_BOOL(0, "honor-pack-keep", &ignore_packed_keep,
2658                          N_("ignore packs that have companion .keep file")),
2659                 OPT_INTEGER(0, "compression", &pack_compression_level,
2660                             N_("pack compression level")),
2661                 OPT_SET_INT(0, "keep-true-parents", &grafts_replace_parents,
2662                             N_("do not hide commits by grafts"), 0),
2663                 OPT_BOOL(0, "use-bitmap-index", &use_bitmap_index,
2664                          N_("use a bitmap index if available to speed up counting objects")),
2665                 OPT_BOOL(0, "write-bitmap-index", &write_bitmap_index,
2666                          N_("write a bitmap index together with the pack index")),
2667                 OPT_END(),
2668         };
2669
2670         check_replace_refs = 0;
2671
2672         reset_pack_idx_option(&pack_idx_opts);
2673         git_config(git_pack_config, NULL);
2674         if (!pack_compression_seen && core_compression_seen)
2675                 pack_compression_level = core_compression_level;
2676
2677         progress = isatty(2);
2678         argc = parse_options(argc, argv, prefix, pack_objects_options,
2679                              pack_usage, 0);
2680
2681         if (argc) {
2682                 base_name = argv[0];
2683                 argc--;
2684         }
2685         if (pack_to_stdout != !base_name || argc)
2686                 usage_with_options(pack_usage, pack_objects_options);
2687
2688         argv_array_push(&rp, "pack-objects");
2689         if (thin) {
2690                 use_internal_rev_list = 1;
2691                 argv_array_push(&rp, shallow
2692                                 ? "--objects-edge-aggressive"
2693                                 : "--objects-edge");
2694         } else
2695                 argv_array_push(&rp, "--objects");
2696
2697         if (rev_list_all) {
2698                 use_internal_rev_list = 1;
2699                 argv_array_push(&rp, "--all");
2700         }
2701         if (rev_list_reflog) {
2702                 use_internal_rev_list = 1;
2703                 argv_array_push(&rp, "--reflog");
2704         }
2705         if (rev_list_index) {
2706                 use_internal_rev_list = 1;
2707                 argv_array_push(&rp, "--indexed-objects");
2708         }
2709         if (rev_list_unpacked) {
2710                 use_internal_rev_list = 1;
2711                 argv_array_push(&rp, "--unpacked");
2712         }
2713
2714         if (!reuse_object)
2715                 reuse_delta = 0;
2716         if (pack_compression_level == -1)
2717                 pack_compression_level = Z_DEFAULT_COMPRESSION;
2718         else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
2719                 die("bad pack compression level %d", pack_compression_level);
2720
2721         if (!delta_search_threads)      /* --threads=0 means autodetect */
2722                 delta_search_threads = online_cpus();
2723
2724 #ifdef NO_PTHREADS
2725         if (delta_search_threads != 1)
2726                 warning("no threads support, ignoring --threads");
2727 #endif
2728         if (!pack_to_stdout && !pack_size_limit)
2729                 pack_size_limit = pack_size_limit_cfg;
2730         if (pack_to_stdout && pack_size_limit)
2731                 die("--max-pack-size cannot be used to build a pack for transfer.");
2732         if (pack_size_limit && pack_size_limit < 1024*1024) {
2733                 warning("minimum pack size limit is 1 MiB");
2734                 pack_size_limit = 1024*1024;
2735         }
2736
2737         if (!pack_to_stdout && thin)
2738                 die("--thin cannot be used to build an indexable pack.");
2739
2740         if (keep_unreachable && unpack_unreachable)
2741                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2742         if (!rev_list_all || !rev_list_reflog || !rev_list_index)
2743                 unpack_unreachable_expiration = 0;
2744
2745         if (!use_internal_rev_list || !pack_to_stdout || is_repository_shallow())
2746                 use_bitmap_index = 0;
2747
2748         if (pack_to_stdout || !rev_list_all)
2749                 write_bitmap_index = 0;
2750
2751         if (progress && all_progress_implied)
2752                 progress = 2;
2753
2754         prepare_packed_git();
2755
2756         if (progress)
2757                 progress_state = start_progress(_("Counting objects"), 0);
2758         if (!use_internal_rev_list)
2759                 read_object_list_from_stdin();
2760         else {
2761                 get_object_list(rp.argc, rp.argv);
2762                 argv_array_clear(&rp);
2763         }
2764         cleanup_preferred_base();
2765         if (include_tag && nr_result)
2766                 for_each_ref(add_ref_tag, NULL);
2767         stop_progress(&progress_state);
2768
2769         if (non_empty && !nr_result)
2770                 return 0;
2771         if (nr_result)
2772                 prepare_pack(window, depth);
2773         write_pack_file();
2774         if (progress)
2775                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2776                         " reused %"PRIu32" (delta %"PRIu32")\n",
2777                         written, written_delta, reused, reused_delta);
2778         return 0;
2779 }