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         memset(&stream, 0, sizeof(stream));
 129         git_deflate_init(&stream, pack_compression_level);
 130         maxsize = git_deflate_bound(&stream, size);
 131
 132         in = *pptr;
 133         out = xmalloc(maxsize);
 134         *pptr = out;
 135
 136         stream.next_in = in;
 137         stream.avail_in = size;
 138         stream.next_out = out;
 139         stream.avail_out = maxsize;
 140         while (git_deflate(&stream, Z_FINISH) == Z_OK)
 141                 ; /* nothing */
 142         git_deflate_end(&stream);
 143
 144         free(in);
 145         return stream.total_out;
 146 }
 147
 148 static unsigned long write_large_blob_data(struct git_istream *st, struct sha1file *f,
 149                                            const unsigned char *sha1)
 150 {
 151         git_zstream stream;
 152         unsigned char ibuf[1024 * 16];
 153         unsigned char obuf[1024 * 16];
 154         unsigned long olen = 0;
 155
 156         memset(&stream, 0, sizeof(stream));
 157         git_deflate_init(&stream, pack_compression_level);
 158
 159         for (;;) {
 160                 ssize_t readlen;
 161                 int zret = Z_OK;
 162                 readlen = read_istream(st, ibuf, sizeof(ibuf));
 163                 if (readlen == -1)
 164                         die(_("unable to read %s"), sha1_to_hex(sha1));
 165
 166                 stream.next_in = ibuf;
 167                 stream.avail_in = readlen;
 168                 while ((stream.avail_in || readlen == 0) &&
 169                        (zret == Z_OK || zret == Z_BUF_ERROR)) {
 170                         stream.next_out = obuf;
 171                         stream.avail_out = sizeof(obuf);
 172                         zret = git_deflate(&stream, readlen ? 0 : Z_FINISH);
 173                         sha1write(f, obuf, stream.next_out - obuf);
 174                         olen += stream.next_out - obuf;
 175                 }
 176                 if (stream.avail_in)
 177                         die(_("deflate error (%d)"), zret);
 178                 if (readlen == 0) {
 179                         if (zret != Z_STREAM_END)
 180                                 die(_("deflate error (%d)"), zret);
 181                         break;
 182                 }
 183         }
 184         git_deflate_end(&stream);
 185         return olen;
 186 }
 187
 188 /*
 189  * we are going to reuse the existing object data as is.  make
 190  * sure it is not corrupt.
 191  */
 192 static int check_pack_inflate(struct packed_git *p,
 193                 struct pack_window **w_curs,
 194                 off_t offset,
 195                 off_t len,
 196                 unsigned long expect)
 197 {
 198         git_zstream stream;
 199         unsigned char fakebuf[4096], *in;
 200         int st;
 201
 202         memset(&stream, 0, sizeof(stream));
 203         git_inflate_init(&stream);
 204         do {
 205                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 206                 stream.next_in = in;
 207                 stream.next_out = fakebuf;
 208                 stream.avail_out = sizeof(fakebuf);
 209                 st = git_inflate(&stream, Z_FINISH);
 210                 offset += stream.next_in - in;
 211         } while (st == Z_OK || st == Z_BUF_ERROR);
 212         git_inflate_end(&stream);
 213         return (st == Z_STREAM_END &&
 214                 stream.total_out == expect &&
 215                 stream.total_in == len) ? 0 : -1;
 216 }
 217
 218 static void copy_pack_data(struct sha1file *f,
 219                 struct packed_git *p,
 220                 struct pack_window **w_curs,
 221                 off_t offset,
 222                 off_t len)
 223 {
 224         unsigned char *in;
 225         unsigned long avail;
 226
 227         while (len) {
 228                 in = use_pack(p, w_curs, offset, &avail);
 229                 if (avail > len)
 230                         avail = (unsigned long)len;
 231                 sha1write(f, in, avail);
 232                 offset += avail;
 233                 len -= avail;
 234         }
 235 }
 236
 237 /* Return 0 if we will bust the pack-size limit */
 238 static unsigned long write_no_reuse_object(struct sha1file *f, struct object_entry *entry,
 239                                            unsigned long limit, int usable_delta)
 240 {
 241         unsigned long size, datalen;
 242         unsigned char header[10], dheader[10];
 243         unsigned hdrlen;
 244         enum object_type type;
 245         void *buf;
 246         struct git_istream *st = NULL;
 247
 248         if (!usable_delta) {
 249                 if (entry->type == OBJ_BLOB &&
 250                     entry->size > big_file_threshold &&
 251                     (st = open_istream(entry->idx.sha1, &type, &size, NULL)) != NULL)
 252                         buf = NULL;
 253                 else {
 254                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 255                         if (!buf)
 256                                 die(_("unable to read %s"), sha1_to_hex(entry->idx.sha1));
 257                 }
 258                 /*
 259                  * make sure no cached delta data remains from a
 260                  * previous attempt before a pack split occurred.
 261                  */
 262                 free(entry->delta_data);
 263                 entry->delta_data = NULL;
 264                 entry->z_delta_size = 0;
 265         } else if (entry->delta_data) {
 266                 size = entry->delta_size;
 267                 buf = entry->delta_data;
 268                 entry->delta_data = NULL;
 269                 type = (allow_ofs_delta && entry->delta->idx.offset) ?
 270                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 271         } else {
 272                 buf = get_delta(entry);
 273                 size = entry->delta_size;
 274                 type = (allow_ofs_delta && entry->delta->idx.offset) ?
 275                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 276         }
 277
 278         if (st) /* large blob case, just assume we don't compress well */
 279                 datalen = size;
 280         else if (entry->z_delta_size)
 281                 datalen = entry->z_delta_size;
 282         else
 283                 datalen = do_compress(&buf, size);
 284
 285         /*
 286          * The object header is a byte of 'type' followed by zero or
 287          * more bytes of length.
 288          */
 289         hdrlen = encode_in_pack_object_header(type, size, header);
 290
 291         if (type == OBJ_OFS_DELTA) {
 292                 /*
 293                  * Deltas with relative base contain an additional
 294                  * encoding of the relative offset for the delta
 295                  * base from this object's position in the pack.
 296                  */
 297                 off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 298                 unsigned pos = sizeof(dheader) - 1;
 299                 dheader[pos] = ofs & 127;
 300                 while (ofs >>= 7)
 301                         dheader[--pos] = 128 | (--ofs & 127);
 302                 if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 303                         if (st)
 304                                 close_istream(st);
 305                         free(buf);
 306                         return 0;
 307                 }
 308                 sha1write(f, header, hdrlen);
 309                 sha1write(f, dheader + pos, sizeof(dheader) - pos);
 310                 hdrlen += sizeof(dheader) - pos;
 311         } else if (type == OBJ_REF_DELTA) {
 312                 /*
 313                  * Deltas with a base reference contain
 314                  * an additional 20 bytes for the base sha1.
 315                  */
 316                 if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 317                         if (st)
 318                                 close_istream(st);
 319                         free(buf);
 320                         return 0;
 321                 }
 322                 sha1write(f, header, hdrlen);
 323                 sha1write(f, entry->delta->idx.sha1, 20);
 324                 hdrlen += 20;
 325         } else {
 326                 if (limit && hdrlen + datalen + 20 >= limit) {
 327                         if (st)
 328                                 close_istream(st);
 329                         free(buf);
 330                         return 0;
 331                 }
 332                 sha1write(f, header, hdrlen);
 333         }
 334         if (st) {
 335                 datalen = write_large_blob_data(st, f, entry->idx.sha1);
 336                 close_istream(st);
 337         } else {
 338                 sha1write(f, buf, datalen);
 339                 free(buf);
 340         }
 341
 342         return hdrlen + datalen;
 343 }
 344
 345 /* Return 0 if we will bust the pack-size limit */
 346 static unsigned long write_reuse_object(struct sha1file *f, struct object_entry *entry,
 347                                         unsigned long limit, int usable_delta)
 348 {
 349         struct packed_git *p = entry->in_pack;
 350         struct pack_window *w_curs = NULL;
 351         struct revindex_entry *revidx;
 352         off_t offset;
 353         enum object_type type = entry->type;
 354         unsigned long datalen;
 355         unsigned char header[10], dheader[10];
 356         unsigned hdrlen;
 357
 358         if (entry->delta)
 359                 type = (allow_ofs_delta && entry->delta->idx.offset) ?
 360                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
 361         hdrlen = encode_in_pack_object_header(type, entry->size, header);
 362
 363         offset = entry->in_pack_offset;
 364         revidx = find_pack_revindex(p, offset);
 365         datalen = revidx[1].offset - offset;
 366         if (!pack_to_stdout && p->index_version > 1 &&
 367             check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 368                 error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 369                 unuse_pack(&w_curs);
 370                 return write_no_reuse_object(f, entry, limit, usable_delta);
 371         }
 372
 373         offset += entry->in_pack_header_size;
 374         datalen -= entry->in_pack_header_size;
 375
 376         if (!pack_to_stdout && p->index_version == 1 &&
 377             check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
 378                 error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 379                 unuse_pack(&w_curs);
 380                 return write_no_reuse_object(f, entry, limit, usable_delta);
 381         }
 382
 383         if (type == OBJ_OFS_DELTA) {
 384                 off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 385                 unsigned pos = sizeof(dheader) - 1;
 386                 dheader[pos] = ofs & 127;
 387                 while (ofs >>= 7)
 388                         dheader[--pos] = 128 | (--ofs & 127);
 389                 if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 390                         unuse_pack(&w_curs);
 391                         return 0;
 392                 }
 393                 sha1write(f, header, hdrlen);
 394                 sha1write(f, dheader + pos, sizeof(dheader) - pos);
 395                 hdrlen += sizeof(dheader) - pos;
 396                 reused_delta++;
 397         } else if (type == OBJ_REF_DELTA) {
 398                 if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 399                         unuse_pack(&w_curs);
 400                         return 0;
 401                 }
 402                 sha1write(f, header, hdrlen);
 403                 sha1write(f, entry->delta->idx.sha1, 20);
 404                 hdrlen += 20;
 405                 reused_delta++;
 406         } else {
 407                 if (limit && hdrlen + datalen + 20 >= limit) {
 408                         unuse_pack(&w_curs);
 409                         return 0;
 410                 }
 411                 sha1write(f, header, hdrlen);
 412         }
 413         copy_pack_data(f, p, &w_curs, offset, datalen);
 414         unuse_pack(&w_curs);
 415         reused++;
 416         return hdrlen + datalen;
 417 }
 418
 419 /* Return 0 if we will bust the pack-size limit */
 420 static unsigned long write_object(struct sha1file *f,
 421                                   struct object_entry *entry,
 422                                   off_t write_offset)
 423 {
 424         unsigned long limit, len;
 425         int usable_delta, to_reuse;
 426
 427         if (!pack_to_stdout)
 428                 crc32_begin(f);
 429
 430         /* apply size limit if limited packsize and not first object */
 431         if (!pack_size_limit || !nr_written)
 432                 limit = 0;
 433         else if (pack_size_limit <= write_offset)
 434                 /*
 435                  * the earlier object did not fit the limit; avoid
 436                  * mistaking this with unlimited (i.e. limit = 0).
 437                  */
 438                 limit = 1;
 439         else
 440                 limit = pack_size_limit - write_offset;
 441
 442         if (!entry->delta)
 443                 usable_delta = 0;       /* no delta */
 444         else if (!pack_size_limit)
 445                usable_delta = 1;        /* unlimited packfile */
 446         else if (entry->delta->idx.offset == (off_t)-1)
 447                 usable_delta = 0;       /* base was written to another pack */
 448         else if (entry->delta->idx.offset)
 449                 usable_delta = 1;       /* base already exists in this pack */
 450         else
 451                 usable_delta = 0;       /* base could end up in another pack */
 452
 453         if (!reuse_object)
 454                 to_reuse = 0;   /* explicit */
 455         else if (!entry->in_pack)
 456                 to_reuse = 0;   /* can't reuse what we don't have */
 457         else if (entry->type == OBJ_REF_DELTA || entry->type == OBJ_OFS_DELTA)
 458                                 /* check_object() decided it for us ... */
 459                 to_reuse = usable_delta;
 460                                 /* ... but pack split may override that */
 461         else if (entry->type != entry->in_pack_type)
 462                 to_reuse = 0;   /* pack has delta which is unusable */
 463         else if (entry->delta)
 464                 to_reuse = 0;   /* we want to pack afresh */
 465         else
 466                 to_reuse = 1;   /* we have it in-pack undeltified,
 467                                  * and we do not need to deltify it.
 468                                  */
 469
 470         if (!to_reuse)
 471                 len = write_no_reuse_object(f, entry, limit, usable_delta);
 472         else
 473                 len = write_reuse_object(f, entry, limit, usable_delta);
 474         if (!len)
 475                 return 0;
 476
 477         if (usable_delta)
 478                 written_delta++;
 479         written++;
 480         if (!pack_to_stdout)
 481                 entry->idx.crc32 = crc32_end(f);
 482         return len;
 483 }
 484
 485 enum write_one_status {
 486         WRITE_ONE_SKIP = -1, /* already written */
 487         WRITE_ONE_BREAK = 0, /* writing this will bust the limit; not written */
 488         WRITE_ONE_WRITTEN = 1, /* normal */
 489         WRITE_ONE_RECURSIVE = 2 /* already scheduled to be written */
 490 };
 491
 492 static enum write_one_status write_one(struct sha1file *f,
 493                                        struct object_entry *e,
 494                                        off_t *offset)
 495 {
 496         unsigned long size;
 497         int recursing;
 498
 499         /*
 500          * we set offset to 1 (which is an impossible value) to mark
 501          * the fact that this object is involved in "write its base
 502          * first before writing a deltified object" recursion.
 503          */
 504         recursing = (e->idx.offset == 1);
 505         if (recursing) {
 506                 warning("recursive delta detected for object %s",
 507                         sha1_to_hex(e->idx.sha1));
 508                 return WRITE_ONE_RECURSIVE;
 509         } else if (e->idx.offset || e->preferred_base) {
 510                 /* offset is non zero if object is written already. */
 511                 return WRITE_ONE_SKIP;
 512         }
 513
 514         /* if we are deltified, write out base object first. */
 515         if (e->delta) {
 516                 e->idx.offset = 1; /* now recurse */
 517                 switch (write_one(f, e->delta, offset)) {
 518                 case WRITE_ONE_RECURSIVE:
 519                         /* we cannot depend on this one */
 520                         e->delta = NULL;
 521                         break;
 522                 default:
 523                         break;
 524                 case WRITE_ONE_BREAK:
 525                         e->idx.offset = recursing;
 526                         return WRITE_ONE_BREAK;
 527                 }
 528         }
 529
 530         e->idx.offset = *offset;
 531         size = write_object(f, e, *offset);
 532         if (!size) {
 533                 e->idx.offset = recursing;
 534                 return WRITE_ONE_BREAK;
 535         }
 536         written_list[nr_written++] = &e->idx;
 537
 538         /* make sure off_t is sufficiently large not to wrap */
 539         if (signed_add_overflows(*offset, size))
 540                 die("pack too large for current definition of off_t");
 541         *offset += size;
 542         return WRITE_ONE_WRITTEN;
 543 }
 544
 545 static int mark_tagged(const char *path, const unsigned char *sha1, int flag,
 546                        void *cb_data)
 547 {
 548         unsigned char peeled[20];
 549         struct object_entry *entry = packlist_find(&to_pack, sha1, NULL);
 550
 551         if (entry)
 552                 entry->tagged = 1;
 553         if (!peel_ref(path, peeled)) {
 554                 entry = packlist_find(&to_pack, peeled, NULL);
 555                 if (entry)
 556                         entry->tagged = 1;
 557         }
 558         return 0;
 559 }
 560
 561 static inline void add_to_write_order(struct object_entry **wo,
 562                                unsigned int *endp,
 563                                struct object_entry *e)
 564 {
 565         if (e->filled)
 566                 return;
 567         wo[(*endp)++] = e;
 568         e->filled = 1;
 569 }
 570
 571 static void add_descendants_to_write_order(struct object_entry **wo,
 572                                            unsigned int *endp,
 573                                            struct object_entry *e)
 574 {
 575         int add_to_order = 1;
 576         while (e) {
 577                 if (add_to_order) {
 578                         struct object_entry *s;
 579                         /* add this node... */
 580                         add_to_write_order(wo, endp, e);
 581                         /* all its siblings... */
 582                         for (s = e->delta_sibling; s; s = s->delta_sibling) {
 583                                 add_to_write_order(wo, endp, s);
 584                         }
 585                 }
 586                 /* drop down a level to add left subtree nodes if possible */
 587                 if (e->delta_child) {
 588                         add_to_order = 1;
 589                         e = e->delta_child;
 590                 } else {
 591                         add_to_order = 0;
 592                         /* our sibling might have some children, it is next */
 593                         if (e->delta_sibling) {
 594                                 e = e->delta_sibling;
 595                                 continue;
 596                         }
 597                         /* go back to our parent node */
 598                         e = e->delta;
 599                         while (e && !e->delta_sibling) {
 600                                 /* we're on the right side of a subtree, keep
 601                                  * going up until we can go right again */
 602                                 e = e->delta;
 603                         }
 604                         if (!e) {
 605                                 /* done- we hit our original root node */
 606                                 return;
 607                         }
 608                         /* pass it off to sibling at this level */
 609                         e = e->delta_sibling;
 610                 }
 611         };
 612 }
 613
 614 static void add_family_to_write_order(struct object_entry **wo,
 615                                       unsigned int *endp,
 616                                       struct object_entry *e)
 617 {
 618         struct object_entry *root;
 619
 620         for (root = e; root->delta; root = root->delta)
 621                 ; /* nothing */
 622         add_descendants_to_write_order(wo, endp, root);
 623 }
 624
 625 static struct object_entry **compute_write_order(void)
 626 {
 627         unsigned int i, wo_end, last_untagged;
 628
 629         struct object_entry **wo = xmalloc(to_pack.nr_objects * sizeof(*wo));
 630         struct object_entry *objects = to_pack.objects;
 631
 632         for (i = 0; i < to_pack.nr_objects; i++) {
 633                 objects[i].tagged = 0;
 634                 objects[i].filled = 0;
 635                 objects[i].delta_child = NULL;
 636                 objects[i].delta_sibling = NULL;
 637         }
 638
 639         /*
 640          * Fully connect delta_child/delta_sibling network.
 641          * Make sure delta_sibling is sorted in the original
 642          * recency order.
 643          */
 644         for (i = to_pack.nr_objects; i > 0;) {
 645                 struct object_entry *e = &objects[--i];
 646                 if (!e->delta)
 647                         continue;
 648                 /* Mark me as the first child */
 649                 e->delta_sibling = e->delta->delta_child;
 650                 e->delta->delta_child = e;
 651         }
 652
 653         /*
 654          * Mark objects that are at the tip of tags.
 655          */
 656         for_each_tag_ref(mark_tagged, NULL);
 657
 658         /*
 659          * Give the objects in the original recency order until
 660          * we see a tagged tip.
 661          */
 662         for (i = wo_end = 0; i < to_pack.nr_objects; i++) {
 663                 if (objects[i].tagged)
 664                         break;
 665                 add_to_write_order(wo, &wo_end, &objects[i]);
 666         }
 667         last_untagged = i;
 668
 669         /*
 670          * Then fill all the tagged tips.
 671          */
 672         for (; i < to_pack.nr_objects; i++) {
 673                 if (objects[i].tagged)
 674                         add_to_write_order(wo, &wo_end, &objects[i]);
 675         }
 676
 677         /*
 678          * And then all remaining commits and tags.
 679          */
 680         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 681                 if (objects[i].type != OBJ_COMMIT &&
 682                     objects[i].type != OBJ_TAG)
 683                         continue;
 684                 add_to_write_order(wo, &wo_end, &objects[i]);
 685         }
 686
 687         /*
 688          * And then all the trees.
 689          */
 690         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 691                 if (objects[i].type != OBJ_TREE)
 692                         continue;
 693                 add_to_write_order(wo, &wo_end, &objects[i]);
 694         }
 695
 696         /*
 697          * Finally all the rest in really tight order
 698          */
 699         for (i = last_untagged; i < to_pack.nr_objects; i++) {
 700                 if (!objects[i].filled)
 701                         add_family_to_write_order(wo, &wo_end, &objects[i]);
 702         }
 703
 704         if (wo_end != to_pack.nr_objects)
 705                 die("ordered %u objects, expected %"PRIu32, wo_end, to_pack.nr_objects);
 706
 707         return wo;
 708 }
 709
 710 static off_t write_reused_pack(struct sha1file *f)
 711 {
 712         unsigned char buffer[8192];
 713         off_t to_write, total;
 714         int fd;
 715
 716         if (!is_pack_valid(reuse_packfile))
 717                 die("packfile is invalid: %s", reuse_packfile->pack_name);
 718
 719         fd = git_open_noatime(reuse_packfile->pack_name);
 720         if (fd < 0)
 721                 die_errno("unable to open packfile for reuse: %s",
 722                           reuse_packfile->pack_name);
 723
 724         if (lseek(fd, sizeof(struct pack_header), SEEK_SET) == -1)
 725                 die_errno("unable to seek in reused packfile");
 726
 727         if (reuse_packfile_offset < 0)
 728                 reuse_packfile_offset = reuse_packfile->pack_size - 20;
 729
 730         total = to_write = reuse_packfile_offset - sizeof(struct pack_header);
 731
 732         while (to_write) {
 733                 int read_pack = xread(fd, buffer, sizeof(buffer));
 734
 735                 if (read_pack <= 0)
 736                         die_errno("unable to read from reused packfile");
 737
 738                 if (read_pack > to_write)
 739                         read_pack = to_write;
 740
 741                 sha1write(f, buffer, read_pack);
 742                 to_write -= read_pack;
 743
 744                 /*
 745                  * We don't know the actual number of objects written,
 746                  * only how many bytes written, how many bytes total, and
 747                  * how many objects total. So we can fake it by pretending all
 748                  * objects we are writing are the same size. This gives us a
 749                  * smooth progress meter, and at the end it matches the true
 750                  * answer.
 751                  */
 752                 written = reuse_packfile_objects *
 753                                 (((double)(total - to_write)) / total);
 754                 display_progress(progress_state, written);
 755         }
 756
 757         close(fd);
 758         written = reuse_packfile_objects;
 759         display_progress(progress_state, written);
 760         return reuse_packfile_offset - sizeof(struct pack_header);
 761 }
 762
 763 static void write_pack_file(void)
 764 {
 765         uint32_t i = 0, j;
 766         struct sha1file *f;
 767         off_t offset;
 768         uint32_t nr_remaining = nr_result;
 769         time_t last_mtime = 0;
 770         struct object_entry **write_order;
 771
 772         if (progress > pack_to_stdout)
 773                 progress_state = start_progress(_("Writing objects"), nr_result);
 774         written_list = xmalloc(to_pack.nr_objects * sizeof(*written_list));
 775         write_order = compute_write_order();
 776
 777         do {
 778                 unsigned char sha1[20];
 779                 char *pack_tmp_name = NULL;
 780
 781                 if (pack_to_stdout)
 782                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 783                 else
 784                         f = create_tmp_packfile(&pack_tmp_name);
 785
 786                 offset = write_pack_header(f, nr_remaining);
 787
 788                 if (reuse_packfile) {
 789                         off_t packfile_size;
 790                         assert(pack_to_stdout);
 791
 792                         packfile_size = write_reused_pack(f);
 793                         offset += packfile_size;
 794                 }
 795
 796                 nr_written = 0;
 797                 for (; i < to_pack.nr_objects; i++) {
 798                         struct object_entry *e = write_order[i];
 799                         if (write_one(f, e, &offset) == WRITE_ONE_BREAK)
 800                                 break;
 801                         display_progress(progress_state, written);
 802                 }
 803
 804                 /*
 805                  * Did we write the wrong # entries in the header?
 806                  * If so, rewrite it like in fast-import
 807                  */
 808                 if (pack_to_stdout) {
 809                         sha1close(f, sha1, CSUM_CLOSE);
 810                 } else if (nr_written == nr_remaining) {
 811                         sha1close(f, sha1, CSUM_FSYNC);
 812                 } else {
 813                         int fd = sha1close(f, sha1, 0);
 814                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
 815                                                  nr_written, sha1, offset);
 816                         close(fd);
 817                         write_bitmap_index = 0;
 818                 }
 819
 820                 if (!pack_to_stdout) {
 821                         struct stat st;
 822                         struct strbuf tmpname = STRBUF_INIT;
 823
 824                         /*
 825                          * Packs are runtime accessed in their mtime
 826                          * order since newer packs are more likely to contain
 827                          * younger objects.  So if we are creating multiple
 828                          * packs then we should modify the mtime of later ones
 829                          * to preserve this property.
 830                          */
 831                         if (stat(pack_tmp_name, &st) < 0) {
 832                                 warning("failed to stat %s: %s",
 833                                         pack_tmp_name, strerror(errno));
 834                         } else if (!last_mtime) {
 835                                 last_mtime = st.st_mtime;
 836                         } else {
 837                                 struct utimbuf utb;
 838                                 utb.actime = st.st_atime;
 839                                 utb.modtime = --last_mtime;
 840                                 if (utime(pack_tmp_name, &utb) < 0)
 841                                         warning("failed utime() on %s: %s",
 842                                                 pack_tmp_name, strerror(errno));
 843                         }
 844
 845                         strbuf_addf(&tmpname, "%s-", base_name);
 846
 847                         if (write_bitmap_index) {
 848                                 bitmap_writer_set_checksum(sha1);
 849                                 bitmap_writer_build_type_index(written_list, nr_written);
 850                         }
 851
 852                         finish_tmp_packfile(&tmpname, pack_tmp_name,
 853                                             written_list, nr_written,
 854                                             &pack_idx_opts, sha1);
 855
 856                         if (write_bitmap_index) {
 857                                 strbuf_addf(&tmpname, "%s.bitmap", sha1_to_hex(sha1));
 858
 859                                 stop_progress(&progress_state);
 860
 861                                 bitmap_writer_show_progress(progress);
 862                                 bitmap_writer_reuse_bitmaps(&to_pack);
 863                                 bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
 864                                 bitmap_writer_build(&to_pack);
 865                                 bitmap_writer_finish(written_list, nr_written,
 866                                                      tmpname.buf, write_bitmap_options);
 867                                 write_bitmap_index = 0;
 868                         }
 869
 870                         strbuf_release(&tmpname);
 871                         free(pack_tmp_name);
 872                         puts(sha1_to_hex(sha1));
 873                 }
 874
 875                 /* mark written objects as written to previous pack */
 876                 for (j = 0; j < nr_written; j++) {
 877                         written_list[j]->offset = (off_t)-1;
 878                 }
 879                 nr_remaining -= nr_written;
 880         } while (nr_remaining && i < to_pack.nr_objects);
 881
 882         free(written_list);
 883         free(write_order);
 884         stop_progress(&progress_state);
 885         if (written != nr_result)
 886                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
 887                         written, nr_result);
 888 }
 889
 890 static void setup_delta_attr_check(struct git_attr_check *check)
 891 {
 892         static struct git_attr *attr_delta;
 893
 894         if (!attr_delta)
 895                 attr_delta = git_attr("delta");
 896
 897         check[0].attr = attr_delta;
 898 }
 899
 900 static int no_try_delta(const char *path)
 901 {
 902         struct git_attr_check check[1];
 903
 904         setup_delta_attr_check(check);
 905         if (git_check_attr(path, ARRAY_SIZE(check), check))
 906                 return 0;
 907         if (ATTR_FALSE(check->value))
 908                 return 1;
 909         return 0;
 910 }
 911
 912 /*
 913  * When adding an object, check whether we have already added it
 914  * to our packing list. If so, we can skip. However, if we are
 915  * being asked to excludei t, but the previous mention was to include
 916  * it, make sure to adjust its flags and tweak our numbers accordingly.
 917  *
 918  * As an optimization, we pass out the index position where we would have
 919  * found the item, since that saves us from having to look it up again a
 920  * few lines later when we want to add the new entry.
 921  */
 922 static int have_duplicate_entry(const unsigned char *sha1,
 923                                 int exclude,
 924                                 uint32_t *index_pos)
 925 {
 926         struct object_entry *entry;
 927
 928         entry = packlist_find(&to_pack, sha1, index_pos);
 929         if (!entry)
 930                 return 0;
 931
 932         if (exclude) {
 933                 if (!entry->preferred_base)
 934                         nr_result--;
 935                 entry->preferred_base = 1;
 936         }
 937
 938         return 1;
 939 }
 940
 941 /*
 942  * Check whether we want the object in the pack (e.g., we do not want
 943  * objects found in non-local stores if the "--local" option was used).
 944  *
 945  * As a side effect of this check, we will find the packed version of this
 946  * object, if any. We therefore pass out the pack information to avoid having
 947  * to look it up again later.
 948  */
 949 static int want_object_in_pack(const unsigned char *sha1,
 950                                int exclude,
 951                                struct packed_git **found_pack,
 952                                off_t *found_offset)
 953 {
 954         struct packed_git *p;
 955
 956         if (!exclude && local && has_loose_object_nonlocal(sha1))
 957                 return 0;
 958
 959         *found_pack = NULL;
 960         *found_offset = 0;
 961
 962         for (p = packed_git; p; p = p->next) {
 963                 off_t offset = find_pack_entry_one(sha1, p);
 964                 if (offset) {
 965                         if (!*found_pack) {
 966                                 if (!is_pack_valid(p)) {
 967                                         warning("packfile %s cannot be accessed", p->pack_name);
 968                                         continue;
 969                                 }
 970                                 *found_offset = offset;
 971                                 *found_pack = p;
 972                         }
 973                         if (exclude)
 974                                 return 1;
 975                         if (incremental)
 976                                 return 0;
 977                         if (local && !p->pack_local)
 978                                 return 0;
 979                         if (ignore_packed_keep && p->pack_local && p->pack_keep)
 980                                 return 0;
 981                 }
 982         }
 983
 984         return 1;
 985 }
 986
 987 static void create_object_entry(const unsigned char *sha1,
 988                                 enum object_type type,
 989                                 uint32_t hash,
 990                                 int exclude,
 991                                 int no_try_delta,
 992                                 uint32_t index_pos,
 993                                 struct packed_git *found_pack,
 994                                 off_t found_offset)
 995 {
 996         struct object_entry *entry;
 997
 998         entry = packlist_alloc(&to_pack, sha1, index_pos);
 999         entry->hash = hash;
1000         if (type)
1001                 entry->type = type;
1002         if (exclude)
1003                 entry->preferred_base = 1;
1004         else
1005                 nr_result++;
1006         if (found_pack) {
1007                 entry->in_pack = found_pack;
1008                 entry->in_pack_offset = found_offset;
1009         }
1010
1011         entry->no_try_delta = no_try_delta;
1012 }
1013
1014 static const char no_closure_warning[] = N_(
1015 "disabling bitmap writing, as some objects are not being packed"
1016 );
1017
1018 static int add_object_entry(const unsigned char *sha1, enum object_type type,
1019                             const char *name, int exclude)
1020 {
1021         struct packed_git *found_pack;
1022         off_t found_offset;
1023         uint32_t index_pos;
1024
1025         if (have_duplicate_entry(sha1, exclude, &index_pos))
1026                 return 0;
1027
1028         if (!want_object_in_pack(sha1, exclude, &found_pack, &found_offset)) {
1029                 /* The pack is missing an object, so it will not have closure */
1030                 if (write_bitmap_index) {
1031                         warning(_(no_closure_warning));
1032                         write_bitmap_index = 0;
1033                 }
1034                 return 0;
1035         }
1036
1037         create_object_entry(sha1, type, pack_name_hash(name),
1038                             exclude, name && no_try_delta(name),
1039                             index_pos, found_pack, found_offset);
1040
1041         display_progress(progress_state, nr_result);
1042         return 1;
1043 }
1044
1045 static int add_object_entry_from_bitmap(const unsigned char *sha1,
1046                                         enum object_type type,
1047                                         int flags, uint32_t name_hash,
1048                                         struct packed_git *pack, off_t offset)
1049 {
1050         uint32_t index_pos;
1051
1052         if (have_duplicate_entry(sha1, 0, &index_pos))
1053                 return 0;
1054
1055         create_object_entry(sha1, type, name_hash, 0, 0, index_pos, pack, offset);
1056
1057         display_progress(progress_state, nr_result);
1058         return 1;
1059 }
1060
1061 struct pbase_tree_cache {
1062         unsigned char sha1[20];
1063         int ref;
1064         int temporary;
1065         void *tree_data;
1066         unsigned long tree_size;
1067 };
1068
1069 static struct pbase_tree_cache *(pbase_tree_cache[256]);
1070 static int pbase_tree_cache_ix(const unsigned char *sha1)
1071 {
1072         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
1073 }
1074 static int pbase_tree_cache_ix_incr(int ix)
1075 {
1076         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
1077 }
1078
1079 static struct pbase_tree {
1080         struct pbase_tree *next;
1081         /* This is a phony "cache" entry; we are not
1082          * going to evict it or find it through _get()
1083          * mechanism -- this is for the toplevel node that
1084          * would almost always change with any commit.
1085          */
1086         struct pbase_tree_cache pcache;
1087 } *pbase_tree;
1088
1089 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
1090 {
1091         struct pbase_tree_cache *ent, *nent;
1092         void *data;
1093         unsigned long size;
1094         enum object_type type;
1095         int neigh;
1096         int my_ix = pbase_tree_cache_ix(sha1);
1097         int available_ix = -1;
1098
1099         /* pbase-tree-cache acts as a limited hashtable.
1100          * your object will be found at your index or within a few
1101          * slots after that slot if it is cached.
1102          */
1103         for (neigh = 0; neigh < 8; neigh++) {
1104                 ent = pbase_tree_cache[my_ix];
1105                 if (ent && !hashcmp(ent->sha1, sha1)) {
1106                         ent->ref++;
1107                         return ent;
1108                 }
1109                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
1110                          ((0 <= available_ix) &&
1111                           (!ent && pbase_tree_cache[available_ix])))
1112                         available_ix = my_ix;
1113                 if (!ent)
1114                         break;
1115                 my_ix = pbase_tree_cache_ix_incr(my_ix);
1116         }
1117
1118         /* Did not find one.  Either we got a bogus request or
1119          * we need to read and perhaps cache.
1120          */
1121         data = read_sha1_file(sha1, &type, &size);
1122         if (!data)
1123                 return NULL;
1124         if (type != OBJ_TREE) {
1125                 free(data);
1126                 return NULL;
1127         }
1128
1129         /* We need to either cache or return a throwaway copy */
1130
1131         if (available_ix < 0)
1132                 ent = NULL;
1133         else {
1134                 ent = pbase_tree_cache[available_ix];
1135                 my_ix = available_ix;
1136         }
1137
1138         if (!ent) {
1139                 nent = xmalloc(sizeof(*nent));
1140                 nent->temporary = (available_ix < 0);
1141         }
1142         else {
1143                 /* evict and reuse */
1144                 free(ent->tree_data);
1145                 nent = ent;
1146         }
1147         hashcpy(nent->sha1, sha1);
1148         nent->tree_data = data;
1149         nent->tree_size = size;
1150         nent->ref = 1;
1151         if (!nent->temporary)
1152                 pbase_tree_cache[my_ix] = nent;
1153         return nent;
1154 }
1155
1156 static void pbase_tree_put(struct pbase_tree_cache *cache)
1157 {
1158         if (!cache->temporary) {
1159                 cache->ref--;
1160                 return;
1161         }
1162         free(cache->tree_data);
1163         free(cache);
1164 }
1165
1166 static int name_cmp_len(const char *name)
1167 {
1168         int i;
1169         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
1170                 ;
1171         return i;
1172 }
1173
1174 static void add_pbase_object(struct tree_desc *tree,
1175                              const char *name,
1176                              int cmplen,
1177                              const char *fullname)
1178 {
1179         struct name_entry entry;
1180         int cmp;
1181
1182         while (tree_entry(tree,&entry)) {
1183                 if (S_ISGITLINK(entry.mode))
1184                         continue;
1185                 cmp = tree_entry_len(&entry) != cmplen ? 1 :
1186                       memcmp(name, entry.path, cmplen);
1187                 if (cmp > 0)
1188                         continue;
1189                 if (cmp < 0)
1190                         return;
1191                 if (name[cmplen] != '/') {
1192                         add_object_entry(entry.sha1,
1193                                          object_type(entry.mode),
1194                                          fullname, 1);
1195                         return;
1196                 }
1197                 if (S_ISDIR(entry.mode)) {
1198                         struct tree_desc sub;
1199                         struct pbase_tree_cache *tree;
1200                         const char *down = name+cmplen+1;
1201                         int downlen = name_cmp_len(down);
1202
1203                         tree = pbase_tree_get(entry.sha1);
1204                         if (!tree)
1205                                 return;
1206                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1207
1208                         add_pbase_object(&sub, down, downlen, fullname);
1209                         pbase_tree_put(tree);
1210                 }
1211         }
1212 }
1213
1214 static unsigned *done_pbase_paths;
1215 static int done_pbase_paths_num;
1216 static int done_pbase_paths_alloc;
1217 static int done_pbase_path_pos(unsigned hash)
1218 {
1219         int lo = 0;
1220         int hi = done_pbase_paths_num;
1221         while (lo < hi) {
1222                 int mi = (hi + lo) / 2;
1223                 if (done_pbase_paths[mi] == hash)
1224                         return mi;
1225                 if (done_pbase_paths[mi] < hash)
1226                         hi = mi;
1227                 else
1228                         lo = mi + 1;
1229         }
1230         return -lo-1;
1231 }
1232
1233 static int check_pbase_path(unsigned hash)
1234 {
1235         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
1236         if (0 <= pos)
1237                 return 1;
1238         pos = -pos - 1;
1239         ALLOC_GROW(done_pbase_paths,
1240                    done_pbase_paths_num + 1,
1241                    done_pbase_paths_alloc);
1242         done_pbase_paths_num++;
1243         if (pos < done_pbase_paths_num)
1244                 memmove(done_pbase_paths + pos + 1,
1245                         done_pbase_paths + pos,
1246                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
1247         done_pbase_paths[pos] = hash;
1248         return 0;
1249 }
1250
1251 static void add_preferred_base_object(const char *name)
1252 {
1253         struct pbase_tree *it;
1254         int cmplen;
1255         unsigned hash = pack_name_hash(name);
1256
1257         if (!num_preferred_base || check_pbase_path(hash))
1258                 return;
1259
1260         cmplen = name_cmp_len(name);
1261         for (it = pbase_tree; it; it = it->next) {
1262                 if (cmplen == 0) {
1263                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
1264                 }
1265                 else {
1266                         struct tree_desc tree;
1267                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1268                         add_pbase_object(&tree, name, cmplen, name);
1269                 }
1270         }
1271 }
1272
1273 static void add_preferred_base(unsigned char *sha1)
1274 {
1275         struct pbase_tree *it;
1276         void *data;
1277         unsigned long size;
1278         unsigned char tree_sha1[20];
1279
1280         if (window <= num_preferred_base++)
1281                 return;
1282
1283         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
1284         if (!data)
1285                 return;
1286
1287         for (it = pbase_tree; it; it = it->next) {
1288                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
1289                         free(data);
1290                         return;
1291                 }
1292         }
1293
1294         it = xcalloc(1, sizeof(*it));
1295         it->next = pbase_tree;
1296         pbase_tree = it;
1297
1298         hashcpy(it->pcache.sha1, tree_sha1);
1299         it->pcache.tree_data = data;
1300         it->pcache.tree_size = size;
1301 }
1302
1303 static void cleanup_preferred_base(void)
1304 {
1305         struct pbase_tree *it;
1306         unsigned i;
1307
1308         it = pbase_tree;
1309         pbase_tree = NULL;
1310         while (it) {
1311                 struct pbase_tree *this = it;
1312                 it = this->next;
1313                 free(this->pcache.tree_data);
1314                 free(this);
1315         }
1316
1317         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1318                 if (!pbase_tree_cache[i])
1319                         continue;
1320                 free(pbase_tree_cache[i]->tree_data);
1321                 free(pbase_tree_cache[i]);
1322                 pbase_tree_cache[i] = NULL;
1323         }
1324
1325         free(done_pbase_paths);
1326         done_pbase_paths = NULL;
1327         done_pbase_paths_num = done_pbase_paths_alloc = 0;
1328 }
1329
1330 static void check_object(struct object_entry *entry)
1331 {
1332         if (entry->in_pack) {
1333                 struct packed_git *p = entry->in_pack;
1334                 struct pack_window *w_curs = NULL;
1335                 const unsigned char *base_ref = NULL;
1336                 struct object_entry *base_entry;
1337                 unsigned long used, used_0;
1338                 unsigned long avail;
1339                 off_t ofs;
1340                 unsigned char *buf, c;
1341
1342                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1343
1344                 /*
1345                  * We want in_pack_type even if we do not reuse delta
1346                  * since non-delta representations could still be reused.
1347                  */
1348                 used = unpack_object_header_buffer(buf, avail,
1349                                                    &entry->in_pack_type,
1350                                                    &entry->size);
1351                 if (used == 0)
1352                         goto give_up;
1353
1354                 /*
1355                  * Determine if this is a delta and if so whether we can
1356                  * reuse it or not.  Otherwise let's find out as cheaply as
1357                  * possible what the actual type and size for this object is.
1358                  */
1359                 switch (entry->in_pack_type) {
1360                 default:
1361                         /* Not a delta hence we've already got all we need. */
1362                         entry->type = entry->in_pack_type;
1363                         entry->in_pack_header_size = used;
1364                         if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1365                                 goto give_up;
1366                         unuse_pack(&w_curs);
1367                         return;
1368                 case OBJ_REF_DELTA:
1369                         if (reuse_delta && !entry->preferred_base)
1370                                 base_ref = use_pack(p, &w_curs,
1371                                                 entry->in_pack_offset + used, NULL);
1372                         entry->in_pack_header_size = used + 20;
1373                         break;
1374                 case OBJ_OFS_DELTA:
1375                         buf = use_pack(p, &w_curs,
1376                                        entry->in_pack_offset + used, NULL);
1377                         used_0 = 0;
1378                         c = buf[used_0++];
1379                         ofs = c & 127;
1380                         while (c & 128) {
1381                                 ofs += 1;
1382                                 if (!ofs || MSB(ofs, 7)) {
1383                                         error("delta base offset overflow in pack for %s",
1384                                               sha1_to_hex(entry->idx.sha1));
1385                                         goto give_up;
1386                                 }
1387                                 c = buf[used_0++];
1388                                 ofs = (ofs << 7) + (c & 127);
1389                         }
1390                         ofs = entry->in_pack_offset - ofs;
1391                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1392                                 error("delta base offset out of bound for %s",
1393                                       sha1_to_hex(entry->idx.sha1));
1394                                 goto give_up;
1395                         }
1396                         if (reuse_delta && !entry->preferred_base) {
1397                                 struct revindex_entry *revidx;
1398                                 revidx = find_pack_revindex(p, ofs);
1399                                 if (!revidx)
1400                                         goto give_up;
1401                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1402                         }
1403                         entry->in_pack_header_size = used + used_0;
1404                         break;
1405                 }
1406
1407                 if (base_ref && (base_entry = packlist_find(&to_pack, base_ref, NULL))) {
1408                         /*
1409                          * If base_ref was set above that means we wish to
1410                          * reuse delta data, and we even found that base
1411                          * in the list of objects we want to pack. Goodie!
1412                          *
1413                          * Depth value does not matter - find_deltas() will
1414                          * never consider reused delta as the base object to
1415                          * deltify other objects against, in order to avoid
1416                          * circular deltas.
1417                          */
1418                         entry->type = entry->in_pack_type;
1419                         entry->delta = base_entry;
1420                         entry->delta_size = entry->size;
1421                         entry->delta_sibling = base_entry->delta_child;
1422                         base_entry->delta_child = entry;
1423                         unuse_pack(&w_curs);
1424                         return;
1425                 }
1426
1427                 if (entry->type) {
1428                         /*
1429                          * This must be a delta and we already know what the
1430                          * final object type is.  Let's extract the actual
1431                          * object size from the delta header.
1432                          */
1433                         entry->size = get_size_from_delta(p, &w_curs,
1434                                         entry->in_pack_offset + entry->in_pack_header_size);
1435                         if (entry->size == 0)
1436                                 goto give_up;
1437                         unuse_pack(&w_curs);
1438                         return;
1439                 }
1440
1441                 /*
1442                  * No choice but to fall back to the recursive delta walk
1443                  * with sha1_object_info() to find about the object type
1444                  * at this point...
1445                  */
1446                 give_up:
1447                 unuse_pack(&w_curs);
1448         }
1449
1450         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1451         /*
1452          * The error condition is checked in prepare_pack().  This is
1453          * to permit a missing preferred base object to be ignored
1454          * as a preferred base.  Doing so can result in a larger
1455          * pack file, but the transfer will still take place.
1456          */
1457 }
1458
1459 static int pack_offset_sort(const void *_a, const void *_b)
1460 {
1461         const struct object_entry *a = *(struct object_entry **)_a;
1462         const struct object_entry *b = *(struct object_entry **)_b;
1463
1464         /* avoid filesystem trashing with loose objects */
1465         if (!a->in_pack && !b->in_pack)
1466                 return hashcmp(a->idx.sha1, b->idx.sha1);
1467
1468         if (a->in_pack < b->in_pack)
1469                 return -1;
1470         if (a->in_pack > b->in_pack)
1471                 return 1;
1472         return a->in_pack_offset < b->in_pack_offset ? -1 :
1473                         (a->in_pack_offset > b->in_pack_offset);
1474 }
1475
1476 static void get_object_details(void)
1477 {
1478         uint32_t i;
1479         struct object_entry **sorted_by_offset;
1480
1481         sorted_by_offset = xcalloc(to_pack.nr_objects, sizeof(struct object_entry *));
1482         for (i = 0; i < to_pack.nr_objects; i++)
1483                 sorted_by_offset[i] = to_pack.objects + i;
1484         qsort(sorted_by_offset, to_pack.nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1485
1486         for (i = 0; i < to_pack.nr_objects; i++) {
1487                 struct object_entry *entry = sorted_by_offset[i];
1488                 check_object(entry);
1489                 if (big_file_threshold < entry->size)
1490                         entry->no_try_delta = 1;
1491         }
1492
1493         free(sorted_by_offset);
1494 }
1495
1496 /*
1497  * We search for deltas in a list sorted by type, by filename hash, and then
1498  * by size, so that we see progressively smaller and smaller files.
1499  * That's because we prefer deltas to be from the bigger file
1500  * to the smaller -- deletes are potentially cheaper, but perhaps
1501  * more importantly, the bigger file is likely the more recent
1502  * one.  The deepest deltas are therefore the oldest objects which are
1503  * less susceptible to be accessed often.
1504  */
1505 static int type_size_sort(const void *_a, const void *_b)
1506 {
1507         const struct object_entry *a = *(struct object_entry **)_a;
1508         const struct object_entry *b = *(struct object_entry **)_b;
1509
1510         if (a->type > b->type)
1511                 return -1;
1512         if (a->type < b->type)
1513                 return 1;
1514         if (a->hash > b->hash)
1515                 return -1;
1516         if (a->hash < b->hash)
1517                 return 1;
1518         if (a->preferred_base > b->preferred_base)
1519                 return -1;
1520         if (a->preferred_base < b->preferred_base)
1521                 return 1;
1522         if (a->size > b->size)
1523                 return -1;
1524         if (a->size < b->size)
1525                 return 1;
1526         return a < b ? -1 : (a > b);  /* newest first */
1527 }
1528
1529 struct unpacked {
1530         struct object_entry *entry;
1531         void *data;
1532         struct delta_index *index;
1533         unsigned depth;
1534 };
1535
1536 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1537                            unsigned long delta_size)
1538 {
1539         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1540                 return 0;
1541
1542         if (delta_size < cache_max_small_delta_size)
1543                 return 1;
1544
1545         /* cache delta, if objects are large enough compared to delta size */
1546         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1547                 return 1;
1548
1549         return 0;
1550 }
1551
1552 #ifndef NO_PTHREADS
1553
1554 static pthread_mutex_t read_mutex;
1555 #define read_lock()             pthread_mutex_lock(&read_mutex)
1556 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1557
1558 static pthread_mutex_t cache_mutex;
1559 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1560 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1561
1562 static pthread_mutex_t progress_mutex;
1563 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1564 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1565
1566 #else
1567
1568 #define read_lock()             (void)0
1569 #define read_unlock()           (void)0
1570 #define cache_lock()            (void)0
1571 #define cache_unlock()          (void)0
1572 #define progress_lock()         (void)0
1573 #define progress_unlock()       (void)0
1574
1575 #endif
1576
1577 static int try_delta(struct unpacked *trg, struct unpacked *src,
1578                      unsigned max_depth, unsigned long *mem_usage)
1579 {
1580         struct object_entry *trg_entry = trg->entry;
1581         struct object_entry *src_entry = src->entry;
1582         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1583         unsigned ref_depth;
1584         enum object_type type;
1585         void *delta_buf;
1586
1587         /* Don't bother doing diffs between different types */
1588         if (trg_entry->type != src_entry->type)
1589                 return -1;
1590
1591         /*
1592          * We do not bother to try a delta that we discarded on an
1593          * earlier try, but only when reusing delta data.  Note that
1594          * src_entry that is marked as the preferred_base should always
1595          * be considered, as even if we produce a suboptimal delta against
1596          * it, we will still save the transfer cost, as we already know
1597          * the other side has it and we won't send src_entry at all.
1598          */
1599         if (reuse_delta && trg_entry->in_pack &&
1600             trg_entry->in_pack == src_entry->in_pack &&
1601             !src_entry->preferred_base &&
1602             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1603             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1604                 return 0;
1605
1606         /* Let's not bust the allowed depth. */
1607         if (src->depth >= max_depth)
1608                 return 0;
1609
1610         /* Now some size filtering heuristics. */
1611         trg_size = trg_entry->size;
1612         if (!trg_entry->delta) {
1613                 max_size = trg_size/2 - 20;
1614                 ref_depth = 1;
1615         } else {
1616                 max_size = trg_entry->delta_size;
1617                 ref_depth = trg->depth;
1618         }
1619         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1620                                                 (max_depth - ref_depth + 1);
1621         if (max_size == 0)
1622                 return 0;
1623         src_size = src_entry->size;
1624         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1625         if (sizediff >= max_size)
1626                 return 0;
1627         if (trg_size < src_size / 32)
1628                 return 0;
1629
1630         /* Load data if not already done */
1631         if (!trg->data) {
1632                 read_lock();
1633                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1634                 read_unlock();
1635                 if (!trg->data)
1636                         die("object %s cannot be read",
1637                             sha1_to_hex(trg_entry->idx.sha1));
1638                 if (sz != trg_size)
1639                         die("object %s inconsistent object length (%lu vs %lu)",
1640                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1641                 *mem_usage += sz;
1642         }
1643         if (!src->data) {
1644                 read_lock();
1645                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1646                 read_unlock();
1647                 if (!src->data) {
1648                         if (src_entry->preferred_base) {
1649                                 static int warned = 0;
1650                                 if (!warned++)
1651                                         warning("object %s cannot be read",
1652                                                 sha1_to_hex(src_entry->idx.sha1));
1653                                 /*
1654                                  * Those objects are not included in the
1655                                  * resulting pack.  Be resilient and ignore
1656                                  * them if they can't be read, in case the
1657                                  * pack could be created nevertheless.
1658                                  */
1659                                 return 0;
1660                         }
1661                         die("object %s cannot be read",
1662                             sha1_to_hex(src_entry->idx.sha1));
1663                 }
1664                 if (sz != src_size)
1665                         die("object %s inconsistent object length (%lu vs %lu)",
1666                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1667                 *mem_usage += sz;
1668         }
1669         if (!src->index) {
1670                 src->index = create_delta_index(src->data, src_size);
1671                 if (!src->index) {
1672                         static int warned = 0;
1673                         if (!warned++)
1674                                 warning("suboptimal pack - out of memory");
1675                         return 0;
1676                 }
1677                 *mem_usage += sizeof_delta_index(src->index);
1678         }
1679
1680         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1681         if (!delta_buf)
1682                 return 0;
1683
1684         if (trg_entry->delta) {
1685                 /* Prefer only shallower same-sized deltas. */
1686                 if (delta_size == trg_entry->delta_size &&
1687                     src->depth + 1 >= trg->depth) {
1688                         free(delta_buf);
1689                         return 0;
1690                 }
1691         }
1692
1693         /*
1694          * Handle memory allocation outside of the cache
1695          * accounting lock.  Compiler will optimize the strangeness
1696          * away when NO_PTHREADS is defined.
1697          */
1698         free(trg_entry->delta_data);
1699         cache_lock();
1700         if (trg_entry->delta_data) {
1701                 delta_cache_size -= trg_entry->delta_size;
1702                 trg_entry->delta_data = NULL;
1703         }
1704         if (delta_cacheable(src_size, trg_size, delta_size)) {
1705                 delta_cache_size += delta_size;
1706                 cache_unlock();
1707                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1708         } else {
1709                 cache_unlock();
1710                 free(delta_buf);
1711         }
1712
1713         trg_entry->delta = src_entry;
1714         trg_entry->delta_size = delta_size;
1715         trg->depth = src->depth + 1;
1716
1717         return 1;
1718 }
1719
1720 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1721 {
1722         struct object_entry *child = me->delta_child;
1723         unsigned int m = n;
1724         while (child) {
1725                 unsigned int c = check_delta_limit(child, n + 1);
1726                 if (m < c)
1727                         m = c;
1728                 child = child->delta_sibling;
1729         }
1730         return m;
1731 }
1732
1733 static unsigned long free_unpacked(struct unpacked *n)
1734 {
1735         unsigned long freed_mem = sizeof_delta_index(n->index);
1736         free_delta_index(n->index);
1737         n->index = NULL;
1738         if (n->data) {
1739                 freed_mem += n->entry->size;
1740                 free(n->data);
1741                 n->data = NULL;
1742         }
1743         n->entry = NULL;
1744         n->depth = 0;
1745         return freed_mem;
1746 }
1747
1748 static void find_deltas(struct object_entry **list, unsigned *list_size,
1749                         int window, int depth, unsigned *processed)
1750 {
1751         uint32_t i, idx = 0, count = 0;
1752         struct unpacked *array;
1753         unsigned long mem_usage = 0;
1754
1755         array = xcalloc(window, sizeof(struct unpacked));
1756
1757         for (;;) {
1758                 struct object_entry *entry;
1759                 struct unpacked *n = array + idx;
1760                 int j, max_depth, best_base = -1;
1761
1762                 progress_lock();
1763                 if (!*list_size) {
1764                         progress_unlock();
1765                         break;
1766                 }
1767                 entry = *list++;
1768                 (*list_size)--;
1769                 if (!entry->preferred_base) {
1770                         (*processed)++;
1771                         display_progress(progress_state, *processed);
1772                 }
1773                 progress_unlock();
1774
1775                 mem_usage -= free_unpacked(n);
1776                 n->entry = entry;
1777
1778                 while (window_memory_limit &&
1779                        mem_usage > window_memory_limit &&
1780                        count > 1) {
1781                         uint32_t tail = (idx + window - count) % window;
1782                         mem_usage -= free_unpacked(array + tail);
1783                         count--;
1784                 }
1785
1786                 /* We do not compute delta to *create* objects we are not
1787                  * going to pack.
1788                  */
1789                 if (entry->preferred_base)
1790                         goto next;
1791
1792                 /*
1793                  * If the current object is at pack edge, take the depth the
1794                  * objects that depend on the current object into account
1795                  * otherwise they would become too deep.
1796                  */
1797                 max_depth = depth;
1798                 if (entry->delta_child) {
1799                         max_depth -= check_delta_limit(entry, 0);
1800                         if (max_depth <= 0)
1801                                 goto next;
1802                 }
1803
1804                 j = window;
1805                 while (--j > 0) {
1806                         int ret;
1807                         uint32_t other_idx = idx + j;
1808                         struct unpacked *m;
1809                         if (other_idx >= window)
1810                                 other_idx -= window;
1811                         m = array + other_idx;
1812                         if (!m->entry)
1813                                 break;
1814                         ret = try_delta(n, m, max_depth, &mem_usage);
1815                         if (ret < 0)
1816                                 break;
1817                         else if (ret > 0)
1818                                 best_base = other_idx;
1819                 }
1820
1821                 /*
1822                  * If we decided to cache the delta data, then it is best
1823                  * to compress it right away.  First because we have to do
1824                  * it anyway, and doing it here while we're threaded will
1825                  * save a lot of time in the non threaded write phase,
1826                  * as well as allow for caching more deltas within
1827                  * the same cache size limit.
1828                  * ...
1829                  * But only if not writing to stdout, since in that case
1830                  * the network is most likely throttling writes anyway,
1831                  * and therefore it is best to go to the write phase ASAP
1832                  * instead, as we can afford spending more time compressing
1833                  * between writes at that moment.
1834                  */
1835                 if (entry->delta_data && !pack_to_stdout) {
1836                         entry->z_delta_size = do_compress(&entry->delta_data,
1837                                                           entry->delta_size);
1838                         cache_lock();
1839                         delta_cache_size -= entry->delta_size;
1840                         delta_cache_size += entry->z_delta_size;
1841                         cache_unlock();
1842                 }
1843
1844                 /* if we made n a delta, and if n is already at max
1845                  * depth, leaving it in the window is pointless.  we
1846                  * should evict it first.
1847                  */
1848                 if (entry->delta && max_depth <= n->depth)
1849                         continue;
1850
1851                 /*
1852                  * Move the best delta base up in the window, after the
1853                  * currently deltified object, to keep it longer.  It will
1854                  * be the first base object to be attempted next.
1855                  */
1856                 if (entry->delta) {
1857                         struct unpacked swap = array[best_base];
1858                         int dist = (window + idx - best_base) % window;
1859                         int dst = best_base;
1860                         while (dist--) {
1861                                 int src = (dst + 1) % window;
1862                                 array[dst] = array[src];
1863                                 dst = src;
1864                         }
1865                         array[dst] = swap;
1866                 }
1867
1868                 next:
1869                 idx++;
1870                 if (count + 1 < window)
1871                         count++;
1872                 if (idx >= window)
1873                         idx = 0;
1874         }
1875
1876         for (i = 0; i < window; ++i) {
1877                 free_delta_index(array[i].index);
1878                 free(array[i].data);
1879         }
1880         free(array);
1881 }
1882
1883 #ifndef NO_PTHREADS
1884
1885 static void try_to_free_from_threads(size_t size)
1886 {
1887         read_lock();
1888         release_pack_memory(size);
1889         read_unlock();
1890 }
1891
1892 static try_to_free_t old_try_to_free_routine;
1893
1894 /*
1895  * The main thread waits on the condition that (at least) one of the workers
1896  * has stopped working (which is indicated in the .working member of
1897  * struct thread_params).
1898  * When a work thread has completed its work, it sets .working to 0 and
1899  * signals the main thread and waits on the condition that .data_ready
1900  * becomes 1.
1901  */
1902
1903 struct thread_params {
1904         pthread_t thread;
1905         struct object_entry **list;
1906         unsigned list_size;
1907         unsigned remaining;
1908         int window;
1909         int depth;
1910         int working;
1911         int data_ready;
1912         pthread_mutex_t mutex;
1913         pthread_cond_t cond;
1914         unsigned *processed;
1915 };
1916
1917 static pthread_cond_t progress_cond;
1918
1919 /*
1920  * Mutex and conditional variable can't be statically-initialized on Windows.
1921  */
1922 static void init_threaded_search(void)
1923 {
1924         init_recursive_mutex(&read_mutex);
1925         pthread_mutex_init(&cache_mutex, NULL);
1926         pthread_mutex_init(&progress_mutex, NULL);
1927         pthread_cond_init(&progress_cond, NULL);
1928         old_try_to_free_routine = set_try_to_free_routine(try_to_free_from_threads);
1929 }
1930
1931 static void cleanup_threaded_search(void)
1932 {
1933         set_try_to_free_routine(old_try_to_free_routine);
1934         pthread_cond_destroy(&progress_cond);
1935         pthread_mutex_destroy(&read_mutex);
1936         pthread_mutex_destroy(&cache_mutex);
1937         pthread_mutex_destroy(&progress_mutex);
1938 }
1939
1940 static void *threaded_find_deltas(void *arg)
1941 {
1942         struct thread_params *me = arg;
1943
1944         while (me->remaining) {
1945                 find_deltas(me->list, &me->remaining,
1946                             me->window, me->depth, me->processed);
1947
1948                 progress_lock();
1949                 me->working = 0;
1950                 pthread_cond_signal(&progress_cond);
1951                 progress_unlock();
1952
1953                 /*
1954                  * We must not set ->data_ready before we wait on the
1955                  * condition because the main thread may have set it to 1
1956                  * before we get here. In order to be sure that new
1957                  * work is available if we see 1 in ->data_ready, it
1958                  * was initialized to 0 before this thread was spawned
1959                  * and we reset it to 0 right away.
1960                  */
1961                 pthread_mutex_lock(&me->mutex);
1962                 while (!me->data_ready)
1963                         pthread_cond_wait(&me->cond, &me->mutex);
1964                 me->data_ready = 0;
1965                 pthread_mutex_unlock(&me->mutex);
1966         }
1967         /* leave ->working 1 so that this doesn't get more work assigned */
1968         return NULL;
1969 }
1970
1971 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1972                            int window, int depth, unsigned *processed)
1973 {
1974         struct thread_params *p;
1975         int i, ret, active_threads = 0;
1976
1977         init_threaded_search();
1978
1979         if (delta_search_threads <= 1) {
1980                 find_deltas(list, &list_size, window, depth, processed);
1981                 cleanup_threaded_search();
1982                 return;
1983         }
1984         if (progress > pack_to_stdout)
1985                 fprintf(stderr, "Delta compression using up to %d threads.\n",
1986                                 delta_search_threads);
1987         p = xcalloc(delta_search_threads, sizeof(*p));
1988
1989         /* Partition the work amongst work threads. */
1990         for (i = 0; i < delta_search_threads; i++) {
1991                 unsigned sub_size = list_size / (delta_search_threads - i);
1992
1993                 /* don't use too small segments or no deltas will be found */
1994                 if (sub_size < 2*window && i+1 < delta_search_threads)
1995                         sub_size = 0;
1996
1997                 p[i].window = window;
1998                 p[i].depth = depth;
1999                 p[i].processed = processed;
2000                 p[i].working = 1;
2001                 p[i].data_ready = 0;
2002
2003                 /* try to split chunks on "path" boundaries */
2004                 while (sub_size && sub_size < list_size &&
2005                        list[sub_size]->hash &&
2006                        list[sub_size]->hash == list[sub_size-1]->hash)
2007                         sub_size++;
2008
2009                 p[i].list = list;
2010                 p[i].list_size = sub_size;
2011                 p[i].remaining = sub_size;
2012
2013                 list += sub_size;
2014                 list_size -= sub_size;
2015         }
2016
2017         /* Start work threads. */
2018         for (i = 0; i < delta_search_threads; i++) {
2019                 if (!p[i].list_size)
2020                         continue;
2021                 pthread_mutex_init(&p[i].mutex, NULL);
2022                 pthread_cond_init(&p[i].cond, NULL);
2023                 ret = pthread_create(&p[i].thread, NULL,
2024                                      threaded_find_deltas, &p[i]);
2025                 if (ret)
2026                         die("unable to create thread: %s", strerror(ret));
2027                 active_threads++;
2028         }
2029
2030         /*
2031          * Now let's wait for work completion.  Each time a thread is done
2032          * with its work, we steal half of the remaining work from the
2033          * thread with the largest number of unprocessed objects and give
2034          * it to that newly idle thread.  This ensure good load balancing
2035          * until the remaining object list segments are simply too short
2036          * to be worth splitting anymore.
2037          */
2038         while (active_threads) {
2039                 struct thread_params *target = NULL;
2040                 struct thread_params *victim = NULL;
2041                 unsigned sub_size = 0;
2042
2043                 progress_lock();
2044                 for (;;) {
2045                         for (i = 0; !target && i < delta_search_threads; i++)
2046                                 if (!p[i].working)
2047                                         target = &p[i];
2048                         if (target)
2049                                 break;
2050                         pthread_cond_wait(&progress_cond, &progress_mutex);
2051                 }
2052
2053                 for (i = 0; i < delta_search_threads; i++)
2054                         if (p[i].remaining > 2*window &&
2055                             (!victim || victim->remaining < p[i].remaining))
2056                                 victim = &p[i];
2057                 if (victim) {
2058                         sub_size = victim->remaining / 2;
2059                         list = victim->list + victim->list_size - sub_size;
2060                         while (sub_size && list[0]->hash &&
2061                                list[0]->hash == list[-1]->hash) {
2062                                 list++;
2063                                 sub_size--;
2064                         }
2065                         if (!sub_size) {
2066                                 /*
2067                                  * It is possible for some "paths" to have
2068                                  * so many objects that no hash boundary
2069                                  * might be found.  Let's just steal the
2070                                  * exact half in that case.
2071                                  */
2072                                 sub_size = victim->remaining / 2;
2073                                 list -= sub_size;
2074                         }
2075                         target->list = list;
2076                         victim->list_size -= sub_size;
2077                         victim->remaining -= sub_size;
2078                 }
2079                 target->list_size = sub_size;
2080                 target->remaining = sub_size;
2081                 target->working = 1;
2082                 progress_unlock();
2083
2084                 pthread_mutex_lock(&target->mutex);
2085                 target->data_ready = 1;
2086                 pthread_cond_signal(&target->cond);
2087                 pthread_mutex_unlock(&target->mutex);
2088
2089                 if (!sub_size) {
2090                         pthread_join(target->thread, NULL);
2091                         pthread_cond_destroy(&target->cond);
2092                         pthread_mutex_destroy(&target->mutex);
2093                         active_threads--;
2094                 }
2095         }
2096         cleanup_threaded_search();
2097         free(p);
2098 }
2099
2100 #else
2101 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
2102 #endif
2103
2104 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
2105 {
2106         unsigned char peeled[20];
2107
2108         if (starts_with(path, "refs/tags/") && /* is a tag? */
2109             !peel_ref(path, peeled)        && /* peelable? */
2110             packlist_find(&to_pack, peeled, NULL))      /* object packed? */
2111                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
2112         return 0;
2113 }
2114
2115 static void prepare_pack(int window, int depth)
2116 {
2117         struct object_entry **delta_list;
2118         uint32_t i, nr_deltas;
2119         unsigned n;
2120
2121         get_object_details();
2122
2123         /*
2124          * If we're locally repacking then we need to be doubly careful
2125          * from now on in order to make sure no stealth corruption gets
2126          * propagated to the new pack.  Clients receiving streamed packs
2127          * should validate everything they get anyway so no need to incur
2128          * the additional cost here in that case.
2129          */
2130         if (!pack_to_stdout)
2131                 do_check_packed_object_crc = 1;
2132
2133         if (!to_pack.nr_objects || !window || !depth)
2134                 return;
2135
2136         delta_list = xmalloc(to_pack.nr_objects * sizeof(*delta_list));
2137         nr_deltas = n = 0;
2138
2139         for (i = 0; i < to_pack.nr_objects; i++) {
2140                 struct object_entry *entry = to_pack.objects + i;
2141
2142                 if (entry->delta)
2143                         /* This happens if we decided to reuse existing
2144                          * delta from a pack.  "reuse_delta &&" is implied.
2145                          */
2146                         continue;
2147
2148                 if (entry->size < 50)
2149                         continue;
2150
2151                 if (entry->no_try_delta)
2152                         continue;
2153
2154                 if (!entry->preferred_base) {
2155                         nr_deltas++;
2156                         if (entry->type < 0)
2157                                 die("unable to get type of object %s",
2158                                     sha1_to_hex(entry->idx.sha1));
2159                 } else {
2160                         if (entry->type < 0) {
2161                                 /*
2162                                  * This object is not found, but we
2163                                  * don't have to include it anyway.
2164                                  */
2165                                 continue;
2166                         }
2167                 }
2168
2169                 delta_list[n++] = entry;
2170         }
2171
2172         if (nr_deltas && n > 1) {
2173                 unsigned nr_done = 0;
2174                 if (progress)
2175                         progress_state = start_progress(_("Compressing objects"),
2176                                                         nr_deltas);
2177                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
2178                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
2179                 stop_progress(&progress_state);
2180                 if (nr_done != nr_deltas)
2181                         die("inconsistency with delta count");
2182         }
2183         free(delta_list);
2184 }
2185
2186 static int git_pack_config(const char *k, const char *v, void *cb)
2187 {
2188         if (!strcmp(k, "pack.window")) {
2189                 window = git_config_int(k, v);
2190                 return 0;
2191         }
2192         if (!strcmp(k, "pack.windowmemory")) {
2193                 window_memory_limit = git_config_ulong(k, v);
2194                 return 0;
2195         }
2196         if (!strcmp(k, "pack.depth")) {
2197                 depth = git_config_int(k, v);
2198                 return 0;
2199         }
2200         if (!strcmp(k, "pack.compression")) {
2201                 int level = git_config_int(k, v);
2202                 if (level == -1)
2203                         level = Z_DEFAULT_COMPRESSION;
2204                 else if (level < 0 || level > Z_BEST_COMPRESSION)
2205                         die("bad pack compression level %d", level);
2206                 pack_compression_level = level;
2207                 pack_compression_seen = 1;
2208                 return 0;
2209         }
2210         if (!strcmp(k, "pack.deltacachesize")) {
2211                 max_delta_cache_size = git_config_int(k, v);
2212                 return 0;
2213         }
2214         if (!strcmp(k, "pack.deltacachelimit")) {
2215                 cache_max_small_delta_size = git_config_int(k, v);
2216                 return 0;
2217         }
2218         if (!strcmp(k, "pack.writebitmaphashcache")) {
2219                 if (git_config_bool(k, v))
2220                         write_bitmap_options |= BITMAP_OPT_HASH_CACHE;
2221                 else
2222                         write_bitmap_options &= ~BITMAP_OPT_HASH_CACHE;
2223         }
2224         if (!strcmp(k, "pack.usebitmaps")) {
2225                 use_bitmap_index = git_config_bool(k, v);
2226                 return 0;
2227         }
2228         if (!strcmp(k, "pack.threads")) {
2229                 delta_search_threads = git_config_int(k, v);
2230                 if (delta_search_threads < 0)
2231                         die("invalid number of threads specified (%d)",
2232                             delta_search_threads);
2233 #ifdef NO_PTHREADS
2234                 if (delta_search_threads != 1)
2235                         warning("no threads support, ignoring %s", k);
2236 #endif
2237                 return 0;
2238         }
2239         if (!strcmp(k, "pack.indexversion")) {
2240                 pack_idx_opts.version = git_config_int(k, v);
2241                 if (pack_idx_opts.version > 2)
2242                         die("bad pack.indexversion=%"PRIu32,
2243                             pack_idx_opts.version);
2244                 return 0;
2245         }
2246         return git_default_config(k, v, cb);
2247 }
2248
2249 static void read_object_list_from_stdin(void)
2250 {
2251         char line[40 + 1 + PATH_MAX + 2];
2252         unsigned char sha1[20];
2253
2254         for (;;) {
2255                 if (!fgets(line, sizeof(line), stdin)) {
2256                         if (feof(stdin))
2257                                 break;
2258                         if (!ferror(stdin))
2259                                 die("fgets returned NULL, not EOF, not error!");
2260                         if (errno != EINTR)
2261                                 die_errno("fgets");
2262                         clearerr(stdin);
2263                         continue;
2264                 }
2265                 if (line[0] == '-') {
2266                         if (get_sha1_hex(line+1, sha1))
2267                                 die("expected edge sha1, got garbage:\n %s",
2268                                     line);
2269                         add_preferred_base(sha1);
2270                         continue;
2271                 }
2272                 if (get_sha1_hex(line, sha1))
2273                         die("expected sha1, got garbage:\n %s", line);
2274
2275                 add_preferred_base_object(line+41);
2276                 add_object_entry(sha1, 0, line+41, 0);
2277         }
2278 }
2279
2280 #define OBJECT_ADDED (1u<<20)
2281
2282 static void show_commit(struct commit *commit, void *data)
2283 {
2284         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
2285         commit->object.flags |= OBJECT_ADDED;
2286
2287         if (write_bitmap_index)
2288                 index_commit_for_bitmap(commit);
2289 }
2290
2291 static void show_object(struct object *obj,
2292                         const struct name_path *path, const char *last,
2293                         void *data)
2294 {
2295         char *name = path_name(path, last);
2296
2297         add_preferred_base_object(name);
2298         add_object_entry(obj->sha1, obj->type, name, 0);
2299         obj->flags |= OBJECT_ADDED;
2300
2301         /*
2302          * We will have generated the hash from the name,
2303          * but not saved a pointer to it - we can free it
2304          */
2305         free((char *)name);
2306 }
2307
2308 static void show_edge(struct commit *commit)
2309 {
2310         add_preferred_base(commit->object.sha1);
2311 }
2312
2313 struct in_pack_object {
2314         off_t offset;
2315         struct object *object;
2316 };
2317
2318 struct in_pack {
2319         int alloc;
2320         int nr;
2321         struct in_pack_object *array;
2322 };
2323
2324 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
2325 {
2326         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
2327         in_pack->array[in_pack->nr].object = object;
2328         in_pack->nr++;
2329 }
2330
2331 /*
2332  * Compare the objects in the offset order, in order to emulate the
2333  * "git rev-list --objects" output that produced the pack originally.
2334  */
2335 static int ofscmp(const void *a_, const void *b_)
2336 {
2337         struct in_pack_object *a = (struct in_pack_object *)a_;
2338         struct in_pack_object *b = (struct in_pack_object *)b_;
2339
2340         if (a->offset < b->offset)
2341                 return -1;
2342         else if (a->offset > b->offset)
2343                 return 1;
2344         else
2345                 return hashcmp(a->object->sha1, b->object->sha1);
2346 }
2347
2348 static void add_objects_in_unpacked_packs(struct rev_info *revs)
2349 {
2350         struct packed_git *p;
2351         struct in_pack in_pack;
2352         uint32_t i;
2353
2354         memset(&in_pack, 0, sizeof(in_pack));
2355
2356         for (p = packed_git; p; p = p->next) {
2357                 const unsigned char *sha1;
2358                 struct object *o;
2359
2360                 if (!p->pack_local || p->pack_keep)
2361                         continue;
2362                 if (open_pack_index(p))
2363                         die("cannot open pack index");
2364
2365                 ALLOC_GROW(in_pack.array,
2366                            in_pack.nr + p->num_objects,
2367                            in_pack.alloc);
2368
2369                 for (i = 0; i < p->num_objects; i++) {
2370                         sha1 = nth_packed_object_sha1(p, i);
2371                         o = lookup_unknown_object(sha1);
2372                         if (!(o->flags & OBJECT_ADDED))
2373                                 mark_in_pack_object(o, p, &in_pack);
2374                         o->flags |= OBJECT_ADDED;
2375                 }
2376         }
2377
2378         if (in_pack.nr) {
2379                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
2380                       ofscmp);
2381                 for (i = 0; i < in_pack.nr; i++) {
2382                         struct object *o = in_pack.array[i].object;
2383                         add_object_entry(o->sha1, o->type, "", 0);
2384                 }
2385         }
2386         free(in_pack.array);
2387 }
2388
2389 static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2390 {
2391         static struct packed_git *last_found = (void *)1;
2392         struct packed_git *p;
2393
2394         p = (last_found != (void *)1) ? last_found : packed_git;
2395
2396         while (p) {
2397                 if ((!p->pack_local || p->pack_keep) &&
2398                         find_pack_entry_one(sha1, p)) {
2399                         last_found = p;
2400                         return 1;
2401                 }
2402                 if (p == last_found)
2403                         p = packed_git;
2404                 else
2405                         p = p->next;
2406                 if (p == last_found)
2407                         p = p->next;
2408         }
2409         return 0;
2410 }
2411
2412 /*
2413  * Store a list of sha1s that are should not be discarded
2414  * because they are either written too recently, or are
2415  * reachable from another object that was.
2416  *
2417  * This is filled by get_object_list.
2418  */
2419 static struct sha1_array recent_objects;
2420
2421 static int loosened_object_can_be_discarded(const unsigned char *sha1,
2422                                             unsigned long mtime)
2423 {
2424         if (!unpack_unreachable_expiration)
2425                 return 0;
2426         if (mtime > unpack_unreachable_expiration)
2427                 return 0;
2428         if (sha1_array_lookup(&recent_objects, sha1) >= 0)
2429                 return 0;
2430         return 1;
2431 }
2432
2433 static void loosen_unused_packed_objects(struct rev_info *revs)
2434 {
2435         struct packed_git *p;
2436         uint32_t i;
2437         const unsigned char *sha1;
2438
2439         for (p = packed_git; p; p = p->next) {
2440                 if (!p->pack_local || p->pack_keep)
2441                         continue;
2442
2443                 if (open_pack_index(p))
2444                         die("cannot open pack index");
2445
2446                 for (i = 0; i < p->num_objects; i++) {
2447                         sha1 = nth_packed_object_sha1(p, i);
2448                         if (!packlist_find(&to_pack, sha1, NULL) &&
2449                             !has_sha1_pack_kept_or_nonlocal(sha1) &&
2450                             !loosened_object_can_be_discarded(sha1, p->mtime))
2451                                 if (force_object_loose(sha1, p->mtime))
2452                                         die("unable to force loose object");
2453                 }
2454         }
2455 }
2456
2457 /*
2458  * This tracks any options which a reader of the pack might
2459  * not understand, and which would therefore prevent blind reuse
2460  * of what we have on disk.
2461  */
2462 static int pack_options_allow_reuse(void)
2463 {
2464         return allow_ofs_delta;
2465 }
2466
2467 static int get_object_list_from_bitmap(struct rev_info *revs)
2468 {
2469         if (prepare_bitmap_walk(revs) < 0)
2470                 return -1;
2471
2472         if (pack_options_allow_reuse() &&
2473             !reuse_partial_packfile_from_bitmap(
2474                         &reuse_packfile,
2475                         &reuse_packfile_objects,
2476                         &reuse_packfile_offset)) {
2477                 assert(reuse_packfile_objects);
2478                 nr_result += reuse_packfile_objects;
2479                 display_progress(progress_state, nr_result);
2480         }
2481
2482         traverse_bitmap_commit_list(&add_object_entry_from_bitmap);
2483         return 0;
2484 }
2485
2486 static void record_recent_object(struct object *obj,
2487                                  const struct name_path *path,
2488                                  const char *last,
2489                                  void *data)
2490 {
2491         sha1_array_append(&recent_objects, obj->sha1);
2492 }
2493
2494 static void record_recent_commit(struct commit *commit, void *data)
2495 {
2496         sha1_array_append(&recent_objects, commit->object.sha1);
2497 }
2498
2499 static void get_object_list(int ac, const char **av)
2500 {
2501         struct rev_info revs;
2502         char line[1000];
2503         int flags = 0;
2504
2505         init_revisions(&revs, NULL);
2506         save_commit_buffer = 0;
2507         setup_revisions(ac, av, &revs, NULL);
2508
2509         /* make sure shallows are read */
2510         is_repository_shallow();
2511
2512         while (fgets(line, sizeof(line), stdin) != NULL) {
2513                 int len = strlen(line);
2514                 if (len && line[len - 1] == '\n')
2515                         line[--len] = 0;
2516                 if (!len)
2517                         break;
2518                 if (*line == '-') {
2519                         if (!strcmp(line, "--not")) {
2520                                 flags ^= UNINTERESTING;
2521                                 write_bitmap_index = 0;
2522                                 continue;
2523                         }
2524                         if (starts_with(line, "--shallow ")) {
2525                                 unsigned char sha1[20];
2526                                 if (get_sha1_hex(line + 10, sha1))
2527                                         die("not an SHA-1 '%s'", line + 10);
2528                                 register_shallow(sha1);
2529                                 use_bitmap_index = 0;
2530                                 continue;
2531                         }
2532                         die("not a rev '%s'", line);
2533                 }
2534                 if (handle_revision_arg(line, &revs, flags, REVARG_CANNOT_BE_FILENAME))
2535                         die("bad revision '%s'", line);
2536         }
2537
2538         if (use_bitmap_index && !get_object_list_from_bitmap(&revs))
2539                 return;
2540
2541         if (prepare_revision_walk(&revs))
2542                 die("revision walk setup failed");
2543         mark_edges_uninteresting(&revs, show_edge);
2544         traverse_commit_list(&revs, show_commit, show_object, NULL);
2545
2546         if (unpack_unreachable_expiration) {
2547                 revs.ignore_missing_links = 1;
2548                 if (add_unseen_recent_objects_to_traversal(&revs,
2549                                 unpack_unreachable_expiration))
2550                         die("unable to add recent objects");
2551                 if (prepare_revision_walk(&revs))
2552                         die("revision walk setup failed");
2553                 traverse_commit_list(&revs, record_recent_commit,
2554                                      record_recent_object, NULL);
2555         }
2556
2557         if (keep_unreachable)
2558                 add_objects_in_unpacked_packs(&revs);
2559         if (unpack_unreachable)
2560                 loosen_unused_packed_objects(&revs);
2561
2562         sha1_array_clear(&recent_objects);
2563 }
2564
2565 static int option_parse_index_version(const struct option *opt,
2566                                       const char *arg, int unset)
2567 {
2568         char *c;
2569         const char *val = arg;
2570         pack_idx_opts.version = strtoul(val, &c, 10);
2571         if (pack_idx_opts.version > 2)
2572                 die(_("unsupported index version %s"), val);
2573         if (*c == ',' && c[1])
2574                 pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
2575         if (*c || pack_idx_opts.off32_limit & 0x80000000)
2576                 die(_("bad index version '%s'"), val);
2577         return 0;
2578 }
2579
2580 static int option_parse_unpack_unreachable(const struct option *opt,
2581                                            const char *arg, int unset)
2582 {
2583         if (unset) {
2584                 unpack_unreachable = 0;
2585                 unpack_unreachable_expiration = 0;
2586         }
2587         else {
2588                 unpack_unreachable = 1;
2589                 if (arg)
2590                         unpack_unreachable_expiration = approxidate(arg);
2591         }
2592         return 0;
2593 }
2594
2595 static int option_parse_ulong(const struct option *opt,
2596                               const char *arg, int unset)
2597 {
2598         if (unset)
2599                 die(_("option %s does not accept negative form"),
2600                     opt->long_name);
2601
2602         if (!git_parse_ulong(arg, opt->value))
2603                 die(_("unable to parse value '%s' for option %s"),
2604                     arg, opt->long_name);
2605         return 0;
2606 }
2607
2608 #define OPT_ULONG(s, l, v, h) \
2609         { OPTION_CALLBACK, (s), (l), (v), "n", (h),     \
2610           PARSE_OPT_NONEG, option_parse_ulong }
2611
2612 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2613 {
2614         int use_internal_rev_list = 0;
2615         int thin = 0;
2616         int all_progress_implied = 0;
2617         struct argv_array rp = ARGV_ARRAY_INIT;
2618         int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
2619         int rev_list_index = 0;
2620         struct option pack_objects_options[] = {
2621                 OPT_SET_INT('q', "quiet", &progress,
2622                             N_("do not show progress meter"), 0),
2623                 OPT_SET_INT(0, "progress", &progress,
2624                             N_("show progress meter"), 1),
2625                 OPT_SET_INT(0, "all-progress", &progress,
2626                             N_("show progress meter during object writing phase"), 2),
2627                 OPT_BOOL(0, "all-progress-implied",
2628                          &all_progress_implied,
2629                          N_("similar to --all-progress when progress meter is shown")),
2630                 { OPTION_CALLBACK, 0, "index-version", NULL, N_("version[,offset]"),
2631                   N_("write the pack index file in the specified idx format version"),
2632                   0, option_parse_index_version },
2633                 OPT_ULONG(0, "max-pack-size", &pack_size_limit,
2634                           N_("maximum size of each output pack file")),
2635                 OPT_BOOL(0, "local", &local,
2636                          N_("ignore borrowed objects from alternate object store")),
2637                 OPT_BOOL(0, "incremental", &incremental,
2638                          N_("ignore packed objects")),
2639                 OPT_INTEGER(0, "window", &window,
2640                             N_("limit pack window by objects")),
2641                 OPT_ULONG(0, "window-memory", &window_memory_limit,
2642                           N_("limit pack window by memory in addition to object limit")),
2643                 OPT_INTEGER(0, "depth", &depth,
2644                             N_("maximum length of delta chain allowed in the resulting pack")),
2645                 OPT_BOOL(0, "reuse-delta", &reuse_delta,
2646                          N_("reuse existing deltas")),
2647                 OPT_BOOL(0, "reuse-object", &reuse_object,
2648                          N_("reuse existing objects")),
2649                 OPT_BOOL(0, "delta-base-offset", &allow_ofs_delta,
2650                          N_("use OFS_DELTA objects")),
2651                 OPT_INTEGER(0, "threads", &delta_search_threads,
2652                             N_("use threads when searching for best delta matches")),
2653                 OPT_BOOL(0, "non-empty", &non_empty,
2654                          N_("do not create an empty pack output")),
2655                 OPT_BOOL(0, "revs", &use_internal_rev_list,
2656                          N_("read revision arguments from standard input")),
2657                 { OPTION_SET_INT, 0, "unpacked", &rev_list_unpacked, NULL,
2658                   N_("limit the objects to those that are not yet packed"),
2659                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2660                 { OPTION_SET_INT, 0, "all", &rev_list_all, NULL,
2661                   N_("include objects reachable from any reference"),
2662                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2663                 { OPTION_SET_INT, 0, "reflog", &rev_list_reflog, NULL,
2664                   N_("include objects referred by reflog entries"),
2665                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2666                 { OPTION_SET_INT, 0, "indexed-objects", &rev_list_index, NULL,
2667                   N_("include objects referred to by the index"),
2668                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2669                 OPT_BOOL(0, "stdout", &pack_to_stdout,
2670                          N_("output pack to stdout")),
2671                 OPT_BOOL(0, "include-tag", &include_tag,
2672                          N_("include tag objects that refer to objects to be packed")),
2673                 OPT_BOOL(0, "keep-unreachable", &keep_unreachable,
2674                          N_("keep unreachable objects")),
2675                 { OPTION_CALLBACK, 0, "unpack-unreachable", NULL, N_("time"),
2676                   N_("unpack unreachable objects newer than <time>"),
2677                   PARSE_OPT_OPTARG, option_parse_unpack_unreachable },
2678                 OPT_BOOL(0, "thin", &thin,
2679                          N_("create thin packs")),
2680                 OPT_BOOL(0, "honor-pack-keep", &ignore_packed_keep,
2681                          N_("ignore packs that have companion .keep file")),
2682                 OPT_INTEGER(0, "compression", &pack_compression_level,
2683                             N_("pack compression level")),
2684                 OPT_SET_INT(0, "keep-true-parents", &grafts_replace_parents,
2685                             N_("do not hide commits by grafts"), 0),
2686                 OPT_BOOL(0, "use-bitmap-index", &use_bitmap_index,
2687                          N_("use a bitmap index if available to speed up counting objects")),
2688                 OPT_BOOL(0, "write-bitmap-index", &write_bitmap_index,
2689                          N_("write a bitmap index together with the pack index")),
2690                 OPT_END(),
2691         };
2692
2693         check_replace_refs = 0;
2694
2695         reset_pack_idx_option(&pack_idx_opts);
2696         git_config(git_pack_config, NULL);
2697         if (!pack_compression_seen && core_compression_seen)
2698                 pack_compression_level = core_compression_level;
2699
2700         progress = isatty(2);
2701         argc = parse_options(argc, argv, prefix, pack_objects_options,
2702                              pack_usage, 0);
2703
2704         if (argc) {
2705                 base_name = argv[0];
2706                 argc--;
2707         }
2708         if (pack_to_stdout != !base_name || argc)
2709                 usage_with_options(pack_usage, pack_objects_options);
2710
2711         argv_array_push(&rp, "pack-objects");
2712         if (thin) {
2713                 use_internal_rev_list = 1;
2714                 argv_array_push(&rp, "--objects-edge");
2715         } else
2716                 argv_array_push(&rp, "--objects");
2717
2718         if (rev_list_all) {
2719                 use_internal_rev_list = 1;
2720                 argv_array_push(&rp, "--all");
2721         }
2722         if (rev_list_reflog) {
2723                 use_internal_rev_list = 1;
2724                 argv_array_push(&rp, "--reflog");
2725         }
2726         if (rev_list_index) {
2727                 use_internal_rev_list = 1;
2728                 argv_array_push(&rp, "--indexed-objects");
2729         }
2730         if (rev_list_unpacked) {
2731                 use_internal_rev_list = 1;
2732                 argv_array_push(&rp, "--unpacked");
2733         }
2734
2735         if (!reuse_object)
2736                 reuse_delta = 0;
2737         if (pack_compression_level == -1)
2738                 pack_compression_level = Z_DEFAULT_COMPRESSION;
2739         else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
2740                 die("bad pack compression level %d", pack_compression_level);
2741
2742         if (!delta_search_threads)      /* --threads=0 means autodetect */
2743                 delta_search_threads = online_cpus();
2744
2745 #ifdef NO_PTHREADS
2746         if (delta_search_threads != 1)
2747                 warning("no threads support, ignoring --threads");
2748 #endif
2749         if (!pack_to_stdout && !pack_size_limit)
2750                 pack_size_limit = pack_size_limit_cfg;
2751         if (pack_to_stdout && pack_size_limit)
2752                 die("--max-pack-size cannot be used to build a pack for transfer.");
2753         if (pack_size_limit && pack_size_limit < 1024*1024) {
2754                 warning("minimum pack size limit is 1 MiB");
2755                 pack_size_limit = 1024*1024;
2756         }
2757
2758         if (!pack_to_stdout && thin)
2759                 die("--thin cannot be used to build an indexable pack.");
2760
2761         if (keep_unreachable && unpack_unreachable)
2762                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2763         if (!rev_list_all || !rev_list_reflog || !rev_list_index)
2764                 unpack_unreachable_expiration = 0;
2765
2766         if (!use_internal_rev_list || !pack_to_stdout || is_repository_shallow())
2767                 use_bitmap_index = 0;
2768
2769         if (pack_to_stdout || !rev_list_all)
2770                 write_bitmap_index = 0;
2771
2772         if (progress && all_progress_implied)
2773                 progress = 2;
2774
2775         prepare_packed_git();
2776
2777         if (progress)
2778                 progress_state = start_progress(_("Counting objects"), 0);
2779         if (!use_internal_rev_list)
2780                 read_object_list_from_stdin();
2781         else {
2782                 get_object_list(rp.argc, rp.argv);
2783                 argv_array_clear(&rp);
2784         }
2785         cleanup_preferred_base();
2786         if (include_tag && nr_result)
2787                 for_each_ref(add_ref_tag, NULL);
2788         stop_progress(&progress_state);
2789
2790         if (non_empty && !nr_result)
2791                 return 0;
2792         if (nr_result)
2793                 prepare_pack(window, depth);
2794         write_pack_file();
2795         if (progress)
2796                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2797                         " reused %"PRIu32" (delta %"PRIu32")\n",
2798                         written, written_delta, reused, reused_delta);
2799         return 0;
2800 }