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