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 "progress.h"
  18 #include "refs.h"
  19
  20 #ifdef THREADED_DELTA_SEARCH
  21 #include "thread-utils.h"
  22 #include <pthread.h>
  23 #endif
  24
  25 static const char pack_usage[] = "\
  26 git-pack-objects [{ -q | --progress | --all-progress }] \n\
  27         [--max-pack-size=N] [--local] [--incremental] \n\
  28         [--window=N] [--window-memory=N] [--depth=N] \n\
  29         [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
  30         [--threads=N] [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
  31         [--stdout | base-name] [--include-tag] [--keep-unreachable] \n\
  32         [<ref-list | <object-list]";
  33
  34 struct object_entry {
  35         struct pack_idx_entry idx;
  36         unsigned long size;     /* uncompressed size */
  37         struct packed_git *in_pack;     /* already in pack */
  38         off_t in_pack_offset;
  39         struct object_entry *delta;     /* delta base object */
  40         struct object_entry *delta_child; /* deltified objects who bases me */
  41         struct object_entry *delta_sibling; /* other deltified objects who
  42                                              * uses the same base as me
  43                                              */
  44         void *delta_data;       /* cached delta (uncompressed) */
  45         unsigned long delta_size;       /* delta data size (uncompressed) */
  46         unsigned int hash;      /* name hint hash */
  47         enum object_type type;
  48         enum object_type in_pack_type;  /* could be delta */
  49         unsigned char in_pack_header_size;
  50         unsigned char preferred_base; /* we do not pack this, but is available
  51                                        * to be used as the base object to delta
  52                                        * objects against.
  53                                        */
  54         unsigned char no_try_delta;
  55 };
  56
  57 /*
  58  * Objects we are going to pack are collected in objects array (dynamically
  59  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  60  * in the order we see -- typically rev-list --objects order that gives us
  61  * nice "minimum seek" order.
  62  */
  63 static struct object_entry *objects;
  64 static struct pack_idx_entry **written_list;
  65 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
  66
  67 static int non_empty;
  68 static int no_reuse_delta, no_reuse_object, keep_unreachable, include_tag;
  69 static int local;
  70 static int incremental;
  71 static int allow_ofs_delta;
  72 static const char *base_name;
  73 static int progress = 1;
  74 static int window = 10;
  75 static uint32_t pack_size_limit, pack_size_limit_cfg;
  76 static int depth = 50;
  77 static int delta_search_threads = 1;
  78 static int pack_to_stdout;
  79 static int num_preferred_base;
  80 static struct progress *progress_state;
  81 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  82 static int pack_compression_seen;
  83
  84 static unsigned long delta_cache_size = 0;
  85 static unsigned long max_delta_cache_size = 0;
  86 static unsigned long cache_max_small_delta_size = 1000;
  87
  88 static unsigned long window_memory_limit = 0;
  89
  90 /*
  91  * The object names in objects array are hashed with this hashtable,
  92  * to help looking up the entry by object name.
  93  * This hashtable is built after all the objects are seen.
  94  */
  95 static int *object_ix;
  96 static int object_ix_hashsz;
  97
  98 /*
  99  * stats
 100  */
 101 static uint32_t written, written_delta;
 102 static uint32_t reused, reused_delta;
 103
 104
 105 static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
 106 {
 107         unsigned long othersize, delta_size;
 108         enum object_type type;
 109         void *otherbuf = read_sha1_file(entry->delta->idx.sha1, &type, &othersize);
 110         void *delta_buf;
 111
 112         if (!otherbuf)
 113                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 114         delta_buf = diff_delta(otherbuf, othersize,
 115                                buf, size, &delta_size, 0);
 116         if (!delta_buf || delta_size != entry->delta_size)
 117                 die("delta size changed");
 118         free(buf);
 119         free(otherbuf);
 120         return delta_buf;
 121 }
 122
 123 /*
 124  * The per-object header is a pretty dense thing, which is
 125  *  - first byte: low four bits are "size", then three bits of "type",
 126  *    and the high bit is "size continues".
 127  *  - each byte afterwards: low seven bits are size continuation,
 128  *    with the high bit being "size continues"
 129  */
 130 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 131 {
 132         int n = 1;
 133         unsigned char c;
 134
 135         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 136                 die("bad type %d", type);
 137
 138         c = (type << 4) | (size & 15);
 139         size >>= 4;
 140         while (size) {
 141                 *hdr++ = c | 0x80;
 142                 c = size & 0x7f;
 143                 size >>= 7;
 144                 n++;
 145         }
 146         *hdr = c;
 147         return n;
 148 }
 149
 150 /*
 151  * we are going to reuse the existing object data as is.  make
 152  * sure it is not corrupt.
 153  */
 154 static int check_pack_inflate(struct packed_git *p,
 155                 struct pack_window **w_curs,
 156                 off_t offset,
 157                 off_t len,
 158                 unsigned long expect)
 159 {
 160         z_stream stream;
 161         unsigned char fakebuf[4096], *in;
 162         int st;
 163
 164         memset(&stream, 0, sizeof(stream));
 165         inflateInit(&stream);
 166         do {
 167                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 168                 stream.next_in = in;
 169                 stream.next_out = fakebuf;
 170                 stream.avail_out = sizeof(fakebuf);
 171                 st = inflate(&stream, Z_FINISH);
 172                 offset += stream.next_in - in;
 173         } while (st == Z_OK || st == Z_BUF_ERROR);
 174         inflateEnd(&stream);
 175         return (st == Z_STREAM_END &&
 176                 stream.total_out == expect &&
 177                 stream.total_in == len) ? 0 : -1;
 178 }
 179
 180 static int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
 181                           off_t offset, off_t len, unsigned int nr)
 182 {
 183         const uint32_t *index_crc;
 184         uint32_t data_crc = crc32(0, Z_NULL, 0);
 185
 186         do {
 187                 unsigned int avail;
 188                 void *data = use_pack(p, w_curs, offset, &avail);
 189                 if (avail > len)
 190                         avail = len;
 191                 data_crc = crc32(data_crc, data, avail);
 192                 offset += avail;
 193                 len -= avail;
 194         } while (len);
 195
 196         index_crc = p->index_data;
 197         index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
 198
 199         return data_crc != ntohl(*index_crc);
 200 }
 201
 202 static void copy_pack_data(struct sha1file *f,
 203                 struct packed_git *p,
 204                 struct pack_window **w_curs,
 205                 off_t offset,
 206                 off_t len)
 207 {
 208         unsigned char *in;
 209         unsigned int avail;
 210
 211         while (len) {
 212                 in = use_pack(p, w_curs, offset, &avail);
 213                 if (avail > len)
 214                         avail = (unsigned int)len;
 215                 sha1write(f, in, avail);
 216                 offset += avail;
 217                 len -= avail;
 218         }
 219 }
 220
 221 static unsigned long write_object(struct sha1file *f,
 222                                   struct object_entry *entry,
 223                                   off_t write_offset)
 224 {
 225         unsigned long size;
 226         enum object_type type;
 227         void *buf;
 228         unsigned char header[10];
 229         unsigned char dheader[10];
 230         unsigned hdrlen;
 231         off_t datalen;
 232         enum object_type obj_type;
 233         int to_reuse = 0;
 234         /* write limit if limited packsize and not first object */
 235         unsigned long limit = pack_size_limit && nr_written ?
 236                                 pack_size_limit - write_offset : 0;
 237                                 /* no if no delta */
 238         int usable_delta =      !entry->delta ? 0 :
 239                                 /* yes if unlimited packfile */
 240                                 !pack_size_limit ? 1 :
 241                                 /* no if base written to previous pack */
 242                                 entry->delta->idx.offset == (off_t)-1 ? 0 :
 243                                 /* otherwise double-check written to this
 244                                  * pack,  like we do below
 245                                  */
 246                                 entry->delta->idx.offset ? 1 : 0;
 247
 248         if (!pack_to_stdout)
 249                 crc32_begin(f);
 250
 251         obj_type = entry->type;
 252         if (no_reuse_object)
 253                 to_reuse = 0;   /* explicit */
 254         else if (!entry->in_pack)
 255                 to_reuse = 0;   /* can't reuse what we don't have */
 256         else if (obj_type == OBJ_REF_DELTA || obj_type == OBJ_OFS_DELTA)
 257                                 /* check_object() decided it for us ... */
 258                 to_reuse = usable_delta;
 259                                 /* ... but pack split may override that */
 260         else if (obj_type != entry->in_pack_type)
 261                 to_reuse = 0;   /* pack has delta which is unusable */
 262         else if (entry->delta)
 263                 to_reuse = 0;   /* we want to pack afresh */
 264         else
 265                 to_reuse = 1;   /* we have it in-pack undeltified,
 266                                  * and we do not need to deltify it.
 267                                  */
 268
 269         if (!to_reuse) {
 270                 z_stream stream;
 271                 unsigned long maxsize;
 272                 void *out;
 273                 if (!usable_delta) {
 274                         buf = read_sha1_file(entry->idx.sha1, &obj_type, &size);
 275                         if (!buf)
 276                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 277                 } else if (entry->delta_data) {
 278                         size = entry->delta_size;
 279                         buf = entry->delta_data;
 280                         entry->delta_data = NULL;
 281                         obj_type = (allow_ofs_delta && entry->delta->idx.offset) ?
 282                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 283                 } else {
 284                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 285                         if (!buf)
 286                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 287                         buf = delta_against(buf, size, entry);
 288                         size = entry->delta_size;
 289                         obj_type = (allow_ofs_delta && entry->delta->idx.offset) ?
 290                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 291                 }
 292                 /* compress the data to store and put compressed length in datalen */
 293                 memset(&stream, 0, sizeof(stream));
 294                 deflateInit(&stream, pack_compression_level);
 295                 maxsize = deflateBound(&stream, size);
 296                 out = xmalloc(maxsize);
 297                 /* Compress it */
 298                 stream.next_in = buf;
 299                 stream.avail_in = size;
 300                 stream.next_out = out;
 301                 stream.avail_out = maxsize;
 302                 while (deflate(&stream, Z_FINISH) == Z_OK)
 303                         /* nothing */;
 304                 deflateEnd(&stream);
 305                 datalen = stream.total_out;
 306
 307                 /*
 308                  * The object header is a byte of 'type' followed by zero or
 309                  * more bytes of length.
 310                  */
 311                 hdrlen = encode_header(obj_type, size, header);
 312
 313                 if (obj_type == OBJ_OFS_DELTA) {
 314                         /*
 315                          * Deltas with relative base contain an additional
 316                          * encoding of the relative offset for the delta
 317                          * base from this object's position in the pack.
 318                          */
 319                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 320                         unsigned pos = sizeof(dheader) - 1;
 321                         dheader[pos] = ofs & 127;
 322                         while (ofs >>= 7)
 323                                 dheader[--pos] = 128 | (--ofs & 127);
 324                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 325                                 free(out);
 326                                 free(buf);
 327                                 return 0;
 328                         }
 329                         sha1write(f, header, hdrlen);
 330                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 331                         hdrlen += sizeof(dheader) - pos;
 332                 } else if (obj_type == OBJ_REF_DELTA) {
 333                         /*
 334                          * Deltas with a base reference contain
 335                          * an additional 20 bytes for the base sha1.
 336                          */
 337                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 338                                 free(out);
 339                                 free(buf);
 340                                 return 0;
 341                         }
 342                         sha1write(f, header, hdrlen);
 343                         sha1write(f, entry->delta->idx.sha1, 20);
 344                         hdrlen += 20;
 345                 } else {
 346                         if (limit && hdrlen + datalen + 20 >= limit) {
 347                                 free(out);
 348                                 free(buf);
 349                                 return 0;
 350                         }
 351                         sha1write(f, header, hdrlen);
 352                 }
 353                 sha1write(f, out, datalen);
 354                 free(out);
 355                 free(buf);
 356         }
 357         else {
 358                 struct packed_git *p = entry->in_pack;
 359                 struct pack_window *w_curs = NULL;
 360                 struct revindex_entry *revidx;
 361                 off_t offset;
 362
 363                 if (entry->delta) {
 364                         obj_type = (allow_ofs_delta && entry->delta->idx.offset) ?
 365                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 366                         reused_delta++;
 367                 }
 368                 hdrlen = encode_header(obj_type, entry->size, header);
 369                 offset = entry->in_pack_offset;
 370                 revidx = find_pack_revindex(p, offset);
 371                 datalen = revidx[1].offset - offset;
 372                 if (!pack_to_stdout && p->index_version > 1 &&
 373                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
 374                         die("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 375                 offset += entry->in_pack_header_size;
 376                 datalen -= entry->in_pack_header_size;
 377                 if (obj_type == OBJ_OFS_DELTA) {
 378                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 379                         unsigned pos = sizeof(dheader) - 1;
 380                         dheader[pos] = ofs & 127;
 381                         while (ofs >>= 7)
 382                                 dheader[--pos] = 128 | (--ofs & 127);
 383                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit)
 384                                 return 0;
 385                         sha1write(f, header, hdrlen);
 386                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 387                         hdrlen += sizeof(dheader) - pos;
 388                 } else if (obj_type == OBJ_REF_DELTA) {
 389                         if (limit && hdrlen + 20 + datalen + 20 >= limit)
 390                                 return 0;
 391                         sha1write(f, header, hdrlen);
 392                         sha1write(f, entry->delta->idx.sha1, 20);
 393                         hdrlen += 20;
 394                 } else {
 395                         if (limit && hdrlen + datalen + 20 >= limit)
 396                                 return 0;
 397                         sha1write(f, header, hdrlen);
 398                 }
 399
 400                 if (!pack_to_stdout && p->index_version == 1 &&
 401                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
 402                         die("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 403                 copy_pack_data(f, p, &w_curs, offset, datalen);
 404                 unuse_pack(&w_curs);
 405                 reused++;
 406         }
 407         if (usable_delta)
 408                 written_delta++;
 409         written++;
 410         if (!pack_to_stdout)
 411                 entry->idx.crc32 = crc32_end(f);
 412         return hdrlen + datalen;
 413 }
 414
 415 static off_t write_one(struct sha1file *f,
 416                                struct object_entry *e,
 417                                off_t offset)
 418 {
 419         unsigned long size;
 420
 421         /* offset is non zero if object is written already. */
 422         if (e->idx.offset || e->preferred_base)
 423                 return offset;
 424
 425         /* if we are deltified, write out base object first. */
 426         if (e->delta) {
 427                 offset = write_one(f, e->delta, offset);
 428                 if (!offset)
 429                         return 0;
 430         }
 431
 432         e->idx.offset = offset;
 433         size = write_object(f, e, offset);
 434         if (!size) {
 435                 e->idx.offset = 0;
 436                 return 0;
 437         }
 438         written_list[nr_written++] = &e->idx;
 439
 440         /* make sure off_t is sufficiently large not to wrap */
 441         if (offset > offset + size)
 442                 die("pack too large for current definition of off_t");
 443         return offset + size;
 444 }
 445
 446 /* forward declaration for write_pack_file */
 447 static int adjust_perm(const char *path, mode_t mode);
 448
 449 static void write_pack_file(void)
 450 {
 451         uint32_t i = 0, j;
 452         struct sha1file *f;
 453         off_t offset, offset_one, last_obj_offset = 0;
 454         struct pack_header hdr;
 455         int do_progress = progress >> pack_to_stdout;
 456         uint32_t nr_remaining = nr_result;
 457
 458         if (do_progress)
 459                 progress_state = start_progress("Writing objects", nr_result);
 460         written_list = xmalloc(nr_objects * sizeof(*written_list));
 461
 462         do {
 463                 unsigned char sha1[20];
 464                 char *pack_tmp_name = NULL;
 465
 466                 if (pack_to_stdout) {
 467                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 468                 } else {
 469                         char tmpname[PATH_MAX];
 470                         int fd;
 471                         snprintf(tmpname, sizeof(tmpname),
 472                                  "%s/tmp_pack_XXXXXX", get_object_directory());
 473                         fd = xmkstemp(tmpname);
 474                         pack_tmp_name = xstrdup(tmpname);
 475                         f = sha1fd(fd, pack_tmp_name);
 476                 }
 477
 478                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
 479                 hdr.hdr_version = htonl(PACK_VERSION);
 480                 hdr.hdr_entries = htonl(nr_remaining);
 481                 sha1write(f, &hdr, sizeof(hdr));
 482                 offset = sizeof(hdr);
 483                 nr_written = 0;
 484                 for (; i < nr_objects; i++) {
 485                         last_obj_offset = offset;
 486                         offset_one = write_one(f, objects + i, offset);
 487                         if (!offset_one)
 488                                 break;
 489                         offset = offset_one;
 490                         display_progress(progress_state, written);
 491                 }
 492
 493                 /*
 494                  * Did we write the wrong # entries in the header?
 495                  * If so, rewrite it like in fast-import
 496                  */
 497                 if (pack_to_stdout || nr_written == nr_remaining) {
 498                         sha1close(f, sha1, 1);
 499                 } else {
 500                         int fd = sha1close(f, NULL, 0);
 501                         fixup_pack_header_footer(fd, sha1, pack_tmp_name, nr_written);
 502                         close(fd);
 503                 }
 504
 505                 if (!pack_to_stdout) {
 506                         mode_t mode = umask(0);
 507                         char *idx_tmp_name, tmpname[PATH_MAX];
 508
 509                         umask(mode);
 510                         mode = 0444 & ~mode;
 511
 512                         idx_tmp_name = write_idx_file(NULL, written_list,
 513                                                       nr_written, sha1);
 514                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 515                                  base_name, sha1_to_hex(sha1));
 516                         if (adjust_perm(pack_tmp_name, mode))
 517                                 die("unable to make temporary pack file readable: %s",
 518                                     strerror(errno));
 519                         if (rename(pack_tmp_name, tmpname))
 520                                 die("unable to rename temporary pack file: %s",
 521                                     strerror(errno));
 522                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 523                                  base_name, sha1_to_hex(sha1));
 524                         if (adjust_perm(idx_tmp_name, mode))
 525                                 die("unable to make temporary index file readable: %s",
 526                                     strerror(errno));
 527                         if (rename(idx_tmp_name, tmpname))
 528                                 die("unable to rename temporary index file: %s",
 529                                     strerror(errno));
 530                         free(idx_tmp_name);
 531                         free(pack_tmp_name);
 532                         puts(sha1_to_hex(sha1));
 533                 }
 534
 535                 /* mark written objects as written to previous pack */
 536                 for (j = 0; j < nr_written; j++) {
 537                         written_list[j]->offset = (off_t)-1;
 538                 }
 539                 nr_remaining -= nr_written;
 540         } while (nr_remaining && i < nr_objects);
 541
 542         free(written_list);
 543         stop_progress(&progress_state);
 544         if (written != nr_result)
 545                 die("wrote %u objects while expecting %u", written, nr_result);
 546         /*
 547          * We have scanned through [0 ... i).  Since we have written
 548          * the correct number of objects,  the remaining [i ... nr_objects)
 549          * items must be either already written (due to out-of-order delta base)
 550          * or a preferred base.  Count those which are neither and complain if any.
 551          */
 552         for (j = 0; i < nr_objects; i++) {
 553                 struct object_entry *e = objects + i;
 554                 j += !e->idx.offset && !e->preferred_base;
 555         }
 556         if (j)
 557                 die("wrote %u objects as expected but %u unwritten", written, j);
 558 }
 559
 560 static int locate_object_entry_hash(const unsigned char *sha1)
 561 {
 562         int i;
 563         unsigned int ui;
 564         memcpy(&ui, sha1, sizeof(unsigned int));
 565         i = ui % object_ix_hashsz;
 566         while (0 < object_ix[i]) {
 567                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 568                         return i;
 569                 if (++i == object_ix_hashsz)
 570                         i = 0;
 571         }
 572         return -1 - i;
 573 }
 574
 575 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 576 {
 577         int i;
 578
 579         if (!object_ix_hashsz)
 580                 return NULL;
 581
 582         i = locate_object_entry_hash(sha1);
 583         if (0 <= i)
 584                 return &objects[object_ix[i]-1];
 585         return NULL;
 586 }
 587
 588 static void rehash_objects(void)
 589 {
 590         uint32_t i;
 591         struct object_entry *oe;
 592
 593         object_ix_hashsz = nr_objects * 3;
 594         if (object_ix_hashsz < 1024)
 595                 object_ix_hashsz = 1024;
 596         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 597         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 598         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 599                 int ix = locate_object_entry_hash(oe->idx.sha1);
 600                 if (0 <= ix)
 601                         continue;
 602                 ix = -1 - ix;
 603                 object_ix[ix] = i + 1;
 604         }
 605 }
 606
 607 static unsigned name_hash(const char *name)
 608 {
 609         unsigned char c;
 610         unsigned hash = 0;
 611
 612         if (!name)
 613                 return 0;
 614
 615         /*
 616          * This effectively just creates a sortable number from the
 617          * last sixteen non-whitespace characters. Last characters
 618          * count "most", so things that end in ".c" sort together.
 619          */
 620         while ((c = *name++) != 0) {
 621                 if (isspace(c))
 622                         continue;
 623                 hash = (hash >> 2) + (c << 24);
 624         }
 625         return hash;
 626 }
 627
 628 static void setup_delta_attr_check(struct git_attr_check *check)
 629 {
 630         static struct git_attr *attr_delta;
 631
 632         if (!attr_delta)
 633                 attr_delta = git_attr("delta", 5);
 634
 635         check[0].attr = attr_delta;
 636 }
 637
 638 static int no_try_delta(const char *path)
 639 {
 640         struct git_attr_check check[1];
 641
 642         setup_delta_attr_check(check);
 643         if (git_checkattr(path, ARRAY_SIZE(check), check))
 644                 return 0;
 645         if (ATTR_FALSE(check->value))
 646                 return 1;
 647         return 0;
 648 }
 649
 650 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 651                             const char *name, int exclude)
 652 {
 653         struct object_entry *entry;
 654         struct packed_git *p, *found_pack = NULL;
 655         off_t found_offset = 0;
 656         int ix;
 657         unsigned hash = name_hash(name);
 658
 659         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 660         if (ix >= 0) {
 661                 if (exclude) {
 662                         entry = objects + object_ix[ix] - 1;
 663                         if (!entry->preferred_base)
 664                                 nr_result--;
 665                         entry->preferred_base = 1;
 666                 }
 667                 return 0;
 668         }
 669
 670         for (p = packed_git; p; p = p->next) {
 671                 off_t offset = find_pack_entry_one(sha1, p);
 672                 if (offset) {
 673                         if (!found_pack) {
 674                                 found_offset = offset;
 675                                 found_pack = p;
 676                         }
 677                         if (exclude)
 678                                 break;
 679                         if (incremental)
 680                                 return 0;
 681                         if (local && !p->pack_local)
 682                                 return 0;
 683                 }
 684         }
 685
 686         if (nr_objects >= nr_alloc) {
 687                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 688                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 689         }
 690
 691         entry = objects + nr_objects++;
 692         memset(entry, 0, sizeof(*entry));
 693         hashcpy(entry->idx.sha1, sha1);
 694         entry->hash = hash;
 695         if (type)
 696                 entry->type = type;
 697         if (exclude)
 698                 entry->preferred_base = 1;
 699         else
 700                 nr_result++;
 701         if (found_pack) {
 702                 entry->in_pack = found_pack;
 703                 entry->in_pack_offset = found_offset;
 704         }
 705
 706         if (object_ix_hashsz * 3 <= nr_objects * 4)
 707                 rehash_objects();
 708         else
 709                 object_ix[-1 - ix] = nr_objects;
 710
 711         display_progress(progress_state, nr_objects);
 712
 713         if (name && no_try_delta(name))
 714                 entry->no_try_delta = 1;
 715
 716         return 1;
 717 }
 718
 719 struct pbase_tree_cache {
 720         unsigned char sha1[20];
 721         int ref;
 722         int temporary;
 723         void *tree_data;
 724         unsigned long tree_size;
 725 };
 726
 727 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 728 static int pbase_tree_cache_ix(const unsigned char *sha1)
 729 {
 730         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 731 }
 732 static int pbase_tree_cache_ix_incr(int ix)
 733 {
 734         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 735 }
 736
 737 static struct pbase_tree {
 738         struct pbase_tree *next;
 739         /* This is a phony "cache" entry; we are not
 740          * going to evict it nor find it through _get()
 741          * mechanism -- this is for the toplevel node that
 742          * would almost always change with any commit.
 743          */
 744         struct pbase_tree_cache pcache;
 745 } *pbase_tree;
 746
 747 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 748 {
 749         struct pbase_tree_cache *ent, *nent;
 750         void *data;
 751         unsigned long size;
 752         enum object_type type;
 753         int neigh;
 754         int my_ix = pbase_tree_cache_ix(sha1);
 755         int available_ix = -1;
 756
 757         /* pbase-tree-cache acts as a limited hashtable.
 758          * your object will be found at your index or within a few
 759          * slots after that slot if it is cached.
 760          */
 761         for (neigh = 0; neigh < 8; neigh++) {
 762                 ent = pbase_tree_cache[my_ix];
 763                 if (ent && !hashcmp(ent->sha1, sha1)) {
 764                         ent->ref++;
 765                         return ent;
 766                 }
 767                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 768                          ((0 <= available_ix) &&
 769                           (!ent && pbase_tree_cache[available_ix])))
 770                         available_ix = my_ix;
 771                 if (!ent)
 772                         break;
 773                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 774         }
 775
 776         /* Did not find one.  Either we got a bogus request or
 777          * we need to read and perhaps cache.
 778          */
 779         data = read_sha1_file(sha1, &type, &size);
 780         if (!data)
 781                 return NULL;
 782         if (type != OBJ_TREE) {
 783                 free(data);
 784                 return NULL;
 785         }
 786
 787         /* We need to either cache or return a throwaway copy */
 788
 789         if (available_ix < 0)
 790                 ent = NULL;
 791         else {
 792                 ent = pbase_tree_cache[available_ix];
 793                 my_ix = available_ix;
 794         }
 795
 796         if (!ent) {
 797                 nent = xmalloc(sizeof(*nent));
 798                 nent->temporary = (available_ix < 0);
 799         }
 800         else {
 801                 /* evict and reuse */
 802                 free(ent->tree_data);
 803                 nent = ent;
 804         }
 805         hashcpy(nent->sha1, sha1);
 806         nent->tree_data = data;
 807         nent->tree_size = size;
 808         nent->ref = 1;
 809         if (!nent->temporary)
 810                 pbase_tree_cache[my_ix] = nent;
 811         return nent;
 812 }
 813
 814 static void pbase_tree_put(struct pbase_tree_cache *cache)
 815 {
 816         if (!cache->temporary) {
 817                 cache->ref--;
 818                 return;
 819         }
 820         free(cache->tree_data);
 821         free(cache);
 822 }
 823
 824 static int name_cmp_len(const char *name)
 825 {
 826         int i;
 827         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 828                 ;
 829         return i;
 830 }
 831
 832 static void add_pbase_object(struct tree_desc *tree,
 833                              const char *name,
 834                              int cmplen,
 835                              const char *fullname)
 836 {
 837         struct name_entry entry;
 838         int cmp;
 839
 840         while (tree_entry(tree,&entry)) {
 841                 if (S_ISGITLINK(entry.mode))
 842                         continue;
 843                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 844                       memcmp(name, entry.path, cmplen);
 845                 if (cmp > 0)
 846                         continue;
 847                 if (cmp < 0)
 848                         return;
 849                 if (name[cmplen] != '/') {
 850                         add_object_entry(entry.sha1,
 851                                          object_type(entry.mode),
 852                                          fullname, 1);
 853                         return;
 854                 }
 855                 if (S_ISDIR(entry.mode)) {
 856                         struct tree_desc sub;
 857                         struct pbase_tree_cache *tree;
 858                         const char *down = name+cmplen+1;
 859                         int downlen = name_cmp_len(down);
 860
 861                         tree = pbase_tree_get(entry.sha1);
 862                         if (!tree)
 863                                 return;
 864                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 865
 866                         add_pbase_object(&sub, down, downlen, fullname);
 867                         pbase_tree_put(tree);
 868                 }
 869         }
 870 }
 871
 872 static unsigned *done_pbase_paths;
 873 static int done_pbase_paths_num;
 874 static int done_pbase_paths_alloc;
 875 static int done_pbase_path_pos(unsigned hash)
 876 {
 877         int lo = 0;
 878         int hi = done_pbase_paths_num;
 879         while (lo < hi) {
 880                 int mi = (hi + lo) / 2;
 881                 if (done_pbase_paths[mi] == hash)
 882                         return mi;
 883                 if (done_pbase_paths[mi] < hash)
 884                         hi = mi;
 885                 else
 886                         lo = mi + 1;
 887         }
 888         return -lo-1;
 889 }
 890
 891 static int check_pbase_path(unsigned hash)
 892 {
 893         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 894         if (0 <= pos)
 895                 return 1;
 896         pos = -pos - 1;
 897         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 898                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 899                 done_pbase_paths = xrealloc(done_pbase_paths,
 900                                             done_pbase_paths_alloc *
 901                                             sizeof(unsigned));
 902         }
 903         done_pbase_paths_num++;
 904         if (pos < done_pbase_paths_num)
 905                 memmove(done_pbase_paths + pos + 1,
 906                         done_pbase_paths + pos,
 907                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 908         done_pbase_paths[pos] = hash;
 909         return 0;
 910 }
 911
 912 static void add_preferred_base_object(const char *name)
 913 {
 914         struct pbase_tree *it;
 915         int cmplen;
 916         unsigned hash = name_hash(name);
 917
 918         if (!num_preferred_base || check_pbase_path(hash))
 919                 return;
 920
 921         cmplen = name_cmp_len(name);
 922         for (it = pbase_tree; it; it = it->next) {
 923                 if (cmplen == 0) {
 924                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 925                 }
 926                 else {
 927                         struct tree_desc tree;
 928                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 929                         add_pbase_object(&tree, name, cmplen, name);
 930                 }
 931         }
 932 }
 933
 934 static void add_preferred_base(unsigned char *sha1)
 935 {
 936         struct pbase_tree *it;
 937         void *data;
 938         unsigned long size;
 939         unsigned char tree_sha1[20];
 940
 941         if (window <= num_preferred_base++)
 942                 return;
 943
 944         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 945         if (!data)
 946                 return;
 947
 948         for (it = pbase_tree; it; it = it->next) {
 949                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 950                         free(data);
 951                         return;
 952                 }
 953         }
 954
 955         it = xcalloc(1, sizeof(*it));
 956         it->next = pbase_tree;
 957         pbase_tree = it;
 958
 959         hashcpy(it->pcache.sha1, tree_sha1);
 960         it->pcache.tree_data = data;
 961         it->pcache.tree_size = size;
 962 }
 963
 964 static void check_object(struct object_entry *entry)
 965 {
 966         if (entry->in_pack) {
 967                 struct packed_git *p = entry->in_pack;
 968                 struct pack_window *w_curs = NULL;
 969                 const unsigned char *base_ref = NULL;
 970                 struct object_entry *base_entry;
 971                 unsigned long used, used_0;
 972                 unsigned int avail;
 973                 off_t ofs;
 974                 unsigned char *buf, c;
 975
 976                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
 977
 978                 /*
 979                  * We want in_pack_type even if we do not reuse delta
 980                  * since non-delta representations could still be reused.
 981                  */
 982                 used = unpack_object_header_gently(buf, avail,
 983                                                    &entry->in_pack_type,
 984                                                    &entry->size);
 985
 986                 /*
 987                  * Determine if this is a delta and if so whether we can
 988                  * reuse it or not.  Otherwise let's find out as cheaply as
 989                  * possible what the actual type and size for this object is.
 990                  */
 991                 switch (entry->in_pack_type) {
 992                 default:
 993                         /* Not a delta hence we've already got all we need. */
 994                         entry->type = entry->in_pack_type;
 995                         entry->in_pack_header_size = used;
 996                         unuse_pack(&w_curs);
 997                         return;
 998                 case OBJ_REF_DELTA:
 999                         if (!no_reuse_delta && !entry->preferred_base)
1000                                 base_ref = use_pack(p, &w_curs,
1001                                                 entry->in_pack_offset + used, NULL);
1002                         entry->in_pack_header_size = used + 20;
1003                         break;
1004                 case OBJ_OFS_DELTA:
1005                         buf = use_pack(p, &w_curs,
1006                                        entry->in_pack_offset + used, NULL);
1007                         used_0 = 0;
1008                         c = buf[used_0++];
1009                         ofs = c & 127;
1010                         while (c & 128) {
1011                                 ofs += 1;
1012                                 if (!ofs || MSB(ofs, 7))
1013                                         die("delta base offset overflow in pack for %s",
1014                                             sha1_to_hex(entry->idx.sha1));
1015                                 c = buf[used_0++];
1016                                 ofs = (ofs << 7) + (c & 127);
1017                         }
1018                         if (ofs >= entry->in_pack_offset)
1019                                 die("delta base offset out of bound for %s",
1020                                     sha1_to_hex(entry->idx.sha1));
1021                         ofs = entry->in_pack_offset - ofs;
1022                         if (!no_reuse_delta && !entry->preferred_base) {
1023                                 struct revindex_entry *revidx;
1024                                 revidx = find_pack_revindex(p, ofs);
1025                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1026                         }
1027                         entry->in_pack_header_size = used + used_0;
1028                         break;
1029                 }
1030
1031                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1032                         /*
1033                          * If base_ref was set above that means we wish to
1034                          * reuse delta data, and we even found that base
1035                          * in the list of objects we want to pack. Goodie!
1036                          *
1037                          * Depth value does not matter - find_deltas() will
1038                          * never consider reused delta as the base object to
1039                          * deltify other objects against, in order to avoid
1040                          * circular deltas.
1041                          */
1042                         entry->type = entry->in_pack_type;
1043                         entry->delta = base_entry;
1044                         entry->delta_sibling = base_entry->delta_child;
1045                         base_entry->delta_child = entry;
1046                         unuse_pack(&w_curs);
1047                         return;
1048                 }
1049
1050                 if (entry->type) {
1051                         /*
1052                          * This must be a delta and we already know what the
1053                          * final object type is.  Let's extract the actual
1054                          * object size from the delta header.
1055                          */
1056                         entry->size = get_size_from_delta(p, &w_curs,
1057                                         entry->in_pack_offset + entry->in_pack_header_size);
1058                         unuse_pack(&w_curs);
1059                         return;
1060                 }
1061
1062                 /*
1063                  * No choice but to fall back to the recursive delta walk
1064                  * with sha1_object_info() to find about the object type
1065                  * at this point...
1066                  */
1067                 unuse_pack(&w_curs);
1068         }
1069
1070         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1071         if (entry->type < 0)
1072                 die("unable to get type of object %s",
1073                     sha1_to_hex(entry->idx.sha1));
1074 }
1075
1076 static int pack_offset_sort(const void *_a, const void *_b)
1077 {
1078         const struct object_entry *a = *(struct object_entry **)_a;
1079         const struct object_entry *b = *(struct object_entry **)_b;
1080
1081         /* avoid filesystem trashing with loose objects */
1082         if (!a->in_pack && !b->in_pack)
1083                 return hashcmp(a->idx.sha1, b->idx.sha1);
1084
1085         if (a->in_pack < b->in_pack)
1086                 return -1;
1087         if (a->in_pack > b->in_pack)
1088                 return 1;
1089         return a->in_pack_offset < b->in_pack_offset ? -1 :
1090                         (a->in_pack_offset > b->in_pack_offset);
1091 }
1092
1093 static void get_object_details(void)
1094 {
1095         uint32_t i;
1096         struct object_entry **sorted_by_offset;
1097
1098         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1099         for (i = 0; i < nr_objects; i++)
1100                 sorted_by_offset[i] = objects + i;
1101         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1102
1103         init_pack_revindex();
1104
1105         for (i = 0; i < nr_objects; i++)
1106                 check_object(sorted_by_offset[i]);
1107
1108         free(sorted_by_offset);
1109 }
1110
1111 /*
1112  * We search for deltas in a list sorted by type, by filename hash, and then
1113  * by size, so that we see progressively smaller and smaller files.
1114  * That's because we prefer deltas to be from the bigger file
1115  * to the smaller -- deletes are potentially cheaper, but perhaps
1116  * more importantly, the bigger file is likely the more recent
1117  * one.  The deepest deltas are therefore the oldest objects which are
1118  * less susceptible to be accessed often.
1119  */
1120 static int type_size_sort(const void *_a, const void *_b)
1121 {
1122         const struct object_entry *a = *(struct object_entry **)_a;
1123         const struct object_entry *b = *(struct object_entry **)_b;
1124
1125         if (a->type > b->type)
1126                 return -1;
1127         if (a->type < b->type)
1128                 return 1;
1129         if (a->hash > b->hash)
1130                 return -1;
1131         if (a->hash < b->hash)
1132                 return 1;
1133         if (a->preferred_base > b->preferred_base)
1134                 return -1;
1135         if (a->preferred_base < b->preferred_base)
1136                 return 1;
1137         if (a->size > b->size)
1138                 return -1;
1139         if (a->size < b->size)
1140                 return 1;
1141         return a < b ? -1 : (a > b);  /* newest first */
1142 }
1143
1144 struct unpacked {
1145         struct object_entry *entry;
1146         void *data;
1147         struct delta_index *index;
1148         unsigned depth;
1149 };
1150
1151 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1152                            unsigned long delta_size)
1153 {
1154         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1155                 return 0;
1156
1157         if (delta_size < cache_max_small_delta_size)
1158                 return 1;
1159
1160         /* cache delta, if objects are large enough compared to delta size */
1161         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1162                 return 1;
1163
1164         return 0;
1165 }
1166
1167 #ifdef THREADED_DELTA_SEARCH
1168
1169 static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1170 #define read_lock()             pthread_mutex_lock(&read_mutex)
1171 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1172
1173 static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1174 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1175 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1176
1177 static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1178 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1179 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1180
1181 #else
1182
1183 #define read_lock()             (void)0
1184 #define read_unlock()           (void)0
1185 #define cache_lock()            (void)0
1186 #define cache_unlock()          (void)0
1187 #define progress_lock()         (void)0
1188 #define progress_unlock()       (void)0
1189
1190 #endif
1191
1192 static int try_delta(struct unpacked *trg, struct unpacked *src,
1193                      unsigned max_depth, unsigned long *mem_usage)
1194 {
1195         struct object_entry *trg_entry = trg->entry;
1196         struct object_entry *src_entry = src->entry;
1197         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1198         unsigned ref_depth;
1199         enum object_type type;
1200         void *delta_buf;
1201
1202         /* Don't bother doing diffs between different types */
1203         if (trg_entry->type != src_entry->type)
1204                 return -1;
1205
1206         /*
1207          * We do not bother to try a delta that we discarded
1208          * on an earlier try, but only when reusing delta data.
1209          */
1210         if (!no_reuse_delta && trg_entry->in_pack &&
1211             trg_entry->in_pack == src_entry->in_pack &&
1212             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1213             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1214                 return 0;
1215
1216         /* Let's not bust the allowed depth. */
1217         if (src->depth >= max_depth)
1218                 return 0;
1219
1220         /* Now some size filtering heuristics. */
1221         trg_size = trg_entry->size;
1222         if (!trg_entry->delta) {
1223                 max_size = trg_size/2 - 20;
1224                 ref_depth = 1;
1225         } else {
1226                 max_size = trg_entry->delta_size;
1227                 ref_depth = trg->depth;
1228         }
1229         max_size = max_size * (max_depth - src->depth) /
1230                                                 (max_depth - ref_depth + 1);
1231         if (max_size == 0)
1232                 return 0;
1233         src_size = src_entry->size;
1234         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1235         if (sizediff >= max_size)
1236                 return 0;
1237         if (trg_size < src_size / 32)
1238                 return 0;
1239
1240         /* Load data if not already done */
1241         if (!trg->data) {
1242                 read_lock();
1243                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1244                 read_unlock();
1245                 if (!trg->data)
1246                         die("object %s cannot be read",
1247                             sha1_to_hex(trg_entry->idx.sha1));
1248                 if (sz != trg_size)
1249                         die("object %s inconsistent object length (%lu vs %lu)",
1250                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1251                 *mem_usage += sz;
1252         }
1253         if (!src->data) {
1254                 read_lock();
1255                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1256                 read_unlock();
1257                 if (!src->data)
1258                         die("object %s cannot be read",
1259                             sha1_to_hex(src_entry->idx.sha1));
1260                 if (sz != src_size)
1261                         die("object %s inconsistent object length (%lu vs %lu)",
1262                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1263                 *mem_usage += sz;
1264         }
1265         if (!src->index) {
1266                 src->index = create_delta_index(src->data, src_size);
1267                 if (!src->index) {
1268                         static int warned = 0;
1269                         if (!warned++)
1270                                 warning("suboptimal pack - out of memory");
1271                         return 0;
1272                 }
1273                 *mem_usage += sizeof_delta_index(src->index);
1274         }
1275
1276         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1277         if (!delta_buf)
1278                 return 0;
1279
1280         if (trg_entry->delta) {
1281                 /* Prefer only shallower same-sized deltas. */
1282                 if (delta_size == trg_entry->delta_size &&
1283                     src->depth + 1 >= trg->depth) {
1284                         free(delta_buf);
1285                         return 0;
1286                 }
1287         }
1288
1289         /*
1290          * Handle memory allocation outside of the cache
1291          * accounting lock.  Compiler will optimize the strangeness
1292          * away when THREADED_DELTA_SEARCH is not defined.
1293          */
1294         free(trg_entry->delta_data);
1295         cache_lock();
1296         if (trg_entry->delta_data) {
1297                 delta_cache_size -= trg_entry->delta_size;
1298                 trg_entry->delta_data = NULL;
1299         }
1300         if (delta_cacheable(src_size, trg_size, delta_size)) {
1301                 delta_cache_size += delta_size;
1302                 cache_unlock();
1303                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1304         } else {
1305                 cache_unlock();
1306                 free(delta_buf);
1307         }
1308
1309         trg_entry->delta = src_entry;
1310         trg_entry->delta_size = delta_size;
1311         trg->depth = src->depth + 1;
1312
1313         return 1;
1314 }
1315
1316 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1317 {
1318         struct object_entry *child = me->delta_child;
1319         unsigned int m = n;
1320         while (child) {
1321                 unsigned int c = check_delta_limit(child, n + 1);
1322                 if (m < c)
1323                         m = c;
1324                 child = child->delta_sibling;
1325         }
1326         return m;
1327 }
1328
1329 static unsigned long free_unpacked(struct unpacked *n)
1330 {
1331         unsigned long freed_mem = sizeof_delta_index(n->index);
1332         free_delta_index(n->index);
1333         n->index = NULL;
1334         if (n->data) {
1335                 freed_mem += n->entry->size;
1336                 free(n->data);
1337                 n->data = NULL;
1338         }
1339         n->entry = NULL;
1340         n->depth = 0;
1341         return freed_mem;
1342 }
1343
1344 static void find_deltas(struct object_entry **list, unsigned *list_size,
1345                         int window, int depth, unsigned *processed)
1346 {
1347         uint32_t i, idx = 0, count = 0;
1348         unsigned int array_size = window * sizeof(struct unpacked);
1349         struct unpacked *array;
1350         unsigned long mem_usage = 0;
1351
1352         array = xmalloc(array_size);
1353         memset(array, 0, array_size);
1354
1355         for (;;) {
1356                 struct object_entry *entry = *list++;
1357                 struct unpacked *n = array + idx;
1358                 int j, max_depth, best_base = -1;
1359
1360                 progress_lock();
1361                 if (!*list_size) {
1362                         progress_unlock();
1363                         break;
1364                 }
1365                 (*list_size)--;
1366                 if (!entry->preferred_base) {
1367                         (*processed)++;
1368                         display_progress(progress_state, *processed);
1369                 }
1370                 progress_unlock();
1371
1372                 mem_usage -= free_unpacked(n);
1373                 n->entry = entry;
1374
1375                 while (window_memory_limit &&
1376                        mem_usage > window_memory_limit &&
1377                        count > 1) {
1378                         uint32_t tail = (idx + window - count) % window;
1379                         mem_usage -= free_unpacked(array + tail);
1380                         count--;
1381                 }
1382
1383                 /* We do not compute delta to *create* objects we are not
1384                  * going to pack.
1385                  */
1386                 if (entry->preferred_base)
1387                         goto next;
1388
1389                 /*
1390                  * If the current object is at pack edge, take the depth the
1391                  * objects that depend on the current object into account
1392                  * otherwise they would become too deep.
1393                  */
1394                 max_depth = depth;
1395                 if (entry->delta_child) {
1396                         max_depth -= check_delta_limit(entry, 0);
1397                         if (max_depth <= 0)
1398                                 goto next;
1399                 }
1400
1401                 j = window;
1402                 while (--j > 0) {
1403                         int ret;
1404                         uint32_t other_idx = idx + j;
1405                         struct unpacked *m;
1406                         if (other_idx >= window)
1407                                 other_idx -= window;
1408                         m = array + other_idx;
1409                         if (!m->entry)
1410                                 break;
1411                         ret = try_delta(n, m, max_depth, &mem_usage);
1412                         if (ret < 0)
1413                                 break;
1414                         else if (ret > 0)
1415                                 best_base = other_idx;
1416                 }
1417
1418                 /* if we made n a delta, and if n is already at max
1419                  * depth, leaving it in the window is pointless.  we
1420                  * should evict it first.
1421                  */
1422                 if (entry->delta && depth <= n->depth)
1423                         continue;
1424
1425                 /*
1426                  * Move the best delta base up in the window, after the
1427                  * currently deltified object, to keep it longer.  It will
1428                  * be the first base object to be attempted next.
1429                  */
1430                 if (entry->delta) {
1431                         struct unpacked swap = array[best_base];
1432                         int dist = (window + idx - best_base) % window;
1433                         int dst = best_base;
1434                         while (dist--) {
1435                                 int src = (dst + 1) % window;
1436                                 array[dst] = array[src];
1437                                 dst = src;
1438                         }
1439                         array[dst] = swap;
1440                 }
1441
1442                 next:
1443                 idx++;
1444                 if (count + 1 < window)
1445                         count++;
1446                 if (idx >= window)
1447                         idx = 0;
1448         }
1449
1450         for (i = 0; i < window; ++i) {
1451                 free_delta_index(array[i].index);
1452                 free(array[i].data);
1453         }
1454         free(array);
1455 }
1456
1457 #ifdef THREADED_DELTA_SEARCH
1458
1459 /*
1460  * The main thread waits on the condition that (at least) one of the workers
1461  * has stopped working (which is indicated in the .working member of
1462  * struct thread_params).
1463  * When a work thread has completed its work, it sets .working to 0 and
1464  * signals the main thread and waits on the condition that .data_ready
1465  * becomes 1.
1466  */
1467
1468 struct thread_params {
1469         pthread_t thread;
1470         struct object_entry **list;
1471         unsigned list_size;
1472         unsigned remaining;
1473         int window;
1474         int depth;
1475         int working;
1476         int data_ready;
1477         pthread_mutex_t mutex;
1478         pthread_cond_t cond;
1479         unsigned *processed;
1480 };
1481
1482 static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
1483
1484 static void *threaded_find_deltas(void *arg)
1485 {
1486         struct thread_params *me = arg;
1487
1488         while (me->remaining) {
1489                 find_deltas(me->list, &me->remaining,
1490                             me->window, me->depth, me->processed);
1491
1492                 progress_lock();
1493                 me->working = 0;
1494                 pthread_cond_signal(&progress_cond);
1495                 progress_unlock();
1496
1497                 /*
1498                  * We must not set ->data_ready before we wait on the
1499                  * condition because the main thread may have set it to 1
1500                  * before we get here. In order to be sure that new
1501                  * work is available if we see 1 in ->data_ready, it
1502                  * was initialized to 0 before this thread was spawned
1503                  * and we reset it to 0 right away.
1504                  */
1505                 pthread_mutex_lock(&me->mutex);
1506                 while (!me->data_ready)
1507                         pthread_cond_wait(&me->cond, &me->mutex);
1508                 me->data_ready = 0;
1509                 pthread_mutex_unlock(&me->mutex);
1510         }
1511         /* leave ->working 1 so that this doesn't get more work assigned */
1512         return NULL;
1513 }
1514
1515 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1516                            int window, int depth, unsigned *processed)
1517 {
1518         struct thread_params p[delta_search_threads];
1519         int i, ret, active_threads = 0;
1520
1521         if (delta_search_threads <= 1) {
1522                 find_deltas(list, &list_size, window, depth, processed);
1523                 return;
1524         }
1525
1526         /* Partition the work amongst work threads. */
1527         for (i = 0; i < delta_search_threads; i++) {
1528                 unsigned sub_size = list_size / (delta_search_threads - i);
1529
1530                 p[i].window = window;
1531                 p[i].depth = depth;
1532                 p[i].processed = processed;
1533                 p[i].working = 1;
1534                 p[i].data_ready = 0;
1535
1536                 /* try to split chunks on "path" boundaries */
1537                 while (sub_size && sub_size < list_size &&
1538                        list[sub_size]->hash &&
1539                        list[sub_size]->hash == list[sub_size-1]->hash)
1540                         sub_size++;
1541
1542                 p[i].list = list;
1543                 p[i].list_size = sub_size;
1544                 p[i].remaining = sub_size;
1545
1546                 list += sub_size;
1547                 list_size -= sub_size;
1548         }
1549
1550         /* Start work threads. */
1551         for (i = 0; i < delta_search_threads; i++) {
1552                 if (!p[i].list_size)
1553                         continue;
1554                 pthread_mutex_init(&p[i].mutex, NULL);
1555                 pthread_cond_init(&p[i].cond, NULL);
1556                 ret = pthread_create(&p[i].thread, NULL,
1557                                      threaded_find_deltas, &p[i]);
1558                 if (ret)
1559                         die("unable to create thread: %s", strerror(ret));
1560                 active_threads++;
1561         }
1562
1563         /*
1564          * Now let's wait for work completion.  Each time a thread is done
1565          * with its work, we steal half of the remaining work from the
1566          * thread with the largest number of unprocessed objects and give
1567          * it to that newly idle thread.  This ensure good load balancing
1568          * until the remaining object list segments are simply too short
1569          * to be worth splitting anymore.
1570          */
1571         while (active_threads) {
1572                 struct thread_params *target = NULL;
1573                 struct thread_params *victim = NULL;
1574                 unsigned sub_size = 0;
1575
1576                 progress_lock();
1577                 for (;;) {
1578                         for (i = 0; !target && i < delta_search_threads; i++)
1579                                 if (!p[i].working)
1580                                         target = &p[i];
1581                         if (target)
1582                                 break;
1583                         pthread_cond_wait(&progress_cond, &progress_mutex);
1584                 }
1585
1586                 for (i = 0; i < delta_search_threads; i++)
1587                         if (p[i].remaining > 2*window &&
1588                             (!victim || victim->remaining < p[i].remaining))
1589                                 victim = &p[i];
1590                 if (victim) {
1591                         sub_size = victim->remaining / 2;
1592                         list = victim->list + victim->list_size - sub_size;
1593                         while (sub_size && list[0]->hash &&
1594                                list[0]->hash == list[-1]->hash) {
1595                                 list++;
1596                                 sub_size--;
1597                         }
1598                         if (!sub_size) {
1599                                 /*
1600                                  * It is possible for some "paths" to have
1601                                  * so many objects that no hash boundary
1602                                  * might be found.  Let's just steal the
1603                                  * exact half in that case.
1604                                  */
1605                                 sub_size = victim->remaining / 2;
1606                                 list -= sub_size;
1607                         }
1608                         target->list = list;
1609                         victim->list_size -= sub_size;
1610                         victim->remaining -= sub_size;
1611                 }
1612                 target->list_size = sub_size;
1613                 target->remaining = sub_size;
1614                 target->working = 1;
1615                 progress_unlock();
1616
1617                 pthread_mutex_lock(&target->mutex);
1618                 target->data_ready = 1;
1619                 pthread_cond_signal(&target->cond);
1620                 pthread_mutex_unlock(&target->mutex);
1621
1622                 if (!sub_size) {
1623                         pthread_join(target->thread, NULL);
1624                         pthread_cond_destroy(&target->cond);
1625                         pthread_mutex_destroy(&target->mutex);
1626                         active_threads--;
1627                 }
1628         }
1629 }
1630
1631 #else
1632 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1633 #endif
1634
1635 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1636 {
1637         unsigned char peeled[20];
1638
1639         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1640             !peel_ref(path, peeled)        && /* peelable? */
1641             !is_null_sha1(peeled)          && /* annotated tag? */
1642             locate_object_entry(peeled))      /* object packed? */
1643                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1644         return 0;
1645 }
1646
1647 static void prepare_pack(int window, int depth)
1648 {
1649         struct object_entry **delta_list;
1650         uint32_t i, n, nr_deltas;
1651
1652         get_object_details();
1653
1654         if (!nr_objects || !window || !depth)
1655                 return;
1656
1657         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1658         nr_deltas = n = 0;
1659
1660         for (i = 0; i < nr_objects; i++) {
1661                 struct object_entry *entry = objects + i;
1662
1663                 if (entry->delta)
1664                         /* This happens if we decided to reuse existing
1665                          * delta from a pack.  "!no_reuse_delta &&" is implied.
1666                          */
1667                         continue;
1668
1669                 if (entry->size < 50)
1670                         continue;
1671
1672                 if (entry->no_try_delta)
1673                         continue;
1674
1675                 if (!entry->preferred_base)
1676                         nr_deltas++;
1677
1678                 delta_list[n++] = entry;
1679         }
1680
1681         if (nr_deltas && n > 1) {
1682                 unsigned nr_done = 0;
1683                 if (progress)
1684                         progress_state = start_progress("Compressing objects",
1685                                                         nr_deltas);
1686                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1687                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1688                 stop_progress(&progress_state);
1689                 if (nr_done != nr_deltas)
1690                         die("inconsistency with delta count");
1691         }
1692         free(delta_list);
1693 }
1694
1695 static int git_pack_config(const char *k, const char *v)
1696 {
1697         if(!strcmp(k, "pack.window")) {
1698                 window = git_config_int(k, v);
1699                 return 0;
1700         }
1701         if (!strcmp(k, "pack.windowmemory")) {
1702                 window_memory_limit = git_config_ulong(k, v);
1703                 return 0;
1704         }
1705         if (!strcmp(k, "pack.depth")) {
1706                 depth = git_config_int(k, v);
1707                 return 0;
1708         }
1709         if (!strcmp(k, "pack.compression")) {
1710                 int level = git_config_int(k, v);
1711                 if (level == -1)
1712                         level = Z_DEFAULT_COMPRESSION;
1713                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1714                         die("bad pack compression level %d", level);
1715                 pack_compression_level = level;
1716                 pack_compression_seen = 1;
1717                 return 0;
1718         }
1719         if (!strcmp(k, "pack.deltacachesize")) {
1720                 max_delta_cache_size = git_config_int(k, v);
1721                 return 0;
1722         }
1723         if (!strcmp(k, "pack.deltacachelimit")) {
1724                 cache_max_small_delta_size = git_config_int(k, v);
1725                 return 0;
1726         }
1727         if (!strcmp(k, "pack.threads")) {
1728                 delta_search_threads = git_config_int(k, v);
1729                 if (delta_search_threads < 0)
1730                         die("invalid number of threads specified (%d)",
1731                             delta_search_threads);
1732 #ifndef THREADED_DELTA_SEARCH
1733                 if (delta_search_threads != 1)
1734                         warning("no threads support, ignoring %s", k);
1735 #endif
1736                 return 0;
1737         }
1738         if (!strcmp(k, "pack.indexversion")) {
1739                 pack_idx_default_version = git_config_int(k, v);
1740                 if (pack_idx_default_version > 2)
1741                         die("bad pack.indexversion=%d", pack_idx_default_version);
1742                 return 0;
1743         }
1744         if (!strcmp(k, "pack.packsizelimit")) {
1745                 pack_size_limit_cfg = git_config_ulong(k, v);
1746                 return 0;
1747         }
1748         return git_default_config(k, v);
1749 }
1750
1751 static void read_object_list_from_stdin(void)
1752 {
1753         char line[40 + 1 + PATH_MAX + 2];
1754         unsigned char sha1[20];
1755
1756         for (;;) {
1757                 if (!fgets(line, sizeof(line), stdin)) {
1758                         if (feof(stdin))
1759                                 break;
1760                         if (!ferror(stdin))
1761                                 die("fgets returned NULL, not EOF, not error!");
1762                         if (errno != EINTR)
1763                                 die("fgets: %s", strerror(errno));
1764                         clearerr(stdin);
1765                         continue;
1766                 }
1767                 if (line[0] == '-') {
1768                         if (get_sha1_hex(line+1, sha1))
1769                                 die("expected edge sha1, got garbage:\n %s",
1770                                     line);
1771                         add_preferred_base(sha1);
1772                         continue;
1773                 }
1774                 if (get_sha1_hex(line, sha1))
1775                         die("expected sha1, got garbage:\n %s", line);
1776
1777                 add_preferred_base_object(line+41);
1778                 add_object_entry(sha1, 0, line+41, 0);
1779         }
1780 }
1781
1782 #define OBJECT_ADDED (1u<<20)
1783
1784 static void show_commit(struct commit *commit)
1785 {
1786         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1787         commit->object.flags |= OBJECT_ADDED;
1788 }
1789
1790 static void show_object(struct object_array_entry *p)
1791 {
1792         add_preferred_base_object(p->name);
1793         add_object_entry(p->item->sha1, p->item->type, p->name, 0);
1794         p->item->flags |= OBJECT_ADDED;
1795 }
1796
1797 static void show_edge(struct commit *commit)
1798 {
1799         add_preferred_base(commit->object.sha1);
1800 }
1801
1802 struct in_pack_object {
1803         off_t offset;
1804         struct object *object;
1805 };
1806
1807 struct in_pack {
1808         int alloc;
1809         int nr;
1810         struct in_pack_object *array;
1811 };
1812
1813 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1814 {
1815         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1816         in_pack->array[in_pack->nr].object = object;
1817         in_pack->nr++;
1818 }
1819
1820 /*
1821  * Compare the objects in the offset order, in order to emulate the
1822  * "git-rev-list --objects" output that produced the pack originally.
1823  */
1824 static int ofscmp(const void *a_, const void *b_)
1825 {
1826         struct in_pack_object *a = (struct in_pack_object *)a_;
1827         struct in_pack_object *b = (struct in_pack_object *)b_;
1828
1829         if (a->offset < b->offset)
1830                 return -1;
1831         else if (a->offset > b->offset)
1832                 return 1;
1833         else
1834                 return hashcmp(a->object->sha1, b->object->sha1);
1835 }
1836
1837 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1838 {
1839         struct packed_git *p;
1840         struct in_pack in_pack;
1841         uint32_t i;
1842
1843         memset(&in_pack, 0, sizeof(in_pack));
1844
1845         for (p = packed_git; p; p = p->next) {
1846                 const unsigned char *sha1;
1847                 struct object *o;
1848
1849                 for (i = 0; i < revs->num_ignore_packed; i++) {
1850                         if (matches_pack_name(p, revs->ignore_packed[i]))
1851                                 break;
1852                 }
1853                 if (revs->num_ignore_packed <= i)
1854                         continue;
1855                 if (open_pack_index(p))
1856                         die("cannot open pack index");
1857
1858                 ALLOC_GROW(in_pack.array,
1859                            in_pack.nr + p->num_objects,
1860                            in_pack.alloc);
1861
1862                 for (i = 0; i < p->num_objects; i++) {
1863                         sha1 = nth_packed_object_sha1(p, i);
1864                         o = lookup_unknown_object(sha1);
1865                         if (!(o->flags & OBJECT_ADDED))
1866                                 mark_in_pack_object(o, p, &in_pack);
1867                         o->flags |= OBJECT_ADDED;
1868                 }
1869         }
1870
1871         if (in_pack.nr) {
1872                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
1873                       ofscmp);
1874                 for (i = 0; i < in_pack.nr; i++) {
1875                         struct object *o = in_pack.array[i].object;
1876                         add_object_entry(o->sha1, o->type, "", 0);
1877                 }
1878         }
1879         free(in_pack.array);
1880 }
1881
1882 static void get_object_list(int ac, const char **av)
1883 {
1884         struct rev_info revs;
1885         char line[1000];
1886         int flags = 0;
1887
1888         init_revisions(&revs, NULL);
1889         save_commit_buffer = 0;
1890         setup_revisions(ac, av, &revs, NULL);
1891
1892         while (fgets(line, sizeof(line), stdin) != NULL) {
1893                 int len = strlen(line);
1894                 if (len && line[len - 1] == '\n')
1895                         line[--len] = 0;
1896                 if (!len)
1897                         break;
1898                 if (*line == '-') {
1899                         if (!strcmp(line, "--not")) {
1900                                 flags ^= UNINTERESTING;
1901                                 continue;
1902                         }
1903                         die("not a rev '%s'", line);
1904                 }
1905                 if (handle_revision_arg(line, &revs, flags, 1))
1906                         die("bad revision '%s'", line);
1907         }
1908
1909         if (prepare_revision_walk(&revs))
1910                 die("revision walk setup failed");
1911         mark_edges_uninteresting(revs.commits, &revs, show_edge);
1912         traverse_commit_list(&revs, show_commit, show_object);
1913
1914         if (keep_unreachable)
1915                 add_objects_in_unpacked_packs(&revs);
1916 }
1917
1918 static int adjust_perm(const char *path, mode_t mode)
1919 {
1920         if (chmod(path, mode))
1921                 return -1;
1922         return adjust_shared_perm(path);
1923 }
1924
1925 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
1926 {
1927         int use_internal_rev_list = 0;
1928         int thin = 0;
1929         uint32_t i;
1930         const char **rp_av;
1931         int rp_ac_alloc = 64;
1932         int rp_ac;
1933
1934         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
1935
1936         rp_av[0] = "pack-objects";
1937         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
1938         rp_ac = 2;
1939
1940         git_config(git_pack_config);
1941         if (!pack_compression_seen && core_compression_seen)
1942                 pack_compression_level = core_compression_level;
1943
1944         progress = isatty(2);
1945         for (i = 1; i < argc; i++) {
1946                 const char *arg = argv[i];
1947
1948                 if (*arg != '-')
1949                         break;
1950
1951                 if (!strcmp("--non-empty", arg)) {
1952                         non_empty = 1;
1953                         continue;
1954                 }
1955                 if (!strcmp("--local", arg)) {
1956                         local = 1;
1957                         continue;
1958                 }
1959                 if (!strcmp("--incremental", arg)) {
1960                         incremental = 1;
1961                         continue;
1962                 }
1963                 if (!prefixcmp(arg, "--compression=")) {
1964                         char *end;
1965                         int level = strtoul(arg+14, &end, 0);
1966                         if (!arg[14] || *end)
1967                                 usage(pack_usage);
1968                         if (level == -1)
1969                                 level = Z_DEFAULT_COMPRESSION;
1970                         else if (level < 0 || level > Z_BEST_COMPRESSION)
1971                                 die("bad pack compression level %d", level);
1972                         pack_compression_level = level;
1973                         continue;
1974                 }
1975                 if (!prefixcmp(arg, "--max-pack-size=")) {
1976                         char *end;
1977                         pack_size_limit_cfg = 0;
1978                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
1979                         if (!arg[16] || *end)
1980                                 usage(pack_usage);
1981                         continue;
1982                 }
1983                 if (!prefixcmp(arg, "--window=")) {
1984                         char *end;
1985                         window = strtoul(arg+9, &end, 0);
1986                         if (!arg[9] || *end)
1987                                 usage(pack_usage);
1988                         continue;
1989                 }
1990                 if (!prefixcmp(arg, "--window-memory=")) {
1991                         if (!git_parse_ulong(arg+16, &window_memory_limit))
1992                                 usage(pack_usage);
1993                         continue;
1994                 }
1995                 if (!prefixcmp(arg, "--threads=")) {
1996                         char *end;
1997                         delta_search_threads = strtoul(arg+10, &end, 0);
1998                         if (!arg[10] || *end || delta_search_threads < 0)
1999                                 usage(pack_usage);
2000 #ifndef THREADED_DELTA_SEARCH
2001                         if (delta_search_threads != 1)
2002                                 warning("no threads support, "
2003                                         "ignoring %s", arg);
2004 #endif
2005                         continue;
2006                 }
2007                 if (!prefixcmp(arg, "--depth=")) {
2008                         char *end;
2009                         depth = strtoul(arg+8, &end, 0);
2010                         if (!arg[8] || *end)
2011                                 usage(pack_usage);
2012                         continue;
2013                 }
2014                 if (!strcmp("--progress", arg)) {
2015                         progress = 1;
2016                         continue;
2017                 }
2018                 if (!strcmp("--all-progress", arg)) {
2019                         progress = 2;
2020                         continue;
2021                 }
2022                 if (!strcmp("-q", arg)) {
2023                         progress = 0;
2024                         continue;
2025                 }
2026                 if (!strcmp("--no-reuse-delta", arg)) {
2027                         no_reuse_delta = 1;
2028                         continue;
2029                 }
2030                 if (!strcmp("--no-reuse-object", arg)) {
2031                         no_reuse_object = no_reuse_delta = 1;
2032                         continue;
2033                 }
2034                 if (!strcmp("--delta-base-offset", arg)) {
2035                         allow_ofs_delta = 1;
2036                         continue;
2037                 }
2038                 if (!strcmp("--stdout", arg)) {
2039                         pack_to_stdout = 1;
2040                         continue;
2041                 }
2042                 if (!strcmp("--revs", arg)) {
2043                         use_internal_rev_list = 1;
2044                         continue;
2045                 }
2046                 if (!strcmp("--keep-unreachable", arg)) {
2047                         keep_unreachable = 1;
2048                         continue;
2049                 }
2050                 if (!strcmp("--include-tag", arg)) {
2051                         include_tag = 1;
2052                         continue;
2053                 }
2054                 if (!strcmp("--unpacked", arg) ||
2055                     !prefixcmp(arg, "--unpacked=") ||
2056                     !strcmp("--reflog", arg) ||
2057                     !strcmp("--all", arg)) {
2058                         use_internal_rev_list = 1;
2059                         if (rp_ac >= rp_ac_alloc - 1) {
2060                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2061                                 rp_av = xrealloc(rp_av,
2062                                                  rp_ac_alloc * sizeof(*rp_av));
2063                         }
2064                         rp_av[rp_ac++] = arg;
2065                         continue;
2066                 }
2067                 if (!strcmp("--thin", arg)) {
2068                         use_internal_rev_list = 1;
2069                         thin = 1;
2070                         rp_av[1] = "--objects-edge";
2071                         continue;
2072                 }
2073                 if (!prefixcmp(arg, "--index-version=")) {
2074                         char *c;
2075                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2076                         if (pack_idx_default_version > 2)
2077                                 die("bad %s", arg);
2078                         if (*c == ',')
2079                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2080                         if (*c || pack_idx_off32_limit & 0x80000000)
2081                                 die("bad %s", arg);
2082                         continue;
2083                 }
2084                 usage(pack_usage);
2085         }
2086
2087         /* Traditionally "pack-objects [options] base extra" failed;
2088          * we would however want to take refs parameter that would
2089          * have been given to upstream rev-list ourselves, which means
2090          * we somehow want to say what the base name is.  So the
2091          * syntax would be:
2092          *
2093          * pack-objects [options] base <refs...>
2094          *
2095          * in other words, we would treat the first non-option as the
2096          * base_name and send everything else to the internal revision
2097          * walker.
2098          */
2099
2100         if (!pack_to_stdout)
2101                 base_name = argv[i++];
2102
2103         if (pack_to_stdout != !base_name)
2104                 usage(pack_usage);
2105
2106         if (!pack_to_stdout && !pack_size_limit)
2107                 pack_size_limit = pack_size_limit_cfg;
2108
2109         if (pack_to_stdout && pack_size_limit)
2110                 die("--max-pack-size cannot be used to build a pack for transfer.");
2111
2112         if (!pack_to_stdout && thin)
2113                 die("--thin cannot be used to build an indexable pack.");
2114
2115 #ifdef THREADED_DELTA_SEARCH
2116         if (!delta_search_threads)      /* --threads=0 means autodetect */
2117                 delta_search_threads = online_cpus();
2118 #endif
2119
2120         prepare_packed_git();
2121
2122         if (progress)
2123                 progress_state = start_progress("Counting objects", 0);
2124         if (!use_internal_rev_list)
2125                 read_object_list_from_stdin();
2126         else {
2127                 rp_av[rp_ac] = NULL;
2128                 get_object_list(rp_ac, rp_av);
2129         }
2130         if (include_tag && nr_result)
2131                 for_each_ref(add_ref_tag, NULL);
2132         stop_progress(&progress_state);
2133
2134         if (non_empty && !nr_result)
2135                 return 0;
2136         if (nr_result)
2137                 prepare_pack(window, depth);
2138         write_pack_file();
2139         if (progress)
2140                 fprintf(stderr, "Total %u (delta %u), reused %u (delta %u)\n",
2141                         written, written_delta, reused, reused_delta);
2142         return 0;
2143 }