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 #include "thread-utils.h"
  20
  21 static const char pack_usage[] =
  22   "git pack-objects [ -q | --progress | --all-progress ]\n"
  23   "        [--all-progress-implied]\n"
  24   "        [--max-pack-size=<n>] [--local] [--incremental]\n"
  25   "        [--window=<n>] [--window-memory=<n>] [--depth=<n>]\n"
  26   "        [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset]\n"
  27   "        [--threads=<n>] [--non-empty] [--revs [--unpacked | --all]]\n"
  28   "        [--reflog] [--stdout | base-name] [--include-tag]\n"
  29   "        [--keep-unreachable | --unpack-unreachable]\n"
  30   "        [< ref-list | < object-list]";
  31
  32 struct object_entry {
  33         struct pack_idx_entry idx;
  34         unsigned long size;     /* uncompressed size */
  35         struct packed_git *in_pack;     /* already in pack */
  36         off_t in_pack_offset;
  37         struct object_entry *delta;     /* delta base object */
  38         struct object_entry *delta_child; /* deltified objects who bases me */
  39         struct object_entry *delta_sibling; /* other deltified objects who
  40                                              * uses the same base as me
  41                                              */
  42         void *delta_data;       /* cached delta (uncompressed) */
  43         unsigned long delta_size;       /* delta data size (uncompressed) */
  44         unsigned long z_delta_size;     /* delta data size (compressed) */
  45         unsigned int hash;      /* name hint hash */
  46         enum object_type type;
  47         enum object_type in_pack_type;  /* could be delta */
  48         unsigned char in_pack_header_size;
  49         unsigned char preferred_base; /* we do not pack this, but is available
  50                                        * to be used as the base object to delta
  51                                        * objects against.
  52                                        */
  53         unsigned char no_try_delta;
  54 };
  55
  56 /*
  57  * Objects we are going to pack are collected in objects array (dynamically
  58  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  59  * in the order we see -- typically rev-list --objects order that gives us
  60  * nice "minimum seek" order.
  61  */
  62 static struct object_entry *objects;
  63 static struct pack_idx_entry **written_list;
  64 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
  65
  66 static int non_empty;
  67 static int reuse_delta = 1, reuse_object = 1;
  68 static int keep_unreachable, unpack_unreachable, include_tag;
  69 static int local;
  70 static int incremental;
  71 static int ignore_packed_keep;
  72 static int allow_ofs_delta;
  73 static const char *base_name;
  74 static int progress = 1;
  75 static int window = 10;
  76 static unsigned long pack_size_limit, pack_size_limit_cfg;
  77 static int depth = 50;
  78 static int delta_search_threads;
  79 static int pack_to_stdout;
  80 static int num_preferred_base;
  81 static struct progress *progress_state;
  82 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  83 static int pack_compression_seen;
  84
  85 static unsigned long delta_cache_size = 0;
  86 static unsigned long max_delta_cache_size = 256 * 1024 * 1024;
  87 static unsigned long cache_max_small_delta_size = 1000;
  88
  89 static unsigned long window_memory_limit = 0;
  90
  91 /*
  92  * The object names in objects array are hashed with this hashtable,
  93  * to help looking up the entry by object name.
  94  * This hashtable is built after all the objects are seen.
  95  */
  96 static int *object_ix;
  97 static int object_ix_hashsz;
  98
  99 /*
 100  * stats
 101  */
 102 static uint32_t written, written_delta;
 103 static uint32_t reused, reused_delta;
 104
 105
 106 static void *get_delta(struct object_entry *entry)
 107 {
 108         unsigned long size, base_size, delta_size;
 109         void *buf, *base_buf, *delta_buf;
 110         enum object_type type;
 111
 112         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 113         if (!buf)
 114                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 115         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
 116         if (!base_buf)
 117                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 118         delta_buf = diff_delta(base_buf, base_size,
 119                                buf, size, &delta_size, 0);
 120         if (!delta_buf || delta_size != entry->delta_size)
 121                 die("delta size changed");
 122         free(buf);
 123         free(base_buf);
 124         return delta_buf;
 125 }
 126
 127 static unsigned long do_compress(void **pptr, unsigned long size)
 128 {
 129         z_stream stream;
 130         void *in, *out;
 131         unsigned long maxsize;
 132
 133         memset(&stream, 0, sizeof(stream));
 134         deflateInit(&stream, pack_compression_level);
 135         maxsize = deflateBound(&stream, size);
 136
 137         in = *pptr;
 138         out = xmalloc(maxsize);
 139         *pptr = out;
 140
 141         stream.next_in = in;
 142         stream.avail_in = size;
 143         stream.next_out = out;
 144         stream.avail_out = maxsize;
 145         while (deflate(&stream, Z_FINISH) == Z_OK)
 146                 ; /* nothing */
 147         deflateEnd(&stream);
 148
 149         free(in);
 150         return stream.total_out;
 151 }
 152
 153 /*
 154  * we are going to reuse the existing object data as is.  make
 155  * sure it is not corrupt.
 156  */
 157 static int check_pack_inflate(struct packed_git *p,
 158                 struct pack_window **w_curs,
 159                 off_t offset,
 160                 off_t len,
 161                 unsigned long expect)
 162 {
 163         z_stream stream;
 164         unsigned char fakebuf[4096], *in;
 165         int st;
 166
 167         memset(&stream, 0, sizeof(stream));
 168         git_inflate_init(&stream);
 169         do {
 170                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 171                 stream.next_in = in;
 172                 stream.next_out = fakebuf;
 173                 stream.avail_out = sizeof(fakebuf);
 174                 st = git_inflate(&stream, Z_FINISH);
 175                 offset += stream.next_in - in;
 176         } while (st == Z_OK || st == Z_BUF_ERROR);
 177         git_inflate_end(&stream);
 178         return (st == Z_STREAM_END &&
 179                 stream.total_out == expect &&
 180                 stream.total_in == len) ? 0 : -1;
 181 }
 182
 183 static void copy_pack_data(struct sha1file *f,
 184                 struct packed_git *p,
 185                 struct pack_window **w_curs,
 186                 off_t offset,
 187                 off_t len)
 188 {
 189         unsigned char *in;
 190         unsigned int avail;
 191
 192         while (len) {
 193                 in = use_pack(p, w_curs, offset, &avail);
 194                 if (avail > len)
 195                         avail = (unsigned int)len;
 196                 sha1write(f, in, avail);
 197                 offset += avail;
 198                 len -= avail;
 199         }
 200 }
 201
 202 static unsigned long write_object(struct sha1file *f,
 203                                   struct object_entry *entry,
 204                                   off_t write_offset)
 205 {
 206         unsigned long size, limit, datalen;
 207         void *buf;
 208         unsigned char header[10], dheader[10];
 209         unsigned hdrlen;
 210         enum object_type type;
 211         int usable_delta, to_reuse;
 212
 213         if (!pack_to_stdout)
 214                 crc32_begin(f);
 215
 216         type = entry->type;
 217
 218         /* apply size limit if limited packsize and not first object */
 219         if (!pack_size_limit || !nr_written)
 220                 limit = 0;
 221         else if (pack_size_limit <= write_offset)
 222                 /*
 223                  * the earlier object did not fit the limit; avoid
 224                  * mistaking this with unlimited (i.e. limit = 0).
 225                  */
 226                 limit = 1;
 227         else
 228                 limit = pack_size_limit - write_offset;
 229
 230         if (!entry->delta)
 231                 usable_delta = 0;       /* no delta */
 232         else if (!pack_size_limit)
 233                usable_delta = 1;        /* unlimited packfile */
 234         else if (entry->delta->idx.offset == (off_t)-1)
 235                 usable_delta = 0;       /* base was written to another pack */
 236         else if (entry->delta->idx.offset)
 237                 usable_delta = 1;       /* base already exists in this pack */
 238         else
 239                 usable_delta = 0;       /* base could end up in another pack */
 240
 241         if (!reuse_object)
 242                 to_reuse = 0;   /* explicit */
 243         else if (!entry->in_pack)
 244                 to_reuse = 0;   /* can't reuse what we don't have */
 245         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
 246                                 /* check_object() decided it for us ... */
 247                 to_reuse = usable_delta;
 248                                 /* ... but pack split may override that */
 249         else if (type != entry->in_pack_type)
 250                 to_reuse = 0;   /* pack has delta which is unusable */
 251         else if (entry->delta)
 252                 to_reuse = 0;   /* we want to pack afresh */
 253         else
 254                 to_reuse = 1;   /* we have it in-pack undeltified,
 255                                  * and we do not need to deltify it.
 256                                  */
 257
 258         if (!to_reuse) {
 259                 no_reuse:
 260                 if (!usable_delta) {
 261                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 262                         if (!buf)
 263                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 264                         /*
 265                          * make sure no cached delta data remains from a
 266                          * previous attempt before a pack split occurred.
 267                          */
 268                         free(entry->delta_data);
 269                         entry->delta_data = NULL;
 270                         entry->z_delta_size = 0;
 271                 } else if (entry->delta_data) {
 272                         size = entry->delta_size;
 273                         buf = entry->delta_data;
 274                         entry->delta_data = NULL;
 275                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 276                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 277                 } else {
 278                         buf = get_delta(entry);
 279                         size = entry->delta_size;
 280                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 281                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 282                 }
 283
 284                 if (entry->z_delta_size)
 285                         datalen = entry->z_delta_size;
 286                 else
 287                         datalen = do_compress(&buf, size);
 288
 289                 /*
 290                  * The object header is a byte of 'type' followed by zero or
 291                  * more bytes of length.
 292                  */
 293                 hdrlen = encode_in_pack_object_header(type, size, header);
 294
 295                 if (type == OBJ_OFS_DELTA) {
 296                         /*
 297                          * Deltas with relative base contain an additional
 298                          * encoding of the relative offset for the delta
 299                          * base from this object's position in the pack.
 300                          */
 301                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 302                         unsigned pos = sizeof(dheader) - 1;
 303                         dheader[pos] = ofs & 127;
 304                         while (ofs >>= 7)
 305                                 dheader[--pos] = 128 | (--ofs & 127);
 306                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 307                                 free(buf);
 308                                 return 0;
 309                         }
 310                         sha1write(f, header, hdrlen);
 311                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 312                         hdrlen += sizeof(dheader) - pos;
 313                 } else if (type == OBJ_REF_DELTA) {
 314                         /*
 315                          * Deltas with a base reference contain
 316                          * an additional 20 bytes for the base sha1.
 317                          */
 318                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 319                                 free(buf);
 320                                 return 0;
 321                         }
 322                         sha1write(f, header, hdrlen);
 323                         sha1write(f, entry->delta->idx.sha1, 20);
 324                         hdrlen += 20;
 325                 } else {
 326                         if (limit && hdrlen + datalen + 20 >= limit) {
 327                                 free(buf);
 328                                 return 0;
 329                         }
 330                         sha1write(f, header, hdrlen);
 331                 }
 332                 sha1write(f, buf, datalen);
 333                 free(buf);
 334         }
 335         else {
 336                 struct packed_git *p = entry->in_pack;
 337                 struct pack_window *w_curs = NULL;
 338                 struct revindex_entry *revidx;
 339                 off_t offset;
 340
 341                 if (entry->delta)
 342                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 343                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 344                 hdrlen = encode_in_pack_object_header(type, entry->size, header);
 345
 346                 offset = entry->in_pack_offset;
 347                 revidx = find_pack_revindex(p, offset);
 348                 datalen = revidx[1].offset - offset;
 349                 if (!pack_to_stdout && p->index_version > 1 &&
 350                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 351                         error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 352                         unuse_pack(&w_curs);
 353                         goto no_reuse;
 354                 }
 355
 356                 offset += entry->in_pack_header_size;
 357                 datalen -= entry->in_pack_header_size;
 358                 if (!pack_to_stdout && p->index_version == 1 &&
 359                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
 360                         error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 361                         unuse_pack(&w_curs);
 362                         goto no_reuse;
 363                 }
 364
 365                 if (type == OBJ_OFS_DELTA) {
 366                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 367                         unsigned pos = sizeof(dheader) - 1;
 368                         dheader[pos] = ofs & 127;
 369                         while (ofs >>= 7)
 370                                 dheader[--pos] = 128 | (--ofs & 127);
 371                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 372                                 unuse_pack(&w_curs);
 373                                 return 0;
 374                         }
 375                         sha1write(f, header, hdrlen);
 376                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 377                         hdrlen += sizeof(dheader) - pos;
 378                         reused_delta++;
 379                 } else if (type == OBJ_REF_DELTA) {
 380                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 381                                 unuse_pack(&w_curs);
 382                                 return 0;
 383                         }
 384                         sha1write(f, header, hdrlen);
 385                         sha1write(f, entry->delta->idx.sha1, 20);
 386                         hdrlen += 20;
 387                         reused_delta++;
 388                 } else {
 389                         if (limit && hdrlen + datalen + 20 >= limit) {
 390                                 unuse_pack(&w_curs);
 391                                 return 0;
 392                         }
 393                         sha1write(f, header, hdrlen);
 394                 }
 395                 copy_pack_data(f, p, &w_curs, offset, datalen);
 396                 unuse_pack(&w_curs);
 397                 reused++;
 398         }
 399         if (usable_delta)
 400                 written_delta++;
 401         written++;
 402         if (!pack_to_stdout)
 403                 entry->idx.crc32 = crc32_end(f);
 404         return hdrlen + datalen;
 405 }
 406
 407 static int write_one(struct sha1file *f,
 408                                struct object_entry *e,
 409                                off_t *offset)
 410 {
 411         unsigned long size;
 412
 413         /* offset is non zero if object is written already. */
 414         if (e->idx.offset || e->preferred_base)
 415                 return -1;
 416
 417         /* if we are deltified, write out base object first. */
 418         if (e->delta && !write_one(f, e->delta, offset))
 419                 return 0;
 420
 421         e->idx.offset = *offset;
 422         size = write_object(f, e, *offset);
 423         if (!size) {
 424                 e->idx.offset = 0;
 425                 return 0;
 426         }
 427         written_list[nr_written++] = &e->idx;
 428
 429         /* make sure off_t is sufficiently large not to wrap */
 430         if (signed_add_overflows(*offset, size))
 431                 die("pack too large for current definition of off_t");
 432         *offset += size;
 433         return 1;
 434 }
 435
 436 static void write_pack_file(void)
 437 {
 438         uint32_t i = 0, j;
 439         struct sha1file *f;
 440         off_t offset;
 441         struct pack_header hdr;
 442         uint32_t nr_remaining = nr_result;
 443         time_t last_mtime = 0;
 444
 445         if (progress > pack_to_stdout)
 446                 progress_state = start_progress("Writing objects", nr_result);
 447         written_list = xmalloc(nr_objects * sizeof(*written_list));
 448
 449         do {
 450                 unsigned char sha1[20];
 451                 char *pack_tmp_name = NULL;
 452
 453                 if (pack_to_stdout) {
 454                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 455                 } else {
 456                         char tmpname[PATH_MAX];
 457                         int fd;
 458                         fd = odb_mkstemp(tmpname, sizeof(tmpname),
 459                                          "pack/tmp_pack_XXXXXX");
 460                         pack_tmp_name = xstrdup(tmpname);
 461                         f = sha1fd(fd, pack_tmp_name);
 462                 }
 463
 464                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
 465                 hdr.hdr_version = htonl(PACK_VERSION);
 466                 hdr.hdr_entries = htonl(nr_remaining);
 467                 sha1write(f, &hdr, sizeof(hdr));
 468                 offset = sizeof(hdr);
 469                 nr_written = 0;
 470                 for (; i < nr_objects; i++) {
 471                         if (!write_one(f, objects + i, &offset))
 472                                 break;
 473                         display_progress(progress_state, written);
 474                 }
 475
 476                 /*
 477                  * Did we write the wrong # entries in the header?
 478                  * If so, rewrite it like in fast-import
 479                  */
 480                 if (pack_to_stdout) {
 481                         sha1close(f, sha1, CSUM_CLOSE);
 482                 } else if (nr_written == nr_remaining) {
 483                         sha1close(f, sha1, CSUM_FSYNC);
 484                 } else {
 485                         int fd = sha1close(f, sha1, 0);
 486                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
 487                                                  nr_written, sha1, offset);
 488                         close(fd);
 489                 }
 490
 491                 if (!pack_to_stdout) {
 492                         struct stat st;
 493                         const char *idx_tmp_name;
 494                         char tmpname[PATH_MAX];
 495
 496                         idx_tmp_name = write_idx_file(NULL, written_list,
 497                                                       nr_written, sha1);
 498
 499                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 500                                  base_name, sha1_to_hex(sha1));
 501                         free_pack_by_name(tmpname);
 502                         if (adjust_shared_perm(pack_tmp_name))
 503                                 die_errno("unable to make temporary pack file readable");
 504                         if (rename(pack_tmp_name, tmpname))
 505                                 die_errno("unable to rename temporary pack file");
 506
 507                         /*
 508                          * Packs are runtime accessed in their mtime
 509                          * order since newer packs are more likely to contain
 510                          * younger objects.  So if we are creating multiple
 511                          * packs then we should modify the mtime of later ones
 512                          * to preserve this property.
 513                          */
 514                         if (stat(tmpname, &st) < 0) {
 515                                 warning("failed to stat %s: %s",
 516                                         tmpname, strerror(errno));
 517                         } else if (!last_mtime) {
 518                                 last_mtime = st.st_mtime;
 519                         } else {
 520                                 struct utimbuf utb;
 521                                 utb.actime = st.st_atime;
 522                                 utb.modtime = --last_mtime;
 523                                 if (utime(tmpname, &utb) < 0)
 524                                         warning("failed utime() on %s: %s",
 525                                                 tmpname, strerror(errno));
 526                         }
 527
 528                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 529                                  base_name, sha1_to_hex(sha1));
 530                         if (adjust_shared_perm(idx_tmp_name))
 531                                 die_errno("unable to make temporary index file readable");
 532                         if (rename(idx_tmp_name, tmpname))
 533                                 die_errno("unable to rename temporary index file");
 534
 535                         free((void *) idx_tmp_name);
 536                         free(pack_tmp_name);
 537                         puts(sha1_to_hex(sha1));
 538                 }
 539
 540                 /* mark written objects as written to previous pack */
 541                 for (j = 0; j < nr_written; j++) {
 542                         written_list[j]->offset = (off_t)-1;
 543                 }
 544                 nr_remaining -= nr_written;
 545         } while (nr_remaining && i < nr_objects);
 546
 547         free(written_list);
 548         stop_progress(&progress_state);
 549         if (written != nr_result)
 550                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
 551                         written, nr_result);
 552 }
 553
 554 static int locate_object_entry_hash(const unsigned char *sha1)
 555 {
 556         int i;
 557         unsigned int ui;
 558         memcpy(&ui, sha1, sizeof(unsigned int));
 559         i = ui % object_ix_hashsz;
 560         while (0 < object_ix[i]) {
 561                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 562                         return i;
 563                 if (++i == object_ix_hashsz)
 564                         i = 0;
 565         }
 566         return -1 - i;
 567 }
 568
 569 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 570 {
 571         int i;
 572
 573         if (!object_ix_hashsz)
 574                 return NULL;
 575
 576         i = locate_object_entry_hash(sha1);
 577         if (0 <= i)
 578                 return &objects[object_ix[i]-1];
 579         return NULL;
 580 }
 581
 582 static void rehash_objects(void)
 583 {
 584         uint32_t i;
 585         struct object_entry *oe;
 586
 587         object_ix_hashsz = nr_objects * 3;
 588         if (object_ix_hashsz < 1024)
 589                 object_ix_hashsz = 1024;
 590         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 591         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 592         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 593                 int ix = locate_object_entry_hash(oe->idx.sha1);
 594                 if (0 <= ix)
 595                         continue;
 596                 ix = -1 - ix;
 597                 object_ix[ix] = i + 1;
 598         }
 599 }
 600
 601 static unsigned name_hash(const char *name)
 602 {
 603         unsigned c, hash = 0;
 604
 605         if (!name)
 606                 return 0;
 607
 608         /*
 609          * This effectively just creates a sortable number from the
 610          * last sixteen non-whitespace characters. Last characters
 611          * count "most", so things that end in ".c" sort together.
 612          */
 613         while ((c = *name++) != 0) {
 614                 if (isspace(c))
 615                         continue;
 616                 hash = (hash >> 2) + (c << 24);
 617         }
 618         return hash;
 619 }
 620
 621 static void setup_delta_attr_check(struct git_attr_check *check)
 622 {
 623         static struct git_attr *attr_delta;
 624
 625         if (!attr_delta)
 626                 attr_delta = git_attr("delta");
 627
 628         check[0].attr = attr_delta;
 629 }
 630
 631 static int no_try_delta(const char *path)
 632 {
 633         struct git_attr_check check[1];
 634
 635         setup_delta_attr_check(check);
 636         if (git_checkattr(path, ARRAY_SIZE(check), check))
 637                 return 0;
 638         if (ATTR_FALSE(check->value))
 639                 return 1;
 640         return 0;
 641 }
 642
 643 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 644                             const char *name, int exclude)
 645 {
 646         struct object_entry *entry;
 647         struct packed_git *p, *found_pack = NULL;
 648         off_t found_offset = 0;
 649         int ix;
 650         unsigned hash = name_hash(name);
 651
 652         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 653         if (ix >= 0) {
 654                 if (exclude) {
 655                         entry = objects + object_ix[ix] - 1;
 656                         if (!entry->preferred_base)
 657                                 nr_result--;
 658                         entry->preferred_base = 1;
 659                 }
 660                 return 0;
 661         }
 662
 663         if (!exclude && local && has_loose_object_nonlocal(sha1))
 664                 return 0;
 665
 666         for (p = packed_git; p; p = p->next) {
 667                 off_t offset = find_pack_entry_one(sha1, p);
 668                 if (offset) {
 669                         if (!found_pack) {
 670                                 found_offset = offset;
 671                                 found_pack = p;
 672                         }
 673                         if (exclude)
 674                                 break;
 675                         if (incremental)
 676                                 return 0;
 677                         if (local && !p->pack_local)
 678                                 return 0;
 679                         if (ignore_packed_keep && p->pack_local && p->pack_keep)
 680                                 return 0;
 681                 }
 682         }
 683
 684         if (nr_objects >= nr_alloc) {
 685                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 686                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 687         }
 688
 689         entry = objects + nr_objects++;
 690         memset(entry, 0, sizeof(*entry));
 691         hashcpy(entry->idx.sha1, sha1);
 692         entry->hash = hash;
 693         if (type)
 694                 entry->type = type;
 695         if (exclude)
 696                 entry->preferred_base = 1;
 697         else
 698                 nr_result++;
 699         if (found_pack) {
 700                 entry->in_pack = found_pack;
 701                 entry->in_pack_offset = found_offset;
 702         }
 703
 704         if (object_ix_hashsz * 3 <= nr_objects * 4)
 705                 rehash_objects();
 706         else
 707                 object_ix[-1 - ix] = nr_objects;
 708
 709         display_progress(progress_state, nr_objects);
 710
 711         if (name && no_try_delta(name))
 712                 entry->no_try_delta = 1;
 713
 714         return 1;
 715 }
 716
 717 struct pbase_tree_cache {
 718         unsigned char sha1[20];
 719         int ref;
 720         int temporary;
 721         void *tree_data;
 722         unsigned long tree_size;
 723 };
 724
 725 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 726 static int pbase_tree_cache_ix(const unsigned char *sha1)
 727 {
 728         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 729 }
 730 static int pbase_tree_cache_ix_incr(int ix)
 731 {
 732         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 733 }
 734
 735 static struct pbase_tree {
 736         struct pbase_tree *next;
 737         /* This is a phony "cache" entry; we are not
 738          * going to evict it nor find it through _get()
 739          * mechanism -- this is for the toplevel node that
 740          * would almost always change with any commit.
 741          */
 742         struct pbase_tree_cache pcache;
 743 } *pbase_tree;
 744
 745 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 746 {
 747         struct pbase_tree_cache *ent, *nent;
 748         void *data;
 749         unsigned long size;
 750         enum object_type type;
 751         int neigh;
 752         int my_ix = pbase_tree_cache_ix(sha1);
 753         int available_ix = -1;
 754
 755         /* pbase-tree-cache acts as a limited hashtable.
 756          * your object will be found at your index or within a few
 757          * slots after that slot if it is cached.
 758          */
 759         for (neigh = 0; neigh < 8; neigh++) {
 760                 ent = pbase_tree_cache[my_ix];
 761                 if (ent && !hashcmp(ent->sha1, sha1)) {
 762                         ent->ref++;
 763                         return ent;
 764                 }
 765                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 766                          ((0 <= available_ix) &&
 767                           (!ent && pbase_tree_cache[available_ix])))
 768                         available_ix = my_ix;
 769                 if (!ent)
 770                         break;
 771                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 772         }
 773
 774         /* Did not find one.  Either we got a bogus request or
 775          * we need to read and perhaps cache.
 776          */
 777         data = read_sha1_file(sha1, &type, &size);
 778         if (!data)
 779                 return NULL;
 780         if (type != OBJ_TREE) {
 781                 free(data);
 782                 return NULL;
 783         }
 784
 785         /* We need to either cache or return a throwaway copy */
 786
 787         if (available_ix < 0)
 788                 ent = NULL;
 789         else {
 790                 ent = pbase_tree_cache[available_ix];
 791                 my_ix = available_ix;
 792         }
 793
 794         if (!ent) {
 795                 nent = xmalloc(sizeof(*nent));
 796                 nent->temporary = (available_ix < 0);
 797         }
 798         else {
 799                 /* evict and reuse */
 800                 free(ent->tree_data);
 801                 nent = ent;
 802         }
 803         hashcpy(nent->sha1, sha1);
 804         nent->tree_data = data;
 805         nent->tree_size = size;
 806         nent->ref = 1;
 807         if (!nent->temporary)
 808                 pbase_tree_cache[my_ix] = nent;
 809         return nent;
 810 }
 811
 812 static void pbase_tree_put(struct pbase_tree_cache *cache)
 813 {
 814         if (!cache->temporary) {
 815                 cache->ref--;
 816                 return;
 817         }
 818         free(cache->tree_data);
 819         free(cache);
 820 }
 821
 822 static int name_cmp_len(const char *name)
 823 {
 824         int i;
 825         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 826                 ;
 827         return i;
 828 }
 829
 830 static void add_pbase_object(struct tree_desc *tree,
 831                              const char *name,
 832                              int cmplen,
 833                              const char *fullname)
 834 {
 835         struct name_entry entry;
 836         int cmp;
 837
 838         while (tree_entry(tree,&entry)) {
 839                 if (S_ISGITLINK(entry.mode))
 840                         continue;
 841                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 842                       memcmp(name, entry.path, cmplen);
 843                 if (cmp > 0)
 844                         continue;
 845                 if (cmp < 0)
 846                         return;
 847                 if (name[cmplen] != '/') {
 848                         add_object_entry(entry.sha1,
 849                                          object_type(entry.mode),
 850                                          fullname, 1);
 851                         return;
 852                 }
 853                 if (S_ISDIR(entry.mode)) {
 854                         struct tree_desc sub;
 855                         struct pbase_tree_cache *tree;
 856                         const char *down = name+cmplen+1;
 857                         int downlen = name_cmp_len(down);
 858
 859                         tree = pbase_tree_get(entry.sha1);
 860                         if (!tree)
 861                                 return;
 862                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 863
 864                         add_pbase_object(&sub, down, downlen, fullname);
 865                         pbase_tree_put(tree);
 866                 }
 867         }
 868 }
 869
 870 static unsigned *done_pbase_paths;
 871 static int done_pbase_paths_num;
 872 static int done_pbase_paths_alloc;
 873 static int done_pbase_path_pos(unsigned hash)
 874 {
 875         int lo = 0;
 876         int hi = done_pbase_paths_num;
 877         while (lo < hi) {
 878                 int mi = (hi + lo) / 2;
 879                 if (done_pbase_paths[mi] == hash)
 880                         return mi;
 881                 if (done_pbase_paths[mi] < hash)
 882                         hi = mi;
 883                 else
 884                         lo = mi + 1;
 885         }
 886         return -lo-1;
 887 }
 888
 889 static int check_pbase_path(unsigned hash)
 890 {
 891         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 892         if (0 <= pos)
 893                 return 1;
 894         pos = -pos - 1;
 895         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 896                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 897                 done_pbase_paths = xrealloc(done_pbase_paths,
 898                                             done_pbase_paths_alloc *
 899                                             sizeof(unsigned));
 900         }
 901         done_pbase_paths_num++;
 902         if (pos < done_pbase_paths_num)
 903                 memmove(done_pbase_paths + pos + 1,
 904                         done_pbase_paths + pos,
 905                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 906         done_pbase_paths[pos] = hash;
 907         return 0;
 908 }
 909
 910 static void add_preferred_base_object(const char *name)
 911 {
 912         struct pbase_tree *it;
 913         int cmplen;
 914         unsigned hash = name_hash(name);
 915
 916         if (!num_preferred_base || check_pbase_path(hash))
 917                 return;
 918
 919         cmplen = name_cmp_len(name);
 920         for (it = pbase_tree; it; it = it->next) {
 921                 if (cmplen == 0) {
 922                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 923                 }
 924                 else {
 925                         struct tree_desc tree;
 926                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 927                         add_pbase_object(&tree, name, cmplen, name);
 928                 }
 929         }
 930 }
 931
 932 static void add_preferred_base(unsigned char *sha1)
 933 {
 934         struct pbase_tree *it;
 935         void *data;
 936         unsigned long size;
 937         unsigned char tree_sha1[20];
 938
 939         if (window <= num_preferred_base++)
 940                 return;
 941
 942         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 943         if (!data)
 944                 return;
 945
 946         for (it = pbase_tree; it; it = it->next) {
 947                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 948                         free(data);
 949                         return;
 950                 }
 951         }
 952
 953         it = xcalloc(1, sizeof(*it));
 954         it->next = pbase_tree;
 955         pbase_tree = it;
 956
 957         hashcpy(it->pcache.sha1, tree_sha1);
 958         it->pcache.tree_data = data;
 959         it->pcache.tree_size = size;
 960 }
 961
 962 static void cleanup_preferred_base(void)
 963 {
 964         struct pbase_tree *it;
 965         unsigned i;
 966
 967         it = pbase_tree;
 968         pbase_tree = NULL;
 969         while (it) {
 970                 struct pbase_tree *this = it;
 971                 it = this->next;
 972                 free(this->pcache.tree_data);
 973                 free(this);
 974         }
 975
 976         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
 977                 if (!pbase_tree_cache[i])
 978                         continue;
 979                 free(pbase_tree_cache[i]->tree_data);
 980                 free(pbase_tree_cache[i]);
 981                 pbase_tree_cache[i] = NULL;
 982         }
 983
 984         free(done_pbase_paths);
 985         done_pbase_paths = NULL;
 986         done_pbase_paths_num = done_pbase_paths_alloc = 0;
 987 }
 988
 989 static void check_object(struct object_entry *entry)
 990 {
 991         if (entry->in_pack) {
 992                 struct packed_git *p = entry->in_pack;
 993                 struct pack_window *w_curs = NULL;
 994                 const unsigned char *base_ref = NULL;
 995                 struct object_entry *base_entry;
 996                 unsigned long used, used_0;
 997                 unsigned int avail;
 998                 off_t ofs;
 999                 unsigned char *buf, c;
1000
1001                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1002
1003                 /*
1004                  * We want in_pack_type even if we do not reuse delta
1005                  * since non-delta representations could still be reused.
1006                  */
1007                 used = unpack_object_header_buffer(buf, avail,
1008                                                    &entry->in_pack_type,
1009                                                    &entry->size);
1010                 if (used == 0)
1011                         goto give_up;
1012
1013                 /*
1014                  * Determine if this is a delta and if so whether we can
1015                  * reuse it or not.  Otherwise let's find out as cheaply as
1016                  * possible what the actual type and size for this object is.
1017                  */
1018                 switch (entry->in_pack_type) {
1019                 default:
1020                         /* Not a delta hence we've already got all we need. */
1021                         entry->type = entry->in_pack_type;
1022                         entry->in_pack_header_size = used;
1023                         if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1024                                 goto give_up;
1025                         unuse_pack(&w_curs);
1026                         return;
1027                 case OBJ_REF_DELTA:
1028                         if (reuse_delta && !entry->preferred_base)
1029                                 base_ref = use_pack(p, &w_curs,
1030                                                 entry->in_pack_offset + used, NULL);
1031                         entry->in_pack_header_size = used + 20;
1032                         break;
1033                 case OBJ_OFS_DELTA:
1034                         buf = use_pack(p, &w_curs,
1035                                        entry->in_pack_offset + used, NULL);
1036                         used_0 = 0;
1037                         c = buf[used_0++];
1038                         ofs = c & 127;
1039                         while (c & 128) {
1040                                 ofs += 1;
1041                                 if (!ofs || MSB(ofs, 7)) {
1042                                         error("delta base offset overflow in pack for %s",
1043                                               sha1_to_hex(entry->idx.sha1));
1044                                         goto give_up;
1045                                 }
1046                                 c = buf[used_0++];
1047                                 ofs = (ofs << 7) + (c & 127);
1048                         }
1049                         ofs = entry->in_pack_offset - ofs;
1050                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1051                                 error("delta base offset out of bound for %s",
1052                                       sha1_to_hex(entry->idx.sha1));
1053                                 goto give_up;
1054                         }
1055                         if (reuse_delta && !entry->preferred_base) {
1056                                 struct revindex_entry *revidx;
1057                                 revidx = find_pack_revindex(p, ofs);
1058                                 if (!revidx)
1059                                         goto give_up;
1060                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1061                         }
1062                         entry->in_pack_header_size = used + used_0;
1063                         break;
1064                 }
1065
1066                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1067                         /*
1068                          * If base_ref was set above that means we wish to
1069                          * reuse delta data, and we even found that base
1070                          * in the list of objects we want to pack. Goodie!
1071                          *
1072                          * Depth value does not matter - find_deltas() will
1073                          * never consider reused delta as the base object to
1074                          * deltify other objects against, in order to avoid
1075                          * circular deltas.
1076                          */
1077                         entry->type = entry->in_pack_type;
1078                         entry->delta = base_entry;
1079                         entry->delta_size = entry->size;
1080                         entry->delta_sibling = base_entry->delta_child;
1081                         base_entry->delta_child = entry;
1082                         unuse_pack(&w_curs);
1083                         return;
1084                 }
1085
1086                 if (entry->type) {
1087                         /*
1088                          * This must be a delta and we already know what the
1089                          * final object type is.  Let's extract the actual
1090                          * object size from the delta header.
1091                          */
1092                         entry->size = get_size_from_delta(p, &w_curs,
1093                                         entry->in_pack_offset + entry->in_pack_header_size);
1094                         if (entry->size == 0)
1095                                 goto give_up;
1096                         unuse_pack(&w_curs);
1097                         return;
1098                 }
1099
1100                 /*
1101                  * No choice but to fall back to the recursive delta walk
1102                  * with sha1_object_info() to find about the object type
1103                  * at this point...
1104                  */
1105                 give_up:
1106                 unuse_pack(&w_curs);
1107         }
1108
1109         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1110         /*
1111          * The error condition is checked in prepare_pack().  This is
1112          * to permit a missing preferred base object to be ignored
1113          * as a preferred base.  Doing so can result in a larger
1114          * pack file, but the transfer will still take place.
1115          */
1116 }
1117
1118 static int pack_offset_sort(const void *_a, const void *_b)
1119 {
1120         const struct object_entry *a = *(struct object_entry **)_a;
1121         const struct object_entry *b = *(struct object_entry **)_b;
1122
1123         /* avoid filesystem trashing with loose objects */
1124         if (!a->in_pack && !b->in_pack)
1125                 return hashcmp(a->idx.sha1, b->idx.sha1);
1126
1127         if (a->in_pack < b->in_pack)
1128                 return -1;
1129         if (a->in_pack > b->in_pack)
1130                 return 1;
1131         return a->in_pack_offset < b->in_pack_offset ? -1 :
1132                         (a->in_pack_offset > b->in_pack_offset);
1133 }
1134
1135 static void get_object_details(void)
1136 {
1137         uint32_t i;
1138         struct object_entry **sorted_by_offset;
1139
1140         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1141         for (i = 0; i < nr_objects; i++)
1142                 sorted_by_offset[i] = objects + i;
1143         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1144
1145         for (i = 0; i < nr_objects; i++)
1146                 check_object(sorted_by_offset[i]);
1147
1148         free(sorted_by_offset);
1149 }
1150
1151 /*
1152  * We search for deltas in a list sorted by type, by filename hash, and then
1153  * by size, so that we see progressively smaller and smaller files.
1154  * That's because we prefer deltas to be from the bigger file
1155  * to the smaller -- deletes are potentially cheaper, but perhaps
1156  * more importantly, the bigger file is likely the more recent
1157  * one.  The deepest deltas are therefore the oldest objects which are
1158  * less susceptible to be accessed often.
1159  */
1160 static int type_size_sort(const void *_a, const void *_b)
1161 {
1162         const struct object_entry *a = *(struct object_entry **)_a;
1163         const struct object_entry *b = *(struct object_entry **)_b;
1164
1165         if (a->type > b->type)
1166                 return -1;
1167         if (a->type < b->type)
1168                 return 1;
1169         if (a->hash > b->hash)
1170                 return -1;
1171         if (a->hash < b->hash)
1172                 return 1;
1173         if (a->preferred_base > b->preferred_base)
1174                 return -1;
1175         if (a->preferred_base < b->preferred_base)
1176                 return 1;
1177         if (a->size > b->size)
1178                 return -1;
1179         if (a->size < b->size)
1180                 return 1;
1181         return a < b ? -1 : (a > b);  /* newest first */
1182 }
1183
1184 struct unpacked {
1185         struct object_entry *entry;
1186         void *data;
1187         struct delta_index *index;
1188         unsigned depth;
1189 };
1190
1191 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1192                            unsigned long delta_size)
1193 {
1194         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1195                 return 0;
1196
1197         if (delta_size < cache_max_small_delta_size)
1198                 return 1;
1199
1200         /* cache delta, if objects are large enough compared to delta size */
1201         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1202                 return 1;
1203
1204         return 0;
1205 }
1206
1207 #ifndef NO_PTHREADS
1208
1209 static pthread_mutex_t read_mutex;
1210 #define read_lock()             pthread_mutex_lock(&read_mutex)
1211 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1212
1213 static pthread_mutex_t cache_mutex;
1214 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1215 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1216
1217 static pthread_mutex_t progress_mutex;
1218 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1219 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1220
1221 #else
1222
1223 #define read_lock()             (void)0
1224 #define read_unlock()           (void)0
1225 #define cache_lock()            (void)0
1226 #define cache_unlock()          (void)0
1227 #define progress_lock()         (void)0
1228 #define progress_unlock()       (void)0
1229
1230 #endif
1231
1232 static int try_delta(struct unpacked *trg, struct unpacked *src,
1233                      unsigned max_depth, unsigned long *mem_usage)
1234 {
1235         struct object_entry *trg_entry = trg->entry;
1236         struct object_entry *src_entry = src->entry;
1237         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1238         unsigned ref_depth;
1239         enum object_type type;
1240         void *delta_buf;
1241
1242         /* Don't bother doing diffs between different types */
1243         if (trg_entry->type != src_entry->type)
1244                 return -1;
1245
1246         /*
1247          * We do not bother to try a delta that we discarded
1248          * on an earlier try, but only when reusing delta data.
1249          */
1250         if (reuse_delta && trg_entry->in_pack &&
1251             trg_entry->in_pack == src_entry->in_pack &&
1252             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1253             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1254                 return 0;
1255
1256         /* Let's not bust the allowed depth. */
1257         if (src->depth >= max_depth)
1258                 return 0;
1259
1260         /* Now some size filtering heuristics. */
1261         trg_size = trg_entry->size;
1262         if (!trg_entry->delta) {
1263                 max_size = trg_size/2 - 20;
1264                 ref_depth = 1;
1265         } else {
1266                 max_size = trg_entry->delta_size;
1267                 ref_depth = trg->depth;
1268         }
1269         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1270                                                 (max_depth - ref_depth + 1);
1271         if (max_size == 0)
1272                 return 0;
1273         src_size = src_entry->size;
1274         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1275         if (sizediff >= max_size)
1276                 return 0;
1277         if (trg_size < src_size / 32)
1278                 return 0;
1279
1280         /* Load data if not already done */
1281         if (!trg->data) {
1282                 read_lock();
1283                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1284                 read_unlock();
1285                 if (!trg->data)
1286                         die("object %s cannot be read",
1287                             sha1_to_hex(trg_entry->idx.sha1));
1288                 if (sz != trg_size)
1289                         die("object %s inconsistent object length (%lu vs %lu)",
1290                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1291                 *mem_usage += sz;
1292         }
1293         if (!src->data) {
1294                 read_lock();
1295                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1296                 read_unlock();
1297                 if (!src->data) {
1298                         if (src_entry->preferred_base) {
1299                                 static int warned = 0;
1300                                 if (!warned++)
1301                                         warning("object %s cannot be read",
1302                                                 sha1_to_hex(src_entry->idx.sha1));
1303                                 /*
1304                                  * Those objects are not included in the
1305                                  * resulting pack.  Be resilient and ignore
1306                                  * them if they can't be read, in case the
1307                                  * pack could be created nevertheless.
1308                                  */
1309                                 return 0;
1310                         }
1311                         die("object %s cannot be read",
1312                             sha1_to_hex(src_entry->idx.sha1));
1313                 }
1314                 if (sz != src_size)
1315                         die("object %s inconsistent object length (%lu vs %lu)",
1316                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1317                 *mem_usage += sz;
1318         }
1319         if (!src->index) {
1320                 src->index = create_delta_index(src->data, src_size);
1321                 if (!src->index) {
1322                         static int warned = 0;
1323                         if (!warned++)
1324                                 warning("suboptimal pack - out of memory");
1325                         return 0;
1326                 }
1327                 *mem_usage += sizeof_delta_index(src->index);
1328         }
1329
1330         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1331         if (!delta_buf)
1332                 return 0;
1333
1334         if (trg_entry->delta) {
1335                 /* Prefer only shallower same-sized deltas. */
1336                 if (delta_size == trg_entry->delta_size &&
1337                     src->depth + 1 >= trg->depth) {
1338                         free(delta_buf);
1339                         return 0;
1340                 }
1341         }
1342
1343         /*
1344          * Handle memory allocation outside of the cache
1345          * accounting lock.  Compiler will optimize the strangeness
1346          * away when NO_PTHREADS is defined.
1347          */
1348         free(trg_entry->delta_data);
1349         cache_lock();
1350         if (trg_entry->delta_data) {
1351                 delta_cache_size -= trg_entry->delta_size;
1352                 trg_entry->delta_data = NULL;
1353         }
1354         if (delta_cacheable(src_size, trg_size, delta_size)) {
1355                 delta_cache_size += delta_size;
1356                 cache_unlock();
1357                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1358         } else {
1359                 cache_unlock();
1360                 free(delta_buf);
1361         }
1362
1363         trg_entry->delta = src_entry;
1364         trg_entry->delta_size = delta_size;
1365         trg->depth = src->depth + 1;
1366
1367         return 1;
1368 }
1369
1370 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1371 {
1372         struct object_entry *child = me->delta_child;
1373         unsigned int m = n;
1374         while (child) {
1375                 unsigned int c = check_delta_limit(child, n + 1);
1376                 if (m < c)
1377                         m = c;
1378                 child = child->delta_sibling;
1379         }
1380         return m;
1381 }
1382
1383 static unsigned long free_unpacked(struct unpacked *n)
1384 {
1385         unsigned long freed_mem = sizeof_delta_index(n->index);
1386         free_delta_index(n->index);
1387         n->index = NULL;
1388         if (n->data) {
1389                 freed_mem += n->entry->size;
1390                 free(n->data);
1391                 n->data = NULL;
1392         }
1393         n->entry = NULL;
1394         n->depth = 0;
1395         return freed_mem;
1396 }
1397
1398 static void find_deltas(struct object_entry **list, unsigned *list_size,
1399                         int window, int depth, unsigned *processed)
1400 {
1401         uint32_t i, idx = 0, count = 0;
1402         struct unpacked *array;
1403         unsigned long mem_usage = 0;
1404
1405         array = xcalloc(window, sizeof(struct unpacked));
1406
1407         for (;;) {
1408                 struct object_entry *entry;
1409                 struct unpacked *n = array + idx;
1410                 int j, max_depth, best_base = -1;
1411
1412                 progress_lock();
1413                 if (!*list_size) {
1414                         progress_unlock();
1415                         break;
1416                 }
1417                 entry = *list++;
1418                 (*list_size)--;
1419                 if (!entry->preferred_base) {
1420                         (*processed)++;
1421                         display_progress(progress_state, *processed);
1422                 }
1423                 progress_unlock();
1424
1425                 mem_usage -= free_unpacked(n);
1426                 n->entry = entry;
1427
1428                 while (window_memory_limit &&
1429                        mem_usage > window_memory_limit &&
1430                        count > 1) {
1431                         uint32_t tail = (idx + window - count) % window;
1432                         mem_usage -= free_unpacked(array + tail);
1433                         count--;
1434                 }
1435
1436                 /* We do not compute delta to *create* objects we are not
1437                  * going to pack.
1438                  */
1439                 if (entry->preferred_base)
1440                         goto next;
1441
1442                 /*
1443                  * If the current object is at pack edge, take the depth the
1444                  * objects that depend on the current object into account
1445                  * otherwise they would become too deep.
1446                  */
1447                 max_depth = depth;
1448                 if (entry->delta_child) {
1449                         max_depth -= check_delta_limit(entry, 0);
1450                         if (max_depth <= 0)
1451                                 goto next;
1452                 }
1453
1454                 j = window;
1455                 while (--j > 0) {
1456                         int ret;
1457                         uint32_t other_idx = idx + j;
1458                         struct unpacked *m;
1459                         if (other_idx >= window)
1460                                 other_idx -= window;
1461                         m = array + other_idx;
1462                         if (!m->entry)
1463                                 break;
1464                         ret = try_delta(n, m, max_depth, &mem_usage);
1465                         if (ret < 0)
1466                                 break;
1467                         else if (ret > 0)
1468                                 best_base = other_idx;
1469                 }
1470
1471                 /*
1472                  * If we decided to cache the delta data, then it is best
1473                  * to compress it right away.  First because we have to do
1474                  * it anyway, and doing it here while we're threaded will
1475                  * save a lot of time in the non threaded write phase,
1476                  * as well as allow for caching more deltas within
1477                  * the same cache size limit.
1478                  * ...
1479                  * But only if not writing to stdout, since in that case
1480                  * the network is most likely throttling writes anyway,
1481                  * and therefore it is best to go to the write phase ASAP
1482                  * instead, as we can afford spending more time compressing
1483                  * between writes at that moment.
1484                  */
1485                 if (entry->delta_data && !pack_to_stdout) {
1486                         entry->z_delta_size = do_compress(&entry->delta_data,
1487                                                           entry->delta_size);
1488                         cache_lock();
1489                         delta_cache_size -= entry->delta_size;
1490                         delta_cache_size += entry->z_delta_size;
1491                         cache_unlock();
1492                 }
1493
1494                 /* if we made n a delta, and if n is already at max
1495                  * depth, leaving it in the window is pointless.  we
1496                  * should evict it first.
1497                  */
1498                 if (entry->delta && max_depth <= n->depth)
1499                         continue;
1500
1501                 /*
1502                  * Move the best delta base up in the window, after the
1503                  * currently deltified object, to keep it longer.  It will
1504                  * be the first base object to be attempted next.
1505                  */
1506                 if (entry->delta) {
1507                         struct unpacked swap = array[best_base];
1508                         int dist = (window + idx - best_base) % window;
1509                         int dst = best_base;
1510                         while (dist--) {
1511                                 int src = (dst + 1) % window;
1512                                 array[dst] = array[src];
1513                                 dst = src;
1514                         }
1515                         array[dst] = swap;
1516                 }
1517
1518                 next:
1519                 idx++;
1520                 if (count + 1 < window)
1521                         count++;
1522                 if (idx >= window)
1523                         idx = 0;
1524         }
1525
1526         for (i = 0; i < window; ++i) {
1527                 free_delta_index(array[i].index);
1528                 free(array[i].data);
1529         }
1530         free(array);
1531 }
1532
1533 #ifndef NO_PTHREADS
1534
1535 static void try_to_free_from_threads(size_t size)
1536 {
1537         read_lock();
1538         release_pack_memory(size, -1);
1539         read_unlock();
1540 }
1541
1542 static try_to_free_t old_try_to_free_routine;
1543
1544 /*
1545  * The main thread waits on the condition that (at least) one of the workers
1546  * has stopped working (which is indicated in the .working member of
1547  * struct thread_params).
1548  * When a work thread has completed its work, it sets .working to 0 and
1549  * signals the main thread and waits on the condition that .data_ready
1550  * becomes 1.
1551  */
1552
1553 struct thread_params {
1554         pthread_t thread;
1555         struct object_entry **list;
1556         unsigned list_size;
1557         unsigned remaining;
1558         int window;
1559         int depth;
1560         int working;
1561         int data_ready;
1562         pthread_mutex_t mutex;
1563         pthread_cond_t cond;
1564         unsigned *processed;
1565 };
1566
1567 static pthread_cond_t progress_cond;
1568
1569 /*
1570  * Mutex and conditional variable can't be statically-initialized on Windows.
1571  */
1572 static void init_threaded_search(void)
1573 {
1574         init_recursive_mutex(&read_mutex);
1575         pthread_mutex_init(&cache_mutex, NULL);
1576         pthread_mutex_init(&progress_mutex, NULL);
1577         pthread_cond_init(&progress_cond, NULL);
1578         old_try_to_free_routine = set_try_to_free_routine(try_to_free_from_threads);
1579 }
1580
1581 static void cleanup_threaded_search(void)
1582 {
1583         set_try_to_free_routine(old_try_to_free_routine);
1584         pthread_cond_destroy(&progress_cond);
1585         pthread_mutex_destroy(&read_mutex);
1586         pthread_mutex_destroy(&cache_mutex);
1587         pthread_mutex_destroy(&progress_mutex);
1588 }
1589
1590 static void *threaded_find_deltas(void *arg)
1591 {
1592         struct thread_params *me = arg;
1593
1594         while (me->remaining) {
1595                 find_deltas(me->list, &me->remaining,
1596                             me->window, me->depth, me->processed);
1597
1598                 progress_lock();
1599                 me->working = 0;
1600                 pthread_cond_signal(&progress_cond);
1601                 progress_unlock();
1602
1603                 /*
1604                  * We must not set ->data_ready before we wait on the
1605                  * condition because the main thread may have set it to 1
1606                  * before we get here. In order to be sure that new
1607                  * work is available if we see 1 in ->data_ready, it
1608                  * was initialized to 0 before this thread was spawned
1609                  * and we reset it to 0 right away.
1610                  */
1611                 pthread_mutex_lock(&me->mutex);
1612                 while (!me->data_ready)
1613                         pthread_cond_wait(&me->cond, &me->mutex);
1614                 me->data_ready = 0;
1615                 pthread_mutex_unlock(&me->mutex);
1616         }
1617         /* leave ->working 1 so that this doesn't get more work assigned */
1618         return NULL;
1619 }
1620
1621 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1622                            int window, int depth, unsigned *processed)
1623 {
1624         struct thread_params *p;
1625         int i, ret, active_threads = 0;
1626
1627         init_threaded_search();
1628
1629         if (!delta_search_threads)      /* --threads=0 means autodetect */
1630                 delta_search_threads = online_cpus();
1631         if (delta_search_threads <= 1) {
1632                 find_deltas(list, &list_size, window, depth, processed);
1633                 cleanup_threaded_search();
1634                 return;
1635         }
1636         if (progress > pack_to_stdout)
1637                 fprintf(stderr, "Delta compression using up to %d threads.\n",
1638                                 delta_search_threads);
1639         p = xcalloc(delta_search_threads, sizeof(*p));
1640
1641         /* Partition the work amongst work threads. */
1642         for (i = 0; i < delta_search_threads; i++) {
1643                 unsigned sub_size = list_size / (delta_search_threads - i);
1644
1645                 /* don't use too small segments or no deltas will be found */
1646                 if (sub_size < 2*window && i+1 < delta_search_threads)
1647                         sub_size = 0;
1648
1649                 p[i].window = window;
1650                 p[i].depth = depth;
1651                 p[i].processed = processed;
1652                 p[i].working = 1;
1653                 p[i].data_ready = 0;
1654
1655                 /* try to split chunks on "path" boundaries */
1656                 while (sub_size && sub_size < list_size &&
1657                        list[sub_size]->hash &&
1658                        list[sub_size]->hash == list[sub_size-1]->hash)
1659                         sub_size++;
1660
1661                 p[i].list = list;
1662                 p[i].list_size = sub_size;
1663                 p[i].remaining = sub_size;
1664
1665                 list += sub_size;
1666                 list_size -= sub_size;
1667         }
1668
1669         /* Start work threads. */
1670         for (i = 0; i < delta_search_threads; i++) {
1671                 if (!p[i].list_size)
1672                         continue;
1673                 pthread_mutex_init(&p[i].mutex, NULL);
1674                 pthread_cond_init(&p[i].cond, NULL);
1675                 ret = pthread_create(&p[i].thread, NULL,
1676                                      threaded_find_deltas, &p[i]);
1677                 if (ret)
1678                         die("unable to create thread: %s", strerror(ret));
1679                 active_threads++;
1680         }
1681
1682         /*
1683          * Now let's wait for work completion.  Each time a thread is done
1684          * with its work, we steal half of the remaining work from the
1685          * thread with the largest number of unprocessed objects and give
1686          * it to that newly idle thread.  This ensure good load balancing
1687          * until the remaining object list segments are simply too short
1688          * to be worth splitting anymore.
1689          */
1690         while (active_threads) {
1691                 struct thread_params *target = NULL;
1692                 struct thread_params *victim = NULL;
1693                 unsigned sub_size = 0;
1694
1695                 progress_lock();
1696                 for (;;) {
1697                         for (i = 0; !target && i < delta_search_threads; i++)
1698                                 if (!p[i].working)
1699                                         target = &p[i];
1700                         if (target)
1701                                 break;
1702                         pthread_cond_wait(&progress_cond, &progress_mutex);
1703                 }
1704
1705                 for (i = 0; i < delta_search_threads; i++)
1706                         if (p[i].remaining > 2*window &&
1707                             (!victim || victim->remaining < p[i].remaining))
1708                                 victim = &p[i];
1709                 if (victim) {
1710                         sub_size = victim->remaining / 2;
1711                         list = victim->list + victim->list_size - sub_size;
1712                         while (sub_size && list[0]->hash &&
1713                                list[0]->hash == list[-1]->hash) {
1714                                 list++;
1715                                 sub_size--;
1716                         }
1717                         if (!sub_size) {
1718                                 /*
1719                                  * It is possible for some "paths" to have
1720                                  * so many objects that no hash boundary
1721                                  * might be found.  Let's just steal the
1722                                  * exact half in that case.
1723                                  */
1724                                 sub_size = victim->remaining / 2;
1725                                 list -= sub_size;
1726                         }
1727                         target->list = list;
1728                         victim->list_size -= sub_size;
1729                         victim->remaining -= sub_size;
1730                 }
1731                 target->list_size = sub_size;
1732                 target->remaining = sub_size;
1733                 target->working = 1;
1734                 progress_unlock();
1735
1736                 pthread_mutex_lock(&target->mutex);
1737                 target->data_ready = 1;
1738                 pthread_cond_signal(&target->cond);
1739                 pthread_mutex_unlock(&target->mutex);
1740
1741                 if (!sub_size) {
1742                         pthread_join(target->thread, NULL);
1743                         pthread_cond_destroy(&target->cond);
1744                         pthread_mutex_destroy(&target->mutex);
1745                         active_threads--;
1746                 }
1747         }
1748         cleanup_threaded_search();
1749         free(p);
1750 }
1751
1752 #else
1753 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1754 #endif
1755
1756 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1757 {
1758         unsigned char peeled[20];
1759
1760         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1761             !peel_ref(path, peeled)        && /* peelable? */
1762             !is_null_sha1(peeled)          && /* annotated tag? */
1763             locate_object_entry(peeled))      /* object packed? */
1764                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1765         return 0;
1766 }
1767
1768 static void prepare_pack(int window, int depth)
1769 {
1770         struct object_entry **delta_list;
1771         uint32_t i, nr_deltas;
1772         unsigned n;
1773
1774         get_object_details();
1775
1776         /*
1777          * If we're locally repacking then we need to be doubly careful
1778          * from now on in order to make sure no stealth corruption gets
1779          * propagated to the new pack.  Clients receiving streamed packs
1780          * should validate everything they get anyway so no need to incur
1781          * the additional cost here in that case.
1782          */
1783         if (!pack_to_stdout)
1784                 do_check_packed_object_crc = 1;
1785
1786         if (!nr_objects || !window || !depth)
1787                 return;
1788
1789         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1790         nr_deltas = n = 0;
1791
1792         for (i = 0; i < nr_objects; i++) {
1793                 struct object_entry *entry = objects + i;
1794
1795                 if (entry->delta)
1796                         /* This happens if we decided to reuse existing
1797                          * delta from a pack.  "reuse_delta &&" is implied.
1798                          */
1799                         continue;
1800
1801                 if (entry->size < 50)
1802                         continue;
1803
1804                 if (entry->no_try_delta)
1805                         continue;
1806
1807                 if (!entry->preferred_base) {
1808                         nr_deltas++;
1809                         if (entry->type < 0)
1810                                 die("unable to get type of object %s",
1811                                     sha1_to_hex(entry->idx.sha1));
1812                 } else {
1813                         if (entry->type < 0) {
1814                                 /*
1815                                  * This object is not found, but we
1816                                  * don't have to include it anyway.
1817                                  */
1818                                 continue;
1819                         }
1820                 }
1821
1822                 delta_list[n++] = entry;
1823         }
1824
1825         if (nr_deltas && n > 1) {
1826                 unsigned nr_done = 0;
1827                 if (progress)
1828                         progress_state = start_progress("Compressing objects",
1829                                                         nr_deltas);
1830                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1831                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1832                 stop_progress(&progress_state);
1833                 if (nr_done != nr_deltas)
1834                         die("inconsistency with delta count");
1835         }
1836         free(delta_list);
1837 }
1838
1839 static int git_pack_config(const char *k, const char *v, void *cb)
1840 {
1841         if (!strcmp(k, "pack.window")) {
1842                 window = git_config_int(k, v);
1843                 return 0;
1844         }
1845         if (!strcmp(k, "pack.windowmemory")) {
1846                 window_memory_limit = git_config_ulong(k, v);
1847                 return 0;
1848         }
1849         if (!strcmp(k, "pack.depth")) {
1850                 depth = git_config_int(k, v);
1851                 return 0;
1852         }
1853         if (!strcmp(k, "pack.compression")) {
1854                 int level = git_config_int(k, v);
1855                 if (level == -1)
1856                         level = Z_DEFAULT_COMPRESSION;
1857                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1858                         die("bad pack compression level %d", level);
1859                 pack_compression_level = level;
1860                 pack_compression_seen = 1;
1861                 return 0;
1862         }
1863         if (!strcmp(k, "pack.deltacachesize")) {
1864                 max_delta_cache_size = git_config_int(k, v);
1865                 return 0;
1866         }
1867         if (!strcmp(k, "pack.deltacachelimit")) {
1868                 cache_max_small_delta_size = git_config_int(k, v);
1869                 return 0;
1870         }
1871         if (!strcmp(k, "pack.threads")) {
1872                 delta_search_threads = git_config_int(k, v);
1873                 if (delta_search_threads < 0)
1874                         die("invalid number of threads specified (%d)",
1875                             delta_search_threads);
1876 #ifdef NO_PTHREADS
1877                 if (delta_search_threads != 1)
1878                         warning("no threads support, ignoring %s", k);
1879 #endif
1880                 return 0;
1881         }
1882         if (!strcmp(k, "pack.indexversion")) {
1883                 pack_idx_default_version = git_config_int(k, v);
1884                 if (pack_idx_default_version > 2)
1885                         die("bad pack.indexversion=%"PRIu32,
1886                                 pack_idx_default_version);
1887                 return 0;
1888         }
1889         if (!strcmp(k, "pack.packsizelimit")) {
1890                 pack_size_limit_cfg = git_config_ulong(k, v);
1891                 return 0;
1892         }
1893         return git_default_config(k, v, cb);
1894 }
1895
1896 static void read_object_list_from_stdin(void)
1897 {
1898         char line[40 + 1 + PATH_MAX + 2];
1899         unsigned char sha1[20];
1900
1901         for (;;) {
1902                 if (!fgets(line, sizeof(line), stdin)) {
1903                         if (feof(stdin))
1904                                 break;
1905                         if (!ferror(stdin))
1906                                 die("fgets returned NULL, not EOF, not error!");
1907                         if (errno != EINTR)
1908                                 die_errno("fgets");
1909                         clearerr(stdin);
1910                         continue;
1911                 }
1912                 if (line[0] == '-') {
1913                         if (get_sha1_hex(line+1, sha1))
1914                                 die("expected edge sha1, got garbage:\n %s",
1915                                     line);
1916                         add_preferred_base(sha1);
1917                         continue;
1918                 }
1919                 if (get_sha1_hex(line, sha1))
1920                         die("expected sha1, got garbage:\n %s", line);
1921
1922                 add_preferred_base_object(line+41);
1923                 add_object_entry(sha1, 0, line+41, 0);
1924         }
1925 }
1926
1927 #define OBJECT_ADDED (1u<<20)
1928
1929 static void show_commit(struct commit *commit, void *data)
1930 {
1931         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1932         commit->object.flags |= OBJECT_ADDED;
1933 }
1934
1935 static void show_object(struct object *obj, const struct name_path *path, const char *last)
1936 {
1937         char *name = path_name(path, last);
1938
1939         add_preferred_base_object(name);
1940         add_object_entry(obj->sha1, obj->type, name, 0);
1941         obj->flags |= OBJECT_ADDED;
1942
1943         /*
1944          * We will have generated the hash from the name,
1945          * but not saved a pointer to it - we can free it
1946          */
1947         free((char *)name);
1948 }
1949
1950 static void show_edge(struct commit *commit)
1951 {
1952         add_preferred_base(commit->object.sha1);
1953 }
1954
1955 struct in_pack_object {
1956         off_t offset;
1957         struct object *object;
1958 };
1959
1960 struct in_pack {
1961         int alloc;
1962         int nr;
1963         struct in_pack_object *array;
1964 };
1965
1966 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1967 {
1968         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1969         in_pack->array[in_pack->nr].object = object;
1970         in_pack->nr++;
1971 }
1972
1973 /*
1974  * Compare the objects in the offset order, in order to emulate the
1975  * "git rev-list --objects" output that produced the pack originally.
1976  */
1977 static int ofscmp(const void *a_, const void *b_)
1978 {
1979         struct in_pack_object *a = (struct in_pack_object *)a_;
1980         struct in_pack_object *b = (struct in_pack_object *)b_;
1981
1982         if (a->offset < b->offset)
1983                 return -1;
1984         else if (a->offset > b->offset)
1985                 return 1;
1986         else
1987                 return hashcmp(a->object->sha1, b->object->sha1);
1988 }
1989
1990 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1991 {
1992         struct packed_git *p;
1993         struct in_pack in_pack;
1994         uint32_t i;
1995
1996         memset(&in_pack, 0, sizeof(in_pack));
1997
1998         for (p = packed_git; p; p = p->next) {
1999                 const unsigned char *sha1;
2000                 struct object *o;
2001
2002                 if (!p->pack_local || p->pack_keep)
2003                         continue;
2004                 if (open_pack_index(p))
2005                         die("cannot open pack index");
2006
2007                 ALLOC_GROW(in_pack.array,
2008                            in_pack.nr + p->num_objects,
2009                            in_pack.alloc);
2010
2011                 for (i = 0; i < p->num_objects; i++) {
2012                         sha1 = nth_packed_object_sha1(p, i);
2013                         o = lookup_unknown_object(sha1);
2014                         if (!(o->flags & OBJECT_ADDED))
2015                                 mark_in_pack_object(o, p, &in_pack);
2016                         o->flags |= OBJECT_ADDED;
2017                 }
2018         }
2019
2020         if (in_pack.nr) {
2021                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
2022                       ofscmp);
2023                 for (i = 0; i < in_pack.nr; i++) {
2024                         struct object *o = in_pack.array[i].object;
2025                         add_object_entry(o->sha1, o->type, "", 0);
2026                 }
2027         }
2028         free(in_pack.array);
2029 }
2030
2031 static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2032 {
2033         static struct packed_git *last_found = (void *)1;
2034         struct packed_git *p;
2035
2036         p = (last_found != (void *)1) ? last_found : packed_git;
2037
2038         while (p) {
2039                 if ((!p->pack_local || p->pack_keep) &&
2040                         find_pack_entry_one(sha1, p)) {
2041                         last_found = p;
2042                         return 1;
2043                 }
2044                 if (p == last_found)
2045                         p = packed_git;
2046                 else
2047                         p = p->next;
2048                 if (p == last_found)
2049                         p = p->next;
2050         }
2051         return 0;
2052 }
2053
2054 static void loosen_unused_packed_objects(struct rev_info *revs)
2055 {
2056         struct packed_git *p;
2057         uint32_t i;
2058         const unsigned char *sha1;
2059
2060         for (p = packed_git; p; p = p->next) {
2061                 if (!p->pack_local || p->pack_keep)
2062                         continue;
2063
2064                 if (open_pack_index(p))
2065                         die("cannot open pack index");
2066
2067                 for (i = 0; i < p->num_objects; i++) {
2068                         sha1 = nth_packed_object_sha1(p, i);
2069                         if (!locate_object_entry(sha1) &&
2070                                 !has_sha1_pack_kept_or_nonlocal(sha1))
2071                                 if (force_object_loose(sha1, p->mtime))
2072                                         die("unable to force loose object");
2073                 }
2074         }
2075 }
2076
2077 static void get_object_list(int ac, const char **av)
2078 {
2079         struct rev_info revs;
2080         char line[1000];
2081         int flags = 0;
2082
2083         init_revisions(&revs, NULL);
2084         save_commit_buffer = 0;
2085         setup_revisions(ac, av, &revs, NULL);
2086
2087         while (fgets(line, sizeof(line), stdin) != NULL) {
2088                 int len = strlen(line);
2089                 if (len && line[len - 1] == '\n')
2090                         line[--len] = 0;
2091                 if (!len)
2092                         break;
2093                 if (*line == '-') {
2094                         if (!strcmp(line, "--not")) {
2095                                 flags ^= UNINTERESTING;
2096                                 continue;
2097                         }
2098                         die("not a rev '%s'", line);
2099                 }
2100                 if (handle_revision_arg(line, &revs, flags, 1))
2101                         die("bad revision '%s'", line);
2102         }
2103
2104         if (prepare_revision_walk(&revs))
2105                 die("revision walk setup failed");
2106         mark_edges_uninteresting(revs.commits, &revs, show_edge);
2107         traverse_commit_list(&revs, show_commit, show_object, NULL);
2108
2109         if (keep_unreachable)
2110                 add_objects_in_unpacked_packs(&revs);
2111         if (unpack_unreachable)
2112                 loosen_unused_packed_objects(&revs);
2113 }
2114
2115 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2116 {
2117         int use_internal_rev_list = 0;
2118         int thin = 0;
2119         int all_progress_implied = 0;
2120         uint32_t i;
2121         const char **rp_av;
2122         int rp_ac_alloc = 64;
2123         int rp_ac;
2124
2125         read_replace_refs = 0;
2126
2127         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2128
2129         rp_av[0] = "pack-objects";
2130         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2131         rp_ac = 2;
2132
2133         git_config(git_pack_config, NULL);
2134         if (!pack_compression_seen && core_compression_seen)
2135                 pack_compression_level = core_compression_level;
2136
2137         progress = isatty(2);
2138         for (i = 1; i < argc; i++) {
2139                 const char *arg = argv[i];
2140
2141                 if (*arg != '-')
2142                         break;
2143
2144                 if (!strcmp("--non-empty", arg)) {
2145                         non_empty = 1;
2146                         continue;
2147                 }
2148                 if (!strcmp("--local", arg)) {
2149                         local = 1;
2150                         continue;
2151                 }
2152                 if (!strcmp("--incremental", arg)) {
2153                         incremental = 1;
2154                         continue;
2155                 }
2156                 if (!strcmp("--honor-pack-keep", arg)) {
2157                         ignore_packed_keep = 1;
2158                         continue;
2159                 }
2160                 if (!prefixcmp(arg, "--compression=")) {
2161                         char *end;
2162                         int level = strtoul(arg+14, &end, 0);
2163                         if (!arg[14] || *end)
2164                                 usage(pack_usage);
2165                         if (level == -1)
2166                                 level = Z_DEFAULT_COMPRESSION;
2167                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2168                                 die("bad pack compression level %d", level);
2169                         pack_compression_level = level;
2170                         continue;
2171                 }
2172                 if (!prefixcmp(arg, "--max-pack-size=")) {
2173                         pack_size_limit_cfg = 0;
2174                         if (!git_parse_ulong(arg+16, &pack_size_limit))
2175                                 usage(pack_usage);
2176                         continue;
2177                 }
2178                 if (!prefixcmp(arg, "--window=")) {
2179                         char *end;
2180                         window = strtoul(arg+9, &end, 0);
2181                         if (!arg[9] || *end)
2182                                 usage(pack_usage);
2183                         continue;
2184                 }
2185                 if (!prefixcmp(arg, "--window-memory=")) {
2186                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2187                                 usage(pack_usage);
2188                         continue;
2189                 }
2190                 if (!prefixcmp(arg, "--threads=")) {
2191                         char *end;
2192                         delta_search_threads = strtoul(arg+10, &end, 0);
2193                         if (!arg[10] || *end || delta_search_threads < 0)
2194                                 usage(pack_usage);
2195 #ifdef NO_PTHREADS
2196                         if (delta_search_threads != 1)
2197                                 warning("no threads support, "
2198                                         "ignoring %s", arg);
2199 #endif
2200                         continue;
2201                 }
2202                 if (!prefixcmp(arg, "--depth=")) {
2203                         char *end;
2204                         depth = strtoul(arg+8, &end, 0);
2205                         if (!arg[8] || *end)
2206                                 usage(pack_usage);
2207                         continue;
2208                 }
2209                 if (!strcmp("--progress", arg)) {
2210                         progress = 1;
2211                         continue;
2212                 }
2213                 if (!strcmp("--all-progress", arg)) {
2214                         progress = 2;
2215                         continue;
2216                 }
2217                 if (!strcmp("--all-progress-implied", arg)) {
2218                         all_progress_implied = 1;
2219                         continue;
2220                 }
2221                 if (!strcmp("-q", arg)) {
2222                         progress = 0;
2223                         continue;
2224                 }
2225                 if (!strcmp("--no-reuse-delta", arg)) {
2226                         reuse_delta = 0;
2227                         continue;
2228                 }
2229                 if (!strcmp("--no-reuse-object", arg)) {
2230                         reuse_object = reuse_delta = 0;
2231                         continue;
2232                 }
2233                 if (!strcmp("--delta-base-offset", arg)) {
2234                         allow_ofs_delta = 1;
2235                         continue;
2236                 }
2237                 if (!strcmp("--stdout", arg)) {
2238                         pack_to_stdout = 1;
2239                         continue;
2240                 }
2241                 if (!strcmp("--revs", arg)) {
2242                         use_internal_rev_list = 1;
2243                         continue;
2244                 }
2245                 if (!strcmp("--keep-unreachable", arg)) {
2246                         keep_unreachable = 1;
2247                         continue;
2248                 }
2249                 if (!strcmp("--unpack-unreachable", arg)) {
2250                         unpack_unreachable = 1;
2251                         continue;
2252                 }
2253                 if (!strcmp("--include-tag", arg)) {
2254                         include_tag = 1;
2255                         continue;
2256                 }
2257                 if (!strcmp("--unpacked", arg) ||
2258                     !strcmp("--reflog", arg) ||
2259                     !strcmp("--all", arg)) {
2260                         use_internal_rev_list = 1;
2261                         if (rp_ac >= rp_ac_alloc - 1) {
2262                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2263                                 rp_av = xrealloc(rp_av,
2264                                                  rp_ac_alloc * sizeof(*rp_av));
2265                         }
2266                         rp_av[rp_ac++] = arg;
2267                         continue;
2268                 }
2269                 if (!strcmp("--thin", arg)) {
2270                         use_internal_rev_list = 1;
2271                         thin = 1;
2272                         rp_av[1] = "--objects-edge";
2273                         continue;
2274                 }
2275                 if (!prefixcmp(arg, "--index-version=")) {
2276                         char *c;
2277                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2278                         if (pack_idx_default_version > 2)
2279                                 die("bad %s", arg);
2280                         if (*c == ',')
2281                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2282                         if (*c || pack_idx_off32_limit & 0x80000000)
2283                                 die("bad %s", arg);
2284                         continue;
2285                 }
2286                 if (!strcmp(arg, "--keep-true-parents")) {
2287                         grafts_replace_parents = 0;
2288                         continue;
2289                 }
2290                 usage(pack_usage);
2291         }
2292
2293         /* Traditionally "pack-objects [options] base extra" failed;
2294          * we would however want to take refs parameter that would
2295          * have been given to upstream rev-list ourselves, which means
2296          * we somehow want to say what the base name is.  So the
2297          * syntax would be:
2298          *
2299          * pack-objects [options] base <refs...>
2300          *
2301          * in other words, we would treat the first non-option as the
2302          * base_name and send everything else to the internal revision
2303          * walker.
2304          */
2305
2306         if (!pack_to_stdout)
2307                 base_name = argv[i++];
2308
2309         if (pack_to_stdout != !base_name)
2310                 usage(pack_usage);
2311
2312         if (!pack_to_stdout && !pack_size_limit)
2313                 pack_size_limit = pack_size_limit_cfg;
2314         if (pack_to_stdout && pack_size_limit)
2315                 die("--max-pack-size cannot be used to build a pack for transfer.");
2316         if (pack_size_limit && pack_size_limit < 1024*1024) {
2317                 warning("minimum pack size limit is 1 MiB");
2318                 pack_size_limit = 1024*1024;
2319         }
2320
2321         if (!pack_to_stdout && thin)
2322                 die("--thin cannot be used to build an indexable pack.");
2323
2324         if (keep_unreachable && unpack_unreachable)
2325                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2326
2327         if (progress && all_progress_implied)
2328                 progress = 2;
2329
2330         prepare_packed_git();
2331
2332         if (progress)
2333                 progress_state = start_progress("Counting objects", 0);
2334         if (!use_internal_rev_list)
2335                 read_object_list_from_stdin();
2336         else {
2337                 rp_av[rp_ac] = NULL;
2338                 get_object_list(rp_ac, rp_av);
2339         }
2340         cleanup_preferred_base();
2341         if (include_tag && nr_result)
2342                 for_each_ref(add_ref_tag, NULL);
2343         stop_progress(&progress_state);
2344
2345         if (non_empty && !nr_result)
2346                 return 0;
2347         if (nr_result)
2348                 prepare_pack(window, depth);
2349         write_pack_file();
2350         if (progress)
2351                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2352                         " reused %"PRIu32" (delta %"PRIu32")\n",
2353                         written, written_delta, reused, reused_delta);
2354         return 0;
2355 }