git.oblomov.eu Git - git/blob - builtin/pack-objects.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "attr.h"
   4 #include "object.h"
   5 #include "blob.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "tree.h"
   9 #include "delta.h"
  10 #include "pack.h"
  11 #include "pack-revindex.h"
  12 #include "csum-file.h"
  13 #include "tree-walk.h"
  14 #include "diff.h"
  15 #include "revision.h"
  16 #include "list-objects.h"
  17 #include "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 struct pack_idx_option pack_idx_opts;
  74 static const char *base_name;
  75 static int progress = 1;
  76 static int window = 10;
  77 static unsigned long pack_size_limit, pack_size_limit_cfg;
  78 static int depth = 50;
  79 static int delta_search_threads;
  80 static int pack_to_stdout;
  81 static int num_preferred_base;
  82 static struct progress *progress_state;
  83 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  84 static int pack_compression_seen;
  85
  86 static unsigned long delta_cache_size = 0;
  87 static unsigned long max_delta_cache_size = 256 * 1024 * 1024;
  88 static unsigned long cache_max_small_delta_size = 1000;
  89
  90 static unsigned long window_memory_limit = 0;
  91
  92 /*
  93  * The object names in objects array are hashed with this hashtable,
  94  * to help looking up the entry by object name.
  95  * This hashtable is built after all the objects are seen.
  96  */
  97 static int *object_ix;
  98 static int object_ix_hashsz;
  99
 100 /*
 101  * stats
 102  */
 103 static uint32_t written, written_delta;
 104 static uint32_t reused, reused_delta;
 105
 106
 107 static void *get_delta(struct object_entry *entry)
 108 {
 109         unsigned long size, base_size, delta_size;
 110         void *buf, *base_buf, *delta_buf;
 111         enum object_type type;
 112
 113         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 114         if (!buf)
 115                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 116         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
 117         if (!base_buf)
 118                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 119         delta_buf = diff_delta(base_buf, base_size,
 120                                buf, size, &delta_size, 0);
 121         if (!delta_buf || delta_size != entry->delta_size)
 122                 die("delta size changed");
 123         free(buf);
 124         free(base_buf);
 125         return delta_buf;
 126 }
 127
 128 static unsigned long do_compress(void **pptr, unsigned long size)
 129 {
 130         z_stream stream;
 131         void *in, *out;
 132         unsigned long maxsize;
 133
 134         memset(&stream, 0, sizeof(stream));
 135         deflateInit(&stream, pack_compression_level);
 136         maxsize = deflateBound(&stream, size);
 137
 138         in = *pptr;
 139         out = xmalloc(maxsize);
 140         *pptr = out;
 141
 142         stream.next_in = in;
 143         stream.avail_in = size;
 144         stream.next_out = out;
 145         stream.avail_out = maxsize;
 146         while (deflate(&stream, Z_FINISH) == Z_OK)
 147                 ; /* nothing */
 148         deflateEnd(&stream);
 149
 150         free(in);
 151         return stream.total_out;
 152 }
 153
 154 /*
 155  * we are going to reuse the existing object data as is.  make
 156  * sure it is not corrupt.
 157  */
 158 static int check_pack_inflate(struct packed_git *p,
 159                 struct pack_window **w_curs,
 160                 off_t offset,
 161                 off_t len,
 162                 unsigned long expect)
 163 {
 164         z_stream stream;
 165         unsigned char fakebuf[4096], *in;
 166         int st;
 167
 168         memset(&stream, 0, sizeof(stream));
 169         git_inflate_init(&stream);
 170         do {
 171                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 172                 stream.next_in = in;
 173                 stream.next_out = fakebuf;
 174                 stream.avail_out = sizeof(fakebuf);
 175                 st = git_inflate(&stream, Z_FINISH);
 176                 offset += stream.next_in - in;
 177         } while (st == Z_OK || st == Z_BUF_ERROR);
 178         git_inflate_end(&stream);
 179         return (st == Z_STREAM_END &&
 180                 stream.total_out == expect &&
 181                 stream.total_in == len) ? 0 : -1;
 182 }
 183
 184 static void copy_pack_data(struct sha1file *f,
 185                 struct packed_git *p,
 186                 struct pack_window **w_curs,
 187                 off_t offset,
 188                 off_t len)
 189 {
 190         unsigned char *in;
 191         unsigned int avail;
 192
 193         while (len) {
 194                 in = use_pack(p, w_curs, offset, &avail);
 195                 if (avail > len)
 196                         avail = (unsigned int)len;
 197                 sha1write(f, in, avail);
 198                 offset += avail;
 199                 len -= avail;
 200         }
 201 }
 202
 203 static unsigned long write_object(struct sha1file *f,
 204                                   struct object_entry *entry,
 205                                   off_t write_offset)
 206 {
 207         unsigned long size, limit, datalen;
 208         void *buf;
 209         unsigned char header[10], dheader[10];
 210         unsigned hdrlen;
 211         enum object_type type;
 212         int usable_delta, to_reuse;
 213
 214         if (!pack_to_stdout)
 215                 crc32_begin(f);
 216
 217         type = entry->type;
 218
 219         /* apply size limit if limited packsize and not first object */
 220         if (!pack_size_limit || !nr_written)
 221                 limit = 0;
 222         else if (pack_size_limit <= write_offset)
 223                 /*
 224                  * the earlier object did not fit the limit; avoid
 225                  * mistaking this with unlimited (i.e. limit = 0).
 226                  */
 227                 limit = 1;
 228         else
 229                 limit = pack_size_limit - write_offset;
 230
 231         if (!entry->delta)
 232                 usable_delta = 0;       /* no delta */
 233         else if (!pack_size_limit)
 234                usable_delta = 1;        /* unlimited packfile */
 235         else if (entry->delta->idx.offset == (off_t)-1)
 236                 usable_delta = 0;       /* base was written to another pack */
 237         else if (entry->delta->idx.offset)
 238                 usable_delta = 1;       /* base already exists in this pack */
 239         else
 240                 usable_delta = 0;       /* base could end up in another pack */
 241
 242         if (!reuse_object)
 243                 to_reuse = 0;   /* explicit */
 244         else if (!entry->in_pack)
 245                 to_reuse = 0;   /* can't reuse what we don't have */
 246         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
 247                                 /* check_object() decided it for us ... */
 248                 to_reuse = usable_delta;
 249                                 /* ... but pack split may override that */
 250         else if (type != entry->in_pack_type)
 251                 to_reuse = 0;   /* pack has delta which is unusable */
 252         else if (entry->delta)
 253                 to_reuse = 0;   /* we want to pack afresh */
 254         else
 255                 to_reuse = 1;   /* we have it in-pack undeltified,
 256                                  * and we do not need to deltify it.
 257                                  */
 258
 259         if (!to_reuse) {
 260                 no_reuse:
 261                 if (!usable_delta) {
 262                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 263                         if (!buf)
 264                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 265                         /*
 266                          * make sure no cached delta data remains from a
 267                          * previous attempt before a pack split occurred.
 268                          */
 269                         free(entry->delta_data);
 270                         entry->delta_data = NULL;
 271                         entry->z_delta_size = 0;
 272                 } else if (entry->delta_data) {
 273                         size = entry->delta_size;
 274                         buf = entry->delta_data;
 275                         entry->delta_data = NULL;
 276                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 277                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 278                 } else {
 279                         buf = get_delta(entry);
 280                         size = entry->delta_size;
 281                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 282                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 283                 }
 284
 285                 if (entry->z_delta_size)
 286                         datalen = entry->z_delta_size;
 287                 else
 288                         datalen = do_compress(&buf, size);
 289
 290                 /*
 291                  * The object header is a byte of 'type' followed by zero or
 292                  * more bytes of length.
 293                  */
 294                 hdrlen = encode_in_pack_object_header(type, size, header);
 295
 296                 if (type == OBJ_OFS_DELTA) {
 297                         /*
 298                          * Deltas with relative base contain an additional
 299                          * encoding of the relative offset for the delta
 300                          * base from this object's position in the pack.
 301                          */
 302                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 303                         unsigned pos = sizeof(dheader) - 1;
 304                         dheader[pos] = ofs & 127;
 305                         while (ofs >>= 7)
 306                                 dheader[--pos] = 128 | (--ofs & 127);
 307                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 308                                 free(buf);
 309                                 return 0;
 310                         }
 311                         sha1write(f, header, hdrlen);
 312                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 313                         hdrlen += sizeof(dheader) - pos;
 314                 } else if (type == OBJ_REF_DELTA) {
 315                         /*
 316                          * Deltas with a base reference contain
 317                          * an additional 20 bytes for the base sha1.
 318                          */
 319                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 320                                 free(buf);
 321                                 return 0;
 322                         }
 323                         sha1write(f, header, hdrlen);
 324                         sha1write(f, entry->delta->idx.sha1, 20);
 325                         hdrlen += 20;
 326                 } else {
 327                         if (limit && hdrlen + datalen + 20 >= limit) {
 328                                 free(buf);
 329                                 return 0;
 330                         }
 331                         sha1write(f, header, hdrlen);
 332                 }
 333                 sha1write(f, buf, datalen);
 334                 free(buf);
 335         }
 336         else {
 337                 struct packed_git *p = entry->in_pack;
 338                 struct pack_window *w_curs = NULL;
 339                 struct revindex_entry *revidx;
 340                 off_t offset;
 341
 342                 if (entry->delta)
 343                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 344                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 345                 hdrlen = encode_in_pack_object_header(type, entry->size, header);
 346
 347                 offset = entry->in_pack_offset;
 348                 revidx = find_pack_revindex(p, offset);
 349                 datalen = revidx[1].offset - offset;
 350                 if (!pack_to_stdout && p->index_version > 1 &&
 351                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 352                         error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 353                         unuse_pack(&w_curs);
 354                         goto no_reuse;
 355                 }
 356
 357                 offset += entry->in_pack_header_size;
 358                 datalen -= entry->in_pack_header_size;
 359                 if (!pack_to_stdout && p->index_version == 1 &&
 360                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
 361                         error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 362                         unuse_pack(&w_curs);
 363                         goto no_reuse;
 364                 }
 365
 366                 if (type == OBJ_OFS_DELTA) {
 367                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 368                         unsigned pos = sizeof(dheader) - 1;
 369                         dheader[pos] = ofs & 127;
 370                         while (ofs >>= 7)
 371                                 dheader[--pos] = 128 | (--ofs & 127);
 372                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 373                                 unuse_pack(&w_curs);
 374                                 return 0;
 375                         }
 376                         sha1write(f, header, hdrlen);
 377                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 378                         hdrlen += sizeof(dheader) - pos;
 379                         reused_delta++;
 380                 } else if (type == OBJ_REF_DELTA) {
 381                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 382                                 unuse_pack(&w_curs);
 383                                 return 0;
 384                         }
 385                         sha1write(f, header, hdrlen);
 386                         sha1write(f, entry->delta->idx.sha1, 20);
 387                         hdrlen += 20;
 388                         reused_delta++;
 389                 } else {
 390                         if (limit && hdrlen + datalen + 20 >= limit) {
 391                                 unuse_pack(&w_curs);
 392                                 return 0;
 393                         }
 394                         sha1write(f, header, hdrlen);
 395                 }
 396                 copy_pack_data(f, p, &w_curs, offset, datalen);
 397                 unuse_pack(&w_curs);
 398                 reused++;
 399         }
 400         if (usable_delta)
 401                 written_delta++;
 402         written++;
 403         if (!pack_to_stdout)
 404                 entry->idx.crc32 = crc32_end(f);
 405         return hdrlen + datalen;
 406 }
 407
 408 static int write_one(struct sha1file *f,
 409                                struct object_entry *e,
 410                                off_t *offset)
 411 {
 412         unsigned long size;
 413
 414         /* offset is non zero if object is written already. */
 415         if (e->idx.offset || e->preferred_base)
 416                 return -1;
 417
 418         /* if we are deltified, write out base object first. */
 419         if (e->delta && !write_one(f, e->delta, offset))
 420                 return 0;
 421
 422         e->idx.offset = *offset;
 423         size = write_object(f, e, *offset);
 424         if (!size) {
 425                 e->idx.offset = 0;
 426                 return 0;
 427         }
 428         written_list[nr_written++] = &e->idx;
 429
 430         /* make sure off_t is sufficiently large not to wrap */
 431         if (signed_add_overflows(*offset, size))
 432                 die("pack too large for current definition of off_t");
 433         *offset += size;
 434         return 1;
 435 }
 436
 437 static void write_pack_file(void)
 438 {
 439         uint32_t i = 0, j;
 440         struct sha1file *f;
 441         off_t offset;
 442         struct pack_header hdr;
 443         uint32_t nr_remaining = nr_result;
 444         time_t last_mtime = 0;
 445
 446         if (progress > pack_to_stdout)
 447                 progress_state = start_progress("Writing objects", nr_result);
 448         written_list = xmalloc(nr_objects * sizeof(*written_list));
 449
 450         do {
 451                 unsigned char sha1[20];
 452                 char *pack_tmp_name = NULL;
 453
 454                 if (pack_to_stdout) {
 455                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 456                 } else {
 457                         char tmpname[PATH_MAX];
 458                         int fd;
 459                         fd = odb_mkstemp(tmpname, sizeof(tmpname),
 460                                          "pack/tmp_pack_XXXXXX");
 461                         pack_tmp_name = xstrdup(tmpname);
 462                         f = sha1fd(fd, pack_tmp_name);
 463                 }
 464
 465                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
 466                 hdr.hdr_version = htonl(PACK_VERSION);
 467                 hdr.hdr_entries = htonl(nr_remaining);
 468                 sha1write(f, &hdr, sizeof(hdr));
 469                 offset = sizeof(hdr);
 470                 nr_written = 0;
 471                 for (; i < nr_objects; i++) {
 472                         if (!write_one(f, objects + i, &offset))
 473                                 break;
 474                         display_progress(progress_state, written);
 475                 }
 476
 477                 /*
 478                  * Did we write the wrong # entries in the header?
 479                  * If so, rewrite it like in fast-import
 480                  */
 481                 if (pack_to_stdout) {
 482                         sha1close(f, sha1, CSUM_CLOSE);
 483                 } else if (nr_written == nr_remaining) {
 484                         sha1close(f, sha1, CSUM_FSYNC);
 485                 } else {
 486                         int fd = sha1close(f, sha1, 0);
 487                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
 488                                                  nr_written, sha1, offset);
 489                         close(fd);
 490                 }
 491
 492                 if (!pack_to_stdout) {
 493                         struct stat st;
 494                         const char *idx_tmp_name;
 495                         char tmpname[PATH_MAX];
 496
 497                         idx_tmp_name = write_idx_file(NULL, written_list, nr_written,
 498                                                       &pack_idx_opts, sha1);
 499
 500                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 501                                  base_name, sha1_to_hex(sha1));
 502                         free_pack_by_name(tmpname);
 503                         if (adjust_shared_perm(pack_tmp_name))
 504                                 die_errno("unable to make temporary pack file readable");
 505                         if (rename(pack_tmp_name, tmpname))
 506                                 die_errno("unable to rename temporary pack file");
 507
 508                         /*
 509                          * Packs are runtime accessed in their mtime
 510                          * order since newer packs are more likely to contain
 511                          * younger objects.  So if we are creating multiple
 512                          * packs then we should modify the mtime of later ones
 513                          * to preserve this property.
 514                          */
 515                         if (stat(tmpname, &st) < 0) {
 516                                 warning("failed to stat %s: %s",
 517                                         tmpname, strerror(errno));
 518                         } else if (!last_mtime) {
 519                                 last_mtime = st.st_mtime;
 520                         } else {
 521                                 struct utimbuf utb;
 522                                 utb.actime = st.st_atime;
 523                                 utb.modtime = --last_mtime;
 524                                 if (utime(tmpname, &utb) < 0)
 525                                         warning("failed utime() on %s: %s",
 526                                                 tmpname, strerror(errno));
 527                         }
 528
 529                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 530                                  base_name, sha1_to_hex(sha1));
 531                         if (adjust_shared_perm(idx_tmp_name))
 532                                 die_errno("unable to make temporary index file readable");
 533                         if (rename(idx_tmp_name, tmpname))
 534                                 die_errno("unable to rename temporary index file");
 535
 536                         free((void *) idx_tmp_name);
 537                         free(pack_tmp_name);
 538                         puts(sha1_to_hex(sha1));
 539                 }
 540
 541                 /* mark written objects as written to previous pack */
 542                 for (j = 0; j < nr_written; j++) {
 543                         written_list[j]->offset = (off_t)-1;
 544                 }
 545                 nr_remaining -= nr_written;
 546         } while (nr_remaining && i < nr_objects);
 547
 548         free(written_list);
 549         stop_progress(&progress_state);
 550         if (written != nr_result)
 551                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
 552                         written, nr_result);
 553 }
 554
 555 static int locate_object_entry_hash(const unsigned char *sha1)
 556 {
 557         int i;
 558         unsigned int ui;
 559         memcpy(&ui, sha1, sizeof(unsigned int));
 560         i = ui % object_ix_hashsz;
 561         while (0 < object_ix[i]) {
 562                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 563                         return i;
 564                 if (++i == object_ix_hashsz)
 565                         i = 0;
 566         }
 567         return -1 - i;
 568 }
 569
 570 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 571 {
 572         int i;
 573
 574         if (!object_ix_hashsz)
 575                 return NULL;
 576
 577         i = locate_object_entry_hash(sha1);
 578         if (0 <= i)
 579                 return &objects[object_ix[i]-1];
 580         return NULL;
 581 }
 582
 583 static void rehash_objects(void)
 584 {
 585         uint32_t i;
 586         struct object_entry *oe;
 587
 588         object_ix_hashsz = nr_objects * 3;
 589         if (object_ix_hashsz < 1024)
 590                 object_ix_hashsz = 1024;
 591         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 592         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 593         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 594                 int ix = locate_object_entry_hash(oe->idx.sha1);
 595                 if (0 <= ix)
 596                         continue;
 597                 ix = -1 - ix;
 598                 object_ix[ix] = i + 1;
 599         }
 600 }
 601
 602 static unsigned name_hash(const char *name)
 603 {
 604         unsigned c, hash = 0;
 605
 606         if (!name)
 607                 return 0;
 608
 609         /*
 610          * This effectively just creates a sortable number from the
 611          * last sixteen non-whitespace characters. Last characters
 612          * count "most", so things that end in ".c" sort together.
 613          */
 614         while ((c = *name++) != 0) {
 615                 if (isspace(c))
 616                         continue;
 617                 hash = (hash >> 2) + (c << 24);
 618         }
 619         return hash;
 620 }
 621
 622 static void setup_delta_attr_check(struct git_attr_check *check)
 623 {
 624         static struct git_attr *attr_delta;
 625
 626         if (!attr_delta)
 627                 attr_delta = git_attr("delta");
 628
 629         check[0].attr = attr_delta;
 630 }
 631
 632 static int no_try_delta(const char *path)
 633 {
 634         struct git_attr_check check[1];
 635
 636         setup_delta_attr_check(check);
 637         if (git_checkattr(path, ARRAY_SIZE(check), check))
 638                 return 0;
 639         if (ATTR_FALSE(check->value))
 640                 return 1;
 641         return 0;
 642 }
 643
 644 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 645                             const char *name, int exclude)
 646 {
 647         struct object_entry *entry;
 648         struct packed_git *p, *found_pack = NULL;
 649         off_t found_offset = 0;
 650         int ix;
 651         unsigned hash = name_hash(name);
 652
 653         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 654         if (ix >= 0) {
 655                 if (exclude) {
 656                         entry = objects + object_ix[ix] - 1;
 657                         if (!entry->preferred_base)
 658                                 nr_result--;
 659                         entry->preferred_base = 1;
 660                 }
 661                 return 0;
 662         }
 663
 664         if (!exclude && local && has_loose_object_nonlocal(sha1))
 665                 return 0;
 666
 667         for (p = packed_git; p; p = p->next) {
 668                 off_t offset = find_pack_entry_one(sha1, p);
 669                 if (offset) {
 670                         if (!found_pack) {
 671                                 found_offset = offset;
 672                                 found_pack = p;
 673                         }
 674                         if (exclude)
 675                                 break;
 676                         if (incremental)
 677                                 return 0;
 678                         if (local && !p->pack_local)
 679                                 return 0;
 680                         if (ignore_packed_keep && p->pack_local && p->pack_keep)
 681                                 return 0;
 682                 }
 683         }
 684
 685         if (nr_objects >= nr_alloc) {
 686                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 687                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 688         }
 689
 690         entry = objects + nr_objects++;
 691         memset(entry, 0, sizeof(*entry));
 692         hashcpy(entry->idx.sha1, sha1);
 693         entry->hash = hash;
 694         if (type)
 695                 entry->type = type;
 696         if (exclude)
 697                 entry->preferred_base = 1;
 698         else
 699                 nr_result++;
 700         if (found_pack) {
 701                 entry->in_pack = found_pack;
 702                 entry->in_pack_offset = found_offset;
 703         }
 704
 705         if (object_ix_hashsz * 3 <= nr_objects * 4)
 706                 rehash_objects();
 707         else
 708                 object_ix[-1 - ix] = nr_objects;
 709
 710         display_progress(progress_state, nr_objects);
 711
 712         if (name && no_try_delta(name))
 713                 entry->no_try_delta = 1;
 714
 715         return 1;
 716 }
 717
 718 struct pbase_tree_cache {
 719         unsigned char sha1[20];
 720         int ref;
 721         int temporary;
 722         void *tree_data;
 723         unsigned long tree_size;
 724 };
 725
 726 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 727 static int pbase_tree_cache_ix(const unsigned char *sha1)
 728 {
 729         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 730 }
 731 static int pbase_tree_cache_ix_incr(int ix)
 732 {
 733         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 734 }
 735
 736 static struct pbase_tree {
 737         struct pbase_tree *next;
 738         /* This is a phony "cache" entry; we are not
 739          * going to evict it nor find it through _get()
 740          * mechanism -- this is for the toplevel node that
 741          * would almost always change with any commit.
 742          */
 743         struct pbase_tree_cache pcache;
 744 } *pbase_tree;
 745
 746 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 747 {
 748         struct pbase_tree_cache *ent, *nent;
 749         void *data;
 750         unsigned long size;
 751         enum object_type type;
 752         int neigh;
 753         int my_ix = pbase_tree_cache_ix(sha1);
 754         int available_ix = -1;
 755
 756         /* pbase-tree-cache acts as a limited hashtable.
 757          * your object will be found at your index or within a few
 758          * slots after that slot if it is cached.
 759          */
 760         for (neigh = 0; neigh < 8; neigh++) {
 761                 ent = pbase_tree_cache[my_ix];
 762                 if (ent && !hashcmp(ent->sha1, sha1)) {
 763                         ent->ref++;
 764                         return ent;
 765                 }
 766                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 767                          ((0 <= available_ix) &&
 768                           (!ent && pbase_tree_cache[available_ix])))
 769                         available_ix = my_ix;
 770                 if (!ent)
 771                         break;
 772                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 773         }
 774
 775         /* Did not find one.  Either we got a bogus request or
 776          * we need to read and perhaps cache.
 777          */
 778         data = read_sha1_file(sha1, &type, &size);
 779         if (!data)
 780                 return NULL;
 781         if (type != OBJ_TREE) {
 782                 free(data);
 783                 return NULL;
 784         }
 785
 786         /* We need to either cache or return a throwaway copy */
 787
 788         if (available_ix < 0)
 789                 ent = NULL;
 790         else {
 791                 ent = pbase_tree_cache[available_ix];
 792                 my_ix = available_ix;
 793         }
 794
 795         if (!ent) {
 796                 nent = xmalloc(sizeof(*nent));
 797                 nent->temporary = (available_ix < 0);
 798         }
 799         else {
 800                 /* evict and reuse */
 801                 free(ent->tree_data);
 802                 nent = ent;
 803         }
 804         hashcpy(nent->sha1, sha1);
 805         nent->tree_data = data;
 806         nent->tree_size = size;
 807         nent->ref = 1;
 808         if (!nent->temporary)
 809                 pbase_tree_cache[my_ix] = nent;
 810         return nent;
 811 }
 812
 813 static void pbase_tree_put(struct pbase_tree_cache *cache)
 814 {
 815         if (!cache->temporary) {
 816                 cache->ref--;
 817                 return;
 818         }
 819         free(cache->tree_data);
 820         free(cache);
 821 }
 822
 823 static int name_cmp_len(const char *name)
 824 {
 825         int i;
 826         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 827                 ;
 828         return i;
 829 }
 830
 831 static void add_pbase_object(struct tree_desc *tree,
 832                              const char *name,
 833                              int cmplen,
 834                              const char *fullname)
 835 {
 836         struct name_entry entry;
 837         int cmp;
 838
 839         while (tree_entry(tree,&entry)) {
 840                 if (S_ISGITLINK(entry.mode))
 841                         continue;
 842                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 843                       memcmp(name, entry.path, cmplen);
 844                 if (cmp > 0)
 845                         continue;
 846                 if (cmp < 0)
 847                         return;
 848                 if (name[cmplen] != '/') {
 849                         add_object_entry(entry.sha1,
 850                                          object_type(entry.mode),
 851                                          fullname, 1);
 852                         return;
 853                 }
 854                 if (S_ISDIR(entry.mode)) {
 855                         struct tree_desc sub;
 856                         struct pbase_tree_cache *tree;
 857                         const char *down = name+cmplen+1;
 858                         int downlen = name_cmp_len(down);
 859
 860                         tree = pbase_tree_get(entry.sha1);
 861                         if (!tree)
 862                                 return;
 863                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 864
 865                         add_pbase_object(&sub, down, downlen, fullname);
 866                         pbase_tree_put(tree);
 867                 }
 868         }
 869 }
 870
 871 static unsigned *done_pbase_paths;
 872 static int done_pbase_paths_num;
 873 static int done_pbase_paths_alloc;
 874 static int done_pbase_path_pos(unsigned hash)
 875 {
 876         int lo = 0;
 877         int hi = done_pbase_paths_num;
 878         while (lo < hi) {
 879                 int mi = (hi + lo) / 2;
 880                 if (done_pbase_paths[mi] == hash)
 881                         return mi;
 882                 if (done_pbase_paths[mi] < hash)
 883                         hi = mi;
 884                 else
 885                         lo = mi + 1;
 886         }
 887         return -lo-1;
 888 }
 889
 890 static int check_pbase_path(unsigned hash)
 891 {
 892         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 893         if (0 <= pos)
 894                 return 1;
 895         pos = -pos - 1;
 896         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 897                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 898                 done_pbase_paths = xrealloc(done_pbase_paths,
 899                                             done_pbase_paths_alloc *
 900                                             sizeof(unsigned));
 901         }
 902         done_pbase_paths_num++;
 903         if (pos < done_pbase_paths_num)
 904                 memmove(done_pbase_paths + pos + 1,
 905                         done_pbase_paths + pos,
 906                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 907         done_pbase_paths[pos] = hash;
 908         return 0;
 909 }
 910
 911 static void add_preferred_base_object(const char *name)
 912 {
 913         struct pbase_tree *it;
 914         int cmplen;
 915         unsigned hash = name_hash(name);
 916
 917         if (!num_preferred_base || check_pbase_path(hash))
 918                 return;
 919
 920         cmplen = name_cmp_len(name);
 921         for (it = pbase_tree; it; it = it->next) {
 922                 if (cmplen == 0) {
 923                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 924                 }
 925                 else {
 926                         struct tree_desc tree;
 927                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 928                         add_pbase_object(&tree, name, cmplen, name);
 929                 }
 930         }
 931 }
 932
 933 static void add_preferred_base(unsigned char *sha1)
 934 {
 935         struct pbase_tree *it;
 936         void *data;
 937         unsigned long size;
 938         unsigned char tree_sha1[20];
 939
 940         if (window <= num_preferred_base++)
 941                 return;
 942
 943         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 944         if (!data)
 945                 return;
 946
 947         for (it = pbase_tree; it; it = it->next) {
 948                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 949                         free(data);
 950                         return;
 951                 }
 952         }
 953
 954         it = xcalloc(1, sizeof(*it));
 955         it->next = pbase_tree;
 956         pbase_tree = it;
 957
 958         hashcpy(it->pcache.sha1, tree_sha1);
 959         it->pcache.tree_data = data;
 960         it->pcache.tree_size = size;
 961 }
 962
 963 static void cleanup_preferred_base(void)
 964 {
 965         struct pbase_tree *it;
 966         unsigned i;
 967
 968         it = pbase_tree;
 969         pbase_tree = NULL;
 970         while (it) {
 971                 struct pbase_tree *this = it;
 972                 it = this->next;
 973                 free(this->pcache.tree_data);
 974                 free(this);
 975         }
 976
 977         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
 978                 if (!pbase_tree_cache[i])
 979                         continue;
 980                 free(pbase_tree_cache[i]->tree_data);
 981                 free(pbase_tree_cache[i]);
 982                 pbase_tree_cache[i] = NULL;
 983         }
 984
 985         free(done_pbase_paths);
 986         done_pbase_paths = NULL;
 987         done_pbase_paths_num = done_pbase_paths_alloc = 0;
 988 }
 989
 990 static void check_object(struct object_entry *entry)
 991 {
 992         if (entry->in_pack) {
 993                 struct packed_git *p = entry->in_pack;
 994                 struct pack_window *w_curs = NULL;
 995                 const unsigned char *base_ref = NULL;
 996                 struct object_entry *base_entry;
 997                 unsigned long used, used_0;
 998                 unsigned int avail;
 999                 off_t ofs;
1000                 unsigned char *buf, c;
1001
1002                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1003
1004                 /*
1005                  * We want in_pack_type even if we do not reuse delta
1006                  * since non-delta representations could still be reused.
1007                  */
1008                 used = unpack_object_header_buffer(buf, avail,
1009                                                    &entry->in_pack_type,
1010                                                    &entry->size);
1011                 if (used == 0)
1012                         goto give_up;
1013
1014                 /*
1015                  * Determine if this is a delta and if so whether we can
1016                  * reuse it or not.  Otherwise let's find out as cheaply as
1017                  * possible what the actual type and size for this object is.
1018                  */
1019                 switch (entry->in_pack_type) {
1020                 default:
1021                         /* Not a delta hence we've already got all we need. */
1022                         entry->type = entry->in_pack_type;
1023                         entry->in_pack_header_size = used;
1024                         if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1025                                 goto give_up;
1026                         unuse_pack(&w_curs);
1027                         return;
1028                 case OBJ_REF_DELTA:
1029                         if (reuse_delta && !entry->preferred_base)
1030                                 base_ref = use_pack(p, &w_curs,
1031                                                 entry->in_pack_offset + used, NULL);
1032                         entry->in_pack_header_size = used + 20;
1033                         break;
1034                 case OBJ_OFS_DELTA:
1035                         buf = use_pack(p, &w_curs,
1036                                        entry->in_pack_offset + used, NULL);
1037                         used_0 = 0;
1038                         c = buf[used_0++];
1039                         ofs = c & 127;
1040                         while (c & 128) {
1041                                 ofs += 1;
1042                                 if (!ofs || MSB(ofs, 7)) {
1043                                         error("delta base offset overflow in pack for %s",
1044                                               sha1_to_hex(entry->idx.sha1));
1045                                         goto give_up;
1046                                 }
1047                                 c = buf[used_0++];
1048                                 ofs = (ofs << 7) + (c & 127);
1049                         }
1050                         ofs = entry->in_pack_offset - ofs;
1051                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1052                                 error("delta base offset out of bound for %s",
1053                                       sha1_to_hex(entry->idx.sha1));
1054                                 goto give_up;
1055                         }
1056                         if (reuse_delta && !entry->preferred_base) {
1057                                 struct revindex_entry *revidx;
1058                                 revidx = find_pack_revindex(p, ofs);
1059                                 if (!revidx)
1060                                         goto give_up;
1061                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1062                         }
1063                         entry->in_pack_header_size = used + used_0;
1064                         break;
1065                 }
1066
1067                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1068                         /*
1069                          * If base_ref was set above that means we wish to
1070                          * reuse delta data, and we even found that base
1071                          * in the list of objects we want to pack. Goodie!
1072                          *
1073                          * Depth value does not matter - find_deltas() will
1074                          * never consider reused delta as the base object to
1075                          * deltify other objects against, in order to avoid
1076                          * circular deltas.
1077                          */
1078                         entry->type = entry->in_pack_type;
1079                         entry->delta = base_entry;
1080                         entry->delta_size = entry->size;
1081                         entry->delta_sibling = base_entry->delta_child;
1082                         base_entry->delta_child = entry;
1083                         unuse_pack(&w_curs);
1084                         return;
1085                 }
1086
1087                 if (entry->type) {
1088                         /*
1089                          * This must be a delta and we already know what the
1090                          * final object type is.  Let's extract the actual
1091                          * object size from the delta header.
1092                          */
1093                         entry->size = get_size_from_delta(p, &w_curs,
1094                                         entry->in_pack_offset + entry->in_pack_header_size);
1095                         if (entry->size == 0)
1096                                 goto give_up;
1097                         unuse_pack(&w_curs);
1098                         return;
1099                 }
1100
1101                 /*
1102                  * No choice but to fall back to the recursive delta walk
1103                  * with sha1_object_info() to find about the object type
1104                  * at this point...
1105                  */
1106                 give_up:
1107                 unuse_pack(&w_curs);
1108         }
1109
1110         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1111         /*
1112          * The error condition is checked in prepare_pack().  This is
1113          * to permit a missing preferred base object to be ignored
1114          * as a preferred base.  Doing so can result in a larger
1115          * pack file, but the transfer will still take place.
1116          */
1117 }
1118
1119 static int pack_offset_sort(const void *_a, const void *_b)
1120 {
1121         const struct object_entry *a = *(struct object_entry **)_a;
1122         const struct object_entry *b = *(struct object_entry **)_b;
1123
1124         /* avoid filesystem trashing with loose objects */
1125         if (!a->in_pack && !b->in_pack)
1126                 return hashcmp(a->idx.sha1, b->idx.sha1);
1127
1128         if (a->in_pack < b->in_pack)
1129                 return -1;
1130         if (a->in_pack > b->in_pack)
1131                 return 1;
1132         return a->in_pack_offset < b->in_pack_offset ? -1 :
1133                         (a->in_pack_offset > b->in_pack_offset);
1134 }
1135
1136 static void get_object_details(void)
1137 {
1138         uint32_t i;
1139         struct object_entry **sorted_by_offset;
1140
1141         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1142         for (i = 0; i < nr_objects; i++)
1143                 sorted_by_offset[i] = objects + i;
1144         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1145
1146         for (i = 0; i < nr_objects; i++)
1147                 check_object(sorted_by_offset[i]);
1148
1149         free(sorted_by_offset);
1150 }
1151
1152 /*
1153  * We search for deltas in a list sorted by type, by filename hash, and then
1154  * by size, so that we see progressively smaller and smaller files.
1155  * That's because we prefer deltas to be from the bigger file
1156  * to the smaller -- deletes are potentially cheaper, but perhaps
1157  * more importantly, the bigger file is likely the more recent
1158  * one.  The deepest deltas are therefore the oldest objects which are
1159  * less susceptible to be accessed often.
1160  */
1161 static int type_size_sort(const void *_a, const void *_b)
1162 {
1163         const struct object_entry *a = *(struct object_entry **)_a;
1164         const struct object_entry *b = *(struct object_entry **)_b;
1165
1166         if (a->type > b->type)
1167                 return -1;
1168         if (a->type < b->type)
1169                 return 1;
1170         if (a->hash > b->hash)
1171                 return -1;
1172         if (a->hash < b->hash)
1173                 return 1;
1174         if (a->preferred_base > b->preferred_base)
1175                 return -1;
1176         if (a->preferred_base < b->preferred_base)
1177                 return 1;
1178         if (a->size > b->size)
1179                 return -1;
1180         if (a->size < b->size)
1181                 return 1;
1182         return a < b ? -1 : (a > b);  /* newest first */
1183 }
1184
1185 struct unpacked {
1186         struct object_entry *entry;
1187         void *data;
1188         struct delta_index *index;
1189         unsigned depth;
1190 };
1191
1192 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1193                            unsigned long delta_size)
1194 {
1195         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1196                 return 0;
1197
1198         if (delta_size < cache_max_small_delta_size)
1199                 return 1;
1200
1201         /* cache delta, if objects are large enough compared to delta size */
1202         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1203                 return 1;
1204
1205         return 0;
1206 }
1207
1208 #ifndef NO_PTHREADS
1209
1210 static pthread_mutex_t read_mutex;
1211 #define read_lock()             pthread_mutex_lock(&read_mutex)
1212 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1213
1214 static pthread_mutex_t cache_mutex;
1215 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1216 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1217
1218 static pthread_mutex_t progress_mutex;
1219 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1220 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1221
1222 #else
1223
1224 #define read_lock()             (void)0
1225 #define read_unlock()           (void)0
1226 #define cache_lock()            (void)0
1227 #define cache_unlock()          (void)0
1228 #define progress_lock()         (void)0
1229 #define progress_unlock()       (void)0
1230
1231 #endif
1232
1233 static int try_delta(struct unpacked *trg, struct unpacked *src,
1234                      unsigned max_depth, unsigned long *mem_usage)
1235 {
1236         struct object_entry *trg_entry = trg->entry;
1237         struct object_entry *src_entry = src->entry;
1238         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1239         unsigned ref_depth;
1240         enum object_type type;
1241         void *delta_buf;
1242
1243         /* Don't bother doing diffs between different types */
1244         if (trg_entry->type != src_entry->type)
1245                 return -1;
1246
1247         /*
1248          * We do not bother to try a delta that we discarded
1249          * on an earlier try, but only when reusing delta data.
1250          */
1251         if (reuse_delta && trg_entry->in_pack &&
1252             trg_entry->in_pack == src_entry->in_pack &&
1253             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1254             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1255                 return 0;
1256
1257         /* Let's not bust the allowed depth. */
1258         if (src->depth >= max_depth)
1259                 return 0;
1260
1261         /* Now some size filtering heuristics. */
1262         trg_size = trg_entry->size;
1263         if (!trg_entry->delta) {
1264                 max_size = trg_size/2 - 20;
1265                 ref_depth = 1;
1266         } else {
1267                 max_size = trg_entry->delta_size;
1268                 ref_depth = trg->depth;
1269         }
1270         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1271                                                 (max_depth - ref_depth + 1);
1272         if (max_size == 0)
1273                 return 0;
1274         src_size = src_entry->size;
1275         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1276         if (sizediff >= max_size)
1277                 return 0;
1278         if (trg_size < src_size / 32)
1279                 return 0;
1280
1281         /* Load data if not already done */
1282         if (!trg->data) {
1283                 read_lock();
1284                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1285                 read_unlock();
1286                 if (!trg->data)
1287                         die("object %s cannot be read",
1288                             sha1_to_hex(trg_entry->idx.sha1));
1289                 if (sz != trg_size)
1290                         die("object %s inconsistent object length (%lu vs %lu)",
1291                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1292                 *mem_usage += sz;
1293         }
1294         if (!src->data) {
1295                 read_lock();
1296                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1297                 read_unlock();
1298                 if (!src->data) {
1299                         if (src_entry->preferred_base) {
1300                                 static int warned = 0;
1301                                 if (!warned++)
1302                                         warning("object %s cannot be read",
1303                                                 sha1_to_hex(src_entry->idx.sha1));
1304                                 /*
1305                                  * Those objects are not included in the
1306                                  * resulting pack.  Be resilient and ignore
1307                                  * them if they can't be read, in case the
1308                                  * pack could be created nevertheless.
1309                                  */
1310                                 return 0;
1311                         }
1312                         die("object %s cannot be read",
1313                             sha1_to_hex(src_entry->idx.sha1));
1314                 }
1315                 if (sz != src_size)
1316                         die("object %s inconsistent object length (%lu vs %lu)",
1317                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1318                 *mem_usage += sz;
1319         }
1320         if (!src->index) {
1321                 src->index = create_delta_index(src->data, src_size);
1322                 if (!src->index) {
1323                         static int warned = 0;
1324                         if (!warned++)
1325                                 warning("suboptimal pack - out of memory");
1326                         return 0;
1327                 }
1328                 *mem_usage += sizeof_delta_index(src->index);
1329         }
1330
1331         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1332         if (!delta_buf)
1333                 return 0;
1334
1335         if (trg_entry->delta) {
1336                 /* Prefer only shallower same-sized deltas. */
1337                 if (delta_size == trg_entry->delta_size &&
1338                     src->depth + 1 >= trg->depth) {
1339                         free(delta_buf);
1340                         return 0;
1341                 }
1342         }
1343
1344         /*
1345          * Handle memory allocation outside of the cache
1346          * accounting lock.  Compiler will optimize the strangeness
1347          * away when NO_PTHREADS is defined.
1348          */
1349         free(trg_entry->delta_data);
1350         cache_lock();
1351         if (trg_entry->delta_data) {
1352                 delta_cache_size -= trg_entry->delta_size;
1353                 trg_entry->delta_data = NULL;
1354         }
1355         if (delta_cacheable(src_size, trg_size, delta_size)) {
1356                 delta_cache_size += delta_size;
1357                 cache_unlock();
1358                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1359         } else {
1360                 cache_unlock();
1361                 free(delta_buf);
1362         }
1363
1364         trg_entry->delta = src_entry;
1365         trg_entry->delta_size = delta_size;
1366         trg->depth = src->depth + 1;
1367
1368         return 1;
1369 }
1370
1371 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1372 {
1373         struct object_entry *child = me->delta_child;
1374         unsigned int m = n;
1375         while (child) {
1376                 unsigned int c = check_delta_limit(child, n + 1);
1377                 if (m < c)
1378                         m = c;
1379                 child = child->delta_sibling;
1380         }
1381         return m;
1382 }
1383
1384 static unsigned long free_unpacked(struct unpacked *n)
1385 {
1386         unsigned long freed_mem = sizeof_delta_index(n->index);
1387         free_delta_index(n->index);
1388         n->index = NULL;
1389         if (n->data) {
1390                 freed_mem += n->entry->size;
1391                 free(n->data);
1392                 n->data = NULL;
1393         }
1394         n->entry = NULL;
1395         n->depth = 0;
1396         return freed_mem;
1397 }
1398
1399 static void find_deltas(struct object_entry **list, unsigned *list_size,
1400                         int window, int depth, unsigned *processed)
1401 {
1402         uint32_t i, idx = 0, count = 0;
1403         struct unpacked *array;
1404         unsigned long mem_usage = 0;
1405
1406         array = xcalloc(window, sizeof(struct unpacked));
1407
1408         for (;;) {
1409                 struct object_entry *entry;
1410                 struct unpacked *n = array + idx;
1411                 int j, max_depth, best_base = -1;
1412
1413                 progress_lock();
1414                 if (!*list_size) {
1415                         progress_unlock();
1416                         break;
1417                 }
1418                 entry = *list++;
1419                 (*list_size)--;
1420                 if (!entry->preferred_base) {
1421                         (*processed)++;
1422                         display_progress(progress_state, *processed);
1423                 }
1424                 progress_unlock();
1425
1426                 mem_usage -= free_unpacked(n);
1427                 n->entry = entry;
1428
1429                 while (window_memory_limit &&
1430                        mem_usage > window_memory_limit &&
1431                        count > 1) {
1432                         uint32_t tail = (idx + window - count) % window;
1433                         mem_usage -= free_unpacked(array + tail);
1434                         count--;
1435                 }
1436
1437                 /* We do not compute delta to *create* objects we are not
1438                  * going to pack.
1439                  */
1440                 if (entry->preferred_base)
1441                         goto next;
1442
1443                 /*
1444                  * If the current object is at pack edge, take the depth the
1445                  * objects that depend on the current object into account
1446                  * otherwise they would become too deep.
1447                  */
1448                 max_depth = depth;
1449                 if (entry->delta_child) {
1450                         max_depth -= check_delta_limit(entry, 0);
1451                         if (max_depth <= 0)
1452                                 goto next;
1453                 }
1454
1455                 j = window;
1456                 while (--j > 0) {
1457                         int ret;
1458                         uint32_t other_idx = idx + j;
1459                         struct unpacked *m;
1460                         if (other_idx >= window)
1461                                 other_idx -= window;
1462                         m = array + other_idx;
1463                         if (!m->entry)
1464                                 break;
1465                         ret = try_delta(n, m, max_depth, &mem_usage);
1466                         if (ret < 0)
1467                                 break;
1468                         else if (ret > 0)
1469                                 best_base = other_idx;
1470                 }
1471
1472                 /*
1473                  * If we decided to cache the delta data, then it is best
1474                  * to compress it right away.  First because we have to do
1475                  * it anyway, and doing it here while we're threaded will
1476                  * save a lot of time in the non threaded write phase,
1477                  * as well as allow for caching more deltas within
1478                  * the same cache size limit.
1479                  * ...
1480                  * But only if not writing to stdout, since in that case
1481                  * the network is most likely throttling writes anyway,
1482                  * and therefore it is best to go to the write phase ASAP
1483                  * instead, as we can afford spending more time compressing
1484                  * between writes at that moment.
1485                  */
1486                 if (entry->delta_data && !pack_to_stdout) {
1487                         entry->z_delta_size = do_compress(&entry->delta_data,
1488                                                           entry->delta_size);
1489                         cache_lock();
1490                         delta_cache_size -= entry->delta_size;
1491                         delta_cache_size += entry->z_delta_size;
1492                         cache_unlock();
1493                 }
1494
1495                 /* if we made n a delta, and if n is already at max
1496                  * depth, leaving it in the window is pointless.  we
1497                  * should evict it first.
1498                  */
1499                 if (entry->delta && max_depth <= n->depth)
1500                         continue;
1501
1502                 /*
1503                  * Move the best delta base up in the window, after the
1504                  * currently deltified object, to keep it longer.  It will
1505                  * be the first base object to be attempted next.
1506                  */
1507                 if (entry->delta) {
1508                         struct unpacked swap = array[best_base];
1509                         int dist = (window + idx - best_base) % window;
1510                         int dst = best_base;
1511                         while (dist--) {
1512                                 int src = (dst + 1) % window;
1513                                 array[dst] = array[src];
1514                                 dst = src;
1515                         }
1516                         array[dst] = swap;
1517                 }
1518
1519                 next:
1520                 idx++;
1521                 if (count + 1 < window)
1522                         count++;
1523                 if (idx >= window)
1524                         idx = 0;
1525         }
1526
1527         for (i = 0; i < window; ++i) {
1528                 free_delta_index(array[i].index);
1529                 free(array[i].data);
1530         }
1531         free(array);
1532 }
1533
1534 #ifndef NO_PTHREADS
1535
1536 static void try_to_free_from_threads(size_t size)
1537 {
1538         read_lock();
1539         release_pack_memory(size, -1);
1540         read_unlock();
1541 }
1542
1543 static try_to_free_t old_try_to_free_routine;
1544
1545 /*
1546  * The main thread waits on the condition that (at least) one of the workers
1547  * has stopped working (which is indicated in the .working member of
1548  * struct thread_params).
1549  * When a work thread has completed its work, it sets .working to 0 and
1550  * signals the main thread and waits on the condition that .data_ready
1551  * becomes 1.
1552  */
1553
1554 struct thread_params {
1555         pthread_t thread;
1556         struct object_entry **list;
1557         unsigned list_size;
1558         unsigned remaining;
1559         int window;
1560         int depth;
1561         int working;
1562         int data_ready;
1563         pthread_mutex_t mutex;
1564         pthread_cond_t cond;
1565         unsigned *processed;
1566 };
1567
1568 static pthread_cond_t progress_cond;
1569
1570 /*
1571  * Mutex and conditional variable can't be statically-initialized on Windows.
1572  */
1573 static void init_threaded_search(void)
1574 {
1575         init_recursive_mutex(&read_mutex);
1576         pthread_mutex_init(&cache_mutex, NULL);
1577         pthread_mutex_init(&progress_mutex, NULL);
1578         pthread_cond_init(&progress_cond, NULL);
1579         old_try_to_free_routine = set_try_to_free_routine(try_to_free_from_threads);
1580 }
1581
1582 static void cleanup_threaded_search(void)
1583 {
1584         set_try_to_free_routine(old_try_to_free_routine);
1585         pthread_cond_destroy(&progress_cond);
1586         pthread_mutex_destroy(&read_mutex);
1587         pthread_mutex_destroy(&cache_mutex);
1588         pthread_mutex_destroy(&progress_mutex);
1589 }
1590
1591 static void *threaded_find_deltas(void *arg)
1592 {
1593         struct thread_params *me = arg;
1594
1595         while (me->remaining) {
1596                 find_deltas(me->list, &me->remaining,
1597                             me->window, me->depth, me->processed);
1598
1599                 progress_lock();
1600                 me->working = 0;
1601                 pthread_cond_signal(&progress_cond);
1602                 progress_unlock();
1603
1604                 /*
1605                  * We must not set ->data_ready before we wait on the
1606                  * condition because the main thread may have set it to 1
1607                  * before we get here. In order to be sure that new
1608                  * work is available if we see 1 in ->data_ready, it
1609                  * was initialized to 0 before this thread was spawned
1610                  * and we reset it to 0 right away.
1611                  */
1612                 pthread_mutex_lock(&me->mutex);
1613                 while (!me->data_ready)
1614                         pthread_cond_wait(&me->cond, &me->mutex);
1615                 me->data_ready = 0;
1616                 pthread_mutex_unlock(&me->mutex);
1617         }
1618         /* leave ->working 1 so that this doesn't get more work assigned */
1619         return NULL;
1620 }
1621
1622 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1623                            int window, int depth, unsigned *processed)
1624 {
1625         struct thread_params *p;
1626         int i, ret, active_threads = 0;
1627
1628         init_threaded_search();
1629
1630         if (!delta_search_threads)      /* --threads=0 means autodetect */
1631                 delta_search_threads = online_cpus();
1632         if (delta_search_threads <= 1) {
1633                 find_deltas(list, &list_size, window, depth, processed);
1634                 cleanup_threaded_search();
1635                 return;
1636         }
1637         if (progress > pack_to_stdout)
1638                 fprintf(stderr, "Delta compression using up to %d threads.\n",
1639                                 delta_search_threads);
1640         p = xcalloc(delta_search_threads, sizeof(*p));
1641
1642         /* Partition the work amongst work threads. */
1643         for (i = 0; i < delta_search_threads; i++) {
1644                 unsigned sub_size = list_size / (delta_search_threads - i);
1645
1646                 /* don't use too small segments or no deltas will be found */
1647                 if (sub_size < 2*window && i+1 < delta_search_threads)
1648                         sub_size = 0;
1649
1650                 p[i].window = window;
1651                 p[i].depth = depth;
1652                 p[i].processed = processed;
1653                 p[i].working = 1;
1654                 p[i].data_ready = 0;
1655
1656                 /* try to split chunks on "path" boundaries */
1657                 while (sub_size && sub_size < list_size &&
1658                        list[sub_size]->hash &&
1659                        list[sub_size]->hash == list[sub_size-1]->hash)
1660                         sub_size++;
1661
1662                 p[i].list = list;
1663                 p[i].list_size = sub_size;
1664                 p[i].remaining = sub_size;
1665
1666                 list += sub_size;
1667                 list_size -= sub_size;
1668         }
1669
1670         /* Start work threads. */
1671         for (i = 0; i < delta_search_threads; i++) {
1672                 if (!p[i].list_size)
1673                         continue;
1674                 pthread_mutex_init(&p[i].mutex, NULL);
1675                 pthread_cond_init(&p[i].cond, NULL);
1676                 ret = pthread_create(&p[i].thread, NULL,
1677                                      threaded_find_deltas, &p[i]);
1678                 if (ret)
1679                         die("unable to create thread: %s", strerror(ret));
1680                 active_threads++;
1681         }
1682
1683         /*
1684          * Now let's wait for work completion.  Each time a thread is done
1685          * with its work, we steal half of the remaining work from the
1686          * thread with the largest number of unprocessed objects and give
1687          * it to that newly idle thread.  This ensure good load balancing
1688          * until the remaining object list segments are simply too short
1689          * to be worth splitting anymore.
1690          */
1691         while (active_threads) {
1692                 struct thread_params *target = NULL;
1693                 struct thread_params *victim = NULL;
1694                 unsigned sub_size = 0;
1695
1696                 progress_lock();
1697                 for (;;) {
1698                         for (i = 0; !target && i < delta_search_threads; i++)
1699                                 if (!p[i].working)
1700                                         target = &p[i];
1701                         if (target)
1702                                 break;
1703                         pthread_cond_wait(&progress_cond, &progress_mutex);
1704                 }
1705
1706                 for (i = 0; i < delta_search_threads; i++)
1707                         if (p[i].remaining > 2*window &&
1708                             (!victim || victim->remaining < p[i].remaining))
1709                                 victim = &p[i];
1710                 if (victim) {
1711                         sub_size = victim->remaining / 2;
1712                         list = victim->list + victim->list_size - sub_size;
1713                         while (sub_size && list[0]->hash &&
1714                                list[0]->hash == list[-1]->hash) {
1715                                 list++;
1716                                 sub_size--;
1717                         }
1718                         if (!sub_size) {
1719                                 /*
1720                                  * It is possible for some "paths" to have
1721                                  * so many objects that no hash boundary
1722                                  * might be found.  Let's just steal the
1723                                  * exact half in that case.
1724                                  */
1725                                 sub_size = victim->remaining / 2;
1726                                 list -= sub_size;
1727                         }
1728                         target->list = list;
1729                         victim->list_size -= sub_size;
1730                         victim->remaining -= sub_size;
1731                 }
1732                 target->list_size = sub_size;
1733                 target->remaining = sub_size;
1734                 target->working = 1;
1735                 progress_unlock();
1736
1737                 pthread_mutex_lock(&target->mutex);
1738                 target->data_ready = 1;
1739                 pthread_cond_signal(&target->cond);
1740                 pthread_mutex_unlock(&target->mutex);
1741
1742                 if (!sub_size) {
1743                         pthread_join(target->thread, NULL);
1744                         pthread_cond_destroy(&target->cond);
1745                         pthread_mutex_destroy(&target->mutex);
1746                         active_threads--;
1747                 }
1748         }
1749         cleanup_threaded_search();
1750         free(p);
1751 }
1752
1753 #else
1754 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1755 #endif
1756
1757 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1758 {
1759         unsigned char peeled[20];
1760
1761         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1762             !peel_ref(path, peeled)        && /* peelable? */
1763             !is_null_sha1(peeled)          && /* annotated tag? */
1764             locate_object_entry(peeled))      /* object packed? */
1765                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1766         return 0;
1767 }
1768
1769 static void prepare_pack(int window, int depth)
1770 {
1771         struct object_entry **delta_list;
1772         uint32_t i, nr_deltas;
1773         unsigned n;
1774
1775         get_object_details();
1776
1777         /*
1778          * If we're locally repacking then we need to be doubly careful
1779          * from now on in order to make sure no stealth corruption gets
1780          * propagated to the new pack.  Clients receiving streamed packs
1781          * should validate everything they get anyway so no need to incur
1782          * the additional cost here in that case.
1783          */
1784         if (!pack_to_stdout)
1785                 do_check_packed_object_crc = 1;
1786
1787         if (!nr_objects || !window || !depth)
1788                 return;
1789
1790         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1791         nr_deltas = n = 0;
1792
1793         for (i = 0; i < nr_objects; i++) {
1794                 struct object_entry *entry = objects + i;
1795
1796                 if (entry->delta)
1797                         /* This happens if we decided to reuse existing
1798                          * delta from a pack.  "reuse_delta &&" is implied.
1799                          */
1800                         continue;
1801
1802                 if (entry->size < 50)
1803                         continue;
1804
1805                 if (entry->no_try_delta)
1806                         continue;
1807
1808                 if (!entry->preferred_base) {
1809                         nr_deltas++;
1810                         if (entry->type < 0)
1811                                 die("unable to get type of object %s",
1812                                     sha1_to_hex(entry->idx.sha1));
1813                 } else {
1814                         if (entry->type < 0) {
1815                                 /*
1816                                  * This object is not found, but we
1817                                  * don't have to include it anyway.
1818                                  */
1819                                 continue;
1820                         }
1821                 }
1822
1823                 delta_list[n++] = entry;
1824         }
1825
1826         if (nr_deltas && n > 1) {
1827                 unsigned nr_done = 0;
1828                 if (progress)
1829                         progress_state = start_progress("Compressing objects",
1830                                                         nr_deltas);
1831                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1832                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1833                 stop_progress(&progress_state);
1834                 if (nr_done != nr_deltas)
1835                         die("inconsistency with delta count");
1836         }
1837         free(delta_list);
1838 }
1839
1840 static int git_pack_config(const char *k, const char *v, void *cb)
1841 {
1842         if (!strcmp(k, "pack.window")) {
1843                 window = git_config_int(k, v);
1844                 return 0;
1845         }
1846         if (!strcmp(k, "pack.windowmemory")) {
1847                 window_memory_limit = git_config_ulong(k, v);
1848                 return 0;
1849         }
1850         if (!strcmp(k, "pack.depth")) {
1851                 depth = git_config_int(k, v);
1852                 return 0;
1853         }
1854         if (!strcmp(k, "pack.compression")) {
1855                 int level = git_config_int(k, v);
1856                 if (level == -1)
1857                         level = Z_DEFAULT_COMPRESSION;
1858                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1859                         die("bad pack compression level %d", level);
1860                 pack_compression_level = level;
1861                 pack_compression_seen = 1;
1862                 return 0;
1863         }
1864         if (!strcmp(k, "pack.deltacachesize")) {
1865                 max_delta_cache_size = git_config_int(k, v);
1866                 return 0;
1867         }
1868         if (!strcmp(k, "pack.deltacachelimit")) {
1869                 cache_max_small_delta_size = git_config_int(k, v);
1870                 return 0;
1871         }
1872         if (!strcmp(k, "pack.threads")) {
1873                 delta_search_threads = git_config_int(k, v);
1874                 if (delta_search_threads < 0)
1875                         die("invalid number of threads specified (%d)",
1876                             delta_search_threads);
1877 #ifdef NO_PTHREADS
1878                 if (delta_search_threads != 1)
1879                         warning("no threads support, ignoring %s", k);
1880 #endif
1881                 return 0;
1882         }
1883         if (!strcmp(k, "pack.indexversion")) {
1884                 pack_idx_opts.version = git_config_int(k, v);
1885                 if (pack_idx_opts.version > 2)
1886                         die("bad pack.indexversion=%"PRIu32,
1887                             pack_idx_opts.version);
1888                 return 0;
1889         }
1890         if (!strcmp(k, "pack.packsizelimit")) {
1891                 pack_size_limit_cfg = git_config_ulong(k, v);
1892                 return 0;
1893         }
1894         return git_default_config(k, v, cb);
1895 }
1896
1897 static void read_object_list_from_stdin(void)
1898 {
1899         char line[40 + 1 + PATH_MAX + 2];
1900         unsigned char sha1[20];
1901
1902         for (;;) {
1903                 if (!fgets(line, sizeof(line), stdin)) {
1904                         if (feof(stdin))
1905                                 break;
1906                         if (!ferror(stdin))
1907                                 die("fgets returned NULL, not EOF, not error!");
1908                         if (errno != EINTR)
1909                                 die_errno("fgets");
1910                         clearerr(stdin);
1911                         continue;
1912                 }
1913                 if (line[0] == '-') {
1914                         if (get_sha1_hex(line+1, sha1))
1915                                 die("expected edge sha1, got garbage:\n %s",
1916                                     line);
1917                         add_preferred_base(sha1);
1918                         continue;
1919                 }
1920                 if (get_sha1_hex(line, sha1))
1921                         die("expected sha1, got garbage:\n %s", line);
1922
1923                 add_preferred_base_object(line+41);
1924                 add_object_entry(sha1, 0, line+41, 0);
1925         }
1926 }
1927
1928 #define OBJECT_ADDED (1u<<20)
1929
1930 static void show_commit(struct commit *commit, void *data)
1931 {
1932         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1933         commit->object.flags |= OBJECT_ADDED;
1934 }
1935
1936 static void show_object(struct object *obj, const struct name_path *path, const char *last)
1937 {
1938         char *name = path_name(path, last);
1939
1940         add_preferred_base_object(name);
1941         add_object_entry(obj->sha1, obj->type, name, 0);
1942         obj->flags |= OBJECT_ADDED;
1943
1944         /*
1945          * We will have generated the hash from the name,
1946          * but not saved a pointer to it - we can free it
1947          */
1948         free((char *)name);
1949 }
1950
1951 static void show_edge(struct commit *commit)
1952 {
1953         add_preferred_base(commit->object.sha1);
1954 }
1955
1956 struct in_pack_object {
1957         off_t offset;
1958         struct object *object;
1959 };
1960
1961 struct in_pack {
1962         int alloc;
1963         int nr;
1964         struct in_pack_object *array;
1965 };
1966
1967 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1968 {
1969         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1970         in_pack->array[in_pack->nr].object = object;
1971         in_pack->nr++;
1972 }
1973
1974 /*
1975  * Compare the objects in the offset order, in order to emulate the
1976  * "git rev-list --objects" output that produced the pack originally.
1977  */
1978 static int ofscmp(const void *a_, const void *b_)
1979 {
1980         struct in_pack_object *a = (struct in_pack_object *)a_;
1981         struct in_pack_object *b = (struct in_pack_object *)b_;
1982
1983         if (a->offset < b->offset)
1984                 return -1;
1985         else if (a->offset > b->offset)
1986                 return 1;
1987         else
1988                 return hashcmp(a->object->sha1, b->object->sha1);
1989 }
1990
1991 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1992 {
1993         struct packed_git *p;
1994         struct in_pack in_pack;
1995         uint32_t i;
1996
1997         memset(&in_pack, 0, sizeof(in_pack));
1998
1999         for (p = packed_git; p; p = p->next) {
2000                 const unsigned char *sha1;
2001                 struct object *o;
2002
2003                 if (!p->pack_local || p->pack_keep)
2004                         continue;
2005                 if (open_pack_index(p))
2006                         die("cannot open pack index");
2007
2008                 ALLOC_GROW(in_pack.array,
2009                            in_pack.nr + p->num_objects,
2010                            in_pack.alloc);
2011
2012                 for (i = 0; i < p->num_objects; i++) {
2013                         sha1 = nth_packed_object_sha1(p, i);
2014                         o = lookup_unknown_object(sha1);
2015                         if (!(o->flags & OBJECT_ADDED))
2016                                 mark_in_pack_object(o, p, &in_pack);
2017                         o->flags |= OBJECT_ADDED;
2018                 }
2019         }
2020
2021         if (in_pack.nr) {
2022                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
2023                       ofscmp);
2024                 for (i = 0; i < in_pack.nr; i++) {
2025                         struct object *o = in_pack.array[i].object;
2026                         add_object_entry(o->sha1, o->type, "", 0);
2027                 }
2028         }
2029         free(in_pack.array);
2030 }
2031
2032 static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2033 {
2034         static struct packed_git *last_found = (void *)1;
2035         struct packed_git *p;
2036
2037         p = (last_found != (void *)1) ? last_found : packed_git;
2038
2039         while (p) {
2040                 if ((!p->pack_local || p->pack_keep) &&
2041                         find_pack_entry_one(sha1, p)) {
2042                         last_found = p;
2043                         return 1;
2044                 }
2045                 if (p == last_found)
2046                         p = packed_git;
2047                 else
2048                         p = p->next;
2049                 if (p == last_found)
2050                         p = p->next;
2051         }
2052         return 0;
2053 }
2054
2055 static void loosen_unused_packed_objects(struct rev_info *revs)
2056 {
2057         struct packed_git *p;
2058         uint32_t i;
2059         const unsigned char *sha1;
2060
2061         for (p = packed_git; p; p = p->next) {
2062                 if (!p->pack_local || p->pack_keep)
2063                         continue;
2064
2065                 if (open_pack_index(p))
2066                         die("cannot open pack index");
2067
2068                 for (i = 0; i < p->num_objects; i++) {
2069                         sha1 = nth_packed_object_sha1(p, i);
2070                         if (!locate_object_entry(sha1) &&
2071                                 !has_sha1_pack_kept_or_nonlocal(sha1))
2072                                 if (force_object_loose(sha1, p->mtime))
2073                                         die("unable to force loose object");
2074                 }
2075         }
2076 }
2077
2078 static void get_object_list(int ac, const char **av)
2079 {
2080         struct rev_info revs;
2081         char line[1000];
2082         int flags = 0;
2083
2084         init_revisions(&revs, NULL);
2085         save_commit_buffer = 0;
2086         setup_revisions(ac, av, &revs, NULL);
2087
2088         while (fgets(line, sizeof(line), stdin) != NULL) {
2089                 int len = strlen(line);
2090                 if (len && line[len - 1] == '\n')
2091                         line[--len] = 0;
2092                 if (!len)
2093                         break;
2094                 if (*line == '-') {
2095                         if (!strcmp(line, "--not")) {
2096                                 flags ^= UNINTERESTING;
2097                                 continue;
2098                         }
2099                         die("not a rev '%s'", line);
2100                 }
2101                 if (handle_revision_arg(line, &revs, flags, 1))
2102                         die("bad revision '%s'", line);
2103         }
2104
2105         if (prepare_revision_walk(&revs))
2106                 die("revision walk setup failed");
2107         mark_edges_uninteresting(revs.commits, &revs, show_edge);
2108         traverse_commit_list(&revs, show_commit, show_object, NULL);
2109
2110         if (keep_unreachable)
2111                 add_objects_in_unpacked_packs(&revs);
2112         if (unpack_unreachable)
2113                 loosen_unused_packed_objects(&revs);
2114 }
2115
2116 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2117 {
2118         int use_internal_rev_list = 0;
2119         int thin = 0;
2120         int all_progress_implied = 0;
2121         uint32_t i;
2122         const char **rp_av;
2123         int rp_ac_alloc = 64;
2124         int rp_ac;
2125
2126         read_replace_refs = 0;
2127
2128         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2129
2130         rp_av[0] = "pack-objects";
2131         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2132         rp_ac = 2;
2133
2134         reset_pack_idx_option(&pack_idx_opts);
2135         git_config(git_pack_config, NULL);
2136         if (!pack_compression_seen && core_compression_seen)
2137                 pack_compression_level = core_compression_level;
2138
2139         progress = isatty(2);
2140         for (i = 1; i < argc; i++) {
2141                 const char *arg = argv[i];
2142
2143                 if (*arg != '-')
2144                         break;
2145
2146                 if (!strcmp("--non-empty", arg)) {
2147                         non_empty = 1;
2148                         continue;
2149                 }
2150                 if (!strcmp("--local", arg)) {
2151                         local = 1;
2152                         continue;
2153                 }
2154                 if (!strcmp("--incremental", arg)) {
2155                         incremental = 1;
2156                         continue;
2157                 }
2158                 if (!strcmp("--honor-pack-keep", arg)) {
2159                         ignore_packed_keep = 1;
2160                         continue;
2161                 }
2162                 if (!prefixcmp(arg, "--compression=")) {
2163                         char *end;
2164                         int level = strtoul(arg+14, &end, 0);
2165                         if (!arg[14] || *end)
2166                                 usage(pack_usage);
2167                         if (level == -1)
2168                                 level = Z_DEFAULT_COMPRESSION;
2169                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2170                                 die("bad pack compression level %d", level);
2171                         pack_compression_level = level;
2172                         continue;
2173                 }
2174                 if (!prefixcmp(arg, "--max-pack-size=")) {
2175                         pack_size_limit_cfg = 0;
2176                         if (!git_parse_ulong(arg+16, &pack_size_limit))
2177                                 usage(pack_usage);
2178                         continue;
2179                 }
2180                 if (!prefixcmp(arg, "--window=")) {
2181                         char *end;
2182                         window = strtoul(arg+9, &end, 0);
2183                         if (!arg[9] || *end)
2184                                 usage(pack_usage);
2185                         continue;
2186                 }
2187                 if (!prefixcmp(arg, "--window-memory=")) {
2188                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2189                                 usage(pack_usage);
2190                         continue;
2191                 }
2192                 if (!prefixcmp(arg, "--threads=")) {
2193                         char *end;
2194                         delta_search_threads = strtoul(arg+10, &end, 0);
2195                         if (!arg[10] || *end || delta_search_threads < 0)
2196                                 usage(pack_usage);
2197 #ifdef NO_PTHREADS
2198                         if (delta_search_threads != 1)
2199                                 warning("no threads support, "
2200                                         "ignoring %s", arg);
2201 #endif
2202                         continue;
2203                 }
2204                 if (!prefixcmp(arg, "--depth=")) {
2205                         char *end;
2206                         depth = strtoul(arg+8, &end, 0);
2207                         if (!arg[8] || *end)
2208                                 usage(pack_usage);
2209                         continue;
2210                 }
2211                 if (!strcmp("--progress", arg)) {
2212                         progress = 1;
2213                         continue;
2214                 }
2215                 if (!strcmp("--all-progress", arg)) {
2216                         progress = 2;
2217                         continue;
2218                 }
2219                 if (!strcmp("--all-progress-implied", arg)) {
2220                         all_progress_implied = 1;
2221                         continue;
2222                 }
2223                 if (!strcmp("-q", arg)) {
2224                         progress = 0;
2225                         continue;
2226                 }
2227                 if (!strcmp("--no-reuse-delta", arg)) {
2228                         reuse_delta = 0;
2229                         continue;
2230                 }
2231                 if (!strcmp("--no-reuse-object", arg)) {
2232                         reuse_object = reuse_delta = 0;
2233                         continue;
2234                 }
2235                 if (!strcmp("--delta-base-offset", arg)) {
2236                         allow_ofs_delta = 1;
2237                         continue;
2238                 }
2239                 if (!strcmp("--stdout", arg)) {
2240                         pack_to_stdout = 1;
2241                         continue;
2242                 }
2243                 if (!strcmp("--revs", arg)) {
2244                         use_internal_rev_list = 1;
2245                         continue;
2246                 }
2247                 if (!strcmp("--keep-unreachable", arg)) {
2248                         keep_unreachable = 1;
2249                         continue;
2250                 }
2251                 if (!strcmp("--unpack-unreachable", arg)) {
2252                         unpack_unreachable = 1;
2253                         continue;
2254                 }
2255                 if (!strcmp("--include-tag", arg)) {
2256                         include_tag = 1;
2257                         continue;
2258                 }
2259                 if (!strcmp("--unpacked", arg) ||
2260                     !strcmp("--reflog", arg) ||
2261                     !strcmp("--all", arg)) {
2262                         use_internal_rev_list = 1;
2263                         if (rp_ac >= rp_ac_alloc - 1) {
2264                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2265                                 rp_av = xrealloc(rp_av,
2266                                                  rp_ac_alloc * sizeof(*rp_av));
2267                         }
2268                         rp_av[rp_ac++] = arg;
2269                         continue;
2270                 }
2271                 if (!strcmp("--thin", arg)) {
2272                         use_internal_rev_list = 1;
2273                         thin = 1;
2274                         rp_av[1] = "--objects-edge";
2275                         continue;
2276                 }
2277                 if (!prefixcmp(arg, "--index-version=")) {
2278                         char *c;
2279                         pack_idx_opts.version = strtoul(arg + 16, &c, 10);
2280                         if (pack_idx_opts.version > 2)
2281                                 die("bad %s", arg);
2282                         if (*c == ',')
2283                                 pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
2284                         if (*c || pack_idx_opts.off32_limit & 0x80000000)
2285                                 die("bad %s", arg);
2286                         continue;
2287                 }
2288                 if (!strcmp(arg, "--keep-true-parents")) {
2289                         grafts_replace_parents = 0;
2290                         continue;
2291                 }
2292                 usage(pack_usage);
2293         }
2294
2295         /* Traditionally "pack-objects [options] base extra" failed;
2296          * we would however want to take refs parameter that would
2297          * have been given to upstream rev-list ourselves, which means
2298          * we somehow want to say what the base name is.  So the
2299          * syntax would be:
2300          *
2301          * pack-objects [options] base <refs...>
2302          *
2303          * in other words, we would treat the first non-option as the
2304          * base_name and send everything else to the internal revision
2305          * walker.
2306          */
2307
2308         if (!pack_to_stdout)
2309                 base_name = argv[i++];
2310
2311         if (pack_to_stdout != !base_name)
2312                 usage(pack_usage);
2313
2314         if (!pack_to_stdout && !pack_size_limit)
2315                 pack_size_limit = pack_size_limit_cfg;
2316         if (pack_to_stdout && pack_size_limit)
2317                 die("--max-pack-size cannot be used to build a pack for transfer.");
2318         if (pack_size_limit && pack_size_limit < 1024*1024) {
2319                 warning("minimum pack size limit is 1 MiB");
2320                 pack_size_limit = 1024*1024;
2321         }
2322
2323         if (!pack_to_stdout && thin)
2324                 die("--thin cannot be used to build an indexable pack.");
2325
2326         if (keep_unreachable && unpack_unreachable)
2327                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2328
2329         if (progress && all_progress_implied)
2330                 progress = 2;
2331
2332         prepare_packed_git();
2333
2334         if (progress)
2335                 progress_state = start_progress("Counting objects", 0);
2336         if (!use_internal_rev_list)
2337                 read_object_list_from_stdin();
2338         else {
2339                 rp_av[rp_ac] = NULL;
2340                 get_object_list(rp_ac, rp_av);
2341         }
2342         cleanup_preferred_base();
2343         if (include_tag && nr_result)
2344                 for_each_ref(add_ref_tag, NULL);
2345         stop_progress(&progress_state);
2346
2347         if (non_empty && !nr_result)
2348                 return 0;
2349         if (nr_result)
2350                 prepare_pack(window, depth);
2351         write_pack_file();
2352         if (progress)
2353                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2354                         " reused %"PRIu32" (delta %"PRIu32")\n",
2355                         written, written_delta, reused, reused_delta);
2356         return 0;
2357 }