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
  20 #ifndef NO_PTHREADS
  21 #include "thread-utils.h"
  22 #include <pthread.h>
  23 #endif
  24
  25 static const char pack_usage[] =
  26   "git pack-objects [{ -q | --progress | --all-progress }]\n"
  27   "        [--all-progress-implied]\n"
  28   "        [--max-pack-size=N] [--local] [--incremental]\n"
  29   "        [--window=N] [--window-memory=N] [--depth=N]\n"
  30   "        [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset]\n"
  31   "        [--threads=N] [--non-empty] [--revs [--unpacked | --all]*]\n"
  32   "        [--reflog] [--stdout | base-name] [--include-tag]\n"
  33   "        [--keep-unreachable | --unpack-unreachable \n"
  34   "        [<ref-list | <object-list]";
  35
  36 struct object_entry {
  37         struct pack_idx_entry idx;
  38         unsigned long size;     /* uncompressed size */
  39         struct packed_git *in_pack;     /* already in pack */
  40         off_t in_pack_offset;
  41         struct object_entry *delta;     /* delta base object */
  42         struct object_entry *delta_child; /* deltified objects who bases me */
  43         struct object_entry *delta_sibling; /* other deltified objects who
  44                                              * uses the same base as me
  45                                              */
  46         void *delta_data;       /* cached delta (uncompressed) */
  47         unsigned long delta_size;       /* delta data size (uncompressed) */
  48         unsigned long z_delta_size;     /* delta data size (compressed) */
  49         unsigned int hash;      /* name hint hash */
  50         enum object_type type;
  51         enum object_type in_pack_type;  /* could be delta */
  52         unsigned char in_pack_header_size;
  53         unsigned char preferred_base; /* we do not pack this, but is available
  54                                        * to be used as the base object to delta
  55                                        * objects against.
  56                                        */
  57         unsigned char no_try_delta;
  58 };
  59
  60 /*
  61  * Objects we are going to pack are collected in objects array (dynamically
  62  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  63  * in the order we see -- typically rev-list --objects order that gives us
  64  * nice "minimum seek" order.
  65  */
  66 static struct object_entry *objects;
  67 static struct pack_idx_entry **written_list;
  68 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
  69
  70 static int non_empty;
  71 static int reuse_delta = 1, reuse_object = 1;
  72 static int keep_unreachable, unpack_unreachable, include_tag;
  73 static int local;
  74 static int incremental;
  75 static int ignore_packed_keep;
  76 static int allow_ofs_delta;
  77 static const char *base_name;
  78 static int progress = 1;
  79 static int window = 10;
  80 static unsigned long pack_size_limit, pack_size_limit_cfg;
  81 static int depth = 50;
  82 static int delta_search_threads;
  83 static int pack_to_stdout;
  84 static int num_preferred_base;
  85 static struct progress *progress_state;
  86 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  87 static int pack_compression_seen;
  88
  89 static unsigned long delta_cache_size = 0;
  90 static unsigned long max_delta_cache_size = 256 * 1024 * 1024;
  91 static unsigned long cache_max_small_delta_size = 1000;
  92
  93 static unsigned long window_memory_limit = 0;
  94
  95 /*
  96  * The object names in objects array are hashed with this hashtable,
  97  * to help looking up the entry by object name.
  98  * This hashtable is built after all the objects are seen.
  99  */
 100 static int *object_ix;
 101 static int object_ix_hashsz;
 102
 103 /*
 104  * stats
 105  */
 106 static uint32_t written, written_delta;
 107 static uint32_t reused, reused_delta;
 108
 109
 110 static void *get_delta(struct object_entry *entry)
 111 {
 112         unsigned long size, base_size, delta_size;
 113         void *buf, *base_buf, *delta_buf;
 114         enum object_type type;
 115
 116         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 117         if (!buf)
 118                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 119         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
 120         if (!base_buf)
 121                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 122         delta_buf = diff_delta(base_buf, base_size,
 123                                buf, size, &delta_size, 0);
 124         if (!delta_buf || delta_size != entry->delta_size)
 125                 die("delta size changed");
 126         free(buf);
 127         free(base_buf);
 128         return delta_buf;
 129 }
 130
 131 static unsigned long do_compress(void **pptr, unsigned long size)
 132 {
 133         z_stream stream;
 134         void *in, *out;
 135         unsigned long maxsize;
 136
 137         memset(&stream, 0, sizeof(stream));
 138         deflateInit(&stream, pack_compression_level);
 139         maxsize = deflateBound(&stream, size);
 140
 141         in = *pptr;
 142         out = xmalloc(maxsize);
 143         *pptr = out;
 144
 145         stream.next_in = in;
 146         stream.avail_in = size;
 147         stream.next_out = out;
 148         stream.avail_out = maxsize;
 149         while (deflate(&stream, Z_FINISH) == Z_OK)
 150                 ; /* nothing */
 151         deflateEnd(&stream);
 152
 153         free(in);
 154         return stream.total_out;
 155 }
 156
 157 /*
 158  * The per-object header is a pretty dense thing, which is
 159  *  - first byte: low four bits are "size", then three bits of "type",
 160  *    and the high bit is "size continues".
 161  *  - each byte afterwards: low seven bits are size continuation,
 162  *    with the high bit being "size continues"
 163  */
 164 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 165 {
 166         int n = 1;
 167         unsigned char c;
 168
 169         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 170                 die("bad type %d", type);
 171
 172         c = (type << 4) | (size & 15);
 173         size >>= 4;
 174         while (size) {
 175                 *hdr++ = c | 0x80;
 176                 c = size & 0x7f;
 177                 size >>= 7;
 178                 n++;
 179         }
 180         *hdr = c;
 181         return n;
 182 }
 183
 184 /*
 185  * we are going to reuse the existing object data as is.  make
 186  * sure it is not corrupt.
 187  */
 188 static int check_pack_inflate(struct packed_git *p,
 189                 struct pack_window **w_curs,
 190                 off_t offset,
 191                 off_t len,
 192                 unsigned long expect)
 193 {
 194         z_stream stream;
 195         unsigned char fakebuf[4096], *in;
 196         int st;
 197
 198         memset(&stream, 0, sizeof(stream));
 199         git_inflate_init(&stream);
 200         do {
 201                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 202                 stream.next_in = in;
 203                 stream.next_out = fakebuf;
 204                 stream.avail_out = sizeof(fakebuf);
 205                 st = git_inflate(&stream, Z_FINISH);
 206                 offset += stream.next_in - in;
 207         } while (st == Z_OK || st == Z_BUF_ERROR);
 208         git_inflate_end(&stream);
 209         return (st == Z_STREAM_END &&
 210                 stream.total_out == expect &&
 211                 stream.total_in == len) ? 0 : -1;
 212 }
 213
 214 static void copy_pack_data(struct sha1file *f,
 215                 struct packed_git *p,
 216                 struct pack_window **w_curs,
 217                 off_t offset,
 218                 off_t len)
 219 {
 220         unsigned char *in;
 221         unsigned int avail;
 222
 223         while (len) {
 224                 in = use_pack(p, w_curs, offset, &avail);
 225                 if (avail > len)
 226                         avail = (unsigned int)len;
 227                 sha1write(f, in, avail);
 228                 offset += avail;
 229                 len -= avail;
 230         }
 231 }
 232
 233 static unsigned long write_object(struct sha1file *f,
 234                                   struct object_entry *entry,
 235                                   off_t write_offset)
 236 {
 237         unsigned long size, limit, datalen;
 238         void *buf;
 239         unsigned char header[10], dheader[10];
 240         unsigned hdrlen;
 241         enum object_type type;
 242         int usable_delta, to_reuse;
 243
 244         if (!pack_to_stdout)
 245                 crc32_begin(f);
 246
 247         type = entry->type;
 248
 249         /* apply size limit if limited packsize and not first object */
 250         if (!pack_size_limit || !nr_written)
 251                 limit = 0;
 252         else if (pack_size_limit <= write_offset)
 253                 /*
 254                  * the earlier object did not fit the limit; avoid
 255                  * mistaking this with unlimited (i.e. limit = 0).
 256                  */
 257                 limit = 1;
 258         else
 259                 limit = pack_size_limit - write_offset;
 260
 261         if (!entry->delta)
 262                 usable_delta = 0;       /* no delta */
 263         else if (!pack_size_limit)
 264                usable_delta = 1;        /* unlimited packfile */
 265         else if (entry->delta->idx.offset == (off_t)-1)
 266                 usable_delta = 0;       /* base was written to another pack */
 267         else if (entry->delta->idx.offset)
 268                 usable_delta = 1;       /* base already exists in this pack */
 269         else
 270                 usable_delta = 0;       /* base could end up in another pack */
 271
 272         if (!reuse_object)
 273                 to_reuse = 0;   /* explicit */
 274         else if (!entry->in_pack)
 275                 to_reuse = 0;   /* can't reuse what we don't have */
 276         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
 277                                 /* check_object() decided it for us ... */
 278                 to_reuse = usable_delta;
 279                                 /* ... but pack split may override that */
 280         else if (type != entry->in_pack_type)
 281                 to_reuse = 0;   /* pack has delta which is unusable */
 282         else if (entry->delta)
 283                 to_reuse = 0;   /* we want to pack afresh */
 284         else
 285                 to_reuse = 1;   /* we have it in-pack undeltified,
 286                                  * and we do not need to deltify it.
 287                                  */
 288
 289         if (!to_reuse) {
 290                 no_reuse:
 291                 if (!usable_delta) {
 292                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 293                         if (!buf)
 294                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 295                         /*
 296                          * make sure no cached delta data remains from a
 297                          * previous attempt before a pack split occurred.
 298                          */
 299                         free(entry->delta_data);
 300                         entry->delta_data = NULL;
 301                         entry->z_delta_size = 0;
 302                 } else if (entry->delta_data) {
 303                         size = entry->delta_size;
 304                         buf = entry->delta_data;
 305                         entry->delta_data = NULL;
 306                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 307                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 308                 } else {
 309                         buf = get_delta(entry);
 310                         size = entry->delta_size;
 311                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 312                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 313                 }
 314
 315                 if (entry->z_delta_size)
 316                         datalen = entry->z_delta_size;
 317                 else
 318                         datalen = do_compress(&buf, size);
 319
 320                 /*
 321                  * The object header is a byte of 'type' followed by zero or
 322                  * more bytes of length.
 323                  */
 324                 hdrlen = encode_header(type, size, header);
 325
 326                 if (type == OBJ_OFS_DELTA) {
 327                         /*
 328                          * Deltas with relative base contain an additional
 329                          * encoding of the relative offset for the delta
 330                          * base from this object's position in the pack.
 331                          */
 332                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 333                         unsigned pos = sizeof(dheader) - 1;
 334                         dheader[pos] = ofs & 127;
 335                         while (ofs >>= 7)
 336                                 dheader[--pos] = 128 | (--ofs & 127);
 337                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 338                                 free(buf);
 339                                 return 0;
 340                         }
 341                         sha1write(f, header, hdrlen);
 342                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 343                         hdrlen += sizeof(dheader) - pos;
 344                 } else if (type == OBJ_REF_DELTA) {
 345                         /*
 346                          * Deltas with a base reference contain
 347                          * an additional 20 bytes for the base sha1.
 348                          */
 349                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 350                                 free(buf);
 351                                 return 0;
 352                         }
 353                         sha1write(f, header, hdrlen);
 354                         sha1write(f, entry->delta->idx.sha1, 20);
 355                         hdrlen += 20;
 356                 } else {
 357                         if (limit && hdrlen + datalen + 20 >= limit) {
 358                                 free(buf);
 359                                 return 0;
 360                         }
 361                         sha1write(f, header, hdrlen);
 362                 }
 363                 sha1write(f, buf, datalen);
 364                 free(buf);
 365         }
 366         else {
 367                 struct packed_git *p = entry->in_pack;
 368                 struct pack_window *w_curs = NULL;
 369                 struct revindex_entry *revidx;
 370                 off_t offset;
 371
 372                 if (entry->delta)
 373                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 374                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 375                 hdrlen = encode_header(type, entry->size, header);
 376
 377                 offset = entry->in_pack_offset;
 378                 revidx = find_pack_revindex(p, offset);
 379                 datalen = revidx[1].offset - offset;
 380                 if (!pack_to_stdout && p->index_version > 1 &&
 381                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 382                         error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 383                         unuse_pack(&w_curs);
 384                         goto no_reuse;
 385                 }
 386
 387                 offset += entry->in_pack_header_size;
 388                 datalen -= entry->in_pack_header_size;
 389                 if (!pack_to_stdout && p->index_version == 1 &&
 390                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
 391                         error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 392                         unuse_pack(&w_curs);
 393                         goto no_reuse;
 394                 }
 395
 396                 if (type == OBJ_OFS_DELTA) {
 397                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 398                         unsigned pos = sizeof(dheader) - 1;
 399                         dheader[pos] = ofs & 127;
 400                         while (ofs >>= 7)
 401                                 dheader[--pos] = 128 | (--ofs & 127);
 402                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 403                                 unuse_pack(&w_curs);
 404                                 return 0;
 405                         }
 406                         sha1write(f, header, hdrlen);
 407                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 408                         hdrlen += sizeof(dheader) - pos;
 409                         reused_delta++;
 410                 } else if (type == OBJ_REF_DELTA) {
 411                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 412                                 unuse_pack(&w_curs);
 413                                 return 0;
 414                         }
 415                         sha1write(f, header, hdrlen);
 416                         sha1write(f, entry->delta->idx.sha1, 20);
 417                         hdrlen += 20;
 418                         reused_delta++;
 419                 } else {
 420                         if (limit && hdrlen + datalen + 20 >= limit) {
 421                                 unuse_pack(&w_curs);
 422                                 return 0;
 423                         }
 424                         sha1write(f, header, hdrlen);
 425                 }
 426                 copy_pack_data(f, p, &w_curs, offset, datalen);
 427                 unuse_pack(&w_curs);
 428                 reused++;
 429         }
 430         if (usable_delta)
 431                 written_delta++;
 432         written++;
 433         if (!pack_to_stdout)
 434                 entry->idx.crc32 = crc32_end(f);
 435         return hdrlen + datalen;
 436 }
 437
 438 static int write_one(struct sha1file *f,
 439                                struct object_entry *e,
 440                                off_t *offset)
 441 {
 442         unsigned long size;
 443
 444         /* offset is non zero if object is written already. */
 445         if (e->idx.offset || e->preferred_base)
 446                 return -1;
 447
 448         /* if we are deltified, write out base object first. */
 449         if (e->delta && !write_one(f, e->delta, offset))
 450                 return 0;
 451
 452         e->idx.offset = *offset;
 453         size = write_object(f, e, *offset);
 454         if (!size) {
 455                 e->idx.offset = 0;
 456                 return 0;
 457         }
 458         written_list[nr_written++] = &e->idx;
 459
 460         /* make sure off_t is sufficiently large not to wrap */
 461         if (*offset > *offset + size)
 462                 die("pack too large for current definition of off_t");
 463         *offset += size;
 464         return 1;
 465 }
 466
 467 /* forward declaration for write_pack_file */
 468 static int adjust_perm(const char *path, mode_t mode);
 469
 470 static void write_pack_file(void)
 471 {
 472         uint32_t i = 0, j;
 473         struct sha1file *f;
 474         off_t offset;
 475         struct pack_header hdr;
 476         uint32_t nr_remaining = nr_result;
 477         time_t last_mtime = 0;
 478
 479         if (progress > pack_to_stdout)
 480                 progress_state = start_progress("Writing objects", nr_result);
 481         written_list = xmalloc(nr_objects * sizeof(*written_list));
 482
 483         do {
 484                 unsigned char sha1[20];
 485                 char *pack_tmp_name = NULL;
 486
 487                 if (pack_to_stdout) {
 488                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 489                 } else {
 490                         char tmpname[PATH_MAX];
 491                         int fd;
 492                         fd = odb_mkstemp(tmpname, sizeof(tmpname),
 493                                          "pack/tmp_pack_XXXXXX");
 494                         pack_tmp_name = xstrdup(tmpname);
 495                         f = sha1fd(fd, pack_tmp_name);
 496                 }
 497
 498                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
 499                 hdr.hdr_version = htonl(PACK_VERSION);
 500                 hdr.hdr_entries = htonl(nr_remaining);
 501                 sha1write(f, &hdr, sizeof(hdr));
 502                 offset = sizeof(hdr);
 503                 nr_written = 0;
 504                 for (; i < nr_objects; i++) {
 505                         if (!write_one(f, objects + i, &offset))
 506                                 break;
 507                         display_progress(progress_state, written);
 508                 }
 509
 510                 /*
 511                  * Did we write the wrong # entries in the header?
 512                  * If so, rewrite it like in fast-import
 513                  */
 514                 if (pack_to_stdout) {
 515                         sha1close(f, sha1, CSUM_CLOSE);
 516                 } else if (nr_written == nr_remaining) {
 517                         sha1close(f, sha1, CSUM_FSYNC);
 518                 } else {
 519                         int fd = sha1close(f, sha1, 0);
 520                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
 521                                                  nr_written, sha1, offset);
 522                         close(fd);
 523                 }
 524
 525                 if (!pack_to_stdout) {
 526                         mode_t mode = umask(0);
 527                         struct stat st;
 528                         const char *idx_tmp_name;
 529                         char tmpname[PATH_MAX];
 530
 531                         umask(mode);
 532                         mode = 0444 & ~mode;
 533
 534                         idx_tmp_name = write_idx_file(NULL, written_list,
 535                                                       nr_written, sha1);
 536
 537                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 538                                  base_name, sha1_to_hex(sha1));
 539                         free_pack_by_name(tmpname);
 540                         if (adjust_perm(pack_tmp_name, mode))
 541                                 die_errno("unable to make temporary pack file readable");
 542                         if (rename(pack_tmp_name, tmpname))
 543                                 die_errno("unable to rename temporary pack file");
 544
 545                         /*
 546                          * Packs are runtime accessed in their mtime
 547                          * order since newer packs are more likely to contain
 548                          * younger objects.  So if we are creating multiple
 549                          * packs then we should modify the mtime of later ones
 550                          * to preserve this property.
 551                          */
 552                         if (stat(tmpname, &st) < 0) {
 553                                 warning("failed to stat %s: %s",
 554                                         tmpname, strerror(errno));
 555                         } else if (!last_mtime) {
 556                                 last_mtime = st.st_mtime;
 557                         } else {
 558                                 struct utimbuf utb;
 559                                 utb.actime = st.st_atime;
 560                                 utb.modtime = --last_mtime;
 561                                 if (utime(tmpname, &utb) < 0)
 562                                         warning("failed utime() on %s: %s",
 563                                                 tmpname, strerror(errno));
 564                         }
 565
 566                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 567                                  base_name, sha1_to_hex(sha1));
 568                         if (adjust_perm(idx_tmp_name, mode))
 569                                 die_errno("unable to make temporary index file readable");
 570                         if (rename(idx_tmp_name, tmpname))
 571                                 die_errno("unable to rename temporary index file");
 572
 573                         free((void *) idx_tmp_name);
 574                         free(pack_tmp_name);
 575                         puts(sha1_to_hex(sha1));
 576                 }
 577
 578                 /* mark written objects as written to previous pack */
 579                 for (j = 0; j < nr_written; j++) {
 580                         written_list[j]->offset = (off_t)-1;
 581                 }
 582                 nr_remaining -= nr_written;
 583         } while (nr_remaining && i < nr_objects);
 584
 585         free(written_list);
 586         stop_progress(&progress_state);
 587         if (written != nr_result)
 588                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
 589                         written, nr_result);
 590 }
 591
 592 static int locate_object_entry_hash(const unsigned char *sha1)
 593 {
 594         int i;
 595         unsigned int ui;
 596         memcpy(&ui, sha1, sizeof(unsigned int));
 597         i = ui % object_ix_hashsz;
 598         while (0 < object_ix[i]) {
 599                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 600                         return i;
 601                 if (++i == object_ix_hashsz)
 602                         i = 0;
 603         }
 604         return -1 - i;
 605 }
 606
 607 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 608 {
 609         int i;
 610
 611         if (!object_ix_hashsz)
 612                 return NULL;
 613
 614         i = locate_object_entry_hash(sha1);
 615         if (0 <= i)
 616                 return &objects[object_ix[i]-1];
 617         return NULL;
 618 }
 619
 620 static void rehash_objects(void)
 621 {
 622         uint32_t i;
 623         struct object_entry *oe;
 624
 625         object_ix_hashsz = nr_objects * 3;
 626         if (object_ix_hashsz < 1024)
 627                 object_ix_hashsz = 1024;
 628         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 629         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 630         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 631                 int ix = locate_object_entry_hash(oe->idx.sha1);
 632                 if (0 <= ix)
 633                         continue;
 634                 ix = -1 - ix;
 635                 object_ix[ix] = i + 1;
 636         }
 637 }
 638
 639 static unsigned name_hash(const char *name)
 640 {
 641         unsigned c, hash = 0;
 642
 643         if (!name)
 644                 return 0;
 645
 646         /*
 647          * This effectively just creates a sortable number from the
 648          * last sixteen non-whitespace characters. Last characters
 649          * count "most", so things that end in ".c" sort together.
 650          */
 651         while ((c = *name++) != 0) {
 652                 if (isspace(c))
 653                         continue;
 654                 hash = (hash >> 2) + (c << 24);
 655         }
 656         return hash;
 657 }
 658
 659 static void setup_delta_attr_check(struct git_attr_check *check)
 660 {
 661         static struct git_attr *attr_delta;
 662
 663         if (!attr_delta)
 664                 attr_delta = git_attr("delta");
 665
 666         check[0].attr = attr_delta;
 667 }
 668
 669 static int no_try_delta(const char *path)
 670 {
 671         struct git_attr_check check[1];
 672
 673         setup_delta_attr_check(check);
 674         if (git_checkattr(path, ARRAY_SIZE(check), check))
 675                 return 0;
 676         if (ATTR_FALSE(check->value))
 677                 return 1;
 678         return 0;
 679 }
 680
 681 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 682                             const char *name, int exclude)
 683 {
 684         struct object_entry *entry;
 685         struct packed_git *p, *found_pack = NULL;
 686         off_t found_offset = 0;
 687         int ix;
 688         unsigned hash = name_hash(name);
 689
 690         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 691         if (ix >= 0) {
 692                 if (exclude) {
 693                         entry = objects + object_ix[ix] - 1;
 694                         if (!entry->preferred_base)
 695                                 nr_result--;
 696                         entry->preferred_base = 1;
 697                 }
 698                 return 0;
 699         }
 700
 701         if (!exclude && local && has_loose_object_nonlocal(sha1))
 702                 return 0;
 703
 704         for (p = packed_git; p; p = p->next) {
 705                 off_t offset = find_pack_entry_one(sha1, p);
 706                 if (offset) {
 707                         if (!found_pack) {
 708                                 found_offset = offset;
 709                                 found_pack = p;
 710                         }
 711                         if (exclude)
 712                                 break;
 713                         if (incremental)
 714                                 return 0;
 715                         if (local && !p->pack_local)
 716                                 return 0;
 717                         if (ignore_packed_keep && p->pack_local && p->pack_keep)
 718                                 return 0;
 719                 }
 720         }
 721
 722         if (nr_objects >= nr_alloc) {
 723                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 724                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 725         }
 726
 727         entry = objects + nr_objects++;
 728         memset(entry, 0, sizeof(*entry));
 729         hashcpy(entry->idx.sha1, sha1);
 730         entry->hash = hash;
 731         if (type)
 732                 entry->type = type;
 733         if (exclude)
 734                 entry->preferred_base = 1;
 735         else
 736                 nr_result++;
 737         if (found_pack) {
 738                 entry->in_pack = found_pack;
 739                 entry->in_pack_offset = found_offset;
 740         }
 741
 742         if (object_ix_hashsz * 3 <= nr_objects * 4)
 743                 rehash_objects();
 744         else
 745                 object_ix[-1 - ix] = nr_objects;
 746
 747         display_progress(progress_state, nr_objects);
 748
 749         if (name && no_try_delta(name))
 750                 entry->no_try_delta = 1;
 751
 752         return 1;
 753 }
 754
 755 struct pbase_tree_cache {
 756         unsigned char sha1[20];
 757         int ref;
 758         int temporary;
 759         void *tree_data;
 760         unsigned long tree_size;
 761 };
 762
 763 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 764 static int pbase_tree_cache_ix(const unsigned char *sha1)
 765 {
 766         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 767 }
 768 static int pbase_tree_cache_ix_incr(int ix)
 769 {
 770         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 771 }
 772
 773 static struct pbase_tree {
 774         struct pbase_tree *next;
 775         /* This is a phony "cache" entry; we are not
 776          * going to evict it nor find it through _get()
 777          * mechanism -- this is for the toplevel node that
 778          * would almost always change with any commit.
 779          */
 780         struct pbase_tree_cache pcache;
 781 } *pbase_tree;
 782
 783 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 784 {
 785         struct pbase_tree_cache *ent, *nent;
 786         void *data;
 787         unsigned long size;
 788         enum object_type type;
 789         int neigh;
 790         int my_ix = pbase_tree_cache_ix(sha1);
 791         int available_ix = -1;
 792
 793         /* pbase-tree-cache acts as a limited hashtable.
 794          * your object will be found at your index or within a few
 795          * slots after that slot if it is cached.
 796          */
 797         for (neigh = 0; neigh < 8; neigh++) {
 798                 ent = pbase_tree_cache[my_ix];
 799                 if (ent && !hashcmp(ent->sha1, sha1)) {
 800                         ent->ref++;
 801                         return ent;
 802                 }
 803                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 804                          ((0 <= available_ix) &&
 805                           (!ent && pbase_tree_cache[available_ix])))
 806                         available_ix = my_ix;
 807                 if (!ent)
 808                         break;
 809                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 810         }
 811
 812         /* Did not find one.  Either we got a bogus request or
 813          * we need to read and perhaps cache.
 814          */
 815         data = read_sha1_file(sha1, &type, &size);
 816         if (!data)
 817                 return NULL;
 818         if (type != OBJ_TREE) {
 819                 free(data);
 820                 return NULL;
 821         }
 822
 823         /* We need to either cache or return a throwaway copy */
 824
 825         if (available_ix < 0)
 826                 ent = NULL;
 827         else {
 828                 ent = pbase_tree_cache[available_ix];
 829                 my_ix = available_ix;
 830         }
 831
 832         if (!ent) {
 833                 nent = xmalloc(sizeof(*nent));
 834                 nent->temporary = (available_ix < 0);
 835         }
 836         else {
 837                 /* evict and reuse */
 838                 free(ent->tree_data);
 839                 nent = ent;
 840         }
 841         hashcpy(nent->sha1, sha1);
 842         nent->tree_data = data;
 843         nent->tree_size = size;
 844         nent->ref = 1;
 845         if (!nent->temporary)
 846                 pbase_tree_cache[my_ix] = nent;
 847         return nent;
 848 }
 849
 850 static void pbase_tree_put(struct pbase_tree_cache *cache)
 851 {
 852         if (!cache->temporary) {
 853                 cache->ref--;
 854                 return;
 855         }
 856         free(cache->tree_data);
 857         free(cache);
 858 }
 859
 860 static int name_cmp_len(const char *name)
 861 {
 862         int i;
 863         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 864                 ;
 865         return i;
 866 }
 867
 868 static void add_pbase_object(struct tree_desc *tree,
 869                              const char *name,
 870                              int cmplen,
 871                              const char *fullname)
 872 {
 873         struct name_entry entry;
 874         int cmp;
 875
 876         while (tree_entry(tree,&entry)) {
 877                 if (S_ISGITLINK(entry.mode))
 878                         continue;
 879                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 880                       memcmp(name, entry.path, cmplen);
 881                 if (cmp > 0)
 882                         continue;
 883                 if (cmp < 0)
 884                         return;
 885                 if (name[cmplen] != '/') {
 886                         add_object_entry(entry.sha1,
 887                                          object_type(entry.mode),
 888                                          fullname, 1);
 889                         return;
 890                 }
 891                 if (S_ISDIR(entry.mode)) {
 892                         struct tree_desc sub;
 893                         struct pbase_tree_cache *tree;
 894                         const char *down = name+cmplen+1;
 895                         int downlen = name_cmp_len(down);
 896
 897                         tree = pbase_tree_get(entry.sha1);
 898                         if (!tree)
 899                                 return;
 900                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 901
 902                         add_pbase_object(&sub, down, downlen, fullname);
 903                         pbase_tree_put(tree);
 904                 }
 905         }
 906 }
 907
 908 static unsigned *done_pbase_paths;
 909 static int done_pbase_paths_num;
 910 static int done_pbase_paths_alloc;
 911 static int done_pbase_path_pos(unsigned hash)
 912 {
 913         int lo = 0;
 914         int hi = done_pbase_paths_num;
 915         while (lo < hi) {
 916                 int mi = (hi + lo) / 2;
 917                 if (done_pbase_paths[mi] == hash)
 918                         return mi;
 919                 if (done_pbase_paths[mi] < hash)
 920                         hi = mi;
 921                 else
 922                         lo = mi + 1;
 923         }
 924         return -lo-1;
 925 }
 926
 927 static int check_pbase_path(unsigned hash)
 928 {
 929         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 930         if (0 <= pos)
 931                 return 1;
 932         pos = -pos - 1;
 933         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 934                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 935                 done_pbase_paths = xrealloc(done_pbase_paths,
 936                                             done_pbase_paths_alloc *
 937                                             sizeof(unsigned));
 938         }
 939         done_pbase_paths_num++;
 940         if (pos < done_pbase_paths_num)
 941                 memmove(done_pbase_paths + pos + 1,
 942                         done_pbase_paths + pos,
 943                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 944         done_pbase_paths[pos] = hash;
 945         return 0;
 946 }
 947
 948 static void add_preferred_base_object(const char *name)
 949 {
 950         struct pbase_tree *it;
 951         int cmplen;
 952         unsigned hash = name_hash(name);
 953
 954         if (!num_preferred_base || check_pbase_path(hash))
 955                 return;
 956
 957         cmplen = name_cmp_len(name);
 958         for (it = pbase_tree; it; it = it->next) {
 959                 if (cmplen == 0) {
 960                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 961                 }
 962                 else {
 963                         struct tree_desc tree;
 964                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 965                         add_pbase_object(&tree, name, cmplen, name);
 966                 }
 967         }
 968 }
 969
 970 static void add_preferred_base(unsigned char *sha1)
 971 {
 972         struct pbase_tree *it;
 973         void *data;
 974         unsigned long size;
 975         unsigned char tree_sha1[20];
 976
 977         if (window <= num_preferred_base++)
 978                 return;
 979
 980         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 981         if (!data)
 982                 return;
 983
 984         for (it = pbase_tree; it; it = it->next) {
 985                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 986                         free(data);
 987                         return;
 988                 }
 989         }
 990
 991         it = xcalloc(1, sizeof(*it));
 992         it->next = pbase_tree;
 993         pbase_tree = it;
 994
 995         hashcpy(it->pcache.sha1, tree_sha1);
 996         it->pcache.tree_data = data;
 997         it->pcache.tree_size = size;
 998 }
 999
1000 static void cleanup_preferred_base(void)
1001 {
1002         struct pbase_tree *it;
1003         unsigned i;
1004
1005         it = pbase_tree;
1006         pbase_tree = NULL;
1007         while (it) {
1008                 struct pbase_tree *this = it;
1009                 it = this->next;
1010                 free(this->pcache.tree_data);
1011                 free(this);
1012         }
1013
1014         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1015                 if (!pbase_tree_cache[i])
1016                         continue;
1017                 free(pbase_tree_cache[i]->tree_data);
1018                 free(pbase_tree_cache[i]);
1019                 pbase_tree_cache[i] = NULL;
1020         }
1021
1022         free(done_pbase_paths);
1023         done_pbase_paths = NULL;
1024         done_pbase_paths_num = done_pbase_paths_alloc = 0;
1025 }
1026
1027 static void check_object(struct object_entry *entry)
1028 {
1029         if (entry->in_pack) {
1030                 struct packed_git *p = entry->in_pack;
1031                 struct pack_window *w_curs = NULL;
1032                 const unsigned char *base_ref = NULL;
1033                 struct object_entry *base_entry;
1034                 unsigned long used, used_0;
1035                 unsigned int avail;
1036                 off_t ofs;
1037                 unsigned char *buf, c;
1038
1039                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1040
1041                 /*
1042                  * We want in_pack_type even if we do not reuse delta
1043                  * since non-delta representations could still be reused.
1044                  */
1045                 used = unpack_object_header_buffer(buf, avail,
1046                                                    &entry->in_pack_type,
1047                                                    &entry->size);
1048                 if (used == 0)
1049                         goto give_up;
1050
1051                 /*
1052                  * Determine if this is a delta and if so whether we can
1053                  * reuse it or not.  Otherwise let's find out as cheaply as
1054                  * possible what the actual type and size for this object is.
1055                  */
1056                 switch (entry->in_pack_type) {
1057                 default:
1058                         /* Not a delta hence we've already got all we need. */
1059                         entry->type = entry->in_pack_type;
1060                         entry->in_pack_header_size = used;
1061                         if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1062                                 goto give_up;
1063                         unuse_pack(&w_curs);
1064                         return;
1065                 case OBJ_REF_DELTA:
1066                         if (reuse_delta && !entry->preferred_base)
1067                                 base_ref = use_pack(p, &w_curs,
1068                                                 entry->in_pack_offset + used, NULL);
1069                         entry->in_pack_header_size = used + 20;
1070                         break;
1071                 case OBJ_OFS_DELTA:
1072                         buf = use_pack(p, &w_curs,
1073                                        entry->in_pack_offset + used, NULL);
1074                         used_0 = 0;
1075                         c = buf[used_0++];
1076                         ofs = c & 127;
1077                         while (c & 128) {
1078                                 ofs += 1;
1079                                 if (!ofs || MSB(ofs, 7)) {
1080                                         error("delta base offset overflow in pack for %s",
1081                                               sha1_to_hex(entry->idx.sha1));
1082                                         goto give_up;
1083                                 }
1084                                 c = buf[used_0++];
1085                                 ofs = (ofs << 7) + (c & 127);
1086                         }
1087                         ofs = entry->in_pack_offset - ofs;
1088                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1089                                 error("delta base offset out of bound for %s",
1090                                       sha1_to_hex(entry->idx.sha1));
1091                                 goto give_up;
1092                         }
1093                         if (reuse_delta && !entry->preferred_base) {
1094                                 struct revindex_entry *revidx;
1095                                 revidx = find_pack_revindex(p, ofs);
1096                                 if (!revidx)
1097                                         goto give_up;
1098                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1099                         }
1100                         entry->in_pack_header_size = used + used_0;
1101                         break;
1102                 }
1103
1104                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1105                         /*
1106                          * If base_ref was set above that means we wish to
1107                          * reuse delta data, and we even found that base
1108                          * in the list of objects we want to pack. Goodie!
1109                          *
1110                          * Depth value does not matter - find_deltas() will
1111                          * never consider reused delta as the base object to
1112                          * deltify other objects against, in order to avoid
1113                          * circular deltas.
1114                          */
1115                         entry->type = entry->in_pack_type;
1116                         entry->delta = base_entry;
1117                         entry->delta_size = entry->size;
1118                         entry->delta_sibling = base_entry->delta_child;
1119                         base_entry->delta_child = entry;
1120                         unuse_pack(&w_curs);
1121                         return;
1122                 }
1123
1124                 if (entry->type) {
1125                         /*
1126                          * This must be a delta and we already know what the
1127                          * final object type is.  Let's extract the actual
1128                          * object size from the delta header.
1129                          */
1130                         entry->size = get_size_from_delta(p, &w_curs,
1131                                         entry->in_pack_offset + entry->in_pack_header_size);
1132                         if (entry->size == 0)
1133                                 goto give_up;
1134                         unuse_pack(&w_curs);
1135                         return;
1136                 }
1137
1138                 /*
1139                  * No choice but to fall back to the recursive delta walk
1140                  * with sha1_object_info() to find about the object type
1141                  * at this point...
1142                  */
1143                 give_up:
1144                 unuse_pack(&w_curs);
1145         }
1146
1147         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1148         /*
1149          * The error condition is checked in prepare_pack().  This is
1150          * to permit a missing preferred base object to be ignored
1151          * as a preferred base.  Doing so can result in a larger
1152          * pack file, but the transfer will still take place.
1153          */
1154 }
1155
1156 static int pack_offset_sort(const void *_a, const void *_b)
1157 {
1158         const struct object_entry *a = *(struct object_entry **)_a;
1159         const struct object_entry *b = *(struct object_entry **)_b;
1160
1161         /* avoid filesystem trashing with loose objects */
1162         if (!a->in_pack && !b->in_pack)
1163                 return hashcmp(a->idx.sha1, b->idx.sha1);
1164
1165         if (a->in_pack < b->in_pack)
1166                 return -1;
1167         if (a->in_pack > b->in_pack)
1168                 return 1;
1169         return a->in_pack_offset < b->in_pack_offset ? -1 :
1170                         (a->in_pack_offset > b->in_pack_offset);
1171 }
1172
1173 static void get_object_details(void)
1174 {
1175         uint32_t i;
1176         struct object_entry **sorted_by_offset;
1177
1178         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1179         for (i = 0; i < nr_objects; i++)
1180                 sorted_by_offset[i] = objects + i;
1181         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1182
1183         for (i = 0; i < nr_objects; i++)
1184                 check_object(sorted_by_offset[i]);
1185
1186         free(sorted_by_offset);
1187 }
1188
1189 /*
1190  * We search for deltas in a list sorted by type, by filename hash, and then
1191  * by size, so that we see progressively smaller and smaller files.
1192  * That's because we prefer deltas to be from the bigger file
1193  * to the smaller -- deletes are potentially cheaper, but perhaps
1194  * more importantly, the bigger file is likely the more recent
1195  * one.  The deepest deltas are therefore the oldest objects which are
1196  * less susceptible to be accessed often.
1197  */
1198 static int type_size_sort(const void *_a, const void *_b)
1199 {
1200         const struct object_entry *a = *(struct object_entry **)_a;
1201         const struct object_entry *b = *(struct object_entry **)_b;
1202
1203         if (a->type > b->type)
1204                 return -1;
1205         if (a->type < b->type)
1206                 return 1;
1207         if (a->hash > b->hash)
1208                 return -1;
1209         if (a->hash < b->hash)
1210                 return 1;
1211         if (a->preferred_base > b->preferred_base)
1212                 return -1;
1213         if (a->preferred_base < b->preferred_base)
1214                 return 1;
1215         if (a->size > b->size)
1216                 return -1;
1217         if (a->size < b->size)
1218                 return 1;
1219         return a < b ? -1 : (a > b);  /* newest first */
1220 }
1221
1222 struct unpacked {
1223         struct object_entry *entry;
1224         void *data;
1225         struct delta_index *index;
1226         unsigned depth;
1227 };
1228
1229 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1230                            unsigned long delta_size)
1231 {
1232         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1233                 return 0;
1234
1235         if (delta_size < cache_max_small_delta_size)
1236                 return 1;
1237
1238         /* cache delta, if objects are large enough compared to delta size */
1239         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1240                 return 1;
1241
1242         return 0;
1243 }
1244
1245 #ifndef NO_PTHREADS
1246
1247 static pthread_mutex_t read_mutex;
1248 #define read_lock()             pthread_mutex_lock(&read_mutex)
1249 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1250
1251 static pthread_mutex_t cache_mutex;
1252 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1253 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1254
1255 static pthread_mutex_t progress_mutex;
1256 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1257 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1258
1259 #else
1260
1261 #define read_lock()             (void)0
1262 #define read_unlock()           (void)0
1263 #define cache_lock()            (void)0
1264 #define cache_unlock()          (void)0
1265 #define progress_lock()         (void)0
1266 #define progress_unlock()       (void)0
1267
1268 #endif
1269
1270 static int try_delta(struct unpacked *trg, struct unpacked *src,
1271                      unsigned max_depth, unsigned long *mem_usage)
1272 {
1273         struct object_entry *trg_entry = trg->entry;
1274         struct object_entry *src_entry = src->entry;
1275         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1276         unsigned ref_depth;
1277         enum object_type type;
1278         void *delta_buf;
1279
1280         /* Don't bother doing diffs between different types */
1281         if (trg_entry->type != src_entry->type)
1282                 return -1;
1283
1284         /*
1285          * We do not bother to try a delta that we discarded
1286          * on an earlier try, but only when reusing delta data.
1287          */
1288         if (reuse_delta && trg_entry->in_pack &&
1289             trg_entry->in_pack == src_entry->in_pack &&
1290             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1291             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1292                 return 0;
1293
1294         /* Let's not bust the allowed depth. */
1295         if (src->depth >= max_depth)
1296                 return 0;
1297
1298         /* Now some size filtering heuristics. */
1299         trg_size = trg_entry->size;
1300         if (!trg_entry->delta) {
1301                 max_size = trg_size/2 - 20;
1302                 ref_depth = 1;
1303         } else {
1304                 max_size = trg_entry->delta_size;
1305                 ref_depth = trg->depth;
1306         }
1307         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1308                                                 (max_depth - ref_depth + 1);
1309         if (max_size == 0)
1310                 return 0;
1311         src_size = src_entry->size;
1312         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1313         if (sizediff >= max_size)
1314                 return 0;
1315         if (trg_size < src_size / 32)
1316                 return 0;
1317
1318         /* Load data if not already done */
1319         if (!trg->data) {
1320                 read_lock();
1321                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1322                 read_unlock();
1323                 if (!trg->data)
1324                         die("object %s cannot be read",
1325                             sha1_to_hex(trg_entry->idx.sha1));
1326                 if (sz != trg_size)
1327                         die("object %s inconsistent object length (%lu vs %lu)",
1328                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1329                 *mem_usage += sz;
1330         }
1331         if (!src->data) {
1332                 read_lock();
1333                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1334                 read_unlock();
1335                 if (!src->data)
1336                         die("object %s cannot be read",
1337                             sha1_to_hex(src_entry->idx.sha1));
1338                 if (sz != src_size)
1339                         die("object %s inconsistent object length (%lu vs %lu)",
1340                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1341                 *mem_usage += sz;
1342         }
1343         if (!src->index) {
1344                 src->index = create_delta_index(src->data, src_size);
1345                 if (!src->index) {
1346                         static int warned = 0;
1347                         if (!warned++)
1348                                 warning("suboptimal pack - out of memory");
1349                         return 0;
1350                 }
1351                 *mem_usage += sizeof_delta_index(src->index);
1352         }
1353
1354         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1355         if (!delta_buf)
1356                 return 0;
1357
1358         if (trg_entry->delta) {
1359                 /* Prefer only shallower same-sized deltas. */
1360                 if (delta_size == trg_entry->delta_size &&
1361                     src->depth + 1 >= trg->depth) {
1362                         free(delta_buf);
1363                         return 0;
1364                 }
1365         }
1366
1367         /*
1368          * Handle memory allocation outside of the cache
1369          * accounting lock.  Compiler will optimize the strangeness
1370          * away when NO_PTHREADS is defined.
1371          */
1372         free(trg_entry->delta_data);
1373         cache_lock();
1374         if (trg_entry->delta_data) {
1375                 delta_cache_size -= trg_entry->delta_size;
1376                 trg_entry->delta_data = NULL;
1377         }
1378         if (delta_cacheable(src_size, trg_size, delta_size)) {
1379                 delta_cache_size += delta_size;
1380                 cache_unlock();
1381                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1382         } else {
1383                 cache_unlock();
1384                 free(delta_buf);
1385         }
1386
1387         trg_entry->delta = src_entry;
1388         trg_entry->delta_size = delta_size;
1389         trg->depth = src->depth + 1;
1390
1391         return 1;
1392 }
1393
1394 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1395 {
1396         struct object_entry *child = me->delta_child;
1397         unsigned int m = n;
1398         while (child) {
1399                 unsigned int c = check_delta_limit(child, n + 1);
1400                 if (m < c)
1401                         m = c;
1402                 child = child->delta_sibling;
1403         }
1404         return m;
1405 }
1406
1407 static unsigned long free_unpacked(struct unpacked *n)
1408 {
1409         unsigned long freed_mem = sizeof_delta_index(n->index);
1410         free_delta_index(n->index);
1411         n->index = NULL;
1412         if (n->data) {
1413                 freed_mem += n->entry->size;
1414                 free(n->data);
1415                 n->data = NULL;
1416         }
1417         n->entry = NULL;
1418         n->depth = 0;
1419         return freed_mem;
1420 }
1421
1422 static void find_deltas(struct object_entry **list, unsigned *list_size,
1423                         int window, int depth, unsigned *processed)
1424 {
1425         uint32_t i, idx = 0, count = 0;
1426         struct unpacked *array;
1427         unsigned long mem_usage = 0;
1428
1429         array = xcalloc(window, sizeof(struct unpacked));
1430
1431         for (;;) {
1432                 struct object_entry *entry;
1433                 struct unpacked *n = array + idx;
1434                 int j, max_depth, best_base = -1;
1435
1436                 progress_lock();
1437                 if (!*list_size) {
1438                         progress_unlock();
1439                         break;
1440                 }
1441                 entry = *list++;
1442                 (*list_size)--;
1443                 if (!entry->preferred_base) {
1444                         (*processed)++;
1445                         display_progress(progress_state, *processed);
1446                 }
1447                 progress_unlock();
1448
1449                 mem_usage -= free_unpacked(n);
1450                 n->entry = entry;
1451
1452                 while (window_memory_limit &&
1453                        mem_usage > window_memory_limit &&
1454                        count > 1) {
1455                         uint32_t tail = (idx + window - count) % window;
1456                         mem_usage -= free_unpacked(array + tail);
1457                         count--;
1458                 }
1459
1460                 /* We do not compute delta to *create* objects we are not
1461                  * going to pack.
1462                  */
1463                 if (entry->preferred_base)
1464                         goto next;
1465
1466                 /*
1467                  * If the current object is at pack edge, take the depth the
1468                  * objects that depend on the current object into account
1469                  * otherwise they would become too deep.
1470                  */
1471                 max_depth = depth;
1472                 if (entry->delta_child) {
1473                         max_depth -= check_delta_limit(entry, 0);
1474                         if (max_depth <= 0)
1475                                 goto next;
1476                 }
1477
1478                 j = window;
1479                 while (--j > 0) {
1480                         int ret;
1481                         uint32_t other_idx = idx + j;
1482                         struct unpacked *m;
1483                         if (other_idx >= window)
1484                                 other_idx -= window;
1485                         m = array + other_idx;
1486                         if (!m->entry)
1487                                 break;
1488                         ret = try_delta(n, m, max_depth, &mem_usage);
1489                         if (ret < 0)
1490                                 break;
1491                         else if (ret > 0)
1492                                 best_base = other_idx;
1493                 }
1494
1495                 /*
1496                  * If we decided to cache the delta data, then it is best
1497                  * to compress it right away.  First because we have to do
1498                  * it anyway, and doing it here while we're threaded will
1499                  * save a lot of time in the non threaded write phase,
1500                  * as well as allow for caching more deltas within
1501                  * the same cache size limit.
1502                  * ...
1503                  * But only if not writing to stdout, since in that case
1504                  * the network is most likely throttling writes anyway,
1505                  * and therefore it is best to go to the write phase ASAP
1506                  * instead, as we can afford spending more time compressing
1507                  * between writes at that moment.
1508                  */
1509                 if (entry->delta_data && !pack_to_stdout) {
1510                         entry->z_delta_size = do_compress(&entry->delta_data,
1511                                                           entry->delta_size);
1512                         cache_lock();
1513                         delta_cache_size -= entry->delta_size;
1514                         delta_cache_size += entry->z_delta_size;
1515                         cache_unlock();
1516                 }
1517
1518                 /* if we made n a delta, and if n is already at max
1519                  * depth, leaving it in the window is pointless.  we
1520                  * should evict it first.
1521                  */
1522                 if (entry->delta && max_depth <= n->depth)
1523                         continue;
1524
1525                 /*
1526                  * Move the best delta base up in the window, after the
1527                  * currently deltified object, to keep it longer.  It will
1528                  * be the first base object to be attempted next.
1529                  */
1530                 if (entry->delta) {
1531                         struct unpacked swap = array[best_base];
1532                         int dist = (window + idx - best_base) % window;
1533                         int dst = best_base;
1534                         while (dist--) {
1535                                 int src = (dst + 1) % window;
1536                                 array[dst] = array[src];
1537                                 dst = src;
1538                         }
1539                         array[dst] = swap;
1540                 }
1541
1542                 next:
1543                 idx++;
1544                 if (count + 1 < window)
1545                         count++;
1546                 if (idx >= window)
1547                         idx = 0;
1548         }
1549
1550         for (i = 0; i < window; ++i) {
1551                 free_delta_index(array[i].index);
1552                 free(array[i].data);
1553         }
1554         free(array);
1555 }
1556
1557 #ifndef NO_PTHREADS
1558
1559 /*
1560  * The main thread waits on the condition that (at least) one of the workers
1561  * has stopped working (which is indicated in the .working member of
1562  * struct thread_params).
1563  * When a work thread has completed its work, it sets .working to 0 and
1564  * signals the main thread and waits on the condition that .data_ready
1565  * becomes 1.
1566  */
1567
1568 struct thread_params {
1569         pthread_t thread;
1570         struct object_entry **list;
1571         unsigned list_size;
1572         unsigned remaining;
1573         int window;
1574         int depth;
1575         int working;
1576         int data_ready;
1577         pthread_mutex_t mutex;
1578         pthread_cond_t cond;
1579         unsigned *processed;
1580 };
1581
1582 static pthread_cond_t progress_cond;
1583
1584 /*
1585  * Mutex and conditional variable can't be statically-initialized on Windows.
1586  */
1587 static void init_threaded_search(void)
1588 {
1589         pthread_mutex_init(&read_mutex, NULL);
1590         pthread_mutex_init(&cache_mutex, NULL);
1591         pthread_mutex_init(&progress_mutex, NULL);
1592         pthread_cond_init(&progress_cond, NULL);
1593 }
1594
1595 static void cleanup_threaded_search(void)
1596 {
1597         pthread_cond_destroy(&progress_cond);
1598         pthread_mutex_destroy(&read_mutex);
1599         pthread_mutex_destroy(&cache_mutex);
1600         pthread_mutex_destroy(&progress_mutex);
1601 }
1602
1603 static void *threaded_find_deltas(void *arg)
1604 {
1605         struct thread_params *me = arg;
1606
1607         while (me->remaining) {
1608                 find_deltas(me->list, &me->remaining,
1609                             me->window, me->depth, me->processed);
1610
1611                 progress_lock();
1612                 me->working = 0;
1613                 pthread_cond_signal(&progress_cond);
1614                 progress_unlock();
1615
1616                 /*
1617                  * We must not set ->data_ready before we wait on the
1618                  * condition because the main thread may have set it to 1
1619                  * before we get here. In order to be sure that new
1620                  * work is available if we see 1 in ->data_ready, it
1621                  * was initialized to 0 before this thread was spawned
1622                  * and we reset it to 0 right away.
1623                  */
1624                 pthread_mutex_lock(&me->mutex);
1625                 while (!me->data_ready)
1626                         pthread_cond_wait(&me->cond, &me->mutex);
1627                 me->data_ready = 0;
1628                 pthread_mutex_unlock(&me->mutex);
1629         }
1630         /* leave ->working 1 so that this doesn't get more work assigned */
1631         return NULL;
1632 }
1633
1634 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1635                            int window, int depth, unsigned *processed)
1636 {
1637         struct thread_params *p;
1638         int i, ret, active_threads = 0;
1639
1640         init_threaded_search();
1641
1642         if (!delta_search_threads)      /* --threads=0 means autodetect */
1643                 delta_search_threads = online_cpus();
1644         if (delta_search_threads <= 1) {
1645                 find_deltas(list, &list_size, window, depth, processed);
1646                 cleanup_threaded_search();
1647                 return;
1648         }
1649         if (progress > pack_to_stdout)
1650                 fprintf(stderr, "Delta compression using up to %d threads.\n",
1651                                 delta_search_threads);
1652         p = xcalloc(delta_search_threads, sizeof(*p));
1653
1654         /* Partition the work amongst work threads. */
1655         for (i = 0; i < delta_search_threads; i++) {
1656                 unsigned sub_size = list_size / (delta_search_threads - i);
1657
1658                 /* don't use too small segments or no deltas will be found */
1659                 if (sub_size < 2*window && i+1 < delta_search_threads)
1660                         sub_size = 0;
1661
1662                 p[i].window = window;
1663                 p[i].depth = depth;
1664                 p[i].processed = processed;
1665                 p[i].working = 1;
1666                 p[i].data_ready = 0;
1667
1668                 /* try to split chunks on "path" boundaries */
1669                 while (sub_size && sub_size < list_size &&
1670                        list[sub_size]->hash &&
1671                        list[sub_size]->hash == list[sub_size-1]->hash)
1672                         sub_size++;
1673
1674                 p[i].list = list;
1675                 p[i].list_size = sub_size;
1676                 p[i].remaining = sub_size;
1677
1678                 list += sub_size;
1679                 list_size -= sub_size;
1680         }
1681
1682         /* Start work threads. */
1683         for (i = 0; i < delta_search_threads; i++) {
1684                 if (!p[i].list_size)
1685                         continue;
1686                 pthread_mutex_init(&p[i].mutex, NULL);
1687                 pthread_cond_init(&p[i].cond, NULL);
1688                 ret = pthread_create(&p[i].thread, NULL,
1689                                      threaded_find_deltas, &p[i]);
1690                 if (ret)
1691                         die("unable to create thread: %s", strerror(ret));
1692                 active_threads++;
1693         }
1694
1695         /*
1696          * Now let's wait for work completion.  Each time a thread is done
1697          * with its work, we steal half of the remaining work from the
1698          * thread with the largest number of unprocessed objects and give
1699          * it to that newly idle thread.  This ensure good load balancing
1700          * until the remaining object list segments are simply too short
1701          * to be worth splitting anymore.
1702          */
1703         while (active_threads) {
1704                 struct thread_params *target = NULL;
1705                 struct thread_params *victim = NULL;
1706                 unsigned sub_size = 0;
1707
1708                 progress_lock();
1709                 for (;;) {
1710                         for (i = 0; !target && i < delta_search_threads; i++)
1711                                 if (!p[i].working)
1712                                         target = &p[i];
1713                         if (target)
1714                                 break;
1715                         pthread_cond_wait(&progress_cond, &progress_mutex);
1716                 }
1717
1718                 for (i = 0; i < delta_search_threads; i++)
1719                         if (p[i].remaining > 2*window &&
1720                             (!victim || victim->remaining < p[i].remaining))
1721                                 victim = &p[i];
1722                 if (victim) {
1723                         sub_size = victim->remaining / 2;
1724                         list = victim->list + victim->list_size - sub_size;
1725                         while (sub_size && list[0]->hash &&
1726                                list[0]->hash == list[-1]->hash) {
1727                                 list++;
1728                                 sub_size--;
1729                         }
1730                         if (!sub_size) {
1731                                 /*
1732                                  * It is possible for some "paths" to have
1733                                  * so many objects that no hash boundary
1734                                  * might be found.  Let's just steal the
1735                                  * exact half in that case.
1736                                  */
1737                                 sub_size = victim->remaining / 2;
1738                                 list -= sub_size;
1739                         }
1740                         target->list = list;
1741                         victim->list_size -= sub_size;
1742                         victim->remaining -= sub_size;
1743                 }
1744                 target->list_size = sub_size;
1745                 target->remaining = sub_size;
1746                 target->working = 1;
1747                 progress_unlock();
1748
1749                 pthread_mutex_lock(&target->mutex);
1750                 target->data_ready = 1;
1751                 pthread_cond_signal(&target->cond);
1752                 pthread_mutex_unlock(&target->mutex);
1753
1754                 if (!sub_size) {
1755                         pthread_join(target->thread, NULL);
1756                         pthread_cond_destroy(&target->cond);
1757                         pthread_mutex_destroy(&target->mutex);
1758                         active_threads--;
1759                 }
1760         }
1761         cleanup_threaded_search();
1762         free(p);
1763 }
1764
1765 #else
1766 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1767 #endif
1768
1769 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1770 {
1771         unsigned char peeled[20];
1772
1773         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1774             !peel_ref(path, peeled)        && /* peelable? */
1775             !is_null_sha1(peeled)          && /* annotated tag? */
1776             locate_object_entry(peeled))      /* object packed? */
1777                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1778         return 0;
1779 }
1780
1781 static void prepare_pack(int window, int depth)
1782 {
1783         struct object_entry **delta_list;
1784         uint32_t i, nr_deltas;
1785         unsigned n;
1786
1787         get_object_details();
1788
1789         /*
1790          * If we're locally repacking then we need to be doubly careful
1791          * from now on in order to make sure no stealth corruption gets
1792          * propagated to the new pack.  Clients receiving streamed packs
1793          * should validate everything they get anyway so no need to incur
1794          * the additional cost here in that case.
1795          */
1796         if (!pack_to_stdout)
1797                 do_check_packed_object_crc = 1;
1798
1799         if (!nr_objects || !window || !depth)
1800                 return;
1801
1802         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1803         nr_deltas = n = 0;
1804
1805         for (i = 0; i < nr_objects; i++) {
1806                 struct object_entry *entry = objects + i;
1807
1808                 if (entry->delta)
1809                         /* This happens if we decided to reuse existing
1810                          * delta from a pack.  "reuse_delta &&" is implied.
1811                          */
1812                         continue;
1813
1814                 if (entry->size < 50)
1815                         continue;
1816
1817                 if (entry->no_try_delta)
1818                         continue;
1819
1820                 if (!entry->preferred_base) {
1821                         nr_deltas++;
1822                         if (entry->type < 0)
1823                                 die("unable to get type of object %s",
1824                                     sha1_to_hex(entry->idx.sha1));
1825                 } else {
1826                         if (entry->type < 0) {
1827                                 /*
1828                                  * This object is not found, but we
1829                                  * don't have to include it anyway.
1830                                  */
1831                                 continue;
1832                         }
1833                 }
1834
1835                 delta_list[n++] = entry;
1836         }
1837
1838         if (nr_deltas && n > 1) {
1839                 unsigned nr_done = 0;
1840                 if (progress)
1841                         progress_state = start_progress("Compressing objects",
1842                                                         nr_deltas);
1843                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1844                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1845                 stop_progress(&progress_state);
1846                 if (nr_done != nr_deltas)
1847                         die("inconsistency with delta count");
1848         }
1849         free(delta_list);
1850 }
1851
1852 static int git_pack_config(const char *k, const char *v, void *cb)
1853 {
1854         if (!strcmp(k, "pack.window")) {
1855                 window = git_config_int(k, v);
1856                 return 0;
1857         }
1858         if (!strcmp(k, "pack.windowmemory")) {
1859                 window_memory_limit = git_config_ulong(k, v);
1860                 return 0;
1861         }
1862         if (!strcmp(k, "pack.depth")) {
1863                 depth = git_config_int(k, v);
1864                 return 0;
1865         }
1866         if (!strcmp(k, "pack.compression")) {
1867                 int level = git_config_int(k, v);
1868                 if (level == -1)
1869                         level = Z_DEFAULT_COMPRESSION;
1870                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1871                         die("bad pack compression level %d", level);
1872                 pack_compression_level = level;
1873                 pack_compression_seen = 1;
1874                 return 0;
1875         }
1876         if (!strcmp(k, "pack.deltacachesize")) {
1877                 max_delta_cache_size = git_config_int(k, v);
1878                 return 0;
1879         }
1880         if (!strcmp(k, "pack.deltacachelimit")) {
1881                 cache_max_small_delta_size = git_config_int(k, v);
1882                 return 0;
1883         }
1884         if (!strcmp(k, "pack.threads")) {
1885                 delta_search_threads = git_config_int(k, v);
1886                 if (delta_search_threads < 0)
1887                         die("invalid number of threads specified (%d)",
1888                             delta_search_threads);
1889 #ifdef NO_PTHREADS
1890                 if (delta_search_threads != 1)
1891                         warning("no threads support, ignoring %s", k);
1892 #endif
1893                 return 0;
1894         }
1895         if (!strcmp(k, "pack.indexversion")) {
1896                 pack_idx_default_version = git_config_int(k, v);
1897                 if (pack_idx_default_version > 2)
1898                         die("bad pack.indexversion=%"PRIu32,
1899                                 pack_idx_default_version);
1900                 return 0;
1901         }
1902         if (!strcmp(k, "pack.packsizelimit")) {
1903                 pack_size_limit_cfg = git_config_ulong(k, v);
1904                 return 0;
1905         }
1906         return git_default_config(k, v, cb);
1907 }
1908
1909 static void read_object_list_from_stdin(void)
1910 {
1911         char line[40 + 1 + PATH_MAX + 2];
1912         unsigned char sha1[20];
1913
1914         for (;;) {
1915                 if (!fgets(line, sizeof(line), stdin)) {
1916                         if (feof(stdin))
1917                                 break;
1918                         if (!ferror(stdin))
1919                                 die("fgets returned NULL, not EOF, not error!");
1920                         if (errno != EINTR)
1921                                 die_errno("fgets");
1922                         clearerr(stdin);
1923                         continue;
1924                 }
1925                 if (line[0] == '-') {
1926                         if (get_sha1_hex(line+1, sha1))
1927                                 die("expected edge sha1, got garbage:\n %s",
1928                                     line);
1929                         add_preferred_base(sha1);
1930                         continue;
1931                 }
1932                 if (get_sha1_hex(line, sha1))
1933                         die("expected sha1, got garbage:\n %s", line);
1934
1935                 add_preferred_base_object(line+41);
1936                 add_object_entry(sha1, 0, line+41, 0);
1937         }
1938 }
1939
1940 #define OBJECT_ADDED (1u<<20)
1941
1942 static void show_commit(struct commit *commit, void *data)
1943 {
1944         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1945         commit->object.flags |= OBJECT_ADDED;
1946 }
1947
1948 static void show_object(struct object *obj, const struct name_path *path, const char *last)
1949 {
1950         char *name = path_name(path, last);
1951
1952         add_preferred_base_object(name);
1953         add_object_entry(obj->sha1, obj->type, name, 0);
1954         obj->flags |= OBJECT_ADDED;
1955
1956         /*
1957          * We will have generated the hash from the name,
1958          * but not saved a pointer to it - we can free it
1959          */
1960         free((char *)name);
1961 }
1962
1963 static void show_edge(struct commit *commit)
1964 {
1965         add_preferred_base(commit->object.sha1);
1966 }
1967
1968 struct in_pack_object {
1969         off_t offset;
1970         struct object *object;
1971 };
1972
1973 struct in_pack {
1974         int alloc;
1975         int nr;
1976         struct in_pack_object *array;
1977 };
1978
1979 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1980 {
1981         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1982         in_pack->array[in_pack->nr].object = object;
1983         in_pack->nr++;
1984 }
1985
1986 /*
1987  * Compare the objects in the offset order, in order to emulate the
1988  * "git rev-list --objects" output that produced the pack originally.
1989  */
1990 static int ofscmp(const void *a_, const void *b_)
1991 {
1992         struct in_pack_object *a = (struct in_pack_object *)a_;
1993         struct in_pack_object *b = (struct in_pack_object *)b_;
1994
1995         if (a->offset < b->offset)
1996                 return -1;
1997         else if (a->offset > b->offset)
1998                 return 1;
1999         else
2000                 return hashcmp(a->object->sha1, b->object->sha1);
2001 }
2002
2003 static void add_objects_in_unpacked_packs(struct rev_info *revs)
2004 {
2005         struct packed_git *p;
2006         struct in_pack in_pack;
2007         uint32_t i;
2008
2009         memset(&in_pack, 0, sizeof(in_pack));
2010
2011         for (p = packed_git; p; p = p->next) {
2012                 const unsigned char *sha1;
2013                 struct object *o;
2014
2015                 if (!p->pack_local || p->pack_keep)
2016                         continue;
2017                 if (open_pack_index(p))
2018                         die("cannot open pack index");
2019
2020                 ALLOC_GROW(in_pack.array,
2021                            in_pack.nr + p->num_objects,
2022                            in_pack.alloc);
2023
2024                 for (i = 0; i < p->num_objects; i++) {
2025                         sha1 = nth_packed_object_sha1(p, i);
2026                         o = lookup_unknown_object(sha1);
2027                         if (!(o->flags & OBJECT_ADDED))
2028                                 mark_in_pack_object(o, p, &in_pack);
2029                         o->flags |= OBJECT_ADDED;
2030                 }
2031         }
2032
2033         if (in_pack.nr) {
2034                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
2035                       ofscmp);
2036                 for (i = 0; i < in_pack.nr; i++) {
2037                         struct object *o = in_pack.array[i].object;
2038                         add_object_entry(o->sha1, o->type, "", 0);
2039                 }
2040         }
2041         free(in_pack.array);
2042 }
2043
2044 static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2045 {
2046         static struct packed_git *last_found = (void *)1;
2047         struct packed_git *p;
2048
2049         p = (last_found != (void *)1) ? last_found : packed_git;
2050
2051         while (p) {
2052                 if ((!p->pack_local || p->pack_keep) &&
2053                         find_pack_entry_one(sha1, p)) {
2054                         last_found = p;
2055                         return 1;
2056                 }
2057                 if (p == last_found)
2058                         p = packed_git;
2059                 else
2060                         p = p->next;
2061                 if (p == last_found)
2062                         p = p->next;
2063         }
2064         return 0;
2065 }
2066
2067 static void loosen_unused_packed_objects(struct rev_info *revs)
2068 {
2069         struct packed_git *p;
2070         uint32_t i;
2071         const unsigned char *sha1;
2072
2073         for (p = packed_git; p; p = p->next) {
2074                 if (!p->pack_local || p->pack_keep)
2075                         continue;
2076
2077                 if (open_pack_index(p))
2078                         die("cannot open pack index");
2079
2080                 for (i = 0; i < p->num_objects; i++) {
2081                         sha1 = nth_packed_object_sha1(p, i);
2082                         if (!locate_object_entry(sha1) &&
2083                                 !has_sha1_pack_kept_or_nonlocal(sha1))
2084                                 if (force_object_loose(sha1, p->mtime))
2085                                         die("unable to force loose object");
2086                 }
2087         }
2088 }
2089
2090 static void get_object_list(int ac, const char **av)
2091 {
2092         struct rev_info revs;
2093         char line[1000];
2094         int flags = 0;
2095
2096         init_revisions(&revs, NULL);
2097         save_commit_buffer = 0;
2098         setup_revisions(ac, av, &revs, NULL);
2099
2100         while (fgets(line, sizeof(line), stdin) != NULL) {
2101                 int len = strlen(line);
2102                 if (len && line[len - 1] == '\n')
2103                         line[--len] = 0;
2104                 if (!len)
2105                         break;
2106                 if (*line == '-') {
2107                         if (!strcmp(line, "--not")) {
2108                                 flags ^= UNINTERESTING;
2109                                 continue;
2110                         }
2111                         die("not a rev '%s'", line);
2112                 }
2113                 if (handle_revision_arg(line, &revs, flags, 1))
2114                         die("bad revision '%s'", line);
2115         }
2116
2117         if (prepare_revision_walk(&revs))
2118                 die("revision walk setup failed");
2119         mark_edges_uninteresting(revs.commits, &revs, show_edge);
2120         traverse_commit_list(&revs, show_commit, show_object, NULL);
2121
2122         if (keep_unreachable)
2123                 add_objects_in_unpacked_packs(&revs);
2124         if (unpack_unreachable)
2125                 loosen_unused_packed_objects(&revs);
2126 }
2127
2128 static int adjust_perm(const char *path, mode_t mode)
2129 {
2130         if (chmod(path, mode))
2131                 return -1;
2132         return adjust_shared_perm(path);
2133 }
2134
2135 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2136 {
2137         int use_internal_rev_list = 0;
2138         int thin = 0;
2139         int all_progress_implied = 0;
2140         uint32_t i;
2141         const char **rp_av;
2142         int rp_ac_alloc = 64;
2143         int rp_ac;
2144
2145         read_replace_refs = 0;
2146
2147         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2148
2149         rp_av[0] = "pack-objects";
2150         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2151         rp_ac = 2;
2152
2153         git_config(git_pack_config, NULL);
2154         if (!pack_compression_seen && core_compression_seen)
2155                 pack_compression_level = core_compression_level;
2156
2157         progress = isatty(2);
2158         for (i = 1; i < argc; i++) {
2159                 const char *arg = argv[i];
2160
2161                 if (*arg != '-')
2162                         break;
2163
2164                 if (!strcmp("--non-empty", arg)) {
2165                         non_empty = 1;
2166                         continue;
2167                 }
2168                 if (!strcmp("--local", arg)) {
2169                         local = 1;
2170                         continue;
2171                 }
2172                 if (!strcmp("--incremental", arg)) {
2173                         incremental = 1;
2174                         continue;
2175                 }
2176                 if (!strcmp("--honor-pack-keep", arg)) {
2177                         ignore_packed_keep = 1;
2178                         continue;
2179                 }
2180                 if (!prefixcmp(arg, "--compression=")) {
2181                         char *end;
2182                         int level = strtoul(arg+14, &end, 0);
2183                         if (!arg[14] || *end)
2184                                 usage(pack_usage);
2185                         if (level == -1)
2186                                 level = Z_DEFAULT_COMPRESSION;
2187                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2188                                 die("bad pack compression level %d", level);
2189                         pack_compression_level = level;
2190                         continue;
2191                 }
2192                 if (!prefixcmp(arg, "--max-pack-size=")) {
2193                         pack_size_limit_cfg = 0;
2194                         if (!git_parse_ulong(arg+16, &pack_size_limit))
2195                                 usage(pack_usage);
2196                         continue;
2197                 }
2198                 if (!prefixcmp(arg, "--window=")) {
2199                         char *end;
2200                         window = strtoul(arg+9, &end, 0);
2201                         if (!arg[9] || *end)
2202                                 usage(pack_usage);
2203                         continue;
2204                 }
2205                 if (!prefixcmp(arg, "--window-memory=")) {
2206                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2207                                 usage(pack_usage);
2208                         continue;
2209                 }
2210                 if (!prefixcmp(arg, "--threads=")) {
2211                         char *end;
2212                         delta_search_threads = strtoul(arg+10, &end, 0);
2213                         if (!arg[10] || *end || delta_search_threads < 0)
2214                                 usage(pack_usage);
2215 #ifdef NO_PTHREADS
2216                         if (delta_search_threads != 1)
2217                                 warning("no threads support, "
2218                                         "ignoring %s", arg);
2219 #endif
2220                         continue;
2221                 }
2222                 if (!prefixcmp(arg, "--depth=")) {
2223                         char *end;
2224                         depth = strtoul(arg+8, &end, 0);
2225                         if (!arg[8] || *end)
2226                                 usage(pack_usage);
2227                         continue;
2228                 }
2229                 if (!strcmp("--progress", arg)) {
2230                         progress = 1;
2231                         continue;
2232                 }
2233                 if (!strcmp("--all-progress", arg)) {
2234                         progress = 2;
2235                         continue;
2236                 }
2237                 if (!strcmp("--all-progress-implied", arg)) {
2238                         all_progress_implied = 1;
2239                         continue;
2240                 }
2241                 if (!strcmp("-q", arg)) {
2242                         progress = 0;
2243                         continue;
2244                 }
2245                 if (!strcmp("--no-reuse-delta", arg)) {
2246                         reuse_delta = 0;
2247                         continue;
2248                 }
2249                 if (!strcmp("--no-reuse-object", arg)) {
2250                         reuse_object = reuse_delta = 0;
2251                         continue;
2252                 }
2253                 if (!strcmp("--delta-base-offset", arg)) {
2254                         allow_ofs_delta = 1;
2255                         continue;
2256                 }
2257                 if (!strcmp("--stdout", arg)) {
2258                         pack_to_stdout = 1;
2259                         continue;
2260                 }
2261                 if (!strcmp("--revs", arg)) {
2262                         use_internal_rev_list = 1;
2263                         continue;
2264                 }
2265                 if (!strcmp("--keep-unreachable", arg)) {
2266                         keep_unreachable = 1;
2267                         continue;
2268                 }
2269                 if (!strcmp("--unpack-unreachable", arg)) {
2270                         unpack_unreachable = 1;
2271                         continue;
2272                 }
2273                 if (!strcmp("--include-tag", arg)) {
2274                         include_tag = 1;
2275                         continue;
2276                 }
2277                 if (!strcmp("--unpacked", arg) ||
2278                     !strcmp("--reflog", arg) ||
2279                     !strcmp("--all", arg)) {
2280                         use_internal_rev_list = 1;
2281                         if (rp_ac >= rp_ac_alloc - 1) {
2282                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2283                                 rp_av = xrealloc(rp_av,
2284                                                  rp_ac_alloc * sizeof(*rp_av));
2285                         }
2286                         rp_av[rp_ac++] = arg;
2287                         continue;
2288                 }
2289                 if (!strcmp("--thin", arg)) {
2290                         use_internal_rev_list = 1;
2291                         thin = 1;
2292                         rp_av[1] = "--objects-edge";
2293                         continue;
2294                 }
2295                 if (!prefixcmp(arg, "--index-version=")) {
2296                         char *c;
2297                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2298                         if (pack_idx_default_version > 2)
2299                                 die("bad %s", arg);
2300                         if (*c == ',')
2301                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2302                         if (*c || pack_idx_off32_limit & 0x80000000)
2303                                 die("bad %s", arg);
2304                         continue;
2305                 }
2306                 if (!strcmp(arg, "--keep-true-parents")) {
2307                         grafts_replace_parents = 0;
2308                         continue;
2309                 }
2310                 usage(pack_usage);
2311         }
2312
2313         /* Traditionally "pack-objects [options] base extra" failed;
2314          * we would however want to take refs parameter that would
2315          * have been given to upstream rev-list ourselves, which means
2316          * we somehow want to say what the base name is.  So the
2317          * syntax would be:
2318          *
2319          * pack-objects [options] base <refs...>
2320          *
2321          * in other words, we would treat the first non-option as the
2322          * base_name and send everything else to the internal revision
2323          * walker.
2324          */
2325
2326         if (!pack_to_stdout)
2327                 base_name = argv[i++];
2328
2329         if (pack_to_stdout != !base_name)
2330                 usage(pack_usage);
2331
2332         if (!pack_to_stdout && !pack_size_limit)
2333                 pack_size_limit = pack_size_limit_cfg;
2334         if (pack_to_stdout && pack_size_limit)
2335                 die("--max-pack-size cannot be used to build a pack for transfer.");
2336         if (pack_size_limit && pack_size_limit < 1024*1024) {
2337                 warning("minimum pack size limit is 1 MiB");
2338                 pack_size_limit = 1024*1024;
2339         }
2340
2341         if (!pack_to_stdout && thin)
2342                 die("--thin cannot be used to build an indexable pack.");
2343
2344         if (keep_unreachable && unpack_unreachable)
2345                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2346
2347         if (progress && all_progress_implied)
2348                 progress = 2;
2349
2350         prepare_packed_git();
2351
2352         if (progress)
2353                 progress_state = start_progress("Counting objects", 0);
2354         if (!use_internal_rev_list)
2355                 read_object_list_from_stdin();
2356         else {
2357                 rp_av[rp_ac] = NULL;
2358                 get_object_list(rp_ac, rp_av);
2359         }
2360         cleanup_preferred_base();
2361         if (include_tag && nr_result)
2362                 for_each_ref(add_ref_tag, NULL);
2363         stop_progress(&progress_state);
2364
2365         if (non_empty && !nr_result)
2366                 return 0;
2367         if (nr_result)
2368                 prepare_pack(window, depth);
2369         write_pack_file();
2370         if (progress)
2371                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2372                         " reused %"PRIu32" (delta %"PRIu32")\n",
2373                         written, written_delta, reused, reused_delta);
2374         return 0;
2375 }