builtin-pack-objects.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "attr.h"
   4 #include "object.h"
   5 #include "blob.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "tree.h"
   9 #include "delta.h"
  10 #include "pack.h"
  11 #include "pack-revindex.h"
  12 #include "csum-file.h"
  13 #include "tree-walk.h"
  14 #include "diff.h"
  15 #include "revision.h"
  16 #include "list-objects.h"
  17 #include "progress.h"
  18 #include "refs.h"
  19
  20 #ifdef THREADED_DELTA_SEARCH
  21 #include "thread-utils.h"
  22 #include <pthread.h>
  23 #endif
  24
  25 static const char pack_usage[] = "\
  26 git-pack-objects [{ -q | --progress | --all-progress }] \n\
  27         [--max-pack-size=N] [--local] [--incremental] \n\
  28         [--window=N] [--window-memory=N] [--depth=N] \n\
  29         [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
  30         [--threads=N] [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
  31         [--stdout | base-name] [--include-tag] \n\
  32         [--keep-unreachable | --unpack-unreachable] \n\
  33         [<ref-list | <object-list]";
  34
  35 struct object_entry {
  36         struct pack_idx_entry idx;
  37         unsigned long size;     /* uncompressed size */
  38         struct packed_git *in_pack;     /* already in pack */
  39         off_t in_pack_offset;
  40         struct object_entry *delta;     /* delta base object */
  41         struct object_entry *delta_child; /* deltified objects who bases me */
  42         struct object_entry *delta_sibling; /* other deltified objects who
  43                                              * uses the same base as me
  44                                              */
  45         void *delta_data;       /* cached delta (uncompressed) */
  46         unsigned long delta_size;       /* delta data size (uncompressed) */
  47         unsigned long z_delta_size;     /* delta data size (compressed) */
  48         unsigned int hash;      /* name hint hash */
  49         enum object_type type;
  50         enum object_type in_pack_type;  /* could be delta */
  51         unsigned char in_pack_header_size;
  52         unsigned char preferred_base; /* we do not pack this, but is available
  53                                        * to be used as the base object to delta
  54                                        * objects against.
  55                                        */
  56         unsigned char no_try_delta;
  57 };
  58
  59 /*
  60  * Objects we are going to pack are collected in objects array (dynamically
  61  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  62  * in the order we see -- typically rev-list --objects order that gives us
  63  * nice "minimum seek" order.
  64  */
  65 static struct object_entry *objects;
  66 static struct pack_idx_entry **written_list;
  67 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
  68
  69 static int non_empty;
  70 static int reuse_delta = 1, reuse_object = 1;
  71 static int keep_unreachable, unpack_unreachable, include_tag;
  72 static int local;
  73 static int incremental;
  74 static int allow_ofs_delta;
  75 static const char *base_name;
  76 static int progress = 1;
  77 static int window = 10;
  78 static uint32_t pack_size_limit, pack_size_limit_cfg;
  79 static int depth = 50;
  80 static int delta_search_threads = 1;
  81 static int pack_to_stdout;
  82 static int num_preferred_base;
  83 static struct progress *progress_state;
  84 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  85 static int pack_compression_seen;
  86
  87 static unsigned long delta_cache_size = 0;
  88 static unsigned long max_delta_cache_size = 0;
  89 static unsigned long cache_max_small_delta_size = 1000;
  90
  91 static unsigned long window_memory_limit = 0;
  92
  93 /*
  94  * The object names in objects array are hashed with this hashtable,
  95  * to help looking up the entry by object name.
  96  * This hashtable is built after all the objects are seen.
  97  */
  98 static int *object_ix;
  99 static int object_ix_hashsz;
 100
 101 /*
 102  * stats
 103  */
 104 static uint32_t written, written_delta;
 105 static uint32_t reused, reused_delta;
 106
 107
 108 static void *get_delta(struct object_entry *entry)
 109 {
 110         unsigned long size, base_size, delta_size;
 111         void *buf, *base_buf, *delta_buf;
 112         enum object_type type;
 113
 114         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 115         if (!buf)
 116                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 117         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
 118         if (!base_buf)
 119                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 120         delta_buf = diff_delta(base_buf, base_size,
 121                                buf, size, &delta_size, 0);
 122         if (!delta_buf || delta_size != entry->delta_size)
 123                 die("delta size changed");
 124         free(buf);
 125         free(base_buf);
 126         return delta_buf;
 127 }
 128
 129 static unsigned long do_compress(void **pptr, unsigned long size)
 130 {
 131         z_stream stream;
 132         void *in, *out;
 133         unsigned long maxsize;
 134
 135         memset(&stream, 0, sizeof(stream));
 136         deflateInit(&stream, pack_compression_level);
 137         maxsize = deflateBound(&stream, size);
 138
 139         in = *pptr;
 140         out = xmalloc(maxsize);
 141         *pptr = out;
 142
 143         stream.next_in = in;
 144         stream.avail_in = size;
 145         stream.next_out = out;
 146         stream.avail_out = maxsize;
 147         while (deflate(&stream, Z_FINISH) == Z_OK)
 148                 ; /* nothing */
 149         deflateEnd(&stream);
 150
 151         free(in);
 152         return stream.total_out;
 153 }
 154
 155 /*
 156  * The per-object header is a pretty dense thing, which is
 157  *  - first byte: low four bits are "size", then three bits of "type",
 158  *    and the high bit is "size continues".
 159  *  - each byte afterwards: low seven bits are size continuation,
 160  *    with the high bit being "size continues"
 161  */
 162 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 163 {
 164         int n = 1;
 165         unsigned char c;
 166
 167         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 168                 die("bad type %d", type);
 169
 170         c = (type << 4) | (size & 15);
 171         size >>= 4;
 172         while (size) {
 173                 *hdr++ = c | 0x80;
 174                 c = size & 0x7f;
 175                 size >>= 7;
 176                 n++;
 177         }
 178         *hdr = c;
 179         return n;
 180 }
 181
 182 /*
 183  * we are going to reuse the existing object data as is.  make
 184  * sure it is not corrupt.
 185  */
 186 static int check_pack_inflate(struct packed_git *p,
 187                 struct pack_window **w_curs,
 188                 off_t offset,
 189                 off_t len,
 190                 unsigned long expect)
 191 {
 192         z_stream stream;
 193         unsigned char fakebuf[4096], *in;
 194         int st;
 195
 196         memset(&stream, 0, sizeof(stream));
 197         inflateInit(&stream);
 198         do {
 199                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 200                 stream.next_in = in;
 201                 stream.next_out = fakebuf;
 202                 stream.avail_out = sizeof(fakebuf);
 203                 st = inflate(&stream, Z_FINISH);
 204                 offset += stream.next_in - in;
 205         } while (st == Z_OK || st == Z_BUF_ERROR);
 206         inflateEnd(&stream);
 207         return (st == Z_STREAM_END &&
 208                 stream.total_out == expect &&
 209                 stream.total_in == len) ? 0 : -1;
 210 }
 211
 212 static int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
 213                           off_t offset, off_t len, unsigned int nr)
 214 {
 215         const uint32_t *index_crc;
 216         uint32_t data_crc = crc32(0, Z_NULL, 0);
 217
 218         do {
 219                 unsigned int avail;
 220                 void *data = use_pack(p, w_curs, offset, &avail);
 221                 if (avail > len)
 222                         avail = len;
 223                 data_crc = crc32(data_crc, data, avail);
 224                 offset += avail;
 225                 len -= avail;
 226         } while (len);
 227
 228         index_crc = p->index_data;
 229         index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
 230
 231         return data_crc != ntohl(*index_crc);
 232 }
 233
 234 static void copy_pack_data(struct sha1file *f,
 235                 struct packed_git *p,
 236                 struct pack_window **w_curs,
 237                 off_t offset,
 238                 off_t len)
 239 {
 240         unsigned char *in;
 241         unsigned int avail;
 242
 243         while (len) {
 244                 in = use_pack(p, w_curs, offset, &avail);
 245                 if (avail > len)
 246                         avail = (unsigned int)len;
 247                 sha1write(f, in, avail);
 248                 offset += avail;
 249                 len -= avail;
 250         }
 251 }
 252
 253 static unsigned long write_object(struct sha1file *f,
 254                                   struct object_entry *entry,
 255                                   off_t write_offset)
 256 {
 257         unsigned long size, limit, datalen;
 258         void *buf;
 259         unsigned char header[10], dheader[10];
 260         unsigned hdrlen;
 261         enum object_type type;
 262         int usable_delta, to_reuse;
 263
 264         if (!pack_to_stdout)
 265                 crc32_begin(f);
 266
 267         type = entry->type;
 268
 269         /* write limit if limited packsize and not first object */
 270         limit = pack_size_limit && nr_written ?
 271                         pack_size_limit - write_offset : 0;
 272
 273         if (!entry->delta)
 274                 usable_delta = 0;       /* no delta */
 275         else if (!pack_size_limit)
 276                usable_delta = 1;        /* unlimited packfile */
 277         else if (entry->delta->idx.offset == (off_t)-1)
 278                 usable_delta = 0;       /* base was written to another pack */
 279         else if (entry->delta->idx.offset)
 280                 usable_delta = 1;       /* base already exists in this pack */
 281         else
 282                 usable_delta = 0;       /* base could end up in another pack */
 283
 284         if (!reuse_object)
 285                 to_reuse = 0;   /* explicit */
 286         else if (!entry->in_pack)
 287                 to_reuse = 0;   /* can't reuse what we don't have */
 288         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
 289                                 /* check_object() decided it for us ... */
 290                 to_reuse = usable_delta;
 291                                 /* ... but pack split may override that */
 292         else if (type != entry->in_pack_type)
 293                 to_reuse = 0;   /* pack has delta which is unusable */
 294         else if (entry->delta)
 295                 to_reuse = 0;   /* we want to pack afresh */
 296         else
 297                 to_reuse = 1;   /* we have it in-pack undeltified,
 298                                  * and we do not need to deltify it.
 299                                  */
 300
 301         if (!to_reuse) {
 302                 if (!usable_delta) {
 303                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 304                         if (!buf)
 305                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 306                         /*
 307                          * make sure no cached delta data remains from a
 308                          * previous attempt before a pack split occured.
 309                          */
 310                         free(entry->delta_data);
 311                         entry->delta_data = NULL;
 312                         entry->z_delta_size = 0;
 313                 } else if (entry->delta_data) {
 314                         size = entry->delta_size;
 315                         buf = entry->delta_data;
 316                         entry->delta_data = NULL;
 317                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 318                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 319                 } else {
 320                         buf = get_delta(entry);
 321                         size = entry->delta_size;
 322                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 323                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 324                 }
 325
 326                 if (entry->z_delta_size)
 327                         datalen = entry->z_delta_size;
 328                 else
 329                         datalen = do_compress(&buf, size);
 330
 331                 /*
 332                  * The object header is a byte of 'type' followed by zero or
 333                  * more bytes of length.
 334                  */
 335                 hdrlen = encode_header(type, size, header);
 336
 337                 if (type == OBJ_OFS_DELTA) {
 338                         /*
 339                          * Deltas with relative base contain an additional
 340                          * encoding of the relative offset for the delta
 341                          * base from this object's position in the pack.
 342                          */
 343                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 344                         unsigned pos = sizeof(dheader) - 1;
 345                         dheader[pos] = ofs & 127;
 346                         while (ofs >>= 7)
 347                                 dheader[--pos] = 128 | (--ofs & 127);
 348                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 349                                 free(buf);
 350                                 return 0;
 351                         }
 352                         sha1write(f, header, hdrlen);
 353                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 354                         hdrlen += sizeof(dheader) - pos;
 355                 } else if (type == OBJ_REF_DELTA) {
 356                         /*
 357                          * Deltas with a base reference contain
 358                          * an additional 20 bytes for the base sha1.
 359                          */
 360                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 361                                 free(buf);
 362                                 return 0;
 363                         }
 364                         sha1write(f, header, hdrlen);
 365                         sha1write(f, entry->delta->idx.sha1, 20);
 366                         hdrlen += 20;
 367                 } else {
 368                         if (limit && hdrlen + datalen + 20 >= limit) {
 369                                 free(buf);
 370                                 return 0;
 371                         }
 372                         sha1write(f, header, hdrlen);
 373                 }
 374                 sha1write(f, buf, datalen);
 375                 free(buf);
 376         }
 377         else {
 378                 struct packed_git *p = entry->in_pack;
 379                 struct pack_window *w_curs = NULL;
 380                 struct revindex_entry *revidx;
 381                 off_t offset;
 382
 383                 if (entry->delta) {
 384                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 385                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 386                         reused_delta++;
 387                 }
 388                 hdrlen = encode_header(type, entry->size, header);
 389                 offset = entry->in_pack_offset;
 390                 revidx = find_pack_revindex(p, offset);
 391                 datalen = revidx[1].offset - offset;
 392                 if (!pack_to_stdout && p->index_version > 1 &&
 393                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
 394                         die("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 395                 offset += entry->in_pack_header_size;
 396                 datalen -= entry->in_pack_header_size;
 397                 if (type == OBJ_OFS_DELTA) {
 398                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 399                         unsigned pos = sizeof(dheader) - 1;
 400                         dheader[pos] = ofs & 127;
 401                         while (ofs >>= 7)
 402                                 dheader[--pos] = 128 | (--ofs & 127);
 403                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit)
 404                                 return 0;
 405                         sha1write(f, header, hdrlen);
 406                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 407                         hdrlen += sizeof(dheader) - pos;
 408                 } else if (type == OBJ_REF_DELTA) {
 409                         if (limit && hdrlen + 20 + datalen + 20 >= limit)
 410                                 return 0;
 411                         sha1write(f, header, hdrlen);
 412                         sha1write(f, entry->delta->idx.sha1, 20);
 413                         hdrlen += 20;
 414                 } else {
 415                         if (limit && hdrlen + datalen + 20 >= limit)
 416                                 return 0;
 417                         sha1write(f, header, hdrlen);
 418                 }
 419
 420                 if (!pack_to_stdout && p->index_version == 1 &&
 421                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
 422                         die("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 423                 copy_pack_data(f, p, &w_curs, offset, datalen);
 424                 unuse_pack(&w_curs);
 425                 reused++;
 426         }
 427         if (usable_delta)
 428                 written_delta++;
 429         written++;
 430         if (!pack_to_stdout)
 431                 entry->idx.crc32 = crc32_end(f);
 432         return hdrlen + datalen;
 433 }
 434
 435 static off_t write_one(struct sha1file *f,
 436                                struct object_entry *e,
 437                                off_t offset)
 438 {
 439         unsigned long size;
 440
 441         /* offset is non zero if object is written already. */
 442         if (e->idx.offset || e->preferred_base)
 443                 return offset;
 444
 445         /* if we are deltified, write out base object first. */
 446         if (e->delta) {
 447                 offset = write_one(f, e->delta, offset);
 448                 if (!offset)
 449                         return 0;
 450         }
 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         return offset + size;
 464 }
 465
 466 /* forward declaration for write_pack_file */
 467 static int adjust_perm(const char *path, mode_t mode);
 468
 469 static void write_pack_file(void)
 470 {
 471         uint32_t i = 0, j;
 472         struct sha1file *f;
 473         off_t offset, offset_one, last_obj_offset = 0;
 474         struct pack_header hdr;
 475         uint32_t nr_remaining = nr_result;
 476         time_t last_mtime = 0;
 477
 478         if (progress > pack_to_stdout)
 479                 progress_state = start_progress("Writing objects", nr_result);
 480         written_list = xmalloc(nr_objects * sizeof(*written_list));
 481
 482         do {
 483                 unsigned char sha1[20];
 484                 char *pack_tmp_name = NULL;
 485
 486                 if (pack_to_stdout) {
 487                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 488                 } else {
 489                         char tmpname[PATH_MAX];
 490                         int fd;
 491                         snprintf(tmpname, sizeof(tmpname),
 492                                  "%s/tmp_pack_XXXXXX", get_object_directory());
 493                         fd = xmkstemp(tmpname);
 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                         last_obj_offset = offset;
 506                         offset_one = write_one(f, objects + i, offset);
 507                         if (!offset_one)
 508                                 break;
 509                         offset = offset_one;
 510                         display_progress(progress_state, written);
 511                 }
 512
 513                 /*
 514                  * Did we write the wrong # entries in the header?
 515                  * If so, rewrite it like in fast-import
 516                  */
 517                 if (pack_to_stdout || nr_written == nr_remaining) {
 518                         unsigned flags = pack_to_stdout ? CSUM_CLOSE : CSUM_FSYNC;
 519                         sha1close(f, sha1, flags);
 520                 } else {
 521                         int fd = sha1close(f, NULL, 0);
 522                         fixup_pack_header_footer(fd, sha1, pack_tmp_name, nr_written);
 523                         fsync_or_die(fd, pack_tmp_name);
 524                         close(fd);
 525                 }
 526
 527                 if (!pack_to_stdout) {
 528                         mode_t mode = umask(0);
 529                         struct stat st;
 530                         char *idx_tmp_name, tmpname[PATH_MAX];
 531
 532                         umask(mode);
 533                         mode = 0444 & ~mode;
 534
 535                         idx_tmp_name = write_idx_file(NULL, written_list,
 536                                                       nr_written, sha1);
 537
 538                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 539                                  base_name, sha1_to_hex(sha1));
 540                         if (adjust_perm(pack_tmp_name, mode))
 541                                 die("unable to make temporary pack file readable: %s",
 542                                     strerror(errno));
 543                         if (rename(pack_tmp_name, tmpname))
 544                                 die("unable to rename temporary pack file: %s",
 545                                     strerror(errno));
 546
 547                         /*
 548                          * Packs are runtime accessed in their mtime
 549                          * order since newer packs are more likely to contain
 550                          * younger objects.  So if we are creating multiple
 551                          * packs then we should modify the mtime of later ones
 552                          * to preserve this property.
 553                          */
 554                         if (stat(tmpname, &st) < 0) {
 555                                 warning("failed to stat %s: %s",
 556                                         tmpname, strerror(errno));
 557                         } else if (!last_mtime) {
 558                                 last_mtime = st.st_mtime;
 559                         } else {
 560                                 struct utimbuf utb;
 561                                 utb.actime = st.st_atime;
 562                                 utb.modtime = --last_mtime;
 563                                 if (utime(tmpname, &utb) < 0)
 564                                         warning("failed utime() on %s: %s",
 565                                                 tmpname, strerror(errno));
 566                         }
 567
 568                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 569                                  base_name, sha1_to_hex(sha1));
 570                         if (adjust_perm(idx_tmp_name, mode))
 571                                 die("unable to make temporary index file readable: %s",
 572                                     strerror(errno));
 573                         if (rename(idx_tmp_name, tmpname))
 574                                 die("unable to rename temporary index file: %s",
 575                                     strerror(errno));
 576
 577                         free(idx_tmp_name);
 578                         free(pack_tmp_name);
 579                         puts(sha1_to_hex(sha1));
 580                 }
 581
 582                 /* mark written objects as written to previous pack */
 583                 for (j = 0; j < nr_written; j++) {
 584                         written_list[j]->offset = (off_t)-1;
 585                 }
 586                 nr_remaining -= nr_written;
 587         } while (nr_remaining && i < nr_objects);
 588
 589         free(written_list);
 590         stop_progress(&progress_state);
 591         if (written != nr_result)
 592                 die("wrote %u objects while expecting %u", written, nr_result);
 593         /*
 594          * We have scanned through [0 ... i).  Since we have written
 595          * the correct number of objects,  the remaining [i ... nr_objects)
 596          * items must be either already written (due to out-of-order delta base)
 597          * or a preferred base.  Count those which are neither and complain if any.
 598          */
 599         for (j = 0; i < nr_objects; i++) {
 600                 struct object_entry *e = objects + i;
 601                 j += !e->idx.offset && !e->preferred_base;
 602         }
 603         if (j)
 604                 die("wrote %u objects as expected but %u unwritten", written, j);
 605 }
 606
 607 static int locate_object_entry_hash(const unsigned char *sha1)
 608 {
 609         int i;
 610         unsigned int ui;
 611         memcpy(&ui, sha1, sizeof(unsigned int));
 612         i = ui % object_ix_hashsz;
 613         while (0 < object_ix[i]) {
 614                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 615                         return i;
 616                 if (++i == object_ix_hashsz)
 617                         i = 0;
 618         }
 619         return -1 - i;
 620 }
 621
 622 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 623 {
 624         int i;
 625
 626         if (!object_ix_hashsz)
 627                 return NULL;
 628
 629         i = locate_object_entry_hash(sha1);
 630         if (0 <= i)
 631                 return &objects[object_ix[i]-1];
 632         return NULL;
 633 }
 634
 635 static void rehash_objects(void)
 636 {
 637         uint32_t i;
 638         struct object_entry *oe;
 639
 640         object_ix_hashsz = nr_objects * 3;
 641         if (object_ix_hashsz < 1024)
 642                 object_ix_hashsz = 1024;
 643         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 644         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 645         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 646                 int ix = locate_object_entry_hash(oe->idx.sha1);
 647                 if (0 <= ix)
 648                         continue;
 649                 ix = -1 - ix;
 650                 object_ix[ix] = i + 1;
 651         }
 652 }
 653
 654 static unsigned name_hash(const char *name)
 655 {
 656         unsigned char c;
 657         unsigned hash = 0;
 658
 659         if (!name)
 660                 return 0;
 661
 662         /*
 663          * This effectively just creates a sortable number from the
 664          * last sixteen non-whitespace characters. Last characters
 665          * count "most", so things that end in ".c" sort together.
 666          */
 667         while ((c = *name++) != 0) {
 668                 if (isspace(c))
 669                         continue;
 670                 hash = (hash >> 2) + (c << 24);
 671         }
 672         return hash;
 673 }
 674
 675 static void setup_delta_attr_check(struct git_attr_check *check)
 676 {
 677         static struct git_attr *attr_delta;
 678
 679         if (!attr_delta)
 680                 attr_delta = git_attr("delta", 5);
 681
 682         check[0].attr = attr_delta;
 683 }
 684
 685 static int no_try_delta(const char *path)
 686 {
 687         struct git_attr_check check[1];
 688
 689         setup_delta_attr_check(check);
 690         if (git_checkattr(path, ARRAY_SIZE(check), check))
 691                 return 0;
 692         if (ATTR_FALSE(check->value))
 693                 return 1;
 694         return 0;
 695 }
 696
 697 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 698                             const char *name, int exclude)
 699 {
 700         struct object_entry *entry;
 701         struct packed_git *p, *found_pack = NULL;
 702         off_t found_offset = 0;
 703         int ix;
 704         unsigned hash = name_hash(name);
 705
 706         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 707         if (ix >= 0) {
 708                 if (exclude) {
 709                         entry = objects + object_ix[ix] - 1;
 710                         if (!entry->preferred_base)
 711                                 nr_result--;
 712                         entry->preferred_base = 1;
 713                 }
 714                 return 0;
 715         }
 716
 717         for (p = packed_git; p; p = p->next) {
 718                 off_t offset = find_pack_entry_one(sha1, p);
 719                 if (offset) {
 720                         if (!found_pack) {
 721                                 found_offset = offset;
 722                                 found_pack = p;
 723                         }
 724                         if (exclude)
 725                                 break;
 726                         if (incremental)
 727                                 return 0;
 728                         if (local && !p->pack_local)
 729                                 return 0;
 730                 }
 731         }
 732
 733         if (nr_objects >= nr_alloc) {
 734                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 735                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 736         }
 737
 738         entry = objects + nr_objects++;
 739         memset(entry, 0, sizeof(*entry));
 740         hashcpy(entry->idx.sha1, sha1);
 741         entry->hash = hash;
 742         if (type)
 743                 entry->type = type;
 744         if (exclude)
 745                 entry->preferred_base = 1;
 746         else
 747                 nr_result++;
 748         if (found_pack) {
 749                 entry->in_pack = found_pack;
 750                 entry->in_pack_offset = found_offset;
 751         }
 752
 753         if (object_ix_hashsz * 3 <= nr_objects * 4)
 754                 rehash_objects();
 755         else
 756                 object_ix[-1 - ix] = nr_objects;
 757
 758         display_progress(progress_state, nr_objects);
 759
 760         if (name && no_try_delta(name))
 761                 entry->no_try_delta = 1;
 762
 763         return 1;
 764 }
 765
 766 struct pbase_tree_cache {
 767         unsigned char sha1[20];
 768         int ref;
 769         int temporary;
 770         void *tree_data;
 771         unsigned long tree_size;
 772 };
 773
 774 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 775 static int pbase_tree_cache_ix(const unsigned char *sha1)
 776 {
 777         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 778 }
 779 static int pbase_tree_cache_ix_incr(int ix)
 780 {
 781         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 782 }
 783
 784 static struct pbase_tree {
 785         struct pbase_tree *next;
 786         /* This is a phony "cache" entry; we are not
 787          * going to evict it nor find it through _get()
 788          * mechanism -- this is for the toplevel node that
 789          * would almost always change with any commit.
 790          */
 791         struct pbase_tree_cache pcache;
 792 } *pbase_tree;
 793
 794 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 795 {
 796         struct pbase_tree_cache *ent, *nent;
 797         void *data;
 798         unsigned long size;
 799         enum object_type type;
 800         int neigh;
 801         int my_ix = pbase_tree_cache_ix(sha1);
 802         int available_ix = -1;
 803
 804         /* pbase-tree-cache acts as a limited hashtable.
 805          * your object will be found at your index or within a few
 806          * slots after that slot if it is cached.
 807          */
 808         for (neigh = 0; neigh < 8; neigh++) {
 809                 ent = pbase_tree_cache[my_ix];
 810                 if (ent && !hashcmp(ent->sha1, sha1)) {
 811                         ent->ref++;
 812                         return ent;
 813                 }
 814                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 815                          ((0 <= available_ix) &&
 816                           (!ent && pbase_tree_cache[available_ix])))
 817                         available_ix = my_ix;
 818                 if (!ent)
 819                         break;
 820                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 821         }
 822
 823         /* Did not find one.  Either we got a bogus request or
 824          * we need to read and perhaps cache.
 825          */
 826         data = read_sha1_file(sha1, &type, &size);
 827         if (!data)
 828                 return NULL;
 829         if (type != OBJ_TREE) {
 830                 free(data);
 831                 return NULL;
 832         }
 833
 834         /* We need to either cache or return a throwaway copy */
 835
 836         if (available_ix < 0)
 837                 ent = NULL;
 838         else {
 839                 ent = pbase_tree_cache[available_ix];
 840                 my_ix = available_ix;
 841         }
 842
 843         if (!ent) {
 844                 nent = xmalloc(sizeof(*nent));
 845                 nent->temporary = (available_ix < 0);
 846         }
 847         else {
 848                 /* evict and reuse */
 849                 free(ent->tree_data);
 850                 nent = ent;
 851         }
 852         hashcpy(nent->sha1, sha1);
 853         nent->tree_data = data;
 854         nent->tree_size = size;
 855         nent->ref = 1;
 856         if (!nent->temporary)
 857                 pbase_tree_cache[my_ix] = nent;
 858         return nent;
 859 }
 860
 861 static void pbase_tree_put(struct pbase_tree_cache *cache)
 862 {
 863         if (!cache->temporary) {
 864                 cache->ref--;
 865                 return;
 866         }
 867         free(cache->tree_data);
 868         free(cache);
 869 }
 870
 871 static int name_cmp_len(const char *name)
 872 {
 873         int i;
 874         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 875                 ;
 876         return i;
 877 }
 878
 879 static void add_pbase_object(struct tree_desc *tree,
 880                              const char *name,
 881                              int cmplen,
 882                              const char *fullname)
 883 {
 884         struct name_entry entry;
 885         int cmp;
 886
 887         while (tree_entry(tree,&entry)) {
 888                 if (S_ISGITLINK(entry.mode))
 889                         continue;
 890                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 891                       memcmp(name, entry.path, cmplen);
 892                 if (cmp > 0)
 893                         continue;
 894                 if (cmp < 0)
 895                         return;
 896                 if (name[cmplen] != '/') {
 897                         add_object_entry(entry.sha1,
 898                                          object_type(entry.mode),
 899                                          fullname, 1);
 900                         return;
 901                 }
 902                 if (S_ISDIR(entry.mode)) {
 903                         struct tree_desc sub;
 904                         struct pbase_tree_cache *tree;
 905                         const char *down = name+cmplen+1;
 906                         int downlen = name_cmp_len(down);
 907
 908                         tree = pbase_tree_get(entry.sha1);
 909                         if (!tree)
 910                                 return;
 911                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 912
 913                         add_pbase_object(&sub, down, downlen, fullname);
 914                         pbase_tree_put(tree);
 915                 }
 916         }
 917 }
 918
 919 static unsigned *done_pbase_paths;
 920 static int done_pbase_paths_num;
 921 static int done_pbase_paths_alloc;
 922 static int done_pbase_path_pos(unsigned hash)
 923 {
 924         int lo = 0;
 925         int hi = done_pbase_paths_num;
 926         while (lo < hi) {
 927                 int mi = (hi + lo) / 2;
 928                 if (done_pbase_paths[mi] == hash)
 929                         return mi;
 930                 if (done_pbase_paths[mi] < hash)
 931                         hi = mi;
 932                 else
 933                         lo = mi + 1;
 934         }
 935         return -lo-1;
 936 }
 937
 938 static int check_pbase_path(unsigned hash)
 939 {
 940         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 941         if (0 <= pos)
 942                 return 1;
 943         pos = -pos - 1;
 944         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 945                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 946                 done_pbase_paths = xrealloc(done_pbase_paths,
 947                                             done_pbase_paths_alloc *
 948                                             sizeof(unsigned));
 949         }
 950         done_pbase_paths_num++;
 951         if (pos < done_pbase_paths_num)
 952                 memmove(done_pbase_paths + pos + 1,
 953                         done_pbase_paths + pos,
 954                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 955         done_pbase_paths[pos] = hash;
 956         return 0;
 957 }
 958
 959 static void add_preferred_base_object(const char *name)
 960 {
 961         struct pbase_tree *it;
 962         int cmplen;
 963         unsigned hash = name_hash(name);
 964
 965         if (!num_preferred_base || check_pbase_path(hash))
 966                 return;
 967
 968         cmplen = name_cmp_len(name);
 969         for (it = pbase_tree; it; it = it->next) {
 970                 if (cmplen == 0) {
 971                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 972                 }
 973                 else {
 974                         struct tree_desc tree;
 975                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 976                         add_pbase_object(&tree, name, cmplen, name);
 977                 }
 978         }
 979 }
 980
 981 static void add_preferred_base(unsigned char *sha1)
 982 {
 983         struct pbase_tree *it;
 984         void *data;
 985         unsigned long size;
 986         unsigned char tree_sha1[20];
 987
 988         if (window <= num_preferred_base++)
 989                 return;
 990
 991         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 992         if (!data)
 993                 return;
 994
 995         for (it = pbase_tree; it; it = it->next) {
 996                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 997                         free(data);
 998                         return;
 999                 }
1000         }
1001
1002         it = xcalloc(1, sizeof(*it));
1003         it->next = pbase_tree;
1004         pbase_tree = it;
1005
1006         hashcpy(it->pcache.sha1, tree_sha1);
1007         it->pcache.tree_data = data;
1008         it->pcache.tree_size = size;
1009 }
1010
1011 static void check_object(struct object_entry *entry)
1012 {
1013         if (entry->in_pack) {
1014                 struct packed_git *p = entry->in_pack;
1015                 struct pack_window *w_curs = NULL;
1016                 const unsigned char *base_ref = NULL;
1017                 struct object_entry *base_entry;
1018                 unsigned long used, used_0;
1019                 unsigned int avail;
1020                 off_t ofs;
1021                 unsigned char *buf, c;
1022
1023                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1024
1025                 /*
1026                  * We want in_pack_type even if we do not reuse delta
1027                  * since non-delta representations could still be reused.
1028                  */
1029                 used = unpack_object_header_gently(buf, avail,
1030                                                    &entry->in_pack_type,
1031                                                    &entry->size);
1032
1033                 /*
1034                  * Determine if this is a delta and if so whether we can
1035                  * reuse it or not.  Otherwise let's find out as cheaply as
1036                  * possible what the actual type and size for this object is.
1037                  */
1038                 switch (entry->in_pack_type) {
1039                 default:
1040                         /* Not a delta hence we've already got all we need. */
1041                         entry->type = entry->in_pack_type;
1042                         entry->in_pack_header_size = used;
1043                         unuse_pack(&w_curs);
1044                         return;
1045                 case OBJ_REF_DELTA:
1046                         if (reuse_delta && !entry->preferred_base)
1047                                 base_ref = use_pack(p, &w_curs,
1048                                                 entry->in_pack_offset + used, NULL);
1049                         entry->in_pack_header_size = used + 20;
1050                         break;
1051                 case OBJ_OFS_DELTA:
1052                         buf = use_pack(p, &w_curs,
1053                                        entry->in_pack_offset + used, NULL);
1054                         used_0 = 0;
1055                         c = buf[used_0++];
1056                         ofs = c & 127;
1057                         while (c & 128) {
1058                                 ofs += 1;
1059                                 if (!ofs || MSB(ofs, 7))
1060                                         die("delta base offset overflow in pack for %s",
1061                                             sha1_to_hex(entry->idx.sha1));
1062                                 c = buf[used_0++];
1063                                 ofs = (ofs << 7) + (c & 127);
1064                         }
1065                         if (ofs >= entry->in_pack_offset)
1066                                 die("delta base offset out of bound for %s",
1067                                     sha1_to_hex(entry->idx.sha1));
1068                         ofs = entry->in_pack_offset - ofs;
1069                         if (reuse_delta && !entry->preferred_base) {
1070                                 struct revindex_entry *revidx;
1071                                 revidx = find_pack_revindex(p, ofs);
1072                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1073                         }
1074                         entry->in_pack_header_size = used + used_0;
1075                         break;
1076                 }
1077
1078                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1079                         /*
1080                          * If base_ref was set above that means we wish to
1081                          * reuse delta data, and we even found that base
1082                          * in the list of objects we want to pack. Goodie!
1083                          *
1084                          * Depth value does not matter - find_deltas() will
1085                          * never consider reused delta as the base object to
1086                          * deltify other objects against, in order to avoid
1087                          * circular deltas.
1088                          */
1089                         entry->type = entry->in_pack_type;
1090                         entry->delta = base_entry;
1091                         entry->delta_sibling = base_entry->delta_child;
1092                         base_entry->delta_child = entry;
1093                         unuse_pack(&w_curs);
1094                         return;
1095                 }
1096
1097                 if (entry->type) {
1098                         /*
1099                          * This must be a delta and we already know what the
1100                          * final object type is.  Let's extract the actual
1101                          * object size from the delta header.
1102                          */
1103                         entry->size = get_size_from_delta(p, &w_curs,
1104                                         entry->in_pack_offset + entry->in_pack_header_size);
1105                         unuse_pack(&w_curs);
1106                         return;
1107                 }
1108
1109                 /*
1110                  * No choice but to fall back to the recursive delta walk
1111                  * with sha1_object_info() to find about the object type
1112                  * at this point...
1113                  */
1114                 unuse_pack(&w_curs);
1115         }
1116
1117         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1118         if (entry->type < 0)
1119                 die("unable to get type of object %s",
1120                     sha1_to_hex(entry->idx.sha1));
1121 }
1122
1123 static int pack_offset_sort(const void *_a, const void *_b)
1124 {
1125         const struct object_entry *a = *(struct object_entry **)_a;
1126         const struct object_entry *b = *(struct object_entry **)_b;
1127
1128         /* avoid filesystem trashing with loose objects */
1129         if (!a->in_pack && !b->in_pack)
1130                 return hashcmp(a->idx.sha1, b->idx.sha1);
1131
1132         if (a->in_pack < b->in_pack)
1133                 return -1;
1134         if (a->in_pack > b->in_pack)
1135                 return 1;
1136         return a->in_pack_offset < b->in_pack_offset ? -1 :
1137                         (a->in_pack_offset > b->in_pack_offset);
1138 }
1139
1140 static void get_object_details(void)
1141 {
1142         uint32_t i;
1143         struct object_entry **sorted_by_offset;
1144
1145         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1146         for (i = 0; i < nr_objects; i++)
1147                 sorted_by_offset[i] = objects + i;
1148         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1149
1150         init_pack_revindex();
1151
1152         for (i = 0; i < nr_objects; i++)
1153                 check_object(sorted_by_offset[i]);
1154
1155         free(sorted_by_offset);
1156 }
1157
1158 /*
1159  * We search for deltas in a list sorted by type, by filename hash, and then
1160  * by size, so that we see progressively smaller and smaller files.
1161  * That's because we prefer deltas to be from the bigger file
1162  * to the smaller -- deletes are potentially cheaper, but perhaps
1163  * more importantly, the bigger file is likely the more recent
1164  * one.  The deepest deltas are therefore the oldest objects which are
1165  * less susceptible to be accessed often.
1166  */
1167 static int type_size_sort(const void *_a, const void *_b)
1168 {
1169         const struct object_entry *a = *(struct object_entry **)_a;
1170         const struct object_entry *b = *(struct object_entry **)_b;
1171
1172         if (a->type > b->type)
1173                 return -1;
1174         if (a->type < b->type)
1175                 return 1;
1176         if (a->hash > b->hash)
1177                 return -1;
1178         if (a->hash < b->hash)
1179                 return 1;
1180         if (a->preferred_base > b->preferred_base)
1181                 return -1;
1182         if (a->preferred_base < b->preferred_base)
1183                 return 1;
1184         if (a->size > b->size)
1185                 return -1;
1186         if (a->size < b->size)
1187                 return 1;
1188         return a < b ? -1 : (a > b);  /* newest first */
1189 }
1190
1191 struct unpacked {
1192         struct object_entry *entry;
1193         void *data;
1194         struct delta_index *index;
1195         unsigned depth;
1196 };
1197
1198 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1199                            unsigned long delta_size)
1200 {
1201         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1202                 return 0;
1203
1204         if (delta_size < cache_max_small_delta_size)
1205                 return 1;
1206
1207         /* cache delta, if objects are large enough compared to delta size */
1208         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1209                 return 1;
1210
1211         return 0;
1212 }
1213
1214 #ifdef THREADED_DELTA_SEARCH
1215
1216 static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1217 #define read_lock()             pthread_mutex_lock(&read_mutex)
1218 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1219
1220 static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1221 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1222 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1223
1224 static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1225 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1226 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1227
1228 #else
1229
1230 #define read_lock()             (void)0
1231 #define read_unlock()           (void)0
1232 #define cache_lock()            (void)0
1233 #define cache_unlock()          (void)0
1234 #define progress_lock()         (void)0
1235 #define progress_unlock()       (void)0
1236
1237 #endif
1238
1239 static int try_delta(struct unpacked *trg, struct unpacked *src,
1240                      unsigned max_depth, unsigned long *mem_usage)
1241 {
1242         struct object_entry *trg_entry = trg->entry;
1243         struct object_entry *src_entry = src->entry;
1244         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1245         unsigned ref_depth;
1246         enum object_type type;
1247         void *delta_buf;
1248
1249         /* Don't bother doing diffs between different types */
1250         if (trg_entry->type != src_entry->type)
1251                 return -1;
1252
1253         /*
1254          * We do not bother to try a delta that we discarded
1255          * on an earlier try, but only when reusing delta data.
1256          */
1257         if (reuse_delta && trg_entry->in_pack &&
1258             trg_entry->in_pack == src_entry->in_pack &&
1259             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1260             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1261                 return 0;
1262
1263         /* Let's not bust the allowed depth. */
1264         if (src->depth >= max_depth)
1265                 return 0;
1266
1267         /* Now some size filtering heuristics. */
1268         trg_size = trg_entry->size;
1269         if (!trg_entry->delta) {
1270                 max_size = trg_size/2 - 20;
1271                 ref_depth = 1;
1272         } else {
1273                 max_size = trg_entry->delta_size;
1274                 ref_depth = trg->depth;
1275         }
1276         max_size = max_size * (max_depth - src->depth) /
1277                                                 (max_depth - ref_depth + 1);
1278         if (max_size == 0)
1279                 return 0;
1280         src_size = src_entry->size;
1281         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1282         if (sizediff >= max_size)
1283                 return 0;
1284         if (trg_size < src_size / 32)
1285                 return 0;
1286
1287         /* Load data if not already done */
1288         if (!trg->data) {
1289                 read_lock();
1290                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1291                 read_unlock();
1292                 if (!trg->data)
1293                         die("object %s cannot be read",
1294                             sha1_to_hex(trg_entry->idx.sha1));
1295                 if (sz != trg_size)
1296                         die("object %s inconsistent object length (%lu vs %lu)",
1297                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1298                 *mem_usage += sz;
1299         }
1300         if (!src->data) {
1301                 read_lock();
1302                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1303                 read_unlock();
1304                 if (!src->data)
1305                         die("object %s cannot be read",
1306                             sha1_to_hex(src_entry->idx.sha1));
1307                 if (sz != src_size)
1308                         die("object %s inconsistent object length (%lu vs %lu)",
1309                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1310                 *mem_usage += sz;
1311         }
1312         if (!src->index) {
1313                 src->index = create_delta_index(src->data, src_size);
1314                 if (!src->index) {
1315                         static int warned = 0;
1316                         if (!warned++)
1317                                 warning("suboptimal pack - out of memory");
1318                         return 0;
1319                 }
1320                 *mem_usage += sizeof_delta_index(src->index);
1321         }
1322
1323         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1324         if (!delta_buf)
1325                 return 0;
1326
1327         if (trg_entry->delta) {
1328                 /* Prefer only shallower same-sized deltas. */
1329                 if (delta_size == trg_entry->delta_size &&
1330                     src->depth + 1 >= trg->depth) {
1331                         free(delta_buf);
1332                         return 0;
1333                 }
1334         }
1335
1336         /*
1337          * Handle memory allocation outside of the cache
1338          * accounting lock.  Compiler will optimize the strangeness
1339          * away when THREADED_DELTA_SEARCH is not defined.
1340          */
1341         free(trg_entry->delta_data);
1342         cache_lock();
1343         if (trg_entry->delta_data) {
1344                 delta_cache_size -= trg_entry->delta_size;
1345                 trg_entry->delta_data = NULL;
1346         }
1347         if (delta_cacheable(src_size, trg_size, delta_size)) {
1348                 delta_cache_size += delta_size;
1349                 cache_unlock();
1350                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1351         } else {
1352                 cache_unlock();
1353                 free(delta_buf);
1354         }
1355
1356         trg_entry->delta = src_entry;
1357         trg_entry->delta_size = delta_size;
1358         trg->depth = src->depth + 1;
1359
1360         return 1;
1361 }
1362
1363 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1364 {
1365         struct object_entry *child = me->delta_child;
1366         unsigned int m = n;
1367         while (child) {
1368                 unsigned int c = check_delta_limit(child, n + 1);
1369                 if (m < c)
1370                         m = c;
1371                 child = child->delta_sibling;
1372         }
1373         return m;
1374 }
1375
1376 static unsigned long free_unpacked(struct unpacked *n)
1377 {
1378         unsigned long freed_mem = sizeof_delta_index(n->index);
1379         free_delta_index(n->index);
1380         n->index = NULL;
1381         if (n->data) {
1382                 freed_mem += n->entry->size;
1383                 free(n->data);
1384                 n->data = NULL;
1385         }
1386         n->entry = NULL;
1387         n->depth = 0;
1388         return freed_mem;
1389 }
1390
1391 static void find_deltas(struct object_entry **list, unsigned *list_size,
1392                         int window, int depth, unsigned *processed)
1393 {
1394         uint32_t i, idx = 0, count = 0;
1395         unsigned int array_size = window * sizeof(struct unpacked);
1396         struct unpacked *array;
1397         unsigned long mem_usage = 0;
1398
1399         array = xmalloc(array_size);
1400         memset(array, 0, array_size);
1401
1402         for (;;) {
1403                 struct object_entry *entry = *list++;
1404                 struct unpacked *n = array + idx;
1405                 int j, max_depth, best_base = -1;
1406
1407                 progress_lock();
1408                 if (!*list_size) {
1409                         progress_unlock();
1410                         break;
1411                 }
1412                 (*list_size)--;
1413                 if (!entry->preferred_base) {
1414                         (*processed)++;
1415                         display_progress(progress_state, *processed);
1416                 }
1417                 progress_unlock();
1418
1419                 mem_usage -= free_unpacked(n);
1420                 n->entry = entry;
1421
1422                 while (window_memory_limit &&
1423                        mem_usage > window_memory_limit &&
1424                        count > 1) {
1425                         uint32_t tail = (idx + window - count) % window;
1426                         mem_usage -= free_unpacked(array + tail);
1427                         count--;
1428                 }
1429
1430                 /* We do not compute delta to *create* objects we are not
1431                  * going to pack.
1432                  */
1433                 if (entry->preferred_base)
1434                         goto next;
1435
1436                 /*
1437                  * If the current object is at pack edge, take the depth the
1438                  * objects that depend on the current object into account
1439                  * otherwise they would become too deep.
1440                  */
1441                 max_depth = depth;
1442                 if (entry->delta_child) {
1443                         max_depth -= check_delta_limit(entry, 0);
1444                         if (max_depth <= 0)
1445                                 goto next;
1446                 }
1447
1448                 j = window;
1449                 while (--j > 0) {
1450                         int ret;
1451                         uint32_t other_idx = idx + j;
1452                         struct unpacked *m;
1453                         if (other_idx >= window)
1454                                 other_idx -= window;
1455                         m = array + other_idx;
1456                         if (!m->entry)
1457                                 break;
1458                         ret = try_delta(n, m, max_depth, &mem_usage);
1459                         if (ret < 0)
1460                                 break;
1461                         else if (ret > 0)
1462                                 best_base = other_idx;
1463                 }
1464
1465                 /*
1466                  * If we decided to cache the delta data, then it is best
1467                  * to compress it right away.  First because we have to do
1468                  * it anyway, and doing it here while we're threaded will
1469                  * save a lot of time in the non threaded write phase,
1470                  * as well as allow for caching more deltas within
1471                  * the same cache size limit.
1472                  * ...
1473                  * But only if not writing to stdout, since in that case
1474                  * the network is most likely throttling writes anyway,
1475                  * and therefore it is best to go to the write phase ASAP
1476                  * instead, as we can afford spending more time compressing
1477                  * between writes at that moment.
1478                  */
1479                 if (entry->delta_data && !pack_to_stdout) {
1480                         entry->z_delta_size = do_compress(&entry->delta_data,
1481                                                           entry->delta_size);
1482                         cache_lock();
1483                         delta_cache_size -= entry->delta_size;
1484                         delta_cache_size += entry->z_delta_size;
1485                         cache_unlock();
1486                 }
1487
1488                 /* if we made n a delta, and if n is already at max
1489                  * depth, leaving it in the window is pointless.  we
1490                  * should evict it first.
1491                  */
1492                 if (entry->delta && max_depth <= n->depth)
1493                         continue;
1494
1495                 /*
1496                  * Move the best delta base up in the window, after the
1497                  * currently deltified object, to keep it longer.  It will
1498                  * be the first base object to be attempted next.
1499                  */
1500                 if (entry->delta) {
1501                         struct unpacked swap = array[best_base];
1502                         int dist = (window + idx - best_base) % window;
1503                         int dst = best_base;
1504                         while (dist--) {
1505                                 int src = (dst + 1) % window;
1506                                 array[dst] = array[src];
1507                                 dst = src;
1508                         }
1509                         array[dst] = swap;
1510                 }
1511
1512                 next:
1513                 idx++;
1514                 if (count + 1 < window)
1515                         count++;
1516                 if (idx >= window)
1517                         idx = 0;
1518         }
1519
1520         for (i = 0; i < window; ++i) {
1521                 free_delta_index(array[i].index);
1522                 free(array[i].data);
1523         }
1524         free(array);
1525 }
1526
1527 #ifdef THREADED_DELTA_SEARCH
1528
1529 /*
1530  * The main thread waits on the condition that (at least) one of the workers
1531  * has stopped working (which is indicated in the .working member of
1532  * struct thread_params).
1533  * When a work thread has completed its work, it sets .working to 0 and
1534  * signals the main thread and waits on the condition that .data_ready
1535  * becomes 1.
1536  */
1537
1538 struct thread_params {
1539         pthread_t thread;
1540         struct object_entry **list;
1541         unsigned list_size;
1542         unsigned remaining;
1543         int window;
1544         int depth;
1545         int working;
1546         int data_ready;
1547         pthread_mutex_t mutex;
1548         pthread_cond_t cond;
1549         unsigned *processed;
1550 };
1551
1552 static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
1553
1554 static void *threaded_find_deltas(void *arg)
1555 {
1556         struct thread_params *me = arg;
1557
1558         while (me->remaining) {
1559                 find_deltas(me->list, &me->remaining,
1560                             me->window, me->depth, me->processed);
1561
1562                 progress_lock();
1563                 me->working = 0;
1564                 pthread_cond_signal(&progress_cond);
1565                 progress_unlock();
1566
1567                 /*
1568                  * We must not set ->data_ready before we wait on the
1569                  * condition because the main thread may have set it to 1
1570                  * before we get here. In order to be sure that new
1571                  * work is available if we see 1 in ->data_ready, it
1572                  * was initialized to 0 before this thread was spawned
1573                  * and we reset it to 0 right away.
1574                  */
1575                 pthread_mutex_lock(&me->mutex);
1576                 while (!me->data_ready)
1577                         pthread_cond_wait(&me->cond, &me->mutex);
1578                 me->data_ready = 0;
1579                 pthread_mutex_unlock(&me->mutex);
1580         }
1581         /* leave ->working 1 so that this doesn't get more work assigned */
1582         return NULL;
1583 }
1584
1585 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1586                            int window, int depth, unsigned *processed)
1587 {
1588         struct thread_params p[delta_search_threads];
1589         int i, ret, active_threads = 0;
1590
1591         if (delta_search_threads <= 1) {
1592                 find_deltas(list, &list_size, window, depth, processed);
1593                 return;
1594         }
1595
1596         /* Partition the work amongst work threads. */
1597         for (i = 0; i < delta_search_threads; i++) {
1598                 unsigned sub_size = list_size / (delta_search_threads - i);
1599
1600                 p[i].window = window;
1601                 p[i].depth = depth;
1602                 p[i].processed = processed;
1603                 p[i].working = 1;
1604                 p[i].data_ready = 0;
1605
1606                 /* try to split chunks on "path" boundaries */
1607                 while (sub_size && sub_size < list_size &&
1608                        list[sub_size]->hash &&
1609                        list[sub_size]->hash == list[sub_size-1]->hash)
1610                         sub_size++;
1611
1612                 p[i].list = list;
1613                 p[i].list_size = sub_size;
1614                 p[i].remaining = sub_size;
1615
1616                 list += sub_size;
1617                 list_size -= sub_size;
1618         }
1619
1620         /* Start work threads. */
1621         for (i = 0; i < delta_search_threads; i++) {
1622                 if (!p[i].list_size)
1623                         continue;
1624                 pthread_mutex_init(&p[i].mutex, NULL);
1625                 pthread_cond_init(&p[i].cond, NULL);
1626                 ret = pthread_create(&p[i].thread, NULL,
1627                                      threaded_find_deltas, &p[i]);
1628                 if (ret)
1629                         die("unable to create thread: %s", strerror(ret));
1630                 active_threads++;
1631         }
1632
1633         /*
1634          * Now let's wait for work completion.  Each time a thread is done
1635          * with its work, we steal half of the remaining work from the
1636          * thread with the largest number of unprocessed objects and give
1637          * it to that newly idle thread.  This ensure good load balancing
1638          * until the remaining object list segments are simply too short
1639          * to be worth splitting anymore.
1640          */
1641         while (active_threads) {
1642                 struct thread_params *target = NULL;
1643                 struct thread_params *victim = NULL;
1644                 unsigned sub_size = 0;
1645
1646                 progress_lock();
1647                 for (;;) {
1648                         for (i = 0; !target && i < delta_search_threads; i++)
1649                                 if (!p[i].working)
1650                                         target = &p[i];
1651                         if (target)
1652                                 break;
1653                         pthread_cond_wait(&progress_cond, &progress_mutex);
1654                 }
1655
1656                 for (i = 0; i < delta_search_threads; i++)
1657                         if (p[i].remaining > 2*window &&
1658                             (!victim || victim->remaining < p[i].remaining))
1659                                 victim = &p[i];
1660                 if (victim) {
1661                         sub_size = victim->remaining / 2;
1662                         list = victim->list + victim->list_size - sub_size;
1663                         while (sub_size && list[0]->hash &&
1664                                list[0]->hash == list[-1]->hash) {
1665                                 list++;
1666                                 sub_size--;
1667                         }
1668                         if (!sub_size) {
1669                                 /*
1670                                  * It is possible for some "paths" to have
1671                                  * so many objects that no hash boundary
1672                                  * might be found.  Let's just steal the
1673                                  * exact half in that case.
1674                                  */
1675                                 sub_size = victim->remaining / 2;
1676                                 list -= sub_size;
1677                         }
1678                         target->list = list;
1679                         victim->list_size -= sub_size;
1680                         victim->remaining -= sub_size;
1681                 }
1682                 target->list_size = sub_size;
1683                 target->remaining = sub_size;
1684                 target->working = 1;
1685                 progress_unlock();
1686
1687                 pthread_mutex_lock(&target->mutex);
1688                 target->data_ready = 1;
1689                 pthread_cond_signal(&target->cond);
1690                 pthread_mutex_unlock(&target->mutex);
1691
1692                 if (!sub_size) {
1693                         pthread_join(target->thread, NULL);
1694                         pthread_cond_destroy(&target->cond);
1695                         pthread_mutex_destroy(&target->mutex);
1696                         active_threads--;
1697                 }
1698         }
1699 }
1700
1701 #else
1702 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1703 #endif
1704
1705 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1706 {
1707         unsigned char peeled[20];
1708
1709         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1710             !peel_ref(path, peeled)        && /* peelable? */
1711             !is_null_sha1(peeled)          && /* annotated tag? */
1712             locate_object_entry(peeled))      /* object packed? */
1713                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1714         return 0;
1715 }
1716
1717 static void prepare_pack(int window, int depth)
1718 {
1719         struct object_entry **delta_list;
1720         uint32_t i, n, nr_deltas;
1721
1722         get_object_details();
1723
1724         if (!nr_objects || !window || !depth)
1725                 return;
1726
1727         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1728         nr_deltas = n = 0;
1729
1730         for (i = 0; i < nr_objects; i++) {
1731                 struct object_entry *entry = objects + i;
1732
1733                 if (entry->delta)
1734                         /* This happens if we decided to reuse existing
1735                          * delta from a pack.  "reuse_delta &&" is implied.
1736                          */
1737                         continue;
1738
1739                 if (entry->size < 50)
1740                         continue;
1741
1742                 if (entry->no_try_delta)
1743                         continue;
1744
1745                 if (!entry->preferred_base)
1746                         nr_deltas++;
1747
1748                 delta_list[n++] = entry;
1749         }
1750
1751         if (nr_deltas && n > 1) {
1752                 unsigned nr_done = 0;
1753                 if (progress)
1754                         progress_state = start_progress("Compressing objects",
1755                                                         nr_deltas);
1756                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1757                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1758                 stop_progress(&progress_state);
1759                 if (nr_done != nr_deltas)
1760                         die("inconsistency with delta count");
1761         }
1762         free(delta_list);
1763 }
1764
1765 static int git_pack_config(const char *k, const char *v, void *cb)
1766 {
1767         if(!strcmp(k, "pack.window")) {
1768                 window = git_config_int(k, v);
1769                 return 0;
1770         }
1771         if (!strcmp(k, "pack.windowmemory")) {
1772                 window_memory_limit = git_config_ulong(k, v);
1773                 return 0;
1774         }
1775         if (!strcmp(k, "pack.depth")) {
1776                 depth = git_config_int(k, v);
1777                 return 0;
1778         }
1779         if (!strcmp(k, "pack.compression")) {
1780                 int level = git_config_int(k, v);
1781                 if (level == -1)
1782                         level = Z_DEFAULT_COMPRESSION;
1783                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1784                         die("bad pack compression level %d", level);
1785                 pack_compression_level = level;
1786                 pack_compression_seen = 1;
1787                 return 0;
1788         }
1789         if (!strcmp(k, "pack.deltacachesize")) {
1790                 max_delta_cache_size = git_config_int(k, v);
1791                 return 0;
1792         }
1793         if (!strcmp(k, "pack.deltacachelimit")) {
1794                 cache_max_small_delta_size = git_config_int(k, v);
1795                 return 0;
1796         }
1797         if (!strcmp(k, "pack.threads")) {
1798                 delta_search_threads = git_config_int(k, v);
1799                 if (delta_search_threads < 0)
1800                         die("invalid number of threads specified (%d)",
1801                             delta_search_threads);
1802 #ifndef THREADED_DELTA_SEARCH
1803                 if (delta_search_threads != 1)
1804                         warning("no threads support, ignoring %s", k);
1805 #endif
1806                 return 0;
1807         }
1808         if (!strcmp(k, "pack.indexversion")) {
1809                 pack_idx_default_version = git_config_int(k, v);
1810                 if (pack_idx_default_version > 2)
1811                         die("bad pack.indexversion=%d", pack_idx_default_version);
1812                 return 0;
1813         }
1814         if (!strcmp(k, "pack.packsizelimit")) {
1815                 pack_size_limit_cfg = git_config_ulong(k, v);
1816                 return 0;
1817         }
1818         return git_default_config(k, v, cb);
1819 }
1820
1821 static void read_object_list_from_stdin(void)
1822 {
1823         char line[40 + 1 + PATH_MAX + 2];
1824         unsigned char sha1[20];
1825
1826         for (;;) {
1827                 if (!fgets(line, sizeof(line), stdin)) {
1828                         if (feof(stdin))
1829                                 break;
1830                         if (!ferror(stdin))
1831                                 die("fgets returned NULL, not EOF, not error!");
1832                         if (errno != EINTR)
1833                                 die("fgets: %s", strerror(errno));
1834                         clearerr(stdin);
1835                         continue;
1836                 }
1837                 if (line[0] == '-') {
1838                         if (get_sha1_hex(line+1, sha1))
1839                                 die("expected edge sha1, got garbage:\n %s",
1840                                     line);
1841                         add_preferred_base(sha1);
1842                         continue;
1843                 }
1844                 if (get_sha1_hex(line, sha1))
1845                         die("expected sha1, got garbage:\n %s", line);
1846
1847                 add_preferred_base_object(line+41);
1848                 add_object_entry(sha1, 0, line+41, 0);
1849         }
1850 }
1851
1852 #define OBJECT_ADDED (1u<<20)
1853
1854 static void show_commit(struct commit *commit)
1855 {
1856         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1857         commit->object.flags |= OBJECT_ADDED;
1858 }
1859
1860 static void show_object(struct object_array_entry *p)
1861 {
1862         add_preferred_base_object(p->name);
1863         add_object_entry(p->item->sha1, p->item->type, p->name, 0);
1864         p->item->flags |= OBJECT_ADDED;
1865 }
1866
1867 static void show_edge(struct commit *commit)
1868 {
1869         add_preferred_base(commit->object.sha1);
1870 }
1871
1872 struct in_pack_object {
1873         off_t offset;
1874         struct object *object;
1875 };
1876
1877 struct in_pack {
1878         int alloc;
1879         int nr;
1880         struct in_pack_object *array;
1881 };
1882
1883 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1884 {
1885         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1886         in_pack->array[in_pack->nr].object = object;
1887         in_pack->nr++;
1888 }
1889
1890 /*
1891  * Compare the objects in the offset order, in order to emulate the
1892  * "git-rev-list --objects" output that produced the pack originally.
1893  */
1894 static int ofscmp(const void *a_, const void *b_)
1895 {
1896         struct in_pack_object *a = (struct in_pack_object *)a_;
1897         struct in_pack_object *b = (struct in_pack_object *)b_;
1898
1899         if (a->offset < b->offset)
1900                 return -1;
1901         else if (a->offset > b->offset)
1902                 return 1;
1903         else
1904                 return hashcmp(a->object->sha1, b->object->sha1);
1905 }
1906
1907 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1908 {
1909         struct packed_git *p;
1910         struct in_pack in_pack;
1911         uint32_t i;
1912
1913         memset(&in_pack, 0, sizeof(in_pack));
1914
1915         for (p = packed_git; p; p = p->next) {
1916                 const unsigned char *sha1;
1917                 struct object *o;
1918
1919                 for (i = 0; i < revs->num_ignore_packed; i++) {
1920                         if (matches_pack_name(p, revs->ignore_packed[i]))
1921                                 break;
1922                 }
1923                 if (revs->num_ignore_packed <= i)
1924                         continue;
1925                 if (open_pack_index(p))
1926                         die("cannot open pack index");
1927
1928                 ALLOC_GROW(in_pack.array,
1929                            in_pack.nr + p->num_objects,
1930                            in_pack.alloc);
1931
1932                 for (i = 0; i < p->num_objects; i++) {
1933                         sha1 = nth_packed_object_sha1(p, i);
1934                         o = lookup_unknown_object(sha1);
1935                         if (!(o->flags & OBJECT_ADDED))
1936                                 mark_in_pack_object(o, p, &in_pack);
1937                         o->flags |= OBJECT_ADDED;
1938                 }
1939         }
1940
1941         if (in_pack.nr) {
1942                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
1943                       ofscmp);
1944                 for (i = 0; i < in_pack.nr; i++) {
1945                         struct object *o = in_pack.array[i].object;
1946                         add_object_entry(o->sha1, o->type, "", 0);
1947                 }
1948         }
1949         free(in_pack.array);
1950 }
1951
1952 static void loosen_unused_packed_objects(struct rev_info *revs)
1953 {
1954         struct packed_git *p;
1955         uint32_t i;
1956         const unsigned char *sha1;
1957
1958         for (p = packed_git; p; p = p->next) {
1959                 for (i = 0; i < revs->num_ignore_packed; i++) {
1960                         if (matches_pack_name(p, revs->ignore_packed[i]))
1961                                 break;
1962                 }
1963                 if (revs->num_ignore_packed <= i)
1964                         continue;
1965
1966                 if (open_pack_index(p))
1967                         die("cannot open pack index");
1968
1969                 for (i = 0; i < p->num_objects; i++) {
1970                         sha1 = nth_packed_object_sha1(p, i);
1971                         if (!locate_object_entry(sha1))
1972                                 if (force_object_loose(sha1, p->mtime))
1973                                         die("unable to force loose object");
1974                 }
1975         }
1976 }
1977
1978 static void get_object_list(int ac, const char **av)
1979 {
1980         struct rev_info revs;
1981         char line[1000];
1982         int flags = 0;
1983
1984         init_revisions(&revs, NULL);
1985         save_commit_buffer = 0;
1986         setup_revisions(ac, av, &revs, NULL);
1987
1988         while (fgets(line, sizeof(line), stdin) != NULL) {
1989                 int len = strlen(line);
1990                 if (len && line[len - 1] == '\n')
1991                         line[--len] = 0;
1992                 if (!len)
1993                         break;
1994                 if (*line == '-') {
1995                         if (!strcmp(line, "--not")) {
1996                                 flags ^= UNINTERESTING;
1997                                 continue;
1998                         }
1999                         die("not a rev '%s'", line);
2000                 }
2001                 if (handle_revision_arg(line, &revs, flags, 1))
2002                         die("bad revision '%s'", line);
2003         }
2004
2005         if (prepare_revision_walk(&revs))
2006                 die("revision walk setup failed");
2007         mark_edges_uninteresting(revs.commits, &revs, show_edge);
2008         traverse_commit_list(&revs, show_commit, show_object);
2009
2010         if (keep_unreachable)
2011                 add_objects_in_unpacked_packs(&revs);
2012         if (unpack_unreachable)
2013                 loosen_unused_packed_objects(&revs);
2014 }
2015
2016 static int adjust_perm(const char *path, mode_t mode)
2017 {
2018         if (chmod(path, mode))
2019                 return -1;
2020         return adjust_shared_perm(path);
2021 }
2022
2023 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2024 {
2025         int use_internal_rev_list = 0;
2026         int thin = 0;
2027         uint32_t i;
2028         const char **rp_av;
2029         int rp_ac_alloc = 64;
2030         int rp_ac;
2031
2032         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2033
2034         rp_av[0] = "pack-objects";
2035         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2036         rp_ac = 2;
2037
2038         git_config(git_pack_config, NULL);
2039         if (!pack_compression_seen && core_compression_seen)
2040                 pack_compression_level = core_compression_level;
2041
2042         progress = isatty(2);
2043         for (i = 1; i < argc; i++) {
2044                 const char *arg = argv[i];
2045
2046                 if (*arg != '-')
2047                         break;
2048
2049                 if (!strcmp("--non-empty", arg)) {
2050                         non_empty = 1;
2051                         continue;
2052                 }
2053                 if (!strcmp("--local", arg)) {
2054                         local = 1;
2055                         continue;
2056                 }
2057                 if (!strcmp("--incremental", arg)) {
2058                         incremental = 1;
2059                         continue;
2060                 }
2061                 if (!prefixcmp(arg, "--compression=")) {
2062                         char *end;
2063                         int level = strtoul(arg+14, &end, 0);
2064                         if (!arg[14] || *end)
2065                                 usage(pack_usage);
2066                         if (level == -1)
2067                                 level = Z_DEFAULT_COMPRESSION;
2068                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2069                                 die("bad pack compression level %d", level);
2070                         pack_compression_level = level;
2071                         continue;
2072                 }
2073                 if (!prefixcmp(arg, "--max-pack-size=")) {
2074                         char *end;
2075                         pack_size_limit_cfg = 0;
2076                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2077                         if (!arg[16] || *end)
2078                                 usage(pack_usage);
2079                         continue;
2080                 }
2081                 if (!prefixcmp(arg, "--window=")) {
2082                         char *end;
2083                         window = strtoul(arg+9, &end, 0);
2084                         if (!arg[9] || *end)
2085                                 usage(pack_usage);
2086                         continue;
2087                 }
2088                 if (!prefixcmp(arg, "--window-memory=")) {
2089                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2090                                 usage(pack_usage);
2091                         continue;
2092                 }
2093                 if (!prefixcmp(arg, "--threads=")) {
2094                         char *end;
2095                         delta_search_threads = strtoul(arg+10, &end, 0);
2096                         if (!arg[10] || *end || delta_search_threads < 0)
2097                                 usage(pack_usage);
2098 #ifndef THREADED_DELTA_SEARCH
2099                         if (delta_search_threads != 1)
2100                                 warning("no threads support, "
2101                                         "ignoring %s", arg);
2102 #endif
2103                         continue;
2104                 }
2105                 if (!prefixcmp(arg, "--depth=")) {
2106                         char *end;
2107                         depth = strtoul(arg+8, &end, 0);
2108                         if (!arg[8] || *end)
2109                                 usage(pack_usage);
2110                         continue;
2111                 }
2112                 if (!strcmp("--progress", arg)) {
2113                         progress = 1;
2114                         continue;
2115                 }
2116                 if (!strcmp("--all-progress", arg)) {
2117                         progress = 2;
2118                         continue;
2119                 }
2120                 if (!strcmp("-q", arg)) {
2121                         progress = 0;
2122                         continue;
2123                 }
2124                 if (!strcmp("--no-reuse-delta", arg)) {
2125                         reuse_delta = 0;
2126                         continue;
2127                 }
2128                 if (!strcmp("--no-reuse-object", arg)) {
2129                         reuse_object = reuse_delta = 0;
2130                         continue;
2131                 }
2132                 if (!strcmp("--delta-base-offset", arg)) {
2133                         allow_ofs_delta = 1;
2134                         continue;
2135                 }
2136                 if (!strcmp("--stdout", arg)) {
2137                         pack_to_stdout = 1;
2138                         continue;
2139                 }
2140                 if (!strcmp("--revs", arg)) {
2141                         use_internal_rev_list = 1;
2142                         continue;
2143                 }
2144                 if (!strcmp("--keep-unreachable", arg)) {
2145                         keep_unreachable = 1;
2146                         continue;
2147                 }
2148                 if (!strcmp("--unpack-unreachable", arg)) {
2149                         unpack_unreachable = 1;
2150                         continue;
2151                 }
2152                 if (!strcmp("--include-tag", arg)) {
2153                         include_tag = 1;
2154                         continue;
2155                 }
2156                 if (!strcmp("--unpacked", arg) ||
2157                     !prefixcmp(arg, "--unpacked=") ||
2158                     !strcmp("--reflog", arg) ||
2159                     !strcmp("--all", arg)) {
2160                         use_internal_rev_list = 1;
2161                         if (rp_ac >= rp_ac_alloc - 1) {
2162                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2163                                 rp_av = xrealloc(rp_av,
2164                                                  rp_ac_alloc * sizeof(*rp_av));
2165                         }
2166                         rp_av[rp_ac++] = arg;
2167                         continue;
2168                 }
2169                 if (!strcmp("--thin", arg)) {
2170                         use_internal_rev_list = 1;
2171                         thin = 1;
2172                         rp_av[1] = "--objects-edge";
2173                         continue;
2174                 }
2175                 if (!prefixcmp(arg, "--index-version=")) {
2176                         char *c;
2177                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2178                         if (pack_idx_default_version > 2)
2179                                 die("bad %s", arg);
2180                         if (*c == ',')
2181                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2182                         if (*c || pack_idx_off32_limit & 0x80000000)
2183                                 die("bad %s", arg);
2184                         continue;
2185                 }
2186                 usage(pack_usage);
2187         }
2188
2189         /* Traditionally "pack-objects [options] base extra" failed;
2190          * we would however want to take refs parameter that would
2191          * have been given to upstream rev-list ourselves, which means
2192          * we somehow want to say what the base name is.  So the
2193          * syntax would be:
2194          *
2195          * pack-objects [options] base <refs...>
2196          *
2197          * in other words, we would treat the first non-option as the
2198          * base_name and send everything else to the internal revision
2199          * walker.
2200          */
2201
2202         if (!pack_to_stdout)
2203                 base_name = argv[i++];
2204
2205         if (pack_to_stdout != !base_name)
2206                 usage(pack_usage);
2207
2208         if (!pack_to_stdout && !pack_size_limit)
2209                 pack_size_limit = pack_size_limit_cfg;
2210
2211         if (pack_to_stdout && pack_size_limit)
2212                 die("--max-pack-size cannot be used to build a pack for transfer.");
2213
2214         if (!pack_to_stdout && thin)
2215                 die("--thin cannot be used to build an indexable pack.");
2216
2217         if (keep_unreachable && unpack_unreachable)
2218                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2219
2220 #ifdef THREADED_DELTA_SEARCH
2221         if (!delta_search_threads)      /* --threads=0 means autodetect */
2222                 delta_search_threads = online_cpus();
2223 #endif
2224
2225         prepare_packed_git();
2226
2227         if (progress)
2228                 progress_state = start_progress("Counting objects", 0);
2229         if (!use_internal_rev_list)
2230                 read_object_list_from_stdin();
2231         else {
2232                 rp_av[rp_ac] = NULL;
2233                 get_object_list(rp_ac, rp_av);
2234         }
2235         if (include_tag && nr_result)
2236                 for_each_ref(add_ref_tag, NULL);
2237         stop_progress(&progress_state);
2238
2239         if (non_empty && !nr_result)
2240                 return 0;
2241         if (nr_result)
2242                 prepare_pack(window, depth);
2243         write_pack_file();
2244         if (progress)
2245                 fprintf(stderr, "Total %u (delta %u), reused %u (delta %u)\n",
2246                         written, written_delta, reused, reused_delta);
2247         return 0;
2248 }