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) {
 518                         sha1close(f, sha1, CSUM_CLOSE);
 519                 } else if (nr_written == nr_remaining) {
 520                         sha1close(f, sha1, CSUM_FSYNC);
 521                 } else {
 522                         int fd = sha1close(f, NULL, 0);
 523                         fixup_pack_header_footer(fd, sha1, pack_tmp_name, nr_written);
 524                         fsync_or_die(fd, pack_tmp_name);
 525                         close(fd);
 526                 }
 527
 528                 if (!pack_to_stdout) {
 529                         mode_t mode = umask(0);
 530                         struct stat st;
 531                         char *idx_tmp_name, tmpname[PATH_MAX];
 532
 533                         umask(mode);
 534                         mode = 0444 & ~mode;
 535
 536                         idx_tmp_name = write_idx_file(NULL, written_list,
 537                                                       nr_written, sha1);
 538
 539                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 540                                  base_name, sha1_to_hex(sha1));
 541                         if (adjust_perm(pack_tmp_name, mode))
 542                                 die("unable to make temporary pack file readable: %s",
 543                                     strerror(errno));
 544                         if (rename(pack_tmp_name, tmpname))
 545                                 die("unable to rename temporary pack file: %s",
 546                                     strerror(errno));
 547
 548                         /*
 549                          * Packs are runtime accessed in their mtime
 550                          * order since newer packs are more likely to contain
 551                          * younger objects.  So if we are creating multiple
 552                          * packs then we should modify the mtime of later ones
 553                          * to preserve this property.
 554                          */
 555                         if (stat(tmpname, &st) < 0) {
 556                                 warning("failed to stat %s: %s",
 557                                         tmpname, strerror(errno));
 558                         } else if (!last_mtime) {
 559                                 last_mtime = st.st_mtime;
 560                         } else {
 561                                 struct utimbuf utb;
 562                                 utb.actime = st.st_atime;
 563                                 utb.modtime = --last_mtime;
 564                                 if (utime(tmpname, &utb) < 0)
 565                                         warning("failed utime() on %s: %s",
 566                                                 tmpname, strerror(errno));
 567                         }
 568
 569                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 570                                  base_name, sha1_to_hex(sha1));
 571                         if (adjust_perm(idx_tmp_name, mode))
 572                                 die("unable to make temporary index file readable: %s",
 573                                     strerror(errno));
 574                         if (rename(idx_tmp_name, tmpname))
 575                                 die("unable to rename temporary index file: %s",
 576                                     strerror(errno));
 577
 578                         free(idx_tmp_name);
 579                         free(pack_tmp_name);
 580                         puts(sha1_to_hex(sha1));
 581                 }
 582
 583                 /* mark written objects as written to previous pack */
 584                 for (j = 0; j < nr_written; j++) {
 585                         written_list[j]->offset = (off_t)-1;
 586                 }
 587                 nr_remaining -= nr_written;
 588         } while (nr_remaining && i < nr_objects);
 589
 590         free(written_list);
 591         stop_progress(&progress_state);
 592         if (written != nr_result)
 593                 die("wrote %u objects while expecting %u", written, nr_result);
 594         /*
 595          * We have scanned through [0 ... i).  Since we have written
 596          * the correct number of objects,  the remaining [i ... nr_objects)
 597          * items must be either already written (due to out-of-order delta base)
 598          * or a preferred base.  Count those which are neither and complain if any.
 599          */
 600         for (j = 0; i < nr_objects; i++) {
 601                 struct object_entry *e = objects + i;
 602                 j += !e->idx.offset && !e->preferred_base;
 603         }
 604         if (j)
 605                 die("wrote %u objects as expected but %u unwritten", written, j);
 606 }
 607
 608 static int locate_object_entry_hash(const unsigned char *sha1)
 609 {
 610         int i;
 611         unsigned int ui;
 612         memcpy(&ui, sha1, sizeof(unsigned int));
 613         i = ui % object_ix_hashsz;
 614         while (0 < object_ix[i]) {
 615                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 616                         return i;
 617                 if (++i == object_ix_hashsz)
 618                         i = 0;
 619         }
 620         return -1 - i;
 621 }
 622
 623 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 624 {
 625         int i;
 626
 627         if (!object_ix_hashsz)
 628                 return NULL;
 629
 630         i = locate_object_entry_hash(sha1);
 631         if (0 <= i)
 632                 return &objects[object_ix[i]-1];
 633         return NULL;
 634 }
 635
 636 static void rehash_objects(void)
 637 {
 638         uint32_t i;
 639         struct object_entry *oe;
 640
 641         object_ix_hashsz = nr_objects * 3;
 642         if (object_ix_hashsz < 1024)
 643                 object_ix_hashsz = 1024;
 644         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 645         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 646         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 647                 int ix = locate_object_entry_hash(oe->idx.sha1);
 648                 if (0 <= ix)
 649                         continue;
 650                 ix = -1 - ix;
 651                 object_ix[ix] = i + 1;
 652         }
 653 }
 654
 655 static unsigned name_hash(const char *name)
 656 {
 657         unsigned char c;
 658         unsigned hash = 0;
 659
 660         if (!name)
 661                 return 0;
 662
 663         /*
 664          * This effectively just creates a sortable number from the
 665          * last sixteen non-whitespace characters. Last characters
 666          * count "most", so things that end in ".c" sort together.
 667          */
 668         while ((c = *name++) != 0) {
 669                 if (isspace(c))
 670                         continue;
 671                 hash = (hash >> 2) + (c << 24);
 672         }
 673         return hash;
 674 }
 675
 676 static void setup_delta_attr_check(struct git_attr_check *check)
 677 {
 678         static struct git_attr *attr_delta;
 679
 680         if (!attr_delta)
 681                 attr_delta = git_attr("delta", 5);
 682
 683         check[0].attr = attr_delta;
 684 }
 685
 686 static int no_try_delta(const char *path)
 687 {
 688         struct git_attr_check check[1];
 689
 690         setup_delta_attr_check(check);
 691         if (git_checkattr(path, ARRAY_SIZE(check), check))
 692                 return 0;
 693         if (ATTR_FALSE(check->value))
 694                 return 1;
 695         return 0;
 696 }
 697
 698 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 699                             const char *name, int exclude)
 700 {
 701         struct object_entry *entry;
 702         struct packed_git *p, *found_pack = NULL;
 703         off_t found_offset = 0;
 704         int ix;
 705         unsigned hash = name_hash(name);
 706
 707         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 708         if (ix >= 0) {
 709                 if (exclude) {
 710                         entry = objects + object_ix[ix] - 1;
 711                         if (!entry->preferred_base)
 712                                 nr_result--;
 713                         entry->preferred_base = 1;
 714                 }
 715                 return 0;
 716         }
 717
 718         for (p = packed_git; p; p = p->next) {
 719                 off_t offset = find_pack_entry_one(sha1, p);
 720                 if (offset) {
 721                         if (!found_pack) {
 722                                 found_offset = offset;
 723                                 found_pack = p;
 724                         }
 725                         if (exclude)
 726                                 break;
 727                         if (incremental)
 728                                 return 0;
 729                         if (local && !p->pack_local)
 730                                 return 0;
 731                 }
 732         }
 733
 734         if (nr_objects >= nr_alloc) {
 735                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 736                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 737         }
 738
 739         entry = objects + nr_objects++;
 740         memset(entry, 0, sizeof(*entry));
 741         hashcpy(entry->idx.sha1, sha1);
 742         entry->hash = hash;
 743         if (type)
 744                 entry->type = type;
 745         if (exclude)
 746                 entry->preferred_base = 1;
 747         else
 748                 nr_result++;
 749         if (found_pack) {
 750                 entry->in_pack = found_pack;
 751                 entry->in_pack_offset = found_offset;
 752         }
 753
 754         if (object_ix_hashsz * 3 <= nr_objects * 4)
 755                 rehash_objects();
 756         else
 757                 object_ix[-1 - ix] = nr_objects;
 758
 759         display_progress(progress_state, nr_objects);
 760
 761         if (name && no_try_delta(name))
 762                 entry->no_try_delta = 1;
 763
 764         return 1;
 765 }
 766
 767 struct pbase_tree_cache {
 768         unsigned char sha1[20];
 769         int ref;
 770         int temporary;
 771         void *tree_data;
 772         unsigned long tree_size;
 773 };
 774
 775 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 776 static int pbase_tree_cache_ix(const unsigned char *sha1)
 777 {
 778         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 779 }
 780 static int pbase_tree_cache_ix_incr(int ix)
 781 {
 782         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 783 }
 784
 785 static struct pbase_tree {
 786         struct pbase_tree *next;
 787         /* This is a phony "cache" entry; we are not
 788          * going to evict it nor find it through _get()
 789          * mechanism -- this is for the toplevel node that
 790          * would almost always change with any commit.
 791          */
 792         struct pbase_tree_cache pcache;
 793 } *pbase_tree;
 794
 795 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 796 {
 797         struct pbase_tree_cache *ent, *nent;
 798         void *data;
 799         unsigned long size;
 800         enum object_type type;
 801         int neigh;
 802         int my_ix = pbase_tree_cache_ix(sha1);
 803         int available_ix = -1;
 804
 805         /* pbase-tree-cache acts as a limited hashtable.
 806          * your object will be found at your index or within a few
 807          * slots after that slot if it is cached.
 808          */
 809         for (neigh = 0; neigh < 8; neigh++) {
 810                 ent = pbase_tree_cache[my_ix];
 811                 if (ent && !hashcmp(ent->sha1, sha1)) {
 812                         ent->ref++;
 813                         return ent;
 814                 }
 815                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 816                          ((0 <= available_ix) &&
 817                           (!ent && pbase_tree_cache[available_ix])))
 818                         available_ix = my_ix;
 819                 if (!ent)
 820                         break;
 821                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 822         }
 823
 824         /* Did not find one.  Either we got a bogus request or
 825          * we need to read and perhaps cache.
 826          */
 827         data = read_sha1_file(sha1, &type, &size);
 828         if (!data)
 829                 return NULL;
 830         if (type != OBJ_TREE) {
 831                 free(data);
 832                 return NULL;
 833         }
 834
 835         /* We need to either cache or return a throwaway copy */
 836
 837         if (available_ix < 0)
 838                 ent = NULL;
 839         else {
 840                 ent = pbase_tree_cache[available_ix];
 841                 my_ix = available_ix;
 842         }
 843
 844         if (!ent) {
 845                 nent = xmalloc(sizeof(*nent));
 846                 nent->temporary = (available_ix < 0);
 847         }
 848         else {
 849                 /* evict and reuse */
 850                 free(ent->tree_data);
 851                 nent = ent;
 852         }
 853         hashcpy(nent->sha1, sha1);
 854         nent->tree_data = data;
 855         nent->tree_size = size;
 856         nent->ref = 1;
 857         if (!nent->temporary)
 858                 pbase_tree_cache[my_ix] = nent;
 859         return nent;
 860 }
 861
 862 static void pbase_tree_put(struct pbase_tree_cache *cache)
 863 {
 864         if (!cache->temporary) {
 865                 cache->ref--;
 866                 return;
 867         }
 868         free(cache->tree_data);
 869         free(cache);
 870 }
 871
 872 static int name_cmp_len(const char *name)
 873 {
 874         int i;
 875         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 876                 ;
 877         return i;
 878 }
 879
 880 static void add_pbase_object(struct tree_desc *tree,
 881                              const char *name,
 882                              int cmplen,
 883                              const char *fullname)
 884 {
 885         struct name_entry entry;
 886         int cmp;
 887
 888         while (tree_entry(tree,&entry)) {
 889                 if (S_ISGITLINK(entry.mode))
 890                         continue;
 891                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 892                       memcmp(name, entry.path, cmplen);
 893                 if (cmp > 0)
 894                         continue;
 895                 if (cmp < 0)
 896                         return;
 897                 if (name[cmplen] != '/') {
 898                         add_object_entry(entry.sha1,
 899                                          object_type(entry.mode),
 900                                          fullname, 1);
 901                         return;
 902                 }
 903                 if (S_ISDIR(entry.mode)) {
 904                         struct tree_desc sub;
 905                         struct pbase_tree_cache *tree;
 906                         const char *down = name+cmplen+1;
 907                         int downlen = name_cmp_len(down);
 908
 909                         tree = pbase_tree_get(entry.sha1);
 910                         if (!tree)
 911                                 return;
 912                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 913
 914                         add_pbase_object(&sub, down, downlen, fullname);
 915                         pbase_tree_put(tree);
 916                 }
 917         }
 918 }
 919
 920 static unsigned *done_pbase_paths;
 921 static int done_pbase_paths_num;
 922 static int done_pbase_paths_alloc;
 923 static int done_pbase_path_pos(unsigned hash)
 924 {
 925         int lo = 0;
 926         int hi = done_pbase_paths_num;
 927         while (lo < hi) {
 928                 int mi = (hi + lo) / 2;
 929                 if (done_pbase_paths[mi] == hash)
 930                         return mi;
 931                 if (done_pbase_paths[mi] < hash)
 932                         hi = mi;
 933                 else
 934                         lo = mi + 1;
 935         }
 936         return -lo-1;
 937 }
 938
 939 static int check_pbase_path(unsigned hash)
 940 {
 941         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 942         if (0 <= pos)
 943                 return 1;
 944         pos = -pos - 1;
 945         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 946                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 947                 done_pbase_paths = xrealloc(done_pbase_paths,
 948                                             done_pbase_paths_alloc *
 949                                             sizeof(unsigned));
 950         }
 951         done_pbase_paths_num++;
 952         if (pos < done_pbase_paths_num)
 953                 memmove(done_pbase_paths + pos + 1,
 954                         done_pbase_paths + pos,
 955                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 956         done_pbase_paths[pos] = hash;
 957         return 0;
 958 }
 959
 960 static void add_preferred_base_object(const char *name)
 961 {
 962         struct pbase_tree *it;
 963         int cmplen;
 964         unsigned hash = name_hash(name);
 965
 966         if (!num_preferred_base || check_pbase_path(hash))
 967                 return;
 968
 969         cmplen = name_cmp_len(name);
 970         for (it = pbase_tree; it; it = it->next) {
 971                 if (cmplen == 0) {
 972                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 973                 }
 974                 else {
 975                         struct tree_desc tree;
 976                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 977                         add_pbase_object(&tree, name, cmplen, name);
 978                 }
 979         }
 980 }
 981
 982 static void add_preferred_base(unsigned char *sha1)
 983 {
 984         struct pbase_tree *it;
 985         void *data;
 986         unsigned long size;
 987         unsigned char tree_sha1[20];
 988
 989         if (window <= num_preferred_base++)
 990                 return;
 991
 992         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 993         if (!data)
 994                 return;
 995
 996         for (it = pbase_tree; it; it = it->next) {
 997                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 998                         free(data);
 999                         return;
1000                 }
1001         }
1002
1003         it = xcalloc(1, sizeof(*it));
1004         it->next = pbase_tree;
1005         pbase_tree = it;
1006
1007         hashcpy(it->pcache.sha1, tree_sha1);
1008         it->pcache.tree_data = data;
1009         it->pcache.tree_size = size;
1010 }
1011
1012 static void check_object(struct object_entry *entry)
1013 {
1014         if (entry->in_pack) {
1015                 struct packed_git *p = entry->in_pack;
1016                 struct pack_window *w_curs = NULL;
1017                 const unsigned char *base_ref = NULL;
1018                 struct object_entry *base_entry;
1019                 unsigned long used, used_0;
1020                 unsigned int avail;
1021                 off_t ofs;
1022                 unsigned char *buf, c;
1023
1024                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1025
1026                 /*
1027                  * We want in_pack_type even if we do not reuse delta
1028                  * since non-delta representations could still be reused.
1029                  */
1030                 used = unpack_object_header_gently(buf, avail,
1031                                                    &entry->in_pack_type,
1032                                                    &entry->size);
1033
1034                 /*
1035                  * Determine if this is a delta and if so whether we can
1036                  * reuse it or not.  Otherwise let's find out as cheaply as
1037                  * possible what the actual type and size for this object is.
1038                  */
1039                 switch (entry->in_pack_type) {
1040                 default:
1041                         /* Not a delta hence we've already got all we need. */
1042                         entry->type = entry->in_pack_type;
1043                         entry->in_pack_header_size = used;
1044                         unuse_pack(&w_curs);
1045                         return;
1046                 case OBJ_REF_DELTA:
1047                         if (reuse_delta && !entry->preferred_base)
1048                                 base_ref = use_pack(p, &w_curs,
1049                                                 entry->in_pack_offset + used, NULL);
1050                         entry->in_pack_header_size = used + 20;
1051                         break;
1052                 case OBJ_OFS_DELTA:
1053                         buf = use_pack(p, &w_curs,
1054                                        entry->in_pack_offset + used, NULL);
1055                         used_0 = 0;
1056                         c = buf[used_0++];
1057                         ofs = c & 127;
1058                         while (c & 128) {
1059                                 ofs += 1;
1060                                 if (!ofs || MSB(ofs, 7))
1061                                         die("delta base offset overflow in pack for %s",
1062                                             sha1_to_hex(entry->idx.sha1));
1063                                 c = buf[used_0++];
1064                                 ofs = (ofs << 7) + (c & 127);
1065                         }
1066                         if (ofs >= entry->in_pack_offset)
1067                                 die("delta base offset out of bound for %s",
1068                                     sha1_to_hex(entry->idx.sha1));
1069                         ofs = entry->in_pack_offset - ofs;
1070                         if (reuse_delta && !entry->preferred_base) {
1071                                 struct revindex_entry *revidx;
1072                                 revidx = find_pack_revindex(p, ofs);
1073                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1074                         }
1075                         entry->in_pack_header_size = used + used_0;
1076                         break;
1077                 }
1078
1079                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1080                         /*
1081                          * If base_ref was set above that means we wish to
1082                          * reuse delta data, and we even found that base
1083                          * in the list of objects we want to pack. Goodie!
1084                          *
1085                          * Depth value does not matter - find_deltas() will
1086                          * never consider reused delta as the base object to
1087                          * deltify other objects against, in order to avoid
1088                          * circular deltas.
1089                          */
1090                         entry->type = entry->in_pack_type;
1091                         entry->delta = base_entry;
1092                         entry->delta_sibling = base_entry->delta_child;
1093                         base_entry->delta_child = entry;
1094                         unuse_pack(&w_curs);
1095                         return;
1096                 }
1097
1098                 if (entry->type) {
1099                         /*
1100                          * This must be a delta and we already know what the
1101                          * final object type is.  Let's extract the actual
1102                          * object size from the delta header.
1103                          */
1104                         entry->size = get_size_from_delta(p, &w_curs,
1105                                         entry->in_pack_offset + entry->in_pack_header_size);
1106                         unuse_pack(&w_curs);
1107                         return;
1108                 }
1109
1110                 /*
1111                  * No choice but to fall back to the recursive delta walk
1112                  * with sha1_object_info() to find about the object type
1113                  * at this point...
1114                  */
1115                 unuse_pack(&w_curs);
1116         }
1117
1118         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1119         if (entry->type < 0)
1120                 die("unable to get type of object %s",
1121                     sha1_to_hex(entry->idx.sha1));
1122 }
1123
1124 static int pack_offset_sort(const void *_a, const void *_b)
1125 {
1126         const struct object_entry *a = *(struct object_entry **)_a;
1127         const struct object_entry *b = *(struct object_entry **)_b;
1128
1129         /* avoid filesystem trashing with loose objects */
1130         if (!a->in_pack && !b->in_pack)
1131                 return hashcmp(a->idx.sha1, b->idx.sha1);
1132
1133         if (a->in_pack < b->in_pack)
1134                 return -1;
1135         if (a->in_pack > b->in_pack)
1136                 return 1;
1137         return a->in_pack_offset < b->in_pack_offset ? -1 :
1138                         (a->in_pack_offset > b->in_pack_offset);
1139 }
1140
1141 static void get_object_details(void)
1142 {
1143         uint32_t i;
1144         struct object_entry **sorted_by_offset;
1145
1146         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1147         for (i = 0; i < nr_objects; i++)
1148                 sorted_by_offset[i] = objects + i;
1149         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1150
1151         init_pack_revindex();
1152
1153         for (i = 0; i < nr_objects; i++)
1154                 check_object(sorted_by_offset[i]);
1155
1156         free(sorted_by_offset);
1157 }
1158
1159 /*
1160  * We search for deltas in a list sorted by type, by filename hash, and then
1161  * by size, so that we see progressively smaller and smaller files.
1162  * That's because we prefer deltas to be from the bigger file
1163  * to the smaller -- deletes are potentially cheaper, but perhaps
1164  * more importantly, the bigger file is likely the more recent
1165  * one.  The deepest deltas are therefore the oldest objects which are
1166  * less susceptible to be accessed often.
1167  */
1168 static int type_size_sort(const void *_a, const void *_b)
1169 {
1170         const struct object_entry *a = *(struct object_entry **)_a;
1171         const struct object_entry *b = *(struct object_entry **)_b;
1172
1173         if (a->type > b->type)
1174                 return -1;
1175         if (a->type < b->type)
1176                 return 1;
1177         if (a->hash > b->hash)
1178                 return -1;
1179         if (a->hash < b->hash)
1180                 return 1;
1181         if (a->preferred_base > b->preferred_base)
1182                 return -1;
1183         if (a->preferred_base < b->preferred_base)
1184                 return 1;
1185         if (a->size > b->size)
1186                 return -1;
1187         if (a->size < b->size)
1188                 return 1;
1189         return a < b ? -1 : (a > b);  /* newest first */
1190 }
1191
1192 struct unpacked {
1193         struct object_entry *entry;
1194         void *data;
1195         struct delta_index *index;
1196         unsigned depth;
1197 };
1198
1199 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1200                            unsigned long delta_size)
1201 {
1202         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1203                 return 0;
1204
1205         if (delta_size < cache_max_small_delta_size)
1206                 return 1;
1207
1208         /* cache delta, if objects are large enough compared to delta size */
1209         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1210                 return 1;
1211
1212         return 0;
1213 }
1214
1215 #ifdef THREADED_DELTA_SEARCH
1216
1217 static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1218 #define read_lock()             pthread_mutex_lock(&read_mutex)
1219 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1220
1221 static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1222 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1223 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1224
1225 static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1226 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1227 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1228
1229 #else
1230
1231 #define read_lock()             (void)0
1232 #define read_unlock()           (void)0
1233 #define cache_lock()            (void)0
1234 #define cache_unlock()          (void)0
1235 #define progress_lock()         (void)0
1236 #define progress_unlock()       (void)0
1237
1238 #endif
1239
1240 static int try_delta(struct unpacked *trg, struct unpacked *src,
1241                      unsigned max_depth, unsigned long *mem_usage)
1242 {
1243         struct object_entry *trg_entry = trg->entry;
1244         struct object_entry *src_entry = src->entry;
1245         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1246         unsigned ref_depth;
1247         enum object_type type;
1248         void *delta_buf;
1249
1250         /* Don't bother doing diffs between different types */
1251         if (trg_entry->type != src_entry->type)
1252                 return -1;
1253
1254         /*
1255          * We do not bother to try a delta that we discarded
1256          * on an earlier try, but only when reusing delta data.
1257          */
1258         if (reuse_delta && trg_entry->in_pack &&
1259             trg_entry->in_pack == src_entry->in_pack &&
1260             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1261             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1262                 return 0;
1263
1264         /* Let's not bust the allowed depth. */
1265         if (src->depth >= max_depth)
1266                 return 0;
1267
1268         /* Now some size filtering heuristics. */
1269         trg_size = trg_entry->size;
1270         if (!trg_entry->delta) {
1271                 max_size = trg_size/2 - 20;
1272                 ref_depth = 1;
1273         } else {
1274                 max_size = trg_entry->delta_size;
1275                 ref_depth = trg->depth;
1276         }
1277         max_size = max_size * (max_depth - src->depth) /
1278                                                 (max_depth - ref_depth + 1);
1279         if (max_size == 0)
1280                 return 0;
1281         src_size = src_entry->size;
1282         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1283         if (sizediff >= max_size)
1284                 return 0;
1285         if (trg_size < src_size / 32)
1286                 return 0;
1287
1288         /* Load data if not already done */
1289         if (!trg->data) {
1290                 read_lock();
1291                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1292                 read_unlock();
1293                 if (!trg->data)
1294                         die("object %s cannot be read",
1295                             sha1_to_hex(trg_entry->idx.sha1));
1296                 if (sz != trg_size)
1297                         die("object %s inconsistent object length (%lu vs %lu)",
1298                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1299                 *mem_usage += sz;
1300         }
1301         if (!src->data) {
1302                 read_lock();
1303                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1304                 read_unlock();
1305                 if (!src->data)
1306                         die("object %s cannot be read",
1307                             sha1_to_hex(src_entry->idx.sha1));
1308                 if (sz != src_size)
1309                         die("object %s inconsistent object length (%lu vs %lu)",
1310                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1311                 *mem_usage += sz;
1312         }
1313         if (!src->index) {
1314                 src->index = create_delta_index(src->data, src_size);
1315                 if (!src->index) {
1316                         static int warned = 0;
1317                         if (!warned++)
1318                                 warning("suboptimal pack - out of memory");
1319                         return 0;
1320                 }
1321                 *mem_usage += sizeof_delta_index(src->index);
1322         }
1323
1324         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1325         if (!delta_buf)
1326                 return 0;
1327
1328         if (trg_entry->delta) {
1329                 /* Prefer only shallower same-sized deltas. */
1330                 if (delta_size == trg_entry->delta_size &&
1331                     src->depth + 1 >= trg->depth) {
1332                         free(delta_buf);
1333                         return 0;
1334                 }
1335         }
1336
1337         /*
1338          * Handle memory allocation outside of the cache
1339          * accounting lock.  Compiler will optimize the strangeness
1340          * away when THREADED_DELTA_SEARCH is not defined.
1341          */
1342         free(trg_entry->delta_data);
1343         cache_lock();
1344         if (trg_entry->delta_data) {
1345                 delta_cache_size -= trg_entry->delta_size;
1346                 trg_entry->delta_data = NULL;
1347         }
1348         if (delta_cacheable(src_size, trg_size, delta_size)) {
1349                 delta_cache_size += delta_size;
1350                 cache_unlock();
1351                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1352         } else {
1353                 cache_unlock();
1354                 free(delta_buf);
1355         }
1356
1357         trg_entry->delta = src_entry;
1358         trg_entry->delta_size = delta_size;
1359         trg->depth = src->depth + 1;
1360
1361         return 1;
1362 }
1363
1364 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1365 {
1366         struct object_entry *child = me->delta_child;
1367         unsigned int m = n;
1368         while (child) {
1369                 unsigned int c = check_delta_limit(child, n + 1);
1370                 if (m < c)
1371                         m = c;
1372                 child = child->delta_sibling;
1373         }
1374         return m;
1375 }
1376
1377 static unsigned long free_unpacked(struct unpacked *n)
1378 {
1379         unsigned long freed_mem = sizeof_delta_index(n->index);
1380         free_delta_index(n->index);
1381         n->index = NULL;
1382         if (n->data) {
1383                 freed_mem += n->entry->size;
1384                 free(n->data);
1385                 n->data = NULL;
1386         }
1387         n->entry = NULL;
1388         n->depth = 0;
1389         return freed_mem;
1390 }
1391
1392 static void find_deltas(struct object_entry **list, unsigned *list_size,
1393                         int window, int depth, unsigned *processed)
1394 {
1395         uint32_t i, idx = 0, count = 0;
1396         unsigned int array_size = window * sizeof(struct unpacked);
1397         struct unpacked *array;
1398         unsigned long mem_usage = 0;
1399
1400         array = xmalloc(array_size);
1401         memset(array, 0, array_size);
1402
1403         for (;;) {
1404                 struct object_entry *entry = *list++;
1405                 struct unpacked *n = array + idx;
1406                 int j, max_depth, best_base = -1;
1407
1408                 progress_lock();
1409                 if (!*list_size) {
1410                         progress_unlock();
1411                         break;
1412                 }
1413                 (*list_size)--;
1414                 if (!entry->preferred_base) {
1415                         (*processed)++;
1416                         display_progress(progress_state, *processed);
1417                 }
1418                 progress_unlock();
1419
1420                 mem_usage -= free_unpacked(n);
1421                 n->entry = entry;
1422
1423                 while (window_memory_limit &&
1424                        mem_usage > window_memory_limit &&
1425                        count > 1) {
1426                         uint32_t tail = (idx + window - count) % window;
1427                         mem_usage -= free_unpacked(array + tail);
1428                         count--;
1429                 }
1430
1431                 /* We do not compute delta to *create* objects we are not
1432                  * going to pack.
1433                  */
1434                 if (entry->preferred_base)
1435                         goto next;
1436
1437                 /*
1438                  * If the current object is at pack edge, take the depth the
1439                  * objects that depend on the current object into account
1440                  * otherwise they would become too deep.
1441                  */
1442                 max_depth = depth;
1443                 if (entry->delta_child) {
1444                         max_depth -= check_delta_limit(entry, 0);
1445                         if (max_depth <= 0)
1446                                 goto next;
1447                 }
1448
1449                 j = window;
1450                 while (--j > 0) {
1451                         int ret;
1452                         uint32_t other_idx = idx + j;
1453                         struct unpacked *m;
1454                         if (other_idx >= window)
1455                                 other_idx -= window;
1456                         m = array + other_idx;
1457                         if (!m->entry)
1458                                 break;
1459                         ret = try_delta(n, m, max_depth, &mem_usage);
1460                         if (ret < 0)
1461                                 break;
1462                         else if (ret > 0)
1463                                 best_base = other_idx;
1464                 }
1465
1466                 /*
1467                  * If we decided to cache the delta data, then it is best
1468                  * to compress it right away.  First because we have to do
1469                  * it anyway, and doing it here while we're threaded will
1470                  * save a lot of time in the non threaded write phase,
1471                  * as well as allow for caching more deltas within
1472                  * the same cache size limit.
1473                  * ...
1474                  * But only if not writing to stdout, since in that case
1475                  * the network is most likely throttling writes anyway,
1476                  * and therefore it is best to go to the write phase ASAP
1477                  * instead, as we can afford spending more time compressing
1478                  * between writes at that moment.
1479                  */
1480                 if (entry->delta_data && !pack_to_stdout) {
1481                         entry->z_delta_size = do_compress(&entry->delta_data,
1482                                                           entry->delta_size);
1483                         cache_lock();
1484                         delta_cache_size -= entry->delta_size;
1485                         delta_cache_size += entry->z_delta_size;
1486                         cache_unlock();
1487                 }
1488
1489                 /* if we made n a delta, and if n is already at max
1490                  * depth, leaving it in the window is pointless.  we
1491                  * should evict it first.
1492                  */
1493                 if (entry->delta && max_depth <= n->depth)
1494                         continue;
1495
1496                 /*
1497                  * Move the best delta base up in the window, after the
1498                  * currently deltified object, to keep it longer.  It will
1499                  * be the first base object to be attempted next.
1500                  */
1501                 if (entry->delta) {
1502                         struct unpacked swap = array[best_base];
1503                         int dist = (window + idx - best_base) % window;
1504                         int dst = best_base;
1505                         while (dist--) {
1506                                 int src = (dst + 1) % window;
1507                                 array[dst] = array[src];
1508                                 dst = src;
1509                         }
1510                         array[dst] = swap;
1511                 }
1512
1513                 next:
1514                 idx++;
1515                 if (count + 1 < window)
1516                         count++;
1517                 if (idx >= window)
1518                         idx = 0;
1519         }
1520
1521         for (i = 0; i < window; ++i) {
1522                 free_delta_index(array[i].index);
1523                 free(array[i].data);
1524         }
1525         free(array);
1526 }
1527
1528 #ifdef THREADED_DELTA_SEARCH
1529
1530 /*
1531  * The main thread waits on the condition that (at least) one of the workers
1532  * has stopped working (which is indicated in the .working member of
1533  * struct thread_params).
1534  * When a work thread has completed its work, it sets .working to 0 and
1535  * signals the main thread and waits on the condition that .data_ready
1536  * becomes 1.
1537  */
1538
1539 struct thread_params {
1540         pthread_t thread;
1541         struct object_entry **list;
1542         unsigned list_size;
1543         unsigned remaining;
1544         int window;
1545         int depth;
1546         int working;
1547         int data_ready;
1548         pthread_mutex_t mutex;
1549         pthread_cond_t cond;
1550         unsigned *processed;
1551 };
1552
1553 static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
1554
1555 static void *threaded_find_deltas(void *arg)
1556 {
1557         struct thread_params *me = arg;
1558
1559         while (me->remaining) {
1560                 find_deltas(me->list, &me->remaining,
1561                             me->window, me->depth, me->processed);
1562
1563                 progress_lock();
1564                 me->working = 0;
1565                 pthread_cond_signal(&progress_cond);
1566                 progress_unlock();
1567
1568                 /*
1569                  * We must not set ->data_ready before we wait on the
1570                  * condition because the main thread may have set it to 1
1571                  * before we get here. In order to be sure that new
1572                  * work is available if we see 1 in ->data_ready, it
1573                  * was initialized to 0 before this thread was spawned
1574                  * and we reset it to 0 right away.
1575                  */
1576                 pthread_mutex_lock(&me->mutex);
1577                 while (!me->data_ready)
1578                         pthread_cond_wait(&me->cond, &me->mutex);
1579                 me->data_ready = 0;
1580                 pthread_mutex_unlock(&me->mutex);
1581         }
1582         /* leave ->working 1 so that this doesn't get more work assigned */
1583         return NULL;
1584 }
1585
1586 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1587                            int window, int depth, unsigned *processed)
1588 {
1589         struct thread_params p[delta_search_threads];
1590         int i, ret, active_threads = 0;
1591
1592         if (delta_search_threads <= 1) {
1593                 find_deltas(list, &list_size, window, depth, processed);
1594                 return;
1595         }
1596
1597         /* Partition the work amongst work threads. */
1598         for (i = 0; i < delta_search_threads; i++) {
1599                 unsigned sub_size = list_size / (delta_search_threads - i);
1600
1601                 p[i].window = window;
1602                 p[i].depth = depth;
1603                 p[i].processed = processed;
1604                 p[i].working = 1;
1605                 p[i].data_ready = 0;
1606
1607                 /* try to split chunks on "path" boundaries */
1608                 while (sub_size && sub_size < list_size &&
1609                        list[sub_size]->hash &&
1610                        list[sub_size]->hash == list[sub_size-1]->hash)
1611                         sub_size++;
1612
1613                 p[i].list = list;
1614                 p[i].list_size = sub_size;
1615                 p[i].remaining = sub_size;
1616
1617                 list += sub_size;
1618                 list_size -= sub_size;
1619         }
1620
1621         /* Start work threads. */
1622         for (i = 0; i < delta_search_threads; i++) {
1623                 if (!p[i].list_size)
1624                         continue;
1625                 pthread_mutex_init(&p[i].mutex, NULL);
1626                 pthread_cond_init(&p[i].cond, NULL);
1627                 ret = pthread_create(&p[i].thread, NULL,
1628                                      threaded_find_deltas, &p[i]);
1629                 if (ret)
1630                         die("unable to create thread: %s", strerror(ret));
1631                 active_threads++;
1632         }
1633
1634         /*
1635          * Now let's wait for work completion.  Each time a thread is done
1636          * with its work, we steal half of the remaining work from the
1637          * thread with the largest number of unprocessed objects and give
1638          * it to that newly idle thread.  This ensure good load balancing
1639          * until the remaining object list segments are simply too short
1640          * to be worth splitting anymore.
1641          */
1642         while (active_threads) {
1643                 struct thread_params *target = NULL;
1644                 struct thread_params *victim = NULL;
1645                 unsigned sub_size = 0;
1646
1647                 progress_lock();
1648                 for (;;) {
1649                         for (i = 0; !target && i < delta_search_threads; i++)
1650                                 if (!p[i].working)
1651                                         target = &p[i];
1652                         if (target)
1653                                 break;
1654                         pthread_cond_wait(&progress_cond, &progress_mutex);
1655                 }
1656
1657                 for (i = 0; i < delta_search_threads; i++)
1658                         if (p[i].remaining > 2*window &&
1659                             (!victim || victim->remaining < p[i].remaining))
1660                                 victim = &p[i];
1661                 if (victim) {
1662                         sub_size = victim->remaining / 2;
1663                         list = victim->list + victim->list_size - sub_size;
1664                         while (sub_size && list[0]->hash &&
1665                                list[0]->hash == list[-1]->hash) {
1666                                 list++;
1667                                 sub_size--;
1668                         }
1669                         if (!sub_size) {
1670                                 /*
1671                                  * It is possible for some "paths" to have
1672                                  * so many objects that no hash boundary
1673                                  * might be found.  Let's just steal the
1674                                  * exact half in that case.
1675                                  */
1676                                 sub_size = victim->remaining / 2;
1677                                 list -= sub_size;
1678                         }
1679                         target->list = list;
1680                         victim->list_size -= sub_size;
1681                         victim->remaining -= sub_size;
1682                 }
1683                 target->list_size = sub_size;
1684                 target->remaining = sub_size;
1685                 target->working = 1;
1686                 progress_unlock();
1687
1688                 pthread_mutex_lock(&target->mutex);
1689                 target->data_ready = 1;
1690                 pthread_cond_signal(&target->cond);
1691                 pthread_mutex_unlock(&target->mutex);
1692
1693                 if (!sub_size) {
1694                         pthread_join(target->thread, NULL);
1695                         pthread_cond_destroy(&target->cond);
1696                         pthread_mutex_destroy(&target->mutex);
1697                         active_threads--;
1698                 }
1699         }
1700 }
1701
1702 #else
1703 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1704 #endif
1705
1706 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1707 {
1708         unsigned char peeled[20];
1709
1710         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1711             !peel_ref(path, peeled)        && /* peelable? */
1712             !is_null_sha1(peeled)          && /* annotated tag? */
1713             locate_object_entry(peeled))      /* object packed? */
1714                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1715         return 0;
1716 }
1717
1718 static void prepare_pack(int window, int depth)
1719 {
1720         struct object_entry **delta_list;
1721         uint32_t i, n, nr_deltas;
1722
1723         get_object_details();
1724
1725         if (!nr_objects || !window || !depth)
1726                 return;
1727
1728         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1729         nr_deltas = n = 0;
1730
1731         for (i = 0; i < nr_objects; i++) {
1732                 struct object_entry *entry = objects + i;
1733
1734                 if (entry->delta)
1735                         /* This happens if we decided to reuse existing
1736                          * delta from a pack.  "reuse_delta &&" is implied.
1737                          */
1738                         continue;
1739
1740                 if (entry->size < 50)
1741                         continue;
1742
1743                 if (entry->no_try_delta)
1744                         continue;
1745
1746                 if (!entry->preferred_base)
1747                         nr_deltas++;
1748
1749                 delta_list[n++] = entry;
1750         }
1751
1752         if (nr_deltas && n > 1) {
1753                 unsigned nr_done = 0;
1754                 if (progress)
1755                         progress_state = start_progress("Compressing objects",
1756                                                         nr_deltas);
1757                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1758                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1759                 stop_progress(&progress_state);
1760                 if (nr_done != nr_deltas)
1761                         die("inconsistency with delta count");
1762         }
1763         free(delta_list);
1764 }
1765
1766 static int git_pack_config(const char *k, const char *v, void *cb)
1767 {
1768         if(!strcmp(k, "pack.window")) {
1769                 window = git_config_int(k, v);
1770                 return 0;
1771         }
1772         if (!strcmp(k, "pack.windowmemory")) {
1773                 window_memory_limit = git_config_ulong(k, v);
1774                 return 0;
1775         }
1776         if (!strcmp(k, "pack.depth")) {
1777                 depth = git_config_int(k, v);
1778                 return 0;
1779         }
1780         if (!strcmp(k, "pack.compression")) {
1781                 int level = git_config_int(k, v);
1782                 if (level == -1)
1783                         level = Z_DEFAULT_COMPRESSION;
1784                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1785                         die("bad pack compression level %d", level);
1786                 pack_compression_level = level;
1787                 pack_compression_seen = 1;
1788                 return 0;
1789         }
1790         if (!strcmp(k, "pack.deltacachesize")) {
1791                 max_delta_cache_size = git_config_int(k, v);
1792                 return 0;
1793         }
1794         if (!strcmp(k, "pack.deltacachelimit")) {
1795                 cache_max_small_delta_size = git_config_int(k, v);
1796                 return 0;
1797         }
1798         if (!strcmp(k, "pack.threads")) {
1799                 delta_search_threads = git_config_int(k, v);
1800                 if (delta_search_threads < 0)
1801                         die("invalid number of threads specified (%d)",
1802                             delta_search_threads);
1803 #ifndef THREADED_DELTA_SEARCH
1804                 if (delta_search_threads != 1)
1805                         warning("no threads support, ignoring %s", k);
1806 #endif
1807                 return 0;
1808         }
1809         if (!strcmp(k, "pack.indexversion")) {
1810                 pack_idx_default_version = git_config_int(k, v);
1811                 if (pack_idx_default_version > 2)
1812                         die("bad pack.indexversion=%d", pack_idx_default_version);
1813                 return 0;
1814         }
1815         if (!strcmp(k, "pack.packsizelimit")) {
1816                 pack_size_limit_cfg = git_config_ulong(k, v);
1817                 return 0;
1818         }
1819         return git_default_config(k, v, cb);
1820 }
1821
1822 static void read_object_list_from_stdin(void)
1823 {
1824         char line[40 + 1 + PATH_MAX + 2];
1825         unsigned char sha1[20];
1826
1827         for (;;) {
1828                 if (!fgets(line, sizeof(line), stdin)) {
1829                         if (feof(stdin))
1830                                 break;
1831                         if (!ferror(stdin))
1832                                 die("fgets returned NULL, not EOF, not error!");
1833                         if (errno != EINTR)
1834                                 die("fgets: %s", strerror(errno));
1835                         clearerr(stdin);
1836                         continue;
1837                 }
1838                 if (line[0] == '-') {
1839                         if (get_sha1_hex(line+1, sha1))
1840                                 die("expected edge sha1, got garbage:\n %s",
1841                                     line);
1842                         add_preferred_base(sha1);
1843                         continue;
1844                 }
1845                 if (get_sha1_hex(line, sha1))
1846                         die("expected sha1, got garbage:\n %s", line);
1847
1848                 add_preferred_base_object(line+41);
1849                 add_object_entry(sha1, 0, line+41, 0);
1850         }
1851 }
1852
1853 #define OBJECT_ADDED (1u<<20)
1854
1855 static void show_commit(struct commit *commit)
1856 {
1857         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1858         commit->object.flags |= OBJECT_ADDED;
1859 }
1860
1861 static void show_object(struct object_array_entry *p)
1862 {
1863         add_preferred_base_object(p->name);
1864         add_object_entry(p->item->sha1, p->item->type, p->name, 0);
1865         p->item->flags |= OBJECT_ADDED;
1866 }
1867
1868 static void show_edge(struct commit *commit)
1869 {
1870         add_preferred_base(commit->object.sha1);
1871 }
1872
1873 struct in_pack_object {
1874         off_t offset;
1875         struct object *object;
1876 };
1877
1878 struct in_pack {
1879         int alloc;
1880         int nr;
1881         struct in_pack_object *array;
1882 };
1883
1884 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1885 {
1886         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1887         in_pack->array[in_pack->nr].object = object;
1888         in_pack->nr++;
1889 }
1890
1891 /*
1892  * Compare the objects in the offset order, in order to emulate the
1893  * "git-rev-list --objects" output that produced the pack originally.
1894  */
1895 static int ofscmp(const void *a_, const void *b_)
1896 {
1897         struct in_pack_object *a = (struct in_pack_object *)a_;
1898         struct in_pack_object *b = (struct in_pack_object *)b_;
1899
1900         if (a->offset < b->offset)
1901                 return -1;
1902         else if (a->offset > b->offset)
1903                 return 1;
1904         else
1905                 return hashcmp(a->object->sha1, b->object->sha1);
1906 }
1907
1908 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1909 {
1910         struct packed_git *p;
1911         struct in_pack in_pack;
1912         uint32_t i;
1913
1914         memset(&in_pack, 0, sizeof(in_pack));
1915
1916         for (p = packed_git; p; p = p->next) {
1917                 const unsigned char *sha1;
1918                 struct object *o;
1919
1920                 for (i = 0; i < revs->num_ignore_packed; i++) {
1921                         if (matches_pack_name(p, revs->ignore_packed[i]))
1922                                 break;
1923                 }
1924                 if (revs->num_ignore_packed <= i)
1925                         continue;
1926                 if (open_pack_index(p))
1927                         die("cannot open pack index");
1928
1929                 ALLOC_GROW(in_pack.array,
1930                            in_pack.nr + p->num_objects,
1931                            in_pack.alloc);
1932
1933                 for (i = 0; i < p->num_objects; i++) {
1934                         sha1 = nth_packed_object_sha1(p, i);
1935                         o = lookup_unknown_object(sha1);
1936                         if (!(o->flags & OBJECT_ADDED))
1937                                 mark_in_pack_object(o, p, &in_pack);
1938                         o->flags |= OBJECT_ADDED;
1939                 }
1940         }
1941
1942         if (in_pack.nr) {
1943                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
1944                       ofscmp);
1945                 for (i = 0; i < in_pack.nr; i++) {
1946                         struct object *o = in_pack.array[i].object;
1947                         add_object_entry(o->sha1, o->type, "", 0);
1948                 }
1949         }
1950         free(in_pack.array);
1951 }
1952
1953 static void loosen_unused_packed_objects(struct rev_info *revs)
1954 {
1955         struct packed_git *p;
1956         uint32_t i;
1957         const unsigned char *sha1;
1958
1959         for (p = packed_git; p; p = p->next) {
1960                 for (i = 0; i < revs->num_ignore_packed; i++) {
1961                         if (matches_pack_name(p, revs->ignore_packed[i]))
1962                                 break;
1963                 }
1964                 if (revs->num_ignore_packed <= i)
1965                         continue;
1966
1967                 if (open_pack_index(p))
1968                         die("cannot open pack index");
1969
1970                 for (i = 0; i < p->num_objects; i++) {
1971                         sha1 = nth_packed_object_sha1(p, i);
1972                         if (!locate_object_entry(sha1))
1973                                 if (force_object_loose(sha1, p->mtime))
1974                                         die("unable to force loose object");
1975                 }
1976         }
1977 }
1978
1979 static void get_object_list(int ac, const char **av)
1980 {
1981         struct rev_info revs;
1982         char line[1000];
1983         int flags = 0;
1984
1985         init_revisions(&revs, NULL);
1986         save_commit_buffer = 0;
1987         setup_revisions(ac, av, &revs, NULL);
1988
1989         while (fgets(line, sizeof(line), stdin) != NULL) {
1990                 int len = strlen(line);
1991                 if (len && line[len - 1] == '\n')
1992                         line[--len] = 0;
1993                 if (!len)
1994                         break;
1995                 if (*line == '-') {
1996                         if (!strcmp(line, "--not")) {
1997                                 flags ^= UNINTERESTING;
1998                                 continue;
1999                         }
2000                         die("not a rev '%s'", line);
2001                 }
2002                 if (handle_revision_arg(line, &revs, flags, 1))
2003                         die("bad revision '%s'", line);
2004         }
2005
2006         if (prepare_revision_walk(&revs))
2007                 die("revision walk setup failed");
2008         mark_edges_uninteresting(revs.commits, &revs, show_edge);
2009         traverse_commit_list(&revs, show_commit, show_object);
2010
2011         if (keep_unreachable)
2012                 add_objects_in_unpacked_packs(&revs);
2013         if (unpack_unreachable)
2014                 loosen_unused_packed_objects(&revs);
2015 }
2016
2017 static int adjust_perm(const char *path, mode_t mode)
2018 {
2019         if (chmod(path, mode))
2020                 return -1;
2021         return adjust_shared_perm(path);
2022 }
2023
2024 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2025 {
2026         int use_internal_rev_list = 0;
2027         int thin = 0;
2028         uint32_t i;
2029         const char **rp_av;
2030         int rp_ac_alloc = 64;
2031         int rp_ac;
2032
2033         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2034
2035         rp_av[0] = "pack-objects";
2036         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2037         rp_ac = 2;
2038
2039         git_config(git_pack_config, NULL);
2040         if (!pack_compression_seen && core_compression_seen)
2041                 pack_compression_level = core_compression_level;
2042
2043         progress = isatty(2);
2044         for (i = 1; i < argc; i++) {
2045                 const char *arg = argv[i];
2046
2047                 if (*arg != '-')
2048                         break;
2049
2050                 if (!strcmp("--non-empty", arg)) {
2051                         non_empty = 1;
2052                         continue;
2053                 }
2054                 if (!strcmp("--local", arg)) {
2055                         local = 1;
2056                         continue;
2057                 }
2058                 if (!strcmp("--incremental", arg)) {
2059                         incremental = 1;
2060                         continue;
2061                 }
2062                 if (!prefixcmp(arg, "--compression=")) {
2063                         char *end;
2064                         int level = strtoul(arg+14, &end, 0);
2065                         if (!arg[14] || *end)
2066                                 usage(pack_usage);
2067                         if (level == -1)
2068                                 level = Z_DEFAULT_COMPRESSION;
2069                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2070                                 die("bad pack compression level %d", level);
2071                         pack_compression_level = level;
2072                         continue;
2073                 }
2074                 if (!prefixcmp(arg, "--max-pack-size=")) {
2075                         char *end;
2076                         pack_size_limit_cfg = 0;
2077                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2078                         if (!arg[16] || *end)
2079                                 usage(pack_usage);
2080                         continue;
2081                 }
2082                 if (!prefixcmp(arg, "--window=")) {
2083                         char *end;
2084                         window = strtoul(arg+9, &end, 0);
2085                         if (!arg[9] || *end)
2086                                 usage(pack_usage);
2087                         continue;
2088                 }
2089                 if (!prefixcmp(arg, "--window-memory=")) {
2090                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2091                                 usage(pack_usage);
2092                         continue;
2093                 }
2094                 if (!prefixcmp(arg, "--threads=")) {
2095                         char *end;
2096                         delta_search_threads = strtoul(arg+10, &end, 0);
2097                         if (!arg[10] || *end || delta_search_threads < 0)
2098                                 usage(pack_usage);
2099 #ifndef THREADED_DELTA_SEARCH
2100                         if (delta_search_threads != 1)
2101                                 warning("no threads support, "
2102                                         "ignoring %s", arg);
2103 #endif
2104                         continue;
2105                 }
2106                 if (!prefixcmp(arg, "--depth=")) {
2107                         char *end;
2108                         depth = strtoul(arg+8, &end, 0);
2109                         if (!arg[8] || *end)
2110                                 usage(pack_usage);
2111                         continue;
2112                 }
2113                 if (!strcmp("--progress", arg)) {
2114                         progress = 1;
2115                         continue;
2116                 }
2117                 if (!strcmp("--all-progress", arg)) {
2118                         progress = 2;
2119                         continue;
2120                 }
2121                 if (!strcmp("-q", arg)) {
2122                         progress = 0;
2123                         continue;
2124                 }
2125                 if (!strcmp("--no-reuse-delta", arg)) {
2126                         reuse_delta = 0;
2127                         continue;
2128                 }
2129                 if (!strcmp("--no-reuse-object", arg)) {
2130                         reuse_object = reuse_delta = 0;
2131                         continue;
2132                 }
2133                 if (!strcmp("--delta-base-offset", arg)) {
2134                         allow_ofs_delta = 1;
2135                         continue;
2136                 }
2137                 if (!strcmp("--stdout", arg)) {
2138                         pack_to_stdout = 1;
2139                         continue;
2140                 }
2141                 if (!strcmp("--revs", arg)) {
2142                         use_internal_rev_list = 1;
2143                         continue;
2144                 }
2145                 if (!strcmp("--keep-unreachable", arg)) {
2146                         keep_unreachable = 1;
2147                         continue;
2148                 }
2149                 if (!strcmp("--unpack-unreachable", arg)) {
2150                         unpack_unreachable = 1;
2151                         continue;
2152                 }
2153                 if (!strcmp("--include-tag", arg)) {
2154                         include_tag = 1;
2155                         continue;
2156                 }
2157                 if (!strcmp("--unpacked", arg) ||
2158                     !prefixcmp(arg, "--unpacked=") ||
2159                     !strcmp("--reflog", arg) ||
2160                     !strcmp("--all", arg)) {
2161                         use_internal_rev_list = 1;
2162                         if (rp_ac >= rp_ac_alloc - 1) {
2163                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2164                                 rp_av = xrealloc(rp_av,
2165                                                  rp_ac_alloc * sizeof(*rp_av));
2166                         }
2167                         rp_av[rp_ac++] = arg;
2168                         continue;
2169                 }
2170                 if (!strcmp("--thin", arg)) {
2171                         use_internal_rev_list = 1;
2172                         thin = 1;
2173                         rp_av[1] = "--objects-edge";
2174                         continue;
2175                 }
2176                 if (!prefixcmp(arg, "--index-version=")) {
2177                         char *c;
2178                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2179                         if (pack_idx_default_version > 2)
2180                                 die("bad %s", arg);
2181                         if (*c == ',')
2182                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2183                         if (*c || pack_idx_off32_limit & 0x80000000)
2184                                 die("bad %s", arg);
2185                         continue;
2186                 }
2187                 usage(pack_usage);
2188         }
2189
2190         /* Traditionally "pack-objects [options] base extra" failed;
2191          * we would however want to take refs parameter that would
2192          * have been given to upstream rev-list ourselves, which means
2193          * we somehow want to say what the base name is.  So the
2194          * syntax would be:
2195          *
2196          * pack-objects [options] base <refs...>
2197          *
2198          * in other words, we would treat the first non-option as the
2199          * base_name and send everything else to the internal revision
2200          * walker.
2201          */
2202
2203         if (!pack_to_stdout)
2204                 base_name = argv[i++];
2205
2206         if (pack_to_stdout != !base_name)
2207                 usage(pack_usage);
2208
2209         if (!pack_to_stdout && !pack_size_limit)
2210                 pack_size_limit = pack_size_limit_cfg;
2211
2212         if (pack_to_stdout && pack_size_limit)
2213                 die("--max-pack-size cannot be used to build a pack for transfer.");
2214
2215         if (!pack_to_stdout && thin)
2216                 die("--thin cannot be used to build an indexable pack.");
2217
2218         if (keep_unreachable && unpack_unreachable)
2219                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2220
2221 #ifdef THREADED_DELTA_SEARCH
2222         if (!delta_search_threads)      /* --threads=0 means autodetect */
2223                 delta_search_threads = online_cpus();
2224 #endif
2225
2226         prepare_packed_git();
2227
2228         if (progress)
2229                 progress_state = start_progress("Counting objects", 0);
2230         if (!use_internal_rev_list)
2231                 read_object_list_from_stdin();
2232         else {
2233                 rp_av[rp_ac] = NULL;
2234                 get_object_list(rp_ac, rp_av);
2235         }
2236         if (include_tag && nr_result)
2237                 for_each_ref(add_ref_tag, NULL);
2238         stop_progress(&progress_state);
2239
2240         if (non_empty && !nr_result)
2241                 return 0;
2242         if (nr_result)
2243                 prepare_pack(window, depth);
2244         write_pack_file();
2245         if (progress)
2246                 fprintf(stderr, "Total %u (delta %u), reused %u (delta %u)\n",
2247                         written, written_delta, reused, reused_delta);
2248         return 0;
2249 }