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] [--keep-unreachable] \n\
  32         [<ref-list | <object-list]";
  33
  34 struct object_entry {
  35         struct pack_idx_entry idx;
  36         unsigned long size;     /* uncompressed size */
  37         struct packed_git *in_pack;     /* already in pack */
  38         off_t in_pack_offset;
  39         struct object_entry *delta;     /* delta base object */
  40         struct object_entry *delta_child; /* deltified objects who bases me */
  41         struct object_entry *delta_sibling; /* other deltified objects who
  42                                              * uses the same base as me
  43                                              */
  44         void *delta_data;       /* cached delta (uncompressed) */
  45         unsigned long delta_size;       /* delta data size (uncompressed) */
  46         unsigned long z_delta_size;     /* delta data size (compressed) */
  47         unsigned int hash;      /* name hint hash */
  48         enum object_type type;
  49         enum object_type in_pack_type;  /* could be delta */
  50         unsigned char in_pack_header_size;
  51         unsigned char preferred_base; /* we do not pack this, but is available
  52                                        * to be used as the base object to delta
  53                                        * objects against.
  54                                        */
  55         unsigned char no_try_delta;
  56 };
  57
  58 /*
  59  * Objects we are going to pack are collected in objects array (dynamically
  60  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  61  * in the order we see -- typically rev-list --objects order that gives us
  62  * nice "minimum seek" order.
  63  */
  64 static struct object_entry *objects;
  65 static struct pack_idx_entry **written_list;
  66 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
  67
  68 static int non_empty;
  69 static int reuse_delta = 1, reuse_object = 1;
  70 static int keep_unreachable, include_tag;
  71 static int local;
  72 static int incremental;
  73 static int allow_ofs_delta;
  74 static const char *base_name;
  75 static int progress = 1;
  76 static int window = 10;
  77 static uint32_t pack_size_limit, pack_size_limit_cfg;
  78 static int depth = 50;
  79 static int delta_search_threads = 1;
  80 static int pack_to_stdout;
  81 static int num_preferred_base;
  82 static struct progress *progress_state;
  83 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  84 static int pack_compression_seen;
  85
  86 static unsigned long delta_cache_size = 0;
  87 static unsigned long max_delta_cache_size = 0;
  88 static unsigned long cache_max_small_delta_size = 1000;
  89
  90 static unsigned long window_memory_limit = 0;
  91
  92 /*
  93  * The object names in objects array are hashed with this hashtable,
  94  * to help looking up the entry by object name.
  95  * This hashtable is built after all the objects are seen.
  96  */
  97 static int *object_ix;
  98 static int object_ix_hashsz;
  99
 100 /*
 101  * stats
 102  */
 103 static uint32_t written, written_delta;
 104 static uint32_t reused, reused_delta;
 105
 106
 107 static void *get_delta(struct object_entry *entry)
 108 {
 109         unsigned long size, base_size, delta_size;
 110         void *buf, *base_buf, *delta_buf;
 111         enum object_type type;
 112
 113         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 114         if (!buf)
 115                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 116         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
 117         if (!base_buf)
 118                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 119         delta_buf = diff_delta(base_buf, base_size,
 120                                buf, size, &delta_size, 0);
 121         if (!delta_buf || delta_size != entry->delta_size)
 122                 die("delta size changed");
 123         free(buf);
 124         free(base_buf);
 125         return delta_buf;
 126 }
 127
 128 static unsigned long do_compress(void **pptr, unsigned long size)
 129 {
 130         z_stream stream;
 131         void *in, *out;
 132         unsigned long maxsize;
 133
 134         memset(&stream, 0, sizeof(stream));
 135         deflateInit(&stream, pack_compression_level);
 136         maxsize = deflateBound(&stream, size);
 137
 138         in = *pptr;
 139         out = xmalloc(maxsize);
 140         *pptr = out;
 141
 142         stream.next_in = in;
 143         stream.avail_in = size;
 144         stream.next_out = out;
 145         stream.avail_out = maxsize;
 146         while (deflate(&stream, Z_FINISH) == Z_OK)
 147                 ; /* nothing */
 148         deflateEnd(&stream);
 149
 150         free(in);
 151         return stream.total_out;
 152 }
 153
 154 /*
 155  * The per-object header is a pretty dense thing, which is
 156  *  - first byte: low four bits are "size", then three bits of "type",
 157  *    and the high bit is "size continues".
 158  *  - each byte afterwards: low seven bits are size continuation,
 159  *    with the high bit being "size continues"
 160  */
 161 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 162 {
 163         int n = 1;
 164         unsigned char c;
 165
 166         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 167                 die("bad type %d", type);
 168
 169         c = (type << 4) | (size & 15);
 170         size >>= 4;
 171         while (size) {
 172                 *hdr++ = c | 0x80;
 173                 c = size & 0x7f;
 174                 size >>= 7;
 175                 n++;
 176         }
 177         *hdr = c;
 178         return n;
 179 }
 180
 181 /*
 182  * we are going to reuse the existing object data as is.  make
 183  * sure it is not corrupt.
 184  */
 185 static int check_pack_inflate(struct packed_git *p,
 186                 struct pack_window **w_curs,
 187                 off_t offset,
 188                 off_t len,
 189                 unsigned long expect)
 190 {
 191         z_stream stream;
 192         unsigned char fakebuf[4096], *in;
 193         int st;
 194
 195         memset(&stream, 0, sizeof(stream));
 196         inflateInit(&stream);
 197         do {
 198                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 199                 stream.next_in = in;
 200                 stream.next_out = fakebuf;
 201                 stream.avail_out = sizeof(fakebuf);
 202                 st = inflate(&stream, Z_FINISH);
 203                 offset += stream.next_in - in;
 204         } while (st == Z_OK || st == Z_BUF_ERROR);
 205         inflateEnd(&stream);
 206         return (st == Z_STREAM_END &&
 207                 stream.total_out == expect &&
 208                 stream.total_in == len) ? 0 : -1;
 209 }
 210
 211 static int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
 212                           off_t offset, off_t len, unsigned int nr)
 213 {
 214         const uint32_t *index_crc;
 215         uint32_t data_crc = crc32(0, Z_NULL, 0);
 216
 217         do {
 218                 unsigned int avail;
 219                 void *data = use_pack(p, w_curs, offset, &avail);
 220                 if (avail > len)
 221                         avail = len;
 222                 data_crc = crc32(data_crc, data, avail);
 223                 offset += avail;
 224                 len -= avail;
 225         } while (len);
 226
 227         index_crc = p->index_data;
 228         index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
 229
 230         return data_crc != ntohl(*index_crc);
 231 }
 232
 233 static void copy_pack_data(struct sha1file *f,
 234                 struct packed_git *p,
 235                 struct pack_window **w_curs,
 236                 off_t offset,
 237                 off_t len)
 238 {
 239         unsigned char *in;
 240         unsigned int avail;
 241
 242         while (len) {
 243                 in = use_pack(p, w_curs, offset, &avail);
 244                 if (avail > len)
 245                         avail = (unsigned int)len;
 246                 sha1write(f, in, avail);
 247                 offset += avail;
 248                 len -= avail;
 249         }
 250 }
 251
 252 static unsigned long write_object(struct sha1file *f,
 253                                   struct object_entry *entry,
 254                                   off_t write_offset)
 255 {
 256         unsigned long size, limit, datalen;
 257         void *buf;
 258         unsigned char header[10], dheader[10];
 259         unsigned hdrlen;
 260         enum object_type type;
 261         int usable_delta, to_reuse;
 262
 263         if (!pack_to_stdout)
 264                 crc32_begin(f);
 265
 266         type = entry->type;
 267
 268         /* write limit if limited packsize and not first object */
 269         limit = pack_size_limit && nr_written ?
 270                         pack_size_limit - write_offset : 0;
 271
 272         if (!entry->delta)
 273                 usable_delta = 0;       /* no delta */
 274         else if (!pack_size_limit)
 275                usable_delta = 1;        /* unlimited packfile */
 276         else if (entry->delta->idx.offset == (off_t)-1)
 277                 usable_delta = 0;       /* base was written to another pack */
 278         else if (entry->delta->idx.offset)
 279                 usable_delta = 1;       /* base already exists in this pack */
 280         else
 281                 usable_delta = 0;       /* base could end up in another pack */
 282
 283         if (!reuse_object)
 284                 to_reuse = 0;   /* explicit */
 285         else if (!entry->in_pack)
 286                 to_reuse = 0;   /* can't reuse what we don't have */
 287         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
 288                                 /* check_object() decided it for us ... */
 289                 to_reuse = usable_delta;
 290                                 /* ... but pack split may override that */
 291         else if (type != entry->in_pack_type)
 292                 to_reuse = 0;   /* pack has delta which is unusable */
 293         else if (entry->delta)
 294                 to_reuse = 0;   /* we want to pack afresh */
 295         else
 296                 to_reuse = 1;   /* we have it in-pack undeltified,
 297                                  * and we do not need to deltify it.
 298                                  */
 299
 300         if (!to_reuse) {
 301                 if (!usable_delta) {
 302                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 303                         if (!buf)
 304                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 305                         /*
 306                          * make sure no cached delta data remains from a
 307                          * previous attempt before a pack split occured.
 308                          */
 309                         free(entry->delta_data);
 310                         entry->delta_data = NULL;
 311                         entry->z_delta_size = 0;
 312                 } else if (entry->delta_data) {
 313                         size = entry->delta_size;
 314                         buf = entry->delta_data;
 315                         entry->delta_data = NULL;
 316                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 317                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 318                 } else {
 319                         buf = get_delta(entry);
 320                         size = entry->delta_size;
 321                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 322                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 323                 }
 324
 325                 if (entry->z_delta_size)
 326                         datalen = entry->z_delta_size;
 327                 else
 328                         datalen = do_compress(&buf, size);
 329
 330                 /*
 331                  * The object header is a byte of 'type' followed by zero or
 332                  * more bytes of length.
 333                  */
 334                 hdrlen = encode_header(type, size, header);
 335
 336                 if (type == OBJ_OFS_DELTA) {
 337                         /*
 338                          * Deltas with relative base contain an additional
 339                          * encoding of the relative offset for the delta
 340                          * base from this object's position in the pack.
 341                          */
 342                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 343                         unsigned pos = sizeof(dheader) - 1;
 344                         dheader[pos] = ofs & 127;
 345                         while (ofs >>= 7)
 346                                 dheader[--pos] = 128 | (--ofs & 127);
 347                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 348                                 free(buf);
 349                                 return 0;
 350                         }
 351                         sha1write(f, header, hdrlen);
 352                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 353                         hdrlen += sizeof(dheader) - pos;
 354                 } else if (type == OBJ_REF_DELTA) {
 355                         /*
 356                          * Deltas with a base reference contain
 357                          * an additional 20 bytes for the base sha1.
 358                          */
 359                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 360                                 free(buf);
 361                                 return 0;
 362                         }
 363                         sha1write(f, header, hdrlen);
 364                         sha1write(f, entry->delta->idx.sha1, 20);
 365                         hdrlen += 20;
 366                 } else {
 367                         if (limit && hdrlen + datalen + 20 >= limit) {
 368                                 free(buf);
 369                                 return 0;
 370                         }
 371                         sha1write(f, header, hdrlen);
 372                 }
 373                 sha1write(f, buf, datalen);
 374                 free(buf);
 375         }
 376         else {
 377                 struct packed_git *p = entry->in_pack;
 378                 struct pack_window *w_curs = NULL;
 379                 struct revindex_entry *revidx;
 380                 off_t offset;
 381
 382                 if (entry->delta) {
 383                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 384                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 385                         reused_delta++;
 386                 }
 387                 hdrlen = encode_header(type, entry->size, header);
 388                 offset = entry->in_pack_offset;
 389                 revidx = find_pack_revindex(p, offset);
 390                 datalen = revidx[1].offset - offset;
 391                 if (!pack_to_stdout && p->index_version > 1 &&
 392                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
 393                         die("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 394                 offset += entry->in_pack_header_size;
 395                 datalen -= entry->in_pack_header_size;
 396                 if (type == OBJ_OFS_DELTA) {
 397                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 398                         unsigned pos = sizeof(dheader) - 1;
 399                         dheader[pos] = ofs & 127;
 400                         while (ofs >>= 7)
 401                                 dheader[--pos] = 128 | (--ofs & 127);
 402                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit)
 403                                 return 0;
 404                         sha1write(f, header, hdrlen);
 405                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 406                         hdrlen += sizeof(dheader) - pos;
 407                 } else if (type == OBJ_REF_DELTA) {
 408                         if (limit && hdrlen + 20 + datalen + 20 >= limit)
 409                                 return 0;
 410                         sha1write(f, header, hdrlen);
 411                         sha1write(f, entry->delta->idx.sha1, 20);
 412                         hdrlen += 20;
 413                 } else {
 414                         if (limit && hdrlen + datalen + 20 >= limit)
 415                                 return 0;
 416                         sha1write(f, header, hdrlen);
 417                 }
 418
 419                 if (!pack_to_stdout && p->index_version == 1 &&
 420                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
 421                         die("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 422                 copy_pack_data(f, p, &w_curs, offset, datalen);
 423                 unuse_pack(&w_curs);
 424                 reused++;
 425         }
 426         if (usable_delta)
 427                 written_delta++;
 428         written++;
 429         if (!pack_to_stdout)
 430                 entry->idx.crc32 = crc32_end(f);
 431         return hdrlen + datalen;
 432 }
 433
 434 static off_t write_one(struct sha1file *f,
 435                                struct object_entry *e,
 436                                off_t offset)
 437 {
 438         unsigned long size;
 439
 440         /* offset is non zero if object is written already. */
 441         if (e->idx.offset || e->preferred_base)
 442                 return offset;
 443
 444         /* if we are deltified, write out base object first. */
 445         if (e->delta) {
 446                 offset = write_one(f, e->delta, offset);
 447                 if (!offset)
 448                         return 0;
 449         }
 450
 451         e->idx.offset = offset;
 452         size = write_object(f, e, offset);
 453         if (!size) {
 454                 e->idx.offset = 0;
 455                 return 0;
 456         }
 457         written_list[nr_written++] = &e->idx;
 458
 459         /* make sure off_t is sufficiently large not to wrap */
 460         if (offset > offset + size)
 461                 die("pack too large for current definition of off_t");
 462         return offset + size;
 463 }
 464
 465 /* forward declaration for write_pack_file */
 466 static int adjust_perm(const char *path, mode_t mode);
 467
 468 static void write_pack_file(void)
 469 {
 470         uint32_t i = 0, j;
 471         struct sha1file *f;
 472         off_t offset, offset_one, last_obj_offset = 0;
 473         struct pack_header hdr;
 474         uint32_t nr_remaining = nr_result;
 475         time_t last_mtime = 0;
 476
 477         if (progress > pack_to_stdout)
 478                 progress_state = start_progress("Writing objects", nr_result);
 479         written_list = xmalloc(nr_objects * sizeof(*written_list));
 480
 481         do {
 482                 unsigned char sha1[20];
 483                 char *pack_tmp_name = NULL;
 484
 485                 if (pack_to_stdout) {
 486                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 487                 } else {
 488                         char tmpname[PATH_MAX];
 489                         int fd;
 490                         snprintf(tmpname, sizeof(tmpname),
 491                                  "%s/tmp_pack_XXXXXX", get_object_directory());
 492                         fd = xmkstemp(tmpname);
 493                         pack_tmp_name = xstrdup(tmpname);
 494                         f = sha1fd(fd, pack_tmp_name);
 495                 }
 496
 497                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
 498                 hdr.hdr_version = htonl(PACK_VERSION);
 499                 hdr.hdr_entries = htonl(nr_remaining);
 500                 sha1write(f, &hdr, sizeof(hdr));
 501                 offset = sizeof(hdr);
 502                 nr_written = 0;
 503                 for (; i < nr_objects; i++) {
 504                         last_obj_offset = offset;
 505                         offset_one = write_one(f, objects + i, offset);
 506                         if (!offset_one)
 507                                 break;
 508                         offset = offset_one;
 509                         display_progress(progress_state, written);
 510                 }
 511
 512                 /*
 513                  * Did we write the wrong # entries in the header?
 514                  * If so, rewrite it like in fast-import
 515                  */
 516                 if (pack_to_stdout || nr_written == nr_remaining) {
 517                         sha1close(f, sha1, 1);
 518                 } else {
 519                         int fd = sha1close(f, NULL, 0);
 520                         fixup_pack_header_footer(fd, sha1, pack_tmp_name, nr_written);
 521                         close(fd);
 522                 }
 523
 524                 if (!pack_to_stdout) {
 525                         mode_t mode = umask(0);
 526                         struct stat st;
 527                         char *idx_tmp_name, tmpname[PATH_MAX];
 528
 529                         umask(mode);
 530                         mode = 0444 & ~mode;
 531
 532                         idx_tmp_name = write_idx_file(NULL, written_list,
 533                                                       nr_written, sha1);
 534
 535                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 536                                  base_name, sha1_to_hex(sha1));
 537                         if (adjust_perm(pack_tmp_name, mode))
 538                                 die("unable to make temporary pack file readable: %s",
 539                                     strerror(errno));
 540                         if (rename(pack_tmp_name, tmpname))
 541                                 die("unable to rename temporary pack file: %s",
 542                                     strerror(errno));
 543
 544                         /*
 545                          * Packs are runtime accessed in their mtime
 546                          * order since newer packs are more likely to contain
 547                          * younger objects.  So if we are creating multiple
 548                          * packs then we should modify the mtime of later ones
 549                          * to preserve this property.
 550                          */
 551                         if (stat(tmpname, &st) < 0) {
 552                                 warning("failed to stat %s: %s",
 553                                         tmpname, strerror(errno));
 554                         } else if (!last_mtime) {
 555                                 last_mtime = st.st_mtime;
 556                         } else {
 557                                 struct utimbuf utb;
 558                                 utb.actime = st.st_atime;
 559                                 utb.modtime = --last_mtime;
 560                                 if (utime(tmpname, &utb) < 0)
 561                                         warning("failed utime() on %s: %s",
 562                                                 tmpname, strerror(errno));
 563                         }
 564
 565                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 566                                  base_name, sha1_to_hex(sha1));
 567                         if (adjust_perm(idx_tmp_name, mode))
 568                                 die("unable to make temporary index file readable: %s",
 569                                     strerror(errno));
 570                         if (rename(idx_tmp_name, tmpname))
 571                                 die("unable to rename temporary index file: %s",
 572                                     strerror(errno));
 573
 574                         free(idx_tmp_name);
 575                         free(pack_tmp_name);
 576                         puts(sha1_to_hex(sha1));
 577                 }
 578
 579                 /* mark written objects as written to previous pack */
 580                 for (j = 0; j < nr_written; j++) {
 581                         written_list[j]->offset = (off_t)-1;
 582                 }
 583                 nr_remaining -= nr_written;
 584         } while (nr_remaining && i < nr_objects);
 585
 586         free(written_list);
 587         stop_progress(&progress_state);
 588         if (written != nr_result)
 589                 die("wrote %u objects while expecting %u", written, nr_result);
 590         /*
 591          * We have scanned through [0 ... i).  Since we have written
 592          * the correct number of objects,  the remaining [i ... nr_objects)
 593          * items must be either already written (due to out-of-order delta base)
 594          * or a preferred base.  Count those which are neither and complain if any.
 595          */
 596         for (j = 0; i < nr_objects; i++) {
 597                 struct object_entry *e = objects + i;
 598                 j += !e->idx.offset && !e->preferred_base;
 599         }
 600         if (j)
 601                 die("wrote %u objects as expected but %u unwritten", written, j);
 602 }
 603
 604 static int locate_object_entry_hash(const unsigned char *sha1)
 605 {
 606         int i;
 607         unsigned int ui;
 608         memcpy(&ui, sha1, sizeof(unsigned int));
 609         i = ui % object_ix_hashsz;
 610         while (0 < object_ix[i]) {
 611                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 612                         return i;
 613                 if (++i == object_ix_hashsz)
 614                         i = 0;
 615         }
 616         return -1 - i;
 617 }
 618
 619 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 620 {
 621         int i;
 622
 623         if (!object_ix_hashsz)
 624                 return NULL;
 625
 626         i = locate_object_entry_hash(sha1);
 627         if (0 <= i)
 628                 return &objects[object_ix[i]-1];
 629         return NULL;
 630 }
 631
 632 static void rehash_objects(void)
 633 {
 634         uint32_t i;
 635         struct object_entry *oe;
 636
 637         object_ix_hashsz = nr_objects * 3;
 638         if (object_ix_hashsz < 1024)
 639                 object_ix_hashsz = 1024;
 640         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 641         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 642         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 643                 int ix = locate_object_entry_hash(oe->idx.sha1);
 644                 if (0 <= ix)
 645                         continue;
 646                 ix = -1 - ix;
 647                 object_ix[ix] = i + 1;
 648         }
 649 }
 650
 651 static unsigned name_hash(const char *name)
 652 {
 653         unsigned char c;
 654         unsigned hash = 0;
 655
 656         if (!name)
 657                 return 0;
 658
 659         /*
 660          * This effectively just creates a sortable number from the
 661          * last sixteen non-whitespace characters. Last characters
 662          * count "most", so things that end in ".c" sort together.
 663          */
 664         while ((c = *name++) != 0) {
 665                 if (isspace(c))
 666                         continue;
 667                 hash = (hash >> 2) + (c << 24);
 668         }
 669         return hash;
 670 }
 671
 672 static void setup_delta_attr_check(struct git_attr_check *check)
 673 {
 674         static struct git_attr *attr_delta;
 675
 676         if (!attr_delta)
 677                 attr_delta = git_attr("delta", 5);
 678
 679         check[0].attr = attr_delta;
 680 }
 681
 682 static int no_try_delta(const char *path)
 683 {
 684         struct git_attr_check check[1];
 685
 686         setup_delta_attr_check(check);
 687         if (git_checkattr(path, ARRAY_SIZE(check), check))
 688                 return 0;
 689         if (ATTR_FALSE(check->value))
 690                 return 1;
 691         return 0;
 692 }
 693
 694 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 695                             const char *name, int exclude)
 696 {
 697         struct object_entry *entry;
 698         struct packed_git *p, *found_pack = NULL;
 699         off_t found_offset = 0;
 700         int ix;
 701         unsigned hash = name_hash(name);
 702
 703         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 704         if (ix >= 0) {
 705                 if (exclude) {
 706                         entry = objects + object_ix[ix] - 1;
 707                         if (!entry->preferred_base)
 708                                 nr_result--;
 709                         entry->preferred_base = 1;
 710                 }
 711                 return 0;
 712         }
 713
 714         for (p = packed_git; p; p = p->next) {
 715                 off_t offset = find_pack_entry_one(sha1, p);
 716                 if (offset) {
 717                         if (!found_pack) {
 718                                 found_offset = offset;
 719                                 found_pack = p;
 720                         }
 721                         if (exclude)
 722                                 break;
 723                         if (incremental)
 724                                 return 0;
 725                         if (local && !p->pack_local)
 726                                 return 0;
 727                 }
 728         }
 729
 730         if (nr_objects >= nr_alloc) {
 731                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 732                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 733         }
 734
 735         entry = objects + nr_objects++;
 736         memset(entry, 0, sizeof(*entry));
 737         hashcpy(entry->idx.sha1, sha1);
 738         entry->hash = hash;
 739         if (type)
 740                 entry->type = type;
 741         if (exclude)
 742                 entry->preferred_base = 1;
 743         else
 744                 nr_result++;
 745         if (found_pack) {
 746                 entry->in_pack = found_pack;
 747                 entry->in_pack_offset = found_offset;
 748         }
 749
 750         if (object_ix_hashsz * 3 <= nr_objects * 4)
 751                 rehash_objects();
 752         else
 753                 object_ix[-1 - ix] = nr_objects;
 754
 755         display_progress(progress_state, nr_objects);
 756
 757         if (name && no_try_delta(name))
 758                 entry->no_try_delta = 1;
 759
 760         return 1;
 761 }
 762
 763 struct pbase_tree_cache {
 764         unsigned char sha1[20];
 765         int ref;
 766         int temporary;
 767         void *tree_data;
 768         unsigned long tree_size;
 769 };
 770
 771 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 772 static int pbase_tree_cache_ix(const unsigned char *sha1)
 773 {
 774         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 775 }
 776 static int pbase_tree_cache_ix_incr(int ix)
 777 {
 778         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 779 }
 780
 781 static struct pbase_tree {
 782         struct pbase_tree *next;
 783         /* This is a phony "cache" entry; we are not
 784          * going to evict it nor find it through _get()
 785          * mechanism -- this is for the toplevel node that
 786          * would almost always change with any commit.
 787          */
 788         struct pbase_tree_cache pcache;
 789 } *pbase_tree;
 790
 791 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 792 {
 793         struct pbase_tree_cache *ent, *nent;
 794         void *data;
 795         unsigned long size;
 796         enum object_type type;
 797         int neigh;
 798         int my_ix = pbase_tree_cache_ix(sha1);
 799         int available_ix = -1;
 800
 801         /* pbase-tree-cache acts as a limited hashtable.
 802          * your object will be found at your index or within a few
 803          * slots after that slot if it is cached.
 804          */
 805         for (neigh = 0; neigh < 8; neigh++) {
 806                 ent = pbase_tree_cache[my_ix];
 807                 if (ent && !hashcmp(ent->sha1, sha1)) {
 808                         ent->ref++;
 809                         return ent;
 810                 }
 811                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 812                          ((0 <= available_ix) &&
 813                           (!ent && pbase_tree_cache[available_ix])))
 814                         available_ix = my_ix;
 815                 if (!ent)
 816                         break;
 817                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 818         }
 819
 820         /* Did not find one.  Either we got a bogus request or
 821          * we need to read and perhaps cache.
 822          */
 823         data = read_sha1_file(sha1, &type, &size);
 824         if (!data)
 825                 return NULL;
 826         if (type != OBJ_TREE) {
 827                 free(data);
 828                 return NULL;
 829         }
 830
 831         /* We need to either cache or return a throwaway copy */
 832
 833         if (available_ix < 0)
 834                 ent = NULL;
 835         else {
 836                 ent = pbase_tree_cache[available_ix];
 837                 my_ix = available_ix;
 838         }
 839
 840         if (!ent) {
 841                 nent = xmalloc(sizeof(*nent));
 842                 nent->temporary = (available_ix < 0);
 843         }
 844         else {
 845                 /* evict and reuse */
 846                 free(ent->tree_data);
 847                 nent = ent;
 848         }
 849         hashcpy(nent->sha1, sha1);
 850         nent->tree_data = data;
 851         nent->tree_size = size;
 852         nent->ref = 1;
 853         if (!nent->temporary)
 854                 pbase_tree_cache[my_ix] = nent;
 855         return nent;
 856 }
 857
 858 static void pbase_tree_put(struct pbase_tree_cache *cache)
 859 {
 860         if (!cache->temporary) {
 861                 cache->ref--;
 862                 return;
 863         }
 864         free(cache->tree_data);
 865         free(cache);
 866 }
 867
 868 static int name_cmp_len(const char *name)
 869 {
 870         int i;
 871         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 872                 ;
 873         return i;
 874 }
 875
 876 static void add_pbase_object(struct tree_desc *tree,
 877                              const char *name,
 878                              int cmplen,
 879                              const char *fullname)
 880 {
 881         struct name_entry entry;
 882         int cmp;
 883
 884         while (tree_entry(tree,&entry)) {
 885                 if (S_ISGITLINK(entry.mode))
 886                         continue;
 887                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 888                       memcmp(name, entry.path, cmplen);
 889                 if (cmp > 0)
 890                         continue;
 891                 if (cmp < 0)
 892                         return;
 893                 if (name[cmplen] != '/') {
 894                         add_object_entry(entry.sha1,
 895                                          object_type(entry.mode),
 896                                          fullname, 1);
 897                         return;
 898                 }
 899                 if (S_ISDIR(entry.mode)) {
 900                         struct tree_desc sub;
 901                         struct pbase_tree_cache *tree;
 902                         const char *down = name+cmplen+1;
 903                         int downlen = name_cmp_len(down);
 904
 905                         tree = pbase_tree_get(entry.sha1);
 906                         if (!tree)
 907                                 return;
 908                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 909
 910                         add_pbase_object(&sub, down, downlen, fullname);
 911                         pbase_tree_put(tree);
 912                 }
 913         }
 914 }
 915
 916 static unsigned *done_pbase_paths;
 917 static int done_pbase_paths_num;
 918 static int done_pbase_paths_alloc;
 919 static int done_pbase_path_pos(unsigned hash)
 920 {
 921         int lo = 0;
 922         int hi = done_pbase_paths_num;
 923         while (lo < hi) {
 924                 int mi = (hi + lo) / 2;
 925                 if (done_pbase_paths[mi] == hash)
 926                         return mi;
 927                 if (done_pbase_paths[mi] < hash)
 928                         hi = mi;
 929                 else
 930                         lo = mi + 1;
 931         }
 932         return -lo-1;
 933 }
 934
 935 static int check_pbase_path(unsigned hash)
 936 {
 937         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 938         if (0 <= pos)
 939                 return 1;
 940         pos = -pos - 1;
 941         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 942                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 943                 done_pbase_paths = xrealloc(done_pbase_paths,
 944                                             done_pbase_paths_alloc *
 945                                             sizeof(unsigned));
 946         }
 947         done_pbase_paths_num++;
 948         if (pos < done_pbase_paths_num)
 949                 memmove(done_pbase_paths + pos + 1,
 950                         done_pbase_paths + pos,
 951                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 952         done_pbase_paths[pos] = hash;
 953         return 0;
 954 }
 955
 956 static void add_preferred_base_object(const char *name)
 957 {
 958         struct pbase_tree *it;
 959         int cmplen;
 960         unsigned hash = name_hash(name);
 961
 962         if (!num_preferred_base || check_pbase_path(hash))
 963                 return;
 964
 965         cmplen = name_cmp_len(name);
 966         for (it = pbase_tree; it; it = it->next) {
 967                 if (cmplen == 0) {
 968                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 969                 }
 970                 else {
 971                         struct tree_desc tree;
 972                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 973                         add_pbase_object(&tree, name, cmplen, name);
 974                 }
 975         }
 976 }
 977
 978 static void add_preferred_base(unsigned char *sha1)
 979 {
 980         struct pbase_tree *it;
 981         void *data;
 982         unsigned long size;
 983         unsigned char tree_sha1[20];
 984
 985         if (window <= num_preferred_base++)
 986                 return;
 987
 988         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 989         if (!data)
 990                 return;
 991
 992         for (it = pbase_tree; it; it = it->next) {
 993                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 994                         free(data);
 995                         return;
 996                 }
 997         }
 998
 999         it = xcalloc(1, sizeof(*it));
1000         it->next = pbase_tree;
1001         pbase_tree = it;
1002
1003         hashcpy(it->pcache.sha1, tree_sha1);
1004         it->pcache.tree_data = data;
1005         it->pcache.tree_size = size;
1006 }
1007
1008 static void check_object(struct object_entry *entry)
1009 {
1010         if (entry->in_pack) {
1011                 struct packed_git *p = entry->in_pack;
1012                 struct pack_window *w_curs = NULL;
1013                 const unsigned char *base_ref = NULL;
1014                 struct object_entry *base_entry;
1015                 unsigned long used, used_0;
1016                 unsigned int avail;
1017                 off_t ofs;
1018                 unsigned char *buf, c;
1019
1020                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1021
1022                 /*
1023                  * We want in_pack_type even if we do not reuse delta
1024                  * since non-delta representations could still be reused.
1025                  */
1026                 used = unpack_object_header_gently(buf, avail,
1027                                                    &entry->in_pack_type,
1028                                                    &entry->size);
1029
1030                 /*
1031                  * Determine if this is a delta and if so whether we can
1032                  * reuse it or not.  Otherwise let's find out as cheaply as
1033                  * possible what the actual type and size for this object is.
1034                  */
1035                 switch (entry->in_pack_type) {
1036                 default:
1037                         /* Not a delta hence we've already got all we need. */
1038                         entry->type = entry->in_pack_type;
1039                         entry->in_pack_header_size = used;
1040                         unuse_pack(&w_curs);
1041                         return;
1042                 case OBJ_REF_DELTA:
1043                         if (reuse_delta && !entry->preferred_base)
1044                                 base_ref = use_pack(p, &w_curs,
1045                                                 entry->in_pack_offset + used, NULL);
1046                         entry->in_pack_header_size = used + 20;
1047                         break;
1048                 case OBJ_OFS_DELTA:
1049                         buf = use_pack(p, &w_curs,
1050                                        entry->in_pack_offset + used, NULL);
1051                         used_0 = 0;
1052                         c = buf[used_0++];
1053                         ofs = c & 127;
1054                         while (c & 128) {
1055                                 ofs += 1;
1056                                 if (!ofs || MSB(ofs, 7))
1057                                         die("delta base offset overflow in pack for %s",
1058                                             sha1_to_hex(entry->idx.sha1));
1059                                 c = buf[used_0++];
1060                                 ofs = (ofs << 7) + (c & 127);
1061                         }
1062                         if (ofs >= entry->in_pack_offset)
1063                                 die("delta base offset out of bound for %s",
1064                                     sha1_to_hex(entry->idx.sha1));
1065                         ofs = entry->in_pack_offset - ofs;
1066                         if (reuse_delta && !entry->preferred_base) {
1067                                 struct revindex_entry *revidx;
1068                                 revidx = find_pack_revindex(p, ofs);
1069                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1070                         }
1071                         entry->in_pack_header_size = used + used_0;
1072                         break;
1073                 }
1074
1075                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1076                         /*
1077                          * If base_ref was set above that means we wish to
1078                          * reuse delta data, and we even found that base
1079                          * in the list of objects we want to pack. Goodie!
1080                          *
1081                          * Depth value does not matter - find_deltas() will
1082                          * never consider reused delta as the base object to
1083                          * deltify other objects against, in order to avoid
1084                          * circular deltas.
1085                          */
1086                         entry->type = entry->in_pack_type;
1087                         entry->delta = base_entry;
1088                         entry->delta_sibling = base_entry->delta_child;
1089                         base_entry->delta_child = entry;
1090                         unuse_pack(&w_curs);
1091                         return;
1092                 }
1093
1094                 if (entry->type) {
1095                         /*
1096                          * This must be a delta and we already know what the
1097                          * final object type is.  Let's extract the actual
1098                          * object size from the delta header.
1099                          */
1100                         entry->size = get_size_from_delta(p, &w_curs,
1101                                         entry->in_pack_offset + entry->in_pack_header_size);
1102                         unuse_pack(&w_curs);
1103                         return;
1104                 }
1105
1106                 /*
1107                  * No choice but to fall back to the recursive delta walk
1108                  * with sha1_object_info() to find about the object type
1109                  * at this point...
1110                  */
1111                 unuse_pack(&w_curs);
1112         }
1113
1114         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1115         if (entry->type < 0)
1116                 die("unable to get type of object %s",
1117                     sha1_to_hex(entry->idx.sha1));
1118 }
1119
1120 static int pack_offset_sort(const void *_a, const void *_b)
1121 {
1122         const struct object_entry *a = *(struct object_entry **)_a;
1123         const struct object_entry *b = *(struct object_entry **)_b;
1124
1125         /* avoid filesystem trashing with loose objects */
1126         if (!a->in_pack && !b->in_pack)
1127                 return hashcmp(a->idx.sha1, b->idx.sha1);
1128
1129         if (a->in_pack < b->in_pack)
1130                 return -1;
1131         if (a->in_pack > b->in_pack)
1132                 return 1;
1133         return a->in_pack_offset < b->in_pack_offset ? -1 :
1134                         (a->in_pack_offset > b->in_pack_offset);
1135 }
1136
1137 static void get_object_details(void)
1138 {
1139         uint32_t i;
1140         struct object_entry **sorted_by_offset;
1141
1142         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1143         for (i = 0; i < nr_objects; i++)
1144                 sorted_by_offset[i] = objects + i;
1145         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1146
1147         init_pack_revindex();
1148
1149         for (i = 0; i < nr_objects; i++)
1150                 check_object(sorted_by_offset[i]);
1151
1152         free(sorted_by_offset);
1153 }
1154
1155 /*
1156  * We search for deltas in a list sorted by type, by filename hash, and then
1157  * by size, so that we see progressively smaller and smaller files.
1158  * That's because we prefer deltas to be from the bigger file
1159  * to the smaller -- deletes are potentially cheaper, but perhaps
1160  * more importantly, the bigger file is likely the more recent
1161  * one.  The deepest deltas are therefore the oldest objects which are
1162  * less susceptible to be accessed often.
1163  */
1164 static int type_size_sort(const void *_a, const void *_b)
1165 {
1166         const struct object_entry *a = *(struct object_entry **)_a;
1167         const struct object_entry *b = *(struct object_entry **)_b;
1168
1169         if (a->type > b->type)
1170                 return -1;
1171         if (a->type < b->type)
1172                 return 1;
1173         if (a->hash > b->hash)
1174                 return -1;
1175         if (a->hash < b->hash)
1176                 return 1;
1177         if (a->preferred_base > b->preferred_base)
1178                 return -1;
1179         if (a->preferred_base < b->preferred_base)
1180                 return 1;
1181         if (a->size > b->size)
1182                 return -1;
1183         if (a->size < b->size)
1184                 return 1;
1185         return a < b ? -1 : (a > b);  /* newest first */
1186 }
1187
1188 struct unpacked {
1189         struct object_entry *entry;
1190         void *data;
1191         struct delta_index *index;
1192         unsigned depth;
1193 };
1194
1195 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1196                            unsigned long delta_size)
1197 {
1198         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1199                 return 0;
1200
1201         if (delta_size < cache_max_small_delta_size)
1202                 return 1;
1203
1204         /* cache delta, if objects are large enough compared to delta size */
1205         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1206                 return 1;
1207
1208         return 0;
1209 }
1210
1211 #ifdef THREADED_DELTA_SEARCH
1212
1213 static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1214 #define read_lock()             pthread_mutex_lock(&read_mutex)
1215 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1216
1217 static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1218 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1219 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1220
1221 static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1222 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1223 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1224
1225 #else
1226
1227 #define read_lock()             (void)0
1228 #define read_unlock()           (void)0
1229 #define cache_lock()            (void)0
1230 #define cache_unlock()          (void)0
1231 #define progress_lock()         (void)0
1232 #define progress_unlock()       (void)0
1233
1234 #endif
1235
1236 static int try_delta(struct unpacked *trg, struct unpacked *src,
1237                      unsigned max_depth, unsigned long *mem_usage)
1238 {
1239         struct object_entry *trg_entry = trg->entry;
1240         struct object_entry *src_entry = src->entry;
1241         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1242         unsigned ref_depth;
1243         enum object_type type;
1244         void *delta_buf;
1245
1246         /* Don't bother doing diffs between different types */
1247         if (trg_entry->type != src_entry->type)
1248                 return -1;
1249
1250         /*
1251          * We do not bother to try a delta that we discarded
1252          * on an earlier try, but only when reusing delta data.
1253          */
1254         if (reuse_delta && trg_entry->in_pack &&
1255             trg_entry->in_pack == src_entry->in_pack &&
1256             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1257             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1258                 return 0;
1259
1260         /* Let's not bust the allowed depth. */
1261         if (src->depth >= max_depth)
1262                 return 0;
1263
1264         /* Now some size filtering heuristics. */
1265         trg_size = trg_entry->size;
1266         if (!trg_entry->delta) {
1267                 max_size = trg_size/2 - 20;
1268                 ref_depth = 1;
1269         } else {
1270                 max_size = trg_entry->delta_size;
1271                 ref_depth = trg->depth;
1272         }
1273         max_size = max_size * (max_depth - src->depth) /
1274                                                 (max_depth - ref_depth + 1);
1275         if (max_size == 0)
1276                 return 0;
1277         src_size = src_entry->size;
1278         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1279         if (sizediff >= max_size)
1280                 return 0;
1281         if (trg_size < src_size / 32)
1282                 return 0;
1283
1284         /* Load data if not already done */
1285         if (!trg->data) {
1286                 read_lock();
1287                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1288                 read_unlock();
1289                 if (!trg->data)
1290                         die("object %s cannot be read",
1291                             sha1_to_hex(trg_entry->idx.sha1));
1292                 if (sz != trg_size)
1293                         die("object %s inconsistent object length (%lu vs %lu)",
1294                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1295                 *mem_usage += sz;
1296         }
1297         if (!src->data) {
1298                 read_lock();
1299                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1300                 read_unlock();
1301                 if (!src->data)
1302                         die("object %s cannot be read",
1303                             sha1_to_hex(src_entry->idx.sha1));
1304                 if (sz != src_size)
1305                         die("object %s inconsistent object length (%lu vs %lu)",
1306                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1307                 *mem_usage += sz;
1308         }
1309         if (!src->index) {
1310                 src->index = create_delta_index(src->data, src_size);
1311                 if (!src->index) {
1312                         static int warned = 0;
1313                         if (!warned++)
1314                                 warning("suboptimal pack - out of memory");
1315                         return 0;
1316                 }
1317                 *mem_usage += sizeof_delta_index(src->index);
1318         }
1319
1320         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1321         if (!delta_buf)
1322                 return 0;
1323
1324         if (trg_entry->delta) {
1325                 /* Prefer only shallower same-sized deltas. */
1326                 if (delta_size == trg_entry->delta_size &&
1327                     src->depth + 1 >= trg->depth) {
1328                         free(delta_buf);
1329                         return 0;
1330                 }
1331         }
1332
1333         /*
1334          * Handle memory allocation outside of the cache
1335          * accounting lock.  Compiler will optimize the strangeness
1336          * away when THREADED_DELTA_SEARCH is not defined.
1337          */
1338         free(trg_entry->delta_data);
1339         cache_lock();
1340         if (trg_entry->delta_data) {
1341                 delta_cache_size -= trg_entry->delta_size;
1342                 trg_entry->delta_data = NULL;
1343         }
1344         if (delta_cacheable(src_size, trg_size, delta_size)) {
1345                 delta_cache_size += delta_size;
1346                 cache_unlock();
1347                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1348         } else {
1349                 cache_unlock();
1350                 free(delta_buf);
1351         }
1352
1353         trg_entry->delta = src_entry;
1354         trg_entry->delta_size = delta_size;
1355         trg->depth = src->depth + 1;
1356
1357         return 1;
1358 }
1359
1360 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1361 {
1362         struct object_entry *child = me->delta_child;
1363         unsigned int m = n;
1364         while (child) {
1365                 unsigned int c = check_delta_limit(child, n + 1);
1366                 if (m < c)
1367                         m = c;
1368                 child = child->delta_sibling;
1369         }
1370         return m;
1371 }
1372
1373 static unsigned long free_unpacked(struct unpacked *n)
1374 {
1375         unsigned long freed_mem = sizeof_delta_index(n->index);
1376         free_delta_index(n->index);
1377         n->index = NULL;
1378         if (n->data) {
1379                 freed_mem += n->entry->size;
1380                 free(n->data);
1381                 n->data = NULL;
1382         }
1383         n->entry = NULL;
1384         n->depth = 0;
1385         return freed_mem;
1386 }
1387
1388 static void find_deltas(struct object_entry **list, unsigned *list_size,
1389                         int window, int depth, unsigned *processed)
1390 {
1391         uint32_t i, idx = 0, count = 0;
1392         unsigned int array_size = window * sizeof(struct unpacked);
1393         struct unpacked *array;
1394         unsigned long mem_usage = 0;
1395
1396         array = xmalloc(array_size);
1397         memset(array, 0, array_size);
1398
1399         for (;;) {
1400                 struct object_entry *entry = *list++;
1401                 struct unpacked *n = array + idx;
1402                 int j, max_depth, best_base = -1;
1403
1404                 progress_lock();
1405                 if (!*list_size) {
1406                         progress_unlock();
1407                         break;
1408                 }
1409                 (*list_size)--;
1410                 if (!entry->preferred_base) {
1411                         (*processed)++;
1412                         display_progress(progress_state, *processed);
1413                 }
1414                 progress_unlock();
1415
1416                 mem_usage -= free_unpacked(n);
1417                 n->entry = entry;
1418
1419                 while (window_memory_limit &&
1420                        mem_usage > window_memory_limit &&
1421                        count > 1) {
1422                         uint32_t tail = (idx + window - count) % window;
1423                         mem_usage -= free_unpacked(array + tail);
1424                         count--;
1425                 }
1426
1427                 /* We do not compute delta to *create* objects we are not
1428                  * going to pack.
1429                  */
1430                 if (entry->preferred_base)
1431                         goto next;
1432
1433                 /*
1434                  * If the current object is at pack edge, take the depth the
1435                  * objects that depend on the current object into account
1436                  * otherwise they would become too deep.
1437                  */
1438                 max_depth = depth;
1439                 if (entry->delta_child) {
1440                         max_depth -= check_delta_limit(entry, 0);
1441                         if (max_depth <= 0)
1442                                 goto next;
1443                 }
1444
1445                 j = window;
1446                 while (--j > 0) {
1447                         int ret;
1448                         uint32_t other_idx = idx + j;
1449                         struct unpacked *m;
1450                         if (other_idx >= window)
1451                                 other_idx -= window;
1452                         m = array + other_idx;
1453                         if (!m->entry)
1454                                 break;
1455                         ret = try_delta(n, m, max_depth, &mem_usage);
1456                         if (ret < 0)
1457                                 break;
1458                         else if (ret > 0)
1459                                 best_base = other_idx;
1460                 }
1461
1462                 /*
1463                  * If we decided to cache the delta data, then it is best
1464                  * to compress it right away.  First because we have to do
1465                  * it anyway, and doing it here while we're threaded will
1466                  * save a lot of time in the non threaded write phase,
1467                  * as well as allow for caching more deltas within
1468                  * the same cache size limit.
1469                  * ...
1470                  * But only if not writing to stdout, since in that case
1471                  * the network is most likely throttling writes anyway,
1472                  * and therefore it is best to go to the write phase ASAP
1473                  * instead, as we can afford spending more time compressing
1474                  * between writes at that moment.
1475                  */
1476                 if (entry->delta_data && !pack_to_stdout) {
1477                         entry->z_delta_size = do_compress(&entry->delta_data,
1478                                                           entry->delta_size);
1479                         cache_lock();
1480                         delta_cache_size -= entry->delta_size;
1481                         delta_cache_size += entry->z_delta_size;
1482                         cache_unlock();
1483                 }
1484
1485                 /* if we made n a delta, and if n is already at max
1486                  * depth, leaving it in the window is pointless.  we
1487                  * should evict it first.
1488                  */
1489                 if (entry->delta && max_depth <= n->depth)
1490                         continue;
1491
1492                 /*
1493                  * Move the best delta base up in the window, after the
1494                  * currently deltified object, to keep it longer.  It will
1495                  * be the first base object to be attempted next.
1496                  */
1497                 if (entry->delta) {
1498                         struct unpacked swap = array[best_base];
1499                         int dist = (window + idx - best_base) % window;
1500                         int dst = best_base;
1501                         while (dist--) {
1502                                 int src = (dst + 1) % window;
1503                                 array[dst] = array[src];
1504                                 dst = src;
1505                         }
1506                         array[dst] = swap;
1507                 }
1508
1509                 next:
1510                 idx++;
1511                 if (count + 1 < window)
1512                         count++;
1513                 if (idx >= window)
1514                         idx = 0;
1515         }
1516
1517         for (i = 0; i < window; ++i) {
1518                 free_delta_index(array[i].index);
1519                 free(array[i].data);
1520         }
1521         free(array);
1522 }
1523
1524 #ifdef THREADED_DELTA_SEARCH
1525
1526 /*
1527  * The main thread waits on the condition that (at least) one of the workers
1528  * has stopped working (which is indicated in the .working member of
1529  * struct thread_params).
1530  * When a work thread has completed its work, it sets .working to 0 and
1531  * signals the main thread and waits on the condition that .data_ready
1532  * becomes 1.
1533  */
1534
1535 struct thread_params {
1536         pthread_t thread;
1537         struct object_entry **list;
1538         unsigned list_size;
1539         unsigned remaining;
1540         int window;
1541         int depth;
1542         int working;
1543         int data_ready;
1544         pthread_mutex_t mutex;
1545         pthread_cond_t cond;
1546         unsigned *processed;
1547 };
1548
1549 static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
1550
1551 static void *threaded_find_deltas(void *arg)
1552 {
1553         struct thread_params *me = arg;
1554
1555         while (me->remaining) {
1556                 find_deltas(me->list, &me->remaining,
1557                             me->window, me->depth, me->processed);
1558
1559                 progress_lock();
1560                 me->working = 0;
1561                 pthread_cond_signal(&progress_cond);
1562                 progress_unlock();
1563
1564                 /*
1565                  * We must not set ->data_ready before we wait on the
1566                  * condition because the main thread may have set it to 1
1567                  * before we get here. In order to be sure that new
1568                  * work is available if we see 1 in ->data_ready, it
1569                  * was initialized to 0 before this thread was spawned
1570                  * and we reset it to 0 right away.
1571                  */
1572                 pthread_mutex_lock(&me->mutex);
1573                 while (!me->data_ready)
1574                         pthread_cond_wait(&me->cond, &me->mutex);
1575                 me->data_ready = 0;
1576                 pthread_mutex_unlock(&me->mutex);
1577         }
1578         /* leave ->working 1 so that this doesn't get more work assigned */
1579         return NULL;
1580 }
1581
1582 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1583                            int window, int depth, unsigned *processed)
1584 {
1585         struct thread_params p[delta_search_threads];
1586         int i, ret, active_threads = 0;
1587
1588         if (delta_search_threads <= 1) {
1589                 find_deltas(list, &list_size, window, depth, processed);
1590                 return;
1591         }
1592
1593         /* Partition the work amongst work threads. */
1594         for (i = 0; i < delta_search_threads; i++) {
1595                 unsigned sub_size = list_size / (delta_search_threads - i);
1596
1597                 p[i].window = window;
1598                 p[i].depth = depth;
1599                 p[i].processed = processed;
1600                 p[i].working = 1;
1601                 p[i].data_ready = 0;
1602
1603                 /* try to split chunks on "path" boundaries */
1604                 while (sub_size && sub_size < list_size &&
1605                        list[sub_size]->hash &&
1606                        list[sub_size]->hash == list[sub_size-1]->hash)
1607                         sub_size++;
1608
1609                 p[i].list = list;
1610                 p[i].list_size = sub_size;
1611                 p[i].remaining = sub_size;
1612
1613                 list += sub_size;
1614                 list_size -= sub_size;
1615         }
1616
1617         /* Start work threads. */
1618         for (i = 0; i < delta_search_threads; i++) {
1619                 if (!p[i].list_size)
1620                         continue;
1621                 pthread_mutex_init(&p[i].mutex, NULL);
1622                 pthread_cond_init(&p[i].cond, NULL);
1623                 ret = pthread_create(&p[i].thread, NULL,
1624                                      threaded_find_deltas, &p[i]);
1625                 if (ret)
1626                         die("unable to create thread: %s", strerror(ret));
1627                 active_threads++;
1628         }
1629
1630         /*
1631          * Now let's wait for work completion.  Each time a thread is done
1632          * with its work, we steal half of the remaining work from the
1633          * thread with the largest number of unprocessed objects and give
1634          * it to that newly idle thread.  This ensure good load balancing
1635          * until the remaining object list segments are simply too short
1636          * to be worth splitting anymore.
1637          */
1638         while (active_threads) {
1639                 struct thread_params *target = NULL;
1640                 struct thread_params *victim = NULL;
1641                 unsigned sub_size = 0;
1642
1643                 progress_lock();
1644                 for (;;) {
1645                         for (i = 0; !target && i < delta_search_threads; i++)
1646                                 if (!p[i].working)
1647                                         target = &p[i];
1648                         if (target)
1649                                 break;
1650                         pthread_cond_wait(&progress_cond, &progress_mutex);
1651                 }
1652
1653                 for (i = 0; i < delta_search_threads; i++)
1654                         if (p[i].remaining > 2*window &&
1655                             (!victim || victim->remaining < p[i].remaining))
1656                                 victim = &p[i];
1657                 if (victim) {
1658                         sub_size = victim->remaining / 2;
1659                         list = victim->list + victim->list_size - sub_size;
1660                         while (sub_size && list[0]->hash &&
1661                                list[0]->hash == list[-1]->hash) {
1662                                 list++;
1663                                 sub_size--;
1664                         }
1665                         if (!sub_size) {
1666                                 /*
1667                                  * It is possible for some "paths" to have
1668                                  * so many objects that no hash boundary
1669                                  * might be found.  Let's just steal the
1670                                  * exact half in that case.
1671                                  */
1672                                 sub_size = victim->remaining / 2;
1673                                 list -= sub_size;
1674                         }
1675                         target->list = list;
1676                         victim->list_size -= sub_size;
1677                         victim->remaining -= sub_size;
1678                 }
1679                 target->list_size = sub_size;
1680                 target->remaining = sub_size;
1681                 target->working = 1;
1682                 progress_unlock();
1683
1684                 pthread_mutex_lock(&target->mutex);
1685                 target->data_ready = 1;
1686                 pthread_cond_signal(&target->cond);
1687                 pthread_mutex_unlock(&target->mutex);
1688
1689                 if (!sub_size) {
1690                         pthread_join(target->thread, NULL);
1691                         pthread_cond_destroy(&target->cond);
1692                         pthread_mutex_destroy(&target->mutex);
1693                         active_threads--;
1694                 }
1695         }
1696 }
1697
1698 #else
1699 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1700 #endif
1701
1702 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1703 {
1704         unsigned char peeled[20];
1705
1706         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1707             !peel_ref(path, peeled)        && /* peelable? */
1708             !is_null_sha1(peeled)          && /* annotated tag? */
1709             locate_object_entry(peeled))      /* object packed? */
1710                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1711         return 0;
1712 }
1713
1714 static void prepare_pack(int window, int depth)
1715 {
1716         struct object_entry **delta_list;
1717         uint32_t i, n, nr_deltas;
1718
1719         get_object_details();
1720
1721         if (!nr_objects || !window || !depth)
1722                 return;
1723
1724         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1725         nr_deltas = n = 0;
1726
1727         for (i = 0; i < nr_objects; i++) {
1728                 struct object_entry *entry = objects + i;
1729
1730                 if (entry->delta)
1731                         /* This happens if we decided to reuse existing
1732                          * delta from a pack.  "reuse_delta &&" is implied.
1733                          */
1734                         continue;
1735
1736                 if (entry->size < 50)
1737                         continue;
1738
1739                 if (entry->no_try_delta)
1740                         continue;
1741
1742                 if (!entry->preferred_base)
1743                         nr_deltas++;
1744
1745                 delta_list[n++] = entry;
1746         }
1747
1748         if (nr_deltas && n > 1) {
1749                 unsigned nr_done = 0;
1750                 if (progress)
1751                         progress_state = start_progress("Compressing objects",
1752                                                         nr_deltas);
1753                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1754                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1755                 stop_progress(&progress_state);
1756                 if (nr_done != nr_deltas)
1757                         die("inconsistency with delta count");
1758         }
1759         free(delta_list);
1760 }
1761
1762 static int git_pack_config(const char *k, const char *v)
1763 {
1764         if(!strcmp(k, "pack.window")) {
1765                 window = git_config_int(k, v);
1766                 return 0;
1767         }
1768         if (!strcmp(k, "pack.windowmemory")) {
1769                 window_memory_limit = git_config_ulong(k, v);
1770                 return 0;
1771         }
1772         if (!strcmp(k, "pack.depth")) {
1773                 depth = git_config_int(k, v);
1774                 return 0;
1775         }
1776         if (!strcmp(k, "pack.compression")) {
1777                 int level = git_config_int(k, v);
1778                 if (level == -1)
1779                         level = Z_DEFAULT_COMPRESSION;
1780                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1781                         die("bad pack compression level %d", level);
1782                 pack_compression_level = level;
1783                 pack_compression_seen = 1;
1784                 return 0;
1785         }
1786         if (!strcmp(k, "pack.deltacachesize")) {
1787                 max_delta_cache_size = git_config_int(k, v);
1788                 return 0;
1789         }
1790         if (!strcmp(k, "pack.deltacachelimit")) {
1791                 cache_max_small_delta_size = git_config_int(k, v);
1792                 return 0;
1793         }
1794         if (!strcmp(k, "pack.threads")) {
1795                 delta_search_threads = git_config_int(k, v);
1796                 if (delta_search_threads < 0)
1797                         die("invalid number of threads specified (%d)",
1798                             delta_search_threads);
1799 #ifndef THREADED_DELTA_SEARCH
1800                 if (delta_search_threads != 1)
1801                         warning("no threads support, ignoring %s", k);
1802 #endif
1803                 return 0;
1804         }
1805         if (!strcmp(k, "pack.indexversion")) {
1806                 pack_idx_default_version = git_config_int(k, v);
1807                 if (pack_idx_default_version > 2)
1808                         die("bad pack.indexversion=%d", pack_idx_default_version);
1809                 return 0;
1810         }
1811         if (!strcmp(k, "pack.packsizelimit")) {
1812                 pack_size_limit_cfg = git_config_ulong(k, v);
1813                 return 0;
1814         }
1815         return git_default_config(k, v);
1816 }
1817
1818 static void read_object_list_from_stdin(void)
1819 {
1820         char line[40 + 1 + PATH_MAX + 2];
1821         unsigned char sha1[20];
1822
1823         for (;;) {
1824                 if (!fgets(line, sizeof(line), stdin)) {
1825                         if (feof(stdin))
1826                                 break;
1827                         if (!ferror(stdin))
1828                                 die("fgets returned NULL, not EOF, not error!");
1829                         if (errno != EINTR)
1830                                 die("fgets: %s", strerror(errno));
1831                         clearerr(stdin);
1832                         continue;
1833                 }
1834                 if (line[0] == '-') {
1835                         if (get_sha1_hex(line+1, sha1))
1836                                 die("expected edge sha1, got garbage:\n %s",
1837                                     line);
1838                         add_preferred_base(sha1);
1839                         continue;
1840                 }
1841                 if (get_sha1_hex(line, sha1))
1842                         die("expected sha1, got garbage:\n %s", line);
1843
1844                 add_preferred_base_object(line+41);
1845                 add_object_entry(sha1, 0, line+41, 0);
1846         }
1847 }
1848
1849 #define OBJECT_ADDED (1u<<20)
1850
1851 static void show_commit(struct commit *commit)
1852 {
1853         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1854         commit->object.flags |= OBJECT_ADDED;
1855 }
1856
1857 static void show_object(struct object_array_entry *p)
1858 {
1859         add_preferred_base_object(p->name);
1860         add_object_entry(p->item->sha1, p->item->type, p->name, 0);
1861         p->item->flags |= OBJECT_ADDED;
1862 }
1863
1864 static void show_edge(struct commit *commit)
1865 {
1866         add_preferred_base(commit->object.sha1);
1867 }
1868
1869 struct in_pack_object {
1870         off_t offset;
1871         struct object *object;
1872 };
1873
1874 struct in_pack {
1875         int alloc;
1876         int nr;
1877         struct in_pack_object *array;
1878 };
1879
1880 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1881 {
1882         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1883         in_pack->array[in_pack->nr].object = object;
1884         in_pack->nr++;
1885 }
1886
1887 /*
1888  * Compare the objects in the offset order, in order to emulate the
1889  * "git-rev-list --objects" output that produced the pack originally.
1890  */
1891 static int ofscmp(const void *a_, const void *b_)
1892 {
1893         struct in_pack_object *a = (struct in_pack_object *)a_;
1894         struct in_pack_object *b = (struct in_pack_object *)b_;
1895
1896         if (a->offset < b->offset)
1897                 return -1;
1898         else if (a->offset > b->offset)
1899                 return 1;
1900         else
1901                 return hashcmp(a->object->sha1, b->object->sha1);
1902 }
1903
1904 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1905 {
1906         struct packed_git *p;
1907         struct in_pack in_pack;
1908         uint32_t i;
1909
1910         memset(&in_pack, 0, sizeof(in_pack));
1911
1912         for (p = packed_git; p; p = p->next) {
1913                 const unsigned char *sha1;
1914                 struct object *o;
1915
1916                 for (i = 0; i < revs->num_ignore_packed; i++) {
1917                         if (matches_pack_name(p, revs->ignore_packed[i]))
1918                                 break;
1919                 }
1920                 if (revs->num_ignore_packed <= i)
1921                         continue;
1922                 if (open_pack_index(p))
1923                         die("cannot open pack index");
1924
1925                 ALLOC_GROW(in_pack.array,
1926                            in_pack.nr + p->num_objects,
1927                            in_pack.alloc);
1928
1929                 for (i = 0; i < p->num_objects; i++) {
1930                         sha1 = nth_packed_object_sha1(p, i);
1931                         o = lookup_unknown_object(sha1);
1932                         if (!(o->flags & OBJECT_ADDED))
1933                                 mark_in_pack_object(o, p, &in_pack);
1934                         o->flags |= OBJECT_ADDED;
1935                 }
1936         }
1937
1938         if (in_pack.nr) {
1939                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
1940                       ofscmp);
1941                 for (i = 0; i < in_pack.nr; i++) {
1942                         struct object *o = in_pack.array[i].object;
1943                         add_object_entry(o->sha1, o->type, "", 0);
1944                 }
1945         }
1946         free(in_pack.array);
1947 }
1948
1949 static void get_object_list(int ac, const char **av)
1950 {
1951         struct rev_info revs;
1952         char line[1000];
1953         int flags = 0;
1954
1955         init_revisions(&revs, NULL);
1956         save_commit_buffer = 0;
1957         setup_revisions(ac, av, &revs, NULL);
1958
1959         while (fgets(line, sizeof(line), stdin) != NULL) {
1960                 int len = strlen(line);
1961                 if (len && line[len - 1] == '\n')
1962                         line[--len] = 0;
1963                 if (!len)
1964                         break;
1965                 if (*line == '-') {
1966                         if (!strcmp(line, "--not")) {
1967                                 flags ^= UNINTERESTING;
1968                                 continue;
1969                         }
1970                         die("not a rev '%s'", line);
1971                 }
1972                 if (handle_revision_arg(line, &revs, flags, 1))
1973                         die("bad revision '%s'", line);
1974         }
1975
1976         if (prepare_revision_walk(&revs))
1977                 die("revision walk setup failed");
1978         mark_edges_uninteresting(revs.commits, &revs, show_edge);
1979         traverse_commit_list(&revs, show_commit, show_object);
1980
1981         if (keep_unreachable)
1982                 add_objects_in_unpacked_packs(&revs);
1983 }
1984
1985 static int adjust_perm(const char *path, mode_t mode)
1986 {
1987         if (chmod(path, mode))
1988                 return -1;
1989         return adjust_shared_perm(path);
1990 }
1991
1992 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
1993 {
1994         int use_internal_rev_list = 0;
1995         int thin = 0;
1996         uint32_t i;
1997         const char **rp_av;
1998         int rp_ac_alloc = 64;
1999         int rp_ac;
2000
2001         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2002
2003         rp_av[0] = "pack-objects";
2004         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2005         rp_ac = 2;
2006
2007         git_config(git_pack_config);
2008         if (!pack_compression_seen && core_compression_seen)
2009                 pack_compression_level = core_compression_level;
2010
2011         progress = isatty(2);
2012         for (i = 1; i < argc; i++) {
2013                 const char *arg = argv[i];
2014
2015                 if (*arg != '-')
2016                         break;
2017
2018                 if (!strcmp("--non-empty", arg)) {
2019                         non_empty = 1;
2020                         continue;
2021                 }
2022                 if (!strcmp("--local", arg)) {
2023                         local = 1;
2024                         continue;
2025                 }
2026                 if (!strcmp("--incremental", arg)) {
2027                         incremental = 1;
2028                         continue;
2029                 }
2030                 if (!prefixcmp(arg, "--compression=")) {
2031                         char *end;
2032                         int level = strtoul(arg+14, &end, 0);
2033                         if (!arg[14] || *end)
2034                                 usage(pack_usage);
2035                         if (level == -1)
2036                                 level = Z_DEFAULT_COMPRESSION;
2037                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2038                                 die("bad pack compression level %d", level);
2039                         pack_compression_level = level;
2040                         continue;
2041                 }
2042                 if (!prefixcmp(arg, "--max-pack-size=")) {
2043                         char *end;
2044                         pack_size_limit_cfg = 0;
2045                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2046                         if (!arg[16] || *end)
2047                                 usage(pack_usage);
2048                         continue;
2049                 }
2050                 if (!prefixcmp(arg, "--window=")) {
2051                         char *end;
2052                         window = strtoul(arg+9, &end, 0);
2053                         if (!arg[9] || *end)
2054                                 usage(pack_usage);
2055                         continue;
2056                 }
2057                 if (!prefixcmp(arg, "--window-memory=")) {
2058                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2059                                 usage(pack_usage);
2060                         continue;
2061                 }
2062                 if (!prefixcmp(arg, "--threads=")) {
2063                         char *end;
2064                         delta_search_threads = strtoul(arg+10, &end, 0);
2065                         if (!arg[10] || *end || delta_search_threads < 0)
2066                                 usage(pack_usage);
2067 #ifndef THREADED_DELTA_SEARCH
2068                         if (delta_search_threads != 1)
2069                                 warning("no threads support, "
2070                                         "ignoring %s", arg);
2071 #endif
2072                         continue;
2073                 }
2074                 if (!prefixcmp(arg, "--depth=")) {
2075                         char *end;
2076                         depth = strtoul(arg+8, &end, 0);
2077                         if (!arg[8] || *end)
2078                                 usage(pack_usage);
2079                         continue;
2080                 }
2081                 if (!strcmp("--progress", arg)) {
2082                         progress = 1;
2083                         continue;
2084                 }
2085                 if (!strcmp("--all-progress", arg)) {
2086                         progress = 2;
2087                         continue;
2088                 }
2089                 if (!strcmp("-q", arg)) {
2090                         progress = 0;
2091                         continue;
2092                 }
2093                 if (!strcmp("--no-reuse-delta", arg)) {
2094                         reuse_delta = 0;
2095                         continue;
2096                 }
2097                 if (!strcmp("--no-reuse-object", arg)) {
2098                         reuse_object = reuse_delta = 0;
2099                         continue;
2100                 }
2101                 if (!strcmp("--delta-base-offset", arg)) {
2102                         allow_ofs_delta = 1;
2103                         continue;
2104                 }
2105                 if (!strcmp("--stdout", arg)) {
2106                         pack_to_stdout = 1;
2107                         continue;
2108                 }
2109                 if (!strcmp("--revs", arg)) {
2110                         use_internal_rev_list = 1;
2111                         continue;
2112                 }
2113                 if (!strcmp("--keep-unreachable", arg)) {
2114                         keep_unreachable = 1;
2115                         continue;
2116                 }
2117                 if (!strcmp("--include-tag", arg)) {
2118                         include_tag = 1;
2119                         continue;
2120                 }
2121                 if (!strcmp("--unpacked", arg) ||
2122                     !prefixcmp(arg, "--unpacked=") ||
2123                     !strcmp("--reflog", arg) ||
2124                     !strcmp("--all", arg)) {
2125                         use_internal_rev_list = 1;
2126                         if (rp_ac >= rp_ac_alloc - 1) {
2127                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2128                                 rp_av = xrealloc(rp_av,
2129                                                  rp_ac_alloc * sizeof(*rp_av));
2130                         }
2131                         rp_av[rp_ac++] = arg;
2132                         continue;
2133                 }
2134                 if (!strcmp("--thin", arg)) {
2135                         use_internal_rev_list = 1;
2136                         thin = 1;
2137                         rp_av[1] = "--objects-edge";
2138                         continue;
2139                 }
2140                 if (!prefixcmp(arg, "--index-version=")) {
2141                         char *c;
2142                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2143                         if (pack_idx_default_version > 2)
2144                                 die("bad %s", arg);
2145                         if (*c == ',')
2146                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2147                         if (*c || pack_idx_off32_limit & 0x80000000)
2148                                 die("bad %s", arg);
2149                         continue;
2150                 }
2151                 usage(pack_usage);
2152         }
2153
2154         /* Traditionally "pack-objects [options] base extra" failed;
2155          * we would however want to take refs parameter that would
2156          * have been given to upstream rev-list ourselves, which means
2157          * we somehow want to say what the base name is.  So the
2158          * syntax would be:
2159          *
2160          * pack-objects [options] base <refs...>
2161          *
2162          * in other words, we would treat the first non-option as the
2163          * base_name and send everything else to the internal revision
2164          * walker.
2165          */
2166
2167         if (!pack_to_stdout)
2168                 base_name = argv[i++];
2169
2170         if (pack_to_stdout != !base_name)
2171                 usage(pack_usage);
2172
2173         if (!pack_to_stdout && !pack_size_limit)
2174                 pack_size_limit = pack_size_limit_cfg;
2175
2176         if (pack_to_stdout && pack_size_limit)
2177                 die("--max-pack-size cannot be used to build a pack for transfer.");
2178
2179         if (!pack_to_stdout && thin)
2180                 die("--thin cannot be used to build an indexable pack.");
2181
2182 #ifdef THREADED_DELTA_SEARCH
2183         if (!delta_search_threads)      /* --threads=0 means autodetect */
2184                 delta_search_threads = online_cpus();
2185 #endif
2186
2187         prepare_packed_git();
2188
2189         if (progress)
2190                 progress_state = start_progress("Counting objects", 0);
2191         if (!use_internal_rev_list)
2192                 read_object_list_from_stdin();
2193         else {
2194                 rp_av[rp_ac] = NULL;
2195                 get_object_list(rp_ac, rp_av);
2196         }
2197         if (include_tag && nr_result)
2198                 for_each_ref(add_ref_tag, NULL);
2199         stop_progress(&progress_state);
2200
2201         if (non_empty && !nr_result)
2202                 return 0;
2203         if (nr_result)
2204                 prepare_pack(window, depth);
2205         write_pack_file();
2206         if (progress)
2207                 fprintf(stderr, "Total %u (delta %u), reused %u (delta %u)\n",
2208                         written, written_delta, reused, reused_delta);
2209         return 0;
2210 }