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

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "attr.h"
   4 #include "object.h"
   5 #include "blob.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "tree.h"
   9 #include "delta.h"
  10 #include "pack.h"
  11 #include "pack-revindex.h"
  12 #include "csum-file.h"
  13 #include "tree-walk.h"
  14 #include "diff.h"
  15 #include "revision.h"
  16 #include "list-objects.h"
  17 #include "progress.h"
  18 #include "refs.h"
  19
  20 #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 ignore_packed_keep;
  75 static int allow_ofs_delta;
  76 static const char *base_name;
  77 static int progress = 1;
  78 static int window = 10;
  79 static uint32_t pack_size_limit, pack_size_limit_cfg;
  80 static int depth = 50;
  81 static int delta_search_threads = 1;
  82 static int pack_to_stdout;
  83 static int num_preferred_base;
  84 static struct progress *progress_state;
  85 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  86 static int pack_compression_seen;
  87
  88 static unsigned long delta_cache_size = 0;
  89 static unsigned long max_delta_cache_size = 0;
  90 static unsigned long cache_max_small_delta_size = 1000;
  91
  92 static unsigned long window_memory_limit = 0;
  93
  94 /*
  95  * The object names in objects array are hashed with this hashtable,
  96  * to help looking up the entry by object name.
  97  * This hashtable is built after all the objects are seen.
  98  */
  99 static int *object_ix;
 100 static int object_ix_hashsz;
 101
 102 /*
 103  * stats
 104  */
 105 static uint32_t written, written_delta;
 106 static uint32_t reused, reused_delta;
 107
 108
 109 static void *get_delta(struct object_entry *entry)
 110 {
 111         unsigned long size, base_size, delta_size;
 112         void *buf, *base_buf, *delta_buf;
 113         enum object_type type;
 114
 115         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 116         if (!buf)
 117                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 118         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
 119         if (!base_buf)
 120                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 121         delta_buf = diff_delta(base_buf, base_size,
 122                                buf, size, &delta_size, 0);
 123         if (!delta_buf || delta_size != entry->delta_size)
 124                 die("delta size changed");
 125         free(buf);
 126         free(base_buf);
 127         return delta_buf;
 128 }
 129
 130 static unsigned long do_compress(void **pptr, unsigned long size)
 131 {
 132         z_stream stream;
 133         void *in, *out;
 134         unsigned long maxsize;
 135
 136         memset(&stream, 0, sizeof(stream));
 137         deflateInit(&stream, pack_compression_level);
 138         maxsize = deflateBound(&stream, size);
 139
 140         in = *pptr;
 141         out = xmalloc(maxsize);
 142         *pptr = out;
 143
 144         stream.next_in = in;
 145         stream.avail_in = size;
 146         stream.next_out = out;
 147         stream.avail_out = maxsize;
 148         while (deflate(&stream, Z_FINISH) == Z_OK)
 149                 ; /* nothing */
 150         deflateEnd(&stream);
 151
 152         free(in);
 153         return stream.total_out;
 154 }
 155
 156 /*
 157  * The per-object header is a pretty dense thing, which is
 158  *  - first byte: low four bits are "size", then three bits of "type",
 159  *    and the high bit is "size continues".
 160  *  - each byte afterwards: low seven bits are size continuation,
 161  *    with the high bit being "size continues"
 162  */
 163 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 164 {
 165         int n = 1;
 166         unsigned char c;
 167
 168         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 169                 die("bad type %d", type);
 170
 171         c = (type << 4) | (size & 15);
 172         size >>= 4;
 173         while (size) {
 174                 *hdr++ = c | 0x80;
 175                 c = size & 0x7f;
 176                 size >>= 7;
 177                 n++;
 178         }
 179         *hdr = c;
 180         return n;
 181 }
 182
 183 /*
 184  * we are going to reuse the existing object data as is.  make
 185  * sure it is not corrupt.
 186  */
 187 static int check_pack_inflate(struct packed_git *p,
 188                 struct pack_window **w_curs,
 189                 off_t offset,
 190                 off_t len,
 191                 unsigned long expect)
 192 {
 193         z_stream stream;
 194         unsigned char fakebuf[4096], *in;
 195         int st;
 196
 197         memset(&stream, 0, sizeof(stream));
 198         inflateInit(&stream);
 199         do {
 200                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 201                 stream.next_in = in;
 202                 stream.next_out = fakebuf;
 203                 stream.avail_out = sizeof(fakebuf);
 204                 st = inflate(&stream, Z_FINISH);
 205                 offset += stream.next_in - in;
 206         } while (st == Z_OK || st == Z_BUF_ERROR);
 207         inflateEnd(&stream);
 208         return (st == Z_STREAM_END &&
 209                 stream.total_out == expect &&
 210                 stream.total_in == len) ? 0 : -1;
 211 }
 212
 213 static void copy_pack_data(struct sha1file *f,
 214                 struct packed_git *p,
 215                 struct pack_window **w_curs,
 216                 off_t offset,
 217                 off_t len)
 218 {
 219         unsigned char *in;
 220         unsigned int avail;
 221
 222         while (len) {
 223                 in = use_pack(p, w_curs, offset, &avail);
 224                 if (avail > len)
 225                         avail = (unsigned int)len;
 226                 sha1write(f, in, avail);
 227                 offset += avail;
 228                 len -= avail;
 229         }
 230 }
 231
 232 static unsigned long write_object(struct sha1file *f,
 233                                   struct object_entry *entry,
 234                                   off_t write_offset)
 235 {
 236         unsigned long size, limit, datalen;
 237         void *buf;
 238         unsigned char header[10], dheader[10];
 239         unsigned hdrlen;
 240         enum object_type type;
 241         int usable_delta, to_reuse;
 242
 243         if (!pack_to_stdout)
 244                 crc32_begin(f);
 245
 246         type = entry->type;
 247
 248         /* write limit if limited packsize and not first object */
 249         if (!pack_size_limit || !nr_written)
 250                 limit = 0;
 251         else if (pack_size_limit <= write_offset)
 252                 /*
 253                  * the earlier object did not fit the limit; avoid
 254                  * mistaking this with unlimited (i.e. limit = 0).
 255                  */
 256                 limit = 1;
 257         else
 258                 limit = pack_size_limit - write_offset;
 259
 260         if (!entry->delta)
 261                 usable_delta = 0;       /* no delta */
 262         else if (!pack_size_limit)
 263                usable_delta = 1;        /* unlimited packfile */
 264         else if (entry->delta->idx.offset == (off_t)-1)
 265                 usable_delta = 0;       /* base was written to another pack */
 266         else if (entry->delta->idx.offset)
 267                 usable_delta = 1;       /* base already exists in this pack */
 268         else
 269                 usable_delta = 0;       /* base could end up in another pack */
 270
 271         if (!reuse_object)
 272                 to_reuse = 0;   /* explicit */
 273         else if (!entry->in_pack)
 274                 to_reuse = 0;   /* can't reuse what we don't have */
 275         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
 276                                 /* check_object() decided it for us ... */
 277                 to_reuse = usable_delta;
 278                                 /* ... but pack split may override that */
 279         else if (type != entry->in_pack_type)
 280                 to_reuse = 0;   /* pack has delta which is unusable */
 281         else if (entry->delta)
 282                 to_reuse = 0;   /* we want to pack afresh */
 283         else
 284                 to_reuse = 1;   /* we have it in-pack undeltified,
 285                                  * and we do not need to deltify it.
 286                                  */
 287
 288         if (!to_reuse) {
 289                 if (!usable_delta) {
 290                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 291                         if (!buf)
 292                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 293                         /*
 294                          * make sure no cached delta data remains from a
 295                          * previous attempt before a pack split occured.
 296                          */
 297                         free(entry->delta_data);
 298                         entry->delta_data = NULL;
 299                         entry->z_delta_size = 0;
 300                 } else if (entry->delta_data) {
 301                         size = entry->delta_size;
 302                         buf = entry->delta_data;
 303                         entry->delta_data = NULL;
 304                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 305                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 306                 } else {
 307                         buf = get_delta(entry);
 308                         size = entry->delta_size;
 309                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 310                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 311                 }
 312
 313                 if (entry->z_delta_size)
 314                         datalen = entry->z_delta_size;
 315                 else
 316                         datalen = do_compress(&buf, size);
 317
 318                 /*
 319                  * The object header is a byte of 'type' followed by zero or
 320                  * more bytes of length.
 321                  */
 322                 hdrlen = encode_header(type, size, header);
 323
 324                 if (type == OBJ_OFS_DELTA) {
 325                         /*
 326                          * Deltas with relative base contain an additional
 327                          * encoding of the relative offset for the delta
 328                          * base from this object's position in the pack.
 329                          */
 330                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 331                         unsigned pos = sizeof(dheader) - 1;
 332                         dheader[pos] = ofs & 127;
 333                         while (ofs >>= 7)
 334                                 dheader[--pos] = 128 | (--ofs & 127);
 335                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 336                                 free(buf);
 337                                 return 0;
 338                         }
 339                         sha1write(f, header, hdrlen);
 340                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 341                         hdrlen += sizeof(dheader) - pos;
 342                 } else if (type == OBJ_REF_DELTA) {
 343                         /*
 344                          * Deltas with a base reference contain
 345                          * an additional 20 bytes for the base sha1.
 346                          */
 347                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 348                                 free(buf);
 349                                 return 0;
 350                         }
 351                         sha1write(f, header, hdrlen);
 352                         sha1write(f, entry->delta->idx.sha1, 20);
 353                         hdrlen += 20;
 354                 } else {
 355                         if (limit && hdrlen + datalen + 20 >= limit) {
 356                                 free(buf);
 357                                 return 0;
 358                         }
 359                         sha1write(f, header, hdrlen);
 360                 }
 361                 sha1write(f, buf, datalen);
 362                 free(buf);
 363         }
 364         else {
 365                 struct packed_git *p = entry->in_pack;
 366                 struct pack_window *w_curs = NULL;
 367                 struct revindex_entry *revidx;
 368                 off_t offset;
 369
 370                 if (entry->delta) {
 371                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 372                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 373                         reused_delta++;
 374                 }
 375                 hdrlen = encode_header(type, entry->size, header);
 376                 offset = entry->in_pack_offset;
 377                 revidx = find_pack_revindex(p, offset);
 378                 datalen = revidx[1].offset - offset;
 379                 if (!pack_to_stdout && p->index_version > 1 &&
 380                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
 381                         die("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 382                 offset += entry->in_pack_header_size;
 383                 datalen -= entry->in_pack_header_size;
 384                 if (type == OBJ_OFS_DELTA) {
 385                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 386                         unsigned pos = sizeof(dheader) - 1;
 387                         dheader[pos] = ofs & 127;
 388                         while (ofs >>= 7)
 389                                 dheader[--pos] = 128 | (--ofs & 127);
 390                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit)
 391                                 return 0;
 392                         sha1write(f, header, hdrlen);
 393                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 394                         hdrlen += sizeof(dheader) - pos;
 395                 } else if (type == OBJ_REF_DELTA) {
 396                         if (limit && hdrlen + 20 + datalen + 20 >= limit)
 397                                 return 0;
 398                         sha1write(f, header, hdrlen);
 399                         sha1write(f, entry->delta->idx.sha1, 20);
 400                         hdrlen += 20;
 401                 } else {
 402                         if (limit && hdrlen + datalen + 20 >= limit)
 403                                 return 0;
 404                         sha1write(f, header, hdrlen);
 405                 }
 406
 407                 if (!pack_to_stdout && p->index_version == 1 &&
 408                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
 409                         die("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 410                 copy_pack_data(f, p, &w_curs, offset, datalen);
 411                 unuse_pack(&w_curs);
 412                 reused++;
 413         }
 414         if (usable_delta)
 415                 written_delta++;
 416         written++;
 417         if (!pack_to_stdout)
 418                 entry->idx.crc32 = crc32_end(f);
 419         return hdrlen + datalen;
 420 }
 421
 422 static int write_one(struct sha1file *f,
 423                                struct object_entry *e,
 424                                off_t *offset)
 425 {
 426         unsigned long size;
 427
 428         /* offset is non zero if object is written already. */
 429         if (e->idx.offset || e->preferred_base)
 430                 return 1;
 431
 432         /* if we are deltified, write out base object first. */
 433         if (e->delta && !write_one(f, e->delta, offset))
 434                 return 0;
 435
 436         e->idx.offset = *offset;
 437         size = write_object(f, e, *offset);
 438         if (!size) {
 439                 e->idx.offset = 0;
 440                 return 0;
 441         }
 442         written_list[nr_written++] = &e->idx;
 443
 444         /* make sure off_t is sufficiently large not to wrap */
 445         if (*offset > *offset + size)
 446                 die("pack too large for current definition of off_t");
 447         *offset += size;
 448         return 1;
 449 }
 450
 451 /* forward declaration for write_pack_file */
 452 static int adjust_perm(const char *path, mode_t mode);
 453
 454 static void write_pack_file(void)
 455 {
 456         uint32_t i = 0, j;
 457         struct sha1file *f;
 458         off_t offset;
 459         struct pack_header hdr;
 460         uint32_t nr_remaining = nr_result;
 461         time_t last_mtime = 0;
 462
 463         if (progress > pack_to_stdout)
 464                 progress_state = start_progress("Writing objects", nr_result);
 465         written_list = xmalloc(nr_objects * sizeof(*written_list));
 466
 467         do {
 468                 unsigned char sha1[20];
 469                 char *pack_tmp_name = NULL;
 470
 471                 if (pack_to_stdout) {
 472                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 473                 } else {
 474                         char tmpname[PATH_MAX];
 475                         int fd;
 476                         snprintf(tmpname, sizeof(tmpname),
 477                                  "%s/pack/tmp_pack_XXXXXX", get_object_directory());
 478                         fd = xmkstemp(tmpname);
 479                         pack_tmp_name = xstrdup(tmpname);
 480                         f = sha1fd(fd, pack_tmp_name);
 481                 }
 482
 483                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
 484                 hdr.hdr_version = htonl(PACK_VERSION);
 485                 hdr.hdr_entries = htonl(nr_remaining);
 486                 sha1write(f, &hdr, sizeof(hdr));
 487                 offset = sizeof(hdr);
 488                 nr_written = 0;
 489                 for (; i < nr_objects; i++) {
 490                         if (!write_one(f, objects + i, &offset))
 491                                 break;
 492                         display_progress(progress_state, written);
 493                 }
 494
 495                 /*
 496                  * Did we write the wrong # entries in the header?
 497                  * If so, rewrite it like in fast-import
 498                  */
 499                 if (pack_to_stdout) {
 500                         sha1close(f, sha1, CSUM_CLOSE);
 501                 } else if (nr_written == nr_remaining) {
 502                         sha1close(f, sha1, CSUM_FSYNC);
 503                 } else {
 504                         int fd = sha1close(f, sha1, 0);
 505                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
 506                                                  nr_written, sha1, offset);
 507                         close(fd);
 508                 }
 509
 510                 if (!pack_to_stdout) {
 511                         mode_t mode = umask(0);
 512                         struct stat st;
 513                         char *idx_tmp_name, tmpname[PATH_MAX];
 514
 515                         umask(mode);
 516                         mode = 0444 & ~mode;
 517
 518                         idx_tmp_name = write_idx_file(NULL, written_list,
 519                                                       nr_written, sha1);
 520
 521                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 522                                  base_name, sha1_to_hex(sha1));
 523                         free_pack_by_name(tmpname);
 524                         if (adjust_perm(pack_tmp_name, mode))
 525                                 die("unable to make temporary pack file readable: %s",
 526                                     strerror(errno));
 527                         if (rename(pack_tmp_name, tmpname))
 528                                 die("unable to rename temporary pack file: %s",
 529                                     strerror(errno));
 530
 531                         /*
 532                          * Packs are runtime accessed in their mtime
 533                          * order since newer packs are more likely to contain
 534                          * younger objects.  So if we are creating multiple
 535                          * packs then we should modify the mtime of later ones
 536                          * to preserve this property.
 537                          */
 538                         if (stat(tmpname, &st) < 0) {
 539                                 warning("failed to stat %s: %s",
 540                                         tmpname, strerror(errno));
 541                         } else if (!last_mtime) {
 542                                 last_mtime = st.st_mtime;
 543                         } else {
 544                                 struct utimbuf utb;
 545                                 utb.actime = st.st_atime;
 546                                 utb.modtime = --last_mtime;
 547                                 if (utime(tmpname, &utb) < 0)
 548                                         warning("failed utime() on %s: %s",
 549                                                 tmpname, strerror(errno));
 550                         }
 551
 552                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 553                                  base_name, sha1_to_hex(sha1));
 554                         if (adjust_perm(idx_tmp_name, mode))
 555                                 die("unable to make temporary index file readable: %s",
 556                                     strerror(errno));
 557                         if (rename(idx_tmp_name, tmpname))
 558                                 die("unable to rename temporary index file: %s",
 559                                     strerror(errno));
 560
 561                         free(idx_tmp_name);
 562                         free(pack_tmp_name);
 563                         puts(sha1_to_hex(sha1));
 564                 }
 565
 566                 /* mark written objects as written to previous pack */
 567                 for (j = 0; j < nr_written; j++) {
 568                         written_list[j]->offset = (off_t)-1;
 569                 }
 570                 nr_remaining -= nr_written;
 571         } while (nr_remaining && i < nr_objects);
 572
 573         free(written_list);
 574         stop_progress(&progress_state);
 575         if (written != nr_result)
 576                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
 577                         written, nr_result);
 578         /*
 579          * We have scanned through [0 ... i).  Since we have written
 580          * the correct number of objects,  the remaining [i ... nr_objects)
 581          * items must be either already written (due to out-of-order delta base)
 582          * or a preferred base.  Count those which are neither and complain if any.
 583          */
 584         for (j = 0; i < nr_objects; i++) {
 585                 struct object_entry *e = objects + i;
 586                 j += !e->idx.offset && !e->preferred_base;
 587         }
 588         if (j)
 589                 die("wrote %"PRIu32" objects as expected but %"PRIu32
 590                         " unwritten", written, j);
 591 }
 592
 593 static int locate_object_entry_hash(const unsigned char *sha1)
 594 {
 595         int i;
 596         unsigned int ui;
 597         memcpy(&ui, sha1, sizeof(unsigned int));
 598         i = ui % object_ix_hashsz;
 599         while (0 < object_ix[i]) {
 600                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 601                         return i;
 602                 if (++i == object_ix_hashsz)
 603                         i = 0;
 604         }
 605         return -1 - i;
 606 }
 607
 608 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 609 {
 610         int i;
 611
 612         if (!object_ix_hashsz)
 613                 return NULL;
 614
 615         i = locate_object_entry_hash(sha1);
 616         if (0 <= i)
 617                 return &objects[object_ix[i]-1];
 618         return NULL;
 619 }
 620
 621 static void rehash_objects(void)
 622 {
 623         uint32_t i;
 624         struct object_entry *oe;
 625
 626         object_ix_hashsz = nr_objects * 3;
 627         if (object_ix_hashsz < 1024)
 628                 object_ix_hashsz = 1024;
 629         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 630         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 631         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 632                 int ix = locate_object_entry_hash(oe->idx.sha1);
 633                 if (0 <= ix)
 634                         continue;
 635                 ix = -1 - ix;
 636                 object_ix[ix] = i + 1;
 637         }
 638 }
 639
 640 static unsigned name_hash(const char *name)
 641 {
 642         unsigned char c;
 643         unsigned hash = 0;
 644
 645         if (!name)
 646                 return 0;
 647
 648         /*
 649          * This effectively just creates a sortable number from the
 650          * last sixteen non-whitespace characters. Last characters
 651          * count "most", so things that end in ".c" sort together.
 652          */
 653         while ((c = *name++) != 0) {
 654                 if (isspace(c))
 655                         continue;
 656                 hash = (hash >> 2) + (c << 24);
 657         }
 658         return hash;
 659 }
 660
 661 static void setup_delta_attr_check(struct git_attr_check *check)
 662 {
 663         static struct git_attr *attr_delta;
 664
 665         if (!attr_delta)
 666                 attr_delta = git_attr("delta", 5);
 667
 668         check[0].attr = attr_delta;
 669 }
 670
 671 static int no_try_delta(const char *path)
 672 {
 673         struct git_attr_check check[1];
 674
 675         setup_delta_attr_check(check);
 676         if (git_checkattr(path, ARRAY_SIZE(check), check))
 677                 return 0;
 678         if (ATTR_FALSE(check->value))
 679                 return 1;
 680         return 0;
 681 }
 682
 683 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 684                             const char *name, int exclude)
 685 {
 686         struct object_entry *entry;
 687         struct packed_git *p, *found_pack = NULL;
 688         off_t found_offset = 0;
 689         int ix;
 690         unsigned hash = name_hash(name);
 691
 692         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 693         if (ix >= 0) {
 694                 if (exclude) {
 695                         entry = objects + object_ix[ix] - 1;
 696                         if (!entry->preferred_base)
 697                                 nr_result--;
 698                         entry->preferred_base = 1;
 699                 }
 700                 return 0;
 701         }
 702
 703         if (!exclude && local && has_loose_object_nonlocal(sha1))
 704                 return 0;
 705
 706         for (p = packed_git; p; p = p->next) {
 707                 off_t offset = find_pack_entry_one(sha1, p);
 708                 if (offset) {
 709                         if (!found_pack) {
 710                                 found_offset = offset;
 711                                 found_pack = p;
 712                         }
 713                         if (exclude)
 714                                 break;
 715                         if (incremental)
 716                                 return 0;
 717                         if (local && !p->pack_local)
 718                                 return 0;
 719                         if (ignore_packed_keep && p->pack_local && p->pack_keep)
 720                                 return 0;
 721                 }
 722         }
 723
 724         if (nr_objects >= nr_alloc) {
 725                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 726                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 727         }
 728
 729         entry = objects + nr_objects++;
 730         memset(entry, 0, sizeof(*entry));
 731         hashcpy(entry->idx.sha1, sha1);
 732         entry->hash = hash;
 733         if (type)
 734                 entry->type = type;
 735         if (exclude)
 736                 entry->preferred_base = 1;
 737         else
 738                 nr_result++;
 739         if (found_pack) {
 740                 entry->in_pack = found_pack;
 741                 entry->in_pack_offset = found_offset;
 742         }
 743
 744         if (object_ix_hashsz * 3 <= nr_objects * 4)
 745                 rehash_objects();
 746         else
 747                 object_ix[-1 - ix] = nr_objects;
 748
 749         display_progress(progress_state, nr_objects);
 750
 751         if (name && no_try_delta(name))
 752                 entry->no_try_delta = 1;
 753
 754         return 1;
 755 }
 756
 757 struct pbase_tree_cache {
 758         unsigned char sha1[20];
 759         int ref;
 760         int temporary;
 761         void *tree_data;
 762         unsigned long tree_size;
 763 };
 764
 765 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 766 static int pbase_tree_cache_ix(const unsigned char *sha1)
 767 {
 768         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 769 }
 770 static int pbase_tree_cache_ix_incr(int ix)
 771 {
 772         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 773 }
 774
 775 static struct pbase_tree {
 776         struct pbase_tree *next;
 777         /* This is a phony "cache" entry; we are not
 778          * going to evict it nor find it through _get()
 779          * mechanism -- this is for the toplevel node that
 780          * would almost always change with any commit.
 781          */
 782         struct pbase_tree_cache pcache;
 783 } *pbase_tree;
 784
 785 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 786 {
 787         struct pbase_tree_cache *ent, *nent;
 788         void *data;
 789         unsigned long size;
 790         enum object_type type;
 791         int neigh;
 792         int my_ix = pbase_tree_cache_ix(sha1);
 793         int available_ix = -1;
 794
 795         /* pbase-tree-cache acts as a limited hashtable.
 796          * your object will be found at your index or within a few
 797          * slots after that slot if it is cached.
 798          */
 799         for (neigh = 0; neigh < 8; neigh++) {
 800                 ent = pbase_tree_cache[my_ix];
 801                 if (ent && !hashcmp(ent->sha1, sha1)) {
 802                         ent->ref++;
 803                         return ent;
 804                 }
 805                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 806                          ((0 <= available_ix) &&
 807                           (!ent && pbase_tree_cache[available_ix])))
 808                         available_ix = my_ix;
 809                 if (!ent)
 810                         break;
 811                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 812         }
 813
 814         /* Did not find one.  Either we got a bogus request or
 815          * we need to read and perhaps cache.
 816          */
 817         data = read_sha1_file(sha1, &type, &size);
 818         if (!data)
 819                 return NULL;
 820         if (type != OBJ_TREE) {
 821                 free(data);
 822                 return NULL;
 823         }
 824
 825         /* We need to either cache or return a throwaway copy */
 826
 827         if (available_ix < 0)
 828                 ent = NULL;
 829         else {
 830                 ent = pbase_tree_cache[available_ix];
 831                 my_ix = available_ix;
 832         }
 833
 834         if (!ent) {
 835                 nent = xmalloc(sizeof(*nent));
 836                 nent->temporary = (available_ix < 0);
 837         }
 838         else {
 839                 /* evict and reuse */
 840                 free(ent->tree_data);
 841                 nent = ent;
 842         }
 843         hashcpy(nent->sha1, sha1);
 844         nent->tree_data = data;
 845         nent->tree_size = size;
 846         nent->ref = 1;
 847         if (!nent->temporary)
 848                 pbase_tree_cache[my_ix] = nent;
 849         return nent;
 850 }
 851
 852 static void pbase_tree_put(struct pbase_tree_cache *cache)
 853 {
 854         if (!cache->temporary) {
 855                 cache->ref--;
 856                 return;
 857         }
 858         free(cache->tree_data);
 859         free(cache);
 860 }
 861
 862 static int name_cmp_len(const char *name)
 863 {
 864         int i;
 865         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 866                 ;
 867         return i;
 868 }
 869
 870 static void add_pbase_object(struct tree_desc *tree,
 871                              const char *name,
 872                              int cmplen,
 873                              const char *fullname)
 874 {
 875         struct name_entry entry;
 876         int cmp;
 877
 878         while (tree_entry(tree,&entry)) {
 879                 if (S_ISGITLINK(entry.mode))
 880                         continue;
 881                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 882                       memcmp(name, entry.path, cmplen);
 883                 if (cmp > 0)
 884                         continue;
 885                 if (cmp < 0)
 886                         return;
 887                 if (name[cmplen] != '/') {
 888                         add_object_entry(entry.sha1,
 889                                          object_type(entry.mode),
 890                                          fullname, 1);
 891                         return;
 892                 }
 893                 if (S_ISDIR(entry.mode)) {
 894                         struct tree_desc sub;
 895                         struct pbase_tree_cache *tree;
 896                         const char *down = name+cmplen+1;
 897                         int downlen = name_cmp_len(down);
 898
 899                         tree = pbase_tree_get(entry.sha1);
 900                         if (!tree)
 901                                 return;
 902                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 903
 904                         add_pbase_object(&sub, down, downlen, fullname);
 905                         pbase_tree_put(tree);
 906                 }
 907         }
 908 }
 909
 910 static unsigned *done_pbase_paths;
 911 static int done_pbase_paths_num;
 912 static int done_pbase_paths_alloc;
 913 static int done_pbase_path_pos(unsigned hash)
 914 {
 915         int lo = 0;
 916         int hi = done_pbase_paths_num;
 917         while (lo < hi) {
 918                 int mi = (hi + lo) / 2;
 919                 if (done_pbase_paths[mi] == hash)
 920                         return mi;
 921                 if (done_pbase_paths[mi] < hash)
 922                         hi = mi;
 923                 else
 924                         lo = mi + 1;
 925         }
 926         return -lo-1;
 927 }
 928
 929 static int check_pbase_path(unsigned hash)
 930 {
 931         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 932         if (0 <= pos)
 933                 return 1;
 934         pos = -pos - 1;
 935         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 936                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 937                 done_pbase_paths = xrealloc(done_pbase_paths,
 938                                             done_pbase_paths_alloc *
 939                                             sizeof(unsigned));
 940         }
 941         done_pbase_paths_num++;
 942         if (pos < done_pbase_paths_num)
 943                 memmove(done_pbase_paths + pos + 1,
 944                         done_pbase_paths + pos,
 945                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 946         done_pbase_paths[pos] = hash;
 947         return 0;
 948 }
 949
 950 static void add_preferred_base_object(const char *name)
 951 {
 952         struct pbase_tree *it;
 953         int cmplen;
 954         unsigned hash = name_hash(name);
 955
 956         if (!num_preferred_base || check_pbase_path(hash))
 957                 return;
 958
 959         cmplen = name_cmp_len(name);
 960         for (it = pbase_tree; it; it = it->next) {
 961                 if (cmplen == 0) {
 962                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 963                 }
 964                 else {
 965                         struct tree_desc tree;
 966                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 967                         add_pbase_object(&tree, name, cmplen, name);
 968                 }
 969         }
 970 }
 971
 972 static void add_preferred_base(unsigned char *sha1)
 973 {
 974         struct pbase_tree *it;
 975         void *data;
 976         unsigned long size;
 977         unsigned char tree_sha1[20];
 978
 979         if (window <= num_preferred_base++)
 980                 return;
 981
 982         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 983         if (!data)
 984                 return;
 985
 986         for (it = pbase_tree; it; it = it->next) {
 987                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 988                         free(data);
 989                         return;
 990                 }
 991         }
 992
 993         it = xcalloc(1, sizeof(*it));
 994         it->next = pbase_tree;
 995         pbase_tree = it;
 996
 997         hashcpy(it->pcache.sha1, tree_sha1);
 998         it->pcache.tree_data = data;
 999         it->pcache.tree_size = size;
1000 }
1001
1002 static void check_object(struct object_entry *entry)
1003 {
1004         if (entry->in_pack) {
1005                 struct packed_git *p = entry->in_pack;
1006                 struct pack_window *w_curs = NULL;
1007                 const unsigned char *base_ref = NULL;
1008                 struct object_entry *base_entry;
1009                 unsigned long used, used_0;
1010                 unsigned int avail;
1011                 off_t ofs;
1012                 unsigned char *buf, c;
1013
1014                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1015
1016                 /*
1017                  * We want in_pack_type even if we do not reuse delta
1018                  * since non-delta representations could still be reused.
1019                  */
1020                 used = unpack_object_header_gently(buf, avail,
1021                                                    &entry->in_pack_type,
1022                                                    &entry->size);
1023
1024                 /*
1025                  * Determine if this is a delta and if so whether we can
1026                  * reuse it or not.  Otherwise let's find out as cheaply as
1027                  * possible what the actual type and size for this object is.
1028                  */
1029                 switch (entry->in_pack_type) {
1030                 default:
1031                         /* Not a delta hence we've already got all we need. */
1032                         entry->type = entry->in_pack_type;
1033                         entry->in_pack_header_size = used;
1034                         unuse_pack(&w_curs);
1035                         return;
1036                 case OBJ_REF_DELTA:
1037                         if (reuse_delta && !entry->preferred_base)
1038                                 base_ref = use_pack(p, &w_curs,
1039                                                 entry->in_pack_offset + used, NULL);
1040                         entry->in_pack_header_size = used + 20;
1041                         break;
1042                 case OBJ_OFS_DELTA:
1043                         buf = use_pack(p, &w_curs,
1044                                        entry->in_pack_offset + used, NULL);
1045                         used_0 = 0;
1046                         c = buf[used_0++];
1047                         ofs = c & 127;
1048                         while (c & 128) {
1049                                 ofs += 1;
1050                                 if (!ofs || MSB(ofs, 7))
1051                                         die("delta base offset overflow in pack for %s",
1052                                             sha1_to_hex(entry->idx.sha1));
1053                                 c = buf[used_0++];
1054                                 ofs = (ofs << 7) + (c & 127);
1055                         }
1056                         if (ofs >= entry->in_pack_offset)
1057                                 die("delta base offset out of bound for %s",
1058                                     sha1_to_hex(entry->idx.sha1));
1059                         ofs = entry->in_pack_offset - ofs;
1060                         if (reuse_delta && !entry->preferred_base) {
1061                                 struct revindex_entry *revidx;
1062                                 revidx = find_pack_revindex(p, ofs);
1063                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1064                         }
1065                         entry->in_pack_header_size = used + used_0;
1066                         break;
1067                 }
1068
1069                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1070                         /*
1071                          * If base_ref was set above that means we wish to
1072                          * reuse delta data, and we even found that base
1073                          * in the list of objects we want to pack. Goodie!
1074                          *
1075                          * Depth value does not matter - find_deltas() will
1076                          * never consider reused delta as the base object to
1077                          * deltify other objects against, in order to avoid
1078                          * circular deltas.
1079                          */
1080                         entry->type = entry->in_pack_type;
1081                         entry->delta = base_entry;
1082                         entry->delta_sibling = base_entry->delta_child;
1083                         base_entry->delta_child = entry;
1084                         unuse_pack(&w_curs);
1085                         return;
1086                 }
1087
1088                 if (entry->type) {
1089                         /*
1090                          * This must be a delta and we already know what the
1091                          * final object type is.  Let's extract the actual
1092                          * object size from the delta header.
1093                          */
1094                         entry->size = get_size_from_delta(p, &w_curs,
1095                                         entry->in_pack_offset + entry->in_pack_header_size);
1096                         unuse_pack(&w_curs);
1097                         return;
1098                 }
1099
1100                 /*
1101                  * No choice but to fall back to the recursive delta walk
1102                  * with sha1_object_info() to find about the object type
1103                  * at this point...
1104                  */
1105                 unuse_pack(&w_curs);
1106         }
1107
1108         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1109         /*
1110          * The error condition is checked in prepare_pack().  This is
1111          * to permit a missing preferred base object to be ignored
1112          * as a preferred base.  Doing so can result in a larger
1113          * pack file, but the transfer will still take place.
1114          */
1115 }
1116
1117 static int pack_offset_sort(const void *_a, const void *_b)
1118 {
1119         const struct object_entry *a = *(struct object_entry **)_a;
1120         const struct object_entry *b = *(struct object_entry **)_b;
1121
1122         /* avoid filesystem trashing with loose objects */
1123         if (!a->in_pack && !b->in_pack)
1124                 return hashcmp(a->idx.sha1, b->idx.sha1);
1125
1126         if (a->in_pack < b->in_pack)
1127                 return -1;
1128         if (a->in_pack > b->in_pack)
1129                 return 1;
1130         return a->in_pack_offset < b->in_pack_offset ? -1 :
1131                         (a->in_pack_offset > b->in_pack_offset);
1132 }
1133
1134 static void get_object_details(void)
1135 {
1136         uint32_t i;
1137         struct object_entry **sorted_by_offset;
1138
1139         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1140         for (i = 0; i < nr_objects; i++)
1141                 sorted_by_offset[i] = objects + i;
1142         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1143
1144         for (i = 0; i < nr_objects; i++)
1145                 check_object(sorted_by_offset[i]);
1146
1147         free(sorted_by_offset);
1148 }
1149
1150 /*
1151  * We search for deltas in a list sorted by type, by filename hash, and then
1152  * by size, so that we see progressively smaller and smaller files.
1153  * That's because we prefer deltas to be from the bigger file
1154  * to the smaller -- deletes are potentially cheaper, but perhaps
1155  * more importantly, the bigger file is likely the more recent
1156  * one.  The deepest deltas are therefore the oldest objects which are
1157  * less susceptible to be accessed often.
1158  */
1159 static int type_size_sort(const void *_a, const void *_b)
1160 {
1161         const struct object_entry *a = *(struct object_entry **)_a;
1162         const struct object_entry *b = *(struct object_entry **)_b;
1163
1164         if (a->type > b->type)
1165                 return -1;
1166         if (a->type < b->type)
1167                 return 1;
1168         if (a->hash > b->hash)
1169                 return -1;
1170         if (a->hash < b->hash)
1171                 return 1;
1172         if (a->preferred_base > b->preferred_base)
1173                 return -1;
1174         if (a->preferred_base < b->preferred_base)
1175                 return 1;
1176         if (a->size > b->size)
1177                 return -1;
1178         if (a->size < b->size)
1179                 return 1;
1180         return a < b ? -1 : (a > b);  /* newest first */
1181 }
1182
1183 struct unpacked {
1184         struct object_entry *entry;
1185         void *data;
1186         struct delta_index *index;
1187         unsigned depth;
1188 };
1189
1190 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1191                            unsigned long delta_size)
1192 {
1193         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1194                 return 0;
1195
1196         if (delta_size < cache_max_small_delta_size)
1197                 return 1;
1198
1199         /* cache delta, if objects are large enough compared to delta size */
1200         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1201                 return 1;
1202
1203         return 0;
1204 }
1205
1206 #ifdef THREADED_DELTA_SEARCH
1207
1208 static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1209 #define read_lock()             pthread_mutex_lock(&read_mutex)
1210 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1211
1212 static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1213 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1214 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1215
1216 static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1217 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1218 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1219
1220 #else
1221
1222 #define read_lock()             (void)0
1223 #define read_unlock()           (void)0
1224 #define cache_lock()            (void)0
1225 #define cache_unlock()          (void)0
1226 #define progress_lock()         (void)0
1227 #define progress_unlock()       (void)0
1228
1229 #endif
1230
1231 static int try_delta(struct unpacked *trg, struct unpacked *src,
1232                      unsigned max_depth, unsigned long *mem_usage)
1233 {
1234         struct object_entry *trg_entry = trg->entry;
1235         struct object_entry *src_entry = src->entry;
1236         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1237         unsigned ref_depth;
1238         enum object_type type;
1239         void *delta_buf;
1240
1241         /* Don't bother doing diffs between different types */
1242         if (trg_entry->type != src_entry->type)
1243                 return -1;
1244
1245         /*
1246          * We do not bother to try a delta that we discarded
1247          * on an earlier try, but only when reusing delta data.
1248          */
1249         if (reuse_delta && trg_entry->in_pack &&
1250             trg_entry->in_pack == src_entry->in_pack &&
1251             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1252             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1253                 return 0;
1254
1255         /* Let's not bust the allowed depth. */
1256         if (src->depth >= max_depth)
1257                 return 0;
1258
1259         /* Now some size filtering heuristics. */
1260         trg_size = trg_entry->size;
1261         if (!trg_entry->delta) {
1262                 max_size = trg_size/2 - 20;
1263                 ref_depth = 1;
1264         } else {
1265                 max_size = trg_entry->delta_size;
1266                 ref_depth = trg->depth;
1267         }
1268         max_size = max_size * (max_depth - src->depth) /
1269                                                 (max_depth - ref_depth + 1);
1270         if (max_size == 0)
1271                 return 0;
1272         src_size = src_entry->size;
1273         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1274         if (sizediff >= max_size)
1275                 return 0;
1276         if (trg_size < src_size / 32)
1277                 return 0;
1278
1279         /* Load data if not already done */
1280         if (!trg->data) {
1281                 read_lock();
1282                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1283                 read_unlock();
1284                 if (!trg->data)
1285                         die("object %s cannot be read",
1286                             sha1_to_hex(trg_entry->idx.sha1));
1287                 if (sz != trg_size)
1288                         die("object %s inconsistent object length (%lu vs %lu)",
1289                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1290                 *mem_usage += sz;
1291         }
1292         if (!src->data) {
1293                 read_lock();
1294                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1295                 read_unlock();
1296                 if (!src->data)
1297                         die("object %s cannot be read",
1298                             sha1_to_hex(src_entry->idx.sha1));
1299                 if (sz != src_size)
1300                         die("object %s inconsistent object length (%lu vs %lu)",
1301                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1302                 *mem_usage += sz;
1303         }
1304         if (!src->index) {
1305                 src->index = create_delta_index(src->data, src_size);
1306                 if (!src->index) {
1307                         static int warned = 0;
1308                         if (!warned++)
1309                                 warning("suboptimal pack - out of memory");
1310                         return 0;
1311                 }
1312                 *mem_usage += sizeof_delta_index(src->index);
1313         }
1314
1315         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1316         if (!delta_buf)
1317                 return 0;
1318
1319         if (trg_entry->delta) {
1320                 /* Prefer only shallower same-sized deltas. */
1321                 if (delta_size == trg_entry->delta_size &&
1322                     src->depth + 1 >= trg->depth) {
1323                         free(delta_buf);
1324                         return 0;
1325                 }
1326         }
1327
1328         /*
1329          * Handle memory allocation outside of the cache
1330          * accounting lock.  Compiler will optimize the strangeness
1331          * away when THREADED_DELTA_SEARCH is not defined.
1332          */
1333         free(trg_entry->delta_data);
1334         cache_lock();
1335         if (trg_entry->delta_data) {
1336                 delta_cache_size -= trg_entry->delta_size;
1337                 trg_entry->delta_data = NULL;
1338         }
1339         if (delta_cacheable(src_size, trg_size, delta_size)) {
1340                 delta_cache_size += delta_size;
1341                 cache_unlock();
1342                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1343         } else {
1344                 cache_unlock();
1345                 free(delta_buf);
1346         }
1347
1348         trg_entry->delta = src_entry;
1349         trg_entry->delta_size = delta_size;
1350         trg->depth = src->depth + 1;
1351
1352         return 1;
1353 }
1354
1355 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1356 {
1357         struct object_entry *child = me->delta_child;
1358         unsigned int m = n;
1359         while (child) {
1360                 unsigned int c = check_delta_limit(child, n + 1);
1361                 if (m < c)
1362                         m = c;
1363                 child = child->delta_sibling;
1364         }
1365         return m;
1366 }
1367
1368 static unsigned long free_unpacked(struct unpacked *n)
1369 {
1370         unsigned long freed_mem = sizeof_delta_index(n->index);
1371         free_delta_index(n->index);
1372         n->index = NULL;
1373         if (n->data) {
1374                 freed_mem += n->entry->size;
1375                 free(n->data);
1376                 n->data = NULL;
1377         }
1378         n->entry = NULL;
1379         n->depth = 0;
1380         return freed_mem;
1381 }
1382
1383 static void find_deltas(struct object_entry **list, unsigned *list_size,
1384                         int window, int depth, unsigned *processed)
1385 {
1386         uint32_t i, idx = 0, count = 0;
1387         unsigned int array_size = window * sizeof(struct unpacked);
1388         struct unpacked *array;
1389         unsigned long mem_usage = 0;
1390
1391         array = xmalloc(array_size);
1392         memset(array, 0, array_size);
1393
1394         for (;;) {
1395                 struct object_entry *entry;
1396                 struct unpacked *n = array + idx;
1397                 int j, max_depth, best_base = -1;
1398
1399                 progress_lock();
1400                 if (!*list_size) {
1401                         progress_unlock();
1402                         break;
1403                 }
1404                 entry = *list++;
1405                 (*list_size)--;
1406                 if (!entry->preferred_base) {
1407                         (*processed)++;
1408                         display_progress(progress_state, *processed);
1409                 }
1410                 progress_unlock();
1411
1412                 mem_usage -= free_unpacked(n);
1413                 n->entry = entry;
1414
1415                 while (window_memory_limit &&
1416                        mem_usage > window_memory_limit &&
1417                        count > 1) {
1418                         uint32_t tail = (idx + window - count) % window;
1419                         mem_usage -= free_unpacked(array + tail);
1420                         count--;
1421                 }
1422
1423                 /* We do not compute delta to *create* objects we are not
1424                  * going to pack.
1425                  */
1426                 if (entry->preferred_base)
1427                         goto next;
1428
1429                 /*
1430                  * If the current object is at pack edge, take the depth the
1431                  * objects that depend on the current object into account
1432                  * otherwise they would become too deep.
1433                  */
1434                 max_depth = depth;
1435                 if (entry->delta_child) {
1436                         max_depth -= check_delta_limit(entry, 0);
1437                         if (max_depth <= 0)
1438                                 goto next;
1439                 }
1440
1441                 j = window;
1442                 while (--j > 0) {
1443                         int ret;
1444                         uint32_t other_idx = idx + j;
1445                         struct unpacked *m;
1446                         if (other_idx >= window)
1447                                 other_idx -= window;
1448                         m = array + other_idx;
1449                         if (!m->entry)
1450                                 break;
1451                         ret = try_delta(n, m, max_depth, &mem_usage);
1452                         if (ret < 0)
1453                                 break;
1454                         else if (ret > 0)
1455                                 best_base = other_idx;
1456                 }
1457
1458                 /*
1459                  * If we decided to cache the delta data, then it is best
1460                  * to compress it right away.  First because we have to do
1461                  * it anyway, and doing it here while we're threaded will
1462                  * save a lot of time in the non threaded write phase,
1463                  * as well as allow for caching more deltas within
1464                  * the same cache size limit.
1465                  * ...
1466                  * But only if not writing to stdout, since in that case
1467                  * the network is most likely throttling writes anyway,
1468                  * and therefore it is best to go to the write phase ASAP
1469                  * instead, as we can afford spending more time compressing
1470                  * between writes at that moment.
1471                  */
1472                 if (entry->delta_data && !pack_to_stdout) {
1473                         entry->z_delta_size = do_compress(&entry->delta_data,
1474                                                           entry->delta_size);
1475                         cache_lock();
1476                         delta_cache_size -= entry->delta_size;
1477                         delta_cache_size += entry->z_delta_size;
1478                         cache_unlock();
1479                 }
1480
1481                 /* if we made n a delta, and if n is already at max
1482                  * depth, leaving it in the window is pointless.  we
1483                  * should evict it first.
1484                  */
1485                 if (entry->delta && max_depth <= n->depth)
1486                         continue;
1487
1488                 /*
1489                  * Move the best delta base up in the window, after the
1490                  * currently deltified object, to keep it longer.  It will
1491                  * be the first base object to be attempted next.
1492                  */
1493                 if (entry->delta) {
1494                         struct unpacked swap = array[best_base];
1495                         int dist = (window + idx - best_base) % window;
1496                         int dst = best_base;
1497                         while (dist--) {
1498                                 int src = (dst + 1) % window;
1499                                 array[dst] = array[src];
1500                                 dst = src;
1501                         }
1502                         array[dst] = swap;
1503                 }
1504
1505                 next:
1506                 idx++;
1507                 if (count + 1 < window)
1508                         count++;
1509                 if (idx >= window)
1510                         idx = 0;
1511         }
1512
1513         for (i = 0; i < window; ++i) {
1514                 free_delta_index(array[i].index);
1515                 free(array[i].data);
1516         }
1517         free(array);
1518 }
1519
1520 #ifdef THREADED_DELTA_SEARCH
1521
1522 /*
1523  * The main thread waits on the condition that (at least) one of the workers
1524  * has stopped working (which is indicated in the .working member of
1525  * struct thread_params).
1526  * When a work thread has completed its work, it sets .working to 0 and
1527  * signals the main thread and waits on the condition that .data_ready
1528  * becomes 1.
1529  */
1530
1531 struct thread_params {
1532         pthread_t thread;
1533         struct object_entry **list;
1534         unsigned list_size;
1535         unsigned remaining;
1536         int window;
1537         int depth;
1538         int working;
1539         int data_ready;
1540         pthread_mutex_t mutex;
1541         pthread_cond_t cond;
1542         unsigned *processed;
1543 };
1544
1545 static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
1546
1547 static void *threaded_find_deltas(void *arg)
1548 {
1549         struct thread_params *me = arg;
1550
1551         while (me->remaining) {
1552                 find_deltas(me->list, &me->remaining,
1553                             me->window, me->depth, me->processed);
1554
1555                 progress_lock();
1556                 me->working = 0;
1557                 pthread_cond_signal(&progress_cond);
1558                 progress_unlock();
1559
1560                 /*
1561                  * We must not set ->data_ready before we wait on the
1562                  * condition because the main thread may have set it to 1
1563                  * before we get here. In order to be sure that new
1564                  * work is available if we see 1 in ->data_ready, it
1565                  * was initialized to 0 before this thread was spawned
1566                  * and we reset it to 0 right away.
1567                  */
1568                 pthread_mutex_lock(&me->mutex);
1569                 while (!me->data_ready)
1570                         pthread_cond_wait(&me->cond, &me->mutex);
1571                 me->data_ready = 0;
1572                 pthread_mutex_unlock(&me->mutex);
1573         }
1574         /* leave ->working 1 so that this doesn't get more work assigned */
1575         return NULL;
1576 }
1577
1578 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1579                            int window, int depth, unsigned *processed)
1580 {
1581         struct thread_params p[delta_search_threads];
1582         int i, ret, active_threads = 0;
1583
1584         if (delta_search_threads <= 1) {
1585                 find_deltas(list, &list_size, window, depth, processed);
1586                 return;
1587         }
1588
1589         /* Partition the work amongst work threads. */
1590         for (i = 0; i < delta_search_threads; i++) {
1591                 unsigned sub_size = list_size / (delta_search_threads - i);
1592
1593                 p[i].window = window;
1594                 p[i].depth = depth;
1595                 p[i].processed = processed;
1596                 p[i].working = 1;
1597                 p[i].data_ready = 0;
1598
1599                 /* try to split chunks on "path" boundaries */
1600                 while (sub_size && sub_size < list_size &&
1601                        list[sub_size]->hash &&
1602                        list[sub_size]->hash == list[sub_size-1]->hash)
1603                         sub_size++;
1604
1605                 p[i].list = list;
1606                 p[i].list_size = sub_size;
1607                 p[i].remaining = sub_size;
1608
1609                 list += sub_size;
1610                 list_size -= sub_size;
1611         }
1612
1613         /* Start work threads. */
1614         for (i = 0; i < delta_search_threads; i++) {
1615                 if (!p[i].list_size)
1616                         continue;
1617                 pthread_mutex_init(&p[i].mutex, NULL);
1618                 pthread_cond_init(&p[i].cond, NULL);
1619                 ret = pthread_create(&p[i].thread, NULL,
1620                                      threaded_find_deltas, &p[i]);
1621                 if (ret)
1622                         die("unable to create thread: %s", strerror(ret));
1623                 active_threads++;
1624         }
1625
1626         /*
1627          * Now let's wait for work completion.  Each time a thread is done
1628          * with its work, we steal half of the remaining work from the
1629          * thread with the largest number of unprocessed objects and give
1630          * it to that newly idle thread.  This ensure good load balancing
1631          * until the remaining object list segments are simply too short
1632          * to be worth splitting anymore.
1633          */
1634         while (active_threads) {
1635                 struct thread_params *target = NULL;
1636                 struct thread_params *victim = NULL;
1637                 unsigned sub_size = 0;
1638
1639                 progress_lock();
1640                 for (;;) {
1641                         for (i = 0; !target && i < delta_search_threads; i++)
1642                                 if (!p[i].working)
1643                                         target = &p[i];
1644                         if (target)
1645                                 break;
1646                         pthread_cond_wait(&progress_cond, &progress_mutex);
1647                 }
1648
1649                 for (i = 0; i < delta_search_threads; i++)
1650                         if (p[i].remaining > 2*window &&
1651                             (!victim || victim->remaining < p[i].remaining))
1652                                 victim = &p[i];
1653                 if (victim) {
1654                         sub_size = victim->remaining / 2;
1655                         list = victim->list + victim->list_size - sub_size;
1656                         while (sub_size && list[0]->hash &&
1657                                list[0]->hash == list[-1]->hash) {
1658                                 list++;
1659                                 sub_size--;
1660                         }
1661                         if (!sub_size) {
1662                                 /*
1663                                  * It is possible for some "paths" to have
1664                                  * so many objects that no hash boundary
1665                                  * might be found.  Let's just steal the
1666                                  * exact half in that case.
1667                                  */
1668                                 sub_size = victim->remaining / 2;
1669                                 list -= sub_size;
1670                         }
1671                         target->list = list;
1672                         victim->list_size -= sub_size;
1673                         victim->remaining -= sub_size;
1674                 }
1675                 target->list_size = sub_size;
1676                 target->remaining = sub_size;
1677                 target->working = 1;
1678                 progress_unlock();
1679
1680                 pthread_mutex_lock(&target->mutex);
1681                 target->data_ready = 1;
1682                 pthread_cond_signal(&target->cond);
1683                 pthread_mutex_unlock(&target->mutex);
1684
1685                 if (!sub_size) {
1686                         pthread_join(target->thread, NULL);
1687                         pthread_cond_destroy(&target->cond);
1688                         pthread_mutex_destroy(&target->mutex);
1689                         active_threads--;
1690                 }
1691         }
1692 }
1693
1694 #else
1695 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1696 #endif
1697
1698 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1699 {
1700         unsigned char peeled[20];
1701
1702         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1703             !peel_ref(path, peeled)        && /* peelable? */
1704             !is_null_sha1(peeled)          && /* annotated tag? */
1705             locate_object_entry(peeled))      /* object packed? */
1706                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1707         return 0;
1708 }
1709
1710 static void prepare_pack(int window, int depth)
1711 {
1712         struct object_entry **delta_list;
1713         uint32_t i, nr_deltas;
1714         unsigned n;
1715
1716         get_object_details();
1717
1718         if (!nr_objects || !window || !depth)
1719                 return;
1720
1721         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1722         nr_deltas = n = 0;
1723
1724         for (i = 0; i < nr_objects; i++) {
1725                 struct object_entry *entry = objects + i;
1726
1727                 if (entry->delta)
1728                         /* This happens if we decided to reuse existing
1729                          * delta from a pack.  "reuse_delta &&" is implied.
1730                          */
1731                         continue;
1732
1733                 if (entry->size < 50)
1734                         continue;
1735
1736                 if (entry->no_try_delta)
1737                         continue;
1738
1739                 if (!entry->preferred_base) {
1740                         nr_deltas++;
1741                         if (entry->type < 0)
1742                                 die("unable to get type of object %s",
1743                                     sha1_to_hex(entry->idx.sha1));
1744                 }
1745
1746                 delta_list[n++] = entry;
1747         }
1748
1749         if (nr_deltas && n > 1) {
1750                 unsigned nr_done = 0;
1751                 if (progress)
1752                         progress_state = start_progress("Compressing objects",
1753                                                         nr_deltas);
1754                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1755                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1756                 stop_progress(&progress_state);
1757                 if (nr_done != nr_deltas)
1758                         die("inconsistency with delta count");
1759         }
1760         free(delta_list);
1761 }
1762
1763 static int git_pack_config(const char *k, const char *v, void *cb)
1764 {
1765         if(!strcmp(k, "pack.window")) {
1766                 window = git_config_int(k, v);
1767                 return 0;
1768         }
1769         if (!strcmp(k, "pack.windowmemory")) {
1770                 window_memory_limit = git_config_ulong(k, v);
1771                 return 0;
1772         }
1773         if (!strcmp(k, "pack.depth")) {
1774                 depth = git_config_int(k, v);
1775                 return 0;
1776         }
1777         if (!strcmp(k, "pack.compression")) {
1778                 int level = git_config_int(k, v);
1779                 if (level == -1)
1780                         level = Z_DEFAULT_COMPRESSION;
1781                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1782                         die("bad pack compression level %d", level);
1783                 pack_compression_level = level;
1784                 pack_compression_seen = 1;
1785                 return 0;
1786         }
1787         if (!strcmp(k, "pack.deltacachesize")) {
1788                 max_delta_cache_size = git_config_int(k, v);
1789                 return 0;
1790         }
1791         if (!strcmp(k, "pack.deltacachelimit")) {
1792                 cache_max_small_delta_size = git_config_int(k, v);
1793                 return 0;
1794         }
1795         if (!strcmp(k, "pack.threads")) {
1796                 delta_search_threads = git_config_int(k, v);
1797                 if (delta_search_threads < 0)
1798                         die("invalid number of threads specified (%d)",
1799                             delta_search_threads);
1800 #ifndef THREADED_DELTA_SEARCH
1801                 if (delta_search_threads != 1)
1802                         warning("no threads support, ignoring %s", k);
1803 #endif
1804                 return 0;
1805         }
1806         if (!strcmp(k, "pack.indexversion")) {
1807                 pack_idx_default_version = git_config_int(k, v);
1808                 if (pack_idx_default_version > 2)
1809                         die("bad pack.indexversion=%"PRIu32,
1810                                 pack_idx_default_version);
1811                 return 0;
1812         }
1813         if (!strcmp(k, "pack.packsizelimit")) {
1814                 pack_size_limit_cfg = git_config_ulong(k, v);
1815                 return 0;
1816         }
1817         return git_default_config(k, v, cb);
1818 }
1819
1820 static void read_object_list_from_stdin(void)
1821 {
1822         char line[40 + 1 + PATH_MAX + 2];
1823         unsigned char sha1[20];
1824
1825         for (;;) {
1826                 if (!fgets(line, sizeof(line), stdin)) {
1827                         if (feof(stdin))
1828                                 break;
1829                         if (!ferror(stdin))
1830                                 die("fgets returned NULL, not EOF, not error!");
1831                         if (errno != EINTR)
1832                                 die("fgets: %s", strerror(errno));
1833                         clearerr(stdin);
1834                         continue;
1835                 }
1836                 if (line[0] == '-') {
1837                         if (get_sha1_hex(line+1, sha1))
1838                                 die("expected edge sha1, got garbage:\n %s",
1839                                     line);
1840                         add_preferred_base(sha1);
1841                         continue;
1842                 }
1843                 if (get_sha1_hex(line, sha1))
1844                         die("expected sha1, got garbage:\n %s", line);
1845
1846                 add_preferred_base_object(line+41);
1847                 add_object_entry(sha1, 0, line+41, 0);
1848         }
1849 }
1850
1851 #define OBJECT_ADDED (1u<<20)
1852
1853 static void show_commit(struct commit *commit)
1854 {
1855         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1856         commit->object.flags |= OBJECT_ADDED;
1857 }
1858
1859 static void show_object(struct object_array_entry *p)
1860 {
1861         add_preferred_base_object(p->name);
1862         add_object_entry(p->item->sha1, p->item->type, p->name, 0);
1863         p->item->flags |= OBJECT_ADDED;
1864 }
1865
1866 static void show_edge(struct commit *commit)
1867 {
1868         add_preferred_base(commit->object.sha1);
1869 }
1870
1871 struct in_pack_object {
1872         off_t offset;
1873         struct object *object;
1874 };
1875
1876 struct in_pack {
1877         int alloc;
1878         int nr;
1879         struct in_pack_object *array;
1880 };
1881
1882 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1883 {
1884         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1885         in_pack->array[in_pack->nr].object = object;
1886         in_pack->nr++;
1887 }
1888
1889 /*
1890  * Compare the objects in the offset order, in order to emulate the
1891  * "git rev-list --objects" output that produced the pack originally.
1892  */
1893 static int ofscmp(const void *a_, const void *b_)
1894 {
1895         struct in_pack_object *a = (struct in_pack_object *)a_;
1896         struct in_pack_object *b = (struct in_pack_object *)b_;
1897
1898         if (a->offset < b->offset)
1899                 return -1;
1900         else if (a->offset > b->offset)
1901                 return 1;
1902         else
1903                 return hashcmp(a->object->sha1, b->object->sha1);
1904 }
1905
1906 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1907 {
1908         struct packed_git *p;
1909         struct in_pack in_pack;
1910         uint32_t i;
1911
1912         memset(&in_pack, 0, sizeof(in_pack));
1913
1914         for (p = packed_git; p; p = p->next) {
1915                 const unsigned char *sha1;
1916                 struct object *o;
1917
1918                 for (i = 0; i < revs->num_ignore_packed; i++) {
1919                         if (matches_pack_name(p, revs->ignore_packed[i]))
1920                                 break;
1921                 }
1922                 if (revs->num_ignore_packed <= i)
1923                         continue;
1924                 if (open_pack_index(p))
1925                         die("cannot open pack index");
1926
1927                 ALLOC_GROW(in_pack.array,
1928                            in_pack.nr + p->num_objects,
1929                            in_pack.alloc);
1930
1931                 for (i = 0; i < p->num_objects; i++) {
1932                         sha1 = nth_packed_object_sha1(p, i);
1933                         o = lookup_unknown_object(sha1);
1934                         if (!(o->flags & OBJECT_ADDED))
1935                                 mark_in_pack_object(o, p, &in_pack);
1936                         o->flags |= OBJECT_ADDED;
1937                 }
1938         }
1939
1940         if (in_pack.nr) {
1941                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
1942                       ofscmp);
1943                 for (i = 0; i < in_pack.nr; i++) {
1944                         struct object *o = in_pack.array[i].object;
1945                         add_object_entry(o->sha1, o->type, "", 0);
1946                 }
1947         }
1948         free(in_pack.array);
1949 }
1950
1951 static void loosen_unused_packed_objects(struct rev_info *revs)
1952 {
1953         struct packed_git *p;
1954         uint32_t i;
1955         const unsigned char *sha1;
1956
1957         for (p = packed_git; p; p = p->next) {
1958                 for (i = 0; i < revs->num_ignore_packed; i++) {
1959                         if (matches_pack_name(p, revs->ignore_packed[i]))
1960                                 break;
1961                 }
1962                 if (revs->num_ignore_packed <= i)
1963                         continue;
1964
1965                 if (open_pack_index(p))
1966                         die("cannot open pack index");
1967
1968                 for (i = 0; i < p->num_objects; i++) {
1969                         sha1 = nth_packed_object_sha1(p, i);
1970                         if (!locate_object_entry(sha1))
1971                                 if (force_object_loose(sha1, p->mtime))
1972                                         die("unable to force loose object");
1973                 }
1974         }
1975 }
1976
1977 static void get_object_list(int ac, const char **av)
1978 {
1979         struct rev_info revs;
1980         char line[1000];
1981         int flags = 0;
1982
1983         init_revisions(&revs, NULL);
1984         save_commit_buffer = 0;
1985         setup_revisions(ac, av, &revs, NULL);
1986
1987         while (fgets(line, sizeof(line), stdin) != NULL) {
1988                 int len = strlen(line);
1989                 if (len && line[len - 1] == '\n')
1990                         line[--len] = 0;
1991                 if (!len)
1992                         break;
1993                 if (*line == '-') {
1994                         if (!strcmp(line, "--not")) {
1995                                 flags ^= UNINTERESTING;
1996                                 continue;
1997                         }
1998                         die("not a rev '%s'", line);
1999                 }
2000                 if (handle_revision_arg(line, &revs, flags, 1))
2001                         die("bad revision '%s'", line);
2002         }
2003
2004         if (prepare_revision_walk(&revs))
2005                 die("revision walk setup failed");
2006         mark_edges_uninteresting(revs.commits, &revs, show_edge);
2007         traverse_commit_list(&revs, show_commit, show_object);
2008
2009         if (keep_unreachable)
2010                 add_objects_in_unpacked_packs(&revs);
2011         if (unpack_unreachable)
2012                 loosen_unused_packed_objects(&revs);
2013 }
2014
2015 static int adjust_perm(const char *path, mode_t mode)
2016 {
2017         if (chmod(path, mode))
2018                 return -1;
2019         return adjust_shared_perm(path);
2020 }
2021
2022 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2023 {
2024         int use_internal_rev_list = 0;
2025         int thin = 0;
2026         uint32_t i;
2027         const char **rp_av;
2028         int rp_ac_alloc = 64;
2029         int rp_ac;
2030
2031         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2032
2033         rp_av[0] = "pack-objects";
2034         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2035         rp_ac = 2;
2036
2037         git_config(git_pack_config, NULL);
2038         if (!pack_compression_seen && core_compression_seen)
2039                 pack_compression_level = core_compression_level;
2040
2041         progress = isatty(2);
2042         for (i = 1; i < argc; i++) {
2043                 const char *arg = argv[i];
2044
2045                 if (*arg != '-')
2046                         break;
2047
2048                 if (!strcmp("--non-empty", arg)) {
2049                         non_empty = 1;
2050                         continue;
2051                 }
2052                 if (!strcmp("--local", arg)) {
2053                         local = 1;
2054                         continue;
2055                 }
2056                 if (!strcmp("--incremental", arg)) {
2057                         incremental = 1;
2058                         continue;
2059                 }
2060                 if (!strcmp("--honor-pack-keep", arg)) {
2061                         ignore_packed_keep = 1;
2062                         continue;
2063                 }
2064                 if (!prefixcmp(arg, "--compression=")) {
2065                         char *end;
2066                         int level = strtoul(arg+14, &end, 0);
2067                         if (!arg[14] || *end)
2068                                 usage(pack_usage);
2069                         if (level == -1)
2070                                 level = Z_DEFAULT_COMPRESSION;
2071                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2072                                 die("bad pack compression level %d", level);
2073                         pack_compression_level = level;
2074                         continue;
2075                 }
2076                 if (!prefixcmp(arg, "--max-pack-size=")) {
2077                         char *end;
2078                         pack_size_limit_cfg = 0;
2079                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2080                         if (!arg[16] || *end)
2081                                 usage(pack_usage);
2082                         continue;
2083                 }
2084                 if (!prefixcmp(arg, "--window=")) {
2085                         char *end;
2086                         window = strtoul(arg+9, &end, 0);
2087                         if (!arg[9] || *end)
2088                                 usage(pack_usage);
2089                         continue;
2090                 }
2091                 if (!prefixcmp(arg, "--window-memory=")) {
2092                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2093                                 usage(pack_usage);
2094                         continue;
2095                 }
2096                 if (!prefixcmp(arg, "--threads=")) {
2097                         char *end;
2098                         delta_search_threads = strtoul(arg+10, &end, 0);
2099                         if (!arg[10] || *end || delta_search_threads < 0)
2100                                 usage(pack_usage);
2101 #ifndef THREADED_DELTA_SEARCH
2102                         if (delta_search_threads != 1)
2103                                 warning("no threads support, "
2104                                         "ignoring %s", arg);
2105 #endif
2106                         continue;
2107                 }
2108                 if (!prefixcmp(arg, "--depth=")) {
2109                         char *end;
2110                         depth = strtoul(arg+8, &end, 0);
2111                         if (!arg[8] || *end)
2112                                 usage(pack_usage);
2113                         continue;
2114                 }
2115                 if (!strcmp("--progress", arg)) {
2116                         progress = 1;
2117                         continue;
2118                 }
2119                 if (!strcmp("--all-progress", arg)) {
2120                         progress = 2;
2121                         continue;
2122                 }
2123                 if (!strcmp("-q", arg)) {
2124                         progress = 0;
2125                         continue;
2126                 }
2127                 if (!strcmp("--no-reuse-delta", arg)) {
2128                         reuse_delta = 0;
2129                         continue;
2130                 }
2131                 if (!strcmp("--no-reuse-object", arg)) {
2132                         reuse_object = reuse_delta = 0;
2133                         continue;
2134                 }
2135                 if (!strcmp("--delta-base-offset", arg)) {
2136                         allow_ofs_delta = 1;
2137                         continue;
2138                 }
2139                 if (!strcmp("--stdout", arg)) {
2140                         pack_to_stdout = 1;
2141                         continue;
2142                 }
2143                 if (!strcmp("--revs", arg)) {
2144                         use_internal_rev_list = 1;
2145                         continue;
2146                 }
2147                 if (!strcmp("--keep-unreachable", arg)) {
2148                         keep_unreachable = 1;
2149                         continue;
2150                 }
2151                 if (!strcmp("--unpack-unreachable", arg)) {
2152                         unpack_unreachable = 1;
2153                         continue;
2154                 }
2155                 if (!strcmp("--include-tag", arg)) {
2156                         include_tag = 1;
2157                         continue;
2158                 }
2159                 if (!strcmp("--unpacked", arg) ||
2160                     !prefixcmp(arg, "--unpacked=") ||
2161                     !strcmp("--reflog", arg) ||
2162                     !strcmp("--all", arg)) {
2163                         use_internal_rev_list = 1;
2164                         if (rp_ac >= rp_ac_alloc - 1) {
2165                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2166                                 rp_av = xrealloc(rp_av,
2167                                                  rp_ac_alloc * sizeof(*rp_av));
2168                         }
2169                         rp_av[rp_ac++] = arg;
2170                         continue;
2171                 }
2172                 if (!strcmp("--thin", arg)) {
2173                         use_internal_rev_list = 1;
2174                         thin = 1;
2175                         rp_av[1] = "--objects-edge";
2176                         continue;
2177                 }
2178                 if (!prefixcmp(arg, "--index-version=")) {
2179                         char *c;
2180                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2181                         if (pack_idx_default_version > 2)
2182                                 die("bad %s", arg);
2183                         if (*c == ',')
2184                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2185                         if (*c || pack_idx_off32_limit & 0x80000000)
2186                                 die("bad %s", arg);
2187                         continue;
2188                 }
2189                 usage(pack_usage);
2190         }
2191
2192         /* Traditionally "pack-objects [options] base extra" failed;
2193          * we would however want to take refs parameter that would
2194          * have been given to upstream rev-list ourselves, which means
2195          * we somehow want to say what the base name is.  So the
2196          * syntax would be:
2197          *
2198          * pack-objects [options] base <refs...>
2199          *
2200          * in other words, we would treat the first non-option as the
2201          * base_name and send everything else to the internal revision
2202          * walker.
2203          */
2204
2205         if (!pack_to_stdout)
2206                 base_name = argv[i++];
2207
2208         if (pack_to_stdout != !base_name)
2209                 usage(pack_usage);
2210
2211         if (!pack_to_stdout && !pack_size_limit)
2212                 pack_size_limit = pack_size_limit_cfg;
2213
2214         if (pack_to_stdout && pack_size_limit)
2215                 die("--max-pack-size cannot be used to build a pack for transfer.");
2216
2217         if (!pack_to_stdout && thin)
2218                 die("--thin cannot be used to build an indexable pack.");
2219
2220         if (keep_unreachable && unpack_unreachable)
2221                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2222
2223 #ifdef THREADED_DELTA_SEARCH
2224         if (!delta_search_threads)      /* --threads=0 means autodetect */
2225                 delta_search_threads = online_cpus();
2226 #endif
2227
2228         prepare_packed_git();
2229
2230         if (progress)
2231                 progress_state = start_progress("Counting objects", 0);
2232         if (!use_internal_rev_list)
2233                 read_object_list_from_stdin();
2234         else {
2235                 rp_av[rp_ac] = NULL;
2236                 get_object_list(rp_ac, rp_av);
2237         }
2238         if (include_tag && nr_result)
2239                 for_each_ref(add_ref_tag, NULL);
2240         stop_progress(&progress_state);
2241
2242         if (non_empty && !nr_result)
2243                 return 0;
2244         if (nr_result)
2245                 prepare_pack(window, depth);
2246         write_pack_file();
2247         if (progress)
2248                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2249                         " reused %"PRIu32" (delta %"PRIu32")\n",
2250                         written, written_delta, reused, reused_delta);
2251         return 0;
2252 }