builtin-pack-objects.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "attr.h"
   4 #include "object.h"
   5 #include "blob.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "tree.h"
   9 #include "delta.h"
  10 #include "pack.h"
  11 #include "pack-revindex.h"
  12 #include "csum-file.h"
  13 #include "tree-walk.h"
  14 #include "diff.h"
  15 #include "revision.h"
  16 #include "list-objects.h"
  17 #include "progress.h"
  18 #include "refs.h"
  19
  20 #ifdef THREADED_DELTA_SEARCH
  21 #include "thread-utils.h"
  22 #include <pthread.h>
  23 #endif
  24
  25 static const char pack_usage[] = "\
  26 git-pack-objects [{ -q | --progress | --all-progress }] \n\
  27         [--max-pack-size=N] [--local] [--incremental] \n\
  28         [--window=N] [--window-memory=N] [--depth=N] \n\
  29         [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
  30         [--threads=N] [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
  31         [--stdout | base-name] [--include-tag] \n\
  32         [--keep-unreachable | --unpack-unreachable] \n\
  33         [<ref-list | <object-list]";
  34
  35 struct object_entry {
  36         struct pack_idx_entry idx;
  37         unsigned long size;     /* uncompressed size */
  38         struct packed_git *in_pack;     /* already in pack */
  39         off_t in_pack_offset;
  40         struct object_entry *delta;     /* delta base object */
  41         struct object_entry *delta_child; /* deltified objects who bases me */
  42         struct object_entry *delta_sibling; /* other deltified objects who
  43                                              * uses the same base as me
  44                                              */
  45         void *delta_data;       /* cached delta (uncompressed) */
  46         unsigned long delta_size;       /* delta data size (uncompressed) */
  47         unsigned long z_delta_size;     /* delta data size (compressed) */
  48         unsigned int hash;      /* name hint hash */
  49         enum object_type type;
  50         enum object_type in_pack_type;  /* could be delta */
  51         unsigned char in_pack_header_size;
  52         unsigned char preferred_base; /* we do not pack this, but is available
  53                                        * to be used as the base object to delta
  54                                        * objects against.
  55                                        */
  56         unsigned char no_try_delta;
  57 };
  58
  59 /*
  60  * Objects we are going to pack are collected in objects array (dynamically
  61  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  62  * in the order we see -- typically rev-list --objects order that gives us
  63  * nice "minimum seek" order.
  64  */
  65 static struct object_entry *objects;
  66 static struct pack_idx_entry **written_list;
  67 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
  68
  69 static int non_empty;
  70 static int reuse_delta = 1, reuse_object = 1;
  71 static int keep_unreachable, unpack_unreachable, include_tag;
  72 static int local;
  73 static int incremental;
  74 static int allow_ofs_delta;
  75 static const char *base_name;
  76 static int progress = 1;
  77 static int window = 10;
  78 static uint32_t pack_size_limit, pack_size_limit_cfg;
  79 static int depth = 50;
  80 static int delta_search_threads = 1;
  81 static int pack_to_stdout;
  82 static int num_preferred_base;
  83 static struct progress *progress_state;
  84 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  85 static int pack_compression_seen;
  86
  87 static unsigned long delta_cache_size = 0;
  88 static unsigned long max_delta_cache_size = 0;
  89 static unsigned long cache_max_small_delta_size = 1000;
  90
  91 static unsigned long window_memory_limit = 0;
  92
  93 /*
  94  * The object names in objects array are hashed with this hashtable,
  95  * to help looking up the entry by object name.
  96  * This hashtable is built after all the objects are seen.
  97  */
  98 static int *object_ix;
  99 static int object_ix_hashsz;
 100
 101 /*
 102  * stats
 103  */
 104 static uint32_t written, written_delta;
 105 static uint32_t reused, reused_delta;
 106
 107
 108 static void *get_delta(struct object_entry *entry)
 109 {
 110         unsigned long size, base_size, delta_size;
 111         void *buf, *base_buf, *delta_buf;
 112         enum object_type type;
 113
 114         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 115         if (!buf)
 116                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 117         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
 118         if (!base_buf)
 119                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 120         delta_buf = diff_delta(base_buf, base_size,
 121                                buf, size, &delta_size, 0);
 122         if (!delta_buf || delta_size != entry->delta_size)
 123                 die("delta size changed");
 124         free(buf);
 125         free(base_buf);
 126         return delta_buf;
 127 }
 128
 129 static unsigned long do_compress(void **pptr, unsigned long size)
 130 {
 131         z_stream stream;
 132         void *in, *out;
 133         unsigned long maxsize;
 134
 135         memset(&stream, 0, sizeof(stream));
 136         deflateInit(&stream, pack_compression_level);
 137         maxsize = deflateBound(&stream, size);
 138
 139         in = *pptr;
 140         out = xmalloc(maxsize);
 141         *pptr = out;
 142
 143         stream.next_in = in;
 144         stream.avail_in = size;
 145         stream.next_out = out;
 146         stream.avail_out = maxsize;
 147         while (deflate(&stream, Z_FINISH) == Z_OK)
 148                 ; /* nothing */
 149         deflateEnd(&stream);
 150
 151         free(in);
 152         return stream.total_out;
 153 }
 154
 155 /*
 156  * The per-object header is a pretty dense thing, which is
 157  *  - first byte: low four bits are "size", then three bits of "type",
 158  *    and the high bit is "size continues".
 159  *  - each byte afterwards: low seven bits are size continuation,
 160  *    with the high bit being "size continues"
 161  */
 162 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 163 {
 164         int n = 1;
 165         unsigned char c;
 166
 167         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 168                 die("bad type %d", type);
 169
 170         c = (type << 4) | (size & 15);
 171         size >>= 4;
 172         while (size) {
 173                 *hdr++ = c | 0x80;
 174                 c = size & 0x7f;
 175                 size >>= 7;
 176                 n++;
 177         }
 178         *hdr = c;
 179         return n;
 180 }
 181
 182 /*
 183  * we are going to reuse the existing object data as is.  make
 184  * sure it is not corrupt.
 185  */
 186 static int check_pack_inflate(struct packed_git *p,
 187                 struct pack_window **w_curs,
 188                 off_t offset,
 189                 off_t len,
 190                 unsigned long expect)
 191 {
 192         z_stream stream;
 193         unsigned char fakebuf[4096], *in;
 194         int st;
 195
 196         memset(&stream, 0, sizeof(stream));
 197         inflateInit(&stream);
 198         do {
 199                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 200                 stream.next_in = in;
 201                 stream.next_out = fakebuf;
 202                 stream.avail_out = sizeof(fakebuf);
 203                 st = inflate(&stream, Z_FINISH);
 204                 offset += stream.next_in - in;
 205         } while (st == Z_OK || st == Z_BUF_ERROR);
 206         inflateEnd(&stream);
 207         return (st == Z_STREAM_END &&
 208                 stream.total_out == expect &&
 209                 stream.total_in == len) ? 0 : -1;
 210 }
 211
 212 static void copy_pack_data(struct sha1file *f,
 213                 struct packed_git *p,
 214                 struct pack_window **w_curs,
 215                 off_t offset,
 216                 off_t len)
 217 {
 218         unsigned char *in;
 219         unsigned int avail;
 220
 221         while (len) {
 222                 in = use_pack(p, w_curs, offset, &avail);
 223                 if (avail > len)
 224                         avail = (unsigned int)len;
 225                 sha1write(f, in, avail);
 226                 offset += avail;
 227                 len -= avail;
 228         }
 229 }
 230
 231 static unsigned long write_object(struct sha1file *f,
 232                                   struct object_entry *entry,
 233                                   off_t write_offset)
 234 {
 235         unsigned long size, limit, datalen;
 236         void *buf;
 237         unsigned char header[10], dheader[10];
 238         unsigned hdrlen;
 239         enum object_type type;
 240         int usable_delta, to_reuse;
 241
 242         if (!pack_to_stdout)
 243                 crc32_begin(f);
 244
 245         type = entry->type;
 246
 247         /* write limit if limited packsize and not first object */
 248         limit = pack_size_limit && nr_written ?
 249                         pack_size_limit - write_offset : 0;
 250
 251         if (!entry->delta)
 252                 usable_delta = 0;       /* no delta */
 253         else if (!pack_size_limit)
 254                usable_delta = 1;        /* unlimited packfile */
 255         else if (entry->delta->idx.offset == (off_t)-1)
 256                 usable_delta = 0;       /* base was written to another pack */
 257         else if (entry->delta->idx.offset)
 258                 usable_delta = 1;       /* base already exists in this pack */
 259         else
 260                 usable_delta = 0;       /* base could end up in another pack */
 261
 262         if (!reuse_object)
 263                 to_reuse = 0;   /* explicit */
 264         else if (!entry->in_pack)
 265                 to_reuse = 0;   /* can't reuse what we don't have */
 266         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
 267                                 /* check_object() decided it for us ... */
 268                 to_reuse = usable_delta;
 269                                 /* ... but pack split may override that */
 270         else if (type != entry->in_pack_type)
 271                 to_reuse = 0;   /* pack has delta which is unusable */
 272         else if (entry->delta)
 273                 to_reuse = 0;   /* we want to pack afresh */
 274         else
 275                 to_reuse = 1;   /* we have it in-pack undeltified,
 276                                  * and we do not need to deltify it.
 277                                  */
 278
 279         if (!to_reuse) {
 280                 if (!usable_delta) {
 281                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 282                         if (!buf)
 283                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 284                         /*
 285                          * make sure no cached delta data remains from a
 286                          * previous attempt before a pack split occured.
 287                          */
 288                         free(entry->delta_data);
 289                         entry->delta_data = NULL;
 290                         entry->z_delta_size = 0;
 291                 } else if (entry->delta_data) {
 292                         size = entry->delta_size;
 293                         buf = entry->delta_data;
 294                         entry->delta_data = NULL;
 295                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 296                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 297                 } else {
 298                         buf = get_delta(entry);
 299                         size = entry->delta_size;
 300                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 301                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 302                 }
 303
 304                 if (entry->z_delta_size)
 305                         datalen = entry->z_delta_size;
 306                 else
 307                         datalen = do_compress(&buf, size);
 308
 309                 /*
 310                  * The object header is a byte of 'type' followed by zero or
 311                  * more bytes of length.
 312                  */
 313                 hdrlen = encode_header(type, size, header);
 314
 315                 if (type == OBJ_OFS_DELTA) {
 316                         /*
 317                          * Deltas with relative base contain an additional
 318                          * encoding of the relative offset for the delta
 319                          * base from this object's position in the pack.
 320                          */
 321                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 322                         unsigned pos = sizeof(dheader) - 1;
 323                         dheader[pos] = ofs & 127;
 324                         while (ofs >>= 7)
 325                                 dheader[--pos] = 128 | (--ofs & 127);
 326                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 327                                 free(buf);
 328                                 return 0;
 329                         }
 330                         sha1write(f, header, hdrlen);
 331                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 332                         hdrlen += sizeof(dheader) - pos;
 333                 } else if (type == OBJ_REF_DELTA) {
 334                         /*
 335                          * Deltas with a base reference contain
 336                          * an additional 20 bytes for the base sha1.
 337                          */
 338                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 339                                 free(buf);
 340                                 return 0;
 341                         }
 342                         sha1write(f, header, hdrlen);
 343                         sha1write(f, entry->delta->idx.sha1, 20);
 344                         hdrlen += 20;
 345                 } else {
 346                         if (limit && hdrlen + datalen + 20 >= limit) {
 347                                 free(buf);
 348                                 return 0;
 349                         }
 350                         sha1write(f, header, hdrlen);
 351                 }
 352                 sha1write(f, buf, datalen);
 353                 free(buf);
 354         }
 355         else {
 356                 struct packed_git *p = entry->in_pack;
 357                 struct pack_window *w_curs = NULL;
 358                 struct revindex_entry *revidx;
 359                 off_t offset;
 360
 361                 if (entry->delta) {
 362                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 363                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 364                         reused_delta++;
 365                 }
 366                 hdrlen = encode_header(type, entry->size, header);
 367                 offset = entry->in_pack_offset;
 368                 revidx = find_pack_revindex(p, offset);
 369                 datalen = revidx[1].offset - offset;
 370                 if (!pack_to_stdout && p->index_version > 1 &&
 371                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
 372                         die("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 373                 offset += entry->in_pack_header_size;
 374                 datalen -= entry->in_pack_header_size;
 375                 if (type == OBJ_OFS_DELTA) {
 376                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 377                         unsigned pos = sizeof(dheader) - 1;
 378                         dheader[pos] = ofs & 127;
 379                         while (ofs >>= 7)
 380                                 dheader[--pos] = 128 | (--ofs & 127);
 381                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit)
 382                                 return 0;
 383                         sha1write(f, header, hdrlen);
 384                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 385                         hdrlen += sizeof(dheader) - pos;
 386                 } else if (type == OBJ_REF_DELTA) {
 387                         if (limit && hdrlen + 20 + datalen + 20 >= limit)
 388                                 return 0;
 389                         sha1write(f, header, hdrlen);
 390                         sha1write(f, entry->delta->idx.sha1, 20);
 391                         hdrlen += 20;
 392                 } else {
 393                         if (limit && hdrlen + datalen + 20 >= limit)
 394                                 return 0;
 395                         sha1write(f, header, hdrlen);
 396                 }
 397
 398                 if (!pack_to_stdout && p->index_version == 1 &&
 399                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
 400                         die("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 401                 copy_pack_data(f, p, &w_curs, offset, datalen);
 402                 unuse_pack(&w_curs);
 403                 reused++;
 404         }
 405         if (usable_delta)
 406                 written_delta++;
 407         written++;
 408         if (!pack_to_stdout)
 409                 entry->idx.crc32 = crc32_end(f);
 410         return hdrlen + datalen;
 411 }
 412
 413 static int write_one(struct sha1file *f,
 414                                struct object_entry *e,
 415                                off_t *offset)
 416 {
 417         unsigned long size;
 418
 419         /* offset is non zero if object is written already. */
 420         if (e->idx.offset || e->preferred_base)
 421                 return 1;
 422
 423         /* if we are deltified, write out base object first. */
 424         if (e->delta && !write_one(f, e->delta, offset))
 425                 return 0;
 426
 427         e->idx.offset = *offset;
 428         size = write_object(f, e, *offset);
 429         if (!size) {
 430                 e->idx.offset = 0;
 431                 return 0;
 432         }
 433         written_list[nr_written++] = &e->idx;
 434
 435         /* make sure off_t is sufficiently large not to wrap */
 436         if (*offset > *offset + size)
 437                 die("pack too large for current definition of off_t");
 438         *offset += size;
 439         return 1;
 440 }
 441
 442 /* forward declaration for write_pack_file */
 443 static int adjust_perm(const char *path, mode_t mode);
 444
 445 static void write_pack_file(void)
 446 {
 447         uint32_t i = 0, j;
 448         struct sha1file *f;
 449         off_t offset;
 450         struct pack_header hdr;
 451         uint32_t nr_remaining = nr_result;
 452         time_t last_mtime = 0;
 453
 454         if (progress > pack_to_stdout)
 455                 progress_state = start_progress("Writing objects", nr_result);
 456         written_list = xmalloc(nr_objects * sizeof(*written_list));
 457
 458         do {
 459                 unsigned char sha1[20];
 460                 char *pack_tmp_name = NULL;
 461
 462                 if (pack_to_stdout) {
 463                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 464                 } else {
 465                         char tmpname[PATH_MAX];
 466                         int fd;
 467                         snprintf(tmpname, sizeof(tmpname),
 468                                  "%s/tmp_pack_XXXXXX", get_object_directory());
 469                         fd = xmkstemp(tmpname);
 470                         pack_tmp_name = xstrdup(tmpname);
 471                         f = sha1fd(fd, pack_tmp_name);
 472                 }
 473
 474                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
 475                 hdr.hdr_version = htonl(PACK_VERSION);
 476                 hdr.hdr_entries = htonl(nr_remaining);
 477                 sha1write(f, &hdr, sizeof(hdr));
 478                 offset = sizeof(hdr);
 479                 nr_written = 0;
 480                 for (; i < nr_objects; i++) {
 481                         if (!write_one(f, objects + i, &offset))
 482                                 break;
 483                         display_progress(progress_state, written);
 484                 }
 485
 486                 /*
 487                  * Did we write the wrong # entries in the header?
 488                  * If so, rewrite it like in fast-import
 489                  */
 490                 if (pack_to_stdout) {
 491                         sha1close(f, sha1, CSUM_CLOSE);
 492                 } else if (nr_written == nr_remaining) {
 493                         sha1close(f, sha1, CSUM_FSYNC);
 494                 } else {
 495                         int fd = sha1close(f, NULL, 0);
 496                         fixup_pack_header_footer(fd, sha1, pack_tmp_name, nr_written);
 497                         close(fd);
 498                 }
 499
 500                 if (!pack_to_stdout) {
 501                         mode_t mode = umask(0);
 502                         struct stat st;
 503                         char *idx_tmp_name, tmpname[PATH_MAX];
 504
 505                         umask(mode);
 506                         mode = 0444 & ~mode;
 507
 508                         idx_tmp_name = write_idx_file(NULL, written_list,
 509                                                       nr_written, sha1);
 510
 511                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 512                                  base_name, sha1_to_hex(sha1));
 513                         if (adjust_perm(pack_tmp_name, mode))
 514                                 die("unable to make temporary pack file readable: %s",
 515                                     strerror(errno));
 516                         if (rename(pack_tmp_name, tmpname))
 517                                 die("unable to rename temporary pack file: %s",
 518                                     strerror(errno));
 519
 520                         /*
 521                          * Packs are runtime accessed in their mtime
 522                          * order since newer packs are more likely to contain
 523                          * younger objects.  So if we are creating multiple
 524                          * packs then we should modify the mtime of later ones
 525                          * to preserve this property.
 526                          */
 527                         if (stat(tmpname, &st) < 0) {
 528                                 warning("failed to stat %s: %s",
 529                                         tmpname, strerror(errno));
 530                         } else if (!last_mtime) {
 531                                 last_mtime = st.st_mtime;
 532                         } else {
 533                                 struct utimbuf utb;
 534                                 utb.actime = st.st_atime;
 535                                 utb.modtime = --last_mtime;
 536                                 if (utime(tmpname, &utb) < 0)
 537                                         warning("failed utime() on %s: %s",
 538                                                 tmpname, strerror(errno));
 539                         }
 540
 541                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 542                                  base_name, sha1_to_hex(sha1));
 543                         if (adjust_perm(idx_tmp_name, mode))
 544                                 die("unable to make temporary index file readable: %s",
 545                                     strerror(errno));
 546                         if (rename(idx_tmp_name, tmpname))
 547                                 die("unable to rename temporary index file: %s",
 548                                     strerror(errno));
 549
 550                         free(idx_tmp_name);
 551                         free(pack_tmp_name);
 552                         puts(sha1_to_hex(sha1));
 553                 }
 554
 555                 /* mark written objects as written to previous pack */
 556                 for (j = 0; j < nr_written; j++) {
 557                         written_list[j]->offset = (off_t)-1;
 558                 }
 559                 nr_remaining -= nr_written;
 560         } while (nr_remaining && i < nr_objects);
 561
 562         free(written_list);
 563         stop_progress(&progress_state);
 564         if (written != nr_result)
 565                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
 566                         written, nr_result);
 567         /*
 568          * We have scanned through [0 ... i).  Since we have written
 569          * the correct number of objects,  the remaining [i ... nr_objects)
 570          * items must be either already written (due to out-of-order delta base)
 571          * or a preferred base.  Count those which are neither and complain if any.
 572          */
 573         for (j = 0; i < nr_objects; i++) {
 574                 struct object_entry *e = objects + i;
 575                 j += !e->idx.offset && !e->preferred_base;
 576         }
 577         if (j)
 578                 die("wrote %"PRIu32" objects as expected but %"PRIu32
 579                         " unwritten", written, j);
 580 }
 581
 582 static int locate_object_entry_hash(const unsigned char *sha1)
 583 {
 584         int i;
 585         unsigned int ui;
 586         memcpy(&ui, sha1, sizeof(unsigned int));
 587         i = ui % object_ix_hashsz;
 588         while (0 < object_ix[i]) {
 589                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 590                         return i;
 591                 if (++i == object_ix_hashsz)
 592                         i = 0;
 593         }
 594         return -1 - i;
 595 }
 596
 597 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 598 {
 599         int i;
 600
 601         if (!object_ix_hashsz)
 602                 return NULL;
 603
 604         i = locate_object_entry_hash(sha1);
 605         if (0 <= i)
 606                 return &objects[object_ix[i]-1];
 607         return NULL;
 608 }
 609
 610 static void rehash_objects(void)
 611 {
 612         uint32_t i;
 613         struct object_entry *oe;
 614
 615         object_ix_hashsz = nr_objects * 3;
 616         if (object_ix_hashsz < 1024)
 617                 object_ix_hashsz = 1024;
 618         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 619         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 620         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 621                 int ix = locate_object_entry_hash(oe->idx.sha1);
 622                 if (0 <= ix)
 623                         continue;
 624                 ix = -1 - ix;
 625                 object_ix[ix] = i + 1;
 626         }
 627 }
 628
 629 static unsigned name_hash(const char *name)
 630 {
 631         unsigned char c;
 632         unsigned hash = 0;
 633
 634         if (!name)
 635                 return 0;
 636
 637         /*
 638          * This effectively just creates a sortable number from the
 639          * last sixteen non-whitespace characters. Last characters
 640          * count "most", so things that end in ".c" sort together.
 641          */
 642         while ((c = *name++) != 0) {
 643                 if (isspace(c))
 644                         continue;
 645                 hash = (hash >> 2) + (c << 24);
 646         }
 647         return hash;
 648 }
 649
 650 static void setup_delta_attr_check(struct git_attr_check *check)
 651 {
 652         static struct git_attr *attr_delta;
 653
 654         if (!attr_delta)
 655                 attr_delta = git_attr("delta", 5);
 656
 657         check[0].attr = attr_delta;
 658 }
 659
 660 static int no_try_delta(const char *path)
 661 {
 662         struct git_attr_check check[1];
 663
 664         setup_delta_attr_check(check);
 665         if (git_checkattr(path, ARRAY_SIZE(check), check))
 666                 return 0;
 667         if (ATTR_FALSE(check->value))
 668                 return 1;
 669         return 0;
 670 }
 671
 672 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 673                             const char *name, int exclude)
 674 {
 675         struct object_entry *entry;
 676         struct packed_git *p, *found_pack = NULL;
 677         off_t found_offset = 0;
 678         int ix;
 679         unsigned hash = name_hash(name);
 680
 681         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 682         if (ix >= 0) {
 683                 if (exclude) {
 684                         entry = objects + object_ix[ix] - 1;
 685                         if (!entry->preferred_base)
 686                                 nr_result--;
 687                         entry->preferred_base = 1;
 688                 }
 689                 return 0;
 690         }
 691
 692         for (p = packed_git; p; p = p->next) {
 693                 off_t offset = find_pack_entry_one(sha1, p);
 694                 if (offset) {
 695                         if (!found_pack) {
 696                                 found_offset = offset;
 697                                 found_pack = p;
 698                         }
 699                         if (exclude)
 700                                 break;
 701                         if (incremental)
 702                                 return 0;
 703                         if (local && !p->pack_local)
 704                                 return 0;
 705                 }
 706         }
 707
 708         if (nr_objects >= nr_alloc) {
 709                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 710                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 711         }
 712
 713         entry = objects + nr_objects++;
 714         memset(entry, 0, sizeof(*entry));
 715         hashcpy(entry->idx.sha1, sha1);
 716         entry->hash = hash;
 717         if (type)
 718                 entry->type = type;
 719         if (exclude)
 720                 entry->preferred_base = 1;
 721         else
 722                 nr_result++;
 723         if (found_pack) {
 724                 entry->in_pack = found_pack;
 725                 entry->in_pack_offset = found_offset;
 726         }
 727
 728         if (object_ix_hashsz * 3 <= nr_objects * 4)
 729                 rehash_objects();
 730         else
 731                 object_ix[-1 - ix] = nr_objects;
 732
 733         display_progress(progress_state, nr_objects);
 734
 735         if (name && no_try_delta(name))
 736                 entry->no_try_delta = 1;
 737
 738         return 1;
 739 }
 740
 741 struct pbase_tree_cache {
 742         unsigned char sha1[20];
 743         int ref;
 744         int temporary;
 745         void *tree_data;
 746         unsigned long tree_size;
 747 };
 748
 749 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 750 static int pbase_tree_cache_ix(const unsigned char *sha1)
 751 {
 752         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 753 }
 754 static int pbase_tree_cache_ix_incr(int ix)
 755 {
 756         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 757 }
 758
 759 static struct pbase_tree {
 760         struct pbase_tree *next;
 761         /* This is a phony "cache" entry; we are not
 762          * going to evict it nor find it through _get()
 763          * mechanism -- this is for the toplevel node that
 764          * would almost always change with any commit.
 765          */
 766         struct pbase_tree_cache pcache;
 767 } *pbase_tree;
 768
 769 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 770 {
 771         struct pbase_tree_cache *ent, *nent;
 772         void *data;
 773         unsigned long size;
 774         enum object_type type;
 775         int neigh;
 776         int my_ix = pbase_tree_cache_ix(sha1);
 777         int available_ix = -1;
 778
 779         /* pbase-tree-cache acts as a limited hashtable.
 780          * your object will be found at your index or within a few
 781          * slots after that slot if it is cached.
 782          */
 783         for (neigh = 0; neigh < 8; neigh++) {
 784                 ent = pbase_tree_cache[my_ix];
 785                 if (ent && !hashcmp(ent->sha1, sha1)) {
 786                         ent->ref++;
 787                         return ent;
 788                 }
 789                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 790                          ((0 <= available_ix) &&
 791                           (!ent && pbase_tree_cache[available_ix])))
 792                         available_ix = my_ix;
 793                 if (!ent)
 794                         break;
 795                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 796         }
 797
 798         /* Did not find one.  Either we got a bogus request or
 799          * we need to read and perhaps cache.
 800          */
 801         data = read_sha1_file(sha1, &type, &size);
 802         if (!data)
 803                 return NULL;
 804         if (type != OBJ_TREE) {
 805                 free(data);
 806                 return NULL;
 807         }
 808
 809         /* We need to either cache or return a throwaway copy */
 810
 811         if (available_ix < 0)
 812                 ent = NULL;
 813         else {
 814                 ent = pbase_tree_cache[available_ix];
 815                 my_ix = available_ix;
 816         }
 817
 818         if (!ent) {
 819                 nent = xmalloc(sizeof(*nent));
 820                 nent->temporary = (available_ix < 0);
 821         }
 822         else {
 823                 /* evict and reuse */
 824                 free(ent->tree_data);
 825                 nent = ent;
 826         }
 827         hashcpy(nent->sha1, sha1);
 828         nent->tree_data = data;
 829         nent->tree_size = size;
 830         nent->ref = 1;
 831         if (!nent->temporary)
 832                 pbase_tree_cache[my_ix] = nent;
 833         return nent;
 834 }
 835
 836 static void pbase_tree_put(struct pbase_tree_cache *cache)
 837 {
 838         if (!cache->temporary) {
 839                 cache->ref--;
 840                 return;
 841         }
 842         free(cache->tree_data);
 843         free(cache);
 844 }
 845
 846 static int name_cmp_len(const char *name)
 847 {
 848         int i;
 849         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 850                 ;
 851         return i;
 852 }
 853
 854 static void add_pbase_object(struct tree_desc *tree,
 855                              const char *name,
 856                              int cmplen,
 857                              const char *fullname)
 858 {
 859         struct name_entry entry;
 860         int cmp;
 861
 862         while (tree_entry(tree,&entry)) {
 863                 if (S_ISGITLINK(entry.mode))
 864                         continue;
 865                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 866                       memcmp(name, entry.path, cmplen);
 867                 if (cmp > 0)
 868                         continue;
 869                 if (cmp < 0)
 870                         return;
 871                 if (name[cmplen] != '/') {
 872                         add_object_entry(entry.sha1,
 873                                          object_type(entry.mode),
 874                                          fullname, 1);
 875                         return;
 876                 }
 877                 if (S_ISDIR(entry.mode)) {
 878                         struct tree_desc sub;
 879                         struct pbase_tree_cache *tree;
 880                         const char *down = name+cmplen+1;
 881                         int downlen = name_cmp_len(down);
 882
 883                         tree = pbase_tree_get(entry.sha1);
 884                         if (!tree)
 885                                 return;
 886                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 887
 888                         add_pbase_object(&sub, down, downlen, fullname);
 889                         pbase_tree_put(tree);
 890                 }
 891         }
 892 }
 893
 894 static unsigned *done_pbase_paths;
 895 static int done_pbase_paths_num;
 896 static int done_pbase_paths_alloc;
 897 static int done_pbase_path_pos(unsigned hash)
 898 {
 899         int lo = 0;
 900         int hi = done_pbase_paths_num;
 901         while (lo < hi) {
 902                 int mi = (hi + lo) / 2;
 903                 if (done_pbase_paths[mi] == hash)
 904                         return mi;
 905                 if (done_pbase_paths[mi] < hash)
 906                         hi = mi;
 907                 else
 908                         lo = mi + 1;
 909         }
 910         return -lo-1;
 911 }
 912
 913 static int check_pbase_path(unsigned hash)
 914 {
 915         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 916         if (0 <= pos)
 917                 return 1;
 918         pos = -pos - 1;
 919         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 920                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 921                 done_pbase_paths = xrealloc(done_pbase_paths,
 922                                             done_pbase_paths_alloc *
 923                                             sizeof(unsigned));
 924         }
 925         done_pbase_paths_num++;
 926         if (pos < done_pbase_paths_num)
 927                 memmove(done_pbase_paths + pos + 1,
 928                         done_pbase_paths + pos,
 929                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 930         done_pbase_paths[pos] = hash;
 931         return 0;
 932 }
 933
 934 static void add_preferred_base_object(const char *name)
 935 {
 936         struct pbase_tree *it;
 937         int cmplen;
 938         unsigned hash = name_hash(name);
 939
 940         if (!num_preferred_base || check_pbase_path(hash))
 941                 return;
 942
 943         cmplen = name_cmp_len(name);
 944         for (it = pbase_tree; it; it = it->next) {
 945                 if (cmplen == 0) {
 946                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 947                 }
 948                 else {
 949                         struct tree_desc tree;
 950                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 951                         add_pbase_object(&tree, name, cmplen, name);
 952                 }
 953         }
 954 }
 955
 956 static void add_preferred_base(unsigned char *sha1)
 957 {
 958         struct pbase_tree *it;
 959         void *data;
 960         unsigned long size;
 961         unsigned char tree_sha1[20];
 962
 963         if (window <= num_preferred_base++)
 964                 return;
 965
 966         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 967         if (!data)
 968                 return;
 969
 970         for (it = pbase_tree; it; it = it->next) {
 971                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 972                         free(data);
 973                         return;
 974                 }
 975         }
 976
 977         it = xcalloc(1, sizeof(*it));
 978         it->next = pbase_tree;
 979         pbase_tree = it;
 980
 981         hashcpy(it->pcache.sha1, tree_sha1);
 982         it->pcache.tree_data = data;
 983         it->pcache.tree_size = size;
 984 }
 985
 986 static void check_object(struct object_entry *entry)
 987 {
 988         if (entry->in_pack) {
 989                 struct packed_git *p = entry->in_pack;
 990                 struct pack_window *w_curs = NULL;
 991                 const unsigned char *base_ref = NULL;
 992                 struct object_entry *base_entry;
 993                 unsigned long used, used_0;
 994                 unsigned int avail;
 995                 off_t ofs;
 996                 unsigned char *buf, c;
 997
 998                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
 999
1000                 /*
1001                  * We want in_pack_type even if we do not reuse delta
1002                  * since non-delta representations could still be reused.
1003                  */
1004                 used = unpack_object_header_gently(buf, avail,
1005                                                    &entry->in_pack_type,
1006                                                    &entry->size);
1007
1008                 /*
1009                  * Determine if this is a delta and if so whether we can
1010                  * reuse it or not.  Otherwise let's find out as cheaply as
1011                  * possible what the actual type and size for this object is.
1012                  */
1013                 switch (entry->in_pack_type) {
1014                 default:
1015                         /* Not a delta hence we've already got all we need. */
1016                         entry->type = entry->in_pack_type;
1017                         entry->in_pack_header_size = used;
1018                         unuse_pack(&w_curs);
1019                         return;
1020                 case OBJ_REF_DELTA:
1021                         if (reuse_delta && !entry->preferred_base)
1022                                 base_ref = use_pack(p, &w_curs,
1023                                                 entry->in_pack_offset + used, NULL);
1024                         entry->in_pack_header_size = used + 20;
1025                         break;
1026                 case OBJ_OFS_DELTA:
1027                         buf = use_pack(p, &w_curs,
1028                                        entry->in_pack_offset + used, NULL);
1029                         used_0 = 0;
1030                         c = buf[used_0++];
1031                         ofs = c & 127;
1032                         while (c & 128) {
1033                                 ofs += 1;
1034                                 if (!ofs || MSB(ofs, 7))
1035                                         die("delta base offset overflow in pack for %s",
1036                                             sha1_to_hex(entry->idx.sha1));
1037                                 c = buf[used_0++];
1038                                 ofs = (ofs << 7) + (c & 127);
1039                         }
1040                         if (ofs >= entry->in_pack_offset)
1041                                 die("delta base offset out of bound for %s",
1042                                     sha1_to_hex(entry->idx.sha1));
1043                         ofs = entry->in_pack_offset - ofs;
1044                         if (reuse_delta && !entry->preferred_base) {
1045                                 struct revindex_entry *revidx;
1046                                 revidx = find_pack_revindex(p, ofs);
1047                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1048                         }
1049                         entry->in_pack_header_size = used + used_0;
1050                         break;
1051                 }
1052
1053                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1054                         /*
1055                          * If base_ref was set above that means we wish to
1056                          * reuse delta data, and we even found that base
1057                          * in the list of objects we want to pack. Goodie!
1058                          *
1059                          * Depth value does not matter - find_deltas() will
1060                          * never consider reused delta as the base object to
1061                          * deltify other objects against, in order to avoid
1062                          * circular deltas.
1063                          */
1064                         entry->type = entry->in_pack_type;
1065                         entry->delta = base_entry;
1066                         entry->delta_sibling = base_entry->delta_child;
1067                         base_entry->delta_child = entry;
1068                         unuse_pack(&w_curs);
1069                         return;
1070                 }
1071
1072                 if (entry->type) {
1073                         /*
1074                          * This must be a delta and we already know what the
1075                          * final object type is.  Let's extract the actual
1076                          * object size from the delta header.
1077                          */
1078                         entry->size = get_size_from_delta(p, &w_curs,
1079                                         entry->in_pack_offset + entry->in_pack_header_size);
1080                         unuse_pack(&w_curs);
1081                         return;
1082                 }
1083
1084                 /*
1085                  * No choice but to fall back to the recursive delta walk
1086                  * with sha1_object_info() to find about the object type
1087                  * at this point...
1088                  */
1089                 unuse_pack(&w_curs);
1090         }
1091
1092         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1093         if (entry->type < 0)
1094                 die("unable to get type of object %s",
1095                     sha1_to_hex(entry->idx.sha1));
1096 }
1097
1098 static int pack_offset_sort(const void *_a, const void *_b)
1099 {
1100         const struct object_entry *a = *(struct object_entry **)_a;
1101         const struct object_entry *b = *(struct object_entry **)_b;
1102
1103         /* avoid filesystem trashing with loose objects */
1104         if (!a->in_pack && !b->in_pack)
1105                 return hashcmp(a->idx.sha1, b->idx.sha1);
1106
1107         if (a->in_pack < b->in_pack)
1108                 return -1;
1109         if (a->in_pack > b->in_pack)
1110                 return 1;
1111         return a->in_pack_offset < b->in_pack_offset ? -1 :
1112                         (a->in_pack_offset > b->in_pack_offset);
1113 }
1114
1115 static void get_object_details(void)
1116 {
1117         uint32_t i;
1118         struct object_entry **sorted_by_offset;
1119
1120         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1121         for (i = 0; i < nr_objects; i++)
1122                 sorted_by_offset[i] = objects + i;
1123         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1124
1125         for (i = 0; i < nr_objects; i++)
1126                 check_object(sorted_by_offset[i]);
1127
1128         free(sorted_by_offset);
1129 }
1130
1131 /*
1132  * We search for deltas in a list sorted by type, by filename hash, and then
1133  * by size, so that we see progressively smaller and smaller files.
1134  * That's because we prefer deltas to be from the bigger file
1135  * to the smaller -- deletes are potentially cheaper, but perhaps
1136  * more importantly, the bigger file is likely the more recent
1137  * one.  The deepest deltas are therefore the oldest objects which are
1138  * less susceptible to be accessed often.
1139  */
1140 static int type_size_sort(const void *_a, const void *_b)
1141 {
1142         const struct object_entry *a = *(struct object_entry **)_a;
1143         const struct object_entry *b = *(struct object_entry **)_b;
1144
1145         if (a->type > b->type)
1146                 return -1;
1147         if (a->type < b->type)
1148                 return 1;
1149         if (a->hash > b->hash)
1150                 return -1;
1151         if (a->hash < b->hash)
1152                 return 1;
1153         if (a->preferred_base > b->preferred_base)
1154                 return -1;
1155         if (a->preferred_base < b->preferred_base)
1156                 return 1;
1157         if (a->size > b->size)
1158                 return -1;
1159         if (a->size < b->size)
1160                 return 1;
1161         return a < b ? -1 : (a > b);  /* newest first */
1162 }
1163
1164 struct unpacked {
1165         struct object_entry *entry;
1166         void *data;
1167         struct delta_index *index;
1168         unsigned depth;
1169 };
1170
1171 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1172                            unsigned long delta_size)
1173 {
1174         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1175                 return 0;
1176
1177         if (delta_size < cache_max_small_delta_size)
1178                 return 1;
1179
1180         /* cache delta, if objects are large enough compared to delta size */
1181         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1182                 return 1;
1183
1184         return 0;
1185 }
1186
1187 #ifdef THREADED_DELTA_SEARCH
1188
1189 static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1190 #define read_lock()             pthread_mutex_lock(&read_mutex)
1191 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1192
1193 static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1194 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1195 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1196
1197 static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1198 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1199 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1200
1201 #else
1202
1203 #define read_lock()             (void)0
1204 #define read_unlock()           (void)0
1205 #define cache_lock()            (void)0
1206 #define cache_unlock()          (void)0
1207 #define progress_lock()         (void)0
1208 #define progress_unlock()       (void)0
1209
1210 #endif
1211
1212 static int try_delta(struct unpacked *trg, struct unpacked *src,
1213                      unsigned max_depth, unsigned long *mem_usage)
1214 {
1215         struct object_entry *trg_entry = trg->entry;
1216         struct object_entry *src_entry = src->entry;
1217         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1218         unsigned ref_depth;
1219         enum object_type type;
1220         void *delta_buf;
1221
1222         /* Don't bother doing diffs between different types */
1223         if (trg_entry->type != src_entry->type)
1224                 return -1;
1225
1226         /*
1227          * We do not bother to try a delta that we discarded
1228          * on an earlier try, but only when reusing delta data.
1229          */
1230         if (reuse_delta && trg_entry->in_pack &&
1231             trg_entry->in_pack == src_entry->in_pack &&
1232             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1233             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1234                 return 0;
1235
1236         /* Let's not bust the allowed depth. */
1237         if (src->depth >= max_depth)
1238                 return 0;
1239
1240         /* Now some size filtering heuristics. */
1241         trg_size = trg_entry->size;
1242         if (!trg_entry->delta) {
1243                 max_size = trg_size/2 - 20;
1244                 ref_depth = 1;
1245         } else {
1246                 max_size = trg_entry->delta_size;
1247                 ref_depth = trg->depth;
1248         }
1249         max_size = max_size * (max_depth - src->depth) /
1250                                                 (max_depth - ref_depth + 1);
1251         if (max_size == 0)
1252                 return 0;
1253         src_size = src_entry->size;
1254         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1255         if (sizediff >= max_size)
1256                 return 0;
1257         if (trg_size < src_size / 32)
1258                 return 0;
1259
1260         /* Load data if not already done */
1261         if (!trg->data) {
1262                 read_lock();
1263                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1264                 read_unlock();
1265                 if (!trg->data)
1266                         die("object %s cannot be read",
1267                             sha1_to_hex(trg_entry->idx.sha1));
1268                 if (sz != trg_size)
1269                         die("object %s inconsistent object length (%lu vs %lu)",
1270                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1271                 *mem_usage += sz;
1272         }
1273         if (!src->data) {
1274                 read_lock();
1275                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1276                 read_unlock();
1277                 if (!src->data)
1278                         die("object %s cannot be read",
1279                             sha1_to_hex(src_entry->idx.sha1));
1280                 if (sz != src_size)
1281                         die("object %s inconsistent object length (%lu vs %lu)",
1282                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1283                 *mem_usage += sz;
1284         }
1285         if (!src->index) {
1286                 src->index = create_delta_index(src->data, src_size);
1287                 if (!src->index) {
1288                         static int warned = 0;
1289                         if (!warned++)
1290                                 warning("suboptimal pack - out of memory");
1291                         return 0;
1292                 }
1293                 *mem_usage += sizeof_delta_index(src->index);
1294         }
1295
1296         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1297         if (!delta_buf)
1298                 return 0;
1299
1300         if (trg_entry->delta) {
1301                 /* Prefer only shallower same-sized deltas. */
1302                 if (delta_size == trg_entry->delta_size &&
1303                     src->depth + 1 >= trg->depth) {
1304                         free(delta_buf);
1305                         return 0;
1306                 }
1307         }
1308
1309         /*
1310          * Handle memory allocation outside of the cache
1311          * accounting lock.  Compiler will optimize the strangeness
1312          * away when THREADED_DELTA_SEARCH is not defined.
1313          */
1314         free(trg_entry->delta_data);
1315         cache_lock();
1316         if (trg_entry->delta_data) {
1317                 delta_cache_size -= trg_entry->delta_size;
1318                 trg_entry->delta_data = NULL;
1319         }
1320         if (delta_cacheable(src_size, trg_size, delta_size)) {
1321                 delta_cache_size += delta_size;
1322                 cache_unlock();
1323                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1324         } else {
1325                 cache_unlock();
1326                 free(delta_buf);
1327         }
1328
1329         trg_entry->delta = src_entry;
1330         trg_entry->delta_size = delta_size;
1331         trg->depth = src->depth + 1;
1332
1333         return 1;
1334 }
1335
1336 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1337 {
1338         struct object_entry *child = me->delta_child;
1339         unsigned int m = n;
1340         while (child) {
1341                 unsigned int c = check_delta_limit(child, n + 1);
1342                 if (m < c)
1343                         m = c;
1344                 child = child->delta_sibling;
1345         }
1346         return m;
1347 }
1348
1349 static unsigned long free_unpacked(struct unpacked *n)
1350 {
1351         unsigned long freed_mem = sizeof_delta_index(n->index);
1352         free_delta_index(n->index);
1353         n->index = NULL;
1354         if (n->data) {
1355                 freed_mem += n->entry->size;
1356                 free(n->data);
1357                 n->data = NULL;
1358         }
1359         n->entry = NULL;
1360         n->depth = 0;
1361         return freed_mem;
1362 }
1363
1364 static void find_deltas(struct object_entry **list, unsigned *list_size,
1365                         int window, int depth, unsigned *processed)
1366 {
1367         uint32_t i, idx = 0, count = 0;
1368         unsigned int array_size = window * sizeof(struct unpacked);
1369         struct unpacked *array;
1370         unsigned long mem_usage = 0;
1371
1372         array = xmalloc(array_size);
1373         memset(array, 0, array_size);
1374
1375         for (;;) {
1376                 struct object_entry *entry = *list++;
1377                 struct unpacked *n = array + idx;
1378                 int j, max_depth, best_base = -1;
1379
1380                 progress_lock();
1381                 if (!*list_size) {
1382                         progress_unlock();
1383                         break;
1384                 }
1385                 (*list_size)--;
1386                 if (!entry->preferred_base) {
1387                         (*processed)++;
1388                         display_progress(progress_state, *processed);
1389                 }
1390                 progress_unlock();
1391
1392                 mem_usage -= free_unpacked(n);
1393                 n->entry = entry;
1394
1395                 while (window_memory_limit &&
1396                        mem_usage > window_memory_limit &&
1397                        count > 1) {
1398                         uint32_t tail = (idx + window - count) % window;
1399                         mem_usage -= free_unpacked(array + tail);
1400                         count--;
1401                 }
1402
1403                 /* We do not compute delta to *create* objects we are not
1404                  * going to pack.
1405                  */
1406                 if (entry->preferred_base)
1407                         goto next;
1408
1409                 /*
1410                  * If the current object is at pack edge, take the depth the
1411                  * objects that depend on the current object into account
1412                  * otherwise they would become too deep.
1413                  */
1414                 max_depth = depth;
1415                 if (entry->delta_child) {
1416                         max_depth -= check_delta_limit(entry, 0);
1417                         if (max_depth <= 0)
1418                                 goto next;
1419                 }
1420
1421                 j = window;
1422                 while (--j > 0) {
1423                         int ret;
1424                         uint32_t other_idx = idx + j;
1425                         struct unpacked *m;
1426                         if (other_idx >= window)
1427                                 other_idx -= window;
1428                         m = array + other_idx;
1429                         if (!m->entry)
1430                                 break;
1431                         ret = try_delta(n, m, max_depth, &mem_usage);
1432                         if (ret < 0)
1433                                 break;
1434                         else if (ret > 0)
1435                                 best_base = other_idx;
1436                 }
1437
1438                 /*
1439                  * If we decided to cache the delta data, then it is best
1440                  * to compress it right away.  First because we have to do
1441                  * it anyway, and doing it here while we're threaded will
1442                  * save a lot of time in the non threaded write phase,
1443                  * as well as allow for caching more deltas within
1444                  * the same cache size limit.
1445                  * ...
1446                  * But only if not writing to stdout, since in that case
1447                  * the network is most likely throttling writes anyway,
1448                  * and therefore it is best to go to the write phase ASAP
1449                  * instead, as we can afford spending more time compressing
1450                  * between writes at that moment.
1451                  */
1452                 if (entry->delta_data && !pack_to_stdout) {
1453                         entry->z_delta_size = do_compress(&entry->delta_data,
1454                                                           entry->delta_size);
1455                         cache_lock();
1456                         delta_cache_size -= entry->delta_size;
1457                         delta_cache_size += entry->z_delta_size;
1458                         cache_unlock();
1459                 }
1460
1461                 /* if we made n a delta, and if n is already at max
1462                  * depth, leaving it in the window is pointless.  we
1463                  * should evict it first.
1464                  */
1465                 if (entry->delta && max_depth <= n->depth)
1466                         continue;
1467
1468                 /*
1469                  * Move the best delta base up in the window, after the
1470                  * currently deltified object, to keep it longer.  It will
1471                  * be the first base object to be attempted next.
1472                  */
1473                 if (entry->delta) {
1474                         struct unpacked swap = array[best_base];
1475                         int dist = (window + idx - best_base) % window;
1476                         int dst = best_base;
1477                         while (dist--) {
1478                                 int src = (dst + 1) % window;
1479                                 array[dst] = array[src];
1480                                 dst = src;
1481                         }
1482                         array[dst] = swap;
1483                 }
1484
1485                 next:
1486                 idx++;
1487                 if (count + 1 < window)
1488                         count++;
1489                 if (idx >= window)
1490                         idx = 0;
1491         }
1492
1493         for (i = 0; i < window; ++i) {
1494                 free_delta_index(array[i].index);
1495                 free(array[i].data);
1496         }
1497         free(array);
1498 }
1499
1500 #ifdef THREADED_DELTA_SEARCH
1501
1502 /*
1503  * The main thread waits on the condition that (at least) one of the workers
1504  * has stopped working (which is indicated in the .working member of
1505  * struct thread_params).
1506  * When a work thread has completed its work, it sets .working to 0 and
1507  * signals the main thread and waits on the condition that .data_ready
1508  * becomes 1.
1509  */
1510
1511 struct thread_params {
1512         pthread_t thread;
1513         struct object_entry **list;
1514         unsigned list_size;
1515         unsigned remaining;
1516         int window;
1517         int depth;
1518         int working;
1519         int data_ready;
1520         pthread_mutex_t mutex;
1521         pthread_cond_t cond;
1522         unsigned *processed;
1523 };
1524
1525 static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
1526
1527 static void *threaded_find_deltas(void *arg)
1528 {
1529         struct thread_params *me = arg;
1530
1531         while (me->remaining) {
1532                 find_deltas(me->list, &me->remaining,
1533                             me->window, me->depth, me->processed);
1534
1535                 progress_lock();
1536                 me->working = 0;
1537                 pthread_cond_signal(&progress_cond);
1538                 progress_unlock();
1539
1540                 /*
1541                  * We must not set ->data_ready before we wait on the
1542                  * condition because the main thread may have set it to 1
1543                  * before we get here. In order to be sure that new
1544                  * work is available if we see 1 in ->data_ready, it
1545                  * was initialized to 0 before this thread was spawned
1546                  * and we reset it to 0 right away.
1547                  */
1548                 pthread_mutex_lock(&me->mutex);
1549                 while (!me->data_ready)
1550                         pthread_cond_wait(&me->cond, &me->mutex);
1551                 me->data_ready = 0;
1552                 pthread_mutex_unlock(&me->mutex);
1553         }
1554         /* leave ->working 1 so that this doesn't get more work assigned */
1555         return NULL;
1556 }
1557
1558 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1559                            int window, int depth, unsigned *processed)
1560 {
1561         struct thread_params p[delta_search_threads];
1562         int i, ret, active_threads = 0;
1563
1564         if (delta_search_threads <= 1) {
1565                 find_deltas(list, &list_size, window, depth, processed);
1566                 return;
1567         }
1568
1569         /* Partition the work amongst work threads. */
1570         for (i = 0; i < delta_search_threads; i++) {
1571                 unsigned sub_size = list_size / (delta_search_threads - i);
1572
1573                 p[i].window = window;
1574                 p[i].depth = depth;
1575                 p[i].processed = processed;
1576                 p[i].working = 1;
1577                 p[i].data_ready = 0;
1578
1579                 /* try to split chunks on "path" boundaries */
1580                 while (sub_size && sub_size < list_size &&
1581                        list[sub_size]->hash &&
1582                        list[sub_size]->hash == list[sub_size-1]->hash)
1583                         sub_size++;
1584
1585                 p[i].list = list;
1586                 p[i].list_size = sub_size;
1587                 p[i].remaining = sub_size;
1588
1589                 list += sub_size;
1590                 list_size -= sub_size;
1591         }
1592
1593         /* Start work threads. */
1594         for (i = 0; i < delta_search_threads; i++) {
1595                 if (!p[i].list_size)
1596                         continue;
1597                 pthread_mutex_init(&p[i].mutex, NULL);
1598                 pthread_cond_init(&p[i].cond, NULL);
1599                 ret = pthread_create(&p[i].thread, NULL,
1600                                      threaded_find_deltas, &p[i]);
1601                 if (ret)
1602                         die("unable to create thread: %s", strerror(ret));
1603                 active_threads++;
1604         }
1605
1606         /*
1607          * Now let's wait for work completion.  Each time a thread is done
1608          * with its work, we steal half of the remaining work from the
1609          * thread with the largest number of unprocessed objects and give
1610          * it to that newly idle thread.  This ensure good load balancing
1611          * until the remaining object list segments are simply too short
1612          * to be worth splitting anymore.
1613          */
1614         while (active_threads) {
1615                 struct thread_params *target = NULL;
1616                 struct thread_params *victim = NULL;
1617                 unsigned sub_size = 0;
1618
1619                 progress_lock();
1620                 for (;;) {
1621                         for (i = 0; !target && i < delta_search_threads; i++)
1622                                 if (!p[i].working)
1623                                         target = &p[i];
1624                         if (target)
1625                                 break;
1626                         pthread_cond_wait(&progress_cond, &progress_mutex);
1627                 }
1628
1629                 for (i = 0; i < delta_search_threads; i++)
1630                         if (p[i].remaining > 2*window &&
1631                             (!victim || victim->remaining < p[i].remaining))
1632                                 victim = &p[i];
1633                 if (victim) {
1634                         sub_size = victim->remaining / 2;
1635                         list = victim->list + victim->list_size - sub_size;
1636                         while (sub_size && list[0]->hash &&
1637                                list[0]->hash == list[-1]->hash) {
1638                                 list++;
1639                                 sub_size--;
1640                         }
1641                         if (!sub_size) {
1642                                 /*
1643                                  * It is possible for some "paths" to have
1644                                  * so many objects that no hash boundary
1645                                  * might be found.  Let's just steal the
1646                                  * exact half in that case.
1647                                  */
1648                                 sub_size = victim->remaining / 2;
1649                                 list -= sub_size;
1650                         }
1651                         target->list = list;
1652                         victim->list_size -= sub_size;
1653                         victim->remaining -= sub_size;
1654                 }
1655                 target->list_size = sub_size;
1656                 target->remaining = sub_size;
1657                 target->working = 1;
1658                 progress_unlock();
1659
1660                 pthread_mutex_lock(&target->mutex);
1661                 target->data_ready = 1;
1662                 pthread_cond_signal(&target->cond);
1663                 pthread_mutex_unlock(&target->mutex);
1664
1665                 if (!sub_size) {
1666                         pthread_join(target->thread, NULL);
1667                         pthread_cond_destroy(&target->cond);
1668                         pthread_mutex_destroy(&target->mutex);
1669                         active_threads--;
1670                 }
1671         }
1672 }
1673
1674 #else
1675 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1676 #endif
1677
1678 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1679 {
1680         unsigned char peeled[20];
1681
1682         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1683             !peel_ref(path, peeled)        && /* peelable? */
1684             !is_null_sha1(peeled)          && /* annotated tag? */
1685             locate_object_entry(peeled))      /* object packed? */
1686                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1687         return 0;
1688 }
1689
1690 static void prepare_pack(int window, int depth)
1691 {
1692         struct object_entry **delta_list;
1693         uint32_t i, nr_deltas;
1694         unsigned n;
1695
1696         get_object_details();
1697
1698         if (!nr_objects || !window || !depth)
1699                 return;
1700
1701         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1702         nr_deltas = n = 0;
1703
1704         for (i = 0; i < nr_objects; i++) {
1705                 struct object_entry *entry = objects + i;
1706
1707                 if (entry->delta)
1708                         /* This happens if we decided to reuse existing
1709                          * delta from a pack.  "reuse_delta &&" is implied.
1710                          */
1711                         continue;
1712
1713                 if (entry->size < 50)
1714                         continue;
1715
1716                 if (entry->no_try_delta)
1717                         continue;
1718
1719                 if (!entry->preferred_base)
1720                         nr_deltas++;
1721
1722                 delta_list[n++] = entry;
1723         }
1724
1725         if (nr_deltas && n > 1) {
1726                 unsigned nr_done = 0;
1727                 if (progress)
1728                         progress_state = start_progress("Compressing objects",
1729                                                         nr_deltas);
1730                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1731                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1732                 stop_progress(&progress_state);
1733                 if (nr_done != nr_deltas)
1734                         die("inconsistency with delta count");
1735         }
1736         free(delta_list);
1737 }
1738
1739 static int git_pack_config(const char *k, const char *v, void *cb)
1740 {
1741         if(!strcmp(k, "pack.window")) {
1742                 window = git_config_int(k, v);
1743                 return 0;
1744         }
1745         if (!strcmp(k, "pack.windowmemory")) {
1746                 window_memory_limit = git_config_ulong(k, v);
1747                 return 0;
1748         }
1749         if (!strcmp(k, "pack.depth")) {
1750                 depth = git_config_int(k, v);
1751                 return 0;
1752         }
1753         if (!strcmp(k, "pack.compression")) {
1754                 int level = git_config_int(k, v);
1755                 if (level == -1)
1756                         level = Z_DEFAULT_COMPRESSION;
1757                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1758                         die("bad pack compression level %d", level);
1759                 pack_compression_level = level;
1760                 pack_compression_seen = 1;
1761                 return 0;
1762         }
1763         if (!strcmp(k, "pack.deltacachesize")) {
1764                 max_delta_cache_size = git_config_int(k, v);
1765                 return 0;
1766         }
1767         if (!strcmp(k, "pack.deltacachelimit")) {
1768                 cache_max_small_delta_size = git_config_int(k, v);
1769                 return 0;
1770         }
1771         if (!strcmp(k, "pack.threads")) {
1772                 delta_search_threads = git_config_int(k, v);
1773                 if (delta_search_threads < 0)
1774                         die("invalid number of threads specified (%d)",
1775                             delta_search_threads);
1776 #ifndef THREADED_DELTA_SEARCH
1777                 if (delta_search_threads != 1)
1778                         warning("no threads support, ignoring %s", k);
1779 #endif
1780                 return 0;
1781         }
1782         if (!strcmp(k, "pack.indexversion")) {
1783                 pack_idx_default_version = git_config_int(k, v);
1784                 if (pack_idx_default_version > 2)
1785                         die("bad pack.indexversion=%"PRIu32,
1786                                 pack_idx_default_version);
1787                 return 0;
1788         }
1789         if (!strcmp(k, "pack.packsizelimit")) {
1790                 pack_size_limit_cfg = git_config_ulong(k, v);
1791                 return 0;
1792         }
1793         return git_default_config(k, v, cb);
1794 }
1795
1796 static void read_object_list_from_stdin(void)
1797 {
1798         char line[40 + 1 + PATH_MAX + 2];
1799         unsigned char sha1[20];
1800
1801         for (;;) {
1802                 if (!fgets(line, sizeof(line), stdin)) {
1803                         if (feof(stdin))
1804                                 break;
1805                         if (!ferror(stdin))
1806                                 die("fgets returned NULL, not EOF, not error!");
1807                         if (errno != EINTR)
1808                                 die("fgets: %s", strerror(errno));
1809                         clearerr(stdin);
1810                         continue;
1811                 }
1812                 if (line[0] == '-') {
1813                         if (get_sha1_hex(line+1, sha1))
1814                                 die("expected edge sha1, got garbage:\n %s",
1815                                     line);
1816                         add_preferred_base(sha1);
1817                         continue;
1818                 }
1819                 if (get_sha1_hex(line, sha1))
1820                         die("expected sha1, got garbage:\n %s", line);
1821
1822                 add_preferred_base_object(line+41);
1823                 add_object_entry(sha1, 0, line+41, 0);
1824         }
1825 }
1826
1827 #define OBJECT_ADDED (1u<<20)
1828
1829 static void show_commit(struct commit *commit)
1830 {
1831         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1832         commit->object.flags |= OBJECT_ADDED;
1833 }
1834
1835 static void show_object(struct object_array_entry *p)
1836 {
1837         add_preferred_base_object(p->name);
1838         add_object_entry(p->item->sha1, p->item->type, p->name, 0);
1839         p->item->flags |= OBJECT_ADDED;
1840 }
1841
1842 static void show_edge(struct commit *commit)
1843 {
1844         add_preferred_base(commit->object.sha1);
1845 }
1846
1847 struct in_pack_object {
1848         off_t offset;
1849         struct object *object;
1850 };
1851
1852 struct in_pack {
1853         int alloc;
1854         int nr;
1855         struct in_pack_object *array;
1856 };
1857
1858 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1859 {
1860         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1861         in_pack->array[in_pack->nr].object = object;
1862         in_pack->nr++;
1863 }
1864
1865 /*
1866  * Compare the objects in the offset order, in order to emulate the
1867  * "git-rev-list --objects" output that produced the pack originally.
1868  */
1869 static int ofscmp(const void *a_, const void *b_)
1870 {
1871         struct in_pack_object *a = (struct in_pack_object *)a_;
1872         struct in_pack_object *b = (struct in_pack_object *)b_;
1873
1874         if (a->offset < b->offset)
1875                 return -1;
1876         else if (a->offset > b->offset)
1877                 return 1;
1878         else
1879                 return hashcmp(a->object->sha1, b->object->sha1);
1880 }
1881
1882 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1883 {
1884         struct packed_git *p;
1885         struct in_pack in_pack;
1886         uint32_t i;
1887
1888         memset(&in_pack, 0, sizeof(in_pack));
1889
1890         for (p = packed_git; p; p = p->next) {
1891                 const unsigned char *sha1;
1892                 struct object *o;
1893
1894                 for (i = 0; i < revs->num_ignore_packed; i++) {
1895                         if (matches_pack_name(p, revs->ignore_packed[i]))
1896                                 break;
1897                 }
1898                 if (revs->num_ignore_packed <= i)
1899                         continue;
1900                 if (open_pack_index(p))
1901                         die("cannot open pack index");
1902
1903                 ALLOC_GROW(in_pack.array,
1904                            in_pack.nr + p->num_objects,
1905                            in_pack.alloc);
1906
1907                 for (i = 0; i < p->num_objects; i++) {
1908                         sha1 = nth_packed_object_sha1(p, i);
1909                         o = lookup_unknown_object(sha1);
1910                         if (!(o->flags & OBJECT_ADDED))
1911                                 mark_in_pack_object(o, p, &in_pack);
1912                         o->flags |= OBJECT_ADDED;
1913                 }
1914         }
1915
1916         if (in_pack.nr) {
1917                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
1918                       ofscmp);
1919                 for (i = 0; i < in_pack.nr; i++) {
1920                         struct object *o = in_pack.array[i].object;
1921                         add_object_entry(o->sha1, o->type, "", 0);
1922                 }
1923         }
1924         free(in_pack.array);
1925 }
1926
1927 static void loosen_unused_packed_objects(struct rev_info *revs)
1928 {
1929         struct packed_git *p;
1930         uint32_t i;
1931         const unsigned char *sha1;
1932
1933         for (p = packed_git; p; p = p->next) {
1934                 for (i = 0; i < revs->num_ignore_packed; i++) {
1935                         if (matches_pack_name(p, revs->ignore_packed[i]))
1936                                 break;
1937                 }
1938                 if (revs->num_ignore_packed <= i)
1939                         continue;
1940
1941                 if (open_pack_index(p))
1942                         die("cannot open pack index");
1943
1944                 for (i = 0; i < p->num_objects; i++) {
1945                         sha1 = nth_packed_object_sha1(p, i);
1946                         if (!locate_object_entry(sha1))
1947                                 if (force_object_loose(sha1, p->mtime))
1948                                         die("unable to force loose object");
1949                 }
1950         }
1951 }
1952
1953 static void get_object_list(int ac, const char **av)
1954 {
1955         struct rev_info revs;
1956         char line[1000];
1957         int flags = 0;
1958
1959         init_revisions(&revs, NULL);
1960         save_commit_buffer = 0;
1961         setup_revisions(ac, av, &revs, NULL);
1962
1963         while (fgets(line, sizeof(line), stdin) != NULL) {
1964                 int len = strlen(line);
1965                 if (len && line[len - 1] == '\n')
1966                         line[--len] = 0;
1967                 if (!len)
1968                         break;
1969                 if (*line == '-') {
1970                         if (!strcmp(line, "--not")) {
1971                                 flags ^= UNINTERESTING;
1972                                 continue;
1973                         }
1974                         die("not a rev '%s'", line);
1975                 }
1976                 if (handle_revision_arg(line, &revs, flags, 1))
1977                         die("bad revision '%s'", line);
1978         }
1979
1980         if (prepare_revision_walk(&revs))
1981                 die("revision walk setup failed");
1982         mark_edges_uninteresting(revs.commits, &revs, show_edge);
1983         traverse_commit_list(&revs, show_commit, show_object);
1984
1985         if (keep_unreachable)
1986                 add_objects_in_unpacked_packs(&revs);
1987         if (unpack_unreachable)
1988                 loosen_unused_packed_objects(&revs);
1989 }
1990
1991 static int adjust_perm(const char *path, mode_t mode)
1992 {
1993         if (chmod(path, mode))
1994                 return -1;
1995         return adjust_shared_perm(path);
1996 }
1997
1998 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
1999 {
2000         int use_internal_rev_list = 0;
2001         int thin = 0;
2002         uint32_t i;
2003         const char **rp_av;
2004         int rp_ac_alloc = 64;
2005         int rp_ac;
2006
2007         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2008
2009         rp_av[0] = "pack-objects";
2010         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2011         rp_ac = 2;
2012
2013         git_config(git_pack_config, NULL);
2014         if (!pack_compression_seen && core_compression_seen)
2015                 pack_compression_level = core_compression_level;
2016
2017         progress = isatty(2);
2018         for (i = 1; i < argc; i++) {
2019                 const char *arg = argv[i];
2020
2021                 if (*arg != '-')
2022                         break;
2023
2024                 if (!strcmp("--non-empty", arg)) {
2025                         non_empty = 1;
2026                         continue;
2027                 }
2028                 if (!strcmp("--local", arg)) {
2029                         local = 1;
2030                         continue;
2031                 }
2032                 if (!strcmp("--incremental", arg)) {
2033                         incremental = 1;
2034                         continue;
2035                 }
2036                 if (!prefixcmp(arg, "--compression=")) {
2037                         char *end;
2038                         int level = strtoul(arg+14, &end, 0);
2039                         if (!arg[14] || *end)
2040                                 usage(pack_usage);
2041                         if (level == -1)
2042                                 level = Z_DEFAULT_COMPRESSION;
2043                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2044                                 die("bad pack compression level %d", level);
2045                         pack_compression_level = level;
2046                         continue;
2047                 }
2048                 if (!prefixcmp(arg, "--max-pack-size=")) {
2049                         char *end;
2050                         pack_size_limit_cfg = 0;
2051                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2052                         if (!arg[16] || *end)
2053                                 usage(pack_usage);
2054                         continue;
2055                 }
2056                 if (!prefixcmp(arg, "--window=")) {
2057                         char *end;
2058                         window = strtoul(arg+9, &end, 0);
2059                         if (!arg[9] || *end)
2060                                 usage(pack_usage);
2061                         continue;
2062                 }
2063                 if (!prefixcmp(arg, "--window-memory=")) {
2064                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2065                                 usage(pack_usage);
2066                         continue;
2067                 }
2068                 if (!prefixcmp(arg, "--threads=")) {
2069                         char *end;
2070                         delta_search_threads = strtoul(arg+10, &end, 0);
2071                         if (!arg[10] || *end || delta_search_threads < 0)
2072                                 usage(pack_usage);
2073 #ifndef THREADED_DELTA_SEARCH
2074                         if (delta_search_threads != 1)
2075                                 warning("no threads support, "
2076                                         "ignoring %s", arg);
2077 #endif
2078                         continue;
2079                 }
2080                 if (!prefixcmp(arg, "--depth=")) {
2081                         char *end;
2082                         depth = strtoul(arg+8, &end, 0);
2083                         if (!arg[8] || *end)
2084                                 usage(pack_usage);
2085                         continue;
2086                 }
2087                 if (!strcmp("--progress", arg)) {
2088                         progress = 1;
2089                         continue;
2090                 }
2091                 if (!strcmp("--all-progress", arg)) {
2092                         progress = 2;
2093                         continue;
2094                 }
2095                 if (!strcmp("-q", arg)) {
2096                         progress = 0;
2097                         continue;
2098                 }
2099                 if (!strcmp("--no-reuse-delta", arg)) {
2100                         reuse_delta = 0;
2101                         continue;
2102                 }
2103                 if (!strcmp("--no-reuse-object", arg)) {
2104                         reuse_object = reuse_delta = 0;
2105                         continue;
2106                 }
2107                 if (!strcmp("--delta-base-offset", arg)) {
2108                         allow_ofs_delta = 1;
2109                         continue;
2110                 }
2111                 if (!strcmp("--stdout", arg)) {
2112                         pack_to_stdout = 1;
2113                         continue;
2114                 }
2115                 if (!strcmp("--revs", arg)) {
2116                         use_internal_rev_list = 1;
2117                         continue;
2118                 }
2119                 if (!strcmp("--keep-unreachable", arg)) {
2120                         keep_unreachable = 1;
2121                         continue;
2122                 }
2123                 if (!strcmp("--unpack-unreachable", arg)) {
2124                         unpack_unreachable = 1;
2125                         continue;
2126                 }
2127                 if (!strcmp("--include-tag", arg)) {
2128                         include_tag = 1;
2129                         continue;
2130                 }
2131                 if (!strcmp("--unpacked", arg) ||
2132                     !prefixcmp(arg, "--unpacked=") ||
2133                     !strcmp("--reflog", arg) ||
2134                     !strcmp("--all", arg)) {
2135                         use_internal_rev_list = 1;
2136                         if (rp_ac >= rp_ac_alloc - 1) {
2137                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2138                                 rp_av = xrealloc(rp_av,
2139                                                  rp_ac_alloc * sizeof(*rp_av));
2140                         }
2141                         rp_av[rp_ac++] = arg;
2142                         continue;
2143                 }
2144                 if (!strcmp("--thin", arg)) {
2145                         use_internal_rev_list = 1;
2146                         thin = 1;
2147                         rp_av[1] = "--objects-edge";
2148                         continue;
2149                 }
2150                 if (!prefixcmp(arg, "--index-version=")) {
2151                         char *c;
2152                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2153                         if (pack_idx_default_version > 2)
2154                                 die("bad %s", arg);
2155                         if (*c == ',')
2156                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2157                         if (*c || pack_idx_off32_limit & 0x80000000)
2158                                 die("bad %s", arg);
2159                         continue;
2160                 }
2161                 usage(pack_usage);
2162         }
2163
2164         /* Traditionally "pack-objects [options] base extra" failed;
2165          * we would however want to take refs parameter that would
2166          * have been given to upstream rev-list ourselves, which means
2167          * we somehow want to say what the base name is.  So the
2168          * syntax would be:
2169          *
2170          * pack-objects [options] base <refs...>
2171          *
2172          * in other words, we would treat the first non-option as the
2173          * base_name and send everything else to the internal revision
2174          * walker.
2175          */
2176
2177         if (!pack_to_stdout)
2178                 base_name = argv[i++];
2179
2180         if (pack_to_stdout != !base_name)
2181                 usage(pack_usage);
2182
2183         if (!pack_to_stdout && !pack_size_limit)
2184                 pack_size_limit = pack_size_limit_cfg;
2185
2186         if (pack_to_stdout && pack_size_limit)
2187                 die("--max-pack-size cannot be used to build a pack for transfer.");
2188
2189         if (!pack_to_stdout && thin)
2190                 die("--thin cannot be used to build an indexable pack.");
2191
2192         if (keep_unreachable && unpack_unreachable)
2193                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2194
2195 #ifdef THREADED_DELTA_SEARCH
2196         if (!delta_search_threads)      /* --threads=0 means autodetect */
2197                 delta_search_threads = online_cpus();
2198 #endif
2199
2200         prepare_packed_git();
2201
2202         if (progress)
2203                 progress_state = start_progress("Counting objects", 0);
2204         if (!use_internal_rev_list)
2205                 read_object_list_from_stdin();
2206         else {
2207                 rp_av[rp_ac] = NULL;
2208                 get_object_list(rp_ac, rp_av);
2209         }
2210         if (include_tag && nr_result)
2211                 for_each_ref(add_ref_tag, NULL);
2212         stop_progress(&progress_state);
2213
2214         if (non_empty && !nr_result)
2215                 return 0;
2216         if (nr_result)
2217                 prepare_pack(window, depth);
2218         write_pack_file();
2219         if (progress)
2220                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2221                         " reused %"PRIu32" (delta %"PRIu32")\n",
2222                         written, written_delta, reused, reused_delta);
2223         return 0;
2224 }