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

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "attr.h"
   4 #include "object.h"
   5 #include "blob.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "tree.h"
   9 #include "delta.h"
  10 #include "pack.h"
  11 #include "pack-revindex.h"
  12 #include "csum-file.h"
  13 #include "tree-walk.h"
  14 #include "diff.h"
  15 #include "revision.h"
  16 #include "list-objects.h"
  17 #include "progress.h"
  18 #include "refs.h"
  19
  20 #ifdef THREADED_DELTA_SEARCH
  21 #include "thread-utils.h"
  22 #include <pthread.h>
  23 #endif
  24
  25 static const char pack_usage[] = "\
  26 git-pack-objects [{ -q | --progress | --all-progress }] \n\
  27         [--max-pack-size=N] [--local] [--incremental] \n\
  28         [--window=N] [--window-memory=N] [--depth=N] \n\
  29         [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
  30         [--threads=N] [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
  31         [--stdout | base-name] [--include-tag] \n\
  32         [--keep-unreachable | --unpack-unreachable] \n\
  33         [<ref-list | <object-list]";
  34
  35 struct object_entry {
  36         struct pack_idx_entry idx;
  37         unsigned long size;     /* uncompressed size */
  38         struct packed_git *in_pack;     /* already in pack */
  39         off_t in_pack_offset;
  40         struct object_entry *delta;     /* delta base object */
  41         struct object_entry *delta_child; /* deltified objects who bases me */
  42         struct object_entry *delta_sibling; /* other deltified objects who
  43                                              * uses the same base as me
  44                                              */
  45         void *delta_data;       /* cached delta (uncompressed) */
  46         unsigned long delta_size;       /* delta data size (uncompressed) */
  47         unsigned long z_delta_size;     /* delta data size (compressed) */
  48         unsigned int hash;      /* name hint hash */
  49         enum object_type type;
  50         enum object_type in_pack_type;  /* could be delta */
  51         unsigned char in_pack_header_size;
  52         unsigned char preferred_base; /* we do not pack this, but is available
  53                                        * to be used as the base object to delta
  54                                        * objects against.
  55                                        */
  56         unsigned char no_try_delta;
  57 };
  58
  59 /*
  60  * Objects we are going to pack are collected in objects array (dynamically
  61  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  62  * in the order we see -- typically rev-list --objects order that gives us
  63  * nice "minimum seek" order.
  64  */
  65 static struct object_entry *objects;
  66 static struct pack_idx_entry **written_list;
  67 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
  68
  69 static int non_empty;
  70 static int reuse_delta = 1, reuse_object = 1;
  71 static int keep_unreachable, unpack_unreachable, include_tag;
  72 static int local;
  73 static int incremental;
  74 static int 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 off_t 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 offset;
 422
 423         /* if we are deltified, write out base object first. */
 424         if (e->delta) {
 425                 offset = write_one(f, e->delta, offset);
 426                 if (!offset)
 427                         return 0;
 428         }
 429
 430         e->idx.offset = offset;
 431         size = write_object(f, e, offset);
 432         if (!size) {
 433                 e->idx.offset = 0;
 434                 return 0;
 435         }
 436         written_list[nr_written++] = &e->idx;
 437
 438         /* make sure off_t is sufficiently large not to wrap */
 439         if (offset > offset + size)
 440                 die("pack too large for current definition of off_t");
 441         return offset + size;
 442 }
 443
 444 /* forward declaration for write_pack_file */
 445 static int adjust_perm(const char *path, mode_t mode);
 446
 447 static void write_pack_file(void)
 448 {
 449         uint32_t i = 0, j;
 450         struct sha1file *f;
 451         off_t offset, offset_one, last_obj_offset = 0;
 452         struct pack_header hdr;
 453         uint32_t nr_remaining = nr_result;
 454         time_t last_mtime = 0;
 455
 456         if (progress > pack_to_stdout)
 457                 progress_state = start_progress("Writing objects", nr_result);
 458         written_list = xmalloc(nr_objects * sizeof(*written_list));
 459
 460         do {
 461                 unsigned char sha1[20];
 462                 char *pack_tmp_name = NULL;
 463
 464                 if (pack_to_stdout) {
 465                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 466                 } else {
 467                         char tmpname[PATH_MAX];
 468                         int fd;
 469                         snprintf(tmpname, sizeof(tmpname),
 470                                  "%s/tmp_pack_XXXXXX", get_object_directory());
 471                         fd = xmkstemp(tmpname);
 472                         pack_tmp_name = xstrdup(tmpname);
 473                         f = sha1fd(fd, pack_tmp_name);
 474                 }
 475
 476                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
 477                 hdr.hdr_version = htonl(PACK_VERSION);
 478                 hdr.hdr_entries = htonl(nr_remaining);
 479                 sha1write(f, &hdr, sizeof(hdr));
 480                 offset = sizeof(hdr);
 481                 nr_written = 0;
 482                 for (; i < nr_objects; i++) {
 483                         last_obj_offset = offset;
 484                         offset_one = write_one(f, objects + i, offset);
 485                         if (!offset_one)
 486                                 break;
 487                         offset = offset_one;
 488                         display_progress(progress_state, written);
 489                 }
 490
 491                 /*
 492                  * Did we write the wrong # entries in the header?
 493                  * If so, rewrite it like in fast-import
 494                  */
 495                 if (pack_to_stdout) {
 496                         sha1close(f, sha1, CSUM_CLOSE);
 497                 } else if (nr_written == nr_remaining) {
 498                         sha1close(f, sha1, CSUM_FSYNC);
 499                 } else {
 500                         int fd = sha1close(f, NULL, 0);
 501                         fixup_pack_header_footer(fd, sha1, pack_tmp_name, nr_written);
 502                         fsync_or_die(fd, pack_tmp_name);
 503                         close(fd);
 504                 }
 505
 506                 if (!pack_to_stdout) {
 507                         mode_t mode = umask(0);
 508                         struct stat st;
 509                         char *idx_tmp_name, tmpname[PATH_MAX];
 510
 511                         umask(mode);
 512                         mode = 0444 & ~mode;
 513
 514                         idx_tmp_name = write_idx_file(NULL, written_list,
 515                                                       nr_written, sha1);
 516
 517                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 518                                  base_name, sha1_to_hex(sha1));
 519                         if (adjust_perm(pack_tmp_name, mode))
 520                                 die("unable to make temporary pack file readable: %s",
 521                                     strerror(errno));
 522                         if (rename(pack_tmp_name, tmpname))
 523                                 die("unable to rename temporary pack file: %s",
 524                                     strerror(errno));
 525
 526                         /*
 527                          * Packs are runtime accessed in their mtime
 528                          * order since newer packs are more likely to contain
 529                          * younger objects.  So if we are creating multiple
 530                          * packs then we should modify the mtime of later ones
 531                          * to preserve this property.
 532                          */
 533                         if (stat(tmpname, &st) < 0) {
 534                                 warning("failed to stat %s: %s",
 535                                         tmpname, strerror(errno));
 536                         } else if (!last_mtime) {
 537                                 last_mtime = st.st_mtime;
 538                         } else {
 539                                 struct utimbuf utb;
 540                                 utb.actime = st.st_atime;
 541                                 utb.modtime = --last_mtime;
 542                                 if (utime(tmpname, &utb) < 0)
 543                                         warning("failed utime() on %s: %s",
 544                                                 tmpname, strerror(errno));
 545                         }
 546
 547                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 548                                  base_name, sha1_to_hex(sha1));
 549                         if (adjust_perm(idx_tmp_name, mode))
 550                                 die("unable to make temporary index file readable: %s",
 551                                     strerror(errno));
 552                         if (rename(idx_tmp_name, tmpname))
 553                                 die("unable to rename temporary index file: %s",
 554                                     strerror(errno));
 555
 556                         free(idx_tmp_name);
 557                         free(pack_tmp_name);
 558                         puts(sha1_to_hex(sha1));
 559                 }
 560
 561                 /* mark written objects as written to previous pack */
 562                 for (j = 0; j < nr_written; j++) {
 563                         written_list[j]->offset = (off_t)-1;
 564                 }
 565                 nr_remaining -= nr_written;
 566         } while (nr_remaining && i < nr_objects);
 567
 568         free(written_list);
 569         stop_progress(&progress_state);
 570         if (written != nr_result)
 571                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
 572                         written, nr_result);
 573         /*
 574          * We have scanned through [0 ... i).  Since we have written
 575          * the correct number of objects,  the remaining [i ... nr_objects)
 576          * items must be either already written (due to out-of-order delta base)
 577          * or a preferred base.  Count those which are neither and complain if any.
 578          */
 579         for (j = 0; i < nr_objects; i++) {
 580                 struct object_entry *e = objects + i;
 581                 j += !e->idx.offset && !e->preferred_base;
 582         }
 583         if (j)
 584                 die("wrote %"PRIu32" objects as expected but %"PRIu32
 585                         " unwritten", written, j);
 586 }
 587
 588 static int locate_object_entry_hash(const unsigned char *sha1)
 589 {
 590         int i;
 591         unsigned int ui;
 592         memcpy(&ui, sha1, sizeof(unsigned int));
 593         i = ui % object_ix_hashsz;
 594         while (0 < object_ix[i]) {
 595                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 596                         return i;
 597                 if (++i == object_ix_hashsz)
 598                         i = 0;
 599         }
 600         return -1 - i;
 601 }
 602
 603 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 604 {
 605         int i;
 606
 607         if (!object_ix_hashsz)
 608                 return NULL;
 609
 610         i = locate_object_entry_hash(sha1);
 611         if (0 <= i)
 612                 return &objects[object_ix[i]-1];
 613         return NULL;
 614 }
 615
 616 static void rehash_objects(void)
 617 {
 618         uint32_t i;
 619         struct object_entry *oe;
 620
 621         object_ix_hashsz = nr_objects * 3;
 622         if (object_ix_hashsz < 1024)
 623                 object_ix_hashsz = 1024;
 624         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 625         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 626         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 627                 int ix = locate_object_entry_hash(oe->idx.sha1);
 628                 if (0 <= ix)
 629                         continue;
 630                 ix = -1 - ix;
 631                 object_ix[ix] = i + 1;
 632         }
 633 }
 634
 635 static unsigned name_hash(const char *name)
 636 {
 637         unsigned char c;
 638         unsigned hash = 0;
 639
 640         if (!name)
 641                 return 0;
 642
 643         /*
 644          * This effectively just creates a sortable number from the
 645          * last sixteen non-whitespace characters. Last characters
 646          * count "most", so things that end in ".c" sort together.
 647          */
 648         while ((c = *name++) != 0) {
 649                 if (isspace(c))
 650                         continue;
 651                 hash = (hash >> 2) + (c << 24);
 652         }
 653         return hash;
 654 }
 655
 656 static void setup_delta_attr_check(struct git_attr_check *check)
 657 {
 658         static struct git_attr *attr_delta;
 659
 660         if (!attr_delta)
 661                 attr_delta = git_attr("delta", 5);
 662
 663         check[0].attr = attr_delta;
 664 }
 665
 666 static int no_try_delta(const char *path)
 667 {
 668         struct git_attr_check check[1];
 669
 670         setup_delta_attr_check(check);
 671         if (git_checkattr(path, ARRAY_SIZE(check), check))
 672                 return 0;
 673         if (ATTR_FALSE(check->value))
 674                 return 1;
 675         return 0;
 676 }
 677
 678 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 679                             const char *name, int exclude)
 680 {
 681         struct object_entry *entry;
 682         struct packed_git *p, *found_pack = NULL;
 683         off_t found_offset = 0;
 684         int ix;
 685         unsigned hash = name_hash(name);
 686
 687         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 688         if (ix >= 0) {
 689                 if (exclude) {
 690                         entry = objects + object_ix[ix] - 1;
 691                         if (!entry->preferred_base)
 692                                 nr_result--;
 693                         entry->preferred_base = 1;
 694                 }
 695                 return 0;
 696         }
 697
 698         for (p = packed_git; p; p = p->next) {
 699                 off_t offset = find_pack_entry_one(sha1, p);
 700                 if (offset) {
 701                         if (!found_pack) {
 702                                 found_offset = offset;
 703                                 found_pack = p;
 704                         }
 705                         if (exclude)
 706                                 break;
 707                         if (incremental)
 708                                 return 0;
 709                         if (local && !p->pack_local)
 710                                 return 0;
 711                 }
 712         }
 713
 714         if (nr_objects >= nr_alloc) {
 715                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 716                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 717         }
 718
 719         entry = objects + nr_objects++;
 720         memset(entry, 0, sizeof(*entry));
 721         hashcpy(entry->idx.sha1, sha1);
 722         entry->hash = hash;
 723         if (type)
 724                 entry->type = type;
 725         if (exclude)
 726                 entry->preferred_base = 1;
 727         else
 728                 nr_result++;
 729         if (found_pack) {
 730                 entry->in_pack = found_pack;
 731                 entry->in_pack_offset = found_offset;
 732         }
 733
 734         if (object_ix_hashsz * 3 <= nr_objects * 4)
 735                 rehash_objects();
 736         else
 737                 object_ix[-1 - ix] = nr_objects;
 738
 739         display_progress(progress_state, nr_objects);
 740
 741         if (name && no_try_delta(name))
 742                 entry->no_try_delta = 1;
 743
 744         return 1;
 745 }
 746
 747 struct pbase_tree_cache {
 748         unsigned char sha1[20];
 749         int ref;
 750         int temporary;
 751         void *tree_data;
 752         unsigned long tree_size;
 753 };
 754
 755 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 756 static int pbase_tree_cache_ix(const unsigned char *sha1)
 757 {
 758         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 759 }
 760 static int pbase_tree_cache_ix_incr(int ix)
 761 {
 762         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 763 }
 764
 765 static struct pbase_tree {
 766         struct pbase_tree *next;
 767         /* This is a phony "cache" entry; we are not
 768          * going to evict it nor find it through _get()
 769          * mechanism -- this is for the toplevel node that
 770          * would almost always change with any commit.
 771          */
 772         struct pbase_tree_cache pcache;
 773 } *pbase_tree;
 774
 775 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 776 {
 777         struct pbase_tree_cache *ent, *nent;
 778         void *data;
 779         unsigned long size;
 780         enum object_type type;
 781         int neigh;
 782         int my_ix = pbase_tree_cache_ix(sha1);
 783         int available_ix = -1;
 784
 785         /* pbase-tree-cache acts as a limited hashtable.
 786          * your object will be found at your index or within a few
 787          * slots after that slot if it is cached.
 788          */
 789         for (neigh = 0; neigh < 8; neigh++) {
 790                 ent = pbase_tree_cache[my_ix];
 791                 if (ent && !hashcmp(ent->sha1, sha1)) {
 792                         ent->ref++;
 793                         return ent;
 794                 }
 795                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 796                          ((0 <= available_ix) &&
 797                           (!ent && pbase_tree_cache[available_ix])))
 798                         available_ix = my_ix;
 799                 if (!ent)
 800                         break;
 801                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 802         }
 803
 804         /* Did not find one.  Either we got a bogus request or
 805          * we need to read and perhaps cache.
 806          */
 807         data = read_sha1_file(sha1, &type, &size);
 808         if (!data)
 809                 return NULL;
 810         if (type != OBJ_TREE) {
 811                 free(data);
 812                 return NULL;
 813         }
 814
 815         /* We need to either cache or return a throwaway copy */
 816
 817         if (available_ix < 0)
 818                 ent = NULL;
 819         else {
 820                 ent = pbase_tree_cache[available_ix];
 821                 my_ix = available_ix;
 822         }
 823
 824         if (!ent) {
 825                 nent = xmalloc(sizeof(*nent));
 826                 nent->temporary = (available_ix < 0);
 827         }
 828         else {
 829                 /* evict and reuse */
 830                 free(ent->tree_data);
 831                 nent = ent;
 832         }
 833         hashcpy(nent->sha1, sha1);
 834         nent->tree_data = data;
 835         nent->tree_size = size;
 836         nent->ref = 1;
 837         if (!nent->temporary)
 838                 pbase_tree_cache[my_ix] = nent;
 839         return nent;
 840 }
 841
 842 static void pbase_tree_put(struct pbase_tree_cache *cache)
 843 {
 844         if (!cache->temporary) {
 845                 cache->ref--;
 846                 return;
 847         }
 848         free(cache->tree_data);
 849         free(cache);
 850 }
 851
 852 static int name_cmp_len(const char *name)
 853 {
 854         int i;
 855         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 856                 ;
 857         return i;
 858 }
 859
 860 static void add_pbase_object(struct tree_desc *tree,
 861                              const char *name,
 862                              int cmplen,
 863                              const char *fullname)
 864 {
 865         struct name_entry entry;
 866         int cmp;
 867
 868         while (tree_entry(tree,&entry)) {
 869                 if (S_ISGITLINK(entry.mode))
 870                         continue;
 871                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 872                       memcmp(name, entry.path, cmplen);
 873                 if (cmp > 0)
 874                         continue;
 875                 if (cmp < 0)
 876                         return;
 877                 if (name[cmplen] != '/') {
 878                         add_object_entry(entry.sha1,
 879                                          object_type(entry.mode),
 880                                          fullname, 1);
 881                         return;
 882                 }
 883                 if (S_ISDIR(entry.mode)) {
 884                         struct tree_desc sub;
 885                         struct pbase_tree_cache *tree;
 886                         const char *down = name+cmplen+1;
 887                         int downlen = name_cmp_len(down);
 888
 889                         tree = pbase_tree_get(entry.sha1);
 890                         if (!tree)
 891                                 return;
 892                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 893
 894                         add_pbase_object(&sub, down, downlen, fullname);
 895                         pbase_tree_put(tree);
 896                 }
 897         }
 898 }
 899
 900 static unsigned *done_pbase_paths;
 901 static int done_pbase_paths_num;
 902 static int done_pbase_paths_alloc;
 903 static int done_pbase_path_pos(unsigned hash)
 904 {
 905         int lo = 0;
 906         int hi = done_pbase_paths_num;
 907         while (lo < hi) {
 908                 int mi = (hi + lo) / 2;
 909                 if (done_pbase_paths[mi] == hash)
 910                         return mi;
 911                 if (done_pbase_paths[mi] < hash)
 912                         hi = mi;
 913                 else
 914                         lo = mi + 1;
 915         }
 916         return -lo-1;
 917 }
 918
 919 static int check_pbase_path(unsigned hash)
 920 {
 921         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 922         if (0 <= pos)
 923                 return 1;
 924         pos = -pos - 1;
 925         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 926                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 927                 done_pbase_paths = xrealloc(done_pbase_paths,
 928                                             done_pbase_paths_alloc *
 929                                             sizeof(unsigned));
 930         }
 931         done_pbase_paths_num++;
 932         if (pos < done_pbase_paths_num)
 933                 memmove(done_pbase_paths + pos + 1,
 934                         done_pbase_paths + pos,
 935                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 936         done_pbase_paths[pos] = hash;
 937         return 0;
 938 }
 939
 940 static void add_preferred_base_object(const char *name)
 941 {
 942         struct pbase_tree *it;
 943         int cmplen;
 944         unsigned hash = name_hash(name);
 945
 946         if (!num_preferred_base || check_pbase_path(hash))
 947                 return;
 948
 949         cmplen = name_cmp_len(name);
 950         for (it = pbase_tree; it; it = it->next) {
 951                 if (cmplen == 0) {
 952                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 953                 }
 954                 else {
 955                         struct tree_desc tree;
 956                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 957                         add_pbase_object(&tree, name, cmplen, name);
 958                 }
 959         }
 960 }
 961
 962 static void add_preferred_base(unsigned char *sha1)
 963 {
 964         struct pbase_tree *it;
 965         void *data;
 966         unsigned long size;
 967         unsigned char tree_sha1[20];
 968
 969         if (window <= num_preferred_base++)
 970                 return;
 971
 972         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 973         if (!data)
 974                 return;
 975
 976         for (it = pbase_tree; it; it = it->next) {
 977                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 978                         free(data);
 979                         return;
 980                 }
 981         }
 982
 983         it = xcalloc(1, sizeof(*it));
 984         it->next = pbase_tree;
 985         pbase_tree = it;
 986
 987         hashcpy(it->pcache.sha1, tree_sha1);
 988         it->pcache.tree_data = data;
 989         it->pcache.tree_size = size;
 990 }
 991
 992 static void check_object(struct object_entry *entry)
 993 {
 994         if (entry->in_pack) {
 995                 struct packed_git *p = entry->in_pack;
 996                 struct pack_window *w_curs = NULL;
 997                 const unsigned char *base_ref = NULL;
 998                 struct object_entry *base_entry;
 999                 unsigned long used, used_0;
1000                 unsigned int avail;
1001                 off_t ofs;
1002                 unsigned char *buf, c;
1003
1004                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1005
1006                 /*
1007                  * We want in_pack_type even if we do not reuse delta
1008                  * since non-delta representations could still be reused.
1009                  */
1010                 used = unpack_object_header_gently(buf, avail,
1011                                                    &entry->in_pack_type,
1012                                                    &entry->size);
1013
1014                 /*
1015                  * Determine if this is a delta and if so whether we can
1016                  * reuse it or not.  Otherwise let's find out as cheaply as
1017                  * possible what the actual type and size for this object is.
1018                  */
1019                 switch (entry->in_pack_type) {
1020                 default:
1021                         /* Not a delta hence we've already got all we need. */
1022                         entry->type = entry->in_pack_type;
1023                         entry->in_pack_header_size = used;
1024                         unuse_pack(&w_curs);
1025                         return;
1026                 case OBJ_REF_DELTA:
1027                         if (reuse_delta && !entry->preferred_base)
1028                                 base_ref = use_pack(p, &w_curs,
1029                                                 entry->in_pack_offset + used, NULL);
1030                         entry->in_pack_header_size = used + 20;
1031                         break;
1032                 case OBJ_OFS_DELTA:
1033                         buf = use_pack(p, &w_curs,
1034                                        entry->in_pack_offset + used, NULL);
1035                         used_0 = 0;
1036                         c = buf[used_0++];
1037                         ofs = c & 127;
1038                         while (c & 128) {
1039                                 ofs += 1;
1040                                 if (!ofs || MSB(ofs, 7))
1041                                         die("delta base offset overflow in pack for %s",
1042                                             sha1_to_hex(entry->idx.sha1));
1043                                 c = buf[used_0++];
1044                                 ofs = (ofs << 7) + (c & 127);
1045                         }
1046                         if (ofs >= entry->in_pack_offset)
1047                                 die("delta base offset out of bound for %s",
1048                                     sha1_to_hex(entry->idx.sha1));
1049                         ofs = entry->in_pack_offset - ofs;
1050                         if (reuse_delta && !entry->preferred_base) {
1051                                 struct revindex_entry *revidx;
1052                                 revidx = find_pack_revindex(p, ofs);
1053                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1054                         }
1055                         entry->in_pack_header_size = used + used_0;
1056                         break;
1057                 }
1058
1059                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1060                         /*
1061                          * If base_ref was set above that means we wish to
1062                          * reuse delta data, and we even found that base
1063                          * in the list of objects we want to pack. Goodie!
1064                          *
1065                          * Depth value does not matter - find_deltas() will
1066                          * never consider reused delta as the base object to
1067                          * deltify other objects against, in order to avoid
1068                          * circular deltas.
1069                          */
1070                         entry->type = entry->in_pack_type;
1071                         entry->delta = base_entry;
1072                         entry->delta_sibling = base_entry->delta_child;
1073                         base_entry->delta_child = entry;
1074                         unuse_pack(&w_curs);
1075                         return;
1076                 }
1077
1078                 if (entry->type) {
1079                         /*
1080                          * This must be a delta and we already know what the
1081                          * final object type is.  Let's extract the actual
1082                          * object size from the delta header.
1083                          */
1084                         entry->size = get_size_from_delta(p, &w_curs,
1085                                         entry->in_pack_offset + entry->in_pack_header_size);
1086                         unuse_pack(&w_curs);
1087                         return;
1088                 }
1089
1090                 /*
1091                  * No choice but to fall back to the recursive delta walk
1092                  * with sha1_object_info() to find about the object type
1093                  * at this point...
1094                  */
1095                 unuse_pack(&w_curs);
1096         }
1097
1098         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1099         if (entry->type < 0)
1100                 die("unable to get type of object %s",
1101                     sha1_to_hex(entry->idx.sha1));
1102 }
1103
1104 static int pack_offset_sort(const void *_a, const void *_b)
1105 {
1106         const struct object_entry *a = *(struct object_entry **)_a;
1107         const struct object_entry *b = *(struct object_entry **)_b;
1108
1109         /* avoid filesystem trashing with loose objects */
1110         if (!a->in_pack && !b->in_pack)
1111                 return hashcmp(a->idx.sha1, b->idx.sha1);
1112
1113         if (a->in_pack < b->in_pack)
1114                 return -1;
1115         if (a->in_pack > b->in_pack)
1116                 return 1;
1117         return a->in_pack_offset < b->in_pack_offset ? -1 :
1118                         (a->in_pack_offset > b->in_pack_offset);
1119 }
1120
1121 static void get_object_details(void)
1122 {
1123         uint32_t i;
1124         struct object_entry **sorted_by_offset;
1125
1126         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1127         for (i = 0; i < nr_objects; i++)
1128                 sorted_by_offset[i] = objects + i;
1129         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1130
1131         for (i = 0; i < nr_objects; i++)
1132                 check_object(sorted_by_offset[i]);
1133
1134         free(sorted_by_offset);
1135 }
1136
1137 /*
1138  * We search for deltas in a list sorted by type, by filename hash, and then
1139  * by size, so that we see progressively smaller and smaller files.
1140  * That's because we prefer deltas to be from the bigger file
1141  * to the smaller -- deletes are potentially cheaper, but perhaps
1142  * more importantly, the bigger file is likely the more recent
1143  * one.  The deepest deltas are therefore the oldest objects which are
1144  * less susceptible to be accessed often.
1145  */
1146 static int type_size_sort(const void *_a, const void *_b)
1147 {
1148         const struct object_entry *a = *(struct object_entry **)_a;
1149         const struct object_entry *b = *(struct object_entry **)_b;
1150
1151         if (a->type > b->type)
1152                 return -1;
1153         if (a->type < b->type)
1154                 return 1;
1155         if (a->hash > b->hash)
1156                 return -1;
1157         if (a->hash < b->hash)
1158                 return 1;
1159         if (a->preferred_base > b->preferred_base)
1160                 return -1;
1161         if (a->preferred_base < b->preferred_base)
1162                 return 1;
1163         if (a->size > b->size)
1164                 return -1;
1165         if (a->size < b->size)
1166                 return 1;
1167         return a < b ? -1 : (a > b);  /* newest first */
1168 }
1169
1170 struct unpacked {
1171         struct object_entry *entry;
1172         void *data;
1173         struct delta_index *index;
1174         unsigned depth;
1175 };
1176
1177 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1178                            unsigned long delta_size)
1179 {
1180         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1181                 return 0;
1182
1183         if (delta_size < cache_max_small_delta_size)
1184                 return 1;
1185
1186         /* cache delta, if objects are large enough compared to delta size */
1187         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1188                 return 1;
1189
1190         return 0;
1191 }
1192
1193 #ifdef THREADED_DELTA_SEARCH
1194
1195 static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1196 #define read_lock()             pthread_mutex_lock(&read_mutex)
1197 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1198
1199 static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1200 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1201 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1202
1203 static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1204 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1205 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1206
1207 #else
1208
1209 #define read_lock()             (void)0
1210 #define read_unlock()           (void)0
1211 #define cache_lock()            (void)0
1212 #define cache_unlock()          (void)0
1213 #define progress_lock()         (void)0
1214 #define progress_unlock()       (void)0
1215
1216 #endif
1217
1218 static int try_delta(struct unpacked *trg, struct unpacked *src,
1219                      unsigned max_depth, unsigned long *mem_usage)
1220 {
1221         struct object_entry *trg_entry = trg->entry;
1222         struct object_entry *src_entry = src->entry;
1223         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1224         unsigned ref_depth;
1225         enum object_type type;
1226         void *delta_buf;
1227
1228         /* Don't bother doing diffs between different types */
1229         if (trg_entry->type != src_entry->type)
1230                 return -1;
1231
1232         /*
1233          * We do not bother to try a delta that we discarded
1234          * on an earlier try, but only when reusing delta data.
1235          */
1236         if (reuse_delta && trg_entry->in_pack &&
1237             trg_entry->in_pack == src_entry->in_pack &&
1238             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1239             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1240                 return 0;
1241
1242         /* Let's not bust the allowed depth. */
1243         if (src->depth >= max_depth)
1244                 return 0;
1245
1246         /* Now some size filtering heuristics. */
1247         trg_size = trg_entry->size;
1248         if (!trg_entry->delta) {
1249                 max_size = trg_size/2 - 20;
1250                 ref_depth = 1;
1251         } else {
1252                 max_size = trg_entry->delta_size;
1253                 ref_depth = trg->depth;
1254         }
1255         max_size = max_size * (max_depth - src->depth) /
1256                                                 (max_depth - ref_depth + 1);
1257         if (max_size == 0)
1258                 return 0;
1259         src_size = src_entry->size;
1260         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1261         if (sizediff >= max_size)
1262                 return 0;
1263         if (trg_size < src_size / 32)
1264                 return 0;
1265
1266         /* Load data if not already done */
1267         if (!trg->data) {
1268                 read_lock();
1269                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1270                 read_unlock();
1271                 if (!trg->data)
1272                         die("object %s cannot be read",
1273                             sha1_to_hex(trg_entry->idx.sha1));
1274                 if (sz != trg_size)
1275                         die("object %s inconsistent object length (%lu vs %lu)",
1276                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1277                 *mem_usage += sz;
1278         }
1279         if (!src->data) {
1280                 read_lock();
1281                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1282                 read_unlock();
1283                 if (!src->data)
1284                         die("object %s cannot be read",
1285                             sha1_to_hex(src_entry->idx.sha1));
1286                 if (sz != src_size)
1287                         die("object %s inconsistent object length (%lu vs %lu)",
1288                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1289                 *mem_usage += sz;
1290         }
1291         if (!src->index) {
1292                 src->index = create_delta_index(src->data, src_size);
1293                 if (!src->index) {
1294                         static int warned = 0;
1295                         if (!warned++)
1296                                 warning("suboptimal pack - out of memory");
1297                         return 0;
1298                 }
1299                 *mem_usage += sizeof_delta_index(src->index);
1300         }
1301
1302         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1303         if (!delta_buf)
1304                 return 0;
1305
1306         if (trg_entry->delta) {
1307                 /* Prefer only shallower same-sized deltas. */
1308                 if (delta_size == trg_entry->delta_size &&
1309                     src->depth + 1 >= trg->depth) {
1310                         free(delta_buf);
1311                         return 0;
1312                 }
1313         }
1314
1315         /*
1316          * Handle memory allocation outside of the cache
1317          * accounting lock.  Compiler will optimize the strangeness
1318          * away when THREADED_DELTA_SEARCH is not defined.
1319          */
1320         free(trg_entry->delta_data);
1321         cache_lock();
1322         if (trg_entry->delta_data) {
1323                 delta_cache_size -= trg_entry->delta_size;
1324                 trg_entry->delta_data = NULL;
1325         }
1326         if (delta_cacheable(src_size, trg_size, delta_size)) {
1327                 delta_cache_size += delta_size;
1328                 cache_unlock();
1329                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1330         } else {
1331                 cache_unlock();
1332                 free(delta_buf);
1333         }
1334
1335         trg_entry->delta = src_entry;
1336         trg_entry->delta_size = delta_size;
1337         trg->depth = src->depth + 1;
1338
1339         return 1;
1340 }
1341
1342 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1343 {
1344         struct object_entry *child = me->delta_child;
1345         unsigned int m = n;
1346         while (child) {
1347                 unsigned int c = check_delta_limit(child, n + 1);
1348                 if (m < c)
1349                         m = c;
1350                 child = child->delta_sibling;
1351         }
1352         return m;
1353 }
1354
1355 static unsigned long free_unpacked(struct unpacked *n)
1356 {
1357         unsigned long freed_mem = sizeof_delta_index(n->index);
1358         free_delta_index(n->index);
1359         n->index = NULL;
1360         if (n->data) {
1361                 freed_mem += n->entry->size;
1362                 free(n->data);
1363                 n->data = NULL;
1364         }
1365         n->entry = NULL;
1366         n->depth = 0;
1367         return freed_mem;
1368 }
1369
1370 static void find_deltas(struct object_entry **list, unsigned *list_size,
1371                         int window, int depth, unsigned *processed)
1372 {
1373         uint32_t i, idx = 0, count = 0;
1374         unsigned int array_size = window * sizeof(struct unpacked);
1375         struct unpacked *array;
1376         unsigned long mem_usage = 0;
1377
1378         array = xmalloc(array_size);
1379         memset(array, 0, array_size);
1380
1381         for (;;) {
1382                 struct object_entry *entry = *list++;
1383                 struct unpacked *n = array + idx;
1384                 int j, max_depth, best_base = -1;
1385
1386                 progress_lock();
1387                 if (!*list_size) {
1388                         progress_unlock();
1389                         break;
1390                 }
1391                 (*list_size)--;
1392                 if (!entry->preferred_base) {
1393                         (*processed)++;
1394                         display_progress(progress_state, *processed);
1395                 }
1396                 progress_unlock();
1397
1398                 mem_usage -= free_unpacked(n);
1399                 n->entry = entry;
1400
1401                 while (window_memory_limit &&
1402                        mem_usage > window_memory_limit &&
1403                        count > 1) {
1404                         uint32_t tail = (idx + window - count) % window;
1405                         mem_usage -= free_unpacked(array + tail);
1406                         count--;
1407                 }
1408
1409                 /* We do not compute delta to *create* objects we are not
1410                  * going to pack.
1411                  */
1412                 if (entry->preferred_base)
1413                         goto next;
1414
1415                 /*
1416                  * If the current object is at pack edge, take the depth the
1417                  * objects that depend on the current object into account
1418                  * otherwise they would become too deep.
1419                  */
1420                 max_depth = depth;
1421                 if (entry->delta_child) {
1422                         max_depth -= check_delta_limit(entry, 0);
1423                         if (max_depth <= 0)
1424                                 goto next;
1425                 }
1426
1427                 j = window;
1428                 while (--j > 0) {
1429                         int ret;
1430                         uint32_t other_idx = idx + j;
1431                         struct unpacked *m;
1432                         if (other_idx >= window)
1433                                 other_idx -= window;
1434                         m = array + other_idx;
1435                         if (!m->entry)
1436                                 break;
1437                         ret = try_delta(n, m, max_depth, &mem_usage);
1438                         if (ret < 0)
1439                                 break;
1440                         else if (ret > 0)
1441                                 best_base = other_idx;
1442                 }
1443
1444                 /*
1445                  * If we decided to cache the delta data, then it is best
1446                  * to compress it right away.  First because we have to do
1447                  * it anyway, and doing it here while we're threaded will
1448                  * save a lot of time in the non threaded write phase,
1449                  * as well as allow for caching more deltas within
1450                  * the same cache size limit.
1451                  * ...
1452                  * But only if not writing to stdout, since in that case
1453                  * the network is most likely throttling writes anyway,
1454                  * and therefore it is best to go to the write phase ASAP
1455                  * instead, as we can afford spending more time compressing
1456                  * between writes at that moment.
1457                  */
1458                 if (entry->delta_data && !pack_to_stdout) {
1459                         entry->z_delta_size = do_compress(&entry->delta_data,
1460                                                           entry->delta_size);
1461                         cache_lock();
1462                         delta_cache_size -= entry->delta_size;
1463                         delta_cache_size += entry->z_delta_size;
1464                         cache_unlock();
1465                 }
1466
1467                 /* if we made n a delta, and if n is already at max
1468                  * depth, leaving it in the window is pointless.  we
1469                  * should evict it first.
1470                  */
1471                 if (entry->delta && max_depth <= n->depth)
1472                         continue;
1473
1474                 /*
1475                  * Move the best delta base up in the window, after the
1476                  * currently deltified object, to keep it longer.  It will
1477                  * be the first base object to be attempted next.
1478                  */
1479                 if (entry->delta) {
1480                         struct unpacked swap = array[best_base];
1481                         int dist = (window + idx - best_base) % window;
1482                         int dst = best_base;
1483                         while (dist--) {
1484                                 int src = (dst + 1) % window;
1485                                 array[dst] = array[src];
1486                                 dst = src;
1487                         }
1488                         array[dst] = swap;
1489                 }
1490
1491                 next:
1492                 idx++;
1493                 if (count + 1 < window)
1494                         count++;
1495                 if (idx >= window)
1496                         idx = 0;
1497         }
1498
1499         for (i = 0; i < window; ++i) {
1500                 free_delta_index(array[i].index);
1501                 free(array[i].data);
1502         }
1503         free(array);
1504 }
1505
1506 #ifdef THREADED_DELTA_SEARCH
1507
1508 /*
1509  * The main thread waits on the condition that (at least) one of the workers
1510  * has stopped working (which is indicated in the .working member of
1511  * struct thread_params).
1512  * When a work thread has completed its work, it sets .working to 0 and
1513  * signals the main thread and waits on the condition that .data_ready
1514  * becomes 1.
1515  */
1516
1517 struct thread_params {
1518         pthread_t thread;
1519         struct object_entry **list;
1520         unsigned list_size;
1521         unsigned remaining;
1522         int window;
1523         int depth;
1524         int working;
1525         int data_ready;
1526         pthread_mutex_t mutex;
1527         pthread_cond_t cond;
1528         unsigned *processed;
1529 };
1530
1531 static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
1532
1533 static void *threaded_find_deltas(void *arg)
1534 {
1535         struct thread_params *me = arg;
1536
1537         while (me->remaining) {
1538                 find_deltas(me->list, &me->remaining,
1539                             me->window, me->depth, me->processed);
1540
1541                 progress_lock();
1542                 me->working = 0;
1543                 pthread_cond_signal(&progress_cond);
1544                 progress_unlock();
1545
1546                 /*
1547                  * We must not set ->data_ready before we wait on the
1548                  * condition because the main thread may have set it to 1
1549                  * before we get here. In order to be sure that new
1550                  * work is available if we see 1 in ->data_ready, it
1551                  * was initialized to 0 before this thread was spawned
1552                  * and we reset it to 0 right away.
1553                  */
1554                 pthread_mutex_lock(&me->mutex);
1555                 while (!me->data_ready)
1556                         pthread_cond_wait(&me->cond, &me->mutex);
1557                 me->data_ready = 0;
1558                 pthread_mutex_unlock(&me->mutex);
1559         }
1560         /* leave ->working 1 so that this doesn't get more work assigned */
1561         return NULL;
1562 }
1563
1564 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1565                            int window, int depth, unsigned *processed)
1566 {
1567         struct thread_params p[delta_search_threads];
1568         int i, ret, active_threads = 0;
1569
1570         if (delta_search_threads <= 1) {
1571                 find_deltas(list, &list_size, window, depth, processed);
1572                 return;
1573         }
1574
1575         /* Partition the work amongst work threads. */
1576         for (i = 0; i < delta_search_threads; i++) {
1577                 unsigned sub_size = list_size / (delta_search_threads - i);
1578
1579                 p[i].window = window;
1580                 p[i].depth = depth;
1581                 p[i].processed = processed;
1582                 p[i].working = 1;
1583                 p[i].data_ready = 0;
1584
1585                 /* try to split chunks on "path" boundaries */
1586                 while (sub_size && sub_size < list_size &&
1587                        list[sub_size]->hash &&
1588                        list[sub_size]->hash == list[sub_size-1]->hash)
1589                         sub_size++;
1590
1591                 p[i].list = list;
1592                 p[i].list_size = sub_size;
1593                 p[i].remaining = sub_size;
1594
1595                 list += sub_size;
1596                 list_size -= sub_size;
1597         }
1598
1599         /* Start work threads. */
1600         for (i = 0; i < delta_search_threads; i++) {
1601                 if (!p[i].list_size)
1602                         continue;
1603                 pthread_mutex_init(&p[i].mutex, NULL);
1604                 pthread_cond_init(&p[i].cond, NULL);
1605                 ret = pthread_create(&p[i].thread, NULL,
1606                                      threaded_find_deltas, &p[i]);
1607                 if (ret)
1608                         die("unable to create thread: %s", strerror(ret));
1609                 active_threads++;
1610         }
1611
1612         /*
1613          * Now let's wait for work completion.  Each time a thread is done
1614          * with its work, we steal half of the remaining work from the
1615          * thread with the largest number of unprocessed objects and give
1616          * it to that newly idle thread.  This ensure good load balancing
1617          * until the remaining object list segments are simply too short
1618          * to be worth splitting anymore.
1619          */
1620         while (active_threads) {
1621                 struct thread_params *target = NULL;
1622                 struct thread_params *victim = NULL;
1623                 unsigned sub_size = 0;
1624
1625                 progress_lock();
1626                 for (;;) {
1627                         for (i = 0; !target && i < delta_search_threads; i++)
1628                                 if (!p[i].working)
1629                                         target = &p[i];
1630                         if (target)
1631                                 break;
1632                         pthread_cond_wait(&progress_cond, &progress_mutex);
1633                 }
1634
1635                 for (i = 0; i < delta_search_threads; i++)
1636                         if (p[i].remaining > 2*window &&
1637                             (!victim || victim->remaining < p[i].remaining))
1638                                 victim = &p[i];
1639                 if (victim) {
1640                         sub_size = victim->remaining / 2;
1641                         list = victim->list + victim->list_size - sub_size;
1642                         while (sub_size && list[0]->hash &&
1643                                list[0]->hash == list[-1]->hash) {
1644                                 list++;
1645                                 sub_size--;
1646                         }
1647                         if (!sub_size) {
1648                                 /*
1649                                  * It is possible for some "paths" to have
1650                                  * so many objects that no hash boundary
1651                                  * might be found.  Let's just steal the
1652                                  * exact half in that case.
1653                                  */
1654                                 sub_size = victim->remaining / 2;
1655                                 list -= sub_size;
1656                         }
1657                         target->list = list;
1658                         victim->list_size -= sub_size;
1659                         victim->remaining -= sub_size;
1660                 }
1661                 target->list_size = sub_size;
1662                 target->remaining = sub_size;
1663                 target->working = 1;
1664                 progress_unlock();
1665
1666                 pthread_mutex_lock(&target->mutex);
1667                 target->data_ready = 1;
1668                 pthread_cond_signal(&target->cond);
1669                 pthread_mutex_unlock(&target->mutex);
1670
1671                 if (!sub_size) {
1672                         pthread_join(target->thread, NULL);
1673                         pthread_cond_destroy(&target->cond);
1674                         pthread_mutex_destroy(&target->mutex);
1675                         active_threads--;
1676                 }
1677         }
1678 }
1679
1680 #else
1681 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1682 #endif
1683
1684 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1685 {
1686         unsigned char peeled[20];
1687
1688         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1689             !peel_ref(path, peeled)        && /* peelable? */
1690             !is_null_sha1(peeled)          && /* annotated tag? */
1691             locate_object_entry(peeled))      /* object packed? */
1692                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1693         return 0;
1694 }
1695
1696 static void prepare_pack(int window, int depth)
1697 {
1698         struct object_entry **delta_list;
1699         uint32_t i, nr_deltas;
1700         unsigned n;
1701
1702         get_object_details();
1703
1704         if (!nr_objects || !window || !depth)
1705                 return;
1706
1707         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1708         nr_deltas = n = 0;
1709
1710         for (i = 0; i < nr_objects; i++) {
1711                 struct object_entry *entry = objects + i;
1712
1713                 if (entry->delta)
1714                         /* This happens if we decided to reuse existing
1715                          * delta from a pack.  "reuse_delta &&" is implied.
1716                          */
1717                         continue;
1718
1719                 if (entry->size < 50)
1720                         continue;
1721
1722                 if (entry->no_try_delta)
1723                         continue;
1724
1725                 if (!entry->preferred_base)
1726                         nr_deltas++;
1727
1728                 delta_list[n++] = entry;
1729         }
1730
1731         if (nr_deltas && n > 1) {
1732                 unsigned nr_done = 0;
1733                 if (progress)
1734                         progress_state = start_progress("Compressing objects",
1735                                                         nr_deltas);
1736                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1737                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1738                 stop_progress(&progress_state);
1739                 if (nr_done != nr_deltas)
1740                         die("inconsistency with delta count");
1741         }
1742         free(delta_list);
1743 }
1744
1745 static int git_pack_config(const char *k, const char *v, void *cb)
1746 {
1747         if(!strcmp(k, "pack.window")) {
1748                 window = git_config_int(k, v);
1749                 return 0;
1750         }
1751         if (!strcmp(k, "pack.windowmemory")) {
1752                 window_memory_limit = git_config_ulong(k, v);
1753                 return 0;
1754         }
1755         if (!strcmp(k, "pack.depth")) {
1756                 depth = git_config_int(k, v);
1757                 return 0;
1758         }
1759         if (!strcmp(k, "pack.compression")) {
1760                 int level = git_config_int(k, v);
1761                 if (level == -1)
1762                         level = Z_DEFAULT_COMPRESSION;
1763                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1764                         die("bad pack compression level %d", level);
1765                 pack_compression_level = level;
1766                 pack_compression_seen = 1;
1767                 return 0;
1768         }
1769         if (!strcmp(k, "pack.deltacachesize")) {
1770                 max_delta_cache_size = git_config_int(k, v);
1771                 return 0;
1772         }
1773         if (!strcmp(k, "pack.deltacachelimit")) {
1774                 cache_max_small_delta_size = git_config_int(k, v);
1775                 return 0;
1776         }
1777         if (!strcmp(k, "pack.threads")) {
1778                 delta_search_threads = git_config_int(k, v);
1779                 if (delta_search_threads < 0)
1780                         die("invalid number of threads specified (%d)",
1781                             delta_search_threads);
1782 #ifndef THREADED_DELTA_SEARCH
1783                 if (delta_search_threads != 1)
1784                         warning("no threads support, ignoring %s", k);
1785 #endif
1786                 return 0;
1787         }
1788         if (!strcmp(k, "pack.indexversion")) {
1789                 pack_idx_default_version = git_config_int(k, v);
1790                 if (pack_idx_default_version > 2)
1791                         die("bad pack.indexversion=%"PRIu32,
1792                                 pack_idx_default_version);
1793                 return 0;
1794         }
1795         if (!strcmp(k, "pack.packsizelimit")) {
1796                 pack_size_limit_cfg = git_config_ulong(k, v);
1797                 return 0;
1798         }
1799         return git_default_config(k, v, cb);
1800 }
1801
1802 static void read_object_list_from_stdin(void)
1803 {
1804         char line[40 + 1 + PATH_MAX + 2];
1805         unsigned char sha1[20];
1806
1807         for (;;) {
1808                 if (!fgets(line, sizeof(line), stdin)) {
1809                         if (feof(stdin))
1810                                 break;
1811                         if (!ferror(stdin))
1812                                 die("fgets returned NULL, not EOF, not error!");
1813                         if (errno != EINTR)
1814                                 die("fgets: %s", strerror(errno));
1815                         clearerr(stdin);
1816                         continue;
1817                 }
1818                 if (line[0] == '-') {
1819                         if (get_sha1_hex(line+1, sha1))
1820                                 die("expected edge sha1, got garbage:\n %s",
1821                                     line);
1822                         add_preferred_base(sha1);
1823                         continue;
1824                 }
1825                 if (get_sha1_hex(line, sha1))
1826                         die("expected sha1, got garbage:\n %s", line);
1827
1828                 add_preferred_base_object(line+41);
1829                 add_object_entry(sha1, 0, line+41, 0);
1830         }
1831 }
1832
1833 #define OBJECT_ADDED (1u<<20)
1834
1835 static void show_commit(struct commit *commit)
1836 {
1837         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1838         commit->object.flags |= OBJECT_ADDED;
1839 }
1840
1841 static void show_object(struct object_array_entry *p)
1842 {
1843         add_preferred_base_object(p->name);
1844         add_object_entry(p->item->sha1, p->item->type, p->name, 0);
1845         p->item->flags |= OBJECT_ADDED;
1846 }
1847
1848 static void show_edge(struct commit *commit)
1849 {
1850         add_preferred_base(commit->object.sha1);
1851 }
1852
1853 struct in_pack_object {
1854         off_t offset;
1855         struct object *object;
1856 };
1857
1858 struct in_pack {
1859         int alloc;
1860         int nr;
1861         struct in_pack_object *array;
1862 };
1863
1864 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1865 {
1866         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1867         in_pack->array[in_pack->nr].object = object;
1868         in_pack->nr++;
1869 }
1870
1871 /*
1872  * Compare the objects in the offset order, in order to emulate the
1873  * "git-rev-list --objects" output that produced the pack originally.
1874  */
1875 static int ofscmp(const void *a_, const void *b_)
1876 {
1877         struct in_pack_object *a = (struct in_pack_object *)a_;
1878         struct in_pack_object *b = (struct in_pack_object *)b_;
1879
1880         if (a->offset < b->offset)
1881                 return -1;
1882         else if (a->offset > b->offset)
1883                 return 1;
1884         else
1885                 return hashcmp(a->object->sha1, b->object->sha1);
1886 }
1887
1888 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1889 {
1890         struct packed_git *p;
1891         struct in_pack in_pack;
1892         uint32_t i;
1893
1894         memset(&in_pack, 0, sizeof(in_pack));
1895
1896         for (p = packed_git; p; p = p->next) {
1897                 const unsigned char *sha1;
1898                 struct object *o;
1899
1900                 for (i = 0; i < revs->num_ignore_packed; i++) {
1901                         if (matches_pack_name(p, revs->ignore_packed[i]))
1902                                 break;
1903                 }
1904                 if (revs->num_ignore_packed <= i)
1905                         continue;
1906                 if (open_pack_index(p))
1907                         die("cannot open pack index");
1908
1909                 ALLOC_GROW(in_pack.array,
1910                            in_pack.nr + p->num_objects,
1911                            in_pack.alloc);
1912
1913                 for (i = 0; i < p->num_objects; i++) {
1914                         sha1 = nth_packed_object_sha1(p, i);
1915                         o = lookup_unknown_object(sha1);
1916                         if (!(o->flags & OBJECT_ADDED))
1917                                 mark_in_pack_object(o, p, &in_pack);
1918                         o->flags |= OBJECT_ADDED;
1919                 }
1920         }
1921
1922         if (in_pack.nr) {
1923                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
1924                       ofscmp);
1925                 for (i = 0; i < in_pack.nr; i++) {
1926                         struct object *o = in_pack.array[i].object;
1927                         add_object_entry(o->sha1, o->type, "", 0);
1928                 }
1929         }
1930         free(in_pack.array);
1931 }
1932
1933 static void loosen_unused_packed_objects(struct rev_info *revs)
1934 {
1935         struct packed_git *p;
1936         uint32_t i;
1937         const unsigned char *sha1;
1938
1939         for (p = packed_git; p; p = p->next) {
1940                 for (i = 0; i < revs->num_ignore_packed; i++) {
1941                         if (matches_pack_name(p, revs->ignore_packed[i]))
1942                                 break;
1943                 }
1944                 if (revs->num_ignore_packed <= i)
1945                         continue;
1946
1947                 if (open_pack_index(p))
1948                         die("cannot open pack index");
1949
1950                 for (i = 0; i < p->num_objects; i++) {
1951                         sha1 = nth_packed_object_sha1(p, i);
1952                         if (!locate_object_entry(sha1))
1953                                 if (force_object_loose(sha1, p->mtime))
1954                                         die("unable to force loose object");
1955                 }
1956         }
1957 }
1958
1959 static void get_object_list(int ac, const char **av)
1960 {
1961         struct rev_info revs;
1962         char line[1000];
1963         int flags = 0;
1964
1965         init_revisions(&revs, NULL);
1966         save_commit_buffer = 0;
1967         setup_revisions(ac, av, &revs, NULL);
1968
1969         while (fgets(line, sizeof(line), stdin) != NULL) {
1970                 int len = strlen(line);
1971                 if (len && line[len - 1] == '\n')
1972                         line[--len] = 0;
1973                 if (!len)
1974                         break;
1975                 if (*line == '-') {
1976                         if (!strcmp(line, "--not")) {
1977                                 flags ^= UNINTERESTING;
1978                                 continue;
1979                         }
1980                         die("not a rev '%s'", line);
1981                 }
1982                 if (handle_revision_arg(line, &revs, flags, 1))
1983                         die("bad revision '%s'", line);
1984         }
1985
1986         if (prepare_revision_walk(&revs))
1987                 die("revision walk setup failed");
1988         mark_edges_uninteresting(revs.commits, &revs, show_edge);
1989         traverse_commit_list(&revs, show_commit, show_object);
1990
1991         if (keep_unreachable)
1992                 add_objects_in_unpacked_packs(&revs);
1993         if (unpack_unreachable)
1994                 loosen_unused_packed_objects(&revs);
1995 }
1996
1997 static int adjust_perm(const char *path, mode_t mode)
1998 {
1999         if (chmod(path, mode))
2000                 return -1;
2001         return adjust_shared_perm(path);
2002 }
2003
2004 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2005 {
2006         int use_internal_rev_list = 0;
2007         int thin = 0;
2008         uint32_t i;
2009         const char **rp_av;
2010         int rp_ac_alloc = 64;
2011         int rp_ac;
2012
2013         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2014
2015         rp_av[0] = "pack-objects";
2016         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2017         rp_ac = 2;
2018
2019         git_config(git_pack_config, NULL);
2020         if (!pack_compression_seen && core_compression_seen)
2021                 pack_compression_level = core_compression_level;
2022
2023         progress = isatty(2);
2024         for (i = 1; i < argc; i++) {
2025                 const char *arg = argv[i];
2026
2027                 if (*arg != '-')
2028                         break;
2029
2030                 if (!strcmp("--non-empty", arg)) {
2031                         non_empty = 1;
2032                         continue;
2033                 }
2034                 if (!strcmp("--local", arg)) {
2035                         local = 1;
2036                         continue;
2037                 }
2038                 if (!strcmp("--incremental", arg)) {
2039                         incremental = 1;
2040                         continue;
2041                 }
2042                 if (!prefixcmp(arg, "--compression=")) {
2043                         char *end;
2044                         int level = strtoul(arg+14, &end, 0);
2045                         if (!arg[14] || *end)
2046                                 usage(pack_usage);
2047                         if (level == -1)
2048                                 level = Z_DEFAULT_COMPRESSION;
2049                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2050                                 die("bad pack compression level %d", level);
2051                         pack_compression_level = level;
2052                         continue;
2053                 }
2054                 if (!prefixcmp(arg, "--max-pack-size=")) {
2055                         char *end;
2056                         pack_size_limit_cfg = 0;
2057                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2058                         if (!arg[16] || *end)
2059                                 usage(pack_usage);
2060                         continue;
2061                 }
2062                 if (!prefixcmp(arg, "--window=")) {
2063                         char *end;
2064                         window = strtoul(arg+9, &end, 0);
2065                         if (!arg[9] || *end)
2066                                 usage(pack_usage);
2067                         continue;
2068                 }
2069                 if (!prefixcmp(arg, "--window-memory=")) {
2070                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2071                                 usage(pack_usage);
2072                         continue;
2073                 }
2074                 if (!prefixcmp(arg, "--threads=")) {
2075                         char *end;
2076                         delta_search_threads = strtoul(arg+10, &end, 0);
2077                         if (!arg[10] || *end || delta_search_threads < 0)
2078                                 usage(pack_usage);
2079 #ifndef THREADED_DELTA_SEARCH
2080                         if (delta_search_threads != 1)
2081                                 warning("no threads support, "
2082                                         "ignoring %s", arg);
2083 #endif
2084                         continue;
2085                 }
2086                 if (!prefixcmp(arg, "--depth=")) {
2087                         char *end;
2088                         depth = strtoul(arg+8, &end, 0);
2089                         if (!arg[8] || *end)
2090                                 usage(pack_usage);
2091                         continue;
2092                 }
2093                 if (!strcmp("--progress", arg)) {
2094                         progress = 1;
2095                         continue;
2096                 }
2097                 if (!strcmp("--all-progress", arg)) {
2098                         progress = 2;
2099                         continue;
2100                 }
2101                 if (!strcmp("-q", arg)) {
2102                         progress = 0;
2103                         continue;
2104                 }
2105                 if (!strcmp("--no-reuse-delta", arg)) {
2106                         reuse_delta = 0;
2107                         continue;
2108                 }
2109                 if (!strcmp("--no-reuse-object", arg)) {
2110                         reuse_object = reuse_delta = 0;
2111                         continue;
2112                 }
2113                 if (!strcmp("--delta-base-offset", arg)) {
2114                         allow_ofs_delta = 1;
2115                         continue;
2116                 }
2117                 if (!strcmp("--stdout", arg)) {
2118                         pack_to_stdout = 1;
2119                         continue;
2120                 }
2121                 if (!strcmp("--revs", arg)) {
2122                         use_internal_rev_list = 1;
2123                         continue;
2124                 }
2125                 if (!strcmp("--keep-unreachable", arg)) {
2126                         keep_unreachable = 1;
2127                         continue;
2128                 }
2129                 if (!strcmp("--unpack-unreachable", arg)) {
2130                         unpack_unreachable = 1;
2131                         continue;
2132                 }
2133                 if (!strcmp("--include-tag", arg)) {
2134                         include_tag = 1;
2135                         continue;
2136                 }
2137                 if (!strcmp("--unpacked", arg) ||
2138                     !prefixcmp(arg, "--unpacked=") ||
2139                     !strcmp("--reflog", arg) ||
2140                     !strcmp("--all", arg)) {
2141                         use_internal_rev_list = 1;
2142                         if (rp_ac >= rp_ac_alloc - 1) {
2143                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2144                                 rp_av = xrealloc(rp_av,
2145                                                  rp_ac_alloc * sizeof(*rp_av));
2146                         }
2147                         rp_av[rp_ac++] = arg;
2148                         continue;
2149                 }
2150                 if (!strcmp("--thin", arg)) {
2151                         use_internal_rev_list = 1;
2152                         thin = 1;
2153                         rp_av[1] = "--objects-edge";
2154                         continue;
2155                 }
2156                 if (!prefixcmp(arg, "--index-version=")) {
2157                         char *c;
2158                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2159                         if (pack_idx_default_version > 2)
2160                                 die("bad %s", arg);
2161                         if (*c == ',')
2162                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2163                         if (*c || pack_idx_off32_limit & 0x80000000)
2164                                 die("bad %s", arg);
2165                         continue;
2166                 }
2167                 usage(pack_usage);
2168         }
2169
2170         /* Traditionally "pack-objects [options] base extra" failed;
2171          * we would however want to take refs parameter that would
2172          * have been given to upstream rev-list ourselves, which means
2173          * we somehow want to say what the base name is.  So the
2174          * syntax would be:
2175          *
2176          * pack-objects [options] base <refs...>
2177          *
2178          * in other words, we would treat the first non-option as the
2179          * base_name and send everything else to the internal revision
2180          * walker.
2181          */
2182
2183         if (!pack_to_stdout)
2184                 base_name = argv[i++];
2185
2186         if (pack_to_stdout != !base_name)
2187                 usage(pack_usage);
2188
2189         if (!pack_to_stdout && !pack_size_limit)
2190                 pack_size_limit = pack_size_limit_cfg;
2191
2192         if (pack_to_stdout && pack_size_limit)
2193                 die("--max-pack-size cannot be used to build a pack for transfer.");
2194
2195         if (!pack_to_stdout && thin)
2196                 die("--thin cannot be used to build an indexable pack.");
2197
2198         if (keep_unreachable && unpack_unreachable)
2199                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2200
2201 #ifdef THREADED_DELTA_SEARCH
2202         if (!delta_search_threads)      /* --threads=0 means autodetect */
2203                 delta_search_threads = online_cpus();
2204 #endif
2205
2206         prepare_packed_git();
2207
2208         if (progress)
2209                 progress_state = start_progress("Counting objects", 0);
2210         if (!use_internal_rev_list)
2211                 read_object_list_from_stdin();
2212         else {
2213                 rp_av[rp_ac] = NULL;
2214                 get_object_list(rp_ac, rp_av);
2215         }
2216         if (include_tag && nr_result)
2217                 for_each_ref(add_ref_tag, NULL);
2218         stop_progress(&progress_state);
2219
2220         if (non_empty && !nr_result)
2221                 return 0;
2222         if (nr_result)
2223                 prepare_pack(window, depth);
2224         write_pack_file();
2225         if (progress)
2226                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2227                         " reused %"PRIu32" (delta %"PRIu32")\n",
2228                         written, written_delta, reused, reused_delta);
2229         return 0;
2230 }