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