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 "csum-file.h"
  12 #include "tree-walk.h"
  13 #include "diff.h"
  14 #include "revision.h"
  15 #include "list-objects.h"
  16 #include "progress.h"
  17
  18 #ifdef THREADED_DELTA_SEARCH
  19 #include <pthread.h>
  20 #endif
  21
  22 static const char pack_usage[] = "\
  23 git-pack-objects [{ -q | --progress | --all-progress }] \n\
  24         [--max-pack-size=N] [--local] [--incremental] \n\
  25         [--window=N] [--window-memory=N] [--depth=N] \n\
  26         [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
  27         [--threads=N] [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
  28         [--stdout | base-name] [--keep-unreachable] [<ref-list | <object-list]";
  29
  30 struct object_entry {
  31         struct pack_idx_entry idx;
  32         unsigned long size;     /* uncompressed size */
  33         struct packed_git *in_pack;     /* already in pack */
  34         off_t in_pack_offset;
  35         struct object_entry *delta;     /* delta base object */
  36         struct object_entry *delta_child; /* deltified objects who bases me */
  37         struct object_entry *delta_sibling; /* other deltified objects who
  38                                              * uses the same base as me
  39                                              */
  40         void *delta_data;       /* cached delta (uncompressed) */
  41         unsigned long delta_size;       /* delta data size (uncompressed) */
  42         unsigned int hash;      /* name hint hash */
  43         enum object_type type;
  44         enum object_type in_pack_type;  /* could be delta */
  45         unsigned char in_pack_header_size;
  46         unsigned char preferred_base; /* we do not pack this, but is available
  47                                        * to be used as the base object to delta
  48                                        * objects against.
  49                                        */
  50         unsigned char no_try_delta;
  51 };
  52
  53 /*
  54  * Objects we are going to pack are collected in objects array (dynamically
  55  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  56  * in the order we see -- typically rev-list --objects order that gives us
  57  * nice "minimum seek" order.
  58  */
  59 static struct object_entry *objects;
  60 static struct object_entry **written_list;
  61 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
  62
  63 static int non_empty;
  64 static int no_reuse_delta, no_reuse_object, keep_unreachable;
  65 static int local;
  66 static int incremental;
  67 static int allow_ofs_delta;
  68 static const char *base_name;
  69 static int progress = 1;
  70 static int window = 10;
  71 static uint32_t pack_size_limit;
  72 static int depth = 50;
  73 static int delta_search_threads = 1;
  74 static int pack_to_stdout;
  75 static int num_preferred_base;
  76 static struct progress progress_state;
  77 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  78 static int pack_compression_seen;
  79
  80 static unsigned long delta_cache_size = 0;
  81 static unsigned long max_delta_cache_size = 0;
  82 static unsigned long cache_max_small_delta_size = 1000;
  83
  84 static unsigned long window_memory_limit = 0;
  85
  86 /*
  87  * The object names in objects array are hashed with this hashtable,
  88  * to help looking up the entry by object name.
  89  * This hashtable is built after all the objects are seen.
  90  */
  91 static int *object_ix;
  92 static int object_ix_hashsz;
  93
  94 /*
  95  * Pack index for existing packs give us easy access to the offsets into
  96  * corresponding pack file where each object's data starts, but the entries
  97  * do not store the size of the compressed representation (uncompressed
  98  * size is easily available by examining the pack entry header).  It is
  99  * also rather expensive to find the sha1 for an object given its offset.
 100  *
 101  * We build a hashtable of existing packs (pack_revindex), and keep reverse
 102  * index here -- pack index file is sorted by object name mapping to offset;
 103  * this pack_revindex[].revindex array is a list of offset/index_nr pairs
 104  * ordered by offset, so if you know the offset of an object, next offset
 105  * is where its packed representation ends and the index_nr can be used to
 106  * get the object sha1 from the main index.
 107  */
 108 struct revindex_entry {
 109         off_t offset;
 110         unsigned int nr;
 111 };
 112 struct pack_revindex {
 113         struct packed_git *p;
 114         struct revindex_entry *revindex;
 115 };
 116 static struct  pack_revindex *pack_revindex;
 117 static int pack_revindex_hashsz;
 118
 119 /*
 120  * stats
 121  */
 122 static uint32_t written, written_delta;
 123 static uint32_t reused, reused_delta;
 124
 125 static int pack_revindex_ix(struct packed_git *p)
 126 {
 127         unsigned long ui = (unsigned long)p;
 128         int i;
 129
 130         ui = ui ^ (ui >> 16); /* defeat structure alignment */
 131         i = (int)(ui % pack_revindex_hashsz);
 132         while (pack_revindex[i].p) {
 133                 if (pack_revindex[i].p == p)
 134                         return i;
 135                 if (++i == pack_revindex_hashsz)
 136                         i = 0;
 137         }
 138         return -1 - i;
 139 }
 140
 141 static void prepare_pack_ix(void)
 142 {
 143         int num;
 144         struct packed_git *p;
 145         for (num = 0, p = packed_git; p; p = p->next)
 146                 num++;
 147         if (!num)
 148                 return;
 149         pack_revindex_hashsz = num * 11;
 150         pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
 151         for (p = packed_git; p; p = p->next) {
 152                 num = pack_revindex_ix(p);
 153                 num = - 1 - num;
 154                 pack_revindex[num].p = p;
 155         }
 156         /* revindex elements are lazily initialized */
 157 }
 158
 159 static int cmp_offset(const void *a_, const void *b_)
 160 {
 161         const struct revindex_entry *a = a_;
 162         const struct revindex_entry *b = b_;
 163         return (a->offset < b->offset) ? -1 : (a->offset > b->offset) ? 1 : 0;
 164 }
 165
 166 /*
 167  * Ordered list of offsets of objects in the pack.
 168  */
 169 static void prepare_pack_revindex(struct pack_revindex *rix)
 170 {
 171         struct packed_git *p = rix->p;
 172         int num_ent = p->num_objects;
 173         int i;
 174         const char *index = p->index_data;
 175
 176         rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1));
 177         index += 4 * 256;
 178
 179         if (p->index_version > 1) {
 180                 const uint32_t *off_32 =
 181                         (uint32_t *)(index + 8 + p->num_objects * (20 + 4));
 182                 const uint32_t *off_64 = off_32 + p->num_objects;
 183                 for (i = 0; i < num_ent; i++) {
 184                         uint32_t off = ntohl(*off_32++);
 185                         if (!(off & 0x80000000)) {
 186                                 rix->revindex[i].offset = off;
 187                         } else {
 188                                 rix->revindex[i].offset =
 189                                         ((uint64_t)ntohl(*off_64++)) << 32;
 190                                 rix->revindex[i].offset |=
 191                                         ntohl(*off_64++);
 192                         }
 193                         rix->revindex[i].nr = i;
 194                 }
 195         } else {
 196                 for (i = 0; i < num_ent; i++) {
 197                         uint32_t hl = *((uint32_t *)(index + 24 * i));
 198                         rix->revindex[i].offset = ntohl(hl);
 199                         rix->revindex[i].nr = i;
 200                 }
 201         }
 202
 203         /* This knows the pack format -- the 20-byte trailer
 204          * follows immediately after the last object data.
 205          */
 206         rix->revindex[num_ent].offset = p->pack_size - 20;
 207         rix->revindex[num_ent].nr = -1;
 208         qsort(rix->revindex, num_ent, sizeof(*rix->revindex), cmp_offset);
 209 }
 210
 211 static struct revindex_entry * find_packed_object(struct packed_git *p,
 212                                                   off_t ofs)
 213 {
 214         int num;
 215         int lo, hi;
 216         struct pack_revindex *rix;
 217         struct revindex_entry *revindex;
 218         num = pack_revindex_ix(p);
 219         if (num < 0)
 220                 die("internal error: pack revindex uninitialized");
 221         rix = &pack_revindex[num];
 222         if (!rix->revindex)
 223                 prepare_pack_revindex(rix);
 224         revindex = rix->revindex;
 225         lo = 0;
 226         hi = p->num_objects + 1;
 227         do {
 228                 int mi = (lo + hi) / 2;
 229                 if (revindex[mi].offset == ofs) {
 230                         return revindex + mi;
 231                 }
 232                 else if (ofs < revindex[mi].offset)
 233                         hi = mi;
 234                 else
 235                         lo = mi + 1;
 236         } while (lo < hi);
 237         die("internal error: pack revindex corrupt");
 238 }
 239
 240 static const unsigned char *find_packed_object_name(struct packed_git *p,
 241                                                     off_t ofs)
 242 {
 243         struct revindex_entry *entry = find_packed_object(p, ofs);
 244         return nth_packed_object_sha1(p, entry->nr);
 245 }
 246
 247 static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
 248 {
 249         unsigned long othersize, delta_size;
 250         enum object_type type;
 251         void *otherbuf = read_sha1_file(entry->delta->idx.sha1, &type, &othersize);
 252         void *delta_buf;
 253
 254         if (!otherbuf)
 255                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 256         delta_buf = diff_delta(otherbuf, othersize,
 257                                buf, size, &delta_size, 0);
 258         if (!delta_buf || delta_size != entry->delta_size)
 259                 die("delta size changed");
 260         free(buf);
 261         free(otherbuf);
 262         return delta_buf;
 263 }
 264
 265 /*
 266  * The per-object header is a pretty dense thing, which is
 267  *  - first byte: low four bits are "size", then three bits of "type",
 268  *    and the high bit is "size continues".
 269  *  - each byte afterwards: low seven bits are size continuation,
 270  *    with the high bit being "size continues"
 271  */
 272 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 273 {
 274         int n = 1;
 275         unsigned char c;
 276
 277         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 278                 die("bad type %d", type);
 279
 280         c = (type << 4) | (size & 15);
 281         size >>= 4;
 282         while (size) {
 283                 *hdr++ = c | 0x80;
 284                 c = size & 0x7f;
 285                 size >>= 7;
 286                 n++;
 287         }
 288         *hdr = c;
 289         return n;
 290 }
 291
 292 /*
 293  * we are going to reuse the existing object data as is.  make
 294  * sure it is not corrupt.
 295  */
 296 static int check_pack_inflate(struct packed_git *p,
 297                 struct pack_window **w_curs,
 298                 off_t offset,
 299                 off_t len,
 300                 unsigned long expect)
 301 {
 302         z_stream stream;
 303         unsigned char fakebuf[4096], *in;
 304         int st;
 305
 306         memset(&stream, 0, sizeof(stream));
 307         inflateInit(&stream);
 308         do {
 309                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 310                 stream.next_in = in;
 311                 stream.next_out = fakebuf;
 312                 stream.avail_out = sizeof(fakebuf);
 313                 st = inflate(&stream, Z_FINISH);
 314                 offset += stream.next_in - in;
 315         } while (st == Z_OK || st == Z_BUF_ERROR);
 316         inflateEnd(&stream);
 317         return (st == Z_STREAM_END &&
 318                 stream.total_out == expect &&
 319                 stream.total_in == len) ? 0 : -1;
 320 }
 321
 322 static int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
 323                           off_t offset, off_t len, unsigned int nr)
 324 {
 325         const uint32_t *index_crc;
 326         uint32_t data_crc = crc32(0, Z_NULL, 0);
 327
 328         do {
 329                 unsigned int avail;
 330                 void *data = use_pack(p, w_curs, offset, &avail);
 331                 if (avail > len)
 332                         avail = len;
 333                 data_crc = crc32(data_crc, data, avail);
 334                 offset += avail;
 335                 len -= avail;
 336         } while (len);
 337
 338         index_crc = p->index_data;
 339         index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
 340
 341         return data_crc != ntohl(*index_crc);
 342 }
 343
 344 static void copy_pack_data(struct sha1file *f,
 345                 struct packed_git *p,
 346                 struct pack_window **w_curs,
 347                 off_t offset,
 348                 off_t len)
 349 {
 350         unsigned char *in;
 351         unsigned int avail;
 352
 353         while (len) {
 354                 in = use_pack(p, w_curs, offset, &avail);
 355                 if (avail > len)
 356                         avail = (unsigned int)len;
 357                 sha1write(f, in, avail);
 358                 offset += avail;
 359                 len -= avail;
 360         }
 361 }
 362
 363 static unsigned long write_object(struct sha1file *f,
 364                                   struct object_entry *entry,
 365                                   off_t write_offset)
 366 {
 367         unsigned long size;
 368         enum object_type type;
 369         void *buf;
 370         unsigned char header[10];
 371         unsigned char dheader[10];
 372         unsigned hdrlen;
 373         off_t datalen;
 374         enum object_type obj_type;
 375         int to_reuse = 0;
 376         /* write limit if limited packsize and not first object */
 377         unsigned long limit = pack_size_limit && nr_written ?
 378                                 pack_size_limit - write_offset : 0;
 379                                 /* no if no delta */
 380         int usable_delta =      !entry->delta ? 0 :
 381                                 /* yes if unlimited packfile */
 382                                 !pack_size_limit ? 1 :
 383                                 /* no if base written to previous pack */
 384                                 entry->delta->idx.offset == (off_t)-1 ? 0 :
 385                                 /* otherwise double-check written to this
 386                                  * pack,  like we do below
 387                                  */
 388                                 entry->delta->idx.offset ? 1 : 0;
 389
 390         if (!pack_to_stdout)
 391                 crc32_begin(f);
 392
 393         obj_type = entry->type;
 394         if (no_reuse_object)
 395                 to_reuse = 0;   /* explicit */
 396         else if (!entry->in_pack)
 397                 to_reuse = 0;   /* can't reuse what we don't have */
 398         else if (obj_type == OBJ_REF_DELTA || obj_type == OBJ_OFS_DELTA)
 399                                 /* check_object() decided it for us ... */
 400                 to_reuse = usable_delta;
 401                                 /* ... but pack split may override that */
 402         else if (obj_type != entry->in_pack_type)
 403                 to_reuse = 0;   /* pack has delta which is unusable */
 404         else if (entry->delta)
 405                 to_reuse = 0;   /* we want to pack afresh */
 406         else
 407                 to_reuse = 1;   /* we have it in-pack undeltified,
 408                                  * and we do not need to deltify it.
 409                                  */
 410
 411         if (!to_reuse) {
 412                 z_stream stream;
 413                 unsigned long maxsize;
 414                 void *out;
 415                 if (!usable_delta) {
 416                         buf = read_sha1_file(entry->idx.sha1, &obj_type, &size);
 417                         if (!buf)
 418                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 419                 } else if (entry->delta_data) {
 420                         size = entry->delta_size;
 421                         buf = entry->delta_data;
 422                         entry->delta_data = NULL;
 423                         obj_type = (allow_ofs_delta && entry->delta->idx.offset) ?
 424                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 425                 } else {
 426                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 427                         if (!buf)
 428                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 429                         buf = delta_against(buf, size, entry);
 430                         size = entry->delta_size;
 431                         obj_type = (allow_ofs_delta && entry->delta->idx.offset) ?
 432                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 433                 }
 434                 /* compress the data to store and put compressed length in datalen */
 435                 memset(&stream, 0, sizeof(stream));
 436                 deflateInit(&stream, pack_compression_level);
 437                 maxsize = deflateBound(&stream, size);
 438                 out = xmalloc(maxsize);
 439                 /* Compress it */
 440                 stream.next_in = buf;
 441                 stream.avail_in = size;
 442                 stream.next_out = out;
 443                 stream.avail_out = maxsize;
 444                 while (deflate(&stream, Z_FINISH) == Z_OK)
 445                         /* nothing */;
 446                 deflateEnd(&stream);
 447                 datalen = stream.total_out;
 448                 deflateEnd(&stream);
 449                 /*
 450                  * The object header is a byte of 'type' followed by zero or
 451                  * more bytes of length.
 452                  */
 453                 hdrlen = encode_header(obj_type, size, header);
 454
 455                 if (obj_type == OBJ_OFS_DELTA) {
 456                         /*
 457                          * Deltas with relative base contain an additional
 458                          * encoding of the relative offset for the delta
 459                          * base from this object's position in the pack.
 460                          */
 461                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 462                         unsigned pos = sizeof(dheader) - 1;
 463                         dheader[pos] = ofs & 127;
 464                         while (ofs >>= 7)
 465                                 dheader[--pos] = 128 | (--ofs & 127);
 466                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 467                                 free(out);
 468                                 free(buf);
 469                                 return 0;
 470                         }
 471                         sha1write(f, header, hdrlen);
 472                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 473                         hdrlen += sizeof(dheader) - pos;
 474                 } else if (obj_type == OBJ_REF_DELTA) {
 475                         /*
 476                          * Deltas with a base reference contain
 477                          * an additional 20 bytes for the base sha1.
 478                          */
 479                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 480                                 free(out);
 481                                 free(buf);
 482                                 return 0;
 483                         }
 484                         sha1write(f, header, hdrlen);
 485                         sha1write(f, entry->delta->idx.sha1, 20);
 486                         hdrlen += 20;
 487                 } else {
 488                         if (limit && hdrlen + datalen + 20 >= limit) {
 489                                 free(out);
 490                                 free(buf);
 491                                 return 0;
 492                         }
 493                         sha1write(f, header, hdrlen);
 494                 }
 495                 sha1write(f, out, datalen);
 496                 free(out);
 497                 free(buf);
 498         }
 499         else {
 500                 struct packed_git *p = entry->in_pack;
 501                 struct pack_window *w_curs = NULL;
 502                 struct revindex_entry *revidx;
 503                 off_t offset;
 504
 505                 if (entry->delta) {
 506                         obj_type = (allow_ofs_delta && entry->delta->idx.offset) ?
 507                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 508                         reused_delta++;
 509                 }
 510                 hdrlen = encode_header(obj_type, entry->size, header);
 511                 offset = entry->in_pack_offset;
 512                 revidx = find_packed_object(p, offset);
 513                 datalen = revidx[1].offset - offset;
 514                 if (!pack_to_stdout && p->index_version > 1 &&
 515                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
 516                         die("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 517                 offset += entry->in_pack_header_size;
 518                 datalen -= entry->in_pack_header_size;
 519                 if (obj_type == OBJ_OFS_DELTA) {
 520                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 521                         unsigned pos = sizeof(dheader) - 1;
 522                         dheader[pos] = ofs & 127;
 523                         while (ofs >>= 7)
 524                                 dheader[--pos] = 128 | (--ofs & 127);
 525                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit)
 526                                 return 0;
 527                         sha1write(f, header, hdrlen);
 528                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 529                         hdrlen += sizeof(dheader) - pos;
 530                 } else if (obj_type == OBJ_REF_DELTA) {
 531                         if (limit && hdrlen + 20 + datalen + 20 >= limit)
 532                                 return 0;
 533                         sha1write(f, header, hdrlen);
 534                         sha1write(f, entry->delta->idx.sha1, 20);
 535                         hdrlen += 20;
 536                 } else {
 537                         if (limit && hdrlen + datalen + 20 >= limit)
 538                                 return 0;
 539                         sha1write(f, header, hdrlen);
 540                 }
 541
 542                 if (!pack_to_stdout && p->index_version == 1 &&
 543                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
 544                         die("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 545                 copy_pack_data(f, p, &w_curs, offset, datalen);
 546                 unuse_pack(&w_curs);
 547                 reused++;
 548         }
 549         if (usable_delta)
 550                 written_delta++;
 551         written++;
 552         if (!pack_to_stdout)
 553                 entry->idx.crc32 = crc32_end(f);
 554         return hdrlen + datalen;
 555 }
 556
 557 static off_t write_one(struct sha1file *f,
 558                                struct object_entry *e,
 559                                off_t offset)
 560 {
 561         unsigned long size;
 562
 563         /* offset is non zero if object is written already. */
 564         if (e->idx.offset || e->preferred_base)
 565                 return offset;
 566
 567         /* if we are deltified, write out base object first. */
 568         if (e->delta) {
 569                 offset = write_one(f, e->delta, offset);
 570                 if (!offset)
 571                         return 0;
 572         }
 573
 574         e->idx.offset = offset;
 575         size = write_object(f, e, offset);
 576         if (!size) {
 577                 e->idx.offset = 0;
 578                 return 0;
 579         }
 580         written_list[nr_written++] = e;
 581
 582         /* make sure off_t is sufficiently large not to wrap */
 583         if (offset > offset + size)
 584                 die("pack too large for current definition of off_t");
 585         return offset + size;
 586 }
 587
 588 /* forward declaration for write_pack_file */
 589 static int adjust_perm(const char *path, mode_t mode);
 590
 591 static void write_pack_file(void)
 592 {
 593         uint32_t i = 0, j;
 594         struct sha1file *f;
 595         off_t offset, offset_one, last_obj_offset = 0;
 596         struct pack_header hdr;
 597         int do_progress = progress >> pack_to_stdout;
 598         uint32_t nr_remaining = nr_result;
 599
 600         if (do_progress)
 601                 start_progress(&progress_state, "Writing objects", nr_result);
 602         written_list = xmalloc(nr_objects * sizeof(struct object_entry *));
 603
 604         do {
 605                 unsigned char sha1[20];
 606                 char *pack_tmp_name = NULL;
 607
 608                 if (pack_to_stdout) {
 609                         f = sha1fd(1, "<stdout>");
 610                 } else {
 611                         char tmpname[PATH_MAX];
 612                         int fd;
 613                         snprintf(tmpname, sizeof(tmpname),
 614                                  "%s/tmp_pack_XXXXXX", get_object_directory());
 615                         fd = xmkstemp(tmpname);
 616                         pack_tmp_name = xstrdup(tmpname);
 617                         f = sha1fd(fd, pack_tmp_name);
 618                 }
 619
 620                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
 621                 hdr.hdr_version = htonl(PACK_VERSION);
 622                 hdr.hdr_entries = htonl(nr_remaining);
 623                 sha1write(f, &hdr, sizeof(hdr));
 624                 offset = sizeof(hdr);
 625                 nr_written = 0;
 626                 for (; i < nr_objects; i++) {
 627                         last_obj_offset = offset;
 628                         offset_one = write_one(f, objects + i, offset);
 629                         if (!offset_one)
 630                                 break;
 631                         offset = offset_one;
 632                         if (do_progress)
 633                                 display_progress(&progress_state, written);
 634                 }
 635
 636                 /*
 637                  * Did we write the wrong # entries in the header?
 638                  * If so, rewrite it like in fast-import
 639                  */
 640                 if (pack_to_stdout || nr_written == nr_remaining) {
 641                         sha1close(f, sha1, 1);
 642                 } else {
 643                         int fd = sha1close(f, NULL, 0);
 644                         fixup_pack_header_footer(fd, sha1, pack_tmp_name, nr_written);
 645                         close(fd);
 646                 }
 647
 648                 if (!pack_to_stdout) {
 649                         mode_t mode = umask(0);
 650                         char *idx_tmp_name, tmpname[PATH_MAX];
 651
 652                         umask(mode);
 653                         mode = 0444 & ~mode;
 654
 655                         idx_tmp_name = write_idx_file(NULL,
 656                                         (struct pack_idx_entry **) written_list,
 657                                         nr_written, sha1);
 658                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 659                                  base_name, sha1_to_hex(sha1));
 660                         if (adjust_perm(pack_tmp_name, mode))
 661                                 die("unable to make temporary pack file readable: %s",
 662                                     strerror(errno));
 663                         if (rename(pack_tmp_name, tmpname))
 664                                 die("unable to rename temporary pack file: %s",
 665                                     strerror(errno));
 666                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 667                                  base_name, sha1_to_hex(sha1));
 668                         if (adjust_perm(idx_tmp_name, mode))
 669                                 die("unable to make temporary index file readable: %s",
 670                                     strerror(errno));
 671                         if (rename(idx_tmp_name, tmpname))
 672                                 die("unable to rename temporary index file: %s",
 673                                     strerror(errno));
 674                         free(idx_tmp_name);
 675                         free(pack_tmp_name);
 676                         puts(sha1_to_hex(sha1));
 677                 }
 678
 679                 /* mark written objects as written to previous pack */
 680                 for (j = 0; j < nr_written; j++) {
 681                         written_list[j]->idx.offset = (off_t)-1;
 682                 }
 683                 nr_remaining -= nr_written;
 684         } while (nr_remaining && i < nr_objects);
 685
 686         free(written_list);
 687         if (do_progress)
 688                 stop_progress(&progress_state);
 689         if (written != nr_result)
 690                 die("wrote %u objects while expecting %u", written, nr_result);
 691         /*
 692          * We have scanned through [0 ... i).  Since we have written
 693          * the correct number of objects,  the remaining [i ... nr_objects)
 694          * items must be either already written (due to out-of-order delta base)
 695          * or a preferred base.  Count those which are neither and complain if any.
 696          */
 697         for (j = 0; i < nr_objects; i++) {
 698                 struct object_entry *e = objects + i;
 699                 j += !e->idx.offset && !e->preferred_base;
 700         }
 701         if (j)
 702                 die("wrote %u objects as expected but %u unwritten", written, j);
 703 }
 704
 705 static int locate_object_entry_hash(const unsigned char *sha1)
 706 {
 707         int i;
 708         unsigned int ui;
 709         memcpy(&ui, sha1, sizeof(unsigned int));
 710         i = ui % object_ix_hashsz;
 711         while (0 < object_ix[i]) {
 712                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 713                         return i;
 714                 if (++i == object_ix_hashsz)
 715                         i = 0;
 716         }
 717         return -1 - i;
 718 }
 719
 720 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 721 {
 722         int i;
 723
 724         if (!object_ix_hashsz)
 725                 return NULL;
 726
 727         i = locate_object_entry_hash(sha1);
 728         if (0 <= i)
 729                 return &objects[object_ix[i]-1];
 730         return NULL;
 731 }
 732
 733 static void rehash_objects(void)
 734 {
 735         uint32_t i;
 736         struct object_entry *oe;
 737
 738         object_ix_hashsz = nr_objects * 3;
 739         if (object_ix_hashsz < 1024)
 740                 object_ix_hashsz = 1024;
 741         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 742         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 743         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 744                 int ix = locate_object_entry_hash(oe->idx.sha1);
 745                 if (0 <= ix)
 746                         continue;
 747                 ix = -1 - ix;
 748                 object_ix[ix] = i + 1;
 749         }
 750 }
 751
 752 static unsigned name_hash(const char *name)
 753 {
 754         unsigned char c;
 755         unsigned hash = 0;
 756
 757         if (!name)
 758                 return 0;
 759
 760         /*
 761          * This effectively just creates a sortable number from the
 762          * last sixteen non-whitespace characters. Last characters
 763          * count "most", so things that end in ".c" sort together.
 764          */
 765         while ((c = *name++) != 0) {
 766                 if (isspace(c))
 767                         continue;
 768                 hash = (hash >> 2) + (c << 24);
 769         }
 770         return hash;
 771 }
 772
 773 static void setup_delta_attr_check(struct git_attr_check *check)
 774 {
 775         static struct git_attr *attr_delta;
 776
 777         if (!attr_delta)
 778                 attr_delta = git_attr("delta", 5);
 779
 780         check[0].attr = attr_delta;
 781 }
 782
 783 static int no_try_delta(const char *path)
 784 {
 785         struct git_attr_check check[1];
 786
 787         setup_delta_attr_check(check);
 788         if (git_checkattr(path, ARRAY_SIZE(check), check))
 789                 return 0;
 790         if (ATTR_FALSE(check->value))
 791                 return 1;
 792         return 0;
 793 }
 794
 795 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 796                             const char *name, int exclude)
 797 {
 798         struct object_entry *entry;
 799         struct packed_git *p, *found_pack = NULL;
 800         off_t found_offset = 0;
 801         int ix;
 802         unsigned hash = name_hash(name);
 803
 804         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 805         if (ix >= 0) {
 806                 if (exclude) {
 807                         entry = objects + object_ix[ix] - 1;
 808                         if (!entry->preferred_base)
 809                                 nr_result--;
 810                         entry->preferred_base = 1;
 811                 }
 812                 return 0;
 813         }
 814
 815         for (p = packed_git; p; p = p->next) {
 816                 off_t offset = find_pack_entry_one(sha1, p);
 817                 if (offset) {
 818                         if (!found_pack) {
 819                                 found_offset = offset;
 820                                 found_pack = p;
 821                         }
 822                         if (exclude)
 823                                 break;
 824                         if (incremental)
 825                                 return 0;
 826                         if (local && !p->pack_local)
 827                                 return 0;
 828                 }
 829         }
 830
 831         if (nr_objects >= nr_alloc) {
 832                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 833                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 834         }
 835
 836         entry = objects + nr_objects++;
 837         memset(entry, 0, sizeof(*entry));
 838         hashcpy(entry->idx.sha1, sha1);
 839         entry->hash = hash;
 840         if (type)
 841                 entry->type = type;
 842         if (exclude)
 843                 entry->preferred_base = 1;
 844         else
 845                 nr_result++;
 846         if (found_pack) {
 847                 entry->in_pack = found_pack;
 848                 entry->in_pack_offset = found_offset;
 849         }
 850
 851         if (object_ix_hashsz * 3 <= nr_objects * 4)
 852                 rehash_objects();
 853         else
 854                 object_ix[-1 - ix] = nr_objects;
 855
 856         if (progress)
 857                 display_progress(&progress_state, nr_objects);
 858
 859         if (name && no_try_delta(name))
 860                 entry->no_try_delta = 1;
 861
 862         return 1;
 863 }
 864
 865 struct pbase_tree_cache {
 866         unsigned char sha1[20];
 867         int ref;
 868         int temporary;
 869         void *tree_data;
 870         unsigned long tree_size;
 871 };
 872
 873 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 874 static int pbase_tree_cache_ix(const unsigned char *sha1)
 875 {
 876         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 877 }
 878 static int pbase_tree_cache_ix_incr(int ix)
 879 {
 880         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 881 }
 882
 883 static struct pbase_tree {
 884         struct pbase_tree *next;
 885         /* This is a phony "cache" entry; we are not
 886          * going to evict it nor find it through _get()
 887          * mechanism -- this is for the toplevel node that
 888          * would almost always change with any commit.
 889          */
 890         struct pbase_tree_cache pcache;
 891 } *pbase_tree;
 892
 893 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 894 {
 895         struct pbase_tree_cache *ent, *nent;
 896         void *data;
 897         unsigned long size;
 898         enum object_type type;
 899         int neigh;
 900         int my_ix = pbase_tree_cache_ix(sha1);
 901         int available_ix = -1;
 902
 903         /* pbase-tree-cache acts as a limited hashtable.
 904          * your object will be found at your index or within a few
 905          * slots after that slot if it is cached.
 906          */
 907         for (neigh = 0; neigh < 8; neigh++) {
 908                 ent = pbase_tree_cache[my_ix];
 909                 if (ent && !hashcmp(ent->sha1, sha1)) {
 910                         ent->ref++;
 911                         return ent;
 912                 }
 913                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 914                          ((0 <= available_ix) &&
 915                           (!ent && pbase_tree_cache[available_ix])))
 916                         available_ix = my_ix;
 917                 if (!ent)
 918                         break;
 919                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 920         }
 921
 922         /* Did not find one.  Either we got a bogus request or
 923          * we need to read and perhaps cache.
 924          */
 925         data = read_sha1_file(sha1, &type, &size);
 926         if (!data)
 927                 return NULL;
 928         if (type != OBJ_TREE) {
 929                 free(data);
 930                 return NULL;
 931         }
 932
 933         /* We need to either cache or return a throwaway copy */
 934
 935         if (available_ix < 0)
 936                 ent = NULL;
 937         else {
 938                 ent = pbase_tree_cache[available_ix];
 939                 my_ix = available_ix;
 940         }
 941
 942         if (!ent) {
 943                 nent = xmalloc(sizeof(*nent));
 944                 nent->temporary = (available_ix < 0);
 945         }
 946         else {
 947                 /* evict and reuse */
 948                 free(ent->tree_data);
 949                 nent = ent;
 950         }
 951         hashcpy(nent->sha1, sha1);
 952         nent->tree_data = data;
 953         nent->tree_size = size;
 954         nent->ref = 1;
 955         if (!nent->temporary)
 956                 pbase_tree_cache[my_ix] = nent;
 957         return nent;
 958 }
 959
 960 static void pbase_tree_put(struct pbase_tree_cache *cache)
 961 {
 962         if (!cache->temporary) {
 963                 cache->ref--;
 964                 return;
 965         }
 966         free(cache->tree_data);
 967         free(cache);
 968 }
 969
 970 static int name_cmp_len(const char *name)
 971 {
 972         int i;
 973         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 974                 ;
 975         return i;
 976 }
 977
 978 static void add_pbase_object(struct tree_desc *tree,
 979                              const char *name,
 980                              int cmplen,
 981                              const char *fullname)
 982 {
 983         struct name_entry entry;
 984         int cmp;
 985
 986         while (tree_entry(tree,&entry)) {
 987                 if (S_ISGITLINK(entry.mode))
 988                         continue;
 989                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 990                       memcmp(name, entry.path, cmplen);
 991                 if (cmp > 0)
 992                         continue;
 993                 if (cmp < 0)
 994                         return;
 995                 if (name[cmplen] != '/') {
 996                         add_object_entry(entry.sha1,
 997                                          S_ISDIR(entry.mode) ? OBJ_TREE : OBJ_BLOB,
 998                                          fullname, 1);
 999                         return;
1000                 }
1001                 if (S_ISDIR(entry.mode)) {
1002                         struct tree_desc sub;
1003                         struct pbase_tree_cache *tree;
1004                         const char *down = name+cmplen+1;
1005                         int downlen = name_cmp_len(down);
1006
1007                         tree = pbase_tree_get(entry.sha1);
1008                         if (!tree)
1009                                 return;
1010                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1011
1012                         add_pbase_object(&sub, down, downlen, fullname);
1013                         pbase_tree_put(tree);
1014                 }
1015         }
1016 }
1017
1018 static unsigned *done_pbase_paths;
1019 static int done_pbase_paths_num;
1020 static int done_pbase_paths_alloc;
1021 static int done_pbase_path_pos(unsigned hash)
1022 {
1023         int lo = 0;
1024         int hi = done_pbase_paths_num;
1025         while (lo < hi) {
1026                 int mi = (hi + lo) / 2;
1027                 if (done_pbase_paths[mi] == hash)
1028                         return mi;
1029                 if (done_pbase_paths[mi] < hash)
1030                         hi = mi;
1031                 else
1032                         lo = mi + 1;
1033         }
1034         return -lo-1;
1035 }
1036
1037 static int check_pbase_path(unsigned hash)
1038 {
1039         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
1040         if (0 <= pos)
1041                 return 1;
1042         pos = -pos - 1;
1043         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
1044                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
1045                 done_pbase_paths = xrealloc(done_pbase_paths,
1046                                             done_pbase_paths_alloc *
1047                                             sizeof(unsigned));
1048         }
1049         done_pbase_paths_num++;
1050         if (pos < done_pbase_paths_num)
1051                 memmove(done_pbase_paths + pos + 1,
1052                         done_pbase_paths + pos,
1053                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
1054         done_pbase_paths[pos] = hash;
1055         return 0;
1056 }
1057
1058 static void add_preferred_base_object(const char *name)
1059 {
1060         struct pbase_tree *it;
1061         int cmplen;
1062         unsigned hash = name_hash(name);
1063
1064         if (!num_preferred_base || check_pbase_path(hash))
1065                 return;
1066
1067         cmplen = name_cmp_len(name);
1068         for (it = pbase_tree; it; it = it->next) {
1069                 if (cmplen == 0) {
1070                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
1071                 }
1072                 else {
1073                         struct tree_desc tree;
1074                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1075                         add_pbase_object(&tree, name, cmplen, name);
1076                 }
1077         }
1078 }
1079
1080 static void add_preferred_base(unsigned char *sha1)
1081 {
1082         struct pbase_tree *it;
1083         void *data;
1084         unsigned long size;
1085         unsigned char tree_sha1[20];
1086
1087         if (window <= num_preferred_base++)
1088                 return;
1089
1090         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
1091         if (!data)
1092                 return;
1093
1094         for (it = pbase_tree; it; it = it->next) {
1095                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
1096                         free(data);
1097                         return;
1098                 }
1099         }
1100
1101         it = xcalloc(1, sizeof(*it));
1102         it->next = pbase_tree;
1103         pbase_tree = it;
1104
1105         hashcpy(it->pcache.sha1, tree_sha1);
1106         it->pcache.tree_data = data;
1107         it->pcache.tree_size = size;
1108 }
1109
1110 static void check_object(struct object_entry *entry)
1111 {
1112         if (entry->in_pack) {
1113                 struct packed_git *p = entry->in_pack;
1114                 struct pack_window *w_curs = NULL;
1115                 const unsigned char *base_ref = NULL;
1116                 struct object_entry *base_entry;
1117                 unsigned long used, used_0;
1118                 unsigned int avail;
1119                 off_t ofs;
1120                 unsigned char *buf, c;
1121
1122                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1123
1124                 /*
1125                  * We want in_pack_type even if we do not reuse delta
1126                  * since non-delta representations could still be reused.
1127                  */
1128                 used = unpack_object_header_gently(buf, avail,
1129                                                    &entry->in_pack_type,
1130                                                    &entry->size);
1131
1132                 /*
1133                  * Determine if this is a delta and if so whether we can
1134                  * reuse it or not.  Otherwise let's find out as cheaply as
1135                  * possible what the actual type and size for this object is.
1136                  */
1137                 switch (entry->in_pack_type) {
1138                 default:
1139                         /* Not a delta hence we've already got all we need. */
1140                         entry->type = entry->in_pack_type;
1141                         entry->in_pack_header_size = used;
1142                         unuse_pack(&w_curs);
1143                         return;
1144                 case OBJ_REF_DELTA:
1145                         if (!no_reuse_delta && !entry->preferred_base)
1146                                 base_ref = use_pack(p, &w_curs,
1147                                                 entry->in_pack_offset + used, NULL);
1148                         entry->in_pack_header_size = used + 20;
1149                         break;
1150                 case OBJ_OFS_DELTA:
1151                         buf = use_pack(p, &w_curs,
1152                                        entry->in_pack_offset + used, NULL);
1153                         used_0 = 0;
1154                         c = buf[used_0++];
1155                         ofs = c & 127;
1156                         while (c & 128) {
1157                                 ofs += 1;
1158                                 if (!ofs || MSB(ofs, 7))
1159                                         die("delta base offset overflow in pack for %s",
1160                                             sha1_to_hex(entry->idx.sha1));
1161                                 c = buf[used_0++];
1162                                 ofs = (ofs << 7) + (c & 127);
1163                         }
1164                         if (ofs >= entry->in_pack_offset)
1165                                 die("delta base offset out of bound for %s",
1166                                     sha1_to_hex(entry->idx.sha1));
1167                         ofs = entry->in_pack_offset - ofs;
1168                         if (!no_reuse_delta && !entry->preferred_base)
1169                                 base_ref = find_packed_object_name(p, ofs);
1170                         entry->in_pack_header_size = used + used_0;
1171                         break;
1172                 }
1173
1174                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1175                         /*
1176                          * If base_ref was set above that means we wish to
1177                          * reuse delta data, and we even found that base
1178                          * in the list of objects we want to pack. Goodie!
1179                          *
1180                          * Depth value does not matter - find_deltas() will
1181                          * never consider reused delta as the base object to
1182                          * deltify other objects against, in order to avoid
1183                          * circular deltas.
1184                          */
1185                         entry->type = entry->in_pack_type;
1186                         entry->delta = base_entry;
1187                         entry->delta_sibling = base_entry->delta_child;
1188                         base_entry->delta_child = entry;
1189                         unuse_pack(&w_curs);
1190                         return;
1191                 }
1192
1193                 if (entry->type) {
1194                         /*
1195                          * This must be a delta and we already know what the
1196                          * final object type is.  Let's extract the actual
1197                          * object size from the delta header.
1198                          */
1199                         entry->size = get_size_from_delta(p, &w_curs,
1200                                         entry->in_pack_offset + entry->in_pack_header_size);
1201                         unuse_pack(&w_curs);
1202                         return;
1203                 }
1204
1205                 /*
1206                  * No choice but to fall back to the recursive delta walk
1207                  * with sha1_object_info() to find about the object type
1208                  * at this point...
1209                  */
1210                 unuse_pack(&w_curs);
1211         }
1212
1213         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1214         if (entry->type < 0)
1215                 die("unable to get type of object %s",
1216                     sha1_to_hex(entry->idx.sha1));
1217 }
1218
1219 static int pack_offset_sort(const void *_a, const void *_b)
1220 {
1221         const struct object_entry *a = *(struct object_entry **)_a;
1222         const struct object_entry *b = *(struct object_entry **)_b;
1223
1224         /* avoid filesystem trashing with loose objects */
1225         if (!a->in_pack && !b->in_pack)
1226                 return hashcmp(a->idx.sha1, b->idx.sha1);
1227
1228         if (a->in_pack < b->in_pack)
1229                 return -1;
1230         if (a->in_pack > b->in_pack)
1231                 return 1;
1232         return a->in_pack_offset < b->in_pack_offset ? -1 :
1233                         (a->in_pack_offset > b->in_pack_offset);
1234 }
1235
1236 static void get_object_details(void)
1237 {
1238         uint32_t i;
1239         struct object_entry **sorted_by_offset;
1240
1241         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1242         for (i = 0; i < nr_objects; i++)
1243                 sorted_by_offset[i] = objects + i;
1244         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1245
1246         prepare_pack_ix();
1247         for (i = 0; i < nr_objects; i++)
1248                 check_object(sorted_by_offset[i]);
1249         free(sorted_by_offset);
1250 }
1251
1252 static int type_size_sort(const void *_a, const void *_b)
1253 {
1254         const struct object_entry *a = *(struct object_entry **)_a;
1255         const struct object_entry *b = *(struct object_entry **)_b;
1256
1257         if (a->type < b->type)
1258                 return -1;
1259         if (a->type > b->type)
1260                 return 1;
1261         if (a->hash < b->hash)
1262                 return -1;
1263         if (a->hash > b->hash)
1264                 return 1;
1265         if (a->preferred_base < b->preferred_base)
1266                 return -1;
1267         if (a->preferred_base > b->preferred_base)
1268                 return 1;
1269         if (a->size < b->size)
1270                 return -1;
1271         if (a->size > b->size)
1272                 return 1;
1273         return a > b ? -1 : (a < b);  /* newest last */
1274 }
1275
1276 struct unpacked {
1277         struct object_entry *entry;
1278         void *data;
1279         struct delta_index *index;
1280         unsigned depth;
1281 };
1282
1283 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1284                            unsigned long delta_size)
1285 {
1286         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1287                 return 0;
1288
1289         if (delta_size < cache_max_small_delta_size)
1290                 return 1;
1291
1292         /* cache delta, if objects are large enough compared to delta size */
1293         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1294                 return 1;
1295
1296         return 0;
1297 }
1298
1299 #ifdef THREADED_DELTA_SEARCH
1300
1301 static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1302 #define read_lock()             pthread_mutex_lock(&read_mutex)
1303 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1304
1305 static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1306 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1307 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1308
1309 static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1310 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1311 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1312
1313 #else
1314
1315 #define read_lock()             (void)0
1316 #define read_unlock()           (void)0
1317 #define cache_lock()            (void)0
1318 #define cache_unlock()          (void)0
1319 #define progress_lock()         (void)0
1320 #define progress_unlock()       (void)0
1321
1322 #endif
1323
1324 /*
1325  * We search for deltas _backwards_ in a list sorted by type and
1326  * by size, so that we see progressively smaller and smaller files.
1327  * That's because we prefer deltas to be from the bigger file
1328  * to the smaller - deletes are potentially cheaper, but perhaps
1329  * more importantly, the bigger file is likely the more recent
1330  * one.
1331  */
1332 static int try_delta(struct unpacked *trg, struct unpacked *src,
1333                      unsigned max_depth, unsigned long *mem_usage)
1334 {
1335         struct object_entry *trg_entry = trg->entry;
1336         struct object_entry *src_entry = src->entry;
1337         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1338         unsigned ref_depth;
1339         enum object_type type;
1340         void *delta_buf;
1341
1342         /* Don't bother doing diffs between different types */
1343         if (trg_entry->type != src_entry->type)
1344                 return -1;
1345
1346         /*
1347          * We do not bother to try a delta that we discarded
1348          * on an earlier try, but only when reusing delta data.
1349          */
1350         if (!no_reuse_delta && trg_entry->in_pack &&
1351             trg_entry->in_pack == src_entry->in_pack &&
1352             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1353             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1354                 return 0;
1355
1356         /* Let's not bust the allowed depth. */
1357         if (src->depth >= max_depth)
1358                 return 0;
1359
1360         /* Now some size filtering heuristics. */
1361         trg_size = trg_entry->size;
1362         if (!trg_entry->delta) {
1363                 max_size = trg_size/2 - 20;
1364                 ref_depth = 1;
1365         } else {
1366                 max_size = trg_entry->delta_size;
1367                 ref_depth = trg->depth;
1368         }
1369         max_size = max_size * (max_depth - src->depth) /
1370                                                 (max_depth - ref_depth + 1);
1371         if (max_size == 0)
1372                 return 0;
1373         src_size = src_entry->size;
1374         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1375         if (sizediff >= max_size)
1376                 return 0;
1377         if (trg_size < src_size / 32)
1378                 return 0;
1379
1380         /* Load data if not already done */
1381         if (!trg->data) {
1382                 read_lock();
1383                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1384                 read_unlock();
1385                 if (!trg->data)
1386                         die("object %s cannot be read",
1387                             sha1_to_hex(trg_entry->idx.sha1));
1388                 if (sz != trg_size)
1389                         die("object %s inconsistent object length (%lu vs %lu)",
1390                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1391                 *mem_usage += sz;
1392         }
1393         if (!src->data) {
1394                 read_lock();
1395                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1396                 read_unlock();
1397                 if (!src->data)
1398                         die("object %s cannot be read",
1399                             sha1_to_hex(src_entry->idx.sha1));
1400                 if (sz != src_size)
1401                         die("object %s inconsistent object length (%lu vs %lu)",
1402                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1403                 *mem_usage += sz;
1404         }
1405         if (!src->index) {
1406                 src->index = create_delta_index(src->data, src_size);
1407                 if (!src->index) {
1408                         static int warned = 0;
1409                         if (!warned++)
1410                                 warning("suboptimal pack - out of memory");
1411                         return 0;
1412                 }
1413                 *mem_usage += sizeof_delta_index(src->index);
1414         }
1415
1416         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1417         if (!delta_buf)
1418                 return 0;
1419
1420         if (trg_entry->delta) {
1421                 /* Prefer only shallower same-sized deltas. */
1422                 if (delta_size == trg_entry->delta_size &&
1423                     src->depth + 1 >= trg->depth) {
1424                         free(delta_buf);
1425                         return 0;
1426                 }
1427         }
1428
1429         trg_entry->delta = src_entry;
1430         trg_entry->delta_size = delta_size;
1431         trg->depth = src->depth + 1;
1432
1433         /*
1434          * Handle memory allocation outside of the cache
1435          * accounting lock.  Compiler will optimize the strangeness
1436          * away when THREADED_DELTA_SEARCH is not defined.
1437          */
1438         if (trg_entry->delta_data)
1439                 free(trg_entry->delta_data);
1440         cache_lock();
1441         if (trg_entry->delta_data) {
1442                 delta_cache_size -= trg_entry->delta_size;
1443                 trg_entry->delta_data = NULL;
1444         }
1445         if (delta_cacheable(src_size, trg_size, delta_size)) {
1446                 delta_cache_size += trg_entry->delta_size;
1447                 cache_unlock();
1448                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1449         } else {
1450                 cache_unlock();
1451                 free(delta_buf);
1452         }
1453
1454         return 1;
1455 }
1456
1457 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1458 {
1459         struct object_entry *child = me->delta_child;
1460         unsigned int m = n;
1461         while (child) {
1462                 unsigned int c = check_delta_limit(child, n + 1);
1463                 if (m < c)
1464                         m = c;
1465                 child = child->delta_sibling;
1466         }
1467         return m;
1468 }
1469
1470 static unsigned long free_unpacked(struct unpacked *n)
1471 {
1472         unsigned long freed_mem = sizeof_delta_index(n->index);
1473         free_delta_index(n->index);
1474         n->index = NULL;
1475         if (n->data) {
1476                 freed_mem += n->entry->size;
1477                 free(n->data);
1478                 n->data = NULL;
1479         }
1480         n->entry = NULL;
1481         n->depth = 0;
1482         return freed_mem;
1483 }
1484
1485 static void find_deltas(struct object_entry **list, unsigned list_size,
1486                         int window, int depth, unsigned *processed)
1487 {
1488         uint32_t i = list_size, idx = 0, count = 0;
1489         unsigned int array_size = window * sizeof(struct unpacked);
1490         struct unpacked *array;
1491         unsigned long mem_usage = 0;
1492
1493         array = xmalloc(array_size);
1494         memset(array, 0, array_size);
1495
1496         do {
1497                 struct object_entry *entry = list[--i];
1498                 struct unpacked *n = array + idx;
1499                 int j, max_depth, best_base = -1;
1500
1501                 mem_usage -= free_unpacked(n);
1502                 n->entry = entry;
1503
1504                 while (window_memory_limit &&
1505                        mem_usage > window_memory_limit &&
1506                        count > 1) {
1507                         uint32_t tail = (idx + window - count) % window;
1508                         mem_usage -= free_unpacked(array + tail);
1509                         count--;
1510                 }
1511
1512                 /* We do not compute delta to *create* objects we are not
1513                  * going to pack.
1514                  */
1515                 if (entry->preferred_base)
1516                         goto next;
1517
1518                 progress_lock();
1519                 (*processed)++;
1520                 if (progress)
1521                         display_progress(&progress_state, *processed);
1522                 progress_unlock();
1523
1524                 /*
1525                  * If the current object is at pack edge, take the depth the
1526                  * objects that depend on the current object into account
1527                  * otherwise they would become too deep.
1528                  */
1529                 max_depth = depth;
1530                 if (entry->delta_child) {
1531                         max_depth -= check_delta_limit(entry, 0);
1532                         if (max_depth <= 0)
1533                                 goto next;
1534                 }
1535
1536                 j = window;
1537                 while (--j > 0) {
1538                         int ret;
1539                         uint32_t other_idx = idx + j;
1540                         struct unpacked *m;
1541                         if (other_idx >= window)
1542                                 other_idx -= window;
1543                         m = array + other_idx;
1544                         if (!m->entry)
1545                                 break;
1546                         ret = try_delta(n, m, max_depth, &mem_usage);
1547                         if (ret < 0)
1548                                 break;
1549                         else if (ret > 0)
1550                                 best_base = other_idx;
1551                 }
1552
1553                 /* if we made n a delta, and if n is already at max
1554                  * depth, leaving it in the window is pointless.  we
1555                  * should evict it first.
1556                  */
1557                 if (entry->delta && depth <= n->depth)
1558                         continue;
1559
1560                 /*
1561                  * Move the best delta base up in the window, after the
1562                  * currently deltified object, to keep it longer.  It will
1563                  * be the first base object to be attempted next.
1564                  */
1565                 if (entry->delta) {
1566                         struct unpacked swap = array[best_base];
1567                         int dist = (window + idx - best_base) % window;
1568                         int dst = best_base;
1569                         while (dist--) {
1570                                 int src = (dst + 1) % window;
1571                                 array[dst] = array[src];
1572                                 dst = src;
1573                         }
1574                         array[dst] = swap;
1575                 }
1576
1577                 next:
1578                 idx++;
1579                 if (count + 1 < window)
1580                         count++;
1581                 if (idx >= window)
1582                         idx = 0;
1583         } while (i > 0);
1584
1585         for (i = 0; i < window; ++i) {
1586                 free_delta_index(array[i].index);
1587                 free(array[i].data);
1588         }
1589         free(array);
1590 }
1591
1592 #ifdef THREADED_DELTA_SEARCH
1593
1594 struct thread_params {
1595         pthread_t thread;
1596         struct object_entry **list;
1597         unsigned list_size;
1598         int window;
1599         int depth;
1600         unsigned *processed;
1601 };
1602
1603 static pthread_mutex_t data_request  = PTHREAD_MUTEX_INITIALIZER;
1604 static pthread_mutex_t data_ready    = PTHREAD_MUTEX_INITIALIZER;
1605 static pthread_mutex_t data_provider = PTHREAD_MUTEX_INITIALIZER;
1606 static struct thread_params *data_requester;
1607
1608 static void *threaded_find_deltas(void *arg)
1609 {
1610         struct thread_params *me = arg;
1611
1612         for (;;) {
1613                 pthread_mutex_lock(&data_request);
1614                 data_requester = me;
1615                 pthread_mutex_unlock(&data_provider);
1616                 pthread_mutex_lock(&data_ready);
1617                 pthread_mutex_unlock(&data_request);
1618
1619                 if (!me->list_size)
1620                         return NULL;
1621
1622                 find_deltas(me->list, me->list_size,
1623                             me->window, me->depth, me->processed);
1624         }
1625 }
1626
1627 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1628                            int window, int depth, unsigned *processed)
1629 {
1630         struct thread_params *target, p[delta_search_threads];
1631         int i, ret;
1632         unsigned chunk_size;
1633
1634         if (delta_search_threads <= 1) {
1635                 find_deltas(list, list_size, window, depth, processed);
1636                 return;
1637         }
1638
1639         pthread_mutex_lock(&data_provider);
1640         pthread_mutex_lock(&data_ready);
1641
1642         for (i = 0; i < delta_search_threads; i++) {
1643                 p[i].window = window;
1644                 p[i].depth = depth;
1645                 p[i].processed = processed;
1646                 ret = pthread_create(&p[i].thread, NULL,
1647                                      threaded_find_deltas, &p[i]);
1648                 if (ret)
1649                         die("unable to create thread: %s", strerror(ret));
1650         }
1651
1652         /* this should be auto-tuned somehow */
1653         chunk_size = window * 1000;
1654
1655         do {
1656                 unsigned sublist_size = chunk_size;
1657                 if (sublist_size > list_size)
1658                         sublist_size = list_size;
1659
1660                 /* try to split chunks on "path" boundaries */
1661                 while (sublist_size < list_size && list[sublist_size]->hash &&
1662                        list[sublist_size]->hash == list[sublist_size-1]->hash)
1663                         sublist_size++;
1664
1665                 pthread_mutex_lock(&data_provider);
1666                 target = data_requester;
1667                 target->list = list;
1668                 target->list_size = sublist_size;
1669                 pthread_mutex_unlock(&data_ready);
1670
1671                 list += sublist_size;
1672                 list_size -= sublist_size;
1673                 if (!sublist_size) {
1674                         pthread_join(target->thread, NULL);
1675                         i--;
1676                 }
1677         } while (i);
1678 }
1679
1680 #else
1681 #define ll_find_deltas find_deltas
1682 #endif
1683
1684 static void prepare_pack(int window, int depth)
1685 {
1686         struct object_entry **delta_list;
1687         uint32_t i, n, nr_deltas;
1688
1689         get_object_details();
1690
1691         if (!nr_objects || !window || !depth)
1692                 return;
1693
1694         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1695         nr_deltas = n = 0;
1696
1697         for (i = 0; i < nr_objects; i++) {
1698                 struct object_entry *entry = objects + i;
1699
1700                 if (entry->delta)
1701                         /* This happens if we decided to reuse existing
1702                          * delta from a pack.  "!no_reuse_delta &&" is implied.
1703                          */
1704                         continue;
1705
1706                 if (entry->size < 50)
1707                         continue;
1708
1709                 if (entry->no_try_delta)
1710                         continue;
1711
1712                 if (!entry->preferred_base)
1713                         nr_deltas++;
1714
1715                 delta_list[n++] = entry;
1716         }
1717
1718         if (nr_deltas && n > 1) {
1719                 unsigned nr_done = 0;
1720                 if (progress)
1721                         start_progress(&progress_state, "Compressing objects",
1722                                         nr_deltas);
1723                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1724                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1725                 if (progress)
1726                         stop_progress(&progress_state);
1727                 if (nr_done != nr_deltas)
1728                         die("inconsistency with delta count");
1729         }
1730         free(delta_list);
1731 }
1732
1733 static int git_pack_config(const char *k, const char *v)
1734 {
1735         if(!strcmp(k, "pack.window")) {
1736                 window = git_config_int(k, v);
1737                 return 0;
1738         }
1739         if (!strcmp(k, "pack.windowmemory")) {
1740                 window_memory_limit = git_config_ulong(k, v);
1741                 return 0;
1742         }
1743         if (!strcmp(k, "pack.depth")) {
1744                 depth = git_config_int(k, v);
1745                 return 0;
1746         }
1747         if (!strcmp(k, "pack.compression")) {
1748                 int level = git_config_int(k, v);
1749                 if (level == -1)
1750                         level = Z_DEFAULT_COMPRESSION;
1751                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1752                         die("bad pack compression level %d", level);
1753                 pack_compression_level = level;
1754                 pack_compression_seen = 1;
1755                 return 0;
1756         }
1757         if (!strcmp(k, "pack.deltacachesize")) {
1758                 max_delta_cache_size = git_config_int(k, v);
1759                 return 0;
1760         }
1761         if (!strcmp(k, "pack.deltacachelimit")) {
1762                 cache_max_small_delta_size = git_config_int(k, v);
1763                 return 0;
1764         }
1765         if (!strcmp(k, "pack.threads")) {
1766                 delta_search_threads = git_config_int(k, v);
1767                 if (delta_search_threads < 1)
1768                         die("invalid number of threads specified (%d)",
1769                             delta_search_threads);
1770 #ifndef THREADED_DELTA_SEARCH
1771                 if (delta_search_threads > 1)
1772                         warning("no threads support, ignoring %s", k);
1773 #endif
1774                 return 0;
1775         }
1776         return git_default_config(k, v);
1777 }
1778
1779 static void read_object_list_from_stdin(void)
1780 {
1781         char line[40 + 1 + PATH_MAX + 2];
1782         unsigned char sha1[20];
1783
1784         for (;;) {
1785                 if (!fgets(line, sizeof(line), stdin)) {
1786                         if (feof(stdin))
1787                                 break;
1788                         if (!ferror(stdin))
1789                                 die("fgets returned NULL, not EOF, not error!");
1790                         if (errno != EINTR)
1791                                 die("fgets: %s", strerror(errno));
1792                         clearerr(stdin);
1793                         continue;
1794                 }
1795                 if (line[0] == '-') {
1796                         if (get_sha1_hex(line+1, sha1))
1797                                 die("expected edge sha1, got garbage:\n %s",
1798                                     line);
1799                         add_preferred_base(sha1);
1800                         continue;
1801                 }
1802                 if (get_sha1_hex(line, sha1))
1803                         die("expected sha1, got garbage:\n %s", line);
1804
1805                 add_preferred_base_object(line+41);
1806                 add_object_entry(sha1, 0, line+41, 0);
1807         }
1808 }
1809
1810 #define OBJECT_ADDED (1u<<20)
1811
1812 static void show_commit(struct commit *commit)
1813 {
1814         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1815         commit->object.flags |= OBJECT_ADDED;
1816 }
1817
1818 static void show_object(struct object_array_entry *p)
1819 {
1820         add_preferred_base_object(p->name);
1821         add_object_entry(p->item->sha1, p->item->type, p->name, 0);
1822         p->item->flags |= OBJECT_ADDED;
1823 }
1824
1825 static void show_edge(struct commit *commit)
1826 {
1827         add_preferred_base(commit->object.sha1);
1828 }
1829
1830 struct in_pack_object {
1831         off_t offset;
1832         struct object *object;
1833 };
1834
1835 struct in_pack {
1836         int alloc;
1837         int nr;
1838         struct in_pack_object *array;
1839 };
1840
1841 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1842 {
1843         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1844         in_pack->array[in_pack->nr].object = object;
1845         in_pack->nr++;
1846 }
1847
1848 /*
1849  * Compare the objects in the offset order, in order to emulate the
1850  * "git-rev-list --objects" output that produced the pack originally.
1851  */
1852 static int ofscmp(const void *a_, const void *b_)
1853 {
1854         struct in_pack_object *a = (struct in_pack_object *)a_;
1855         struct in_pack_object *b = (struct in_pack_object *)b_;
1856
1857         if (a->offset < b->offset)
1858                 return -1;
1859         else if (a->offset > b->offset)
1860                 return 1;
1861         else
1862                 return hashcmp(a->object->sha1, b->object->sha1);
1863 }
1864
1865 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1866 {
1867         struct packed_git *p;
1868         struct in_pack in_pack;
1869         uint32_t i;
1870
1871         memset(&in_pack, 0, sizeof(in_pack));
1872
1873         for (p = packed_git; p; p = p->next) {
1874                 const unsigned char *sha1;
1875                 struct object *o;
1876
1877                 for (i = 0; i < revs->num_ignore_packed; i++) {
1878                         if (matches_pack_name(p, revs->ignore_packed[i]))
1879                                 break;
1880                 }
1881                 if (revs->num_ignore_packed <= i)
1882                         continue;
1883                 if (open_pack_index(p))
1884                         die("cannot open pack index");
1885
1886                 ALLOC_GROW(in_pack.array,
1887                            in_pack.nr + p->num_objects,
1888                            in_pack.alloc);
1889
1890                 for (i = 0; i < p->num_objects; i++) {
1891                         sha1 = nth_packed_object_sha1(p, i);
1892                         o = lookup_unknown_object(sha1);
1893                         if (!(o->flags & OBJECT_ADDED))
1894                                 mark_in_pack_object(o, p, &in_pack);
1895                         o->flags |= OBJECT_ADDED;
1896                 }
1897         }
1898
1899         if (in_pack.nr) {
1900                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
1901                       ofscmp);
1902                 for (i = 0; i < in_pack.nr; i++) {
1903                         struct object *o = in_pack.array[i].object;
1904                         add_object_entry(o->sha1, o->type, "", 0);
1905                 }
1906         }
1907         free(in_pack.array);
1908 }
1909
1910 static void get_object_list(int ac, const char **av)
1911 {
1912         struct rev_info revs;
1913         char line[1000];
1914         int flags = 0;
1915
1916         init_revisions(&revs, NULL);
1917         save_commit_buffer = 0;
1918         track_object_refs = 0;
1919         setup_revisions(ac, av, &revs, NULL);
1920
1921         while (fgets(line, sizeof(line), stdin) != NULL) {
1922                 int len = strlen(line);
1923                 if (line[len - 1] == '\n')
1924                         line[--len] = 0;
1925                 if (!len)
1926                         break;
1927                 if (*line == '-') {
1928                         if (!strcmp(line, "--not")) {
1929                                 flags ^= UNINTERESTING;
1930                                 continue;
1931                         }
1932                         die("not a rev '%s'", line);
1933                 }
1934                 if (handle_revision_arg(line, &revs, flags, 1))
1935                         die("bad revision '%s'", line);
1936         }
1937
1938         prepare_revision_walk(&revs);
1939         mark_edges_uninteresting(revs.commits, &revs, show_edge);
1940         traverse_commit_list(&revs, show_commit, show_object);
1941
1942         if (keep_unreachable)
1943                 add_objects_in_unpacked_packs(&revs);
1944 }
1945
1946 static int adjust_perm(const char *path, mode_t mode)
1947 {
1948         if (chmod(path, mode))
1949                 return -1;
1950         return adjust_shared_perm(path);
1951 }
1952
1953 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
1954 {
1955         int use_internal_rev_list = 0;
1956         int thin = 0;
1957         uint32_t i;
1958         const char **rp_av;
1959         int rp_ac_alloc = 64;
1960         int rp_ac;
1961
1962         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
1963
1964         rp_av[0] = "pack-objects";
1965         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
1966         rp_ac = 2;
1967
1968         git_config(git_pack_config);
1969         if (!pack_compression_seen && core_compression_seen)
1970                 pack_compression_level = core_compression_level;
1971
1972         progress = isatty(2);
1973         for (i = 1; i < argc; i++) {
1974                 const char *arg = argv[i];
1975
1976                 if (*arg != '-')
1977                         break;
1978
1979                 if (!strcmp("--non-empty", arg)) {
1980                         non_empty = 1;
1981                         continue;
1982                 }
1983                 if (!strcmp("--local", arg)) {
1984                         local = 1;
1985                         continue;
1986                 }
1987                 if (!strcmp("--incremental", arg)) {
1988                         incremental = 1;
1989                         continue;
1990                 }
1991                 if (!prefixcmp(arg, "--compression=")) {
1992                         char *end;
1993                         int level = strtoul(arg+14, &end, 0);
1994                         if (!arg[14] || *end)
1995                                 usage(pack_usage);
1996                         if (level == -1)
1997                                 level = Z_DEFAULT_COMPRESSION;
1998                         else if (level < 0 || level > Z_BEST_COMPRESSION)
1999                                 die("bad pack compression level %d", level);
2000                         pack_compression_level = level;
2001                         continue;
2002                 }
2003                 if (!prefixcmp(arg, "--max-pack-size=")) {
2004                         char *end;
2005                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2006                         if (!arg[16] || *end)
2007                                 usage(pack_usage);
2008                         continue;
2009                 }
2010                 if (!prefixcmp(arg, "--window=")) {
2011                         char *end;
2012                         window = strtoul(arg+9, &end, 0);
2013                         if (!arg[9] || *end)
2014                                 usage(pack_usage);
2015                         continue;
2016                 }
2017                 if (!prefixcmp(arg, "--window-memory=")) {
2018                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2019                                 usage(pack_usage);
2020                         continue;
2021                 }
2022                 if (!prefixcmp(arg, "--threads=")) {
2023                         char *end;
2024                         delta_search_threads = strtoul(arg+10, &end, 0);
2025                         if (!arg[10] || *end || delta_search_threads < 1)
2026                                 usage(pack_usage);
2027 #ifndef THREADED_DELTA_SEARCH
2028                         if (delta_search_threads > 1)
2029                                 warning("no threads support, "
2030                                         "ignoring %s", arg);
2031 #endif
2032                         continue;
2033                 }
2034                 if (!prefixcmp(arg, "--depth=")) {
2035                         char *end;
2036                         depth = strtoul(arg+8, &end, 0);
2037                         if (!arg[8] || *end)
2038                                 usage(pack_usage);
2039                         continue;
2040                 }
2041                 if (!strcmp("--progress", arg)) {
2042                         progress = 1;
2043                         continue;
2044                 }
2045                 if (!strcmp("--all-progress", arg)) {
2046                         progress = 2;
2047                         continue;
2048                 }
2049                 if (!strcmp("-q", arg)) {
2050                         progress = 0;
2051                         continue;
2052                 }
2053                 if (!strcmp("--no-reuse-delta", arg)) {
2054                         no_reuse_delta = 1;
2055                         continue;
2056                 }
2057                 if (!strcmp("--no-reuse-object", arg)) {
2058                         no_reuse_object = no_reuse_delta = 1;
2059                         continue;
2060                 }
2061                 if (!strcmp("--delta-base-offset", arg)) {
2062                         allow_ofs_delta = 1;
2063                         continue;
2064                 }
2065                 if (!strcmp("--stdout", arg)) {
2066                         pack_to_stdout = 1;
2067                         continue;
2068                 }
2069                 if (!strcmp("--revs", arg)) {
2070                         use_internal_rev_list = 1;
2071                         continue;
2072                 }
2073                 if (!strcmp("--keep-unreachable", arg)) {
2074                         keep_unreachable = 1;
2075                         continue;
2076                 }
2077                 if (!strcmp("--unpacked", arg) ||
2078                     !prefixcmp(arg, "--unpacked=") ||
2079                     !strcmp("--reflog", arg) ||
2080                     !strcmp("--all", arg)) {
2081                         use_internal_rev_list = 1;
2082                         if (rp_ac >= rp_ac_alloc - 1) {
2083                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2084                                 rp_av = xrealloc(rp_av,
2085                                                  rp_ac_alloc * sizeof(*rp_av));
2086                         }
2087                         rp_av[rp_ac++] = arg;
2088                         continue;
2089                 }
2090                 if (!strcmp("--thin", arg)) {
2091                         use_internal_rev_list = 1;
2092                         thin = 1;
2093                         rp_av[1] = "--objects-edge";
2094                         continue;
2095                 }
2096                 if (!prefixcmp(arg, "--index-version=")) {
2097                         char *c;
2098                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2099                         if (pack_idx_default_version > 2)
2100                                 die("bad %s", arg);
2101                         if (*c == ',')
2102                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2103                         if (*c || pack_idx_off32_limit & 0x80000000)
2104                                 die("bad %s", arg);
2105                         continue;
2106                 }
2107                 usage(pack_usage);
2108         }
2109
2110         /* Traditionally "pack-objects [options] base extra" failed;
2111          * we would however want to take refs parameter that would
2112          * have been given to upstream rev-list ourselves, which means
2113          * we somehow want to say what the base name is.  So the
2114          * syntax would be:
2115          *
2116          * pack-objects [options] base <refs...>
2117          *
2118          * in other words, we would treat the first non-option as the
2119          * base_name and send everything else to the internal revision
2120          * walker.
2121          */
2122
2123         if (!pack_to_stdout)
2124                 base_name = argv[i++];
2125
2126         if (pack_to_stdout != !base_name)
2127                 usage(pack_usage);
2128
2129         if (pack_to_stdout && pack_size_limit)
2130                 die("--max-pack-size cannot be used to build a pack for transfer.");
2131
2132         if (!pack_to_stdout && thin)
2133                 die("--thin cannot be used to build an indexable pack.");
2134
2135         prepare_packed_git();
2136
2137         if (progress)
2138                 start_progress(&progress_state, "Counting objects", 0);
2139         if (!use_internal_rev_list)
2140                 read_object_list_from_stdin();
2141         else {
2142                 rp_av[rp_ac] = NULL;
2143                 get_object_list(rp_ac, rp_av);
2144         }
2145         if (progress)
2146                 stop_progress(&progress_state);
2147
2148         if (non_empty && !nr_result)
2149                 return 0;
2150         if (nr_result)
2151                 prepare_pack(window, depth);
2152         write_pack_file();
2153         if (progress)
2154                 fprintf(stderr, "Total %u (delta %u), reused %u (delta %u)\n",
2155                         written, written_delta, reused, reused_delta);
2156         return 0;
2157 }