pack-objects.c

   1 #include "cache.h"
   2 #include "object.h"
   3 #include "delta.h"
   4 #include "pack.h"
   5 #include "csum-file.h"
   6 #include <sys/time.h>
   7
   8 static const char pack_usage[] = "git-pack-objects [-q] [--non-empty] [--local] [--incremental] [--window=N] [--depth=N] {--stdout | base-name} < object-list";
   9
  10 struct object_entry {
  11         unsigned char sha1[20];
  12         unsigned long size;     /* uncompressed size */
  13         unsigned long offset;   /* offset into the final pack file (nonzero if already written) */
  14         unsigned int depth;     /* delta depth */
  15         unsigned int hash;      /* name hint hash */
  16         enum object_type type;
  17         unsigned long delta_size;       /* delta data size (uncompressed) */
  18         struct object_entry *delta;     /* delta base object */
  19         struct packed_git *in_pack;     /* already in pack */
  20         enum object_type in_pack_type;  /* could be delta */
  21         unsigned int in_pack_offset;
  22 };
  23
  24 /*
  25  * Objects we are going to pack are colected in objects array (dynamically
  26  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  27  * in the order we see -- typically rev-list --objects order that gives us
  28  * nice "minimum seek" order.
  29  *
  30  * sorted-by-sha ans sorted-by-type are arrays of pointers that point at
  31  * elements in the objects array.  The former is used to build the pack
  32  * index (lists object names in the ascending order to help offset lookup),
  33  * and the latter is used to group similar things together by try_delta()
  34  * heuristics.
  35  */
  36
  37 static unsigned char object_list_sha1[20];
  38 static int non_empty = 0;
  39 static int local = 0;
  40 static int incremental = 0;
  41 static struct object_entry **sorted_by_sha, **sorted_by_type;
  42 static struct object_entry *objects = NULL;
  43 static int nr_objects = 0, nr_alloc = 0;
  44 static const char *base_name;
  45 static unsigned char pack_file_sha1[20];
  46 static int progress = 1;
  47
  48 /*
  49  * The object names in objects array are hashed with this hashtable,
  50  * to help looking up the entry by object name.  Binary search from
  51  * sorted_by_sha is also possible but this was easier to code and faster.
  52  * This hashtable is built after all the objects are seen.
  53  */
  54 static int *object_ix = NULL;
  55 static int object_ix_hashsz = 0;
  56
  57 /*
  58  * Pack index for existing packs give us easy access to the offsets into
  59  * corresponding pack file where each object's data starts, but the entries
  60  * do not store the size of the compressed representation (uncompressed
  61  * size is easily available by examining the pack entry header).  We build
  62  * a hashtable of existing packs (pack_revindex), and keep reverse index
  63  * here -- pack index file is sorted by object name mapping to offset; this
  64  * pack_revindex[].revindex array is an ordered list of offsets, so if you
  65  * know the offset of an object, next offset is where its packed
  66  * representation ends.
  67  */
  68 struct pack_revindex {
  69         struct packed_git *p;
  70         unsigned long *revindex;
  71 } *pack_revindex = NULL;
  72 static int pack_revindex_hashsz = 0;
  73
  74 /*
  75  * stats
  76  */
  77 static int written = 0;
  78 static int reused = 0;
  79
  80 static int pack_revindex_ix(struct packed_git *p)
  81 {
  82         unsigned int ui = (unsigned int) p;
  83         int i;
  84
  85         ui = ui ^ (ui >> 16); /* defeat structure alignment */
  86         i = (int)(ui % pack_revindex_hashsz);
  87         while (pack_revindex[i].p) {
  88                 if (pack_revindex[i].p == p)
  89                         return i;
  90                 if (++i == pack_revindex_hashsz)
  91                         i = 0;
  92         }
  93         return -1 - i;
  94 }
  95
  96 static void prepare_pack_ix(void)
  97 {
  98         int num;
  99         struct packed_git *p;
 100         for (num = 0, p = packed_git; p; p = p->next)
 101                 num++;
 102         if (!num)
 103                 return;
 104         pack_revindex_hashsz = num * 11;
 105         pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
 106         for (p = packed_git; p; p = p->next) {
 107                 num = pack_revindex_ix(p);
 108                 num = - 1 - num;
 109                 pack_revindex[num].p = p;
 110         }
 111         /* revindex elements are lazily initialized */
 112 }
 113
 114 static int cmp_offset(const void *a_, const void *b_)
 115 {
 116         unsigned long a = *(unsigned long *) a_;
 117         unsigned long b = *(unsigned long *) b_;
 118         if (a < b)
 119                 return -1;
 120         else if (a == b)
 121                 return 0;
 122         else
 123                 return 1;
 124 }
 125
 126 /*
 127  * Ordered list of offsets of objects in the pack.
 128  */
 129 static void prepare_pack_revindex(struct pack_revindex *rix)
 130 {
 131         struct packed_git *p = rix->p;
 132         int num_ent = num_packed_objects(p);
 133         int i;
 134         void *index = p->index_base + 256;
 135
 136         rix->revindex = xmalloc(sizeof(unsigned long) * (num_ent + 1));
 137         for (i = 0; i < num_ent; i++) {
 138                 long hl = *((long *)(index + 24 * i));
 139                 rix->revindex[i] = ntohl(hl);
 140         }
 141         /* This knows the pack format -- the 20-byte trailer
 142          * follows immediately after the last object data.
 143          */
 144         rix->revindex[num_ent] = p->pack_size - 20;
 145         qsort(rix->revindex, num_ent, sizeof(unsigned long), cmp_offset);
 146 }
 147
 148 static unsigned long find_packed_object_size(struct packed_git *p,
 149                                              unsigned long ofs)
 150 {
 151         int num;
 152         int lo, hi;
 153         struct pack_revindex *rix;
 154         unsigned long *revindex;
 155         num = pack_revindex_ix(p);
 156         if (num < 0)
 157                 die("internal error: pack revindex uninitialized");
 158         rix = &pack_revindex[num];
 159         if (!rix->revindex)
 160                 prepare_pack_revindex(rix);
 161         revindex = rix->revindex;
 162         lo = 0;
 163         hi = num_packed_objects(p) + 1;
 164         do {
 165                 int mi = (lo + hi) / 2;
 166                 if (revindex[mi] == ofs) {
 167                         return revindex[mi+1] - ofs;
 168                 }
 169                 else if (ofs < revindex[mi])
 170                         hi = mi;
 171                 else
 172                         lo = mi + 1;
 173         } while (lo < hi);
 174         die("internal error: pack revindex corrupt");
 175 }
 176
 177 static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
 178 {
 179         unsigned long othersize, delta_size;
 180         char type[10];
 181         void *otherbuf = read_sha1_file(entry->delta->sha1, type, &othersize);
 182         void *delta_buf;
 183
 184         if (!otherbuf)
 185                 die("unable to read %s", sha1_to_hex(entry->delta->sha1));
 186         delta_buf = diff_delta(otherbuf, othersize,
 187                                buf, size, &delta_size, 0);
 188         if (!delta_buf || delta_size != entry->delta_size)
 189                 die("delta size changed");
 190         free(buf);
 191         free(otherbuf);
 192         return delta_buf;
 193 }
 194
 195 /*
 196  * The per-object header is a pretty dense thing, which is
 197  *  - first byte: low four bits are "size", then three bits of "type",
 198  *    and the high bit is "size continues".
 199  *  - each byte afterwards: low seven bits are size continuation,
 200  *    with the high bit being "size continues"
 201  */
 202 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 203 {
 204         int n = 1;
 205         unsigned char c;
 206
 207         if (type < OBJ_COMMIT || type > OBJ_DELTA)
 208                 die("bad type %d", type);
 209
 210         c = (type << 4) | (size & 15);
 211         size >>= 4;
 212         while (size) {
 213                 *hdr++ = c | 0x80;
 214                 c = size & 0x7f;
 215                 size >>= 7;
 216                 n++;
 217         }
 218         *hdr = c;
 219         return n;
 220 }
 221
 222 static unsigned long write_object(struct sha1file *f, struct object_entry *entry)
 223 {
 224         unsigned long size;
 225         char type[10];
 226         void *buf;
 227         unsigned char header[10];
 228         unsigned hdrlen, datalen;
 229         enum object_type obj_type;
 230
 231         obj_type = entry->type;
 232         if (!entry->in_pack ||
 233             (obj_type != entry->in_pack_type)) {
 234                 buf = read_sha1_file(entry->sha1, type, &size);
 235                 if (!buf)
 236                         die("unable to read %s", sha1_to_hex(entry->sha1));
 237                 if (size != entry->size)
 238                         die("object %s size inconsistency (%lu vs %lu)",
 239                             sha1_to_hex(entry->sha1), size, entry->size);
 240                 if (entry->delta) {
 241                         buf = delta_against(buf, size, entry);
 242                         size = entry->delta_size;
 243                         obj_type = OBJ_DELTA;
 244                 }
 245                 /*
 246                  * The object header is a byte of 'type' followed by zero or
 247                  * more bytes of length.  For deltas, the 20 bytes of delta
 248                  * sha1 follows that.
 249                  */
 250                 hdrlen = encode_header(obj_type, size, header);
 251                 sha1write(f, header, hdrlen);
 252
 253                 if (entry->delta) {
 254                         sha1write(f, entry->delta, 20);
 255                         hdrlen += 20;
 256                 }
 257                 datalen = sha1write_compressed(f, buf, size);
 258                 free(buf);
 259         }
 260         else {
 261                 struct packed_git *p = entry->in_pack;
 262                 use_packed_git(p);
 263
 264                 datalen = find_packed_object_size(p, entry->in_pack_offset);
 265                 buf = p->pack_base + entry->in_pack_offset;
 266                 sha1write(f, buf, datalen);
 267                 unuse_packed_git(p);
 268                 hdrlen = 0; /* not really */
 269                 reused++;
 270         }
 271         written++;
 272         return hdrlen + datalen;
 273 }
 274
 275 static unsigned long write_one(struct sha1file *f,
 276                                struct object_entry *e,
 277                                unsigned long offset)
 278 {
 279         if (e->offset)
 280                 /* offset starts from header size and cannot be zero
 281                  * if it is written already.
 282                  */
 283                 return offset;
 284         e->offset = offset;
 285         offset += write_object(f, e);
 286         /* if we are deltified, write out its base object. */
 287         if (e->delta)
 288                 offset = write_one(f, e->delta, offset);
 289         return offset;
 290 }
 291
 292 static void write_pack_file(void)
 293 {
 294         int i;
 295         struct sha1file *f;
 296         unsigned long offset;
 297         unsigned long mb;
 298         struct pack_header hdr;
 299
 300         if (!base_name)
 301                 f = sha1fd(1, "<stdout>");
 302         else
 303                 f = sha1create("%s-%s.%s", base_name, sha1_to_hex(object_list_sha1), "pack");
 304         hdr.hdr_signature = htonl(PACK_SIGNATURE);
 305         hdr.hdr_version = htonl(PACK_VERSION);
 306         hdr.hdr_entries = htonl(nr_objects);
 307         sha1write(f, &hdr, sizeof(hdr));
 308         offset = sizeof(hdr);
 309         for (i = 0; i < nr_objects; i++)
 310                 offset = write_one(f, objects + i, offset);
 311
 312         sha1close(f, pack_file_sha1, 1);
 313 }
 314
 315 static void write_index_file(void)
 316 {
 317         int i;
 318         struct sha1file *f = sha1create("%s-%s.%s", base_name, sha1_to_hex(object_list_sha1), "idx");
 319         struct object_entry **list = sorted_by_sha;
 320         struct object_entry **last = list + nr_objects;
 321         unsigned int array[256];
 322
 323         /*
 324          * Write the first-level table (the list is sorted,
 325          * but we use a 256-entry lookup to be able to avoid
 326          * having to do eight extra binary search iterations).
 327          */
 328         for (i = 0; i < 256; i++) {
 329                 struct object_entry **next = list;
 330                 while (next < last) {
 331                         struct object_entry *entry = *next;
 332                         if (entry->sha1[0] != i)
 333                                 break;
 334                         next++;
 335                 }
 336                 array[i] = htonl(next - sorted_by_sha);
 337                 list = next;
 338         }
 339         sha1write(f, array, 256 * sizeof(int));
 340
 341         /*
 342          * Write the actual SHA1 entries..
 343          */
 344         list = sorted_by_sha;
 345         for (i = 0; i < nr_objects; i++) {
 346                 struct object_entry *entry = *list++;
 347                 unsigned int offset = htonl(entry->offset);
 348                 sha1write(f, &offset, 4);
 349                 sha1write(f, entry->sha1, 20);
 350         }
 351         sha1write(f, pack_file_sha1, 20);
 352         sha1close(f, NULL, 1);
 353 }
 354
 355 static int add_object_entry(unsigned char *sha1, unsigned int hash)
 356 {
 357         unsigned int idx = nr_objects;
 358         struct object_entry *entry;
 359         struct packed_git *p;
 360         unsigned int found_offset;
 361         struct packed_git *found_pack;
 362
 363         found_pack = NULL;
 364         for (p = packed_git; p; p = p->next) {
 365                 struct pack_entry e;
 366                 if (find_pack_entry_one(sha1, &e, p)) {
 367                         if (incremental)
 368                                 return 0;
 369                         if (local && !p->pack_local)
 370                                 return 0;
 371                         if (!found_pack) {
 372                                 found_offset = e.offset;
 373                                 found_pack = e.p;
 374                         }
 375                 }
 376         }
 377
 378         if (idx >= nr_alloc) {
 379                 unsigned int needed = (idx + 1024) * 3 / 2;
 380                 objects = xrealloc(objects, needed * sizeof(*entry));
 381                 nr_alloc = needed;
 382         }
 383         entry = objects + idx;
 384         memset(entry, 0, sizeof(*entry));
 385         memcpy(entry->sha1, sha1, 20);
 386         entry->hash = hash;
 387         if (found_pack) {
 388                 entry->in_pack = found_pack;
 389                 entry->in_pack_offset = found_offset;
 390         }
 391         nr_objects = idx+1;
 392         return 1;
 393 }
 394
 395 static int locate_object_entry_hash(unsigned char *sha1)
 396 {
 397         int i;
 398         unsigned int ui;
 399         memcpy(&ui, sha1, sizeof(unsigned int));
 400         i = ui % object_ix_hashsz;
 401         while (0 < object_ix[i]) {
 402                 if (!memcmp(sha1, objects[object_ix[i]-1].sha1, 20))
 403                         return i;
 404                 if (++i == object_ix_hashsz)
 405                         i = 0;
 406         }
 407         return -1 - i;
 408 }
 409
 410 static struct object_entry *locate_object_entry(unsigned char *sha1)
 411 {
 412         int i = locate_object_entry_hash(sha1);
 413         if (0 <= i)
 414                 return &objects[object_ix[i]-1];
 415         return NULL;
 416 }
 417
 418 static void check_object(struct object_entry *entry)
 419 {
 420         char type[20];
 421
 422         if (entry->in_pack) {
 423                 /* Check if it is delta, and the base is also an object
 424                  * we are going to pack.  If so we will reuse the existing
 425                  * delta.
 426                  */
 427                 unsigned char base[20];
 428                 unsigned long size;
 429                 struct object_entry *base_entry;
 430                 if (!check_reuse_pack_delta(entry->in_pack,
 431                                             entry->in_pack_offset,
 432                                             base, &size,
 433                                             &entry->in_pack_type) &&
 434                     (base_entry = locate_object_entry(base))) {
 435                         /* We do not know depth at this point, but it
 436                          * does not matter.  Getting delta_chain_length
 437                          * with packed_object_info_detail() is not so
 438                          * expensive, so we could do that later if we
 439                          * wanted to.  Calling sha1_object_info to get
 440                          * the true size (and later an uncompressed
 441                          * representation) of deeply deltified object
 442                          * is quite expensive.
 443                          */
 444                         entry->depth = 1;
 445                         /* uncompressed size */
 446                         entry->size = entry->delta_size = size;
 447                         entry->delta = base_entry;
 448                         entry->type = OBJ_DELTA;
 449                         return;
 450                 }
 451                 /* Otherwise we would do the usual */
 452         }
 453
 454         if (sha1_object_info(entry->sha1, type, &entry->size))
 455                 die("unable to get type of object %s",
 456                     sha1_to_hex(entry->sha1));
 457
 458         if (!strcmp(type, "commit")) {
 459                 entry->type = OBJ_COMMIT;
 460         } else if (!strcmp(type, "tree")) {
 461                 entry->type = OBJ_TREE;
 462         } else if (!strcmp(type, "blob")) {
 463                 entry->type = OBJ_BLOB;
 464         } else if (!strcmp(type, "tag")) {
 465                 entry->type = OBJ_TAG;
 466         } else
 467                 die("unable to pack object %s of type %s",
 468                     sha1_to_hex(entry->sha1), type);
 469 }
 470
 471 static void hash_objects(void)
 472 {
 473         int i;
 474         struct object_entry *oe;
 475
 476         object_ix_hashsz = nr_objects * 2;
 477         object_ix = xcalloc(sizeof(int), object_ix_hashsz);
 478         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 479                 int ix = locate_object_entry_hash(oe->sha1);
 480                 if (0 <= ix) {
 481                         error("the same object '%s' added twice",
 482                               sha1_to_hex(oe->sha1));
 483                         continue;
 484                 }
 485                 ix = -1 - ix;
 486                 object_ix[ix] = i + 1;
 487         }
 488 }
 489
 490 static void get_object_details(void)
 491 {
 492         int i;
 493         struct object_entry *entry = objects;
 494
 495         hash_objects();
 496         prepare_pack_ix();
 497         for (i = 0; i < nr_objects; i++)
 498                 check_object(entry++);
 499 }
 500
 501 typedef int (*entry_sort_t)(const struct object_entry *, const struct object_entry *);
 502
 503 static entry_sort_t current_sort;
 504
 505 static int sort_comparator(const void *_a, const void *_b)
 506 {
 507         struct object_entry *a = *(struct object_entry **)_a;
 508         struct object_entry *b = *(struct object_entry **)_b;
 509         return current_sort(a,b);
 510 }
 511
 512 static struct object_entry **create_sorted_list(entry_sort_t sort)
 513 {
 514         struct object_entry **list = xmalloc(nr_objects * sizeof(struct object_entry *));
 515         int i;
 516
 517         for (i = 0; i < nr_objects; i++)
 518                 list[i] = objects + i;
 519         current_sort = sort;
 520         qsort(list, nr_objects, sizeof(struct object_entry *), sort_comparator);
 521         return list;
 522 }
 523
 524 static int sha1_sort(const struct object_entry *a, const struct object_entry *b)
 525 {
 526         return memcmp(a->sha1, b->sha1, 20);
 527 }
 528
 529 static int type_size_sort(const struct object_entry *a, const struct object_entry *b)
 530 {
 531         if (a->type < b->type)
 532                 return -1;
 533         if (a->type > b->type)
 534                 return 1;
 535         if (a->hash < b->hash)
 536                 return -1;
 537         if (a->hash > b->hash)
 538                 return 1;
 539         if (a->size < b->size)
 540                 return -1;
 541         if (a->size > b->size)
 542                 return 1;
 543         return a < b ? -1 : (a > b);
 544 }
 545
 546 struct unpacked {
 547         struct object_entry *entry;
 548         void *data;
 549 };
 550
 551 /*
 552  * We search for deltas _backwards_ in a list sorted by type and
 553  * by size, so that we see progressively smaller and smaller files.
 554  * That's because we prefer deltas to be from the bigger file
 555  * to the smaller - deletes are potentially cheaper, but perhaps
 556  * more importantly, the bigger file is likely the more recent
 557  * one.
 558  */
 559 static int try_delta(struct unpacked *cur, struct unpacked *old, unsigned max_depth)
 560 {
 561         struct object_entry *cur_entry = cur->entry;
 562         struct object_entry *old_entry = old->entry;
 563         unsigned long size, oldsize, delta_size, sizediff;
 564         long max_size;
 565         void *delta_buf;
 566
 567         /* Don't bother doing diffs between different types */
 568         if (cur_entry->type != old_entry->type)
 569                 return -1;
 570
 571         size = cur_entry->size;
 572         if (size < 50)
 573                 return -1;
 574         oldsize = old_entry->size;
 575         sizediff = oldsize > size ? oldsize - size : size - oldsize;
 576         if (sizediff > size / 8)
 577                 return -1;
 578         if (old_entry->depth >= max_depth)
 579                 return 0;
 580
 581         /*
 582          * NOTE!
 583          *
 584          * We always delta from the bigger to the smaller, since that's
 585          * more space-efficient (deletes don't have to say _what_ they
 586          * delete).
 587          */
 588         max_size = size / 2 - 20;
 589         if (cur_entry->delta)
 590                 max_size = cur_entry->delta_size-1;
 591         if (sizediff >= max_size)
 592                 return -1;
 593         delta_buf = diff_delta(old->data, oldsize,
 594                                cur->data, size, &delta_size, max_size);
 595         if (!delta_buf)
 596                 return 0;
 597         cur_entry->delta = old_entry;
 598         cur_entry->delta_size = delta_size;
 599         cur_entry->depth = old_entry->depth + 1;
 600         free(delta_buf);
 601         return 0;
 602 }
 603
 604 static void find_deltas(struct object_entry **list, int window, int depth)
 605 {
 606         int i, idx;
 607         unsigned int array_size = window * sizeof(struct unpacked);
 608         struct unpacked *array = xmalloc(array_size);
 609         int eye_candy;
 610
 611         memset(array, 0, array_size);
 612         i = nr_objects;
 613         idx = 0;
 614         eye_candy = i - (nr_objects / 20);
 615
 616         while (--i >= 0) {
 617                 struct object_entry *entry = list[i];
 618                 struct unpacked *n = array + idx;
 619                 unsigned long size;
 620                 char type[10];
 621                 int j;
 622
 623                 if (progress && i <= eye_candy) {
 624                         eye_candy -= nr_objects / 20;
 625                         fputc('.', stderr);
 626                 }
 627
 628                 if (entry->delta)
 629                         /* This happens if we decided to reuse existing
 630                          * delta from a pack.
 631                          */
 632                         continue;
 633
 634                 free(n->data);
 635                 n->entry = entry;
 636                 n->data = read_sha1_file(entry->sha1, type, &size);
 637                 if (size != entry->size)
 638                         die("object %s inconsistent object length (%lu vs %lu)", sha1_to_hex(entry->sha1), size, entry->size);
 639                 j = window;
 640                 while (--j > 0) {
 641                         unsigned int other_idx = idx + j;
 642                         struct unpacked *m;
 643                         if (other_idx >= window)
 644                                 other_idx -= window;
 645                         m = array + other_idx;
 646                         if (!m->entry)
 647                                 break;
 648                         if (try_delta(n, m, depth) < 0)
 649                                 break;
 650                 }
 651                 idx++;
 652                 if (idx >= window)
 653                         idx = 0;
 654         }
 655
 656         for (i = 0; i < window; ++i)
 657                 free(array[i].data);
 658         free(array);
 659 }
 660
 661 static void prepare_pack(int window, int depth)
 662 {
 663         if (progress)
 664                 fprintf(stderr, "Packing %d objects", nr_objects);
 665         get_object_details();
 666         if (progress)
 667                 fprintf(stderr, ".");
 668
 669         sorted_by_type = create_sorted_list(type_size_sort);
 670         if (window && depth)
 671                 find_deltas(sorted_by_type, window+1, depth);
 672         if (progress)
 673                 fputc('\n', stderr);
 674         write_pack_file();
 675 }
 676
 677 static int reuse_cached_pack(unsigned char *sha1, int pack_to_stdout)
 678 {
 679         static const char cache[] = "pack-cache/pack-%s.%s";
 680         char *cached_pack, *cached_idx;
 681         int ifd, ofd, ifd_ix = -1;
 682
 683         cached_pack = git_path(cache, sha1_to_hex(sha1), "pack");
 684         ifd = open(cached_pack, O_RDONLY);
 685         if (ifd < 0)
 686                 return 0;
 687
 688         if (!pack_to_stdout) {
 689                 cached_idx = git_path(cache, sha1_to_hex(sha1), "idx");
 690                 ifd_ix = open(cached_idx, O_RDONLY);
 691                 if (ifd_ix < 0) {
 692                         close(ifd);
 693                         return 0;
 694                 }
 695         }
 696
 697         fprintf(stderr, "Reusing %d objects pack %s\n", nr_objects,
 698                 sha1_to_hex(sha1));
 699
 700         if (pack_to_stdout) {
 701                 if (copy_fd(ifd, 1))
 702                         exit(1);
 703                 close(ifd);
 704         }
 705         else {
 706                 char name[PATH_MAX];
 707                 snprintf(name, sizeof(name),
 708                          "%s-%s.%s", base_name, sha1_to_hex(sha1), "pack");
 709                 ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
 710                 if (ofd < 0)
 711                         die("unable to open %s (%s)", name, strerror(errno));
 712                 if (copy_fd(ifd, ofd))
 713                         exit(1);
 714                 close(ifd);
 715
 716                 snprintf(name, sizeof(name),
 717                          "%s-%s.%s", base_name, sha1_to_hex(sha1), "idx");
 718                 ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
 719                 if (ofd < 0)
 720                         die("unable to open %s (%s)", name, strerror(errno));
 721                 if (copy_fd(ifd_ix, ofd))
 722                         exit(1);
 723                 close(ifd_ix);
 724                 puts(sha1_to_hex(sha1));
 725         }
 726
 727         return 1;
 728 }
 729
 730 int main(int argc, char **argv)
 731 {
 732         SHA_CTX ctx;
 733         char line[PATH_MAX + 20];
 734         int window = 10, depth = 10, pack_to_stdout = 0;
 735         struct object_entry **list;
 736         int i;
 737         struct timeval prev_tv;
 738         int eye_candy = 0;
 739         int eye_candy_incr = 500;
 740
 741
 742         setup_git_directory();
 743
 744         for (i = 1; i < argc; i++) {
 745                 const char *arg = argv[i];
 746
 747                 if (*arg == '-') {
 748                         if (!strcmp("--non-empty", arg)) {
 749                                 non_empty = 1;
 750                                 continue;
 751                         }
 752                         if (!strcmp("--local", arg)) {
 753                                 local = 1;
 754                                 continue;
 755                         }
 756                         if (!strcmp("--incremental", arg)) {
 757                                 incremental = 1;
 758                                 continue;
 759                         }
 760                         if (!strncmp("--window=", arg, 9)) {
 761                                 char *end;
 762                                 window = strtoul(arg+9, &end, 0);
 763                                 if (!arg[9] || *end)
 764                                         usage(pack_usage);
 765                                 continue;
 766                         }
 767                         if (!strncmp("--depth=", arg, 8)) {
 768                                 char *end;
 769                                 depth = strtoul(arg+8, &end, 0);
 770                                 if (!arg[8] || *end)
 771                                         usage(pack_usage);
 772                                 continue;
 773                         }
 774                         if (!strcmp("-q", arg)) {
 775                                 progress = 0;
 776                                 continue;
 777                         }
 778                         if (!strcmp("--stdout", arg)) {
 779                                 pack_to_stdout = 1;
 780                                 continue;
 781                         }
 782                         usage(pack_usage);
 783                 }
 784                 if (base_name)
 785                         usage(pack_usage);
 786                 base_name = arg;
 787         }
 788
 789         if (pack_to_stdout != !base_name)
 790                 usage(pack_usage);
 791
 792         prepare_packed_git();
 793         if (progress) {
 794                 fprintf(stderr, "Generating pack...\n");
 795                 gettimeofday(&prev_tv, NULL);
 796         }
 797         while (fgets(line, sizeof(line), stdin) != NULL) {
 798                 unsigned int hash;
 799                 char *p;
 800                 unsigned char sha1[20];
 801
 802                 if (progress && (eye_candy <= nr_objects)) {
 803                         fprintf(stderr, "Counting objects...%d\r", nr_objects);
 804                         if (eye_candy && (50 <= eye_candy_incr)) {
 805                                 struct timeval tv;
 806                                 int time_diff;
 807                                 gettimeofday(&tv, NULL);
 808                                 time_diff = (tv.tv_sec - prev_tv.tv_sec);
 809                                 time_diff <<= 10;
 810                                 time_diff += (tv.tv_usec - prev_tv.tv_usec);
 811                                 if ((1 << 9) < time_diff)
 812                                         eye_candy_incr += 50;
 813                                 else if (50 < eye_candy_incr)
 814                                         eye_candy_incr -= 50;
 815                         }
 816                         eye_candy += eye_candy_incr;
 817                 }
 818                 if (get_sha1_hex(line, sha1))
 819                         die("expected sha1, got garbage:\n %s", line);
 820                 hash = 0;
 821                 p = line+40;
 822                 while (*p) {
 823                         unsigned char c = *p++;
 824                         if (isspace(c))
 825                                 continue;
 826                         hash = hash * 11 + c;
 827                 }
 828                 add_object_entry(sha1, hash);
 829         }
 830         if (progress)
 831                 fprintf(stderr, "Done counting %d objects.\n", nr_objects);
 832         if (non_empty && !nr_objects)
 833                 return 0;
 834
 835         sorted_by_sha = create_sorted_list(sha1_sort);
 836         SHA1_Init(&ctx);
 837         list = sorted_by_sha;
 838         for (i = 0; i < nr_objects; i++) {
 839                 struct object_entry *entry = *list++;
 840                 SHA1_Update(&ctx, entry->sha1, 20);
 841         }
 842         SHA1_Final(object_list_sha1, &ctx);
 843
 844         if (reuse_cached_pack(object_list_sha1, pack_to_stdout))
 845                 ;
 846         else {
 847                 prepare_pack(window, depth);
 848                 if (!pack_to_stdout) {
 849                         write_index_file();
 850                         puts(sha1_to_hex(object_list_sha1));
 851                 }
 852         }
 853         fprintf(stderr, "Total %d, written %d, reused %d\n",
 854                 nr_objects, written, reused);
 855         return 0;
 856 }