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

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "object.h"
   4 #include "blob.h"
   5 #include "commit.h"
   6 #include "tag.h"
   7 #include "tree.h"
   8 #include "delta.h"
   9 #include "pack.h"
  10 #include "csum-file.h"
  11 #include "tree-walk.h"
  12 #include <sys/time.h>
  13 #include <signal.h>
  14
  15 static const char pack_usage[] = "git-pack-objects [-q] [--no-reuse-delta] [--non-empty] [--local] [--incremental] [--window=N] [--depth=N] {--stdout | base-name} < object-list";
  16
  17 struct object_entry {
  18         unsigned char sha1[20];
  19         unsigned long size;     /* uncompressed size */
  20         unsigned long offset;   /* offset into the final pack file;
  21                                  * nonzero if already written.
  22                                  */
  23         unsigned int depth;     /* delta depth */
  24         unsigned int delta_limit;       /* base adjustment for in-pack delta */
  25         unsigned int hash;      /* name hint hash */
  26         enum object_type type;
  27         enum object_type in_pack_type;  /* could be delta */
  28         unsigned long delta_size;       /* delta data size (uncompressed) */
  29         struct object_entry *delta;     /* delta base object */
  30         struct packed_git *in_pack;     /* already in pack */
  31         unsigned int in_pack_offset;
  32         struct object_entry *delta_child; /* deltified objects who bases me */
  33         struct object_entry *delta_sibling; /* other deltified objects who
  34                                              * uses the same base as me
  35                                              */
  36         int preferred_base;     /* we do not pack this, but is encouraged to
  37                                  * be used as the base objectto delta huge
  38                                  * objects against.
  39                                  */
  40 };
  41
  42 /*
  43  * Objects we are going to pack are collected in objects array (dynamically
  44  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  45  * in the order we see -- typically rev-list --objects order that gives us
  46  * nice "minimum seek" order.
  47  *
  48  * sorted-by-sha ans sorted-by-type are arrays of pointers that point at
  49  * elements in the objects array.  The former is used to build the pack
  50  * index (lists object names in the ascending order to help offset lookup),
  51  * and the latter is used to group similar things together by try_delta()
  52  * heuristics.
  53  */
  54
  55 static unsigned char object_list_sha1[20];
  56 static int non_empty;
  57 static int no_reuse_delta;
  58 static int local;
  59 static int incremental;
  60 static struct object_entry **sorted_by_sha, **sorted_by_type;
  61 static struct object_entry *objects;
  62 static int nr_objects, nr_alloc, nr_result;
  63 static const char *base_name;
  64 static unsigned char pack_file_sha1[20];
  65 static int progress = 1;
  66 static volatile sig_atomic_t progress_update;
  67 static int window = 10;
  68 static int pack_to_stdout;
  69
  70 /*
  71  * The object names in objects array are hashed with this hashtable,
  72  * to help looking up the entry by object name.  Binary search from
  73  * sorted_by_sha is also possible but this was easier to code and faster.
  74  * This hashtable is built after all the objects are seen.
  75  */
  76 static int *object_ix;
  77 static int object_ix_hashsz;
  78
  79 /*
  80  * Pack index for existing packs give us easy access to the offsets into
  81  * corresponding pack file where each object's data starts, but the entries
  82  * do not store the size of the compressed representation (uncompressed
  83  * size is easily available by examining the pack entry header).  We build
  84  * a hashtable of existing packs (pack_revindex), and keep reverse index
  85  * here -- pack index file is sorted by object name mapping to offset; this
  86  * pack_revindex[].revindex array is an ordered list of offsets, so if you
  87  * know the offset of an object, next offset is where its packed
  88  * representation ends.
  89  */
  90 struct pack_revindex {
  91         struct packed_git *p;
  92         unsigned long *revindex;
  93 } *pack_revindex = NULL;
  94 static int pack_revindex_hashsz;
  95
  96 /*
  97  * stats
  98  */
  99 static int written;
 100 static int written_delta;
 101 static int reused;
 102 static int reused_delta;
 103
 104 static int pack_revindex_ix(struct packed_git *p)
 105 {
 106         unsigned long ui = (unsigned long)p;
 107         int i;
 108
 109         ui = ui ^ (ui >> 16); /* defeat structure alignment */
 110         i = (int)(ui % pack_revindex_hashsz);
 111         while (pack_revindex[i].p) {
 112                 if (pack_revindex[i].p == p)
 113                         return i;
 114                 if (++i == pack_revindex_hashsz)
 115                         i = 0;
 116         }
 117         return -1 - i;
 118 }
 119
 120 static void prepare_pack_ix(void)
 121 {
 122         int num;
 123         struct packed_git *p;
 124         for (num = 0, p = packed_git; p; p = p->next)
 125                 num++;
 126         if (!num)
 127                 return;
 128         pack_revindex_hashsz = num * 11;
 129         pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
 130         for (p = packed_git; p; p = p->next) {
 131                 num = pack_revindex_ix(p);
 132                 num = - 1 - num;
 133                 pack_revindex[num].p = p;
 134         }
 135         /* revindex elements are lazily initialized */
 136 }
 137
 138 static int cmp_offset(const void *a_, const void *b_)
 139 {
 140         unsigned long a = *(unsigned long *) a_;
 141         unsigned long b = *(unsigned long *) b_;
 142         if (a < b)
 143                 return -1;
 144         else if (a == b)
 145                 return 0;
 146         else
 147                 return 1;
 148 }
 149
 150 /*
 151  * Ordered list of offsets of objects in the pack.
 152  */
 153 static void prepare_pack_revindex(struct pack_revindex *rix)
 154 {
 155         struct packed_git *p = rix->p;
 156         int num_ent = num_packed_objects(p);
 157         int i;
 158         void *index = p->index_base + 256;
 159
 160         rix->revindex = xmalloc(sizeof(unsigned long) * (num_ent + 1));
 161         for (i = 0; i < num_ent; i++) {
 162                 unsigned int hl = *((unsigned int *)((char *) index + 24*i));
 163                 rix->revindex[i] = ntohl(hl);
 164         }
 165         /* This knows the pack format -- the 20-byte trailer
 166          * follows immediately after the last object data.
 167          */
 168         rix->revindex[num_ent] = p->pack_size - 20;
 169         qsort(rix->revindex, num_ent, sizeof(unsigned long), cmp_offset);
 170 }
 171
 172 static unsigned long find_packed_object_size(struct packed_git *p,
 173                                              unsigned long ofs)
 174 {
 175         int num;
 176         int lo, hi;
 177         struct pack_revindex *rix;
 178         unsigned long *revindex;
 179         num = pack_revindex_ix(p);
 180         if (num < 0)
 181                 die("internal error: pack revindex uninitialized");
 182         rix = &pack_revindex[num];
 183         if (!rix->revindex)
 184                 prepare_pack_revindex(rix);
 185         revindex = rix->revindex;
 186         lo = 0;
 187         hi = num_packed_objects(p) + 1;
 188         do {
 189                 int mi = (lo + hi) / 2;
 190                 if (revindex[mi] == ofs) {
 191                         return revindex[mi+1] - ofs;
 192                 }
 193                 else if (ofs < revindex[mi])
 194                         hi = mi;
 195                 else
 196                         lo = mi + 1;
 197         } while (lo < hi);
 198         die("internal error: pack revindex corrupt");
 199 }
 200
 201 static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
 202 {
 203         unsigned long othersize, delta_size;
 204         char type[10];
 205         void *otherbuf = read_sha1_file(entry->delta->sha1, type, &othersize);
 206         void *delta_buf;
 207
 208         if (!otherbuf)
 209                 die("unable to read %s", sha1_to_hex(entry->delta->sha1));
 210         delta_buf = diff_delta(otherbuf, othersize,
 211                                buf, size, &delta_size, 0);
 212         if (!delta_buf || delta_size != entry->delta_size)
 213                 die("delta size changed");
 214         free(buf);
 215         free(otherbuf);
 216         return delta_buf;
 217 }
 218
 219 /*
 220  * The per-object header is a pretty dense thing, which is
 221  *  - first byte: low four bits are "size", then three bits of "type",
 222  *    and the high bit is "size continues".
 223  *  - each byte afterwards: low seven bits are size continuation,
 224  *    with the high bit being "size continues"
 225  */
 226 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 227 {
 228         int n = 1;
 229         unsigned char c;
 230
 231         if (type < OBJ_COMMIT || type > OBJ_DELTA)
 232                 die("bad type %d", type);
 233
 234         c = (type << 4) | (size & 15);
 235         size >>= 4;
 236         while (size) {
 237                 *hdr++ = c | 0x80;
 238                 c = size & 0x7f;
 239                 size >>= 7;
 240                 n++;
 241         }
 242         *hdr = c;
 243         return n;
 244 }
 245
 246 static int revalidate_one(struct object_entry *entry,
 247                           void *data, char *type, unsigned long size)
 248 {
 249         int err;
 250         if ((!data) ||
 251             ((entry->type != OBJ_DELTA) &&
 252              ( (size != entry->size) ||
 253                strcmp(type_names[entry->type], type))))
 254                 err = -1;
 255         else
 256                 err = check_sha1_signature(entry->sha1, data, size, type);
 257         free(data);
 258         return err;
 259 }
 260
 261 /*
 262  * we are going to reuse the existing pack entry data.  make
 263  * sure it is not corrupt.
 264  */
 265 static int revalidate_pack_entry(struct object_entry *entry)
 266 {
 267         void *data;
 268         char type[20];
 269         unsigned long size;
 270         struct pack_entry e;
 271
 272         if (pack_to_stdout)
 273                 return 0;
 274
 275         e.p = entry->in_pack;
 276         e.offset = entry->in_pack_offset;
 277
 278         /* the caller has already called use_packed_git() for us */
 279         data = unpack_entry_gently(&e, type, &size);
 280         return revalidate_one(entry, data, type, size);
 281 }
 282
 283 static int revalidate_loose_object(struct object_entry *entry,
 284                                    unsigned char *map,
 285                                    unsigned long mapsize)
 286 {
 287         /* we already know this is a loose object with new type header. */
 288         void *data;
 289         char type[20];
 290         unsigned long size;
 291
 292         if (pack_to_stdout)
 293                 return 0;
 294
 295         data = unpack_sha1_file(map, mapsize, type, &size);
 296         return revalidate_one(entry, data, type, size);
 297 }
 298
 299 static unsigned long write_object(struct sha1file *f,
 300                                   struct object_entry *entry)
 301 {
 302         unsigned long size;
 303         char type[10];
 304         void *buf;
 305         unsigned char header[10];
 306         unsigned hdrlen, datalen;
 307         enum object_type obj_type;
 308         int to_reuse = 0;
 309
 310         if (entry->preferred_base)
 311                 return 0;
 312
 313         obj_type = entry->type;
 314         if (! entry->in_pack)
 315                 to_reuse = 0;   /* can't reuse what we don't have */
 316         else if (obj_type == OBJ_DELTA)
 317                 to_reuse = 1;   /* check_object() decided it for us */
 318         else if (obj_type != entry->in_pack_type)
 319                 to_reuse = 0;   /* pack has delta which is unusable */
 320         else if (entry->delta)
 321                 to_reuse = 0;   /* we want to pack afresh */
 322         else
 323                 to_reuse = 1;   /* we have it in-pack undeltified,
 324                                  * and we do not need to deltify it.
 325                                  */
 326
 327         if (!entry->in_pack && !entry->delta) {
 328                 unsigned char *map;
 329                 unsigned long mapsize;
 330                 map = map_sha1_file(entry->sha1, &mapsize);
 331                 if (map && !legacy_loose_object(map)) {
 332                         /* We can copy straight into the pack file */
 333                         if (revalidate_loose_object(entry, map, mapsize))
 334                                 die("corrupt loose object %s",
 335                                     sha1_to_hex(entry->sha1));
 336                         sha1write(f, map, mapsize);
 337                         munmap(map, mapsize);
 338                         written++;
 339                         reused++;
 340                         return mapsize;
 341                 }
 342                 if (map)
 343                         munmap(map, mapsize);
 344         }
 345
 346         if (!to_reuse) {
 347                 buf = read_sha1_file(entry->sha1, type, &size);
 348                 if (!buf)
 349                         die("unable to read %s", sha1_to_hex(entry->sha1));
 350                 if (size != entry->size)
 351                         die("object %s size inconsistency (%lu vs %lu)",
 352                             sha1_to_hex(entry->sha1), size, entry->size);
 353                 if (entry->delta) {
 354                         buf = delta_against(buf, size, entry);
 355                         size = entry->delta_size;
 356                         obj_type = OBJ_DELTA;
 357                 }
 358                 /*
 359                  * The object header is a byte of 'type' followed by zero or
 360                  * more bytes of length.  For deltas, the 20 bytes of delta
 361                  * sha1 follows that.
 362                  */
 363                 hdrlen = encode_header(obj_type, size, header);
 364                 sha1write(f, header, hdrlen);
 365
 366                 if (entry->delta) {
 367                         sha1write(f, entry->delta, 20);
 368                         hdrlen += 20;
 369                 }
 370                 datalen = sha1write_compressed(f, buf, size);
 371                 free(buf);
 372         }
 373         else {
 374                 struct packed_git *p = entry->in_pack;
 375                 use_packed_git(p);
 376
 377                 datalen = find_packed_object_size(p, entry->in_pack_offset);
 378                 buf = (char *) p->pack_base + entry->in_pack_offset;
 379
 380                 if (revalidate_pack_entry(entry))
 381                         die("corrupt delta in pack %s", sha1_to_hex(entry->sha1));
 382                 sha1write(f, buf, datalen);
 383                 unuse_packed_git(p);
 384                 hdrlen = 0; /* not really */
 385                 if (obj_type == OBJ_DELTA)
 386                         reused_delta++;
 387                 reused++;
 388         }
 389         if (obj_type == OBJ_DELTA)
 390                 written_delta++;
 391         written++;
 392         return hdrlen + datalen;
 393 }
 394
 395 static unsigned long write_one(struct sha1file *f,
 396                                struct object_entry *e,
 397                                unsigned long offset)
 398 {
 399         if (e->offset)
 400                 /* offset starts from header size and cannot be zero
 401                  * if it is written already.
 402                  */
 403                 return offset;
 404         e->offset = offset;
 405         offset += write_object(f, e);
 406         /* if we are deltified, write out its base object. */
 407         if (e->delta)
 408                 offset = write_one(f, e->delta, offset);
 409         return offset;
 410 }
 411
 412 static void write_pack_file(void)
 413 {
 414         int i;
 415         struct sha1file *f;
 416         unsigned long offset;
 417         struct pack_header hdr;
 418         unsigned last_percent = 999;
 419         int do_progress = 0;
 420
 421         if (!base_name)
 422                 f = sha1fd(1, "<stdout>");
 423         else {
 424                 f = sha1create("%s-%s.%s", base_name,
 425                                sha1_to_hex(object_list_sha1), "pack");
 426                 do_progress = progress;
 427         }
 428         if (do_progress)
 429                 fprintf(stderr, "Writing %d objects.\n", nr_result);
 430
 431         hdr.hdr_signature = htonl(PACK_SIGNATURE);
 432         hdr.hdr_version = htonl(PACK_VERSION);
 433         hdr.hdr_entries = htonl(nr_result);
 434         sha1write(f, &hdr, sizeof(hdr));
 435         offset = sizeof(hdr);
 436         if (!nr_result)
 437                 goto done;
 438         for (i = 0; i < nr_objects; i++) {
 439                 offset = write_one(f, objects + i, offset);
 440                 if (do_progress) {
 441                         unsigned percent = written * 100 / nr_result;
 442                         if (progress_update || percent != last_percent) {
 443                                 fprintf(stderr, "%4u%% (%u/%u) done\r",
 444                                         percent, written, nr_result);
 445                                 progress_update = 0;
 446                                 last_percent = percent;
 447                         }
 448                 }
 449         }
 450         if (do_progress)
 451                 fputc('\n', stderr);
 452  done:
 453         sha1close(f, pack_file_sha1, 1);
 454 }
 455
 456 static void write_index_file(void)
 457 {
 458         int i;
 459         struct sha1file *f = sha1create("%s-%s.%s", base_name,
 460                                         sha1_to_hex(object_list_sha1), "idx");
 461         struct object_entry **list = sorted_by_sha;
 462         struct object_entry **last = list + nr_result;
 463         unsigned int array[256];
 464
 465         /*
 466          * Write the first-level table (the list is sorted,
 467          * but we use a 256-entry lookup to be able to avoid
 468          * having to do eight extra binary search iterations).
 469          */
 470         for (i = 0; i < 256; i++) {
 471                 struct object_entry **next = list;
 472                 while (next < last) {
 473                         struct object_entry *entry = *next;
 474                         if (entry->sha1[0] != i)
 475                                 break;
 476                         next++;
 477                 }
 478                 array[i] = htonl(next - sorted_by_sha);
 479                 list = next;
 480         }
 481         sha1write(f, array, 256 * sizeof(int));
 482
 483         /*
 484          * Write the actual SHA1 entries..
 485          */
 486         list = sorted_by_sha;
 487         for (i = 0; i < nr_result; i++) {
 488                 struct object_entry *entry = *list++;
 489                 unsigned int offset = htonl(entry->offset);
 490                 sha1write(f, &offset, 4);
 491                 sha1write(f, entry->sha1, 20);
 492         }
 493         sha1write(f, pack_file_sha1, 20);
 494         sha1close(f, NULL, 1);
 495 }
 496
 497 static int locate_object_entry_hash(const unsigned char *sha1)
 498 {
 499         int i;
 500         unsigned int ui;
 501         memcpy(&ui, sha1, sizeof(unsigned int));
 502         i = ui % object_ix_hashsz;
 503         while (0 < object_ix[i]) {
 504                 if (!hashcmp(sha1, objects[object_ix[i] - 1].sha1))
 505                         return i;
 506                 if (++i == object_ix_hashsz)
 507                         i = 0;
 508         }
 509         return -1 - i;
 510 }
 511
 512 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 513 {
 514         int i;
 515
 516         if (!object_ix_hashsz)
 517                 return NULL;
 518
 519         i = locate_object_entry_hash(sha1);
 520         if (0 <= i)
 521                 return &objects[object_ix[i]-1];
 522         return NULL;
 523 }
 524
 525 static void rehash_objects(void)
 526 {
 527         int i;
 528         struct object_entry *oe;
 529
 530         object_ix_hashsz = nr_objects * 3;
 531         if (object_ix_hashsz < 1024)
 532                 object_ix_hashsz = 1024;
 533         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 534         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 535         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 536                 int ix = locate_object_entry_hash(oe->sha1);
 537                 if (0 <= ix)
 538                         continue;
 539                 ix = -1 - ix;
 540                 object_ix[ix] = i + 1;
 541         }
 542 }
 543
 544 static unsigned name_hash(const char *name)
 545 {
 546         unsigned char c;
 547         unsigned hash = 0;
 548
 549         /*
 550          * This effectively just creates a sortable number from the
 551          * last sixteen non-whitespace characters. Last characters
 552          * count "most", so things that end in ".c" sort together.
 553          */
 554         while ((c = *name++) != 0) {
 555                 if (isspace(c))
 556                         continue;
 557                 hash = (hash >> 2) + (c << 24);
 558         }
 559         return hash;
 560 }
 561
 562 static int add_object_entry(const unsigned char *sha1, unsigned hash, int exclude)
 563 {
 564         unsigned int idx = nr_objects;
 565         struct object_entry *entry;
 566         struct packed_git *p;
 567         unsigned int found_offset = 0;
 568         struct packed_git *found_pack = NULL;
 569         int ix, status = 0;
 570
 571         if (!exclude) {
 572                 for (p = packed_git; p; p = p->next) {
 573                         struct pack_entry e;
 574                         if (find_pack_entry_one(sha1, &e, p)) {
 575                                 if (incremental)
 576                                         return 0;
 577                                 if (local && !p->pack_local)
 578                                         return 0;
 579                                 if (!found_pack) {
 580                                         found_offset = e.offset;
 581                                         found_pack = e.p;
 582                                 }
 583                         }
 584                 }
 585         }
 586         if ((entry = locate_object_entry(sha1)) != NULL)
 587                 goto already_added;
 588
 589         if (idx >= nr_alloc) {
 590                 unsigned int needed = (idx + 1024) * 3 / 2;
 591                 objects = xrealloc(objects, needed * sizeof(*entry));
 592                 nr_alloc = needed;
 593         }
 594         entry = objects + idx;
 595         nr_objects = idx + 1;
 596         memset(entry, 0, sizeof(*entry));
 597         hashcpy(entry->sha1, sha1);
 598         entry->hash = hash;
 599
 600         if (object_ix_hashsz * 3 <= nr_objects * 4)
 601                 rehash_objects();
 602         else {
 603                 ix = locate_object_entry_hash(entry->sha1);
 604                 if (0 <= ix)
 605                         die("internal error in object hashing.");
 606                 object_ix[-1 - ix] = idx + 1;
 607         }
 608         status = 1;
 609
 610  already_added:
 611         if (progress_update) {
 612                 fprintf(stderr, "Counting objects...%d\r", nr_objects);
 613                 progress_update = 0;
 614         }
 615         if (exclude)
 616                 entry->preferred_base = 1;
 617         else {
 618                 if (found_pack) {
 619                         entry->in_pack = found_pack;
 620                         entry->in_pack_offset = found_offset;
 621                 }
 622         }
 623         return status;
 624 }
 625
 626 struct pbase_tree_cache {
 627         unsigned char sha1[20];
 628         int ref;
 629         int temporary;
 630         void *tree_data;
 631         unsigned long tree_size;
 632 };
 633
 634 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 635 static int pbase_tree_cache_ix(const unsigned char *sha1)
 636 {
 637         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 638 }
 639 static int pbase_tree_cache_ix_incr(int ix)
 640 {
 641         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 642 }
 643
 644 static struct pbase_tree {
 645         struct pbase_tree *next;
 646         /* This is a phony "cache" entry; we are not
 647          * going to evict it nor find it through _get()
 648          * mechanism -- this is for the toplevel node that
 649          * would almost always change with any commit.
 650          */
 651         struct pbase_tree_cache pcache;
 652 } *pbase_tree;
 653
 654 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 655 {
 656         struct pbase_tree_cache *ent, *nent;
 657         void *data;
 658         unsigned long size;
 659         char type[20];
 660         int neigh;
 661         int my_ix = pbase_tree_cache_ix(sha1);
 662         int available_ix = -1;
 663
 664         /* pbase-tree-cache acts as a limited hashtable.
 665          * your object will be found at your index or within a few
 666          * slots after that slot if it is cached.
 667          */
 668         for (neigh = 0; neigh < 8; neigh++) {
 669                 ent = pbase_tree_cache[my_ix];
 670                 if (ent && !hashcmp(ent->sha1, sha1)) {
 671                         ent->ref++;
 672                         return ent;
 673                 }
 674                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 675                          ((0 <= available_ix) &&
 676                           (!ent && pbase_tree_cache[available_ix])))
 677                         available_ix = my_ix;
 678                 if (!ent)
 679                         break;
 680                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 681         }
 682
 683         /* Did not find one.  Either we got a bogus request or
 684          * we need to read and perhaps cache.
 685          */
 686         data = read_sha1_file(sha1, type, &size);
 687         if (!data)
 688                 return NULL;
 689         if (strcmp(type, tree_type)) {
 690                 free(data);
 691                 return NULL;
 692         }
 693
 694         /* We need to either cache or return a throwaway copy */
 695
 696         if (available_ix < 0)
 697                 ent = NULL;
 698         else {
 699                 ent = pbase_tree_cache[available_ix];
 700                 my_ix = available_ix;
 701         }
 702
 703         if (!ent) {
 704                 nent = xmalloc(sizeof(*nent));
 705                 nent->temporary = (available_ix < 0);
 706         }
 707         else {
 708                 /* evict and reuse */
 709                 free(ent->tree_data);
 710                 nent = ent;
 711         }
 712         hashcpy(nent->sha1, sha1);
 713         nent->tree_data = data;
 714         nent->tree_size = size;
 715         nent->ref = 1;
 716         if (!nent->temporary)
 717                 pbase_tree_cache[my_ix] = nent;
 718         return nent;
 719 }
 720
 721 static void pbase_tree_put(struct pbase_tree_cache *cache)
 722 {
 723         if (!cache->temporary) {
 724                 cache->ref--;
 725                 return;
 726         }
 727         free(cache->tree_data);
 728         free(cache);
 729 }
 730
 731 static int name_cmp_len(const char *name)
 732 {
 733         int i;
 734         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 735                 ;
 736         return i;
 737 }
 738
 739 static void add_pbase_object(struct tree_desc *tree,
 740                              const char *name,
 741                              int cmplen,
 742                              const char *fullname)
 743 {
 744         struct name_entry entry;
 745
 746         while (tree_entry(tree,&entry)) {
 747                 unsigned long size;
 748                 char type[20];
 749
 750                 if (entry.pathlen != cmplen ||
 751                     memcmp(entry.path, name, cmplen) ||
 752                     !has_sha1_file(entry.sha1) ||
 753                     sha1_object_info(entry.sha1, type, &size))
 754                         continue;
 755                 if (name[cmplen] != '/') {
 756                         unsigned hash = name_hash(fullname);
 757                         add_object_entry(entry.sha1, hash, 1);
 758                         return;
 759                 }
 760                 if (!strcmp(type, tree_type)) {
 761                         struct tree_desc sub;
 762                         struct pbase_tree_cache *tree;
 763                         const char *down = name+cmplen+1;
 764                         int downlen = name_cmp_len(down);
 765
 766                         tree = pbase_tree_get(entry.sha1);
 767                         if (!tree)
 768                                 return;
 769                         sub.buf = tree->tree_data;
 770                         sub.size = tree->tree_size;
 771
 772                         add_pbase_object(&sub, down, downlen, fullname);
 773                         pbase_tree_put(tree);
 774                 }
 775         }
 776 }
 777
 778 static unsigned *done_pbase_paths;
 779 static int done_pbase_paths_num;
 780 static int done_pbase_paths_alloc;
 781 static int done_pbase_path_pos(unsigned hash)
 782 {
 783         int lo = 0;
 784         int hi = done_pbase_paths_num;
 785         while (lo < hi) {
 786                 int mi = (hi + lo) / 2;
 787                 if (done_pbase_paths[mi] == hash)
 788                         return mi;
 789                 if (done_pbase_paths[mi] < hash)
 790                         hi = mi;
 791                 else
 792                         lo = mi + 1;
 793         }
 794         return -lo-1;
 795 }
 796
 797 static int check_pbase_path(unsigned hash)
 798 {
 799         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 800         if (0 <= pos)
 801                 return 1;
 802         pos = -pos - 1;
 803         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 804                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 805                 done_pbase_paths = xrealloc(done_pbase_paths,
 806                                             done_pbase_paths_alloc *
 807                                             sizeof(unsigned));
 808         }
 809         done_pbase_paths_num++;
 810         if (pos < done_pbase_paths_num)
 811                 memmove(done_pbase_paths + pos + 1,
 812                         done_pbase_paths + pos,
 813                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 814         done_pbase_paths[pos] = hash;
 815         return 0;
 816 }
 817
 818 static void add_preferred_base_object(char *name, unsigned hash)
 819 {
 820         struct pbase_tree *it;
 821         int cmplen = name_cmp_len(name);
 822
 823         if (check_pbase_path(hash))
 824                 return;
 825
 826         for (it = pbase_tree; it; it = it->next) {
 827                 if (cmplen == 0) {
 828                         hash = name_hash("");
 829                         add_object_entry(it->pcache.sha1, hash, 1);
 830                 }
 831                 else {
 832                         struct tree_desc tree;
 833                         tree.buf = it->pcache.tree_data;
 834                         tree.size = it->pcache.tree_size;
 835                         add_pbase_object(&tree, name, cmplen, name);
 836                 }
 837         }
 838 }
 839
 840 static void add_preferred_base(unsigned char *sha1)
 841 {
 842         struct pbase_tree *it;
 843         void *data;
 844         unsigned long size;
 845         unsigned char tree_sha1[20];
 846
 847         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 848         if (!data)
 849                 return;
 850
 851         for (it = pbase_tree; it; it = it->next) {
 852                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 853                         free(data);
 854                         return;
 855                 }
 856         }
 857
 858         it = xcalloc(1, sizeof(*it));
 859         it->next = pbase_tree;
 860         pbase_tree = it;
 861
 862         hashcpy(it->pcache.sha1, tree_sha1);
 863         it->pcache.tree_data = data;
 864         it->pcache.tree_size = size;
 865 }
 866
 867 static void check_object(struct object_entry *entry)
 868 {
 869         char type[20];
 870
 871         if (entry->in_pack && !entry->preferred_base) {
 872                 unsigned char base[20];
 873                 unsigned long size;
 874                 struct object_entry *base_entry;
 875
 876                 /* We want in_pack_type even if we do not reuse delta.
 877                  * There is no point not reusing non-delta representations.
 878                  */
 879                 check_reuse_pack_delta(entry->in_pack,
 880                                        entry->in_pack_offset,
 881                                        base, &size,
 882                                        &entry->in_pack_type);
 883
 884                 /* Check if it is delta, and the base is also an object
 885                  * we are going to pack.  If so we will reuse the existing
 886                  * delta.
 887                  */
 888                 if (!no_reuse_delta &&
 889                     entry->in_pack_type == OBJ_DELTA &&
 890                     (base_entry = locate_object_entry(base)) &&
 891                     (!base_entry->preferred_base)) {
 892
 893                         /* Depth value does not matter - find_deltas()
 894                          * will never consider reused delta as the
 895                          * base object to deltify other objects
 896                          * against, in order to avoid circular deltas.
 897                          */
 898
 899                         /* uncompressed size of the delta data */
 900                         entry->size = entry->delta_size = size;
 901                         entry->delta = base_entry;
 902                         entry->type = OBJ_DELTA;
 903
 904                         entry->delta_sibling = base_entry->delta_child;
 905                         base_entry->delta_child = entry;
 906
 907                         return;
 908                 }
 909                 /* Otherwise we would do the usual */
 910         }
 911
 912         if (sha1_object_info(entry->sha1, type, &entry->size))
 913                 die("unable to get type of object %s",
 914                     sha1_to_hex(entry->sha1));
 915
 916         if (!strcmp(type, commit_type)) {
 917                 entry->type = OBJ_COMMIT;
 918         } else if (!strcmp(type, tree_type)) {
 919                 entry->type = OBJ_TREE;
 920         } else if (!strcmp(type, blob_type)) {
 921                 entry->type = OBJ_BLOB;
 922         } else if (!strcmp(type, tag_type)) {
 923                 entry->type = OBJ_TAG;
 924         } else
 925                 die("unable to pack object %s of type %s",
 926                     sha1_to_hex(entry->sha1), type);
 927 }
 928
 929 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
 930 {
 931         struct object_entry *child = me->delta_child;
 932         unsigned int m = n;
 933         while (child) {
 934                 unsigned int c = check_delta_limit(child, n + 1);
 935                 if (m < c)
 936                         m = c;
 937                 child = child->delta_sibling;
 938         }
 939         return m;
 940 }
 941
 942 static void get_object_details(void)
 943 {
 944         int i;
 945         struct object_entry *entry;
 946
 947         prepare_pack_ix();
 948         for (i = 0, entry = objects; i < nr_objects; i++, entry++)
 949                 check_object(entry);
 950
 951         if (nr_objects == nr_result) {
 952                 /*
 953                  * Depth of objects that depend on the entry -- this
 954                  * is subtracted from depth-max to break too deep
 955                  * delta chain because of delta data reusing.
 956                  * However, we loosen this restriction when we know we
 957                  * are creating a thin pack -- it will have to be
 958                  * expanded on the other end anyway, so do not
 959                  * artificially cut the delta chain and let it go as
 960                  * deep as it wants.
 961                  */
 962                 for (i = 0, entry = objects; i < nr_objects; i++, entry++)
 963                         if (!entry->delta && entry->delta_child)
 964                                 entry->delta_limit =
 965                                         check_delta_limit(entry, 1);
 966         }
 967 }
 968
 969 typedef int (*entry_sort_t)(const struct object_entry *, const struct object_entry *);
 970
 971 static entry_sort_t current_sort;
 972
 973 static int sort_comparator(const void *_a, const void *_b)
 974 {
 975         struct object_entry *a = *(struct object_entry **)_a;
 976         struct object_entry *b = *(struct object_entry **)_b;
 977         return current_sort(a,b);
 978 }
 979
 980 static struct object_entry **create_sorted_list(entry_sort_t sort)
 981 {
 982         struct object_entry **list = xmalloc(nr_objects * sizeof(struct object_entry *));
 983         int i;
 984
 985         for (i = 0; i < nr_objects; i++)
 986                 list[i] = objects + i;
 987         current_sort = sort;
 988         qsort(list, nr_objects, sizeof(struct object_entry *), sort_comparator);
 989         return list;
 990 }
 991
 992 static int sha1_sort(const struct object_entry *a, const struct object_entry *b)
 993 {
 994         return hashcmp(a->sha1, b->sha1);
 995 }
 996
 997 static struct object_entry **create_final_object_list(void)
 998 {
 999         struct object_entry **list;
1000         int i, j;
1001
1002         for (i = nr_result = 0; i < nr_objects; i++)
1003                 if (!objects[i].preferred_base)
1004                         nr_result++;
1005         list = xmalloc(nr_result * sizeof(struct object_entry *));
1006         for (i = j = 0; i < nr_objects; i++) {
1007                 if (!objects[i].preferred_base)
1008                         list[j++] = objects + i;
1009         }
1010         current_sort = sha1_sort;
1011         qsort(list, nr_result, sizeof(struct object_entry *), sort_comparator);
1012         return list;
1013 }
1014
1015 static int type_size_sort(const struct object_entry *a, const struct object_entry *b)
1016 {
1017         if (a->type < b->type)
1018                 return -1;
1019         if (a->type > b->type)
1020                 return 1;
1021         if (a->hash < b->hash)
1022                 return -1;
1023         if (a->hash > b->hash)
1024                 return 1;
1025         if (a->preferred_base < b->preferred_base)
1026                 return -1;
1027         if (a->preferred_base > b->preferred_base)
1028                 return 1;
1029         if (a->size < b->size)
1030                 return -1;
1031         if (a->size > b->size)
1032                 return 1;
1033         return a < b ? -1 : (a > b);
1034 }
1035
1036 struct unpacked {
1037         struct object_entry *entry;
1038         void *data;
1039         struct delta_index *index;
1040 };
1041
1042 /*
1043  * We search for deltas _backwards_ in a list sorted by type and
1044  * by size, so that we see progressively smaller and smaller files.
1045  * That's because we prefer deltas to be from the bigger file
1046  * to the smaller - deletes are potentially cheaper, but perhaps
1047  * more importantly, the bigger file is likely the more recent
1048  * one.
1049  */
1050 static int try_delta(struct unpacked *trg, struct unpacked *src,
1051                      unsigned max_depth)
1052 {
1053         struct object_entry *trg_entry = trg->entry;
1054         struct object_entry *src_entry = src->entry;
1055         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1056         char type[10];
1057         void *delta_buf;
1058
1059         /* Don't bother doing diffs between different types */
1060         if (trg_entry->type != src_entry->type)
1061                 return -1;
1062
1063         /* We do not compute delta to *create* objects we are not
1064          * going to pack.
1065          */
1066         if (trg_entry->preferred_base)
1067                 return -1;
1068
1069         /*
1070          * We do not bother to try a delta that we discarded
1071          * on an earlier try, but only when reusing delta data.
1072          */
1073         if (!no_reuse_delta && trg_entry->in_pack &&
1074             trg_entry->in_pack == src_entry->in_pack)
1075                 return 0;
1076
1077         /*
1078          * If the current object is at pack edge, take the depth the
1079          * objects that depend on the current object into account --
1080          * otherwise they would become too deep.
1081          */
1082         if (trg_entry->delta_child) {
1083                 if (max_depth <= trg_entry->delta_limit)
1084                         return 0;
1085                 max_depth -= trg_entry->delta_limit;
1086         }
1087         if (src_entry->depth >= max_depth)
1088                 return 0;
1089
1090         /* Now some size filtering heuristics. */
1091         trg_size = trg_entry->size;
1092         max_size = trg_size/2 - 20;
1093         max_size = max_size * (max_depth - src_entry->depth) / max_depth;
1094         if (max_size == 0)
1095                 return 0;
1096         if (trg_entry->delta && trg_entry->delta_size <= max_size)
1097                 max_size = trg_entry->delta_size-1;
1098         src_size = src_entry->size;
1099         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1100         if (sizediff >= max_size)
1101                 return 0;
1102
1103         /* Load data if not already done */
1104         if (!trg->data) {
1105                 trg->data = read_sha1_file(trg_entry->sha1, type, &sz);
1106                 if (sz != trg_size)
1107                         die("object %s inconsistent object length (%lu vs %lu)",
1108                             sha1_to_hex(trg_entry->sha1), sz, trg_size);
1109         }
1110         if (!src->data) {
1111                 src->data = read_sha1_file(src_entry->sha1, type, &sz);
1112                 if (sz != src_size)
1113                         die("object %s inconsistent object length (%lu vs %lu)",
1114                             sha1_to_hex(src_entry->sha1), sz, src_size);
1115         }
1116         if (!src->index) {
1117                 src->index = create_delta_index(src->data, src_size);
1118                 if (!src->index)
1119                         die("out of memory");
1120         }
1121
1122         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1123         if (!delta_buf)
1124                 return 0;
1125
1126         trg_entry->delta = src_entry;
1127         trg_entry->delta_size = delta_size;
1128         trg_entry->depth = src_entry->depth + 1;
1129         free(delta_buf);
1130         return 1;
1131 }
1132
1133 static void progress_interval(int signum)
1134 {
1135         progress_update = 1;
1136 }
1137
1138 static void find_deltas(struct object_entry **list, int window, int depth)
1139 {
1140         int i, idx;
1141         unsigned int array_size = window * sizeof(struct unpacked);
1142         struct unpacked *array = xmalloc(array_size);
1143         unsigned processed = 0;
1144         unsigned last_percent = 999;
1145
1146         memset(array, 0, array_size);
1147         i = nr_objects;
1148         idx = 0;
1149         if (progress)
1150                 fprintf(stderr, "Deltifying %d objects.\n", nr_result);
1151
1152         while (--i >= 0) {
1153                 struct object_entry *entry = list[i];
1154                 struct unpacked *n = array + idx;
1155                 int j;
1156
1157                 if (!entry->preferred_base)
1158                         processed++;
1159
1160                 if (progress) {
1161                         unsigned percent = processed * 100 / nr_result;
1162                         if (percent != last_percent || progress_update) {
1163                                 fprintf(stderr, "%4u%% (%u/%u) done\r",
1164                                         percent, processed, nr_result);
1165                                 progress_update = 0;
1166                                 last_percent = percent;
1167                         }
1168                 }
1169
1170                 if (entry->delta)
1171                         /* This happens if we decided to reuse existing
1172                          * delta from a pack.  "!no_reuse_delta &&" is implied.
1173                          */
1174                         continue;
1175
1176                 if (entry->size < 50)
1177                         continue;
1178                 free_delta_index(n->index);
1179                 n->index = NULL;
1180                 free(n->data);
1181                 n->data = NULL;
1182                 n->entry = entry;
1183
1184                 j = window;
1185                 while (--j > 0) {
1186                         unsigned int other_idx = idx + j;
1187                         struct unpacked *m;
1188                         if (other_idx >= window)
1189                                 other_idx -= window;
1190                         m = array + other_idx;
1191                         if (!m->entry)
1192                                 break;
1193                         if (try_delta(n, m, depth) < 0)
1194                                 break;
1195                 }
1196                 /* if we made n a delta, and if n is already at max
1197                  * depth, leaving it in the window is pointless.  we
1198                  * should evict it first.
1199                  */
1200                 if (entry->delta && depth <= entry->depth)
1201                         continue;
1202
1203                 idx++;
1204                 if (idx >= window)
1205                         idx = 0;
1206         }
1207
1208         if (progress)
1209                 fputc('\n', stderr);
1210
1211         for (i = 0; i < window; ++i) {
1212                 free_delta_index(array[i].index);
1213                 free(array[i].data);
1214         }
1215         free(array);
1216 }
1217
1218 static void prepare_pack(int window, int depth)
1219 {
1220         get_object_details();
1221         sorted_by_type = create_sorted_list(type_size_sort);
1222         if (window && depth)
1223                 find_deltas(sorted_by_type, window+1, depth);
1224 }
1225
1226 static int reuse_cached_pack(unsigned char *sha1)
1227 {
1228         static const char cache[] = "pack-cache/pack-%s.%s";
1229         char *cached_pack, *cached_idx;
1230         int ifd, ofd, ifd_ix = -1;
1231
1232         cached_pack = git_path(cache, sha1_to_hex(sha1), "pack");
1233         ifd = open(cached_pack, O_RDONLY);
1234         if (ifd < 0)
1235                 return 0;
1236
1237         if (!pack_to_stdout) {
1238                 cached_idx = git_path(cache, sha1_to_hex(sha1), "idx");
1239                 ifd_ix = open(cached_idx, O_RDONLY);
1240                 if (ifd_ix < 0) {
1241                         close(ifd);
1242                         return 0;
1243                 }
1244         }
1245
1246         if (progress)
1247                 fprintf(stderr, "Reusing %d objects pack %s\n", nr_objects,
1248                         sha1_to_hex(sha1));
1249
1250         if (pack_to_stdout) {
1251                 if (copy_fd(ifd, 1))
1252                         exit(1);
1253                 close(ifd);
1254         }
1255         else {
1256                 char name[PATH_MAX];
1257                 snprintf(name, sizeof(name),
1258                          "%s-%s.%s", base_name, sha1_to_hex(sha1), "pack");
1259                 ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
1260                 if (ofd < 0)
1261                         die("unable to open %s (%s)", name, strerror(errno));
1262                 if (copy_fd(ifd, ofd))
1263                         exit(1);
1264                 close(ifd);
1265
1266                 snprintf(name, sizeof(name),
1267                          "%s-%s.%s", base_name, sha1_to_hex(sha1), "idx");
1268                 ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
1269                 if (ofd < 0)
1270                         die("unable to open %s (%s)", name, strerror(errno));
1271                 if (copy_fd(ifd_ix, ofd))
1272                         exit(1);
1273                 close(ifd_ix);
1274                 puts(sha1_to_hex(sha1));
1275         }
1276
1277         return 1;
1278 }
1279
1280 static void setup_progress_signal(void)
1281 {
1282         struct sigaction sa;
1283         struct itimerval v;
1284
1285         memset(&sa, 0, sizeof(sa));
1286         sa.sa_handler = progress_interval;
1287         sigemptyset(&sa.sa_mask);
1288         sa.sa_flags = SA_RESTART;
1289         sigaction(SIGALRM, &sa, NULL);
1290
1291         v.it_interval.tv_sec = 1;
1292         v.it_interval.tv_usec = 0;
1293         v.it_value = v.it_interval;
1294         setitimer(ITIMER_REAL, &v, NULL);
1295 }
1296
1297 static int git_pack_config(const char *k, const char *v)
1298 {
1299         if(!strcmp(k, "pack.window")) {
1300                 window = git_config_int(k, v);
1301                 return 0;
1302         }
1303         return git_default_config(k, v);
1304 }
1305
1306 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
1307 {
1308         SHA_CTX ctx;
1309         char line[40 + 1 + PATH_MAX + 2];
1310         int depth = 10;
1311         struct object_entry **list;
1312         int num_preferred_base = 0;
1313         int i;
1314
1315         git_config(git_pack_config);
1316
1317         progress = isatty(2);
1318         for (i = 1; i < argc; i++) {
1319                 const char *arg = argv[i];
1320
1321                 if (*arg == '-') {
1322                         if (!strcmp("--non-empty", arg)) {
1323                                 non_empty = 1;
1324                                 continue;
1325                         }
1326                         if (!strcmp("--local", arg)) {
1327                                 local = 1;
1328                                 continue;
1329                         }
1330                         if (!strcmp("--progress", arg)) {
1331                                 progress = 1;
1332                                 continue;
1333                         }
1334                         if (!strcmp("--incremental", arg)) {
1335                                 incremental = 1;
1336                                 continue;
1337                         }
1338                         if (!strncmp("--window=", arg, 9)) {
1339                                 char *end;
1340                                 window = strtoul(arg+9, &end, 0);
1341                                 if (!arg[9] || *end)
1342                                         usage(pack_usage);
1343                                 continue;
1344                         }
1345                         if (!strncmp("--depth=", arg, 8)) {
1346                                 char *end;
1347                                 depth = strtoul(arg+8, &end, 0);
1348                                 if (!arg[8] || *end)
1349                                         usage(pack_usage);
1350                                 continue;
1351                         }
1352                         if (!strcmp("--progress", arg)) {
1353                                 progress = 1;
1354                                 continue;
1355                         }
1356                         if (!strcmp("-q", arg)) {
1357                                 progress = 0;
1358                                 continue;
1359                         }
1360                         if (!strcmp("--no-reuse-delta", arg)) {
1361                                 no_reuse_delta = 1;
1362                                 continue;
1363                         }
1364                         if (!strcmp("--stdout", arg)) {
1365                                 pack_to_stdout = 1;
1366                                 continue;
1367                         }
1368                         usage(pack_usage);
1369                 }
1370                 if (base_name)
1371                         usage(pack_usage);
1372                 base_name = arg;
1373         }
1374
1375         if (pack_to_stdout != !base_name)
1376                 usage(pack_usage);
1377
1378         prepare_packed_git();
1379
1380         if (progress) {
1381                 fprintf(stderr, "Generating pack...\n");
1382                 setup_progress_signal();
1383         }
1384
1385         for (;;) {
1386                 unsigned char sha1[20];
1387                 unsigned hash;
1388
1389                 if (!fgets(line, sizeof(line), stdin)) {
1390                         if (feof(stdin))
1391                                 break;
1392                         if (!ferror(stdin))
1393                                 die("fgets returned NULL, not EOF, not error!");
1394                         if (errno != EINTR)
1395                                 die("fgets: %s", strerror(errno));
1396                         clearerr(stdin);
1397                         continue;
1398                 }
1399
1400                 if (line[0] == '-') {
1401                         if (get_sha1_hex(line+1, sha1))
1402                                 die("expected edge sha1, got garbage:\n %s",
1403                                     line+1);
1404                         if (num_preferred_base++ < window)
1405                                 add_preferred_base(sha1);
1406                         continue;
1407                 }
1408                 if (get_sha1_hex(line, sha1))
1409                         die("expected sha1, got garbage:\n %s", line);
1410                 hash = name_hash(line+41);
1411                 add_preferred_base_object(line+41, hash);
1412                 add_object_entry(sha1, hash, 0);
1413         }
1414         if (progress)
1415                 fprintf(stderr, "Done counting %d objects.\n", nr_objects);
1416         sorted_by_sha = create_final_object_list();
1417         if (non_empty && !nr_result)
1418                 return 0;
1419
1420         SHA1_Init(&ctx);
1421         list = sorted_by_sha;
1422         for (i = 0; i < nr_result; i++) {
1423                 struct object_entry *entry = *list++;
1424                 SHA1_Update(&ctx, entry->sha1, 20);
1425         }
1426         SHA1_Final(object_list_sha1, &ctx);
1427         if (progress && (nr_objects != nr_result))
1428                 fprintf(stderr, "Result has %d objects.\n", nr_result);
1429
1430         if (reuse_cached_pack(object_list_sha1))
1431                 ;
1432         else {
1433                 if (nr_result)
1434                         prepare_pack(window, depth);
1435                 if (progress && pack_to_stdout) {
1436                         /* the other end usually displays progress itself */
1437                         struct itimerval v = {{0,},};
1438                         setitimer(ITIMER_REAL, &v, NULL);
1439                         signal(SIGALRM, SIG_IGN );
1440                         progress_update = 0;
1441                 }
1442                 write_pack_file();
1443                 if (!pack_to_stdout) {
1444                         write_index_file();
1445                         puts(sha1_to_hex(object_list_sha1));
1446                 }
1447         }
1448         if (progress)
1449                 fprintf(stderr, "Total %d, written %d (delta %d), reused %d (delta %d)\n",
1450                         nr_result, written, written_delta, reused, reused_delta);
1451         return 0;
1452 }