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 "diff.h"
  13 #include "revision.h"
  14 #include "list-objects.h"
  15 #include <sys/time.h>
  16 #include <signal.h>
  17
  18 static const char pack_usage[] = "git-pack-objects [-q] [--no-reuse-delta] [--delta-base-offset] [--non-empty] [--local] [--incremental] [--window=N] [--depth=N] [--revs [--unpacked | --all]*] [--stdout | base-name] <ref-list | <object-list]";
  19
  20 struct object_entry {
  21         unsigned char sha1[20];
  22         unsigned long size;     /* uncompressed size */
  23         unsigned long offset;   /* offset into the final pack file;
  24                                  * nonzero if already written.
  25                                  */
  26         unsigned int depth;     /* delta depth */
  27         unsigned int delta_limit;       /* base adjustment for in-pack delta */
  28         unsigned int hash;      /* name hint hash */
  29         enum object_type type;
  30         enum object_type in_pack_type;  /* could be delta */
  31         unsigned long delta_size;       /* delta data size (uncompressed) */
  32 #define in_pack_header_size delta_size  /* only when reusing pack data */
  33         struct object_entry *delta;     /* delta base object */
  34         struct packed_git *in_pack;     /* already in pack */
  35         unsigned int in_pack_offset;
  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         int preferred_base;     /* we do not pack this, but is encouraged to
  41                                  * be used as the base objectto delta huge
  42                                  * objects against.
  43                                  */
  44 };
  45
  46 /*
  47  * Objects we are going to pack are collected in objects array (dynamically
  48  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  49  * in the order we see -- typically rev-list --objects order that gives us
  50  * nice "minimum seek" order.
  51  *
  52  * sorted-by-sha ans sorted-by-type are arrays of pointers that point at
  53  * elements in the objects array.  The former is used to build the pack
  54  * index (lists object names in the ascending order to help offset lookup),
  55  * and the latter is used to group similar things together by try_delta()
  56  * heuristics.
  57  */
  58
  59 static unsigned char object_list_sha1[20];
  60 static int non_empty;
  61 static int no_reuse_delta;
  62 static int local;
  63 static int incremental;
  64 static int allow_ofs_delta;
  65
  66 static struct object_entry **sorted_by_sha, **sorted_by_type;
  67 static struct object_entry *objects;
  68 static int nr_objects, nr_alloc, nr_result;
  69 static const char *base_name;
  70 static unsigned char pack_file_sha1[20];
  71 static int progress = 1;
  72 static volatile sig_atomic_t progress_update;
  73 static int window = 10;
  74 static int pack_to_stdout;
  75 static int num_preferred_base;
  76
  77 /*
  78  * The object names in objects array are hashed with this hashtable,
  79  * to help looking up the entry by object name.  Binary search from
  80  * sorted_by_sha is also possible but this was easier to code and faster.
  81  * This hashtable is built after all the objects are seen.
  82  */
  83 static int *object_ix;
  84 static int object_ix_hashsz;
  85
  86 /*
  87  * Pack index for existing packs give us easy access to the offsets into
  88  * corresponding pack file where each object's data starts, but the entries
  89  * do not store the size of the compressed representation (uncompressed
  90  * size is easily available by examining the pack entry header).  It is
  91  * also rather expensive to find the sha1 for an object given its offset.
  92  *
  93  * We build a hashtable of existing packs (pack_revindex), and keep reverse
  94  * index here -- pack index file is sorted by object name mapping to offset;
  95  * this pack_revindex[].revindex array is a list of offset/index_nr pairs
  96  * ordered by offset, so if you know the offset of an object, next offset
  97  * is where its packed representation ends and the index_nr can be used to
  98  * get the object sha1 from the main index.
  99  */
 100 struct revindex_entry {
 101         unsigned int offset;
 102         unsigned int nr;
 103 };
 104 struct pack_revindex {
 105         struct packed_git *p;
 106         struct revindex_entry *revindex;
 107 };
 108 static struct  pack_revindex *pack_revindex;
 109 static int pack_revindex_hashsz;
 110
 111 /*
 112  * stats
 113  */
 114 static int written;
 115 static int written_delta;
 116 static int reused;
 117 static int reused_delta;
 118
 119 static int pack_revindex_ix(struct packed_git *p)
 120 {
 121         unsigned long ui = (unsigned long)p;
 122         int i;
 123
 124         ui = ui ^ (ui >> 16); /* defeat structure alignment */
 125         i = (int)(ui % pack_revindex_hashsz);
 126         while (pack_revindex[i].p) {
 127                 if (pack_revindex[i].p == p)
 128                         return i;
 129                 if (++i == pack_revindex_hashsz)
 130                         i = 0;
 131         }
 132         return -1 - i;
 133 }
 134
 135 static void prepare_pack_ix(void)
 136 {
 137         int num;
 138         struct packed_git *p;
 139         for (num = 0, p = packed_git; p; p = p->next)
 140                 num++;
 141         if (!num)
 142                 return;
 143         pack_revindex_hashsz = num * 11;
 144         pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
 145         for (p = packed_git; p; p = p->next) {
 146                 num = pack_revindex_ix(p);
 147                 num = - 1 - num;
 148                 pack_revindex[num].p = p;
 149         }
 150         /* revindex elements are lazily initialized */
 151 }
 152
 153 static int cmp_offset(const void *a_, const void *b_)
 154 {
 155         const struct revindex_entry *a = a_;
 156         const struct revindex_entry *b = b_;
 157         return (a->offset < b->offset) ? -1 : (a->offset > b->offset) ? 1 : 0;
 158 }
 159
 160 /*
 161  * Ordered list of offsets of objects in the pack.
 162  */
 163 static void prepare_pack_revindex(struct pack_revindex *rix)
 164 {
 165         struct packed_git *p = rix->p;
 166         int num_ent = num_packed_objects(p);
 167         int i;
 168         void *index = p->index_base + 256;
 169
 170         rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1));
 171         for (i = 0; i < num_ent; i++) {
 172                 unsigned int hl = *((unsigned int *)((char *) index + 24*i));
 173                 rix->revindex[i].offset = ntohl(hl);
 174                 rix->revindex[i].nr = i;
 175         }
 176         /* This knows the pack format -- the 20-byte trailer
 177          * follows immediately after the last object data.
 178          */
 179         rix->revindex[num_ent].offset = p->pack_size - 20;
 180         rix->revindex[num_ent].nr = -1;
 181         qsort(rix->revindex, num_ent, sizeof(*rix->revindex), cmp_offset);
 182 }
 183
 184 static struct revindex_entry * find_packed_object(struct packed_git *p,
 185                                                   unsigned int ofs)
 186 {
 187         int num;
 188         int lo, hi;
 189         struct pack_revindex *rix;
 190         struct revindex_entry *revindex;
 191         num = pack_revindex_ix(p);
 192         if (num < 0)
 193                 die("internal error: pack revindex uninitialized");
 194         rix = &pack_revindex[num];
 195         if (!rix->revindex)
 196                 prepare_pack_revindex(rix);
 197         revindex = rix->revindex;
 198         lo = 0;
 199         hi = num_packed_objects(p) + 1;
 200         do {
 201                 int mi = (lo + hi) / 2;
 202                 if (revindex[mi].offset == ofs) {
 203                         return revindex + mi;
 204                 }
 205                 else if (ofs < revindex[mi].offset)
 206                         hi = mi;
 207                 else
 208                         lo = mi + 1;
 209         } while (lo < hi);
 210         die("internal error: pack revindex corrupt");
 211 }
 212
 213 static unsigned long find_packed_object_size(struct packed_git *p,
 214                                              unsigned long ofs)
 215 {
 216         struct revindex_entry *entry = find_packed_object(p, ofs);
 217         return entry[1].offset - ofs;
 218 }
 219
 220 static unsigned char *find_packed_object_name(struct packed_git *p,
 221                                               unsigned long ofs)
 222 {
 223         struct revindex_entry *entry = find_packed_object(p, ofs);
 224         return (unsigned char *)(p->index_base + 256) + 24 * entry->nr + 4;
 225 }
 226
 227 static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
 228 {
 229         unsigned long othersize, delta_size;
 230         char type[10];
 231         void *otherbuf = read_sha1_file(entry->delta->sha1, type, &othersize);
 232         void *delta_buf;
 233
 234         if (!otherbuf)
 235                 die("unable to read %s", sha1_to_hex(entry->delta->sha1));
 236         delta_buf = diff_delta(otherbuf, othersize,
 237                                buf, size, &delta_size, 0);
 238         if (!delta_buf || delta_size != entry->delta_size)
 239                 die("delta size changed");
 240         free(buf);
 241         free(otherbuf);
 242         return delta_buf;
 243 }
 244
 245 /*
 246  * The per-object header is a pretty dense thing, which is
 247  *  - first byte: low four bits are "size", then three bits of "type",
 248  *    and the high bit is "size continues".
 249  *  - each byte afterwards: low seven bits are size continuation,
 250  *    with the high bit being "size continues"
 251  */
 252 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 253 {
 254         int n = 1;
 255         unsigned char c;
 256
 257         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 258                 die("bad type %d", type);
 259
 260         c = (type << 4) | (size & 15);
 261         size >>= 4;
 262         while (size) {
 263                 *hdr++ = c | 0x80;
 264                 c = size & 0x7f;
 265                 size >>= 7;
 266                 n++;
 267         }
 268         *hdr = c;
 269         return n;
 270 }
 271
 272 /*
 273  * we are going to reuse the existing object data as is.  make
 274  * sure it is not corrupt.
 275  */
 276 static int check_inflate(unsigned char *data, unsigned long len, unsigned long expect)
 277 {
 278         z_stream stream;
 279         unsigned char fakebuf[4096];
 280         int st;
 281
 282         memset(&stream, 0, sizeof(stream));
 283         stream.next_in = data;
 284         stream.avail_in = len;
 285         stream.next_out = fakebuf;
 286         stream.avail_out = sizeof(fakebuf);
 287         inflateInit(&stream);
 288
 289         while (1) {
 290                 st = inflate(&stream, Z_FINISH);
 291                 if (st == Z_STREAM_END || st == Z_OK) {
 292                         st = (stream.total_out == expect &&
 293                               stream.total_in == len) ? 0 : -1;
 294                         break;
 295                 }
 296                 if (st != Z_BUF_ERROR) {
 297                         st = -1;
 298                         break;
 299                 }
 300                 stream.next_out = fakebuf;
 301                 stream.avail_out = sizeof(fakebuf);
 302         }
 303         inflateEnd(&stream);
 304         return st;
 305 }
 306
 307 static int revalidate_loose_object(struct object_entry *entry,
 308                                    unsigned char *map,
 309                                    unsigned long mapsize)
 310 {
 311         /* we already know this is a loose object with new type header. */
 312         enum object_type type;
 313         unsigned long size, used;
 314
 315         if (pack_to_stdout)
 316                 return 0;
 317
 318         used = unpack_object_header_gently(map, mapsize, &type, &size);
 319         if (!used)
 320                 return -1;
 321         map += used;
 322         mapsize -= used;
 323         return check_inflate(map, mapsize, size);
 324 }
 325
 326 static unsigned long write_object(struct sha1file *f,
 327                                   struct object_entry *entry)
 328 {
 329         unsigned long size;
 330         char type[10];
 331         void *buf;
 332         unsigned char header[10];
 333         unsigned hdrlen, datalen;
 334         enum object_type obj_type;
 335         int to_reuse = 0;
 336
 337         obj_type = entry->type;
 338         if (! entry->in_pack)
 339                 to_reuse = 0;   /* can't reuse what we don't have */
 340         else if (obj_type == OBJ_REF_DELTA || obj_type == OBJ_OFS_DELTA)
 341                 to_reuse = 1;   /* check_object() decided it for us */
 342         else if (obj_type != entry->in_pack_type)
 343                 to_reuse = 0;   /* pack has delta which is unusable */
 344         else if (entry->delta)
 345                 to_reuse = 0;   /* we want to pack afresh */
 346         else
 347                 to_reuse = 1;   /* we have it in-pack undeltified,
 348                                  * and we do not need to deltify it.
 349                                  */
 350
 351         if (!entry->in_pack && !entry->delta) {
 352                 unsigned char *map;
 353                 unsigned long mapsize;
 354                 map = map_sha1_file(entry->sha1, &mapsize);
 355                 if (map && !legacy_loose_object(map)) {
 356                         /* We can copy straight into the pack file */
 357                         if (revalidate_loose_object(entry, map, mapsize))
 358                                 die("corrupt loose object %s",
 359                                     sha1_to_hex(entry->sha1));
 360                         sha1write(f, map, mapsize);
 361                         munmap(map, mapsize);
 362                         written++;
 363                         reused++;
 364                         return mapsize;
 365                 }
 366                 if (map)
 367                         munmap(map, mapsize);
 368         }
 369
 370         if (!to_reuse) {
 371                 buf = read_sha1_file(entry->sha1, type, &size);
 372                 if (!buf)
 373                         die("unable to read %s", sha1_to_hex(entry->sha1));
 374                 if (size != entry->size)
 375                         die("object %s size inconsistency (%lu vs %lu)",
 376                             sha1_to_hex(entry->sha1), size, entry->size);
 377                 if (entry->delta) {
 378                         buf = delta_against(buf, size, entry);
 379                         size = entry->delta_size;
 380                         obj_type = (allow_ofs_delta && entry->delta->offset) ?
 381                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 382                 }
 383                 /*
 384                  * The object header is a byte of 'type' followed by zero or
 385                  * more bytes of length.
 386                  */
 387                 hdrlen = encode_header(obj_type, size, header);
 388                 sha1write(f, header, hdrlen);
 389
 390                 if (obj_type == OBJ_OFS_DELTA) {
 391                         /*
 392                          * Deltas with relative base contain an additional
 393                          * encoding of the relative offset for the delta
 394                          * base from this object's position in the pack.
 395                          */
 396                         unsigned long ofs = entry->offset - entry->delta->offset;
 397                         unsigned pos = sizeof(header) - 1;
 398                         header[pos] = ofs & 127;
 399                         while (ofs >>= 7)
 400                                 header[--pos] = 128 | (--ofs & 127);
 401                         sha1write(f, header + pos, sizeof(header) - pos);
 402                         hdrlen += sizeof(header) - pos;
 403                 } else if (obj_type == OBJ_REF_DELTA) {
 404                         /*
 405                          * Deltas with a base reference contain
 406                          * an additional 20 bytes for the base sha1.
 407                          */
 408                         sha1write(f, entry->delta->sha1, 20);
 409                         hdrlen += 20;
 410                 }
 411                 datalen = sha1write_compressed(f, buf, size);
 412                 free(buf);
 413         }
 414         else {
 415                 struct packed_git *p = entry->in_pack;
 416
 417                 if (entry->delta) {
 418                         obj_type = (allow_ofs_delta && entry->delta->offset) ?
 419                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 420                         reused_delta++;
 421                 }
 422                 hdrlen = encode_header(obj_type, entry->size, header);
 423                 sha1write(f, header, hdrlen);
 424                 if (obj_type == OBJ_OFS_DELTA) {
 425                         unsigned long ofs = entry->offset - entry->delta->offset;
 426                         unsigned pos = sizeof(header) - 1;
 427                         header[pos] = ofs & 127;
 428                         while (ofs >>= 7)
 429                                 header[--pos] = 128 | (--ofs & 127);
 430                         sha1write(f, header + pos, sizeof(header) - pos);
 431                         hdrlen += sizeof(header) - pos;
 432                 } else if (obj_type == OBJ_REF_DELTA) {
 433                         sha1write(f, entry->delta->sha1, 20);
 434                         hdrlen += 20;
 435                 }
 436
 437                 use_packed_git(p);
 438                 buf = (char *) p->pack_base
 439                         + entry->in_pack_offset
 440                         + entry->in_pack_header_size;
 441                 datalen = find_packed_object_size(p, entry->in_pack_offset)
 442                                 - entry->in_pack_header_size;
 443                 if (!pack_to_stdout && check_inflate(buf, datalen, entry->size))
 444                         die("corrupt delta in pack %s", sha1_to_hex(entry->sha1));
 445                 sha1write(f, buf, datalen);
 446                 unuse_packed_git(p);
 447                 reused++;
 448         }
 449         if (entry->delta)
 450                 written_delta++;
 451         written++;
 452         return hdrlen + datalen;
 453 }
 454
 455 static unsigned long write_one(struct sha1file *f,
 456                                struct object_entry *e,
 457                                unsigned long offset)
 458 {
 459         if (e->offset || e->preferred_base)
 460                 /* offset starts from header size and cannot be zero
 461                  * if it is written already.
 462                  */
 463                 return offset;
 464         /* if we are deltified, write out its base object first. */
 465         if (e->delta)
 466                 offset = write_one(f, e->delta, offset);
 467         e->offset = offset;
 468         return offset + write_object(f, e);
 469 }
 470
 471 static void write_pack_file(void)
 472 {
 473         int i;
 474         struct sha1file *f;
 475         unsigned long offset;
 476         struct pack_header hdr;
 477         unsigned last_percent = 999;
 478         int do_progress = 0;
 479
 480         if (!base_name)
 481                 f = sha1fd(1, "<stdout>");
 482         else {
 483                 f = sha1create("%s-%s.%s", base_name,
 484                                sha1_to_hex(object_list_sha1), "pack");
 485                 do_progress = progress;
 486         }
 487         if (do_progress)
 488                 fprintf(stderr, "Writing %d objects.\n", nr_result);
 489
 490         hdr.hdr_signature = htonl(PACK_SIGNATURE);
 491         hdr.hdr_version = htonl(PACK_VERSION);
 492         hdr.hdr_entries = htonl(nr_result);
 493         sha1write(f, &hdr, sizeof(hdr));
 494         offset = sizeof(hdr);
 495         if (!nr_result)
 496                 goto done;
 497         for (i = 0; i < nr_objects; i++) {
 498                 offset = write_one(f, objects + i, offset);
 499                 if (do_progress) {
 500                         unsigned percent = written * 100 / nr_result;
 501                         if (progress_update || percent != last_percent) {
 502                                 fprintf(stderr, "%4u%% (%u/%u) done\r",
 503                                         percent, written, nr_result);
 504                                 progress_update = 0;
 505                                 last_percent = percent;
 506                         }
 507                 }
 508         }
 509         if (do_progress)
 510                 fputc('\n', stderr);
 511  done:
 512         sha1close(f, pack_file_sha1, 1);
 513 }
 514
 515 static void write_index_file(void)
 516 {
 517         int i;
 518         struct sha1file *f = sha1create("%s-%s.%s", base_name,
 519                                         sha1_to_hex(object_list_sha1), "idx");
 520         struct object_entry **list = sorted_by_sha;
 521         struct object_entry **last = list + nr_result;
 522         unsigned int array[256];
 523
 524         /*
 525          * Write the first-level table (the list is sorted,
 526          * but we use a 256-entry lookup to be able to avoid
 527          * having to do eight extra binary search iterations).
 528          */
 529         for (i = 0; i < 256; i++) {
 530                 struct object_entry **next = list;
 531                 while (next < last) {
 532                         struct object_entry *entry = *next;
 533                         if (entry->sha1[0] != i)
 534                                 break;
 535                         next++;
 536                 }
 537                 array[i] = htonl(next - sorted_by_sha);
 538                 list = next;
 539         }
 540         sha1write(f, array, 256 * sizeof(int));
 541
 542         /*
 543          * Write the actual SHA1 entries..
 544          */
 545         list = sorted_by_sha;
 546         for (i = 0; i < nr_result; i++) {
 547                 struct object_entry *entry = *list++;
 548                 unsigned int offset = htonl(entry->offset);
 549                 sha1write(f, &offset, 4);
 550                 sha1write(f, entry->sha1, 20);
 551         }
 552         sha1write(f, pack_file_sha1, 20);
 553         sha1close(f, NULL, 1);
 554 }
 555
 556 static int locate_object_entry_hash(const unsigned char *sha1)
 557 {
 558         int i;
 559         unsigned int ui;
 560         memcpy(&ui, sha1, sizeof(unsigned int));
 561         i = ui % object_ix_hashsz;
 562         while (0 < object_ix[i]) {
 563                 if (!hashcmp(sha1, objects[object_ix[i] - 1].sha1))
 564                         return i;
 565                 if (++i == object_ix_hashsz)
 566                         i = 0;
 567         }
 568         return -1 - i;
 569 }
 570
 571 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 572 {
 573         int i;
 574
 575         if (!object_ix_hashsz)
 576                 return NULL;
 577
 578         i = locate_object_entry_hash(sha1);
 579         if (0 <= i)
 580                 return &objects[object_ix[i]-1];
 581         return NULL;
 582 }
 583
 584 static void rehash_objects(void)
 585 {
 586         int i;
 587         struct object_entry *oe;
 588
 589         object_ix_hashsz = nr_objects * 3;
 590         if (object_ix_hashsz < 1024)
 591                 object_ix_hashsz = 1024;
 592         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 593         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 594         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 595                 int ix = locate_object_entry_hash(oe->sha1);
 596                 if (0 <= ix)
 597                         continue;
 598                 ix = -1 - ix;
 599                 object_ix[ix] = i + 1;
 600         }
 601 }
 602
 603 static unsigned name_hash(const char *name)
 604 {
 605         unsigned char c;
 606         unsigned hash = 0;
 607
 608         /*
 609          * This effectively just creates a sortable number from the
 610          * last sixteen non-whitespace characters. Last characters
 611          * count "most", so things that end in ".c" sort together.
 612          */
 613         while ((c = *name++) != 0) {
 614                 if (isspace(c))
 615                         continue;
 616                 hash = (hash >> 2) + (c << 24);
 617         }
 618         return hash;
 619 }
 620
 621 static int add_object_entry(const unsigned char *sha1, unsigned hash, int exclude)
 622 {
 623         unsigned int idx = nr_objects;
 624         struct object_entry *entry;
 625         struct packed_git *p;
 626         unsigned int found_offset = 0;
 627         struct packed_git *found_pack = NULL;
 628         int ix, status = 0;
 629
 630         if (!exclude) {
 631                 for (p = packed_git; p; p = p->next) {
 632                         unsigned long offset = find_pack_entry_one(sha1, p);
 633                         if (offset) {
 634                                 if (incremental)
 635                                         return 0;
 636                                 if (local && !p->pack_local)
 637                                         return 0;
 638                                 if (!found_pack) {
 639                                         found_offset = offset;
 640                                         found_pack = p;
 641                                 }
 642                         }
 643                 }
 644         }
 645         if ((entry = locate_object_entry(sha1)) != NULL)
 646                 goto already_added;
 647
 648         if (idx >= nr_alloc) {
 649                 unsigned int needed = (idx + 1024) * 3 / 2;
 650                 objects = xrealloc(objects, needed * sizeof(*entry));
 651                 nr_alloc = needed;
 652         }
 653         entry = objects + idx;
 654         nr_objects = idx + 1;
 655         memset(entry, 0, sizeof(*entry));
 656         hashcpy(entry->sha1, sha1);
 657         entry->hash = hash;
 658
 659         if (object_ix_hashsz * 3 <= nr_objects * 4)
 660                 rehash_objects();
 661         else {
 662                 ix = locate_object_entry_hash(entry->sha1);
 663                 if (0 <= ix)
 664                         die("internal error in object hashing.");
 665                 object_ix[-1 - ix] = idx + 1;
 666         }
 667         status = 1;
 668
 669  already_added:
 670         if (progress_update) {
 671                 fprintf(stderr, "Counting objects...%d\r", nr_objects);
 672                 progress_update = 0;
 673         }
 674         if (exclude)
 675                 entry->preferred_base = 1;
 676         else {
 677                 if (found_pack) {
 678                         entry->in_pack = found_pack;
 679                         entry->in_pack_offset = found_offset;
 680                 }
 681         }
 682         return status;
 683 }
 684
 685 struct pbase_tree_cache {
 686         unsigned char sha1[20];
 687         int ref;
 688         int temporary;
 689         void *tree_data;
 690         unsigned long tree_size;
 691 };
 692
 693 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 694 static int pbase_tree_cache_ix(const unsigned char *sha1)
 695 {
 696         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 697 }
 698 static int pbase_tree_cache_ix_incr(int ix)
 699 {
 700         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 701 }
 702
 703 static struct pbase_tree {
 704         struct pbase_tree *next;
 705         /* This is a phony "cache" entry; we are not
 706          * going to evict it nor find it through _get()
 707          * mechanism -- this is for the toplevel node that
 708          * would almost always change with any commit.
 709          */
 710         struct pbase_tree_cache pcache;
 711 } *pbase_tree;
 712
 713 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 714 {
 715         struct pbase_tree_cache *ent, *nent;
 716         void *data;
 717         unsigned long size;
 718         char type[20];
 719         int neigh;
 720         int my_ix = pbase_tree_cache_ix(sha1);
 721         int available_ix = -1;
 722
 723         /* pbase-tree-cache acts as a limited hashtable.
 724          * your object will be found at your index or within a few
 725          * slots after that slot if it is cached.
 726          */
 727         for (neigh = 0; neigh < 8; neigh++) {
 728                 ent = pbase_tree_cache[my_ix];
 729                 if (ent && !hashcmp(ent->sha1, sha1)) {
 730                         ent->ref++;
 731                         return ent;
 732                 }
 733                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 734                          ((0 <= available_ix) &&
 735                           (!ent && pbase_tree_cache[available_ix])))
 736                         available_ix = my_ix;
 737                 if (!ent)
 738                         break;
 739                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 740         }
 741
 742         /* Did not find one.  Either we got a bogus request or
 743          * we need to read and perhaps cache.
 744          */
 745         data = read_sha1_file(sha1, type, &size);
 746         if (!data)
 747                 return NULL;
 748         if (strcmp(type, tree_type)) {
 749                 free(data);
 750                 return NULL;
 751         }
 752
 753         /* We need to either cache or return a throwaway copy */
 754
 755         if (available_ix < 0)
 756                 ent = NULL;
 757         else {
 758                 ent = pbase_tree_cache[available_ix];
 759                 my_ix = available_ix;
 760         }
 761
 762         if (!ent) {
 763                 nent = xmalloc(sizeof(*nent));
 764                 nent->temporary = (available_ix < 0);
 765         }
 766         else {
 767                 /* evict and reuse */
 768                 free(ent->tree_data);
 769                 nent = ent;
 770         }
 771         hashcpy(nent->sha1, sha1);
 772         nent->tree_data = data;
 773         nent->tree_size = size;
 774         nent->ref = 1;
 775         if (!nent->temporary)
 776                 pbase_tree_cache[my_ix] = nent;
 777         return nent;
 778 }
 779
 780 static void pbase_tree_put(struct pbase_tree_cache *cache)
 781 {
 782         if (!cache->temporary) {
 783                 cache->ref--;
 784                 return;
 785         }
 786         free(cache->tree_data);
 787         free(cache);
 788 }
 789
 790 static int name_cmp_len(const char *name)
 791 {
 792         int i;
 793         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 794                 ;
 795         return i;
 796 }
 797
 798 static void add_pbase_object(struct tree_desc *tree,
 799                              const char *name,
 800                              int cmplen,
 801                              const char *fullname)
 802 {
 803         struct name_entry entry;
 804
 805         while (tree_entry(tree,&entry)) {
 806                 unsigned long size;
 807                 char type[20];
 808
 809                 if (entry.pathlen != cmplen ||
 810                     memcmp(entry.path, name, cmplen) ||
 811                     !has_sha1_file(entry.sha1) ||
 812                     sha1_object_info(entry.sha1, type, &size))
 813                         continue;
 814                 if (name[cmplen] != '/') {
 815                         unsigned hash = name_hash(fullname);
 816                         add_object_entry(entry.sha1, hash, 1);
 817                         return;
 818                 }
 819                 if (!strcmp(type, tree_type)) {
 820                         struct tree_desc sub;
 821                         struct pbase_tree_cache *tree;
 822                         const char *down = name+cmplen+1;
 823                         int downlen = name_cmp_len(down);
 824
 825                         tree = pbase_tree_get(entry.sha1);
 826                         if (!tree)
 827                                 return;
 828                         sub.buf = tree->tree_data;
 829                         sub.size = tree->tree_size;
 830
 831                         add_pbase_object(&sub, down, downlen, fullname);
 832                         pbase_tree_put(tree);
 833                 }
 834         }
 835 }
 836
 837 static unsigned *done_pbase_paths;
 838 static int done_pbase_paths_num;
 839 static int done_pbase_paths_alloc;
 840 static int done_pbase_path_pos(unsigned hash)
 841 {
 842         int lo = 0;
 843         int hi = done_pbase_paths_num;
 844         while (lo < hi) {
 845                 int mi = (hi + lo) / 2;
 846                 if (done_pbase_paths[mi] == hash)
 847                         return mi;
 848                 if (done_pbase_paths[mi] < hash)
 849                         hi = mi;
 850                 else
 851                         lo = mi + 1;
 852         }
 853         return -lo-1;
 854 }
 855
 856 static int check_pbase_path(unsigned hash)
 857 {
 858         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 859         if (0 <= pos)
 860                 return 1;
 861         pos = -pos - 1;
 862         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 863                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 864                 done_pbase_paths = xrealloc(done_pbase_paths,
 865                                             done_pbase_paths_alloc *
 866                                             sizeof(unsigned));
 867         }
 868         done_pbase_paths_num++;
 869         if (pos < done_pbase_paths_num)
 870                 memmove(done_pbase_paths + pos + 1,
 871                         done_pbase_paths + pos,
 872                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 873         done_pbase_paths[pos] = hash;
 874         return 0;
 875 }
 876
 877 static void add_preferred_base_object(const char *name, unsigned hash)
 878 {
 879         struct pbase_tree *it;
 880         int cmplen = name_cmp_len(name);
 881
 882         if (check_pbase_path(hash))
 883                 return;
 884
 885         for (it = pbase_tree; it; it = it->next) {
 886                 if (cmplen == 0) {
 887                         hash = name_hash("");
 888                         add_object_entry(it->pcache.sha1, hash, 1);
 889                 }
 890                 else {
 891                         struct tree_desc tree;
 892                         tree.buf = it->pcache.tree_data;
 893                         tree.size = it->pcache.tree_size;
 894                         add_pbase_object(&tree, name, cmplen, name);
 895                 }
 896         }
 897 }
 898
 899 static void add_preferred_base(unsigned char *sha1)
 900 {
 901         struct pbase_tree *it;
 902         void *data;
 903         unsigned long size;
 904         unsigned char tree_sha1[20];
 905
 906         if (window <= num_preferred_base++)
 907                 return;
 908
 909         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 910         if (!data)
 911                 return;
 912
 913         for (it = pbase_tree; it; it = it->next) {
 914                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 915                         free(data);
 916                         return;
 917                 }
 918         }
 919
 920         it = xcalloc(1, sizeof(*it));
 921         it->next = pbase_tree;
 922         pbase_tree = it;
 923
 924         hashcpy(it->pcache.sha1, tree_sha1);
 925         it->pcache.tree_data = data;
 926         it->pcache.tree_size = size;
 927 }
 928
 929 static void check_object(struct object_entry *entry)
 930 {
 931         char type[20];
 932
 933         if (entry->in_pack && !entry->preferred_base) {
 934                 struct packed_git *p = entry->in_pack;
 935                 unsigned long left = p->pack_size - entry->in_pack_offset;
 936                 unsigned long size, used;
 937                 unsigned char *buf;
 938                 struct object_entry *base_entry = NULL;
 939
 940                 use_packed_git(p);
 941                 buf = p->pack_base;
 942                 buf += entry->in_pack_offset;
 943
 944                 /* We want in_pack_type even if we do not reuse delta.
 945                  * There is no point not reusing non-delta representations.
 946                  */
 947                 used = unpack_object_header_gently(buf, left,
 948                                                    &entry->in_pack_type, &size);
 949                 if (!used || left - used <= 20)
 950                         die("corrupt pack for %s", sha1_to_hex(entry->sha1));
 951
 952                 /* Check if it is delta, and the base is also an object
 953                  * we are going to pack.  If so we will reuse the existing
 954                  * delta.
 955                  */
 956                 if (!no_reuse_delta) {
 957                         unsigned char c, *base_name;
 958                         unsigned long ofs;
 959                         /* there is at least 20 bytes left in the pack */
 960                         switch (entry->in_pack_type) {
 961                         case OBJ_REF_DELTA:
 962                                 base_name = buf + used;
 963                                 used += 20;
 964                                 break;
 965                         case OBJ_OFS_DELTA:
 966                                 c = buf[used++];
 967                                 ofs = c & 127;
 968                                 while (c & 128) {
 969                                         ofs += 1;
 970                                         if (!ofs || ofs & ~(~0UL >> 7))
 971                                                 die("delta base offset overflow in pack for %s",
 972                                                     sha1_to_hex(entry->sha1));
 973                                         c = buf[used++];
 974                                         ofs = (ofs << 7) + (c & 127);
 975                                 }
 976                                 if (ofs >= entry->in_pack_offset)
 977                                         die("delta base offset out of bound for %s",
 978                                             sha1_to_hex(entry->sha1));
 979                                 ofs = entry->in_pack_offset - ofs;
 980                                 base_name = find_packed_object_name(p, ofs);
 981                                 break;
 982                         default:
 983                                 base_name = NULL;
 984                         }
 985                         if (base_name)
 986                                 base_entry = locate_object_entry(base_name);
 987                 }
 988                 unuse_packed_git(p);
 989                 entry->in_pack_header_size = used;
 990
 991                 if (base_entry) {
 992
 993                         /* Depth value does not matter - find_deltas()
 994                          * will never consider reused delta as the
 995                          * base object to deltify other objects
 996                          * against, in order to avoid circular deltas.
 997                          */
 998
 999                         /* uncompressed size of the delta data */
1000                         entry->size = size;
1001                         entry->delta = base_entry;
1002                         entry->type = entry->in_pack_type;
1003
1004                         entry->delta_sibling = base_entry->delta_child;
1005                         base_entry->delta_child = entry;
1006
1007                         return;
1008                 }
1009                 /* Otherwise we would do the usual */
1010         }
1011
1012         if (sha1_object_info(entry->sha1, type, &entry->size))
1013                 die("unable to get type of object %s",
1014                     sha1_to_hex(entry->sha1));
1015
1016         if (!strcmp(type, commit_type)) {
1017                 entry->type = OBJ_COMMIT;
1018         } else if (!strcmp(type, tree_type)) {
1019                 entry->type = OBJ_TREE;
1020         } else if (!strcmp(type, blob_type)) {
1021                 entry->type = OBJ_BLOB;
1022         } else if (!strcmp(type, tag_type)) {
1023                 entry->type = OBJ_TAG;
1024         } else
1025                 die("unable to pack object %s of type %s",
1026                     sha1_to_hex(entry->sha1), type);
1027 }
1028
1029 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1030 {
1031         struct object_entry *child = me->delta_child;
1032         unsigned int m = n;
1033         while (child) {
1034                 unsigned int c = check_delta_limit(child, n + 1);
1035                 if (m < c)
1036                         m = c;
1037                 child = child->delta_sibling;
1038         }
1039         return m;
1040 }
1041
1042 static void get_object_details(void)
1043 {
1044         int i;
1045         struct object_entry *entry;
1046
1047         prepare_pack_ix();
1048         for (i = 0, entry = objects; i < nr_objects; i++, entry++)
1049                 check_object(entry);
1050
1051         if (nr_objects == nr_result) {
1052                 /*
1053                  * Depth of objects that depend on the entry -- this
1054                  * is subtracted from depth-max to break too deep
1055                  * delta chain because of delta data reusing.
1056                  * However, we loosen this restriction when we know we
1057                  * are creating a thin pack -- it will have to be
1058                  * expanded on the other end anyway, so do not
1059                  * artificially cut the delta chain and let it go as
1060                  * deep as it wants.
1061                  */
1062                 for (i = 0, entry = objects; i < nr_objects; i++, entry++)
1063                         if (!entry->delta && entry->delta_child)
1064                                 entry->delta_limit =
1065                                         check_delta_limit(entry, 1);
1066         }
1067 }
1068
1069 typedef int (*entry_sort_t)(const struct object_entry *, const struct object_entry *);
1070
1071 static entry_sort_t current_sort;
1072
1073 static int sort_comparator(const void *_a, const void *_b)
1074 {
1075         struct object_entry *a = *(struct object_entry **)_a;
1076         struct object_entry *b = *(struct object_entry **)_b;
1077         return current_sort(a,b);
1078 }
1079
1080 static struct object_entry **create_sorted_list(entry_sort_t sort)
1081 {
1082         struct object_entry **list = xmalloc(nr_objects * sizeof(struct object_entry *));
1083         int i;
1084
1085         for (i = 0; i < nr_objects; i++)
1086                 list[i] = objects + i;
1087         current_sort = sort;
1088         qsort(list, nr_objects, sizeof(struct object_entry *), sort_comparator);
1089         return list;
1090 }
1091
1092 static int sha1_sort(const struct object_entry *a, const struct object_entry *b)
1093 {
1094         return hashcmp(a->sha1, b->sha1);
1095 }
1096
1097 static struct object_entry **create_final_object_list(void)
1098 {
1099         struct object_entry **list;
1100         int i, j;
1101
1102         for (i = nr_result = 0; i < nr_objects; i++)
1103                 if (!objects[i].preferred_base)
1104                         nr_result++;
1105         list = xmalloc(nr_result * sizeof(struct object_entry *));
1106         for (i = j = 0; i < nr_objects; i++) {
1107                 if (!objects[i].preferred_base)
1108                         list[j++] = objects + i;
1109         }
1110         current_sort = sha1_sort;
1111         qsort(list, nr_result, sizeof(struct object_entry *), sort_comparator);
1112         return list;
1113 }
1114
1115 static int type_size_sort(const struct object_entry *a, const struct object_entry *b)
1116 {
1117         if (a->type < b->type)
1118                 return -1;
1119         if (a->type > b->type)
1120                 return 1;
1121         if (a->hash < b->hash)
1122                 return -1;
1123         if (a->hash > b->hash)
1124                 return 1;
1125         if (a->preferred_base < b->preferred_base)
1126                 return -1;
1127         if (a->preferred_base > b->preferred_base)
1128                 return 1;
1129         if (a->size < b->size)
1130                 return -1;
1131         if (a->size > b->size)
1132                 return 1;
1133         return a < b ? -1 : (a > b);
1134 }
1135
1136 struct unpacked {
1137         struct object_entry *entry;
1138         void *data;
1139         struct delta_index *index;
1140 };
1141
1142 /*
1143  * We search for deltas _backwards_ in a list sorted by type and
1144  * by size, so that we see progressively smaller and smaller files.
1145  * That's because we prefer deltas to be from the bigger file
1146  * to the smaller - deletes are potentially cheaper, but perhaps
1147  * more importantly, the bigger file is likely the more recent
1148  * one.
1149  */
1150 static int try_delta(struct unpacked *trg, struct unpacked *src,
1151                      unsigned max_depth)
1152 {
1153         struct object_entry *trg_entry = trg->entry;
1154         struct object_entry *src_entry = src->entry;
1155         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1156         char type[10];
1157         void *delta_buf;
1158
1159         /* Don't bother doing diffs between different types */
1160         if (trg_entry->type != src_entry->type)
1161                 return -1;
1162
1163         /* We do not compute delta to *create* objects we are not
1164          * going to pack.
1165          */
1166         if (trg_entry->preferred_base)
1167                 return -1;
1168
1169         /*
1170          * We do not bother to try a delta that we discarded
1171          * on an earlier try, but only when reusing delta data.
1172          */
1173         if (!no_reuse_delta && trg_entry->in_pack &&
1174             trg_entry->in_pack == src_entry->in_pack)
1175                 return 0;
1176
1177         /*
1178          * If the current object is at pack edge, take the depth the
1179          * objects that depend on the current object into account --
1180          * otherwise they would become too deep.
1181          */
1182         if (trg_entry->delta_child) {
1183                 if (max_depth <= trg_entry->delta_limit)
1184                         return 0;
1185                 max_depth -= trg_entry->delta_limit;
1186         }
1187         if (src_entry->depth >= max_depth)
1188                 return 0;
1189
1190         /* Now some size filtering heuristics. */
1191         trg_size = trg_entry->size;
1192         max_size = trg_size/2 - 20;
1193         max_size = max_size * (max_depth - src_entry->depth) / max_depth;
1194         if (max_size == 0)
1195                 return 0;
1196         if (trg_entry->delta && trg_entry->delta_size <= max_size)
1197                 max_size = trg_entry->delta_size-1;
1198         src_size = src_entry->size;
1199         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1200         if (sizediff >= max_size)
1201                 return 0;
1202
1203         /* Load data if not already done */
1204         if (!trg->data) {
1205                 trg->data = read_sha1_file(trg_entry->sha1, type, &sz);
1206                 if (sz != trg_size)
1207                         die("object %s inconsistent object length (%lu vs %lu)",
1208                             sha1_to_hex(trg_entry->sha1), sz, trg_size);
1209         }
1210         if (!src->data) {
1211                 src->data = read_sha1_file(src_entry->sha1, type, &sz);
1212                 if (sz != src_size)
1213                         die("object %s inconsistent object length (%lu vs %lu)",
1214                             sha1_to_hex(src_entry->sha1), sz, src_size);
1215         }
1216         if (!src->index) {
1217                 src->index = create_delta_index(src->data, src_size);
1218                 if (!src->index)
1219                         die("out of memory");
1220         }
1221
1222         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1223         if (!delta_buf)
1224                 return 0;
1225
1226         trg_entry->delta = src_entry;
1227         trg_entry->delta_size = delta_size;
1228         trg_entry->depth = src_entry->depth + 1;
1229         free(delta_buf);
1230         return 1;
1231 }
1232
1233 static void progress_interval(int signum)
1234 {
1235         progress_update = 1;
1236 }
1237
1238 static void find_deltas(struct object_entry **list, int window, int depth)
1239 {
1240         int i, idx;
1241         unsigned int array_size = window * sizeof(struct unpacked);
1242         struct unpacked *array = xmalloc(array_size);
1243         unsigned processed = 0;
1244         unsigned last_percent = 999;
1245
1246         memset(array, 0, array_size);
1247         i = nr_objects;
1248         idx = 0;
1249         if (progress)
1250                 fprintf(stderr, "Deltifying %d objects.\n", nr_result);
1251
1252         while (--i >= 0) {
1253                 struct object_entry *entry = list[i];
1254                 struct unpacked *n = array + idx;
1255                 int j;
1256
1257                 if (!entry->preferred_base)
1258                         processed++;
1259
1260                 if (progress) {
1261                         unsigned percent = processed * 100 / nr_result;
1262                         if (percent != last_percent || progress_update) {
1263                                 fprintf(stderr, "%4u%% (%u/%u) done\r",
1264                                         percent, processed, nr_result);
1265                                 progress_update = 0;
1266                                 last_percent = percent;
1267                         }
1268                 }
1269
1270                 if (entry->delta)
1271                         /* This happens if we decided to reuse existing
1272                          * delta from a pack.  "!no_reuse_delta &&" is implied.
1273                          */
1274                         continue;
1275
1276                 if (entry->size < 50)
1277                         continue;
1278                 free_delta_index(n->index);
1279                 n->index = NULL;
1280                 free(n->data);
1281                 n->data = NULL;
1282                 n->entry = entry;
1283
1284                 j = window;
1285                 while (--j > 0) {
1286                         unsigned int other_idx = idx + j;
1287                         struct unpacked *m;
1288                         if (other_idx >= window)
1289                                 other_idx -= window;
1290                         m = array + other_idx;
1291                         if (!m->entry)
1292                                 break;
1293                         if (try_delta(n, m, depth) < 0)
1294                                 break;
1295                 }
1296                 /* if we made n a delta, and if n is already at max
1297                  * depth, leaving it in the window is pointless.  we
1298                  * should evict it first.
1299                  */
1300                 if (entry->delta && depth <= entry->depth)
1301                         continue;
1302
1303                 idx++;
1304                 if (idx >= window)
1305                         idx = 0;
1306         }
1307
1308         if (progress)
1309                 fputc('\n', stderr);
1310
1311         for (i = 0; i < window; ++i) {
1312                 free_delta_index(array[i].index);
1313                 free(array[i].data);
1314         }
1315         free(array);
1316 }
1317
1318 static void prepare_pack(int window, int depth)
1319 {
1320         get_object_details();
1321         sorted_by_type = create_sorted_list(type_size_sort);
1322         if (window && depth)
1323                 find_deltas(sorted_by_type, window+1, depth);
1324 }
1325
1326 static int reuse_cached_pack(unsigned char *sha1)
1327 {
1328         static const char cache[] = "pack-cache/pack-%s.%s";
1329         char *cached_pack, *cached_idx;
1330         int ifd, ofd, ifd_ix = -1;
1331
1332         cached_pack = git_path(cache, sha1_to_hex(sha1), "pack");
1333         ifd = open(cached_pack, O_RDONLY);
1334         if (ifd < 0)
1335                 return 0;
1336
1337         if (!pack_to_stdout) {
1338                 cached_idx = git_path(cache, sha1_to_hex(sha1), "idx");
1339                 ifd_ix = open(cached_idx, O_RDONLY);
1340                 if (ifd_ix < 0) {
1341                         close(ifd);
1342                         return 0;
1343                 }
1344         }
1345
1346         if (progress)
1347                 fprintf(stderr, "Reusing %d objects pack %s\n", nr_objects,
1348                         sha1_to_hex(sha1));
1349
1350         if (pack_to_stdout) {
1351                 if (copy_fd(ifd, 1))
1352                         exit(1);
1353                 close(ifd);
1354         }
1355         else {
1356                 char name[PATH_MAX];
1357                 snprintf(name, sizeof(name),
1358                          "%s-%s.%s", base_name, sha1_to_hex(sha1), "pack");
1359                 ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
1360                 if (ofd < 0)
1361                         die("unable to open %s (%s)", name, strerror(errno));
1362                 if (copy_fd(ifd, ofd))
1363                         exit(1);
1364                 close(ifd);
1365
1366                 snprintf(name, sizeof(name),
1367                          "%s-%s.%s", base_name, sha1_to_hex(sha1), "idx");
1368                 ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
1369                 if (ofd < 0)
1370                         die("unable to open %s (%s)", name, strerror(errno));
1371                 if (copy_fd(ifd_ix, ofd))
1372                         exit(1);
1373                 close(ifd_ix);
1374                 puts(sha1_to_hex(sha1));
1375         }
1376
1377         return 1;
1378 }
1379
1380 static void setup_progress_signal(void)
1381 {
1382         struct sigaction sa;
1383         struct itimerval v;
1384
1385         memset(&sa, 0, sizeof(sa));
1386         sa.sa_handler = progress_interval;
1387         sigemptyset(&sa.sa_mask);
1388         sa.sa_flags = SA_RESTART;
1389         sigaction(SIGALRM, &sa, NULL);
1390
1391         v.it_interval.tv_sec = 1;
1392         v.it_interval.tv_usec = 0;
1393         v.it_value = v.it_interval;
1394         setitimer(ITIMER_REAL, &v, NULL);
1395 }
1396
1397 static int git_pack_config(const char *k, const char *v)
1398 {
1399         if(!strcmp(k, "pack.window")) {
1400                 window = git_config_int(k, v);
1401                 return 0;
1402         }
1403         return git_default_config(k, v);
1404 }
1405
1406 static void read_object_list_from_stdin(void)
1407 {
1408         char line[40 + 1 + PATH_MAX + 2];
1409         unsigned char sha1[20];
1410         unsigned hash;
1411
1412         for (;;) {
1413                 if (!fgets(line, sizeof(line), stdin)) {
1414                         if (feof(stdin))
1415                                 break;
1416                         if (!ferror(stdin))
1417                                 die("fgets returned NULL, not EOF, not error!");
1418                         if (errno != EINTR)
1419                                 die("fgets: %s", strerror(errno));
1420                         clearerr(stdin);
1421                         continue;
1422                 }
1423                 if (line[0] == '-') {
1424                         if (get_sha1_hex(line+1, sha1))
1425                                 die("expected edge sha1, got garbage:\n %s",
1426                                     line);
1427                         add_preferred_base(sha1);
1428                         continue;
1429                 }
1430                 if (get_sha1_hex(line, sha1))
1431                         die("expected sha1, got garbage:\n %s", line);
1432
1433                 hash = name_hash(line+41);
1434                 add_preferred_base_object(line+41, hash);
1435                 add_object_entry(sha1, hash, 0);
1436         }
1437 }
1438
1439 static void show_commit(struct commit *commit)
1440 {
1441         unsigned hash = name_hash("");
1442         add_preferred_base_object("", hash);
1443         add_object_entry(commit->object.sha1, hash, 0);
1444 }
1445
1446 static void show_object(struct object_array_entry *p)
1447 {
1448         unsigned hash = name_hash(p->name);
1449         add_preferred_base_object(p->name, hash);
1450         add_object_entry(p->item->sha1, hash, 0);
1451 }
1452
1453 static void show_edge(struct commit *commit)
1454 {
1455         add_preferred_base(commit->object.sha1);
1456 }
1457
1458 static void get_object_list(int ac, const char **av)
1459 {
1460         struct rev_info revs;
1461         char line[1000];
1462         int flags = 0;
1463
1464         init_revisions(&revs, NULL);
1465         save_commit_buffer = 0;
1466         track_object_refs = 0;
1467         setup_revisions(ac, av, &revs, NULL);
1468
1469         while (fgets(line, sizeof(line), stdin) != NULL) {
1470                 int len = strlen(line);
1471                 if (line[len - 1] == '\n')
1472                         line[--len] = 0;
1473                 if (!len)
1474                         break;
1475                 if (*line == '-') {
1476                         if (!strcmp(line, "--not")) {
1477                                 flags ^= UNINTERESTING;
1478                                 continue;
1479                         }
1480                         die("not a rev '%s'", line);
1481                 }
1482                 if (handle_revision_arg(line, &revs, flags, 1))
1483                         die("bad revision '%s'", line);
1484         }
1485
1486         prepare_revision_walk(&revs);
1487         mark_edges_uninteresting(revs.commits, &revs, show_edge);
1488         traverse_commit_list(&revs, show_commit, show_object);
1489 }
1490
1491 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
1492 {
1493         SHA_CTX ctx;
1494         int depth = 10;
1495         struct object_entry **list;
1496         int use_internal_rev_list = 0;
1497         int thin = 0;
1498         int i;
1499         const char *rp_av[64];
1500         int rp_ac;
1501
1502         rp_av[0] = "pack-objects";
1503         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
1504         rp_ac = 2;
1505
1506         git_config(git_pack_config);
1507
1508         progress = isatty(2);
1509         for (i = 1; i < argc; i++) {
1510                 const char *arg = argv[i];
1511
1512                 if (*arg != '-')
1513                         break;
1514
1515                 if (!strcmp("--non-empty", arg)) {
1516                         non_empty = 1;
1517                         continue;
1518                 }
1519                 if (!strcmp("--local", arg)) {
1520                         local = 1;
1521                         continue;
1522                 }
1523                 if (!strcmp("--progress", arg)) {
1524                         progress = 1;
1525                         continue;
1526                 }
1527                 if (!strcmp("--incremental", arg)) {
1528                         incremental = 1;
1529                         continue;
1530                 }
1531                 if (!strncmp("--window=", arg, 9)) {
1532                         char *end;
1533                         window = strtoul(arg+9, &end, 0);
1534                         if (!arg[9] || *end)
1535                                 usage(pack_usage);
1536                         continue;
1537                 }
1538                 if (!strncmp("--depth=", arg, 8)) {
1539                         char *end;
1540                         depth = strtoul(arg+8, &end, 0);
1541                         if (!arg[8] || *end)
1542                                 usage(pack_usage);
1543                         continue;
1544                 }
1545                 if (!strcmp("--progress", arg)) {
1546                         progress = 1;
1547                         continue;
1548                 }
1549                 if (!strcmp("-q", arg)) {
1550                         progress = 0;
1551                         continue;
1552                 }
1553                 if (!strcmp("--no-reuse-delta", arg)) {
1554                         no_reuse_delta = 1;
1555                         continue;
1556                 }
1557                 if (!strcmp("--delta-base-offset", arg)) {
1558                         allow_ofs_delta = 1;
1559                         continue;
1560                 }
1561                 if (!strcmp("--stdout", arg)) {
1562                         pack_to_stdout = 1;
1563                         continue;
1564                 }
1565                 if (!strcmp("--revs", arg)) {
1566                         use_internal_rev_list = 1;
1567                         continue;
1568                 }
1569                 if (!strcmp("--unpacked", arg) ||
1570                     !strncmp("--unpacked=", arg, 11) ||
1571                     !strcmp("--all", arg)) {
1572                         use_internal_rev_list = 1;
1573                         if (ARRAY_SIZE(rp_av) - 1 <= rp_ac)
1574                                 die("too many internal rev-list options");
1575                         rp_av[rp_ac++] = arg;
1576                         continue;
1577                 }
1578                 if (!strcmp("--thin", arg)) {
1579                         use_internal_rev_list = 1;
1580                         thin = 1;
1581                         rp_av[1] = "--objects-edge";
1582                         continue;
1583                 }
1584                 usage(pack_usage);
1585         }
1586
1587         /* Traditionally "pack-objects [options] base extra" failed;
1588          * we would however want to take refs parameter that would
1589          * have been given to upstream rev-list ourselves, which means
1590          * we somehow want to say what the base name is.  So the
1591          * syntax would be:
1592          *
1593          * pack-objects [options] base <refs...>
1594          *
1595          * in other words, we would treat the first non-option as the
1596          * base_name and send everything else to the internal revision
1597          * walker.
1598          */
1599
1600         if (!pack_to_stdout)
1601                 base_name = argv[i++];
1602
1603         if (pack_to_stdout != !base_name)
1604                 usage(pack_usage);
1605
1606         if (!pack_to_stdout && thin)
1607                 die("--thin cannot be used to build an indexable pack.");
1608
1609         prepare_packed_git();
1610
1611         if (progress) {
1612                 fprintf(stderr, "Generating pack...\n");
1613                 setup_progress_signal();
1614         }
1615
1616         if (!use_internal_rev_list)
1617                 read_object_list_from_stdin();
1618         else {
1619                 rp_av[rp_ac] = NULL;
1620                 get_object_list(rp_ac, rp_av);
1621         }
1622
1623         if (progress)
1624                 fprintf(stderr, "Done counting %d objects.\n", nr_objects);
1625         sorted_by_sha = create_final_object_list();
1626         if (non_empty && !nr_result)
1627                 return 0;
1628
1629         SHA1_Init(&ctx);
1630         list = sorted_by_sha;
1631         for (i = 0; i < nr_result; i++) {
1632                 struct object_entry *entry = *list++;
1633                 SHA1_Update(&ctx, entry->sha1, 20);
1634         }
1635         SHA1_Final(object_list_sha1, &ctx);
1636         if (progress && (nr_objects != nr_result))
1637                 fprintf(stderr, "Result has %d objects.\n", nr_result);
1638
1639         if (reuse_cached_pack(object_list_sha1))
1640                 ;
1641         else {
1642                 if (nr_result)
1643                         prepare_pack(window, depth);
1644                 if (progress && pack_to_stdout) {
1645                         /* the other end usually displays progress itself */
1646                         struct itimerval v = {{0,},};
1647                         setitimer(ITIMER_REAL, &v, NULL);
1648                         signal(SIGALRM, SIG_IGN );
1649                         progress_update = 0;
1650                 }
1651                 write_pack_file();
1652                 if (!pack_to_stdout) {
1653                         write_index_file();
1654                         puts(sha1_to_hex(object_list_sha1));
1655                 }
1656         }
1657         if (progress)
1658                 fprintf(stderr, "Total %d, written %d (delta %d), reused %d (delta %d)\n",
1659                         nr_result, written, written_delta, reused, reused_delta);
1660         return 0;
1661 }