index-pack.c

   1 #include "cache.h"
   2 #include "delta.h"
   3 #include "pack.h"
   4 #include "csum-file.h"
   5 #include "blob.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "tree.h"
   9 #include "progress.h"
  10 #include "fsck.h"
  11
  12 static const char index_pack_usage[] =
  13 "git-index-pack [-v] [-o <index-file>] [{ ---keep | --keep=<msg> }] [--strict] { <pack-file> | --stdin [--fix-thin] [<pack-file>] }";
  14
  15 struct object_entry
  16 {
  17         struct pack_idx_entry idx;
  18         unsigned long size;
  19         unsigned int hdr_size;
  20         enum object_type type;
  21         enum object_type real_type;
  22 };
  23
  24 union delta_base {
  25         unsigned char sha1[20];
  26         off_t offset;
  27 };
  28
  29 struct base_data {
  30         struct base_data *base;
  31         struct base_data *child;
  32         struct object_entry *obj;
  33         void *data;
  34         unsigned long size;
  35 };
  36
  37 /*
  38  * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
  39  * to memcmp() only the first 20 bytes.
  40  */
  41 #define UNION_BASE_SZ   20
  42
  43 #define FLAG_LINK (1u<<20)
  44 #define FLAG_CHECKED (1u<<21)
  45
  46 struct delta_entry
  47 {
  48         union delta_base base;
  49         int obj_no;
  50 };
  51
  52 static struct object_entry *objects;
  53 static struct delta_entry *deltas;
  54 static struct base_data *base_cache;
  55 static int nr_objects;
  56 static int nr_deltas;
  57 static int nr_resolved_deltas;
  58
  59 static int from_stdin;
  60 static int strict;
  61 static int verbose;
  62
  63 static struct progress *progress;
  64
  65 /* We always read in 4kB chunks. */
  66 static unsigned char input_buffer[4096];
  67 static unsigned int input_offset, input_len;
  68 static off_t consumed_bytes;
  69 static SHA_CTX input_ctx;
  70 static uint32_t input_crc32;
  71 static int input_fd, output_fd, pack_fd;
  72
  73 static int mark_link(struct object *obj, int type, void *data)
  74 {
  75         if (!obj)
  76                 return -1;
  77
  78         if (type != OBJ_ANY && obj->type != type)
  79                 die("object type mismatch at %s", sha1_to_hex(obj->sha1));
  80
  81         obj->flags |= FLAG_LINK;
  82         return 0;
  83 }
  84
  85 /* The content of each linked object must have been checked
  86    or it must be already present in the object database */
  87 static void check_object(struct object *obj)
  88 {
  89         if (!obj)
  90                 return;
  91
  92         if (!(obj->flags & FLAG_LINK))
  93                 return;
  94
  95         if (!(obj->flags & FLAG_CHECKED)) {
  96                 unsigned long size;
  97                 int type = sha1_object_info(obj->sha1, &size);
  98                 if (type != obj->type || type <= 0)
  99                         die("object of unexpected type");
 100                 obj->flags |= FLAG_CHECKED;
 101                 return;
 102         }
 103 }
 104
 105 static void check_objects(void)
 106 {
 107         unsigned i, max;
 108
 109         max = get_max_object_index();
 110         for (i = 0; i < max; i++)
 111                 check_object(get_indexed_object(i));
 112 }
 113
 114
 115 /* Discard current buffer used content. */
 116 static void flush(void)
 117 {
 118         if (input_offset) {
 119                 if (output_fd >= 0)
 120                         write_or_die(output_fd, input_buffer, input_offset);
 121                 SHA1_Update(&input_ctx, input_buffer, input_offset);
 122                 memmove(input_buffer, input_buffer + input_offset, input_len);
 123                 input_offset = 0;
 124         }
 125 }
 126
 127 /*
 128  * Make sure at least "min" bytes are available in the buffer, and
 129  * return the pointer to the buffer.
 130  */
 131 static void *fill(int min)
 132 {
 133         if (min <= input_len)
 134                 return input_buffer + input_offset;
 135         if (min > sizeof(input_buffer))
 136                 die("cannot fill %d bytes", min);
 137         flush();
 138         do {
 139                 ssize_t ret = xread(input_fd, input_buffer + input_len,
 140                                 sizeof(input_buffer) - input_len);
 141                 if (ret <= 0) {
 142                         if (!ret)
 143                                 die("early EOF");
 144                         die("read error on input: %s", strerror(errno));
 145                 }
 146                 input_len += ret;
 147                 if (from_stdin)
 148                         display_throughput(progress, consumed_bytes + input_len);
 149         } while (input_len < min);
 150         return input_buffer;
 151 }
 152
 153 static void use(int bytes)
 154 {
 155         if (bytes > input_len)
 156                 die("used more bytes than were available");
 157         input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 158         input_len -= bytes;
 159         input_offset += bytes;
 160
 161         /* make sure off_t is sufficiently large not to wrap */
 162         if (consumed_bytes > consumed_bytes + bytes)
 163                 die("pack too large for current definition of off_t");
 164         consumed_bytes += bytes;
 165 }
 166
 167 static char *open_pack_file(char *pack_name)
 168 {
 169         if (from_stdin) {
 170                 input_fd = 0;
 171                 if (!pack_name) {
 172                         static char tmpfile[PATH_MAX];
 173                         snprintf(tmpfile, sizeof(tmpfile),
 174                                  "%s/tmp_pack_XXXXXX", get_object_directory());
 175                         output_fd = xmkstemp(tmpfile);
 176                         pack_name = xstrdup(tmpfile);
 177                 } else
 178                         output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 179                 if (output_fd < 0)
 180                         die("unable to create %s: %s\n", pack_name, strerror(errno));
 181                 pack_fd = output_fd;
 182         } else {
 183                 input_fd = open(pack_name, O_RDONLY);
 184                 if (input_fd < 0)
 185                         die("cannot open packfile '%s': %s",
 186                             pack_name, strerror(errno));
 187                 output_fd = -1;
 188                 pack_fd = input_fd;
 189         }
 190         SHA1_Init(&input_ctx);
 191         return pack_name;
 192 }
 193
 194 static void parse_pack_header(void)
 195 {
 196         struct pack_header *hdr = fill(sizeof(struct pack_header));
 197
 198         /* Header consistency check */
 199         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 200                 die("pack signature mismatch");
 201         if (!pack_version_ok(hdr->hdr_version))
 202                 die("pack version %d unsupported", ntohl(hdr->hdr_version));
 203
 204         nr_objects = ntohl(hdr->hdr_entries);
 205         use(sizeof(struct pack_header));
 206 }
 207
 208 static void bad_object(unsigned long offset, const char *format,
 209                        ...) NORETURN __attribute__((format (printf, 2, 3)));
 210
 211 static void bad_object(unsigned long offset, const char *format, ...)
 212 {
 213         va_list params;
 214         char buf[1024];
 215
 216         va_start(params, format);
 217         vsnprintf(buf, sizeof(buf), format, params);
 218         va_end(params);
 219         die("pack has bad object at offset %lu: %s", offset, buf);
 220 }
 221
 222 static void link_base_data(struct base_data *base, struct base_data *c)
 223 {
 224         if (base)
 225                 base->child = c;
 226         else
 227                 base_cache = c;
 228
 229         c->base = base;
 230         c->child = NULL;
 231 }
 232
 233 static void unlink_base_data(struct base_data *c)
 234 {
 235         struct base_data *base = c->base;
 236         if (base)
 237                 base->child = NULL;
 238         else
 239                 base_cache = NULL;
 240         free(c->data);
 241 }
 242
 243 static void *unpack_entry_data(unsigned long offset, unsigned long size)
 244 {
 245         z_stream stream;
 246         void *buf = xmalloc(size);
 247
 248         memset(&stream, 0, sizeof(stream));
 249         stream.next_out = buf;
 250         stream.avail_out = size;
 251         stream.next_in = fill(1);
 252         stream.avail_in = input_len;
 253         inflateInit(&stream);
 254
 255         for (;;) {
 256                 int ret = inflate(&stream, 0);
 257                 use(input_len - stream.avail_in);
 258                 if (stream.total_out == size && ret == Z_STREAM_END)
 259                         break;
 260                 if (ret != Z_OK)
 261                         bad_object(offset, "inflate returned %d", ret);
 262                 stream.next_in = fill(1);
 263                 stream.avail_in = input_len;
 264         }
 265         inflateEnd(&stream);
 266         return buf;
 267 }
 268
 269 static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_base)
 270 {
 271         unsigned char *p, c;
 272         unsigned long size;
 273         off_t base_offset;
 274         unsigned shift;
 275         void *data;
 276
 277         obj->idx.offset = consumed_bytes;
 278         input_crc32 = crc32(0, Z_NULL, 0);
 279
 280         p = fill(1);
 281         c = *p;
 282         use(1);
 283         obj->type = (c >> 4) & 7;
 284         size = (c & 15);
 285         shift = 4;
 286         while (c & 0x80) {
 287                 p = fill(1);
 288                 c = *p;
 289                 use(1);
 290                 size += (c & 0x7fUL) << shift;
 291                 shift += 7;
 292         }
 293         obj->size = size;
 294
 295         switch (obj->type) {
 296         case OBJ_REF_DELTA:
 297                 hashcpy(delta_base->sha1, fill(20));
 298                 use(20);
 299                 break;
 300         case OBJ_OFS_DELTA:
 301                 memset(delta_base, 0, sizeof(*delta_base));
 302                 p = fill(1);
 303                 c = *p;
 304                 use(1);
 305                 base_offset = c & 127;
 306                 while (c & 128) {
 307                         base_offset += 1;
 308                         if (!base_offset || MSB(base_offset, 7))
 309                                 bad_object(obj->idx.offset, "offset value overflow for delta base object");
 310                         p = fill(1);
 311                         c = *p;
 312                         use(1);
 313                         base_offset = (base_offset << 7) + (c & 127);
 314                 }
 315                 delta_base->offset = obj->idx.offset - base_offset;
 316                 if (delta_base->offset >= obj->idx.offset)
 317                         bad_object(obj->idx.offset, "delta base offset is out of bound");
 318                 break;
 319         case OBJ_COMMIT:
 320         case OBJ_TREE:
 321         case OBJ_BLOB:
 322         case OBJ_TAG:
 323                 break;
 324         default:
 325                 bad_object(obj->idx.offset, "unknown object type %d", obj->type);
 326         }
 327         obj->hdr_size = consumed_bytes - obj->idx.offset;
 328
 329         data = unpack_entry_data(obj->idx.offset, obj->size);
 330         obj->idx.crc32 = input_crc32;
 331         return data;
 332 }
 333
 334 static void *get_data_from_pack(struct object_entry *obj)
 335 {
 336         off_t from = obj[0].idx.offset + obj[0].hdr_size;
 337         unsigned long len = obj[1].idx.offset - from;
 338         unsigned long rdy = 0;
 339         unsigned char *src, *data;
 340         z_stream stream;
 341         int st;
 342
 343         src = xmalloc(len);
 344         data = src;
 345         do {
 346                 ssize_t n = pread(pack_fd, data + rdy, len - rdy, from + rdy);
 347                 if (n <= 0)
 348                         die("cannot pread pack file: %s", strerror(errno));
 349                 rdy += n;
 350         } while (rdy < len);
 351         data = xmalloc(obj->size);
 352         memset(&stream, 0, sizeof(stream));
 353         stream.next_out = data;
 354         stream.avail_out = obj->size;
 355         stream.next_in = src;
 356         stream.avail_in = len;
 357         inflateInit(&stream);
 358         while ((st = inflate(&stream, Z_FINISH)) == Z_OK);
 359         inflateEnd(&stream);
 360         if (st != Z_STREAM_END || stream.total_out != obj->size)
 361                 die("serious inflate inconsistency");
 362         free(src);
 363         return data;
 364 }
 365
 366 static int find_delta(const union delta_base *base)
 367 {
 368         int first = 0, last = nr_deltas;
 369
 370         while (first < last) {
 371                 int next = (first + last) / 2;
 372                 struct delta_entry *delta = &deltas[next];
 373                 int cmp;
 374
 375                 cmp = memcmp(base, &delta->base, UNION_BASE_SZ);
 376                 if (!cmp)
 377                         return next;
 378                 if (cmp < 0) {
 379                         last = next;
 380                         continue;
 381                 }
 382                 first = next+1;
 383         }
 384         return -first-1;
 385 }
 386
 387 static int find_delta_children(const union delta_base *base,
 388                                int *first_index, int *last_index)
 389 {
 390         int first = find_delta(base);
 391         int last = first;
 392         int end = nr_deltas - 1;
 393
 394         if (first < 0)
 395                 return -1;
 396         while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
 397                 --first;
 398         while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
 399                 ++last;
 400         *first_index = first;
 401         *last_index = last;
 402         return 0;
 403 }
 404
 405 static void sha1_object(const void *data, unsigned long size,
 406                         enum object_type type, unsigned char *sha1)
 407 {
 408         hash_sha1_file(data, size, typename(type), sha1);
 409         if (has_sha1_file(sha1)) {
 410                 void *has_data;
 411                 enum object_type has_type;
 412                 unsigned long has_size;
 413                 has_data = read_sha1_file(sha1, &has_type, &has_size);
 414                 if (!has_data)
 415                         die("cannot read existing object %s", sha1_to_hex(sha1));
 416                 if (size != has_size || type != has_type ||
 417                     memcmp(data, has_data, size) != 0)
 418                         die("SHA1 COLLISION FOUND WITH %s !", sha1_to_hex(sha1));
 419                 free(has_data);
 420         }
 421         if (strict) {
 422                 if (type == OBJ_BLOB) {
 423                         struct blob *blob = lookup_blob(sha1);
 424                         if (blob)
 425                                 blob->object.flags |= FLAG_CHECKED;
 426                         else
 427                                 die("invalid blob object %s", sha1_to_hex(sha1));
 428                 } else {
 429                         struct object *obj;
 430                         int eaten;
 431                         void *buf = (void *) data;
 432
 433                         /*
 434                          * we do not need to free the memory here, as the
 435                          * buf is deleted by the caller.
 436                          */
 437                         obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 438                         if (!obj)
 439                                 die("invalid %s", typename(type));
 440                         if (fsck_object(obj, 1, fsck_error_function))
 441                                 die("Error in object");
 442                         if (fsck_walk(obj, mark_link, 0))
 443                                 die("Not all child objects of %s are reachable", sha1_to_hex(obj->sha1));
 444
 445                         if (obj->type == OBJ_TREE) {
 446                                 struct tree *item = (struct tree *) obj;
 447                                 item->buffer = NULL;
 448                         }
 449                         if (obj->type == OBJ_COMMIT) {
 450                                 struct commit *commit = (struct commit *) obj;
 451                                 commit->buffer = NULL;
 452                         }
 453                         obj->flags |= FLAG_CHECKED;
 454                 }
 455         }
 456 }
 457
 458 static void resolve_delta(struct object_entry *delta_obj,
 459                           struct base_data *base_obj, enum object_type type)
 460 {
 461         void *delta_data;
 462         unsigned long delta_size;
 463         union delta_base delta_base;
 464         int j, first, last;
 465         struct base_data result;
 466
 467         delta_obj->real_type = type;
 468         delta_data = get_data_from_pack(delta_obj);
 469         delta_size = delta_obj->size;
 470         result.data = patch_delta(base_obj->data, base_obj->size,
 471                              delta_data, delta_size,
 472                              &result.size);
 473         free(delta_data);
 474         if (!result.data)
 475                 bad_object(delta_obj->idx.offset, "failed to apply delta");
 476         sha1_object(result.data, result.size, type, delta_obj->idx.sha1);
 477         nr_resolved_deltas++;
 478
 479         result.obj = delta_obj;
 480         link_base_data(base_obj, &result);
 481
 482         hashcpy(delta_base.sha1, delta_obj->idx.sha1);
 483         if (!find_delta_children(&delta_base, &first, &last)) {
 484                 for (j = first; j <= last; j++) {
 485                         struct object_entry *child = objects + deltas[j].obj_no;
 486                         if (child->real_type == OBJ_REF_DELTA)
 487                                 resolve_delta(child, &result, type);
 488                 }
 489         }
 490
 491         memset(&delta_base, 0, sizeof(delta_base));
 492         delta_base.offset = delta_obj->idx.offset;
 493         if (!find_delta_children(&delta_base, &first, &last)) {
 494                 for (j = first; j <= last; j++) {
 495                         struct object_entry *child = objects + deltas[j].obj_no;
 496                         if (child->real_type == OBJ_OFS_DELTA)
 497                                 resolve_delta(child, &result, type);
 498                 }
 499         }
 500
 501         unlink_base_data(&result);
 502 }
 503
 504 static int compare_delta_entry(const void *a, const void *b)
 505 {
 506         const struct delta_entry *delta_a = a;
 507         const struct delta_entry *delta_b = b;
 508         return memcmp(&delta_a->base, &delta_b->base, UNION_BASE_SZ);
 509 }
 510
 511 /* Parse all objects and return the pack content SHA1 hash */
 512 static void parse_pack_objects(unsigned char *sha1)
 513 {
 514         int i;
 515         struct delta_entry *delta = deltas;
 516         struct stat st;
 517
 518         /*
 519          * First pass:
 520          * - find locations of all objects;
 521          * - calculate SHA1 of all non-delta objects;
 522          * - remember base (SHA1 or offset) for all deltas.
 523          */
 524         if (verbose)
 525                 progress = start_progress(
 526                                 from_stdin ? "Receiving objects" : "Indexing objects",
 527                                 nr_objects);
 528         for (i = 0; i < nr_objects; i++) {
 529                 struct object_entry *obj = &objects[i];
 530                 void *data = unpack_raw_entry(obj, &delta->base);
 531                 obj->real_type = obj->type;
 532                 if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
 533                         nr_deltas++;
 534                         delta->obj_no = i;
 535                         delta++;
 536                 } else
 537                         sha1_object(data, obj->size, obj->type, obj->idx.sha1);
 538                 free(data);
 539                 display_progress(progress, i+1);
 540         }
 541         objects[i].idx.offset = consumed_bytes;
 542         stop_progress(&progress);
 543
 544         /* Check pack integrity */
 545         flush();
 546         SHA1_Final(sha1, &input_ctx);
 547         if (hashcmp(fill(20), sha1))
 548                 die("pack is corrupted (SHA1 mismatch)");
 549         use(20);
 550
 551         /* If input_fd is a file, we should have reached its end now. */
 552         if (fstat(input_fd, &st))
 553                 die("cannot fstat packfile: %s", strerror(errno));
 554         if (S_ISREG(st.st_mode) &&
 555                         lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
 556                 die("pack has junk at the end");
 557
 558         if (!nr_deltas)
 559                 return;
 560
 561         /* Sort deltas by base SHA1/offset for fast searching */
 562         qsort(deltas, nr_deltas, sizeof(struct delta_entry),
 563               compare_delta_entry);
 564
 565         /*
 566          * Second pass:
 567          * - for all non-delta objects, look if it is used as a base for
 568          *   deltas;
 569          * - if used as a base, uncompress the object and apply all deltas,
 570          *   recursively checking if the resulting object is used as a base
 571          *   for some more deltas.
 572          */
 573         if (verbose)
 574                 progress = start_progress("Resolving deltas", nr_deltas);
 575         for (i = 0; i < nr_objects; i++) {
 576                 struct object_entry *obj = &objects[i];
 577                 union delta_base base;
 578                 int j, ref, ref_first, ref_last, ofs, ofs_first, ofs_last;
 579                 struct base_data base_obj;
 580
 581                 if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA)
 582                         continue;
 583                 hashcpy(base.sha1, obj->idx.sha1);
 584                 ref = !find_delta_children(&base, &ref_first, &ref_last);
 585                 memset(&base, 0, sizeof(base));
 586                 base.offset = obj->idx.offset;
 587                 ofs = !find_delta_children(&base, &ofs_first, &ofs_last);
 588                 if (!ref && !ofs)
 589                         continue;
 590                 base_obj.data = get_data_from_pack(obj);
 591                 base_obj.size = obj->size;
 592                 base_obj.obj = obj;
 593                 link_base_data(NULL, &base_obj);
 594
 595                 if (ref)
 596                         for (j = ref_first; j <= ref_last; j++) {
 597                                 struct object_entry *child = objects + deltas[j].obj_no;
 598                                 if (child->real_type == OBJ_REF_DELTA)
 599                                         resolve_delta(child, &base_obj, obj->type);
 600                         }
 601                 if (ofs)
 602                         for (j = ofs_first; j <= ofs_last; j++) {
 603                                 struct object_entry *child = objects + deltas[j].obj_no;
 604                                 if (child->real_type == OBJ_OFS_DELTA)
 605                                         resolve_delta(child, &base_obj, obj->type);
 606                         }
 607                 unlink_base_data(&base_obj);
 608                 display_progress(progress, nr_resolved_deltas);
 609         }
 610 }
 611
 612 static int write_compressed(int fd, void *in, unsigned int size, uint32_t *obj_crc)
 613 {
 614         z_stream stream;
 615         unsigned long maxsize;
 616         void *out;
 617
 618         memset(&stream, 0, sizeof(stream));
 619         deflateInit(&stream, zlib_compression_level);
 620         maxsize = deflateBound(&stream, size);
 621         out = xmalloc(maxsize);
 622
 623         /* Compress it */
 624         stream.next_in = in;
 625         stream.avail_in = size;
 626         stream.next_out = out;
 627         stream.avail_out = maxsize;
 628         while (deflate(&stream, Z_FINISH) == Z_OK);
 629         deflateEnd(&stream);
 630
 631         size = stream.total_out;
 632         write_or_die(fd, out, size);
 633         *obj_crc = crc32(*obj_crc, out, size);
 634         free(out);
 635         return size;
 636 }
 637
 638 static struct object_entry *append_obj_to_pack(
 639                                const unsigned char *sha1, void *buf,
 640                                unsigned long size, enum object_type type)
 641 {
 642         struct object_entry *obj = &objects[nr_objects++];
 643         unsigned char header[10];
 644         unsigned long s = size;
 645         int n = 0;
 646         unsigned char c = (type << 4) | (s & 15);
 647         s >>= 4;
 648         while (s) {
 649                 header[n++] = c | 0x80;
 650                 c = s & 0x7f;
 651                 s >>= 7;
 652         }
 653         header[n++] = c;
 654         write_or_die(output_fd, header, n);
 655         obj[0].idx.crc32 = crc32(0, Z_NULL, 0);
 656         obj[0].idx.crc32 = crc32(obj[0].idx.crc32, header, n);
 657         obj[1].idx.offset = obj[0].idx.offset + n;
 658         obj[1].idx.offset += write_compressed(output_fd, buf, size, &obj[0].idx.crc32);
 659         hashcpy(obj->idx.sha1, sha1);
 660         return obj;
 661 }
 662
 663 static int delta_pos_compare(const void *_a, const void *_b)
 664 {
 665         struct delta_entry *a = *(struct delta_entry **)_a;
 666         struct delta_entry *b = *(struct delta_entry **)_b;
 667         return a->obj_no - b->obj_no;
 668 }
 669
 670 static void fix_unresolved_deltas(int nr_unresolved)
 671 {
 672         struct delta_entry **sorted_by_pos;
 673         int i, n = 0;
 674
 675         /*
 676          * Since many unresolved deltas may well be themselves base objects
 677          * for more unresolved deltas, we really want to include the
 678          * smallest number of base objects that would cover as much delta
 679          * as possible by picking the
 680          * trunc deltas first, allowing for other deltas to resolve without
 681          * additional base objects.  Since most base objects are to be found
 682          * before deltas depending on them, a good heuristic is to start
 683          * resolving deltas in the same order as their position in the pack.
 684          */
 685         sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
 686         for (i = 0; i < nr_deltas; i++) {
 687                 if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
 688                         continue;
 689                 sorted_by_pos[n++] = &deltas[i];
 690         }
 691         qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
 692
 693         for (i = 0; i < n; i++) {
 694                 struct delta_entry *d = sorted_by_pos[i];
 695                 enum object_type type;
 696                 int j, first, last;
 697                 struct base_data base_obj;
 698
 699                 if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
 700                         continue;
 701                 base_obj.data = read_sha1_file(d->base.sha1, &type, &base_obj.size);
 702                 if (!base_obj.data)
 703                         continue;
 704
 705                 if (check_sha1_signature(d->base.sha1, base_obj.data,
 706                                 base_obj.size, typename(type)))
 707                         die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
 708                 base_obj.obj = append_obj_to_pack(d->base.sha1, base_obj.data,
 709                         base_obj.size, type);
 710                 link_base_data(NULL, &base_obj);
 711
 712                 find_delta_children(&d->base, &first, &last);
 713                 for (j = first; j <= last; j++) {
 714                         struct object_entry *child = objects + deltas[j].obj_no;
 715                         if (child->real_type == OBJ_REF_DELTA)
 716                                 resolve_delta(child, &base_obj, type);
 717                 }
 718
 719                 unlink_base_data(&base_obj);
 720                 display_progress(progress, nr_resolved_deltas);
 721         }
 722         free(sorted_by_pos);
 723 }
 724
 725 static void final(const char *final_pack_name, const char *curr_pack_name,
 726                   const char *final_index_name, const char *curr_index_name,
 727                   const char *keep_name, const char *keep_msg,
 728                   unsigned char *sha1)
 729 {
 730         const char *report = "pack";
 731         char name[PATH_MAX];
 732         int err;
 733
 734         if (!from_stdin) {
 735                 close(input_fd);
 736         } else {
 737                 fsync_or_die(output_fd, curr_pack_name);
 738                 err = close(output_fd);
 739                 if (err)
 740                         die("error while closing pack file: %s", strerror(errno));
 741                 chmod(curr_pack_name, 0444);
 742         }
 743
 744         if (keep_msg) {
 745                 int keep_fd, keep_msg_len = strlen(keep_msg);
 746                 if (!keep_name) {
 747                         snprintf(name, sizeof(name), "%s/pack/pack-%s.keep",
 748                                  get_object_directory(), sha1_to_hex(sha1));
 749                         keep_name = name;
 750                 }
 751                 keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
 752                 if (keep_fd < 0) {
 753                         if (errno != EEXIST)
 754                                 die("cannot write keep file");
 755                 } else {
 756                         if (keep_msg_len > 0) {
 757                                 write_or_die(keep_fd, keep_msg, keep_msg_len);
 758                                 write_or_die(keep_fd, "\n", 1);
 759                         }
 760                         if (close(keep_fd) != 0)
 761                                 die("cannot write keep file");
 762                         report = "keep";
 763                 }
 764         }
 765
 766         if (final_pack_name != curr_pack_name) {
 767                 if (!final_pack_name) {
 768                         snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
 769                                  get_object_directory(), sha1_to_hex(sha1));
 770                         final_pack_name = name;
 771                 }
 772                 if (move_temp_to_file(curr_pack_name, final_pack_name))
 773                         die("cannot store pack file");
 774         }
 775
 776         chmod(curr_index_name, 0444);
 777         if (final_index_name != curr_index_name) {
 778                 if (!final_index_name) {
 779                         snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
 780                                  get_object_directory(), sha1_to_hex(sha1));
 781                         final_index_name = name;
 782                 }
 783                 if (move_temp_to_file(curr_index_name, final_index_name))
 784                         die("cannot store index file");
 785         }
 786
 787         if (!from_stdin) {
 788                 printf("%s\n", sha1_to_hex(sha1));
 789         } else {
 790                 char buf[48];
 791                 int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
 792                                    report, sha1_to_hex(sha1));
 793                 write_or_die(1, buf, len);
 794
 795                 /*
 796                  * Let's just mimic git-unpack-objects here and write
 797                  * the last part of the input buffer to stdout.
 798                  */
 799                 while (input_len) {
 800                         err = xwrite(1, input_buffer + input_offset, input_len);
 801                         if (err <= 0)
 802                                 break;
 803                         input_len -= err;
 804                         input_offset += err;
 805                 }
 806         }
 807 }
 808
 809 static int git_index_pack_config(const char *k, const char *v, void *cb)
 810 {
 811         if (!strcmp(k, "pack.indexversion")) {
 812                 pack_idx_default_version = git_config_int(k, v);
 813                 if (pack_idx_default_version > 2)
 814                         die("bad pack.indexversion=%d", pack_idx_default_version);
 815                 return 0;
 816         }
 817         return git_default_config(k, v, cb);
 818 }
 819
 820 int main(int argc, char **argv)
 821 {
 822         int i, fix_thin_pack = 0;
 823         char *curr_pack, *pack_name = NULL;
 824         char *curr_index, *index_name = NULL;
 825         const char *keep_name = NULL, *keep_msg = NULL;
 826         char *index_name_buf = NULL, *keep_name_buf = NULL;
 827         struct pack_idx_entry **idx_objects;
 828         unsigned char sha1[20];
 829
 830         git_config(git_index_pack_config, NULL);
 831
 832         for (i = 1; i < argc; i++) {
 833                 char *arg = argv[i];
 834
 835                 if (*arg == '-') {
 836                         if (!strcmp(arg, "--stdin")) {
 837                                 from_stdin = 1;
 838                         } else if (!strcmp(arg, "--fix-thin")) {
 839                                 fix_thin_pack = 1;
 840                         } else if (!strcmp(arg, "--strict")) {
 841                                 strict = 1;
 842                         } else if (!strcmp(arg, "--keep")) {
 843                                 keep_msg = "";
 844                         } else if (!prefixcmp(arg, "--keep=")) {
 845                                 keep_msg = arg + 7;
 846                         } else if (!prefixcmp(arg, "--pack_header=")) {
 847                                 struct pack_header *hdr;
 848                                 char *c;
 849
 850                                 hdr = (struct pack_header *)input_buffer;
 851                                 hdr->hdr_signature = htonl(PACK_SIGNATURE);
 852                                 hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
 853                                 if (*c != ',')
 854                                         die("bad %s", arg);
 855                                 hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
 856                                 if (*c)
 857                                         die("bad %s", arg);
 858                                 input_len = sizeof(*hdr);
 859                         } else if (!strcmp(arg, "-v")) {
 860                                 verbose = 1;
 861                         } else if (!strcmp(arg, "-o")) {
 862                                 if (index_name || (i+1) >= argc)
 863                                         usage(index_pack_usage);
 864                                 index_name = argv[++i];
 865                         } else if (!prefixcmp(arg, "--index-version=")) {
 866                                 char *c;
 867                                 pack_idx_default_version = strtoul(arg + 16, &c, 10);
 868                                 if (pack_idx_default_version > 2)
 869                                         die("bad %s", arg);
 870                                 if (*c == ',')
 871                                         pack_idx_off32_limit = strtoul(c+1, &c, 0);
 872                                 if (*c || pack_idx_off32_limit & 0x80000000)
 873                                         die("bad %s", arg);
 874                         } else
 875                                 usage(index_pack_usage);
 876                         continue;
 877                 }
 878
 879                 if (pack_name)
 880                         usage(index_pack_usage);
 881                 pack_name = arg;
 882         }
 883
 884         if (!pack_name && !from_stdin)
 885                 usage(index_pack_usage);
 886         if (fix_thin_pack && !from_stdin)
 887                 die("--fix-thin cannot be used without --stdin");
 888         if (!index_name && pack_name) {
 889                 int len = strlen(pack_name);
 890                 if (!has_extension(pack_name, ".pack"))
 891                         die("packfile name '%s' does not end with '.pack'",
 892                             pack_name);
 893                 index_name_buf = xmalloc(len);
 894                 memcpy(index_name_buf, pack_name, len - 5);
 895                 strcpy(index_name_buf + len - 5, ".idx");
 896                 index_name = index_name_buf;
 897         }
 898         if (keep_msg && !keep_name && pack_name) {
 899                 int len = strlen(pack_name);
 900                 if (!has_extension(pack_name, ".pack"))
 901                         die("packfile name '%s' does not end with '.pack'",
 902                             pack_name);
 903                 keep_name_buf = xmalloc(len);
 904                 memcpy(keep_name_buf, pack_name, len - 5);
 905                 strcpy(keep_name_buf + len - 5, ".keep");
 906                 keep_name = keep_name_buf;
 907         }
 908
 909         curr_pack = open_pack_file(pack_name);
 910         parse_pack_header();
 911         objects = xmalloc((nr_objects + 1) * sizeof(struct object_entry));
 912         deltas = xmalloc(nr_objects * sizeof(struct delta_entry));
 913         parse_pack_objects(sha1);
 914         if (nr_deltas == nr_resolved_deltas) {
 915                 stop_progress(&progress);
 916                 /* Flush remaining pack final 20-byte SHA1. */
 917                 flush();
 918         } else {
 919                 if (fix_thin_pack) {
 920                         char msg[48];
 921                         int nr_unresolved = nr_deltas - nr_resolved_deltas;
 922                         int nr_objects_initial = nr_objects;
 923                         if (nr_unresolved <= 0)
 924                                 die("confusion beyond insanity");
 925                         objects = xrealloc(objects,
 926                                            (nr_objects + nr_unresolved + 1)
 927                                            * sizeof(*objects));
 928                         fix_unresolved_deltas(nr_unresolved);
 929                         sprintf(msg, "completed with %d local objects",
 930                                 nr_objects - nr_objects_initial);
 931                         stop_progress_msg(&progress, msg);
 932                         fixup_pack_header_footer(output_fd, sha1,
 933                                                  curr_pack, nr_objects);
 934                 }
 935                 if (nr_deltas != nr_resolved_deltas)
 936                         die("pack has %d unresolved deltas",
 937                             nr_deltas - nr_resolved_deltas);
 938         }
 939         free(deltas);
 940         if (strict)
 941                 check_objects();
 942
 943         idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
 944         for (i = 0; i < nr_objects; i++)
 945                 idx_objects[i] = &objects[i].idx;
 946         curr_index = write_idx_file(index_name, idx_objects, nr_objects, sha1);
 947         free(idx_objects);
 948
 949         final(pack_name, curr_pack,
 950                 index_name, curr_index,
 951                 keep_name, keep_msg,
 952                 sha1);
 953         free(objects);
 954         free(index_name_buf);
 955         free(keep_name_buf);
 956         if (pack_name == NULL)
 957                 free(curr_pack);
 958         if (index_name == NULL)
 959                 free(curr_index);
 960
 961         return 0;
 962 }