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