index-pack.con commit blame: show "previous" information in --porcelain/--incremental format (96e1170)
   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
  12static 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
  15struct 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
  24union delta_base {
  25        unsigned char sha1[20];
  26        off_t offset;
  27};
  28
  29struct 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
  46struct delta_entry
  47{
  48        union delta_base base;
  49        int obj_no;
  50};
  51
  52static struct object_entry *objects;
  53static struct delta_entry *deltas;
  54static struct base_data *base_cache;
  55static size_t base_cache_used;
  56static int nr_objects;
  57static int nr_deltas;
  58static int nr_resolved_deltas;
  59
  60static int from_stdin;
  61static int strict;
  62static int verbose;
  63
  64static struct progress *progress;
  65
  66/* We always read in 4kB chunks. */
  67static unsigned char input_buffer[4096];
  68static unsigned int input_offset, input_len;
  69static off_t consumed_bytes;
  70static git_SHA_CTX input_ctx;
  71static uint32_t input_crc32;
  72static int input_fd, output_fd, pack_fd;
  73
  74static int mark_link(struct object *obj, int type, void *data)
  75{
  76        if (!obj)
  77                return -1;
  78
  79        if (type != OBJ_ANY && obj->type != type)
  80                die("object type mismatch at %s", sha1_to_hex(obj->sha1));
  81
  82        obj->flags |= FLAG_LINK;
  83        return 0;
  84}
  85
  86/* The content of each linked object must have been checked
  87   or it must be already present in the object database */
  88static void check_object(struct object *obj)
  89{
  90        if (!obj)
  91                return;
  92
  93        if (!(obj->flags & FLAG_LINK))
  94                return;
  95
  96        if (!(obj->flags & FLAG_CHECKED)) {
  97                unsigned long size;
  98                int type = sha1_object_info(obj->sha1, &size);
  99                if (type != obj->type || type <= 0)
 100                        die("object of unexpected type");
 101                obj->flags |= FLAG_CHECKED;
 102                return;
 103        }
 104}
 105
 106static void check_objects(void)
 107{
 108        unsigned i, max;
 109
 110        max = get_max_object_index();
 111        for (i = 0; i < max; i++)
 112                check_object(get_indexed_object(i));
 113}
 114
 115
 116/* Discard current buffer used content. */
 117static void flush(void)
 118{
 119        if (input_offset) {
 120                if (output_fd >= 0)
 121                        write_or_die(output_fd, input_buffer, input_offset);
 122                git_SHA1_Update(&input_ctx, input_buffer, input_offset);
 123                memmove(input_buffer, input_buffer + input_offset, input_len);
 124                input_offset = 0;
 125        }
 126}
 127
 128/*
 129 * Make sure at least "min" bytes are available in the buffer, and
 130 * return the pointer to the buffer.
 131 */
 132static void *fill(int min)
 133{
 134        if (min <= input_len)
 135                return input_buffer + input_offset;
 136        if (min > sizeof(input_buffer))
 137                die("cannot fill %d bytes", min);
 138        flush();
 139        do {
 140                ssize_t ret = xread(input_fd, input_buffer + input_len,
 141                                sizeof(input_buffer) - input_len);
 142                if (ret <= 0) {
 143                        if (!ret)
 144                                die("early EOF");
 145                        die("read error on input: %s", strerror(errno));
 146                }
 147                input_len += ret;
 148                if (from_stdin)
 149                        display_throughput(progress, consumed_bytes + input_len);
 150        } while (input_len < min);
 151        return input_buffer;
 152}
 153
 154static void use(int bytes)
 155{
 156        if (bytes > input_len)
 157                die("used more bytes than were available");
 158        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 159        input_len -= bytes;
 160        input_offset += bytes;
 161
 162        /* make sure off_t is sufficiently large not to wrap */
 163        if (consumed_bytes > consumed_bytes + bytes)
 164                die("pack too large for current definition of off_t");
 165        consumed_bytes += bytes;
 166}
 167
 168static char *open_pack_file(char *pack_name)
 169{
 170        if (from_stdin) {
 171                input_fd = 0;
 172                if (!pack_name) {
 173                        static char tmpfile[PATH_MAX];
 174                        snprintf(tmpfile, sizeof(tmpfile),
 175                                 "%s/pack/tmp_pack_XXXXXX", get_object_directory());
 176                        output_fd = xmkstemp(tmpfile);
 177                        pack_name = xstrdup(tmpfile);
 178                } else
 179                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 180                if (output_fd < 0)
 181                        die("unable to create %s: %s\n", pack_name, strerror(errno));
 182                pack_fd = output_fd;
 183        } else {
 184                input_fd = open(pack_name, O_RDONLY);
 185                if (input_fd < 0)
 186                        die("cannot open packfile '%s': %s",
 187                            pack_name, strerror(errno));
 188                output_fd = -1;
 189                pack_fd = input_fd;
 190        }
 191        git_SHA1_Init(&input_ctx);
 192        return pack_name;
 193}
 194
 195static void parse_pack_header(void)
 196{
 197        struct pack_header *hdr = fill(sizeof(struct pack_header));
 198
 199        /* Header consistency check */
 200        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 201                die("pack signature mismatch");
 202        if (!pack_version_ok(hdr->hdr_version))
 203                die("pack version %"PRIu32" unsupported",
 204                        ntohl(hdr->hdr_version));
 205
 206        nr_objects = ntohl(hdr->hdr_entries);
 207        use(sizeof(struct pack_header));
 208}
 209
 210static void bad_object(unsigned long offset, const char *format,
 211                       ...) NORETURN __attribute__((format (printf, 2, 3)));
 212
 213static void bad_object(unsigned long offset, const char *format, ...)
 214{
 215        va_list params;
 216        char buf[1024];
 217
 218        va_start(params, format);
 219        vsnprintf(buf, sizeof(buf), format, params);
 220        va_end(params);
 221        die("pack has bad object at offset %lu: %s", offset, buf);
 222}
 223
 224static void prune_base_data(struct base_data *retain)
 225{
 226        struct base_data *b = base_cache;
 227        for (b = base_cache;
 228             base_cache_used > delta_base_cache_limit && b;
 229             b = b->child) {
 230                if (b->data && b != retain) {
 231                        free(b->data);
 232                        b->data = NULL;
 233                        base_cache_used -= b->size;
 234                }
 235        }
 236}
 237
 238static void link_base_data(struct base_data *base, struct base_data *c)
 239{
 240        if (base)
 241                base->child = c;
 242        else
 243                base_cache = c;
 244
 245        c->base = base;
 246        c->child = NULL;
 247        base_cache_used += c->size;
 248        prune_base_data(c);
 249}
 250
 251static void unlink_base_data(struct base_data *c)
 252{
 253        struct base_data *base = c->base;
 254        if (base)
 255                base->child = NULL;
 256        else
 257                base_cache = NULL;
 258        if (c->data) {
 259                free(c->data);
 260                base_cache_used -= c->size;
 261        }
 262}
 263
 264static void *unpack_entry_data(unsigned long offset, unsigned long size)
 265{
 266        z_stream stream;
 267        void *buf = xmalloc(size);
 268
 269        memset(&stream, 0, sizeof(stream));
 270        stream.next_out = buf;
 271        stream.avail_out = size;
 272        stream.next_in = fill(1);
 273        stream.avail_in = input_len;
 274        inflateInit(&stream);
 275
 276        for (;;) {
 277                int ret = inflate(&stream, 0);
 278                use(input_len - stream.avail_in);
 279                if (stream.total_out == size && ret == Z_STREAM_END)
 280                        break;
 281                if (ret != Z_OK)
 282                        bad_object(offset, "inflate returned %d", ret);
 283                stream.next_in = fill(1);
 284                stream.avail_in = input_len;
 285        }
 286        inflateEnd(&stream);
 287        return buf;
 288}
 289
 290static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_base)
 291{
 292        unsigned char *p, c;
 293        unsigned long size;
 294        off_t base_offset;
 295        unsigned shift;
 296        void *data;
 297
 298        obj->idx.offset = consumed_bytes;
 299        input_crc32 = crc32(0, Z_NULL, 0);
 300
 301        p = fill(1);
 302        c = *p;
 303        use(1);
 304        obj->type = (c >> 4) & 7;
 305        size = (c & 15);
 306        shift = 4;
 307        while (c & 0x80) {
 308                p = fill(1);
 309                c = *p;
 310                use(1);
 311                size += (c & 0x7fUL) << shift;
 312                shift += 7;
 313        }
 314        obj->size = size;
 315
 316        switch (obj->type) {
 317        case OBJ_REF_DELTA:
 318                hashcpy(delta_base->sha1, fill(20));
 319                use(20);
 320                break;
 321        case OBJ_OFS_DELTA:
 322                memset(delta_base, 0, sizeof(*delta_base));
 323                p = fill(1);
 324                c = *p;
 325                use(1);
 326                base_offset = c & 127;
 327                while (c & 128) {
 328                        base_offset += 1;
 329                        if (!base_offset || MSB(base_offset, 7))
 330                                bad_object(obj->idx.offset, "offset value overflow for delta base object");
 331                        p = fill(1);
 332                        c = *p;
 333                        use(1);
 334                        base_offset = (base_offset << 7) + (c & 127);
 335                }
 336                delta_base->offset = obj->idx.offset - base_offset;
 337                if (delta_base->offset >= obj->idx.offset)
 338                        bad_object(obj->idx.offset, "delta base offset is out of bound");
 339                break;
 340        case OBJ_COMMIT:
 341        case OBJ_TREE:
 342        case OBJ_BLOB:
 343        case OBJ_TAG:
 344                break;
 345        default:
 346                bad_object(obj->idx.offset, "unknown object type %d", obj->type);
 347        }
 348        obj->hdr_size = consumed_bytes - obj->idx.offset;
 349
 350        data = unpack_entry_data(obj->idx.offset, obj->size);
 351        obj->idx.crc32 = input_crc32;
 352        return data;
 353}
 354
 355static void *get_data_from_pack(struct object_entry *obj)
 356{
 357        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 358        unsigned long len = obj[1].idx.offset - from;
 359        unsigned long rdy = 0;
 360        unsigned char *src, *data;
 361        z_stream stream;
 362        int st;
 363
 364        src = xmalloc(len);
 365        data = src;
 366        do {
 367                ssize_t n = pread(pack_fd, data + rdy, len - rdy, from + rdy);
 368                if (n < 0)
 369                        die("cannot pread pack file: %s", strerror(errno));
 370                if (!n)
 371                        die("premature end of pack file, %lu bytes missing",
 372                            len - rdy);
 373                rdy += n;
 374        } while (rdy < len);
 375        data = xmalloc(obj->size);
 376        memset(&stream, 0, sizeof(stream));
 377        stream.next_out = data;
 378        stream.avail_out = obj->size;
 379        stream.next_in = src;
 380        stream.avail_in = len;
 381        inflateInit(&stream);
 382        while ((st = inflate(&stream, Z_FINISH)) == Z_OK);
 383        inflateEnd(&stream);
 384        if (st != Z_STREAM_END || stream.total_out != obj->size)
 385                die("serious inflate inconsistency");
 386        free(src);
 387        return data;
 388}
 389
 390static int find_delta(const union delta_base *base)
 391{
 392        int first = 0, last = nr_deltas;
 393
 394        while (first < last) {
 395                int next = (first + last) / 2;
 396                struct delta_entry *delta = &deltas[next];
 397                int cmp;
 398
 399                cmp = memcmp(base, &delta->base, UNION_BASE_SZ);
 400                if (!cmp)
 401                        return next;
 402                if (cmp < 0) {
 403                        last = next;
 404                        continue;
 405                }
 406                first = next+1;
 407        }
 408        return -first-1;
 409}
 410
 411static int find_delta_children(const union delta_base *base,
 412                               int *first_index, int *last_index)
 413{
 414        int first = find_delta(base);
 415        int last = first;
 416        int end = nr_deltas - 1;
 417
 418        if (first < 0)
 419                return -1;
 420        while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
 421                --first;
 422        while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
 423                ++last;
 424        *first_index = first;
 425        *last_index = last;
 426        return 0;
 427}
 428
 429static void sha1_object(const void *data, unsigned long size,
 430                        enum object_type type, unsigned char *sha1)
 431{
 432        hash_sha1_file(data, size, typename(type), sha1);
 433        if (has_sha1_file(sha1)) {
 434                void *has_data;
 435                enum object_type has_type;
 436                unsigned long has_size;
 437                has_data = read_sha1_file(sha1, &has_type, &has_size);
 438                if (!has_data)
 439                        die("cannot read existing object %s", sha1_to_hex(sha1));
 440                if (size != has_size || type != has_type ||
 441                    memcmp(data, has_data, size) != 0)
 442                        die("SHA1 COLLISION FOUND WITH %s !", sha1_to_hex(sha1));
 443                free(has_data);
 444        }
 445        if (strict) {
 446                if (type == OBJ_BLOB) {
 447                        struct blob *blob = lookup_blob(sha1);
 448                        if (blob)
 449                                blob->object.flags |= FLAG_CHECKED;
 450                        else
 451                                die("invalid blob object %s", sha1_to_hex(sha1));
 452                } else {
 453                        struct object *obj;
 454                        int eaten;
 455                        void *buf = (void *) data;
 456
 457                        /*
 458                         * we do not need to free the memory here, as the
 459                         * buf is deleted by the caller.
 460                         */
 461                        obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 462                        if (!obj)
 463                                die("invalid %s", typename(type));
 464                        if (fsck_object(obj, 1, fsck_error_function))
 465                                die("Error in object");
 466                        if (fsck_walk(obj, mark_link, 0))
 467                                die("Not all child objects of %s are reachable", sha1_to_hex(obj->sha1));
 468
 469                        if (obj->type == OBJ_TREE) {
 470                                struct tree *item = (struct tree *) obj;
 471                                item->buffer = NULL;
 472                        }
 473                        if (obj->type == OBJ_COMMIT) {
 474                                struct commit *commit = (struct commit *) obj;
 475                                commit->buffer = NULL;
 476                        }
 477                        obj->flags |= FLAG_CHECKED;
 478                }
 479        }
 480}
 481
 482static void *get_base_data(struct base_data *c)
 483{
 484        if (!c->data) {
 485                struct object_entry *obj = c->obj;
 486
 487                if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
 488                        void *base = get_base_data(c->base);
 489                        void *raw = get_data_from_pack(obj);
 490                        c->data = patch_delta(
 491                                base, c->base->size,
 492                                raw, obj->size,
 493                                &c->size);
 494                        free(raw);
 495                        if (!c->data)
 496                                bad_object(obj->idx.offset, "failed to apply delta");
 497                } else
 498                        c->data = get_data_from_pack(obj);
 499
 500                base_cache_used += c->size;
 501                prune_base_data(c);
 502        }
 503        return c->data;
 504}
 505
 506static void resolve_delta(struct object_entry *delta_obj,
 507                          struct base_data *base_obj, enum object_type type)
 508{
 509        void *delta_data;
 510        unsigned long delta_size;
 511        union delta_base delta_base;
 512        int j, first, last;
 513        struct base_data result;
 514
 515        delta_obj->real_type = type;
 516        delta_data = get_data_from_pack(delta_obj);
 517        delta_size = delta_obj->size;
 518        result.data = patch_delta(get_base_data(base_obj), base_obj->size,
 519                             delta_data, delta_size,
 520                             &result.size);
 521        free(delta_data);
 522        if (!result.data)
 523                bad_object(delta_obj->idx.offset, "failed to apply delta");
 524        sha1_object(result.data, result.size, type, delta_obj->idx.sha1);
 525        nr_resolved_deltas++;
 526
 527        result.obj = delta_obj;
 528        link_base_data(base_obj, &result);
 529
 530        hashcpy(delta_base.sha1, delta_obj->idx.sha1);
 531        if (!find_delta_children(&delta_base, &first, &last)) {
 532                for (j = first; j <= last; j++) {
 533                        struct object_entry *child = objects + deltas[j].obj_no;
 534                        if (child->real_type == OBJ_REF_DELTA)
 535                                resolve_delta(child, &result, type);
 536                }
 537        }
 538
 539        memset(&delta_base, 0, sizeof(delta_base));
 540        delta_base.offset = delta_obj->idx.offset;
 541        if (!find_delta_children(&delta_base, &first, &last)) {
 542                for (j = first; j <= last; j++) {
 543                        struct object_entry *child = objects + deltas[j].obj_no;
 544                        if (child->real_type == OBJ_OFS_DELTA)
 545                                resolve_delta(child, &result, type);
 546                }
 547        }
 548
 549        unlink_base_data(&result);
 550}
 551
 552static int compare_delta_entry(const void *a, const void *b)
 553{
 554        const struct delta_entry *delta_a = a;
 555        const struct delta_entry *delta_b = b;
 556        return memcmp(&delta_a->base, &delta_b->base, UNION_BASE_SZ);
 557}
 558
 559/* Parse all objects and return the pack content SHA1 hash */
 560static void parse_pack_objects(unsigned char *sha1)
 561{
 562        int i;
 563        struct delta_entry *delta = deltas;
 564        struct stat st;
 565
 566        /*
 567         * First pass:
 568         * - find locations of all objects;
 569         * - calculate SHA1 of all non-delta objects;
 570         * - remember base (SHA1 or offset) for all deltas.
 571         */
 572        if (verbose)
 573                progress = start_progress(
 574                                from_stdin ? "Receiving objects" : "Indexing objects",
 575                                nr_objects);
 576        for (i = 0; i < nr_objects; i++) {
 577                struct object_entry *obj = &objects[i];
 578                void *data = unpack_raw_entry(obj, &delta->base);
 579                obj->real_type = obj->type;
 580                if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
 581                        nr_deltas++;
 582                        delta->obj_no = i;
 583                        delta++;
 584                } else
 585                        sha1_object(data, obj->size, obj->type, obj->idx.sha1);
 586                free(data);
 587                display_progress(progress, i+1);
 588        }
 589        objects[i].idx.offset = consumed_bytes;
 590        stop_progress(&progress);
 591
 592        /* Check pack integrity */
 593        flush();
 594        git_SHA1_Final(sha1, &input_ctx);
 595        if (hashcmp(fill(20), sha1))
 596                die("pack is corrupted (SHA1 mismatch)");
 597        use(20);
 598
 599        /* If input_fd is a file, we should have reached its end now. */
 600        if (fstat(input_fd, &st))
 601                die("cannot fstat packfile: %s", strerror(errno));
 602        if (S_ISREG(st.st_mode) &&
 603                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
 604                die("pack has junk at the end");
 605
 606        if (!nr_deltas)
 607                return;
 608
 609        /* Sort deltas by base SHA1/offset for fast searching */
 610        qsort(deltas, nr_deltas, sizeof(struct delta_entry),
 611              compare_delta_entry);
 612
 613        /*
 614         * Second pass:
 615         * - for all non-delta objects, look if it is used as a base for
 616         *   deltas;
 617         * - if used as a base, uncompress the object and apply all deltas,
 618         *   recursively checking if the resulting object is used as a base
 619         *   for some more deltas.
 620         */
 621        if (verbose)
 622                progress = start_progress("Resolving deltas", nr_deltas);
 623        for (i = 0; i < nr_objects; i++) {
 624                struct object_entry *obj = &objects[i];
 625                union delta_base base;
 626                int j, ref, ref_first, ref_last, ofs, ofs_first, ofs_last;
 627                struct base_data base_obj;
 628
 629                if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA)
 630                        continue;
 631                hashcpy(base.sha1, obj->idx.sha1);
 632                ref = !find_delta_children(&base, &ref_first, &ref_last);
 633                memset(&base, 0, sizeof(base));
 634                base.offset = obj->idx.offset;
 635                ofs = !find_delta_children(&base, &ofs_first, &ofs_last);
 636                if (!ref && !ofs)
 637                        continue;
 638                base_obj.data = get_data_from_pack(obj);
 639                base_obj.size = obj->size;
 640                base_obj.obj = obj;
 641                link_base_data(NULL, &base_obj);
 642
 643                if (ref)
 644                        for (j = ref_first; j <= ref_last; j++) {
 645                                struct object_entry *child = objects + deltas[j].obj_no;
 646                                if (child->real_type == OBJ_REF_DELTA)
 647                                        resolve_delta(child, &base_obj, obj->type);
 648                        }
 649                if (ofs)
 650                        for (j = ofs_first; j <= ofs_last; j++) {
 651                                struct object_entry *child = objects + deltas[j].obj_no;
 652                                if (child->real_type == OBJ_OFS_DELTA)
 653                                        resolve_delta(child, &base_obj, obj->type);
 654                        }
 655                unlink_base_data(&base_obj);
 656                display_progress(progress, nr_resolved_deltas);
 657        }
 658}
 659
 660static int write_compressed(struct sha1file *f, void *in, unsigned int size)
 661{
 662        z_stream stream;
 663        unsigned long maxsize;
 664        void *out;
 665
 666        memset(&stream, 0, sizeof(stream));
 667        deflateInit(&stream, zlib_compression_level);
 668        maxsize = deflateBound(&stream, size);
 669        out = xmalloc(maxsize);
 670
 671        /* Compress it */
 672        stream.next_in = in;
 673        stream.avail_in = size;
 674        stream.next_out = out;
 675        stream.avail_out = maxsize;
 676        while (deflate(&stream, Z_FINISH) == Z_OK);
 677        deflateEnd(&stream);
 678
 679        size = stream.total_out;
 680        sha1write(f, out, size);
 681        free(out);
 682        return size;
 683}
 684
 685static struct object_entry *append_obj_to_pack(struct sha1file *f,
 686                               const unsigned char *sha1, void *buf,
 687                               unsigned long size, enum object_type type)
 688{
 689        struct object_entry *obj = &objects[nr_objects++];
 690        unsigned char header[10];
 691        unsigned long s = size;
 692        int n = 0;
 693        unsigned char c = (type << 4) | (s & 15);
 694        s >>= 4;
 695        while (s) {
 696                header[n++] = c | 0x80;
 697                c = s & 0x7f;
 698                s >>= 7;
 699        }
 700        header[n++] = c;
 701        crc32_begin(f);
 702        sha1write(f, header, n);
 703        obj[0].size = size;
 704        obj[0].hdr_size = n;
 705        obj[0].type = type;
 706        obj[0].real_type = type;
 707        obj[1].idx.offset = obj[0].idx.offset + n;
 708        obj[1].idx.offset += write_compressed(f, buf, size);
 709        obj[0].idx.crc32 = crc32_end(f);
 710        sha1flush(f);
 711        hashcpy(obj->idx.sha1, sha1);
 712        return obj;
 713}
 714
 715static int delta_pos_compare(const void *_a, const void *_b)
 716{
 717        struct delta_entry *a = *(struct delta_entry **)_a;
 718        struct delta_entry *b = *(struct delta_entry **)_b;
 719        return a->obj_no - b->obj_no;
 720}
 721
 722static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
 723{
 724        struct delta_entry **sorted_by_pos;
 725        int i, n = 0;
 726
 727        /*
 728         * Since many unresolved deltas may well be themselves base objects
 729         * for more unresolved deltas, we really want to include the
 730         * smallest number of base objects that would cover as much delta
 731         * as possible by picking the
 732         * trunc deltas first, allowing for other deltas to resolve without
 733         * additional base objects.  Since most base objects are to be found
 734         * before deltas depending on them, a good heuristic is to start
 735         * resolving deltas in the same order as their position in the pack.
 736         */
 737        sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
 738        for (i = 0; i < nr_deltas; i++) {
 739                if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
 740                        continue;
 741                sorted_by_pos[n++] = &deltas[i];
 742        }
 743        qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
 744
 745        for (i = 0; i < n; i++) {
 746                struct delta_entry *d = sorted_by_pos[i];
 747                enum object_type type;
 748                int j, first, last;
 749                struct base_data base_obj;
 750
 751                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
 752                        continue;
 753                base_obj.data = read_sha1_file(d->base.sha1, &type, &base_obj.size);
 754                if (!base_obj.data)
 755                        continue;
 756
 757                if (check_sha1_signature(d->base.sha1, base_obj.data,
 758                                base_obj.size, typename(type)))
 759                        die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
 760                base_obj.obj = append_obj_to_pack(f, d->base.sha1,
 761                                        base_obj.data, base_obj.size, type);
 762                link_base_data(NULL, &base_obj);
 763
 764                find_delta_children(&d->base, &first, &last);
 765                for (j = first; j <= last; j++) {
 766                        struct object_entry *child = objects + deltas[j].obj_no;
 767                        if (child->real_type == OBJ_REF_DELTA)
 768                                resolve_delta(child, &base_obj, type);
 769                }
 770
 771                unlink_base_data(&base_obj);
 772                display_progress(progress, nr_resolved_deltas);
 773        }
 774        free(sorted_by_pos);
 775}
 776
 777static void final(const char *final_pack_name, const char *curr_pack_name,
 778                  const char *final_index_name, const char *curr_index_name,
 779                  const char *keep_name, const char *keep_msg,
 780                  unsigned char *sha1)
 781{
 782        const char *report = "pack";
 783        char name[PATH_MAX];
 784        int err;
 785
 786        if (!from_stdin) {
 787                close(input_fd);
 788        } else {
 789                fsync_or_die(output_fd, curr_pack_name);
 790                err = close(output_fd);
 791                if (err)
 792                        die("error while closing pack file: %s", strerror(errno));
 793                chmod(curr_pack_name, 0444);
 794        }
 795
 796        if (keep_msg) {
 797                int keep_fd, keep_msg_len = strlen(keep_msg);
 798                if (!keep_name) {
 799                        snprintf(name, sizeof(name), "%s/pack/pack-%s.keep",
 800                                 get_object_directory(), sha1_to_hex(sha1));
 801                        keep_name = name;
 802                }
 803                keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
 804                if (keep_fd < 0) {
 805                        if (errno != EEXIST)
 806                                die("cannot write keep file");
 807                } else {
 808                        if (keep_msg_len > 0) {
 809                                write_or_die(keep_fd, keep_msg, keep_msg_len);
 810                                write_or_die(keep_fd, "\n", 1);
 811                        }
 812                        if (close(keep_fd) != 0)
 813                                die("cannot write keep file");
 814                        report = "keep";
 815                }
 816        }
 817
 818        if (final_pack_name != curr_pack_name) {
 819                if (!final_pack_name) {
 820                        snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
 821                                 get_object_directory(), sha1_to_hex(sha1));
 822                        final_pack_name = name;
 823                }
 824                if (move_temp_to_file(curr_pack_name, final_pack_name))
 825                        die("cannot store pack file");
 826        }
 827
 828        chmod(curr_index_name, 0444);
 829        if (final_index_name != curr_index_name) {
 830                if (!final_index_name) {
 831                        snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
 832                                 get_object_directory(), sha1_to_hex(sha1));
 833                        final_index_name = name;
 834                }
 835                if (move_temp_to_file(curr_index_name, final_index_name))
 836                        die("cannot store index file");
 837        }
 838
 839        if (!from_stdin) {
 840                printf("%s\n", sha1_to_hex(sha1));
 841        } else {
 842                char buf[48];
 843                int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
 844                                   report, sha1_to_hex(sha1));
 845                write_or_die(1, buf, len);
 846
 847                /*
 848                 * Let's just mimic git-unpack-objects here and write
 849                 * the last part of the input buffer to stdout.
 850                 */
 851                while (input_len) {
 852                        err = xwrite(1, input_buffer + input_offset, input_len);
 853                        if (err <= 0)
 854                                break;
 855                        input_len -= err;
 856                        input_offset += err;
 857                }
 858        }
 859}
 860
 861static int git_index_pack_config(const char *k, const char *v, void *cb)
 862{
 863        if (!strcmp(k, "pack.indexversion")) {
 864                pack_idx_default_version = git_config_int(k, v);
 865                if (pack_idx_default_version > 2)
 866                        die("bad pack.indexversion=%"PRIu32,
 867                                pack_idx_default_version);
 868                return 0;
 869        }
 870        return git_default_config(k, v, cb);
 871}
 872
 873int main(int argc, char **argv)
 874{
 875        int i, fix_thin_pack = 0;
 876        char *curr_pack, *pack_name = NULL;
 877        char *curr_index, *index_name = NULL;
 878        const char *keep_name = NULL, *keep_msg = NULL;
 879        char *index_name_buf = NULL, *keep_name_buf = NULL;
 880        struct pack_idx_entry **idx_objects;
 881        unsigned char pack_sha1[20];
 882        int nongit = 0;
 883
 884        setup_git_directory_gently(&nongit);
 885        git_config(git_index_pack_config, NULL);
 886
 887        for (i = 1; i < argc; i++) {
 888                char *arg = argv[i];
 889
 890                if (*arg == '-') {
 891                        if (!strcmp(arg, "--stdin")) {
 892                                from_stdin = 1;
 893                        } else if (!strcmp(arg, "--fix-thin")) {
 894                                fix_thin_pack = 1;
 895                        } else if (!strcmp(arg, "--strict")) {
 896                                strict = 1;
 897                        } else if (!strcmp(arg, "--keep")) {
 898                                keep_msg = "";
 899                        } else if (!prefixcmp(arg, "--keep=")) {
 900                                keep_msg = arg + 7;
 901                        } else if (!prefixcmp(arg, "--pack_header=")) {
 902                                struct pack_header *hdr;
 903                                char *c;
 904
 905                                hdr = (struct pack_header *)input_buffer;
 906                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
 907                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
 908                                if (*c != ',')
 909                                        die("bad %s", arg);
 910                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
 911                                if (*c)
 912                                        die("bad %s", arg);
 913                                input_len = sizeof(*hdr);
 914                        } else if (!strcmp(arg, "-v")) {
 915                                verbose = 1;
 916                        } else if (!strcmp(arg, "-o")) {
 917                                if (index_name || (i+1) >= argc)
 918                                        usage(index_pack_usage);
 919                                index_name = argv[++i];
 920                        } else if (!prefixcmp(arg, "--index-version=")) {
 921                                char *c;
 922                                pack_idx_default_version = strtoul(arg + 16, &c, 10);
 923                                if (pack_idx_default_version > 2)
 924                                        die("bad %s", arg);
 925                                if (*c == ',')
 926                                        pack_idx_off32_limit = strtoul(c+1, &c, 0);
 927                                if (*c || pack_idx_off32_limit & 0x80000000)
 928                                        die("bad %s", arg);
 929                        } else
 930                                usage(index_pack_usage);
 931                        continue;
 932                }
 933
 934                if (pack_name)
 935                        usage(index_pack_usage);
 936                pack_name = arg;
 937        }
 938
 939        if (!pack_name && !from_stdin)
 940                usage(index_pack_usage);
 941        if (fix_thin_pack && !from_stdin)
 942                die("--fix-thin cannot be used without --stdin");
 943        if (!index_name && pack_name) {
 944                int len = strlen(pack_name);
 945                if (!has_extension(pack_name, ".pack"))
 946                        die("packfile name '%s' does not end with '.pack'",
 947                            pack_name);
 948                index_name_buf = xmalloc(len);
 949                memcpy(index_name_buf, pack_name, len - 5);
 950                strcpy(index_name_buf + len - 5, ".idx");
 951                index_name = index_name_buf;
 952        }
 953        if (keep_msg && !keep_name && pack_name) {
 954                int len = strlen(pack_name);
 955                if (!has_extension(pack_name, ".pack"))
 956                        die("packfile name '%s' does not end with '.pack'",
 957                            pack_name);
 958                keep_name_buf = xmalloc(len);
 959                memcpy(keep_name_buf, pack_name, len - 5);
 960                strcpy(keep_name_buf + len - 5, ".keep");
 961                keep_name = keep_name_buf;
 962        }
 963
 964        curr_pack = open_pack_file(pack_name);
 965        parse_pack_header();
 966        objects = xmalloc((nr_objects + 1) * sizeof(struct object_entry));
 967        deltas = xmalloc(nr_objects * sizeof(struct delta_entry));
 968        parse_pack_objects(pack_sha1);
 969        if (nr_deltas == nr_resolved_deltas) {
 970                stop_progress(&progress);
 971                /* Flush remaining pack final 20-byte SHA1. */
 972                flush();
 973        } else {
 974                if (fix_thin_pack) {
 975                        struct sha1file *f;
 976                        unsigned char read_sha1[20], tail_sha1[20];
 977                        char msg[48];
 978                        int nr_unresolved = nr_deltas - nr_resolved_deltas;
 979                        int nr_objects_initial = nr_objects;
 980                        if (nr_unresolved <= 0)
 981                                die("confusion beyond insanity");
 982                        objects = xrealloc(objects,
 983                                           (nr_objects + nr_unresolved + 1)
 984                                           * sizeof(*objects));
 985                        f = sha1fd(output_fd, curr_pack);
 986                        fix_unresolved_deltas(f, nr_unresolved);
 987                        sprintf(msg, "completed with %d local objects",
 988                                nr_objects - nr_objects_initial);
 989                        stop_progress_msg(&progress, msg);
 990                        sha1close(f, tail_sha1, 0);
 991                        hashcpy(read_sha1, pack_sha1);
 992                        fixup_pack_header_footer(output_fd, pack_sha1,
 993                                                 curr_pack, nr_objects,
 994                                                 read_sha1, consumed_bytes-20);
 995                        if (hashcmp(read_sha1, tail_sha1) != 0)
 996                                die("Unexpected tail checksum for %s "
 997                                    "(disk corruption?)", curr_pack);
 998                }
 999                if (nr_deltas != nr_resolved_deltas)
1000                        die("pack has %d unresolved deltas",
1001                            nr_deltas - nr_resolved_deltas);
1002        }
1003        free(deltas);
1004        if (strict)
1005                check_objects();
1006
1007        idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
1008        for (i = 0; i < nr_objects; i++)
1009                idx_objects[i] = &objects[i].idx;
1010        curr_index = write_idx_file(index_name, idx_objects, nr_objects, pack_sha1);
1011        free(idx_objects);
1012
1013        final(pack_name, curr_pack,
1014                index_name, curr_index,
1015                keep_name, keep_msg,
1016                pack_sha1);
1017        free(objects);
1018        free(index_name_buf);
1019        free(keep_name_buf);
1020        if (pack_name == NULL)
1021                free(curr_pack);
1022        if (index_name == NULL)
1023                free(curr_index);
1024
1025        return 0;
1026}