builtin / index-pack.con commit Merge branch 'lr/git-run-setup-gently' (22e91ba)
   1#include "builtin.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#include "exec_cmd.h"
  12#include "streaming.h"
  13#include "thread-utils.h"
  14
  15static const char index_pack_usage[] =
  16"git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
  17
  18struct object_entry {
  19        struct pack_idx_entry idx;
  20        unsigned long size;
  21        unsigned int hdr_size;
  22        enum object_type type;
  23        enum object_type real_type;
  24        unsigned delta_depth;
  25        int base_object_no;
  26};
  27
  28union delta_base {
  29        unsigned char sha1[20];
  30        off_t offset;
  31};
  32
  33struct base_data {
  34        struct base_data *base;
  35        struct base_data *child;
  36        struct object_entry *obj;
  37        void *data;
  38        unsigned long size;
  39        int ref_first, ref_last;
  40        int ofs_first, ofs_last;
  41};
  42
  43struct thread_local {
  44#ifndef NO_PTHREADS
  45        pthread_t thread;
  46#endif
  47        struct base_data *base_cache;
  48        size_t base_cache_used;
  49        int pack_fd;
  50};
  51
  52/*
  53 * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
  54 * to memcmp() only the first 20 bytes.
  55 */
  56#define UNION_BASE_SZ   20
  57
  58#define FLAG_LINK (1u<<20)
  59#define FLAG_CHECKED (1u<<21)
  60
  61struct delta_entry {
  62        union delta_base base;
  63        int obj_no;
  64};
  65
  66static struct object_entry *objects;
  67static struct delta_entry *deltas;
  68static struct thread_local nothread_data;
  69static int nr_objects;
  70static int nr_deltas;
  71static int nr_resolved_deltas;
  72static int nr_threads;
  73
  74static int from_stdin;
  75static int strict;
  76static int do_fsck_object;
  77static int verbose;
  78static int show_stat;
  79static int check_self_contained_and_connected;
  80
  81static struct progress *progress;
  82
  83/* We always read in 4kB chunks. */
  84static unsigned char input_buffer[4096];
  85static unsigned int input_offset, input_len;
  86static off_t consumed_bytes;
  87static unsigned deepest_delta;
  88static git_SHA_CTX input_ctx;
  89static uint32_t input_crc32;
  90static int input_fd, output_fd;
  91static const char *curr_pack;
  92
  93#ifndef NO_PTHREADS
  94
  95static struct thread_local *thread_data;
  96static int nr_dispatched;
  97static int threads_active;
  98
  99static pthread_mutex_t read_mutex;
 100#define read_lock()             lock_mutex(&read_mutex)
 101#define read_unlock()           unlock_mutex(&read_mutex)
 102
 103static pthread_mutex_t counter_mutex;
 104#define counter_lock()          lock_mutex(&counter_mutex)
 105#define counter_unlock()        unlock_mutex(&counter_mutex)
 106
 107static pthread_mutex_t work_mutex;
 108#define work_lock()             lock_mutex(&work_mutex)
 109#define work_unlock()           unlock_mutex(&work_mutex)
 110
 111static pthread_mutex_t deepest_delta_mutex;
 112#define deepest_delta_lock()    lock_mutex(&deepest_delta_mutex)
 113#define deepest_delta_unlock()  unlock_mutex(&deepest_delta_mutex)
 114
 115static pthread_key_t key;
 116
 117static inline void lock_mutex(pthread_mutex_t *mutex)
 118{
 119        if (threads_active)
 120                pthread_mutex_lock(mutex);
 121}
 122
 123static inline void unlock_mutex(pthread_mutex_t *mutex)
 124{
 125        if (threads_active)
 126                pthread_mutex_unlock(mutex);
 127}
 128
 129/*
 130 * Mutex and conditional variable can't be statically-initialized on Windows.
 131 */
 132static void init_thread(void)
 133{
 134        int i;
 135        init_recursive_mutex(&read_mutex);
 136        pthread_mutex_init(&counter_mutex, NULL);
 137        pthread_mutex_init(&work_mutex, NULL);
 138        if (show_stat)
 139                pthread_mutex_init(&deepest_delta_mutex, NULL);
 140        pthread_key_create(&key, NULL);
 141        thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 142        for (i = 0; i < nr_threads; i++) {
 143                thread_data[i].pack_fd = open(curr_pack, O_RDONLY);
 144                if (thread_data[i].pack_fd == -1)
 145                        die_errno(_("unable to open %s"), curr_pack);
 146        }
 147
 148        threads_active = 1;
 149}
 150
 151static void cleanup_thread(void)
 152{
 153        int i;
 154        if (!threads_active)
 155                return;
 156        threads_active = 0;
 157        pthread_mutex_destroy(&read_mutex);
 158        pthread_mutex_destroy(&counter_mutex);
 159        pthread_mutex_destroy(&work_mutex);
 160        if (show_stat)
 161                pthread_mutex_destroy(&deepest_delta_mutex);
 162        for (i = 0; i < nr_threads; i++)
 163                close(thread_data[i].pack_fd);
 164        pthread_key_delete(key);
 165        free(thread_data);
 166}
 167
 168#else
 169
 170#define read_lock()
 171#define read_unlock()
 172
 173#define counter_lock()
 174#define counter_unlock()
 175
 176#define work_lock()
 177#define work_unlock()
 178
 179#define deepest_delta_lock()
 180#define deepest_delta_unlock()
 181
 182#endif
 183
 184
 185static int mark_link(struct object *obj, int type, void *data)
 186{
 187        if (!obj)
 188                return -1;
 189
 190        if (type != OBJ_ANY && obj->type != type)
 191                die(_("object type mismatch at %s"), sha1_to_hex(obj->sha1));
 192
 193        obj->flags |= FLAG_LINK;
 194        return 0;
 195}
 196
 197/* The content of each linked object must have been checked
 198   or it must be already present in the object database */
 199static unsigned check_object(struct object *obj)
 200{
 201        if (!obj)
 202                return 0;
 203
 204        if (!(obj->flags & FLAG_LINK))
 205                return 0;
 206
 207        if (!(obj->flags & FLAG_CHECKED)) {
 208                unsigned long size;
 209                int type = sha1_object_info(obj->sha1, &size);
 210                if (type != obj->type || type <= 0)
 211                        die(_("object of unexpected type"));
 212                obj->flags |= FLAG_CHECKED;
 213                return 1;
 214        }
 215
 216        return 0;
 217}
 218
 219static unsigned check_objects(void)
 220{
 221        unsigned i, max, foreign_nr = 0;
 222
 223        max = get_max_object_index();
 224        for (i = 0; i < max; i++)
 225                foreign_nr += check_object(get_indexed_object(i));
 226        return foreign_nr;
 227}
 228
 229
 230/* Discard current buffer used content. */
 231static void flush(void)
 232{
 233        if (input_offset) {
 234                if (output_fd >= 0)
 235                        write_or_die(output_fd, input_buffer, input_offset);
 236                git_SHA1_Update(&input_ctx, input_buffer, input_offset);
 237                memmove(input_buffer, input_buffer + input_offset, input_len);
 238                input_offset = 0;
 239        }
 240}
 241
 242/*
 243 * Make sure at least "min" bytes are available in the buffer, and
 244 * return the pointer to the buffer.
 245 */
 246static void *fill(int min)
 247{
 248        if (min <= input_len)
 249                return input_buffer + input_offset;
 250        if (min > sizeof(input_buffer))
 251                die(Q_("cannot fill %d byte",
 252                       "cannot fill %d bytes",
 253                       min),
 254                    min);
 255        flush();
 256        do {
 257                ssize_t ret = xread(input_fd, input_buffer + input_len,
 258                                sizeof(input_buffer) - input_len);
 259                if (ret <= 0) {
 260                        if (!ret)
 261                                die(_("early EOF"));
 262                        die_errno(_("read error on input"));
 263                }
 264                input_len += ret;
 265                if (from_stdin)
 266                        display_throughput(progress, consumed_bytes + input_len);
 267        } while (input_len < min);
 268        return input_buffer;
 269}
 270
 271static void use(int bytes)
 272{
 273        if (bytes > input_len)
 274                die(_("used more bytes than were available"));
 275        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 276        input_len -= bytes;
 277        input_offset += bytes;
 278
 279        /* make sure off_t is sufficiently large not to wrap */
 280        if (signed_add_overflows(consumed_bytes, bytes))
 281                die(_("pack too large for current definition of off_t"));
 282        consumed_bytes += bytes;
 283}
 284
 285static const char *open_pack_file(const char *pack_name)
 286{
 287        if (from_stdin) {
 288                input_fd = 0;
 289                if (!pack_name) {
 290                        static char tmp_file[PATH_MAX];
 291                        output_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
 292                                                "pack/tmp_pack_XXXXXX");
 293                        pack_name = xstrdup(tmp_file);
 294                } else
 295                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 296                if (output_fd < 0)
 297                        die_errno(_("unable to create '%s'"), pack_name);
 298                nothread_data.pack_fd = output_fd;
 299        } else {
 300                input_fd = open(pack_name, O_RDONLY);
 301                if (input_fd < 0)
 302                        die_errno(_("cannot open packfile '%s'"), pack_name);
 303                output_fd = -1;
 304                nothread_data.pack_fd = input_fd;
 305        }
 306        git_SHA1_Init(&input_ctx);
 307        return pack_name;
 308}
 309
 310static void parse_pack_header(void)
 311{
 312        struct pack_header *hdr = fill(sizeof(struct pack_header));
 313
 314        /* Header consistency check */
 315        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 316                die(_("pack signature mismatch"));
 317        if (!pack_version_ok(hdr->hdr_version))
 318                die(_("pack version %"PRIu32" unsupported"),
 319                        ntohl(hdr->hdr_version));
 320
 321        nr_objects = ntohl(hdr->hdr_entries);
 322        use(sizeof(struct pack_header));
 323}
 324
 325static NORETURN void bad_object(unsigned long offset, const char *format,
 326                       ...) __attribute__((format (printf, 2, 3)));
 327
 328static NORETURN void bad_object(unsigned long offset, const char *format, ...)
 329{
 330        va_list params;
 331        char buf[1024];
 332
 333        va_start(params, format);
 334        vsnprintf(buf, sizeof(buf), format, params);
 335        va_end(params);
 336        die(_("pack has bad object at offset %lu: %s"), offset, buf);
 337}
 338
 339static inline struct thread_local *get_thread_data(void)
 340{
 341#ifndef NO_PTHREADS
 342        if (threads_active)
 343                return pthread_getspecific(key);
 344        assert(!threads_active &&
 345               "This should only be reached when all threads are gone");
 346#endif
 347        return &nothread_data;
 348}
 349
 350#ifndef NO_PTHREADS
 351static void set_thread_data(struct thread_local *data)
 352{
 353        if (threads_active)
 354                pthread_setspecific(key, data);
 355}
 356#endif
 357
 358static struct base_data *alloc_base_data(void)
 359{
 360        struct base_data *base = xmalloc(sizeof(struct base_data));
 361        memset(base, 0, sizeof(*base));
 362        base->ref_last = -1;
 363        base->ofs_last = -1;
 364        return base;
 365}
 366
 367static void free_base_data(struct base_data *c)
 368{
 369        if (c->data) {
 370                free(c->data);
 371                c->data = NULL;
 372                get_thread_data()->base_cache_used -= c->size;
 373        }
 374}
 375
 376static void prune_base_data(struct base_data *retain)
 377{
 378        struct base_data *b;
 379        struct thread_local *data = get_thread_data();
 380        for (b = data->base_cache;
 381             data->base_cache_used > delta_base_cache_limit && b;
 382             b = b->child) {
 383                if (b->data && b != retain)
 384                        free_base_data(b);
 385        }
 386}
 387
 388static void link_base_data(struct base_data *base, struct base_data *c)
 389{
 390        if (base)
 391                base->child = c;
 392        else
 393                get_thread_data()->base_cache = c;
 394
 395        c->base = base;
 396        c->child = NULL;
 397        if (c->data)
 398                get_thread_data()->base_cache_used += c->size;
 399        prune_base_data(c);
 400}
 401
 402static void unlink_base_data(struct base_data *c)
 403{
 404        struct base_data *base = c->base;
 405        if (base)
 406                base->child = NULL;
 407        else
 408                get_thread_data()->base_cache = NULL;
 409        free_base_data(c);
 410}
 411
 412static int is_delta_type(enum object_type type)
 413{
 414        return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 415}
 416
 417static void *unpack_entry_data(unsigned long offset, unsigned long size,
 418                               enum object_type type, unsigned char *sha1)
 419{
 420        static char fixed_buf[8192];
 421        int status;
 422        git_zstream stream;
 423        void *buf;
 424        git_SHA_CTX c;
 425        char hdr[32];
 426        int hdrlen;
 427
 428        if (!is_delta_type(type)) {
 429                hdrlen = sprintf(hdr, "%s %lu", typename(type), size) + 1;
 430                git_SHA1_Init(&c);
 431                git_SHA1_Update(&c, hdr, hdrlen);
 432        } else
 433                sha1 = NULL;
 434        if (type == OBJ_BLOB && size > big_file_threshold)
 435                buf = fixed_buf;
 436        else
 437                buf = xmalloc(size);
 438
 439        memset(&stream, 0, sizeof(stream));
 440        git_inflate_init(&stream);
 441        stream.next_out = buf;
 442        stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 443
 444        do {
 445                unsigned char *last_out = stream.next_out;
 446                stream.next_in = fill(1);
 447                stream.avail_in = input_len;
 448                status = git_inflate(&stream, 0);
 449                use(input_len - stream.avail_in);
 450                if (sha1)
 451                        git_SHA1_Update(&c, last_out, stream.next_out - last_out);
 452                if (buf == fixed_buf) {
 453                        stream.next_out = buf;
 454                        stream.avail_out = sizeof(fixed_buf);
 455                }
 456        } while (status == Z_OK);
 457        if (stream.total_out != size || status != Z_STREAM_END)
 458                bad_object(offset, _("inflate returned %d"), status);
 459        git_inflate_end(&stream);
 460        if (sha1)
 461                git_SHA1_Final(sha1, &c);
 462        return buf == fixed_buf ? NULL : buf;
 463}
 464
 465static void *unpack_raw_entry(struct object_entry *obj,
 466                              union delta_base *delta_base,
 467                              unsigned char *sha1)
 468{
 469        unsigned char *p;
 470        unsigned long size, c;
 471        off_t base_offset;
 472        unsigned shift;
 473        void *data;
 474
 475        obj->idx.offset = consumed_bytes;
 476        input_crc32 = crc32(0, NULL, 0);
 477
 478        p = fill(1);
 479        c = *p;
 480        use(1);
 481        obj->type = (c >> 4) & 7;
 482        size = (c & 15);
 483        shift = 4;
 484        while (c & 0x80) {
 485                p = fill(1);
 486                c = *p;
 487                use(1);
 488                size += (c & 0x7f) << shift;
 489                shift += 7;
 490        }
 491        obj->size = size;
 492
 493        switch (obj->type) {
 494        case OBJ_REF_DELTA:
 495                hashcpy(delta_base->sha1, fill(20));
 496                use(20);
 497                break;
 498        case OBJ_OFS_DELTA:
 499                memset(delta_base, 0, sizeof(*delta_base));
 500                p = fill(1);
 501                c = *p;
 502                use(1);
 503                base_offset = c & 127;
 504                while (c & 128) {
 505                        base_offset += 1;
 506                        if (!base_offset || MSB(base_offset, 7))
 507                                bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 508                        p = fill(1);
 509                        c = *p;
 510                        use(1);
 511                        base_offset = (base_offset << 7) + (c & 127);
 512                }
 513                delta_base->offset = obj->idx.offset - base_offset;
 514                if (delta_base->offset <= 0 || delta_base->offset >= obj->idx.offset)
 515                        bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 516                break;
 517        case OBJ_COMMIT:
 518        case OBJ_TREE:
 519        case OBJ_BLOB:
 520        case OBJ_TAG:
 521                break;
 522        default:
 523                bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 524        }
 525        obj->hdr_size = consumed_bytes - obj->idx.offset;
 526
 527        data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, sha1);
 528        obj->idx.crc32 = input_crc32;
 529        return data;
 530}
 531
 532static void *unpack_data(struct object_entry *obj,
 533                         int (*consume)(const unsigned char *, unsigned long, void *),
 534                         void *cb_data)
 535{
 536        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 537        unsigned long len = obj[1].idx.offset - from;
 538        unsigned char *data, *inbuf;
 539        git_zstream stream;
 540        int status;
 541
 542        data = xmalloc(consume ? 64*1024 : obj->size);
 543        inbuf = xmalloc((len < 64*1024) ? len : 64*1024);
 544
 545        memset(&stream, 0, sizeof(stream));
 546        git_inflate_init(&stream);
 547        stream.next_out = data;
 548        stream.avail_out = consume ? 64*1024 : obj->size;
 549
 550        do {
 551                ssize_t n = (len < 64*1024) ? len : 64*1024;
 552                n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 553                if (n < 0)
 554                        die_errno(_("cannot pread pack file"));
 555                if (!n)
 556                        die(Q_("premature end of pack file, %lu byte missing",
 557                               "premature end of pack file, %lu bytes missing",
 558                               len),
 559                            len);
 560                from += n;
 561                len -= n;
 562                stream.next_in = inbuf;
 563                stream.avail_in = n;
 564                if (!consume)
 565                        status = git_inflate(&stream, 0);
 566                else {
 567                        do {
 568                                status = git_inflate(&stream, 0);
 569                                if (consume(data, stream.next_out - data, cb_data)) {
 570                                        free(inbuf);
 571                                        free(data);
 572                                        return NULL;
 573                                }
 574                                stream.next_out = data;
 575                                stream.avail_out = 64*1024;
 576                        } while (status == Z_OK && stream.avail_in);
 577                }
 578        } while (len && status == Z_OK && !stream.avail_in);
 579
 580        /* This has been inflated OK when first encountered, so... */
 581        if (status != Z_STREAM_END || stream.total_out != obj->size)
 582                die(_("serious inflate inconsistency"));
 583
 584        git_inflate_end(&stream);
 585        free(inbuf);
 586        if (consume) {
 587                free(data);
 588                data = NULL;
 589        }
 590        return data;
 591}
 592
 593static void *get_data_from_pack(struct object_entry *obj)
 594{
 595        return unpack_data(obj, NULL, NULL);
 596}
 597
 598static int compare_delta_bases(const union delta_base *base1,
 599                               const union delta_base *base2,
 600                               enum object_type type1,
 601                               enum object_type type2)
 602{
 603        int cmp = type1 - type2;
 604        if (cmp)
 605                return cmp;
 606        return memcmp(base1, base2, UNION_BASE_SZ);
 607}
 608
 609static int find_delta(const union delta_base *base, enum object_type type)
 610{
 611        int first = 0, last = nr_deltas;
 612
 613        while (first < last) {
 614                int next = (first + last) / 2;
 615                struct delta_entry *delta = &deltas[next];
 616                int cmp;
 617
 618                cmp = compare_delta_bases(base, &delta->base,
 619                                          type, objects[delta->obj_no].type);
 620                if (!cmp)
 621                        return next;
 622                if (cmp < 0) {
 623                        last = next;
 624                        continue;
 625                }
 626                first = next+1;
 627        }
 628        return -first-1;
 629}
 630
 631static void find_delta_children(const union delta_base *base,
 632                                int *first_index, int *last_index,
 633                                enum object_type type)
 634{
 635        int first = find_delta(base, type);
 636        int last = first;
 637        int end = nr_deltas - 1;
 638
 639        if (first < 0) {
 640                *first_index = 0;
 641                *last_index = -1;
 642                return;
 643        }
 644        while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
 645                --first;
 646        while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
 647                ++last;
 648        *first_index = first;
 649        *last_index = last;
 650}
 651
 652struct compare_data {
 653        struct object_entry *entry;
 654        struct git_istream *st;
 655        unsigned char *buf;
 656        unsigned long buf_size;
 657};
 658
 659static int compare_objects(const unsigned char *buf, unsigned long size,
 660                           void *cb_data)
 661{
 662        struct compare_data *data = cb_data;
 663
 664        if (data->buf_size < size) {
 665                free(data->buf);
 666                data->buf = xmalloc(size);
 667                data->buf_size = size;
 668        }
 669
 670        while (size) {
 671                ssize_t len = read_istream(data->st, data->buf, size);
 672                if (len == 0)
 673                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 674                            sha1_to_hex(data->entry->idx.sha1));
 675                if (len < 0)
 676                        die(_("unable to read %s"),
 677                            sha1_to_hex(data->entry->idx.sha1));
 678                if (memcmp(buf, data->buf, len))
 679                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 680                            sha1_to_hex(data->entry->idx.sha1));
 681                size -= len;
 682                buf += len;
 683        }
 684        return 0;
 685}
 686
 687static int check_collison(struct object_entry *entry)
 688{
 689        struct compare_data data;
 690        enum object_type type;
 691        unsigned long size;
 692
 693        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 694                return -1;
 695
 696        memset(&data, 0, sizeof(data));
 697        data.entry = entry;
 698        data.st = open_istream(entry->idx.sha1, &type, &size, NULL);
 699        if (!data.st)
 700                return -1;
 701        if (size != entry->size || type != entry->type)
 702                die(_("SHA1 COLLISION FOUND WITH %s !"),
 703                    sha1_to_hex(entry->idx.sha1));
 704        unpack_data(entry, compare_objects, &data);
 705        close_istream(data.st);
 706        free(data.buf);
 707        return 0;
 708}
 709
 710static void sha1_object(const void *data, struct object_entry *obj_entry,
 711                        unsigned long size, enum object_type type,
 712                        const unsigned char *sha1)
 713{
 714        void *new_data = NULL;
 715        int collision_test_needed;
 716
 717        assert(data || obj_entry);
 718
 719        read_lock();
 720        collision_test_needed = has_sha1_file(sha1);
 721        read_unlock();
 722
 723        if (collision_test_needed && !data) {
 724                read_lock();
 725                if (!check_collison(obj_entry))
 726                        collision_test_needed = 0;
 727                read_unlock();
 728        }
 729        if (collision_test_needed) {
 730                void *has_data;
 731                enum object_type has_type;
 732                unsigned long has_size;
 733                read_lock();
 734                has_type = sha1_object_info(sha1, &has_size);
 735                if (has_type != type || has_size != size)
 736                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 737                has_data = read_sha1_file(sha1, &has_type, &has_size);
 738                read_unlock();
 739                if (!data)
 740                        data = new_data = get_data_from_pack(obj_entry);
 741                if (!has_data)
 742                        die(_("cannot read existing object %s"), sha1_to_hex(sha1));
 743                if (size != has_size || type != has_type ||
 744                    memcmp(data, has_data, size) != 0)
 745                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 746                free(has_data);
 747        }
 748
 749        if (strict) {
 750                read_lock();
 751                if (type == OBJ_BLOB) {
 752                        struct blob *blob = lookup_blob(sha1);
 753                        if (blob)
 754                                blob->object.flags |= FLAG_CHECKED;
 755                        else
 756                                die(_("invalid blob object %s"), sha1_to_hex(sha1));
 757                } else {
 758                        struct object *obj;
 759                        int eaten;
 760                        void *buf = (void *) data;
 761
 762                        assert(data && "data can only be NULL for large _blobs_");
 763
 764                        /*
 765                         * we do not need to free the memory here, as the
 766                         * buf is deleted by the caller.
 767                         */
 768                        obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 769                        if (!obj)
 770                                die(_("invalid %s"), typename(type));
 771                        if (do_fsck_object &&
 772                            fsck_object(obj, 1, fsck_error_function))
 773                                die(_("Error in object"));
 774                        if (fsck_walk(obj, mark_link, NULL))
 775                                die(_("Not all child objects of %s are reachable"), sha1_to_hex(obj->sha1));
 776
 777                        if (obj->type == OBJ_TREE) {
 778                                struct tree *item = (struct tree *) obj;
 779                                item->buffer = NULL;
 780                                obj->parsed = 0;
 781                        }
 782                        if (obj->type == OBJ_COMMIT) {
 783                                struct commit *commit = (struct commit *) obj;
 784                                commit->buffer = NULL;
 785                        }
 786                        obj->flags |= FLAG_CHECKED;
 787                }
 788                read_unlock();
 789        }
 790
 791        free(new_data);
 792}
 793
 794/*
 795 * This function is part of find_unresolved_deltas(). There are two
 796 * walkers going in the opposite ways.
 797 *
 798 * The first one in find_unresolved_deltas() traverses down from
 799 * parent node to children, deflating nodes along the way. However,
 800 * memory for deflated nodes is limited by delta_base_cache_limit, so
 801 * at some point parent node's deflated content may be freed.
 802 *
 803 * The second walker is this function, which goes from current node up
 804 * to top parent if necessary to deflate the node. In normal
 805 * situation, its parent node would be already deflated, so it just
 806 * needs to apply delta.
 807 *
 808 * In the worst case scenario, parent node is no longer deflated because
 809 * we're running out of delta_base_cache_limit; we need to re-deflate
 810 * parents, possibly up to the top base.
 811 *
 812 * All deflated objects here are subject to be freed if we exceed
 813 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 814 * just need to make sure the last node is not freed.
 815 */
 816static void *get_base_data(struct base_data *c)
 817{
 818        if (!c->data) {
 819                struct object_entry *obj = c->obj;
 820                struct base_data **delta = NULL;
 821                int delta_nr = 0, delta_alloc = 0;
 822
 823                while (is_delta_type(c->obj->type) && !c->data) {
 824                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 825                        delta[delta_nr++] = c;
 826                        c = c->base;
 827                }
 828                if (!delta_nr) {
 829                        c->data = get_data_from_pack(obj);
 830                        c->size = obj->size;
 831                        get_thread_data()->base_cache_used += c->size;
 832                        prune_base_data(c);
 833                }
 834                for (; delta_nr > 0; delta_nr--) {
 835                        void *base, *raw;
 836                        c = delta[delta_nr - 1];
 837                        obj = c->obj;
 838                        base = get_base_data(c->base);
 839                        raw = get_data_from_pack(obj);
 840                        c->data = patch_delta(
 841                                base, c->base->size,
 842                                raw, obj->size,
 843                                &c->size);
 844                        free(raw);
 845                        if (!c->data)
 846                                bad_object(obj->idx.offset, _("failed to apply delta"));
 847                        get_thread_data()->base_cache_used += c->size;
 848                        prune_base_data(c);
 849                }
 850                free(delta);
 851        }
 852        return c->data;
 853}
 854
 855static void resolve_delta(struct object_entry *delta_obj,
 856                          struct base_data *base, struct base_data *result)
 857{
 858        void *base_data, *delta_data;
 859
 860        delta_obj->real_type = base->obj->real_type;
 861        if (show_stat) {
 862                delta_obj->delta_depth = base->obj->delta_depth + 1;
 863                deepest_delta_lock();
 864                if (deepest_delta < delta_obj->delta_depth)
 865                        deepest_delta = delta_obj->delta_depth;
 866                deepest_delta_unlock();
 867        }
 868        delta_obj->base_object_no = base->obj - objects;
 869        delta_data = get_data_from_pack(delta_obj);
 870        base_data = get_base_data(base);
 871        result->obj = delta_obj;
 872        result->data = patch_delta(base_data, base->size,
 873                                   delta_data, delta_obj->size, &result->size);
 874        free(delta_data);
 875        if (!result->data)
 876                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 877        hash_sha1_file(result->data, result->size,
 878                       typename(delta_obj->real_type), delta_obj->idx.sha1);
 879        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 880                    delta_obj->idx.sha1);
 881        counter_lock();
 882        nr_resolved_deltas++;
 883        counter_unlock();
 884}
 885
 886static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 887                                                  struct base_data *prev_base)
 888{
 889        if (base->ref_last == -1 && base->ofs_last == -1) {
 890                union delta_base base_spec;
 891
 892                hashcpy(base_spec.sha1, base->obj->idx.sha1);
 893                find_delta_children(&base_spec,
 894                                    &base->ref_first, &base->ref_last, OBJ_REF_DELTA);
 895
 896                memset(&base_spec, 0, sizeof(base_spec));
 897                base_spec.offset = base->obj->idx.offset;
 898                find_delta_children(&base_spec,
 899                                    &base->ofs_first, &base->ofs_last, OBJ_OFS_DELTA);
 900
 901                if (base->ref_last == -1 && base->ofs_last == -1) {
 902                        free(base->data);
 903                        return NULL;
 904                }
 905
 906                link_base_data(prev_base, base);
 907        }
 908
 909        if (base->ref_first <= base->ref_last) {
 910                struct object_entry *child = objects + deltas[base->ref_first].obj_no;
 911                struct base_data *result = alloc_base_data();
 912
 913                assert(child->real_type == OBJ_REF_DELTA);
 914                resolve_delta(child, base, result);
 915                if (base->ref_first == base->ref_last && base->ofs_last == -1)
 916                        free_base_data(base);
 917
 918                base->ref_first++;
 919                return result;
 920        }
 921
 922        if (base->ofs_first <= base->ofs_last) {
 923                struct object_entry *child = objects + deltas[base->ofs_first].obj_no;
 924                struct base_data *result = alloc_base_data();
 925
 926                assert(child->real_type == OBJ_OFS_DELTA);
 927                resolve_delta(child, base, result);
 928                if (base->ofs_first == base->ofs_last)
 929                        free_base_data(base);
 930
 931                base->ofs_first++;
 932                return result;
 933        }
 934
 935        unlink_base_data(base);
 936        return NULL;
 937}
 938
 939static void find_unresolved_deltas(struct base_data *base)
 940{
 941        struct base_data *new_base, *prev_base = NULL;
 942        for (;;) {
 943                new_base = find_unresolved_deltas_1(base, prev_base);
 944
 945                if (new_base) {
 946                        prev_base = base;
 947                        base = new_base;
 948                } else {
 949                        free(base);
 950                        base = prev_base;
 951                        if (!base)
 952                                return;
 953                        prev_base = base->base;
 954                }
 955        }
 956}
 957
 958static int compare_delta_entry(const void *a, const void *b)
 959{
 960        const struct delta_entry *delta_a = a;
 961        const struct delta_entry *delta_b = b;
 962
 963        /* group by type (ref vs ofs) and then by value (sha-1 or offset) */
 964        return compare_delta_bases(&delta_a->base, &delta_b->base,
 965                                   objects[delta_a->obj_no].type,
 966                                   objects[delta_b->obj_no].type);
 967}
 968
 969static void resolve_base(struct object_entry *obj)
 970{
 971        struct base_data *base_obj = alloc_base_data();
 972        base_obj->obj = obj;
 973        base_obj->data = NULL;
 974        find_unresolved_deltas(base_obj);
 975}
 976
 977#ifndef NO_PTHREADS
 978static void *threaded_second_pass(void *data)
 979{
 980        set_thread_data(data);
 981        for (;;) {
 982                int i;
 983                counter_lock();
 984                display_progress(progress, nr_resolved_deltas);
 985                counter_unlock();
 986                work_lock();
 987                while (nr_dispatched < nr_objects &&
 988                       is_delta_type(objects[nr_dispatched].type))
 989                        nr_dispatched++;
 990                if (nr_dispatched >= nr_objects) {
 991                        work_unlock();
 992                        break;
 993                }
 994                i = nr_dispatched++;
 995                work_unlock();
 996
 997                resolve_base(&objects[i]);
 998        }
 999        return NULL;
1000}
1001#endif
1002
1003/*
1004 * First pass:
1005 * - find locations of all objects;
1006 * - calculate SHA1 of all non-delta objects;
1007 * - remember base (SHA1 or offset) for all deltas.
1008 */
1009static void parse_pack_objects(unsigned char *sha1)
1010{
1011        int i, nr_delays = 0;
1012        struct delta_entry *delta = deltas;
1013        struct stat st;
1014
1015        if (verbose)
1016                progress = start_progress(
1017                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1018                                nr_objects);
1019        for (i = 0; i < nr_objects; i++) {
1020                struct object_entry *obj = &objects[i];
1021                void *data = unpack_raw_entry(obj, &delta->base, obj->idx.sha1);
1022                obj->real_type = obj->type;
1023                if (is_delta_type(obj->type)) {
1024                        nr_deltas++;
1025                        delta->obj_no = i;
1026                        delta++;
1027                } else if (!data) {
1028                        /* large blobs, check later */
1029                        obj->real_type = OBJ_BAD;
1030                        nr_delays++;
1031                } else
1032                        sha1_object(data, NULL, obj->size, obj->type, obj->idx.sha1);
1033                free(data);
1034                display_progress(progress, i+1);
1035        }
1036        objects[i].idx.offset = consumed_bytes;
1037        stop_progress(&progress);
1038
1039        /* Check pack integrity */
1040        flush();
1041        git_SHA1_Final(sha1, &input_ctx);
1042        if (hashcmp(fill(20), sha1))
1043                die(_("pack is corrupted (SHA1 mismatch)"));
1044        use(20);
1045
1046        /* If input_fd is a file, we should have reached its end now. */
1047        if (fstat(input_fd, &st))
1048                die_errno(_("cannot fstat packfile"));
1049        if (S_ISREG(st.st_mode) &&
1050                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1051                die(_("pack has junk at the end"));
1052
1053        for (i = 0; i < nr_objects; i++) {
1054                struct object_entry *obj = &objects[i];
1055                if (obj->real_type != OBJ_BAD)
1056                        continue;
1057                obj->real_type = obj->type;
1058                sha1_object(NULL, obj, obj->size, obj->type, obj->idx.sha1);
1059                nr_delays--;
1060        }
1061        if (nr_delays)
1062                die(_("confusion beyond insanity in parse_pack_objects()"));
1063}
1064
1065/*
1066 * Second pass:
1067 * - for all non-delta objects, look if it is used as a base for
1068 *   deltas;
1069 * - if used as a base, uncompress the object and apply all deltas,
1070 *   recursively checking if the resulting object is used as a base
1071 *   for some more deltas.
1072 */
1073static void resolve_deltas(void)
1074{
1075        int i;
1076
1077        if (!nr_deltas)
1078                return;
1079
1080        /* Sort deltas by base SHA1/offset for fast searching */
1081        qsort(deltas, nr_deltas, sizeof(struct delta_entry),
1082              compare_delta_entry);
1083
1084        if (verbose)
1085                progress = start_progress(_("Resolving deltas"), nr_deltas);
1086
1087#ifndef NO_PTHREADS
1088        nr_dispatched = 0;
1089        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1090                init_thread();
1091                for (i = 0; i < nr_threads; i++) {
1092                        int ret = pthread_create(&thread_data[i].thread, NULL,
1093                                                 threaded_second_pass, thread_data + i);
1094                        if (ret)
1095                                die(_("unable to create thread: %s"),
1096                                    strerror(ret));
1097                }
1098                for (i = 0; i < nr_threads; i++)
1099                        pthread_join(thread_data[i].thread, NULL);
1100                cleanup_thread();
1101                return;
1102        }
1103#endif
1104
1105        for (i = 0; i < nr_objects; i++) {
1106                struct object_entry *obj = &objects[i];
1107
1108                if (is_delta_type(obj->type))
1109                        continue;
1110                resolve_base(obj);
1111                display_progress(progress, nr_resolved_deltas);
1112        }
1113}
1114
1115/*
1116 * Third pass:
1117 * - append objects to convert thin pack to full pack if required
1118 * - write the final 20-byte SHA-1
1119 */
1120static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved);
1121static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
1122{
1123        if (nr_deltas == nr_resolved_deltas) {
1124                stop_progress(&progress);
1125                /* Flush remaining pack final 20-byte SHA1. */
1126                flush();
1127                return;
1128        }
1129
1130        if (fix_thin_pack) {
1131                struct sha1file *f;
1132                unsigned char read_sha1[20], tail_sha1[20];
1133                struct strbuf msg = STRBUF_INIT;
1134                int nr_unresolved = nr_deltas - nr_resolved_deltas;
1135                int nr_objects_initial = nr_objects;
1136                if (nr_unresolved <= 0)
1137                        die(_("confusion beyond insanity"));
1138                objects = xrealloc(objects,
1139                                   (nr_objects + nr_unresolved + 1)
1140                                   * sizeof(*objects));
1141                memset(objects + nr_objects + 1, 0,
1142                       nr_unresolved * sizeof(*objects));
1143                f = sha1fd(output_fd, curr_pack);
1144                fix_unresolved_deltas(f, nr_unresolved);
1145                strbuf_addf(&msg, _("completed with %d local objects"),
1146                            nr_objects - nr_objects_initial);
1147                stop_progress_msg(&progress, msg.buf);
1148                strbuf_release(&msg);
1149                sha1close(f, tail_sha1, 0);
1150                hashcpy(read_sha1, pack_sha1);
1151                fixup_pack_header_footer(output_fd, pack_sha1,
1152                                         curr_pack, nr_objects,
1153                                         read_sha1, consumed_bytes-20);
1154                if (hashcmp(read_sha1, tail_sha1) != 0)
1155                        die(_("Unexpected tail checksum for %s "
1156                              "(disk corruption?)"), curr_pack);
1157        }
1158        if (nr_deltas != nr_resolved_deltas)
1159                die(Q_("pack has %d unresolved delta",
1160                       "pack has %d unresolved deltas",
1161                       nr_deltas - nr_resolved_deltas),
1162                    nr_deltas - nr_resolved_deltas);
1163}
1164
1165static int write_compressed(struct sha1file *f, void *in, unsigned int size)
1166{
1167        git_zstream stream;
1168        int status;
1169        unsigned char outbuf[4096];
1170
1171        memset(&stream, 0, sizeof(stream));
1172        git_deflate_init(&stream, zlib_compression_level);
1173        stream.next_in = in;
1174        stream.avail_in = size;
1175
1176        do {
1177                stream.next_out = outbuf;
1178                stream.avail_out = sizeof(outbuf);
1179                status = git_deflate(&stream, Z_FINISH);
1180                sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
1181        } while (status == Z_OK);
1182
1183        if (status != Z_STREAM_END)
1184                die(_("unable to deflate appended object (%d)"), status);
1185        size = stream.total_out;
1186        git_deflate_end(&stream);
1187        return size;
1188}
1189
1190static struct object_entry *append_obj_to_pack(struct sha1file *f,
1191                               const unsigned char *sha1, void *buf,
1192                               unsigned long size, enum object_type type)
1193{
1194        struct object_entry *obj = &objects[nr_objects++];
1195        unsigned char header[10];
1196        unsigned long s = size;
1197        int n = 0;
1198        unsigned char c = (type << 4) | (s & 15);
1199        s >>= 4;
1200        while (s) {
1201                header[n++] = c | 0x80;
1202                c = s & 0x7f;
1203                s >>= 7;
1204        }
1205        header[n++] = c;
1206        crc32_begin(f);
1207        sha1write(f, header, n);
1208        obj[0].size = size;
1209        obj[0].hdr_size = n;
1210        obj[0].type = type;
1211        obj[0].real_type = type;
1212        obj[1].idx.offset = obj[0].idx.offset + n;
1213        obj[1].idx.offset += write_compressed(f, buf, size);
1214        obj[0].idx.crc32 = crc32_end(f);
1215        sha1flush(f);
1216        hashcpy(obj->idx.sha1, sha1);
1217        return obj;
1218}
1219
1220static int delta_pos_compare(const void *_a, const void *_b)
1221{
1222        struct delta_entry *a = *(struct delta_entry **)_a;
1223        struct delta_entry *b = *(struct delta_entry **)_b;
1224        return a->obj_no - b->obj_no;
1225}
1226
1227static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
1228{
1229        struct delta_entry **sorted_by_pos;
1230        int i, n = 0;
1231
1232        /*
1233         * Since many unresolved deltas may well be themselves base objects
1234         * for more unresolved deltas, we really want to include the
1235         * smallest number of base objects that would cover as much delta
1236         * as possible by picking the
1237         * trunc deltas first, allowing for other deltas to resolve without
1238         * additional base objects.  Since most base objects are to be found
1239         * before deltas depending on them, a good heuristic is to start
1240         * resolving deltas in the same order as their position in the pack.
1241         */
1242        sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
1243        for (i = 0; i < nr_deltas; i++) {
1244                if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
1245                        continue;
1246                sorted_by_pos[n++] = &deltas[i];
1247        }
1248        qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
1249
1250        for (i = 0; i < n; i++) {
1251                struct delta_entry *d = sorted_by_pos[i];
1252                enum object_type type;
1253                struct base_data *base_obj = alloc_base_data();
1254
1255                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1256                        continue;
1257                base_obj->data = read_sha1_file(d->base.sha1, &type, &base_obj->size);
1258                if (!base_obj->data)
1259                        continue;
1260
1261                if (check_sha1_signature(d->base.sha1, base_obj->data,
1262                                base_obj->size, typename(type)))
1263                        die(_("local object %s is corrupt"), sha1_to_hex(d->base.sha1));
1264                base_obj->obj = append_obj_to_pack(f, d->base.sha1,
1265                                        base_obj->data, base_obj->size, type);
1266                find_unresolved_deltas(base_obj);
1267                display_progress(progress, nr_resolved_deltas);
1268        }
1269        free(sorted_by_pos);
1270}
1271
1272static void final(const char *final_pack_name, const char *curr_pack_name,
1273                  const char *final_index_name, const char *curr_index_name,
1274                  const char *keep_name, const char *keep_msg,
1275                  unsigned char *sha1)
1276{
1277        const char *report = "pack";
1278        char name[PATH_MAX];
1279        int err;
1280
1281        if (!from_stdin) {
1282                close(input_fd);
1283        } else {
1284                fsync_or_die(output_fd, curr_pack_name);
1285                err = close(output_fd);
1286                if (err)
1287                        die_errno(_("error while closing pack file"));
1288        }
1289
1290        if (keep_msg) {
1291                int keep_fd, keep_msg_len = strlen(keep_msg);
1292
1293                if (!keep_name)
1294                        keep_fd = odb_pack_keep(name, sizeof(name), sha1);
1295                else
1296                        keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
1297
1298                if (keep_fd < 0) {
1299                        if (errno != EEXIST)
1300                                die_errno(_("cannot write keep file '%s'"),
1301                                          keep_name ? keep_name : name);
1302                } else {
1303                        if (keep_msg_len > 0) {
1304                                write_or_die(keep_fd, keep_msg, keep_msg_len);
1305                                write_or_die(keep_fd, "\n", 1);
1306                        }
1307                        if (close(keep_fd) != 0)
1308                                die_errno(_("cannot close written keep file '%s'"),
1309                                          keep_name ? keep_name : name);
1310                        report = "keep";
1311                }
1312        }
1313
1314        if (final_pack_name != curr_pack_name) {
1315                if (!final_pack_name) {
1316                        snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
1317                                 get_object_directory(), sha1_to_hex(sha1));
1318                        final_pack_name = name;
1319                }
1320                if (move_temp_to_file(curr_pack_name, final_pack_name))
1321                        die(_("cannot store pack file"));
1322        } else if (from_stdin)
1323                chmod(final_pack_name, 0444);
1324
1325        if (final_index_name != curr_index_name) {
1326                if (!final_index_name) {
1327                        snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
1328                                 get_object_directory(), sha1_to_hex(sha1));
1329                        final_index_name = name;
1330                }
1331                if (move_temp_to_file(curr_index_name, final_index_name))
1332                        die(_("cannot store index file"));
1333        } else
1334                chmod(final_index_name, 0444);
1335
1336        if (!from_stdin) {
1337                printf("%s\n", sha1_to_hex(sha1));
1338        } else {
1339                char buf[48];
1340                int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
1341                                   report, sha1_to_hex(sha1));
1342                write_or_die(1, buf, len);
1343
1344                /*
1345                 * Let's just mimic git-unpack-objects here and write
1346                 * the last part of the input buffer to stdout.
1347                 */
1348                while (input_len) {
1349                        err = xwrite(1, input_buffer + input_offset, input_len);
1350                        if (err <= 0)
1351                                break;
1352                        input_len -= err;
1353                        input_offset += err;
1354                }
1355        }
1356}
1357
1358static int git_index_pack_config(const char *k, const char *v, void *cb)
1359{
1360        struct pack_idx_option *opts = cb;
1361
1362        if (!strcmp(k, "pack.indexversion")) {
1363                opts->version = git_config_int(k, v);
1364                if (opts->version > 2)
1365                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1366                return 0;
1367        }
1368        if (!strcmp(k, "pack.threads")) {
1369                nr_threads = git_config_int(k, v);
1370                if (nr_threads < 0)
1371                        die(_("invalid number of threads specified (%d)"),
1372                            nr_threads);
1373#ifdef NO_PTHREADS
1374                if (nr_threads != 1)
1375                        warning(_("no threads support, ignoring %s"), k);
1376                nr_threads = 1;
1377#endif
1378                return 0;
1379        }
1380        return git_default_config(k, v, cb);
1381}
1382
1383static int cmp_uint32(const void *a_, const void *b_)
1384{
1385        uint32_t a = *((uint32_t *)a_);
1386        uint32_t b = *((uint32_t *)b_);
1387
1388        return (a < b) ? -1 : (a != b);
1389}
1390
1391static void read_v2_anomalous_offsets(struct packed_git *p,
1392                                      struct pack_idx_option *opts)
1393{
1394        const uint32_t *idx1, *idx2;
1395        uint32_t i;
1396
1397        /* The address of the 4-byte offset table */
1398        idx1 = (((const uint32_t *)p->index_data)
1399                + 2 /* 8-byte header */
1400                + 256 /* fan out */
1401                + 5 * p->num_objects /* 20-byte SHA-1 table */
1402                + p->num_objects /* CRC32 table */
1403                );
1404
1405        /* The address of the 8-byte offset table */
1406        idx2 = idx1 + p->num_objects;
1407
1408        for (i = 0; i < p->num_objects; i++) {
1409                uint32_t off = ntohl(idx1[i]);
1410                if (!(off & 0x80000000))
1411                        continue;
1412                off = off & 0x7fffffff;
1413                if (idx2[off * 2])
1414                        continue;
1415                /*
1416                 * The real offset is ntohl(idx2[off * 2]) in high 4
1417                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1418                 * octets.  But idx2[off * 2] is Zero!!!
1419                 */
1420                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1421                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1422        }
1423
1424        if (1 < opts->anomaly_nr)
1425                qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
1426}
1427
1428static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1429{
1430        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1431
1432        if (!p)
1433                die(_("Cannot open existing pack file '%s'"), pack_name);
1434        if (open_pack_index(p))
1435                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1436
1437        /* Read the attributes from the existing idx file */
1438        opts->version = p->index_version;
1439
1440        if (opts->version == 2)
1441                read_v2_anomalous_offsets(p, opts);
1442
1443        /*
1444         * Get rid of the idx file as we do not need it anymore.
1445         * NEEDSWORK: extract this bit from free_pack_by_name() in
1446         * sha1_file.c, perhaps?  It shouldn't matter very much as we
1447         * know we haven't installed this pack (hence we never have
1448         * read anything from it).
1449         */
1450        close_pack_index(p);
1451        free(p);
1452}
1453
1454static void show_pack_info(int stat_only)
1455{
1456        int i, baseobjects = nr_objects - nr_deltas;
1457        unsigned long *chain_histogram = NULL;
1458
1459        if (deepest_delta)
1460                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1461
1462        for (i = 0; i < nr_objects; i++) {
1463                struct object_entry *obj = &objects[i];
1464
1465                if (is_delta_type(obj->type))
1466                        chain_histogram[obj->delta_depth - 1]++;
1467                if (stat_only)
1468                        continue;
1469                printf("%s %-6s %lu %lu %"PRIuMAX,
1470                       sha1_to_hex(obj->idx.sha1),
1471                       typename(obj->real_type), obj->size,
1472                       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1473                       (uintmax_t)obj->idx.offset);
1474                if (is_delta_type(obj->type)) {
1475                        struct object_entry *bobj = &objects[obj->base_object_no];
1476                        printf(" %u %s", obj->delta_depth, sha1_to_hex(bobj->idx.sha1));
1477                }
1478                putchar('\n');
1479        }
1480
1481        if (baseobjects)
1482                printf_ln(Q_("non delta: %d object",
1483                             "non delta: %d objects",
1484                             baseobjects),
1485                          baseobjects);
1486        for (i = 0; i < deepest_delta; i++) {
1487                if (!chain_histogram[i])
1488                        continue;
1489                printf_ln(Q_("chain length = %d: %lu object",
1490                             "chain length = %d: %lu objects",
1491                             chain_histogram[i]),
1492                          i + 1,
1493                          chain_histogram[i]);
1494        }
1495}
1496
1497int cmd_index_pack(int argc, const char **argv, const char *prefix)
1498{
1499        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1500        const char *curr_index;
1501        const char *index_name = NULL, *pack_name = NULL;
1502        const char *keep_name = NULL, *keep_msg = NULL;
1503        char *index_name_buf = NULL, *keep_name_buf = NULL;
1504        struct pack_idx_entry **idx_objects;
1505        struct pack_idx_option opts;
1506        unsigned char pack_sha1[20];
1507        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1508
1509        if (argc == 2 && !strcmp(argv[1], "-h"))
1510                usage(index_pack_usage);
1511
1512        check_replace_refs = 0;
1513
1514        reset_pack_idx_option(&opts);
1515        git_config(git_index_pack_config, &opts);
1516        if (prefix && chdir(prefix))
1517                die(_("Cannot come back to cwd"));
1518
1519        for (i = 1; i < argc; i++) {
1520                const char *arg = argv[i];
1521
1522                if (*arg == '-') {
1523                        if (!strcmp(arg, "--stdin")) {
1524                                from_stdin = 1;
1525                        } else if (!strcmp(arg, "--fix-thin")) {
1526                                fix_thin_pack = 1;
1527                        } else if (!strcmp(arg, "--strict")) {
1528                                strict = 1;
1529                                do_fsck_object = 1;
1530                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1531                                strict = 1;
1532                                check_self_contained_and_connected = 1;
1533                        } else if (!strcmp(arg, "--verify")) {
1534                                verify = 1;
1535                        } else if (!strcmp(arg, "--verify-stat")) {
1536                                verify = 1;
1537                                show_stat = 1;
1538                        } else if (!strcmp(arg, "--verify-stat-only")) {
1539                                verify = 1;
1540                                show_stat = 1;
1541                                stat_only = 1;
1542                        } else if (!strcmp(arg, "--keep")) {
1543                                keep_msg = "";
1544                        } else if (starts_with(arg, "--keep=")) {
1545                                keep_msg = arg + 7;
1546                        } else if (starts_with(arg, "--threads=")) {
1547                                char *end;
1548                                nr_threads = strtoul(arg+10, &end, 0);
1549                                if (!arg[10] || *end || nr_threads < 0)
1550                                        usage(index_pack_usage);
1551#ifdef NO_PTHREADS
1552                                if (nr_threads != 1)
1553                                        warning(_("no threads support, "
1554                                                  "ignoring %s"), arg);
1555                                nr_threads = 1;
1556#endif
1557                        } else if (starts_with(arg, "--pack_header=")) {
1558                                struct pack_header *hdr;
1559                                char *c;
1560
1561                                hdr = (struct pack_header *)input_buffer;
1562                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1563                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1564                                if (*c != ',')
1565                                        die(_("bad %s"), arg);
1566                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1567                                if (*c)
1568                                        die(_("bad %s"), arg);
1569                                input_len = sizeof(*hdr);
1570                        } else if (!strcmp(arg, "-v")) {
1571                                verbose = 1;
1572                        } else if (!strcmp(arg, "-o")) {
1573                                if (index_name || (i+1) >= argc)
1574                                        usage(index_pack_usage);
1575                                index_name = argv[++i];
1576                        } else if (starts_with(arg, "--index-version=")) {
1577                                char *c;
1578                                opts.version = strtoul(arg + 16, &c, 10);
1579                                if (opts.version > 2)
1580                                        die(_("bad %s"), arg);
1581                                if (*c == ',')
1582                                        opts.off32_limit = strtoul(c+1, &c, 0);
1583                                if (*c || opts.off32_limit & 0x80000000)
1584                                        die(_("bad %s"), arg);
1585                        } else
1586                                usage(index_pack_usage);
1587                        continue;
1588                }
1589
1590                if (pack_name)
1591                        usage(index_pack_usage);
1592                pack_name = arg;
1593        }
1594
1595        if (!pack_name && !from_stdin)
1596                usage(index_pack_usage);
1597        if (fix_thin_pack && !from_stdin)
1598                die(_("--fix-thin cannot be used without --stdin"));
1599        if (!index_name && pack_name) {
1600                int len = strlen(pack_name);
1601                if (!has_extension(pack_name, ".pack"))
1602                        die(_("packfile name '%s' does not end with '.pack'"),
1603                            pack_name);
1604                index_name_buf = xmalloc(len);
1605                memcpy(index_name_buf, pack_name, len - 5);
1606                strcpy(index_name_buf + len - 5, ".idx");
1607                index_name = index_name_buf;
1608        }
1609        if (keep_msg && !keep_name && pack_name) {
1610                int len = strlen(pack_name);
1611                if (!has_extension(pack_name, ".pack"))
1612                        die(_("packfile name '%s' does not end with '.pack'"),
1613                            pack_name);
1614                keep_name_buf = xmalloc(len);
1615                memcpy(keep_name_buf, pack_name, len - 5);
1616                strcpy(keep_name_buf + len - 5, ".keep");
1617                keep_name = keep_name_buf;
1618        }
1619        if (verify) {
1620                if (!index_name)
1621                        die(_("--verify with no packfile name given"));
1622                read_idx_option(&opts, index_name);
1623                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1624        }
1625        if (strict)
1626                opts.flags |= WRITE_IDX_STRICT;
1627
1628#ifndef NO_PTHREADS
1629        if (!nr_threads) {
1630                nr_threads = online_cpus();
1631                /* An experiment showed that more threads does not mean faster */
1632                if (nr_threads > 3)
1633                        nr_threads = 3;
1634        }
1635#endif
1636
1637        curr_pack = open_pack_file(pack_name);
1638        parse_pack_header();
1639        objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
1640        deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
1641        parse_pack_objects(pack_sha1);
1642        resolve_deltas();
1643        conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1644        free(deltas);
1645        if (strict)
1646                foreign_nr = check_objects();
1647
1648        if (show_stat)
1649                show_pack_info(stat_only);
1650
1651        idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
1652        for (i = 0; i < nr_objects; i++)
1653                idx_objects[i] = &objects[i].idx;
1654        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1655        free(idx_objects);
1656
1657        if (!verify)
1658                final(pack_name, curr_pack,
1659                      index_name, curr_index,
1660                      keep_name, keep_msg,
1661                      pack_sha1);
1662        else
1663                close(input_fd);
1664        free(objects);
1665        free(index_name_buf);
1666        free(keep_name_buf);
1667        if (pack_name == NULL)
1668                free((void *) curr_pack);
1669        if (index_name == NULL)
1670                free((void *) curr_index);
1671
1672        /*
1673         * Let the caller know this pack is not self contained
1674         */
1675        if (check_self_contained_and_connected && foreign_nr)
1676                return 1;
1677
1678        return 0;
1679}