builtin / index-pack.con commit receive-pack: crash when checking with non-exist HEAD (b112b14)
   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 <= 0)
 211                        die(_("did not receive expected object %s"),
 212                              sha1_to_hex(obj->sha1));
 213                if (type != obj->type)
 214                        die(_("object %s: expected type %s, found %s"),
 215                            sha1_to_hex(obj->sha1),
 216                            typename(obj->type), typename(type));
 217                obj->flags |= FLAG_CHECKED;
 218                return 1;
 219        }
 220
 221        return 0;
 222}
 223
 224static unsigned check_objects(void)
 225{
 226        unsigned i, max, foreign_nr = 0;
 227
 228        max = get_max_object_index();
 229        for (i = 0; i < max; i++)
 230                foreign_nr += check_object(get_indexed_object(i));
 231        return foreign_nr;
 232}
 233
 234
 235/* Discard current buffer used content. */
 236static void flush(void)
 237{
 238        if (input_offset) {
 239                if (output_fd >= 0)
 240                        write_or_die(output_fd, input_buffer, input_offset);
 241                git_SHA1_Update(&input_ctx, input_buffer, input_offset);
 242                memmove(input_buffer, input_buffer + input_offset, input_len);
 243                input_offset = 0;
 244        }
 245}
 246
 247/*
 248 * Make sure at least "min" bytes are available in the buffer, and
 249 * return the pointer to the buffer.
 250 */
 251static void *fill(int min)
 252{
 253        if (min <= input_len)
 254                return input_buffer + input_offset;
 255        if (min > sizeof(input_buffer))
 256                die(Q_("cannot fill %d byte",
 257                       "cannot fill %d bytes",
 258                       min),
 259                    min);
 260        flush();
 261        do {
 262                ssize_t ret = xread(input_fd, input_buffer + input_len,
 263                                sizeof(input_buffer) - input_len);
 264                if (ret <= 0) {
 265                        if (!ret)
 266                                die(_("early EOF"));
 267                        die_errno(_("read error on input"));
 268                }
 269                input_len += ret;
 270                if (from_stdin)
 271                        display_throughput(progress, consumed_bytes + input_len);
 272        } while (input_len < min);
 273        return input_buffer;
 274}
 275
 276static void use(int bytes)
 277{
 278        if (bytes > input_len)
 279                die(_("used more bytes than were available"));
 280        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 281        input_len -= bytes;
 282        input_offset += bytes;
 283
 284        /* make sure off_t is sufficiently large not to wrap */
 285        if (signed_add_overflows(consumed_bytes, bytes))
 286                die(_("pack too large for current definition of off_t"));
 287        consumed_bytes += bytes;
 288}
 289
 290static const char *open_pack_file(const char *pack_name)
 291{
 292        if (from_stdin) {
 293                input_fd = 0;
 294                if (!pack_name) {
 295                        static char tmp_file[PATH_MAX];
 296                        output_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
 297                                                "pack/tmp_pack_XXXXXX");
 298                        pack_name = xstrdup(tmp_file);
 299                } else
 300                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 301                if (output_fd < 0)
 302                        die_errno(_("unable to create '%s'"), pack_name);
 303                nothread_data.pack_fd = output_fd;
 304        } else {
 305                input_fd = open(pack_name, O_RDONLY);
 306                if (input_fd < 0)
 307                        die_errno(_("cannot open packfile '%s'"), pack_name);
 308                output_fd = -1;
 309                nothread_data.pack_fd = input_fd;
 310        }
 311        git_SHA1_Init(&input_ctx);
 312        return pack_name;
 313}
 314
 315static void parse_pack_header(void)
 316{
 317        struct pack_header *hdr = fill(sizeof(struct pack_header));
 318
 319        /* Header consistency check */
 320        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 321                die(_("pack signature mismatch"));
 322        if (!pack_version_ok(hdr->hdr_version))
 323                die(_("pack version %"PRIu32" unsupported"),
 324                        ntohl(hdr->hdr_version));
 325
 326        nr_objects = ntohl(hdr->hdr_entries);
 327        use(sizeof(struct pack_header));
 328}
 329
 330static NORETURN void bad_object(unsigned long offset, const char *format,
 331                       ...) __attribute__((format (printf, 2, 3)));
 332
 333static NORETURN void bad_object(unsigned long offset, const char *format, ...)
 334{
 335        va_list params;
 336        char buf[1024];
 337
 338        va_start(params, format);
 339        vsnprintf(buf, sizeof(buf), format, params);
 340        va_end(params);
 341        die(_("pack has bad object at offset %lu: %s"), offset, buf);
 342}
 343
 344static inline struct thread_local *get_thread_data(void)
 345{
 346#ifndef NO_PTHREADS
 347        if (threads_active)
 348                return pthread_getspecific(key);
 349        assert(!threads_active &&
 350               "This should only be reached when all threads are gone");
 351#endif
 352        return &nothread_data;
 353}
 354
 355#ifndef NO_PTHREADS
 356static void set_thread_data(struct thread_local *data)
 357{
 358        if (threads_active)
 359                pthread_setspecific(key, data);
 360}
 361#endif
 362
 363static struct base_data *alloc_base_data(void)
 364{
 365        struct base_data *base = xcalloc(1, sizeof(struct base_data));
 366        base->ref_last = -1;
 367        base->ofs_last = -1;
 368        return base;
 369}
 370
 371static void free_base_data(struct base_data *c)
 372{
 373        if (c->data) {
 374                free(c->data);
 375                c->data = NULL;
 376                get_thread_data()->base_cache_used -= c->size;
 377        }
 378}
 379
 380static void prune_base_data(struct base_data *retain)
 381{
 382        struct base_data *b;
 383        struct thread_local *data = get_thread_data();
 384        for (b = data->base_cache;
 385             data->base_cache_used > delta_base_cache_limit && b;
 386             b = b->child) {
 387                if (b->data && b != retain)
 388                        free_base_data(b);
 389        }
 390}
 391
 392static void link_base_data(struct base_data *base, struct base_data *c)
 393{
 394        if (base)
 395                base->child = c;
 396        else
 397                get_thread_data()->base_cache = c;
 398
 399        c->base = base;
 400        c->child = NULL;
 401        if (c->data)
 402                get_thread_data()->base_cache_used += c->size;
 403        prune_base_data(c);
 404}
 405
 406static void unlink_base_data(struct base_data *c)
 407{
 408        struct base_data *base = c->base;
 409        if (base)
 410                base->child = NULL;
 411        else
 412                get_thread_data()->base_cache = NULL;
 413        free_base_data(c);
 414}
 415
 416static int is_delta_type(enum object_type type)
 417{
 418        return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 419}
 420
 421static void *unpack_entry_data(unsigned long offset, unsigned long size,
 422                               enum object_type type, unsigned char *sha1)
 423{
 424        static char fixed_buf[8192];
 425        int status;
 426        git_zstream stream;
 427        void *buf;
 428        git_SHA_CTX c;
 429        char hdr[32];
 430        int hdrlen;
 431
 432        if (!is_delta_type(type)) {
 433                hdrlen = sprintf(hdr, "%s %lu", typename(type), size) + 1;
 434                git_SHA1_Init(&c);
 435                git_SHA1_Update(&c, hdr, hdrlen);
 436        } else
 437                sha1 = NULL;
 438        if (type == OBJ_BLOB && size > big_file_threshold)
 439                buf = fixed_buf;
 440        else
 441                buf = xmalloc(size);
 442
 443        memset(&stream, 0, sizeof(stream));
 444        git_inflate_init(&stream);
 445        stream.next_out = buf;
 446        stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 447
 448        do {
 449                unsigned char *last_out = stream.next_out;
 450                stream.next_in = fill(1);
 451                stream.avail_in = input_len;
 452                status = git_inflate(&stream, 0);
 453                use(input_len - stream.avail_in);
 454                if (sha1)
 455                        git_SHA1_Update(&c, last_out, stream.next_out - last_out);
 456                if (buf == fixed_buf) {
 457                        stream.next_out = buf;
 458                        stream.avail_out = sizeof(fixed_buf);
 459                }
 460        } while (status == Z_OK);
 461        if (stream.total_out != size || status != Z_STREAM_END)
 462                bad_object(offset, _("inflate returned %d"), status);
 463        git_inflate_end(&stream);
 464        if (sha1)
 465                git_SHA1_Final(sha1, &c);
 466        return buf == fixed_buf ? NULL : buf;
 467}
 468
 469static void *unpack_raw_entry(struct object_entry *obj,
 470                              union delta_base *delta_base,
 471                              unsigned char *sha1)
 472{
 473        unsigned char *p;
 474        unsigned long size, c;
 475        off_t base_offset;
 476        unsigned shift;
 477        void *data;
 478
 479        obj->idx.offset = consumed_bytes;
 480        input_crc32 = crc32(0, NULL, 0);
 481
 482        p = fill(1);
 483        c = *p;
 484        use(1);
 485        obj->type = (c >> 4) & 7;
 486        size = (c & 15);
 487        shift = 4;
 488        while (c & 0x80) {
 489                p = fill(1);
 490                c = *p;
 491                use(1);
 492                size += (c & 0x7f) << shift;
 493                shift += 7;
 494        }
 495        obj->size = size;
 496
 497        switch (obj->type) {
 498        case OBJ_REF_DELTA:
 499                hashcpy(delta_base->sha1, fill(20));
 500                use(20);
 501                break;
 502        case OBJ_OFS_DELTA:
 503                memset(delta_base, 0, sizeof(*delta_base));
 504                p = fill(1);
 505                c = *p;
 506                use(1);
 507                base_offset = c & 127;
 508                while (c & 128) {
 509                        base_offset += 1;
 510                        if (!base_offset || MSB(base_offset, 7))
 511                                bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 512                        p = fill(1);
 513                        c = *p;
 514                        use(1);
 515                        base_offset = (base_offset << 7) + (c & 127);
 516                }
 517                delta_base->offset = obj->idx.offset - base_offset;
 518                if (delta_base->offset <= 0 || delta_base->offset >= obj->idx.offset)
 519                        bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 520                break;
 521        case OBJ_COMMIT:
 522        case OBJ_TREE:
 523        case OBJ_BLOB:
 524        case OBJ_TAG:
 525                break;
 526        default:
 527                bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 528        }
 529        obj->hdr_size = consumed_bytes - obj->idx.offset;
 530
 531        data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, sha1);
 532        obj->idx.crc32 = input_crc32;
 533        return data;
 534}
 535
 536static void *unpack_data(struct object_entry *obj,
 537                         int (*consume)(const unsigned char *, unsigned long, void *),
 538                         void *cb_data)
 539{
 540        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 541        unsigned long len = obj[1].idx.offset - from;
 542        unsigned char *data, *inbuf;
 543        git_zstream stream;
 544        int status;
 545
 546        data = xmalloc(consume ? 64*1024 : obj->size);
 547        inbuf = xmalloc((len < 64*1024) ? len : 64*1024);
 548
 549        memset(&stream, 0, sizeof(stream));
 550        git_inflate_init(&stream);
 551        stream.next_out = data;
 552        stream.avail_out = consume ? 64*1024 : obj->size;
 553
 554        do {
 555                ssize_t n = (len < 64*1024) ? len : 64*1024;
 556                n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 557                if (n < 0)
 558                        die_errno(_("cannot pread pack file"));
 559                if (!n)
 560                        die(Q_("premature end of pack file, %lu byte missing",
 561                               "premature end of pack file, %lu bytes missing",
 562                               len),
 563                            len);
 564                from += n;
 565                len -= n;
 566                stream.next_in = inbuf;
 567                stream.avail_in = n;
 568                if (!consume)
 569                        status = git_inflate(&stream, 0);
 570                else {
 571                        do {
 572                                status = git_inflate(&stream, 0);
 573                                if (consume(data, stream.next_out - data, cb_data)) {
 574                                        free(inbuf);
 575                                        free(data);
 576                                        return NULL;
 577                                }
 578                                stream.next_out = data;
 579                                stream.avail_out = 64*1024;
 580                        } while (status == Z_OK && stream.avail_in);
 581                }
 582        } while (len && status == Z_OK && !stream.avail_in);
 583
 584        /* This has been inflated OK when first encountered, so... */
 585        if (status != Z_STREAM_END || stream.total_out != obj->size)
 586                die(_("serious inflate inconsistency"));
 587
 588        git_inflate_end(&stream);
 589        free(inbuf);
 590        if (consume) {
 591                free(data);
 592                data = NULL;
 593        }
 594        return data;
 595}
 596
 597static void *get_data_from_pack(struct object_entry *obj)
 598{
 599        return unpack_data(obj, NULL, NULL);
 600}
 601
 602static int compare_delta_bases(const union delta_base *base1,
 603                               const union delta_base *base2,
 604                               enum object_type type1,
 605                               enum object_type type2)
 606{
 607        int cmp = type1 - type2;
 608        if (cmp)
 609                return cmp;
 610        return memcmp(base1, base2, UNION_BASE_SZ);
 611}
 612
 613static int find_delta(const union delta_base *base, enum object_type type)
 614{
 615        int first = 0, last = nr_deltas;
 616
 617        while (first < last) {
 618                int next = (first + last) / 2;
 619                struct delta_entry *delta = &deltas[next];
 620                int cmp;
 621
 622                cmp = compare_delta_bases(base, &delta->base,
 623                                          type, objects[delta->obj_no].type);
 624                if (!cmp)
 625                        return next;
 626                if (cmp < 0) {
 627                        last = next;
 628                        continue;
 629                }
 630                first = next+1;
 631        }
 632        return -first-1;
 633}
 634
 635static void find_delta_children(const union delta_base *base,
 636                                int *first_index, int *last_index,
 637                                enum object_type type)
 638{
 639        int first = find_delta(base, type);
 640        int last = first;
 641        int end = nr_deltas - 1;
 642
 643        if (first < 0) {
 644                *first_index = 0;
 645                *last_index = -1;
 646                return;
 647        }
 648        while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
 649                --first;
 650        while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
 651                ++last;
 652        *first_index = first;
 653        *last_index = last;
 654}
 655
 656struct compare_data {
 657        struct object_entry *entry;
 658        struct git_istream *st;
 659        unsigned char *buf;
 660        unsigned long buf_size;
 661};
 662
 663static int compare_objects(const unsigned char *buf, unsigned long size,
 664                           void *cb_data)
 665{
 666        struct compare_data *data = cb_data;
 667
 668        if (data->buf_size < size) {
 669                free(data->buf);
 670                data->buf = xmalloc(size);
 671                data->buf_size = size;
 672        }
 673
 674        while (size) {
 675                ssize_t len = read_istream(data->st, data->buf, size);
 676                if (len == 0)
 677                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 678                            sha1_to_hex(data->entry->idx.sha1));
 679                if (len < 0)
 680                        die(_("unable to read %s"),
 681                            sha1_to_hex(data->entry->idx.sha1));
 682                if (memcmp(buf, data->buf, len))
 683                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 684                            sha1_to_hex(data->entry->idx.sha1));
 685                size -= len;
 686                buf += len;
 687        }
 688        return 0;
 689}
 690
 691static int check_collison(struct object_entry *entry)
 692{
 693        struct compare_data data;
 694        enum object_type type;
 695        unsigned long size;
 696
 697        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 698                return -1;
 699
 700        memset(&data, 0, sizeof(data));
 701        data.entry = entry;
 702        data.st = open_istream(entry->idx.sha1, &type, &size, NULL);
 703        if (!data.st)
 704                return -1;
 705        if (size != entry->size || type != entry->type)
 706                die(_("SHA1 COLLISION FOUND WITH %s !"),
 707                    sha1_to_hex(entry->idx.sha1));
 708        unpack_data(entry, compare_objects, &data);
 709        close_istream(data.st);
 710        free(data.buf);
 711        return 0;
 712}
 713
 714static void sha1_object(const void *data, struct object_entry *obj_entry,
 715                        unsigned long size, enum object_type type,
 716                        const unsigned char *sha1)
 717{
 718        void *new_data = NULL;
 719        int collision_test_needed;
 720
 721        assert(data || obj_entry);
 722
 723        read_lock();
 724        collision_test_needed = has_sha1_file(sha1);
 725        read_unlock();
 726
 727        if (collision_test_needed && !data) {
 728                read_lock();
 729                if (!check_collison(obj_entry))
 730                        collision_test_needed = 0;
 731                read_unlock();
 732        }
 733        if (collision_test_needed) {
 734                void *has_data;
 735                enum object_type has_type;
 736                unsigned long has_size;
 737                read_lock();
 738                has_type = sha1_object_info(sha1, &has_size);
 739                if (has_type != type || has_size != size)
 740                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 741                has_data = read_sha1_file(sha1, &has_type, &has_size);
 742                read_unlock();
 743                if (!data)
 744                        data = new_data = get_data_from_pack(obj_entry);
 745                if (!has_data)
 746                        die(_("cannot read existing object %s"), sha1_to_hex(sha1));
 747                if (size != has_size || type != has_type ||
 748                    memcmp(data, has_data, size) != 0)
 749                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 750                free(has_data);
 751        }
 752
 753        if (strict) {
 754                read_lock();
 755                if (type == OBJ_BLOB) {
 756                        struct blob *blob = lookup_blob(sha1);
 757                        if (blob)
 758                                blob->object.flags |= FLAG_CHECKED;
 759                        else
 760                                die(_("invalid blob object %s"), sha1_to_hex(sha1));
 761                } else {
 762                        struct object *obj;
 763                        int eaten;
 764                        void *buf = (void *) data;
 765
 766                        assert(data && "data can only be NULL for large _blobs_");
 767
 768                        /*
 769                         * we do not need to free the memory here, as the
 770                         * buf is deleted by the caller.
 771                         */
 772                        obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 773                        if (!obj)
 774                                die(_("invalid %s"), typename(type));
 775                        if (do_fsck_object &&
 776                            fsck_object(obj, 1, fsck_error_function))
 777                                die(_("Error in object"));
 778                        if (fsck_walk(obj, mark_link, NULL))
 779                                die(_("Not all child objects of %s are reachable"), sha1_to_hex(obj->sha1));
 780
 781                        if (obj->type == OBJ_TREE) {
 782                                struct tree *item = (struct tree *) obj;
 783                                item->buffer = NULL;
 784                                obj->parsed = 0;
 785                        }
 786                        if (obj->type == OBJ_COMMIT) {
 787                                struct commit *commit = (struct commit *) obj;
 788                                if (detach_commit_buffer(commit, NULL) != data)
 789                                        die("BUG: parse_object_buffer transmogrified our buffer");
 790                        }
 791                        obj->flags |= FLAG_CHECKED;
 792                }
 793                read_unlock();
 794        }
 795
 796        free(new_data);
 797}
 798
 799/*
 800 * This function is part of find_unresolved_deltas(). There are two
 801 * walkers going in the opposite ways.
 802 *
 803 * The first one in find_unresolved_deltas() traverses down from
 804 * parent node to children, deflating nodes along the way. However,
 805 * memory for deflated nodes is limited by delta_base_cache_limit, so
 806 * at some point parent node's deflated content may be freed.
 807 *
 808 * The second walker is this function, which goes from current node up
 809 * to top parent if necessary to deflate the node. In normal
 810 * situation, its parent node would be already deflated, so it just
 811 * needs to apply delta.
 812 *
 813 * In the worst case scenario, parent node is no longer deflated because
 814 * we're running out of delta_base_cache_limit; we need to re-deflate
 815 * parents, possibly up to the top base.
 816 *
 817 * All deflated objects here are subject to be freed if we exceed
 818 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 819 * just need to make sure the last node is not freed.
 820 */
 821static void *get_base_data(struct base_data *c)
 822{
 823        if (!c->data) {
 824                struct object_entry *obj = c->obj;
 825                struct base_data **delta = NULL;
 826                int delta_nr = 0, delta_alloc = 0;
 827
 828                while (is_delta_type(c->obj->type) && !c->data) {
 829                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 830                        delta[delta_nr++] = c;
 831                        c = c->base;
 832                }
 833                if (!delta_nr) {
 834                        c->data = get_data_from_pack(obj);
 835                        c->size = obj->size;
 836                        get_thread_data()->base_cache_used += c->size;
 837                        prune_base_data(c);
 838                }
 839                for (; delta_nr > 0; delta_nr--) {
 840                        void *base, *raw;
 841                        c = delta[delta_nr - 1];
 842                        obj = c->obj;
 843                        base = get_base_data(c->base);
 844                        raw = get_data_from_pack(obj);
 845                        c->data = patch_delta(
 846                                base, c->base->size,
 847                                raw, obj->size,
 848                                &c->size);
 849                        free(raw);
 850                        if (!c->data)
 851                                bad_object(obj->idx.offset, _("failed to apply delta"));
 852                        get_thread_data()->base_cache_used += c->size;
 853                        prune_base_data(c);
 854                }
 855                free(delta);
 856        }
 857        return c->data;
 858}
 859
 860static void resolve_delta(struct object_entry *delta_obj,
 861                          struct base_data *base, struct base_data *result)
 862{
 863        void *base_data, *delta_data;
 864
 865        delta_obj->real_type = base->obj->real_type;
 866        if (show_stat) {
 867                delta_obj->delta_depth = base->obj->delta_depth + 1;
 868                deepest_delta_lock();
 869                if (deepest_delta < delta_obj->delta_depth)
 870                        deepest_delta = delta_obj->delta_depth;
 871                deepest_delta_unlock();
 872        }
 873        delta_obj->base_object_no = base->obj - objects;
 874        delta_data = get_data_from_pack(delta_obj);
 875        base_data = get_base_data(base);
 876        result->obj = delta_obj;
 877        result->data = patch_delta(base_data, base->size,
 878                                   delta_data, delta_obj->size, &result->size);
 879        free(delta_data);
 880        if (!result->data)
 881                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 882        hash_sha1_file(result->data, result->size,
 883                       typename(delta_obj->real_type), delta_obj->idx.sha1);
 884        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 885                    delta_obj->idx.sha1);
 886        counter_lock();
 887        nr_resolved_deltas++;
 888        counter_unlock();
 889}
 890
 891static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 892                                                  struct base_data *prev_base)
 893{
 894        if (base->ref_last == -1 && base->ofs_last == -1) {
 895                union delta_base base_spec;
 896
 897                hashcpy(base_spec.sha1, base->obj->idx.sha1);
 898                find_delta_children(&base_spec,
 899                                    &base->ref_first, &base->ref_last, OBJ_REF_DELTA);
 900
 901                memset(&base_spec, 0, sizeof(base_spec));
 902                base_spec.offset = base->obj->idx.offset;
 903                find_delta_children(&base_spec,
 904                                    &base->ofs_first, &base->ofs_last, OBJ_OFS_DELTA);
 905
 906                if (base->ref_last == -1 && base->ofs_last == -1) {
 907                        free(base->data);
 908                        return NULL;
 909                }
 910
 911                link_base_data(prev_base, base);
 912        }
 913
 914        if (base->ref_first <= base->ref_last) {
 915                struct object_entry *child = objects + deltas[base->ref_first].obj_no;
 916                struct base_data *result = alloc_base_data();
 917
 918                assert(child->real_type == OBJ_REF_DELTA);
 919                resolve_delta(child, base, result);
 920                if (base->ref_first == base->ref_last && base->ofs_last == -1)
 921                        free_base_data(base);
 922
 923                base->ref_first++;
 924                return result;
 925        }
 926
 927        if (base->ofs_first <= base->ofs_last) {
 928                struct object_entry *child = objects + deltas[base->ofs_first].obj_no;
 929                struct base_data *result = alloc_base_data();
 930
 931                assert(child->real_type == OBJ_OFS_DELTA);
 932                resolve_delta(child, base, result);
 933                if (base->ofs_first == base->ofs_last)
 934                        free_base_data(base);
 935
 936                base->ofs_first++;
 937                return result;
 938        }
 939
 940        unlink_base_data(base);
 941        return NULL;
 942}
 943
 944static void find_unresolved_deltas(struct base_data *base)
 945{
 946        struct base_data *new_base, *prev_base = NULL;
 947        for (;;) {
 948                new_base = find_unresolved_deltas_1(base, prev_base);
 949
 950                if (new_base) {
 951                        prev_base = base;
 952                        base = new_base;
 953                } else {
 954                        free(base);
 955                        base = prev_base;
 956                        if (!base)
 957                                return;
 958                        prev_base = base->base;
 959                }
 960        }
 961}
 962
 963static int compare_delta_entry(const void *a, const void *b)
 964{
 965        const struct delta_entry *delta_a = a;
 966        const struct delta_entry *delta_b = b;
 967
 968        /* group by type (ref vs ofs) and then by value (sha-1 or offset) */
 969        return compare_delta_bases(&delta_a->base, &delta_b->base,
 970                                   objects[delta_a->obj_no].type,
 971                                   objects[delta_b->obj_no].type);
 972}
 973
 974static void resolve_base(struct object_entry *obj)
 975{
 976        struct base_data *base_obj = alloc_base_data();
 977        base_obj->obj = obj;
 978        base_obj->data = NULL;
 979        find_unresolved_deltas(base_obj);
 980}
 981
 982#ifndef NO_PTHREADS
 983static void *threaded_second_pass(void *data)
 984{
 985        set_thread_data(data);
 986        for (;;) {
 987                int i;
 988                counter_lock();
 989                display_progress(progress, nr_resolved_deltas);
 990                counter_unlock();
 991                work_lock();
 992                while (nr_dispatched < nr_objects &&
 993                       is_delta_type(objects[nr_dispatched].type))
 994                        nr_dispatched++;
 995                if (nr_dispatched >= nr_objects) {
 996                        work_unlock();
 997                        break;
 998                }
 999                i = nr_dispatched++;
1000                work_unlock();
1001
1002                resolve_base(&objects[i]);
1003        }
1004        return NULL;
1005}
1006#endif
1007
1008/*
1009 * First pass:
1010 * - find locations of all objects;
1011 * - calculate SHA1 of all non-delta objects;
1012 * - remember base (SHA1 or offset) for all deltas.
1013 */
1014static void parse_pack_objects(unsigned char *sha1)
1015{
1016        int i, nr_delays = 0;
1017        struct delta_entry *delta = deltas;
1018        struct stat st;
1019
1020        if (verbose)
1021                progress = start_progress(
1022                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1023                                nr_objects);
1024        for (i = 0; i < nr_objects; i++) {
1025                struct object_entry *obj = &objects[i];
1026                void *data = unpack_raw_entry(obj, &delta->base, obj->idx.sha1);
1027                obj->real_type = obj->type;
1028                if (is_delta_type(obj->type)) {
1029                        nr_deltas++;
1030                        delta->obj_no = i;
1031                        delta++;
1032                } else if (!data) {
1033                        /* large blobs, check later */
1034                        obj->real_type = OBJ_BAD;
1035                        nr_delays++;
1036                } else
1037                        sha1_object(data, NULL, obj->size, obj->type, obj->idx.sha1);
1038                free(data);
1039                display_progress(progress, i+1);
1040        }
1041        objects[i].idx.offset = consumed_bytes;
1042        stop_progress(&progress);
1043
1044        /* Check pack integrity */
1045        flush();
1046        git_SHA1_Final(sha1, &input_ctx);
1047        if (hashcmp(fill(20), sha1))
1048                die(_("pack is corrupted (SHA1 mismatch)"));
1049        use(20);
1050
1051        /* If input_fd is a file, we should have reached its end now. */
1052        if (fstat(input_fd, &st))
1053                die_errno(_("cannot fstat packfile"));
1054        if (S_ISREG(st.st_mode) &&
1055                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1056                die(_("pack has junk at the end"));
1057
1058        for (i = 0; i < nr_objects; i++) {
1059                struct object_entry *obj = &objects[i];
1060                if (obj->real_type != OBJ_BAD)
1061                        continue;
1062                obj->real_type = obj->type;
1063                sha1_object(NULL, obj, obj->size, obj->type, obj->idx.sha1);
1064                nr_delays--;
1065        }
1066        if (nr_delays)
1067                die(_("confusion beyond insanity in parse_pack_objects()"));
1068}
1069
1070/*
1071 * Second pass:
1072 * - for all non-delta objects, look if it is used as a base for
1073 *   deltas;
1074 * - if used as a base, uncompress the object and apply all deltas,
1075 *   recursively checking if the resulting object is used as a base
1076 *   for some more deltas.
1077 */
1078static void resolve_deltas(void)
1079{
1080        int i;
1081
1082        if (!nr_deltas)
1083                return;
1084
1085        /* Sort deltas by base SHA1/offset for fast searching */
1086        qsort(deltas, nr_deltas, sizeof(struct delta_entry),
1087              compare_delta_entry);
1088
1089        if (verbose)
1090                progress = start_progress(_("Resolving deltas"), nr_deltas);
1091
1092#ifndef NO_PTHREADS
1093        nr_dispatched = 0;
1094        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1095                init_thread();
1096                for (i = 0; i < nr_threads; i++) {
1097                        int ret = pthread_create(&thread_data[i].thread, NULL,
1098                                                 threaded_second_pass, thread_data + i);
1099                        if (ret)
1100                                die(_("unable to create thread: %s"),
1101                                    strerror(ret));
1102                }
1103                for (i = 0; i < nr_threads; i++)
1104                        pthread_join(thread_data[i].thread, NULL);
1105                cleanup_thread();
1106                return;
1107        }
1108#endif
1109
1110        for (i = 0; i < nr_objects; i++) {
1111                struct object_entry *obj = &objects[i];
1112
1113                if (is_delta_type(obj->type))
1114                        continue;
1115                resolve_base(obj);
1116                display_progress(progress, nr_resolved_deltas);
1117        }
1118}
1119
1120/*
1121 * Third pass:
1122 * - append objects to convert thin pack to full pack if required
1123 * - write the final 20-byte SHA-1
1124 */
1125static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved);
1126static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
1127{
1128        if (nr_deltas == nr_resolved_deltas) {
1129                stop_progress(&progress);
1130                /* Flush remaining pack final 20-byte SHA1. */
1131                flush();
1132                return;
1133        }
1134
1135        if (fix_thin_pack) {
1136                struct sha1file *f;
1137                unsigned char read_sha1[20], tail_sha1[20];
1138                struct strbuf msg = STRBUF_INIT;
1139                int nr_unresolved = nr_deltas - nr_resolved_deltas;
1140                int nr_objects_initial = nr_objects;
1141                if (nr_unresolved <= 0)
1142                        die(_("confusion beyond insanity"));
1143                objects = xrealloc(objects,
1144                                   (nr_objects + nr_unresolved + 1)
1145                                   * sizeof(*objects));
1146                memset(objects + nr_objects + 1, 0,
1147                       nr_unresolved * sizeof(*objects));
1148                f = sha1fd(output_fd, curr_pack);
1149                fix_unresolved_deltas(f, nr_unresolved);
1150                strbuf_addf(&msg, _("completed with %d local objects"),
1151                            nr_objects - nr_objects_initial);
1152                stop_progress_msg(&progress, msg.buf);
1153                strbuf_release(&msg);
1154                sha1close(f, tail_sha1, 0);
1155                hashcpy(read_sha1, pack_sha1);
1156                fixup_pack_header_footer(output_fd, pack_sha1,
1157                                         curr_pack, nr_objects,
1158                                         read_sha1, consumed_bytes-20);
1159                if (hashcmp(read_sha1, tail_sha1) != 0)
1160                        die(_("Unexpected tail checksum for %s "
1161                              "(disk corruption?)"), curr_pack);
1162        }
1163        if (nr_deltas != nr_resolved_deltas)
1164                die(Q_("pack has %d unresolved delta",
1165                       "pack has %d unresolved deltas",
1166                       nr_deltas - nr_resolved_deltas),
1167                    nr_deltas - nr_resolved_deltas);
1168}
1169
1170static int write_compressed(struct sha1file *f, void *in, unsigned int size)
1171{
1172        git_zstream stream;
1173        int status;
1174        unsigned char outbuf[4096];
1175
1176        memset(&stream, 0, sizeof(stream));
1177        git_deflate_init(&stream, zlib_compression_level);
1178        stream.next_in = in;
1179        stream.avail_in = size;
1180
1181        do {
1182                stream.next_out = outbuf;
1183                stream.avail_out = sizeof(outbuf);
1184                status = git_deflate(&stream, Z_FINISH);
1185                sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
1186        } while (status == Z_OK);
1187
1188        if (status != Z_STREAM_END)
1189                die(_("unable to deflate appended object (%d)"), status);
1190        size = stream.total_out;
1191        git_deflate_end(&stream);
1192        return size;
1193}
1194
1195static struct object_entry *append_obj_to_pack(struct sha1file *f,
1196                               const unsigned char *sha1, void *buf,
1197                               unsigned long size, enum object_type type)
1198{
1199        struct object_entry *obj = &objects[nr_objects++];
1200        unsigned char header[10];
1201        unsigned long s = size;
1202        int n = 0;
1203        unsigned char c = (type << 4) | (s & 15);
1204        s >>= 4;
1205        while (s) {
1206                header[n++] = c | 0x80;
1207                c = s & 0x7f;
1208                s >>= 7;
1209        }
1210        header[n++] = c;
1211        crc32_begin(f);
1212        sha1write(f, header, n);
1213        obj[0].size = size;
1214        obj[0].hdr_size = n;
1215        obj[0].type = type;
1216        obj[0].real_type = type;
1217        obj[1].idx.offset = obj[0].idx.offset + n;
1218        obj[1].idx.offset += write_compressed(f, buf, size);
1219        obj[0].idx.crc32 = crc32_end(f);
1220        sha1flush(f);
1221        hashcpy(obj->idx.sha1, sha1);
1222        return obj;
1223}
1224
1225static int delta_pos_compare(const void *_a, const void *_b)
1226{
1227        struct delta_entry *a = *(struct delta_entry **)_a;
1228        struct delta_entry *b = *(struct delta_entry **)_b;
1229        return a->obj_no - b->obj_no;
1230}
1231
1232static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
1233{
1234        struct delta_entry **sorted_by_pos;
1235        int i, n = 0;
1236
1237        /*
1238         * Since many unresolved deltas may well be themselves base objects
1239         * for more unresolved deltas, we really want to include the
1240         * smallest number of base objects that would cover as much delta
1241         * as possible by picking the
1242         * trunc deltas first, allowing for other deltas to resolve without
1243         * additional base objects.  Since most base objects are to be found
1244         * before deltas depending on them, a good heuristic is to start
1245         * resolving deltas in the same order as their position in the pack.
1246         */
1247        sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
1248        for (i = 0; i < nr_deltas; i++) {
1249                if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
1250                        continue;
1251                sorted_by_pos[n++] = &deltas[i];
1252        }
1253        qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
1254
1255        for (i = 0; i < n; i++) {
1256                struct delta_entry *d = sorted_by_pos[i];
1257                enum object_type type;
1258                struct base_data *base_obj = alloc_base_data();
1259
1260                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1261                        continue;
1262                base_obj->data = read_sha1_file(d->base.sha1, &type, &base_obj->size);
1263                if (!base_obj->data)
1264                        continue;
1265
1266                if (check_sha1_signature(d->base.sha1, base_obj->data,
1267                                base_obj->size, typename(type)))
1268                        die(_("local object %s is corrupt"), sha1_to_hex(d->base.sha1));
1269                base_obj->obj = append_obj_to_pack(f, d->base.sha1,
1270                                        base_obj->data, base_obj->size, type);
1271                find_unresolved_deltas(base_obj);
1272                display_progress(progress, nr_resolved_deltas);
1273        }
1274        free(sorted_by_pos);
1275}
1276
1277static void final(const char *final_pack_name, const char *curr_pack_name,
1278                  const char *final_index_name, const char *curr_index_name,
1279                  const char *keep_name, const char *keep_msg,
1280                  unsigned char *sha1)
1281{
1282        const char *report = "pack";
1283        char name[PATH_MAX];
1284        int err;
1285
1286        if (!from_stdin) {
1287                close(input_fd);
1288        } else {
1289                fsync_or_die(output_fd, curr_pack_name);
1290                err = close(output_fd);
1291                if (err)
1292                        die_errno(_("error while closing pack file"));
1293        }
1294
1295        if (keep_msg) {
1296                int keep_fd, keep_msg_len = strlen(keep_msg);
1297
1298                if (!keep_name)
1299                        keep_fd = odb_pack_keep(name, sizeof(name), sha1);
1300                else
1301                        keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
1302
1303                if (keep_fd < 0) {
1304                        if (errno != EEXIST)
1305                                die_errno(_("cannot write keep file '%s'"),
1306                                          keep_name ? keep_name : name);
1307                } else {
1308                        if (keep_msg_len > 0) {
1309                                write_or_die(keep_fd, keep_msg, keep_msg_len);
1310                                write_or_die(keep_fd, "\n", 1);
1311                        }
1312                        if (close(keep_fd) != 0)
1313                                die_errno(_("cannot close written keep file '%s'"),
1314                                          keep_name ? keep_name : name);
1315                        report = "keep";
1316                }
1317        }
1318
1319        if (final_pack_name != curr_pack_name) {
1320                if (!final_pack_name) {
1321                        snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
1322                                 get_object_directory(), sha1_to_hex(sha1));
1323                        final_pack_name = name;
1324                }
1325                if (move_temp_to_file(curr_pack_name, final_pack_name))
1326                        die(_("cannot store pack file"));
1327        } else if (from_stdin)
1328                chmod(final_pack_name, 0444);
1329
1330        if (final_index_name != curr_index_name) {
1331                if (!final_index_name) {
1332                        snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
1333                                 get_object_directory(), sha1_to_hex(sha1));
1334                        final_index_name = name;
1335                }
1336                if (move_temp_to_file(curr_index_name, final_index_name))
1337                        die(_("cannot store index file"));
1338        } else
1339                chmod(final_index_name, 0444);
1340
1341        if (!from_stdin) {
1342                printf("%s\n", sha1_to_hex(sha1));
1343        } else {
1344                char buf[48];
1345                int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
1346                                   report, sha1_to_hex(sha1));
1347                write_or_die(1, buf, len);
1348
1349                /*
1350                 * Let's just mimic git-unpack-objects here and write
1351                 * the last part of the input buffer to stdout.
1352                 */
1353                while (input_len) {
1354                        err = xwrite(1, input_buffer + input_offset, input_len);
1355                        if (err <= 0)
1356                                break;
1357                        input_len -= err;
1358                        input_offset += err;
1359                }
1360        }
1361}
1362
1363static int git_index_pack_config(const char *k, const char *v, void *cb)
1364{
1365        struct pack_idx_option *opts = cb;
1366
1367        if (!strcmp(k, "pack.indexversion")) {
1368                opts->version = git_config_int(k, v);
1369                if (opts->version > 2)
1370                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1371                return 0;
1372        }
1373        if (!strcmp(k, "pack.threads")) {
1374                nr_threads = git_config_int(k, v);
1375                if (nr_threads < 0)
1376                        die(_("invalid number of threads specified (%d)"),
1377                            nr_threads);
1378#ifdef NO_PTHREADS
1379                if (nr_threads != 1)
1380                        warning(_("no threads support, ignoring %s"), k);
1381                nr_threads = 1;
1382#endif
1383                return 0;
1384        }
1385        return git_default_config(k, v, cb);
1386}
1387
1388static int cmp_uint32(const void *a_, const void *b_)
1389{
1390        uint32_t a = *((uint32_t *)a_);
1391        uint32_t b = *((uint32_t *)b_);
1392
1393        return (a < b) ? -1 : (a != b);
1394}
1395
1396static void read_v2_anomalous_offsets(struct packed_git *p,
1397                                      struct pack_idx_option *opts)
1398{
1399        const uint32_t *idx1, *idx2;
1400        uint32_t i;
1401
1402        /* The address of the 4-byte offset table */
1403        idx1 = (((const uint32_t *)p->index_data)
1404                + 2 /* 8-byte header */
1405                + 256 /* fan out */
1406                + 5 * p->num_objects /* 20-byte SHA-1 table */
1407                + p->num_objects /* CRC32 table */
1408                );
1409
1410        /* The address of the 8-byte offset table */
1411        idx2 = idx1 + p->num_objects;
1412
1413        for (i = 0; i < p->num_objects; i++) {
1414                uint32_t off = ntohl(idx1[i]);
1415                if (!(off & 0x80000000))
1416                        continue;
1417                off = off & 0x7fffffff;
1418                if (idx2[off * 2])
1419                        continue;
1420                /*
1421                 * The real offset is ntohl(idx2[off * 2]) in high 4
1422                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1423                 * octets.  But idx2[off * 2] is Zero!!!
1424                 */
1425                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1426                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1427        }
1428
1429        if (1 < opts->anomaly_nr)
1430                qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
1431}
1432
1433static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1434{
1435        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1436
1437        if (!p)
1438                die(_("Cannot open existing pack file '%s'"), pack_name);
1439        if (open_pack_index(p))
1440                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1441
1442        /* Read the attributes from the existing idx file */
1443        opts->version = p->index_version;
1444
1445        if (opts->version == 2)
1446                read_v2_anomalous_offsets(p, opts);
1447
1448        /*
1449         * Get rid of the idx file as we do not need it anymore.
1450         * NEEDSWORK: extract this bit from free_pack_by_name() in
1451         * sha1_file.c, perhaps?  It shouldn't matter very much as we
1452         * know we haven't installed this pack (hence we never have
1453         * read anything from it).
1454         */
1455        close_pack_index(p);
1456        free(p);
1457}
1458
1459static void show_pack_info(int stat_only)
1460{
1461        int i, baseobjects = nr_objects - nr_deltas;
1462        unsigned long *chain_histogram = NULL;
1463
1464        if (deepest_delta)
1465                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1466
1467        for (i = 0; i < nr_objects; i++) {
1468                struct object_entry *obj = &objects[i];
1469
1470                if (is_delta_type(obj->type))
1471                        chain_histogram[obj->delta_depth - 1]++;
1472                if (stat_only)
1473                        continue;
1474                printf("%s %-6s %lu %lu %"PRIuMAX,
1475                       sha1_to_hex(obj->idx.sha1),
1476                       typename(obj->real_type), obj->size,
1477                       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1478                       (uintmax_t)obj->idx.offset);
1479                if (is_delta_type(obj->type)) {
1480                        struct object_entry *bobj = &objects[obj->base_object_no];
1481                        printf(" %u %s", obj->delta_depth, sha1_to_hex(bobj->idx.sha1));
1482                }
1483                putchar('\n');
1484        }
1485
1486        if (baseobjects)
1487                printf_ln(Q_("non delta: %d object",
1488                             "non delta: %d objects",
1489                             baseobjects),
1490                          baseobjects);
1491        for (i = 0; i < deepest_delta; i++) {
1492                if (!chain_histogram[i])
1493                        continue;
1494                printf_ln(Q_("chain length = %d: %lu object",
1495                             "chain length = %d: %lu objects",
1496                             chain_histogram[i]),
1497                          i + 1,
1498                          chain_histogram[i]);
1499        }
1500}
1501
1502int cmd_index_pack(int argc, const char **argv, const char *prefix)
1503{
1504        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1505        const char *curr_index;
1506        const char *index_name = NULL, *pack_name = NULL;
1507        const char *keep_name = NULL, *keep_msg = NULL;
1508        char *index_name_buf = NULL, *keep_name_buf = NULL;
1509        struct pack_idx_entry **idx_objects;
1510        struct pack_idx_option opts;
1511        unsigned char pack_sha1[20];
1512        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1513
1514        if (argc == 2 && !strcmp(argv[1], "-h"))
1515                usage(index_pack_usage);
1516
1517        check_replace_refs = 0;
1518
1519        reset_pack_idx_option(&opts);
1520        git_config(git_index_pack_config, &opts);
1521        if (prefix && chdir(prefix))
1522                die(_("Cannot come back to cwd"));
1523
1524        for (i = 1; i < argc; i++) {
1525                const char *arg = argv[i];
1526
1527                if (*arg == '-') {
1528                        if (!strcmp(arg, "--stdin")) {
1529                                from_stdin = 1;
1530                        } else if (!strcmp(arg, "--fix-thin")) {
1531                                fix_thin_pack = 1;
1532                        } else if (!strcmp(arg, "--strict")) {
1533                                strict = 1;
1534                                do_fsck_object = 1;
1535                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1536                                strict = 1;
1537                                check_self_contained_and_connected = 1;
1538                        } else if (!strcmp(arg, "--verify")) {
1539                                verify = 1;
1540                        } else if (!strcmp(arg, "--verify-stat")) {
1541                                verify = 1;
1542                                show_stat = 1;
1543                        } else if (!strcmp(arg, "--verify-stat-only")) {
1544                                verify = 1;
1545                                show_stat = 1;
1546                                stat_only = 1;
1547                        } else if (!strcmp(arg, "--keep")) {
1548                                keep_msg = "";
1549                        } else if (starts_with(arg, "--keep=")) {
1550                                keep_msg = arg + 7;
1551                        } else if (starts_with(arg, "--threads=")) {
1552                                char *end;
1553                                nr_threads = strtoul(arg+10, &end, 0);
1554                                if (!arg[10] || *end || nr_threads < 0)
1555                                        usage(index_pack_usage);
1556#ifdef NO_PTHREADS
1557                                if (nr_threads != 1)
1558                                        warning(_("no threads support, "
1559                                                  "ignoring %s"), arg);
1560                                nr_threads = 1;
1561#endif
1562                        } else if (starts_with(arg, "--pack_header=")) {
1563                                struct pack_header *hdr;
1564                                char *c;
1565
1566                                hdr = (struct pack_header *)input_buffer;
1567                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1568                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1569                                if (*c != ',')
1570                                        die(_("bad %s"), arg);
1571                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1572                                if (*c)
1573                                        die(_("bad %s"), arg);
1574                                input_len = sizeof(*hdr);
1575                        } else if (!strcmp(arg, "-v")) {
1576                                verbose = 1;
1577                        } else if (!strcmp(arg, "-o")) {
1578                                if (index_name || (i+1) >= argc)
1579                                        usage(index_pack_usage);
1580                                index_name = argv[++i];
1581                        } else if (starts_with(arg, "--index-version=")) {
1582                                char *c;
1583                                opts.version = strtoul(arg + 16, &c, 10);
1584                                if (opts.version > 2)
1585                                        die(_("bad %s"), arg);
1586                                if (*c == ',')
1587                                        opts.off32_limit = strtoul(c+1, &c, 0);
1588                                if (*c || opts.off32_limit & 0x80000000)
1589                                        die(_("bad %s"), arg);
1590                        } else
1591                                usage(index_pack_usage);
1592                        continue;
1593                }
1594
1595                if (pack_name)
1596                        usage(index_pack_usage);
1597                pack_name = arg;
1598        }
1599
1600        if (!pack_name && !from_stdin)
1601                usage(index_pack_usage);
1602        if (fix_thin_pack && !from_stdin)
1603                die(_("--fix-thin cannot be used without --stdin"));
1604        if (!index_name && pack_name) {
1605                int len = strlen(pack_name);
1606                if (!has_extension(pack_name, ".pack"))
1607                        die(_("packfile name '%s' does not end with '.pack'"),
1608                            pack_name);
1609                index_name_buf = xmalloc(len);
1610                memcpy(index_name_buf, pack_name, len - 5);
1611                strcpy(index_name_buf + len - 5, ".idx");
1612                index_name = index_name_buf;
1613        }
1614        if (keep_msg && !keep_name && pack_name) {
1615                int len = strlen(pack_name);
1616                if (!has_extension(pack_name, ".pack"))
1617                        die(_("packfile name '%s' does not end with '.pack'"),
1618                            pack_name);
1619                keep_name_buf = xmalloc(len);
1620                memcpy(keep_name_buf, pack_name, len - 5);
1621                strcpy(keep_name_buf + len - 5, ".keep");
1622                keep_name = keep_name_buf;
1623        }
1624        if (verify) {
1625                if (!index_name)
1626                        die(_("--verify with no packfile name given"));
1627                read_idx_option(&opts, index_name);
1628                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1629        }
1630        if (strict)
1631                opts.flags |= WRITE_IDX_STRICT;
1632
1633#ifndef NO_PTHREADS
1634        if (!nr_threads) {
1635                nr_threads = online_cpus();
1636                /* An experiment showed that more threads does not mean faster */
1637                if (nr_threads > 3)
1638                        nr_threads = 3;
1639        }
1640#endif
1641
1642        curr_pack = open_pack_file(pack_name);
1643        parse_pack_header();
1644        objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
1645        deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
1646        parse_pack_objects(pack_sha1);
1647        resolve_deltas();
1648        conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1649        free(deltas);
1650        if (strict)
1651                foreign_nr = check_objects();
1652
1653        if (show_stat)
1654                show_pack_info(stat_only);
1655
1656        idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
1657        for (i = 0; i < nr_objects; i++)
1658                idx_objects[i] = &objects[i].idx;
1659        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1660        free(idx_objects);
1661
1662        if (!verify)
1663                final(pack_name, curr_pack,
1664                      index_name, curr_index,
1665                      keep_name, keep_msg,
1666                      pack_sha1);
1667        else
1668                close(input_fd);
1669        free(objects);
1670        free(index_name_buf);
1671        free(keep_name_buf);
1672        if (pack_name == NULL)
1673                free((void *) curr_pack);
1674        if (index_name == NULL)
1675                free((void *) curr_index);
1676
1677        /*
1678         * Let the caller know this pack is not self contained
1679         */
1680        if (check_self_contained_and_connected && foreign_nr)
1681                return 1;
1682
1683        return 0;
1684}