42551ce4ff65c170fffb88c5e9bb639bfc83fe91
   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
  43#if !defined(NO_PTHREADS) && defined(NO_THREAD_SAFE_PREAD)
  44/* pread() emulation is not thread-safe. Disable threading. */
  45#define NO_PTHREADS
  46#endif
  47
  48struct thread_local {
  49#ifndef NO_PTHREADS
  50        pthread_t thread;
  51#endif
  52        struct base_data *base_cache;
  53        size_t base_cache_used;
  54};
  55
  56/*
  57 * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
  58 * to memcmp() only the first 20 bytes.
  59 */
  60#define UNION_BASE_SZ   20
  61
  62#define FLAG_LINK (1u<<20)
  63#define FLAG_CHECKED (1u<<21)
  64
  65struct delta_entry {
  66        union delta_base base;
  67        int obj_no;
  68};
  69
  70static struct object_entry *objects;
  71static struct delta_entry *deltas;
  72static struct thread_local nothread_data;
  73static int nr_objects;
  74static int nr_deltas;
  75static int nr_resolved_deltas;
  76static int nr_threads;
  77
  78static int from_stdin;
  79static int strict;
  80static int do_fsck_object;
  81static int verbose;
  82static int show_stat;
  83static int check_self_contained_and_connected;
  84
  85static struct progress *progress;
  86
  87/* We always read in 4kB chunks. */
  88static unsigned char input_buffer[4096];
  89static unsigned int input_offset, input_len;
  90static off_t consumed_bytes;
  91static unsigned deepest_delta;
  92static git_SHA_CTX input_ctx;
  93static uint32_t input_crc32;
  94static int input_fd, output_fd, pack_fd;
  95
  96#ifndef NO_PTHREADS
  97
  98static struct thread_local *thread_data;
  99static int nr_dispatched;
 100static int threads_active;
 101
 102static pthread_mutex_t read_mutex;
 103#define read_lock()             lock_mutex(&read_mutex)
 104#define read_unlock()           unlock_mutex(&read_mutex)
 105
 106static pthread_mutex_t counter_mutex;
 107#define counter_lock()          lock_mutex(&counter_mutex)
 108#define counter_unlock()        unlock_mutex(&counter_mutex)
 109
 110static pthread_mutex_t work_mutex;
 111#define work_lock()             lock_mutex(&work_mutex)
 112#define work_unlock()           unlock_mutex(&work_mutex)
 113
 114static pthread_mutex_t deepest_delta_mutex;
 115#define deepest_delta_lock()    lock_mutex(&deepest_delta_mutex)
 116#define deepest_delta_unlock()  unlock_mutex(&deepest_delta_mutex)
 117
 118static pthread_key_t key;
 119
 120static inline void lock_mutex(pthread_mutex_t *mutex)
 121{
 122        if (threads_active)
 123                pthread_mutex_lock(mutex);
 124}
 125
 126static inline void unlock_mutex(pthread_mutex_t *mutex)
 127{
 128        if (threads_active)
 129                pthread_mutex_unlock(mutex);
 130}
 131
 132/*
 133 * Mutex and conditional variable can't be statically-initialized on Windows.
 134 */
 135static void init_thread(void)
 136{
 137        init_recursive_mutex(&read_mutex);
 138        pthread_mutex_init(&counter_mutex, NULL);
 139        pthread_mutex_init(&work_mutex, NULL);
 140        if (show_stat)
 141                pthread_mutex_init(&deepest_delta_mutex, NULL);
 142        pthread_key_create(&key, NULL);
 143        thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 144        threads_active = 1;
 145}
 146
 147static void cleanup_thread(void)
 148{
 149        if (!threads_active)
 150                return;
 151        threads_active = 0;
 152        pthread_mutex_destroy(&read_mutex);
 153        pthread_mutex_destroy(&counter_mutex);
 154        pthread_mutex_destroy(&work_mutex);
 155        if (show_stat)
 156                pthread_mutex_destroy(&deepest_delta_mutex);
 157        pthread_key_delete(key);
 158        free(thread_data);
 159}
 160
 161#else
 162
 163#define read_lock()
 164#define read_unlock()
 165
 166#define counter_lock()
 167#define counter_unlock()
 168
 169#define work_lock()
 170#define work_unlock()
 171
 172#define deepest_delta_lock()
 173#define deepest_delta_unlock()
 174
 175#endif
 176
 177
 178static int mark_link(struct object *obj, int type, void *data)
 179{
 180        if (!obj)
 181                return -1;
 182
 183        if (type != OBJ_ANY && obj->type != type)
 184                die(_("object type mismatch at %s"), sha1_to_hex(obj->sha1));
 185
 186        obj->flags |= FLAG_LINK;
 187        return 0;
 188}
 189
 190/* The content of each linked object must have been checked
 191   or it must be already present in the object database */
 192static unsigned check_object(struct object *obj)
 193{
 194        if (!obj)
 195                return 0;
 196
 197        if (!(obj->flags & FLAG_LINK))
 198                return 0;
 199
 200        if (!(obj->flags & FLAG_CHECKED)) {
 201                unsigned long size;
 202                int type = sha1_object_info(obj->sha1, &size);
 203                if (type != obj->type || type <= 0)
 204                        die(_("object of unexpected type"));
 205                obj->flags |= FLAG_CHECKED;
 206                return 1;
 207        }
 208
 209        return 0;
 210}
 211
 212static unsigned check_objects(void)
 213{
 214        unsigned i, max, foreign_nr = 0;
 215
 216        max = get_max_object_index();
 217        for (i = 0; i < max; i++)
 218                foreign_nr += check_object(get_indexed_object(i));
 219        return foreign_nr;
 220}
 221
 222
 223/* Discard current buffer used content. */
 224static void flush(void)
 225{
 226        if (input_offset) {
 227                if (output_fd >= 0)
 228                        write_or_die(output_fd, input_buffer, input_offset);
 229                git_SHA1_Update(&input_ctx, input_buffer, input_offset);
 230                memmove(input_buffer, input_buffer + input_offset, input_len);
 231                input_offset = 0;
 232        }
 233}
 234
 235/*
 236 * Make sure at least "min" bytes are available in the buffer, and
 237 * return the pointer to the buffer.
 238 */
 239static void *fill(int min)
 240{
 241        if (min <= input_len)
 242                return input_buffer + input_offset;
 243        if (min > sizeof(input_buffer))
 244                die(Q_("cannot fill %d byte",
 245                       "cannot fill %d bytes",
 246                       min),
 247                    min);
 248        flush();
 249        do {
 250                ssize_t ret = xread(input_fd, input_buffer + input_len,
 251                                sizeof(input_buffer) - input_len);
 252                if (ret <= 0) {
 253                        if (!ret)
 254                                die(_("early EOF"));
 255                        die_errno(_("read error on input"));
 256                }
 257                input_len += ret;
 258                if (from_stdin)
 259                        display_throughput(progress, consumed_bytes + input_len);
 260        } while (input_len < min);
 261        return input_buffer;
 262}
 263
 264static void use(int bytes)
 265{
 266        if (bytes > input_len)
 267                die(_("used more bytes than were available"));
 268        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 269        input_len -= bytes;
 270        input_offset += bytes;
 271
 272        /* make sure off_t is sufficiently large not to wrap */
 273        if (signed_add_overflows(consumed_bytes, bytes))
 274                die(_("pack too large for current definition of off_t"));
 275        consumed_bytes += bytes;
 276}
 277
 278static const char *open_pack_file(const char *pack_name)
 279{
 280        if (from_stdin) {
 281                input_fd = 0;
 282                if (!pack_name) {
 283                        static char tmp_file[PATH_MAX];
 284                        output_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
 285                                                "pack/tmp_pack_XXXXXX");
 286                        pack_name = xstrdup(tmp_file);
 287                } else
 288                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 289                if (output_fd < 0)
 290                        die_errno(_("unable to create '%s'"), pack_name);
 291                pack_fd = output_fd;
 292        } else {
 293                input_fd = open(pack_name, O_RDONLY);
 294                if (input_fd < 0)
 295                        die_errno(_("cannot open packfile '%s'"), pack_name);
 296                output_fd = -1;
 297                pack_fd = input_fd;
 298        }
 299        git_SHA1_Init(&input_ctx);
 300        return pack_name;
 301}
 302
 303static void parse_pack_header(void)
 304{
 305        struct pack_header *hdr = fill(sizeof(struct pack_header));
 306
 307        /* Header consistency check */
 308        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 309                die(_("pack signature mismatch"));
 310        if (!pack_version_ok(hdr->hdr_version))
 311                die(_("pack version %"PRIu32" unsupported"),
 312                        ntohl(hdr->hdr_version));
 313
 314        nr_objects = ntohl(hdr->hdr_entries);
 315        use(sizeof(struct pack_header));
 316}
 317
 318static NORETURN void bad_object(unsigned long offset, const char *format,
 319                       ...) __attribute__((format (printf, 2, 3)));
 320
 321static NORETURN void bad_object(unsigned long offset, const char *format, ...)
 322{
 323        va_list params;
 324        char buf[1024];
 325
 326        va_start(params, format);
 327        vsnprintf(buf, sizeof(buf), format, params);
 328        va_end(params);
 329        die(_("pack has bad object at offset %lu: %s"), offset, buf);
 330}
 331
 332static inline struct thread_local *get_thread_data(void)
 333{
 334#ifndef NO_PTHREADS
 335        if (threads_active)
 336                return pthread_getspecific(key);
 337        assert(!threads_active &&
 338               "This should only be reached when all threads are gone");
 339#endif
 340        return &nothread_data;
 341}
 342
 343#ifndef NO_PTHREADS
 344static void set_thread_data(struct thread_local *data)
 345{
 346        if (threads_active)
 347                pthread_setspecific(key, data);
 348}
 349#endif
 350
 351static struct base_data *alloc_base_data(void)
 352{
 353        struct base_data *base = xmalloc(sizeof(struct base_data));
 354        memset(base, 0, sizeof(*base));
 355        base->ref_last = -1;
 356        base->ofs_last = -1;
 357        return base;
 358}
 359
 360static void free_base_data(struct base_data *c)
 361{
 362        if (c->data) {
 363                free(c->data);
 364                c->data = NULL;
 365                get_thread_data()->base_cache_used -= c->size;
 366        }
 367}
 368
 369static void prune_base_data(struct base_data *retain)
 370{
 371        struct base_data *b;
 372        struct thread_local *data = get_thread_data();
 373        for (b = data->base_cache;
 374             data->base_cache_used > delta_base_cache_limit && b;
 375             b = b->child) {
 376                if (b->data && b != retain)
 377                        free_base_data(b);
 378        }
 379}
 380
 381static void link_base_data(struct base_data *base, struct base_data *c)
 382{
 383        if (base)
 384                base->child = c;
 385        else
 386                get_thread_data()->base_cache = c;
 387
 388        c->base = base;
 389        c->child = NULL;
 390        if (c->data)
 391                get_thread_data()->base_cache_used += c->size;
 392        prune_base_data(c);
 393}
 394
 395static void unlink_base_data(struct base_data *c)
 396{
 397        struct base_data *base = c->base;
 398        if (base)
 399                base->child = NULL;
 400        else
 401                get_thread_data()->base_cache = NULL;
 402        free_base_data(c);
 403}
 404
 405static int is_delta_type(enum object_type type)
 406{
 407        return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 408}
 409
 410static void *unpack_entry_data(unsigned long offset, unsigned long size,
 411                               enum object_type type, unsigned char *sha1)
 412{
 413        static char fixed_buf[8192];
 414        int status;
 415        git_zstream stream;
 416        void *buf;
 417        git_SHA_CTX c;
 418        char hdr[32];
 419        int hdrlen;
 420
 421        if (!is_delta_type(type)) {
 422                hdrlen = sprintf(hdr, "%s %lu", typename(type), size) + 1;
 423                git_SHA1_Init(&c);
 424                git_SHA1_Update(&c, hdr, hdrlen);
 425        } else
 426                sha1 = NULL;
 427        if (type == OBJ_BLOB && size > big_file_threshold)
 428                buf = fixed_buf;
 429        else
 430                buf = xmalloc(size);
 431
 432        memset(&stream, 0, sizeof(stream));
 433        git_inflate_init(&stream);
 434        stream.next_out = buf;
 435        stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 436
 437        do {
 438                unsigned char *last_out = stream.next_out;
 439                stream.next_in = fill(1);
 440                stream.avail_in = input_len;
 441                status = git_inflate(&stream, 0);
 442                use(input_len - stream.avail_in);
 443                if (sha1)
 444                        git_SHA1_Update(&c, last_out, stream.next_out - last_out);
 445                if (buf == fixed_buf) {
 446                        stream.next_out = buf;
 447                        stream.avail_out = sizeof(fixed_buf);
 448                }
 449        } while (status == Z_OK);
 450        if (stream.total_out != size || status != Z_STREAM_END)
 451                bad_object(offset, _("inflate returned %d"), status);
 452        git_inflate_end(&stream);
 453        if (sha1)
 454                git_SHA1_Final(sha1, &c);
 455        return buf == fixed_buf ? NULL : buf;
 456}
 457
 458static void *unpack_raw_entry(struct object_entry *obj,
 459                              union delta_base *delta_base,
 460                              unsigned char *sha1)
 461{
 462        unsigned char *p;
 463        unsigned long size, c;
 464        off_t base_offset;
 465        unsigned shift;
 466        void *data;
 467
 468        obj->idx.offset = consumed_bytes;
 469        input_crc32 = crc32(0, NULL, 0);
 470
 471        p = fill(1);
 472        c = *p;
 473        use(1);
 474        obj->type = (c >> 4) & 7;
 475        size = (c & 15);
 476        shift = 4;
 477        while (c & 0x80) {
 478                p = fill(1);
 479                c = *p;
 480                use(1);
 481                size += (c & 0x7f) << shift;
 482                shift += 7;
 483        }
 484        obj->size = size;
 485
 486        switch (obj->type) {
 487        case OBJ_REF_DELTA:
 488                hashcpy(delta_base->sha1, fill(20));
 489                use(20);
 490                break;
 491        case OBJ_OFS_DELTA:
 492                memset(delta_base, 0, sizeof(*delta_base));
 493                p = fill(1);
 494                c = *p;
 495                use(1);
 496                base_offset = c & 127;
 497                while (c & 128) {
 498                        base_offset += 1;
 499                        if (!base_offset || MSB(base_offset, 7))
 500                                bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 501                        p = fill(1);
 502                        c = *p;
 503                        use(1);
 504                        base_offset = (base_offset << 7) + (c & 127);
 505                }
 506                delta_base->offset = obj->idx.offset - base_offset;
 507                if (delta_base->offset <= 0 || delta_base->offset >= obj->idx.offset)
 508                        bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 509                break;
 510        case OBJ_COMMIT:
 511        case OBJ_TREE:
 512        case OBJ_BLOB:
 513        case OBJ_TAG:
 514                break;
 515        default:
 516                bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 517        }
 518        obj->hdr_size = consumed_bytes - obj->idx.offset;
 519
 520        data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, sha1);
 521        obj->idx.crc32 = input_crc32;
 522        return data;
 523}
 524
 525static void *unpack_data(struct object_entry *obj,
 526                         int (*consume)(const unsigned char *, unsigned long, void *),
 527                         void *cb_data)
 528{
 529        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 530        unsigned long len = obj[1].idx.offset - from;
 531        unsigned char *data, *inbuf;
 532        git_zstream stream;
 533        int status;
 534
 535        data = xmalloc(consume ? 64*1024 : obj->size);
 536        inbuf = xmalloc((len < 64*1024) ? len : 64*1024);
 537
 538        memset(&stream, 0, sizeof(stream));
 539        git_inflate_init(&stream);
 540        stream.next_out = data;
 541        stream.avail_out = consume ? 64*1024 : obj->size;
 542
 543        do {
 544                ssize_t n = (len < 64*1024) ? len : 64*1024;
 545                n = pread(pack_fd, inbuf, n, from);
 546                if (n < 0)
 547                        die_errno(_("cannot pread pack file"));
 548                if (!n)
 549                        die(Q_("premature end of pack file, %lu byte missing",
 550                               "premature end of pack file, %lu bytes missing",
 551                               len),
 552                            len);
 553                from += n;
 554                len -= n;
 555                stream.next_in = inbuf;
 556                stream.avail_in = n;
 557                if (!consume)
 558                        status = git_inflate(&stream, 0);
 559                else {
 560                        do {
 561                                status = git_inflate(&stream, 0);
 562                                if (consume(data, stream.next_out - data, cb_data)) {
 563                                        free(inbuf);
 564                                        free(data);
 565                                        return NULL;
 566                                }
 567                                stream.next_out = data;
 568                                stream.avail_out = 64*1024;
 569                        } while (status == Z_OK && stream.avail_in);
 570                }
 571        } while (len && status == Z_OK && !stream.avail_in);
 572
 573        /* This has been inflated OK when first encountered, so... */
 574        if (status != Z_STREAM_END || stream.total_out != obj->size)
 575                die(_("serious inflate inconsistency"));
 576
 577        git_inflate_end(&stream);
 578        free(inbuf);
 579        if (consume) {
 580                free(data);
 581                data = NULL;
 582        }
 583        return data;
 584}
 585
 586static void *get_data_from_pack(struct object_entry *obj)
 587{
 588        return unpack_data(obj, NULL, NULL);
 589}
 590
 591static int compare_delta_bases(const union delta_base *base1,
 592                               const union delta_base *base2,
 593                               enum object_type type1,
 594                               enum object_type type2)
 595{
 596        int cmp = type1 - type2;
 597        if (cmp)
 598                return cmp;
 599        return memcmp(base1, base2, UNION_BASE_SZ);
 600}
 601
 602static int find_delta(const union delta_base *base, enum object_type type)
 603{
 604        int first = 0, last = nr_deltas;
 605
 606        while (first < last) {
 607                int next = (first + last) / 2;
 608                struct delta_entry *delta = &deltas[next];
 609                int cmp;
 610
 611                cmp = compare_delta_bases(base, &delta->base,
 612                                          type, objects[delta->obj_no].type);
 613                if (!cmp)
 614                        return next;
 615                if (cmp < 0) {
 616                        last = next;
 617                        continue;
 618                }
 619                first = next+1;
 620        }
 621        return -first-1;
 622}
 623
 624static void find_delta_children(const union delta_base *base,
 625                                int *first_index, int *last_index,
 626                                enum object_type type)
 627{
 628        int first = find_delta(base, type);
 629        int last = first;
 630        int end = nr_deltas - 1;
 631
 632        if (first < 0) {
 633                *first_index = 0;
 634                *last_index = -1;
 635                return;
 636        }
 637        while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
 638                --first;
 639        while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
 640                ++last;
 641        *first_index = first;
 642        *last_index = last;
 643}
 644
 645struct compare_data {
 646        struct object_entry *entry;
 647        struct git_istream *st;
 648        unsigned char *buf;
 649        unsigned long buf_size;
 650};
 651
 652static int compare_objects(const unsigned char *buf, unsigned long size,
 653                           void *cb_data)
 654{
 655        struct compare_data *data = cb_data;
 656
 657        if (data->buf_size < size) {
 658                free(data->buf);
 659                data->buf = xmalloc(size);
 660                data->buf_size = size;
 661        }
 662
 663        while (size) {
 664                ssize_t len = read_istream(data->st, data->buf, size);
 665                if (len == 0)
 666                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 667                            sha1_to_hex(data->entry->idx.sha1));
 668                if (len < 0)
 669                        die(_("unable to read %s"),
 670                            sha1_to_hex(data->entry->idx.sha1));
 671                if (memcmp(buf, data->buf, len))
 672                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 673                            sha1_to_hex(data->entry->idx.sha1));
 674                size -= len;
 675                buf += len;
 676        }
 677        return 0;
 678}
 679
 680static int check_collison(struct object_entry *entry)
 681{
 682        struct compare_data data;
 683        enum object_type type;
 684        unsigned long size;
 685
 686        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 687                return -1;
 688
 689        memset(&data, 0, sizeof(data));
 690        data.entry = entry;
 691        data.st = open_istream(entry->idx.sha1, &type, &size, NULL);
 692        if (!data.st)
 693                return -1;
 694        if (size != entry->size || type != entry->type)
 695                die(_("SHA1 COLLISION FOUND WITH %s !"),
 696                    sha1_to_hex(entry->idx.sha1));
 697        unpack_data(entry, compare_objects, &data);
 698        close_istream(data.st);
 699        free(data.buf);
 700        return 0;
 701}
 702
 703static void sha1_object(const void *data, struct object_entry *obj_entry,
 704                        unsigned long size, enum object_type type,
 705                        const unsigned char *sha1)
 706{
 707        void *new_data = NULL;
 708        int collision_test_needed;
 709
 710        assert(data || obj_entry);
 711
 712        read_lock();
 713        collision_test_needed = has_sha1_file(sha1);
 714        read_unlock();
 715
 716        if (collision_test_needed && !data) {
 717                read_lock();
 718                if (!check_collison(obj_entry))
 719                        collision_test_needed = 0;
 720                read_unlock();
 721        }
 722        if (collision_test_needed) {
 723                void *has_data;
 724                enum object_type has_type;
 725                unsigned long has_size;
 726                read_lock();
 727                has_type = sha1_object_info(sha1, &has_size);
 728                if (has_type != type || has_size != size)
 729                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 730                has_data = read_sha1_file(sha1, &has_type, &has_size);
 731                read_unlock();
 732                if (!data)
 733                        data = new_data = get_data_from_pack(obj_entry);
 734                if (!has_data)
 735                        die(_("cannot read existing object %s"), sha1_to_hex(sha1));
 736                if (size != has_size || type != has_type ||
 737                    memcmp(data, has_data, size) != 0)
 738                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 739                free(has_data);
 740        }
 741
 742        if (strict) {
 743                read_lock();
 744                if (type == OBJ_BLOB) {
 745                        struct blob *blob = lookup_blob(sha1);
 746                        if (blob)
 747                                blob->object.flags |= FLAG_CHECKED;
 748                        else
 749                                die(_("invalid blob object %s"), sha1_to_hex(sha1));
 750                } else {
 751                        struct object *obj;
 752                        int eaten;
 753                        void *buf = (void *) data;
 754
 755                        assert(data && "data can only be NULL for large _blobs_");
 756
 757                        /*
 758                         * we do not need to free the memory here, as the
 759                         * buf is deleted by the caller.
 760                         */
 761                        obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 762                        if (!obj)
 763                                die(_("invalid %s"), typename(type));
 764                        if (do_fsck_object &&
 765                            fsck_object(obj, 1, fsck_error_function))
 766                                die(_("Error in object"));
 767                        if (fsck_walk(obj, mark_link, NULL))
 768                                die(_("Not all child objects of %s are reachable"), sha1_to_hex(obj->sha1));
 769
 770                        if (obj->type == OBJ_TREE) {
 771                                struct tree *item = (struct tree *) obj;
 772                                item->buffer = NULL;
 773                                obj->parsed = 0;
 774                        }
 775                        if (obj->type == OBJ_COMMIT) {
 776                                struct commit *commit = (struct commit *) obj;
 777                                if (detach_commit_buffer(commit) != data)
 778                                        die("BUG: parse_object_buffer transmogrified our buffer");
 779                        }
 780                        obj->flags |= FLAG_CHECKED;
 781                }
 782                read_unlock();
 783        }
 784
 785        free(new_data);
 786}
 787
 788/*
 789 * This function is part of find_unresolved_deltas(). There are two
 790 * walkers going in the opposite ways.
 791 *
 792 * The first one in find_unresolved_deltas() traverses down from
 793 * parent node to children, deflating nodes along the way. However,
 794 * memory for deflated nodes is limited by delta_base_cache_limit, so
 795 * at some point parent node's deflated content may be freed.
 796 *
 797 * The second walker is this function, which goes from current node up
 798 * to top parent if necessary to deflate the node. In normal
 799 * situation, its parent node would be already deflated, so it just
 800 * needs to apply delta.
 801 *
 802 * In the worst case scenario, parent node is no longer deflated because
 803 * we're running out of delta_base_cache_limit; we need to re-deflate
 804 * parents, possibly up to the top base.
 805 *
 806 * All deflated objects here are subject to be freed if we exceed
 807 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 808 * just need to make sure the last node is not freed.
 809 */
 810static void *get_base_data(struct base_data *c)
 811{
 812        if (!c->data) {
 813                struct object_entry *obj = c->obj;
 814                struct base_data **delta = NULL;
 815                int delta_nr = 0, delta_alloc = 0;
 816
 817                while (is_delta_type(c->obj->type) && !c->data) {
 818                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 819                        delta[delta_nr++] = c;
 820                        c = c->base;
 821                }
 822                if (!delta_nr) {
 823                        c->data = get_data_from_pack(obj);
 824                        c->size = obj->size;
 825                        get_thread_data()->base_cache_used += c->size;
 826                        prune_base_data(c);
 827                }
 828                for (; delta_nr > 0; delta_nr--) {
 829                        void *base, *raw;
 830                        c = delta[delta_nr - 1];
 831                        obj = c->obj;
 832                        base = get_base_data(c->base);
 833                        raw = get_data_from_pack(obj);
 834                        c->data = patch_delta(
 835                                base, c->base->size,
 836                                raw, obj->size,
 837                                &c->size);
 838                        free(raw);
 839                        if (!c->data)
 840                                bad_object(obj->idx.offset, _("failed to apply delta"));
 841                        get_thread_data()->base_cache_used += c->size;
 842                        prune_base_data(c);
 843                }
 844                free(delta);
 845        }
 846        return c->data;
 847}
 848
 849static void resolve_delta(struct object_entry *delta_obj,
 850                          struct base_data *base, struct base_data *result)
 851{
 852        void *base_data, *delta_data;
 853
 854        delta_obj->real_type = base->obj->real_type;
 855        if (show_stat) {
 856                delta_obj->delta_depth = base->obj->delta_depth + 1;
 857                deepest_delta_lock();
 858                if (deepest_delta < delta_obj->delta_depth)
 859                        deepest_delta = delta_obj->delta_depth;
 860                deepest_delta_unlock();
 861        }
 862        delta_obj->base_object_no = base->obj - objects;
 863        delta_data = get_data_from_pack(delta_obj);
 864        base_data = get_base_data(base);
 865        result->obj = delta_obj;
 866        result->data = patch_delta(base_data, base->size,
 867                                   delta_data, delta_obj->size, &result->size);
 868        free(delta_data);
 869        if (!result->data)
 870                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 871        hash_sha1_file(result->data, result->size,
 872                       typename(delta_obj->real_type), delta_obj->idx.sha1);
 873        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 874                    delta_obj->idx.sha1);
 875        counter_lock();
 876        nr_resolved_deltas++;
 877        counter_unlock();
 878}
 879
 880static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 881                                                  struct base_data *prev_base)
 882{
 883        if (base->ref_last == -1 && base->ofs_last == -1) {
 884                union delta_base base_spec;
 885
 886                hashcpy(base_spec.sha1, base->obj->idx.sha1);
 887                find_delta_children(&base_spec,
 888                                    &base->ref_first, &base->ref_last, OBJ_REF_DELTA);
 889
 890                memset(&base_spec, 0, sizeof(base_spec));
 891                base_spec.offset = base->obj->idx.offset;
 892                find_delta_children(&base_spec,
 893                                    &base->ofs_first, &base->ofs_last, OBJ_OFS_DELTA);
 894
 895                if (base->ref_last == -1 && base->ofs_last == -1) {
 896                        free(base->data);
 897                        return NULL;
 898                }
 899
 900                link_base_data(prev_base, base);
 901        }
 902
 903        if (base->ref_first <= base->ref_last) {
 904                struct object_entry *child = objects + deltas[base->ref_first].obj_no;
 905                struct base_data *result = alloc_base_data();
 906
 907                assert(child->real_type == OBJ_REF_DELTA);
 908                resolve_delta(child, base, result);
 909                if (base->ref_first == base->ref_last && base->ofs_last == -1)
 910                        free_base_data(base);
 911
 912                base->ref_first++;
 913                return result;
 914        }
 915
 916        if (base->ofs_first <= base->ofs_last) {
 917                struct object_entry *child = objects + deltas[base->ofs_first].obj_no;
 918                struct base_data *result = alloc_base_data();
 919
 920                assert(child->real_type == OBJ_OFS_DELTA);
 921                resolve_delta(child, base, result);
 922                if (base->ofs_first == base->ofs_last)
 923                        free_base_data(base);
 924
 925                base->ofs_first++;
 926                return result;
 927        }
 928
 929        unlink_base_data(base);
 930        return NULL;
 931}
 932
 933static void find_unresolved_deltas(struct base_data *base)
 934{
 935        struct base_data *new_base, *prev_base = NULL;
 936        for (;;) {
 937                new_base = find_unresolved_deltas_1(base, prev_base);
 938
 939                if (new_base) {
 940                        prev_base = base;
 941                        base = new_base;
 942                } else {
 943                        free(base);
 944                        base = prev_base;
 945                        if (!base)
 946                                return;
 947                        prev_base = base->base;
 948                }
 949        }
 950}
 951
 952static int compare_delta_entry(const void *a, const void *b)
 953{
 954        const struct delta_entry *delta_a = a;
 955        const struct delta_entry *delta_b = b;
 956
 957        /* group by type (ref vs ofs) and then by value (sha-1 or offset) */
 958        return compare_delta_bases(&delta_a->base, &delta_b->base,
 959                                   objects[delta_a->obj_no].type,
 960                                   objects[delta_b->obj_no].type);
 961}
 962
 963static void resolve_base(struct object_entry *obj)
 964{
 965        struct base_data *base_obj = alloc_base_data();
 966        base_obj->obj = obj;
 967        base_obj->data = NULL;
 968        find_unresolved_deltas(base_obj);
 969}
 970
 971#ifndef NO_PTHREADS
 972static void *threaded_second_pass(void *data)
 973{
 974        set_thread_data(data);
 975        for (;;) {
 976                int i;
 977                counter_lock();
 978                display_progress(progress, nr_resolved_deltas);
 979                counter_unlock();
 980                work_lock();
 981                while (nr_dispatched < nr_objects &&
 982                       is_delta_type(objects[nr_dispatched].type))
 983                        nr_dispatched++;
 984                if (nr_dispatched >= nr_objects) {
 985                        work_unlock();
 986                        break;
 987                }
 988                i = nr_dispatched++;
 989                work_unlock();
 990
 991                resolve_base(&objects[i]);
 992        }
 993        return NULL;
 994}
 995#endif
 996
 997/*
 998 * First pass:
 999 * - find locations of all objects;
1000 * - calculate SHA1 of all non-delta objects;
1001 * - remember base (SHA1 or offset) for all deltas.
1002 */
1003static void parse_pack_objects(unsigned char *sha1)
1004{
1005        int i, nr_delays = 0;
1006        struct delta_entry *delta = deltas;
1007        struct stat st;
1008
1009        if (verbose)
1010                progress = start_progress(
1011                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1012                                nr_objects);
1013        for (i = 0; i < nr_objects; i++) {
1014                struct object_entry *obj = &objects[i];
1015                void *data = unpack_raw_entry(obj, &delta->base, obj->idx.sha1);
1016                obj->real_type = obj->type;
1017                if (is_delta_type(obj->type)) {
1018                        nr_deltas++;
1019                        delta->obj_no = i;
1020                        delta++;
1021                } else if (!data) {
1022                        /* large blobs, check later */
1023                        obj->real_type = OBJ_BAD;
1024                        nr_delays++;
1025                } else
1026                        sha1_object(data, NULL, obj->size, obj->type, obj->idx.sha1);
1027                free(data);
1028                display_progress(progress, i+1);
1029        }
1030        objects[i].idx.offset = consumed_bytes;
1031        stop_progress(&progress);
1032
1033        /* Check pack integrity */
1034        flush();
1035        git_SHA1_Final(sha1, &input_ctx);
1036        if (hashcmp(fill(20), sha1))
1037                die(_("pack is corrupted (SHA1 mismatch)"));
1038        use(20);
1039
1040        /* If input_fd is a file, we should have reached its end now. */
1041        if (fstat(input_fd, &st))
1042                die_errno(_("cannot fstat packfile"));
1043        if (S_ISREG(st.st_mode) &&
1044                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1045                die(_("pack has junk at the end"));
1046
1047        for (i = 0; i < nr_objects; i++) {
1048                struct object_entry *obj = &objects[i];
1049                if (obj->real_type != OBJ_BAD)
1050                        continue;
1051                obj->real_type = obj->type;
1052                sha1_object(NULL, obj, obj->size, obj->type, obj->idx.sha1);
1053                nr_delays--;
1054        }
1055        if (nr_delays)
1056                die(_("confusion beyond insanity in parse_pack_objects()"));
1057}
1058
1059/*
1060 * Second pass:
1061 * - for all non-delta objects, look if it is used as a base for
1062 *   deltas;
1063 * - if used as a base, uncompress the object and apply all deltas,
1064 *   recursively checking if the resulting object is used as a base
1065 *   for some more deltas.
1066 */
1067static void resolve_deltas(void)
1068{
1069        int i;
1070
1071        if (!nr_deltas)
1072                return;
1073
1074        /* Sort deltas by base SHA1/offset for fast searching */
1075        qsort(deltas, nr_deltas, sizeof(struct delta_entry),
1076              compare_delta_entry);
1077
1078        if (verbose)
1079                progress = start_progress(_("Resolving deltas"), nr_deltas);
1080
1081#ifndef NO_PTHREADS
1082        nr_dispatched = 0;
1083        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1084                init_thread();
1085                for (i = 0; i < nr_threads; i++) {
1086                        int ret = pthread_create(&thread_data[i].thread, NULL,
1087                                                 threaded_second_pass, thread_data + i);
1088                        if (ret)
1089                                die(_("unable to create thread: %s"),
1090                                    strerror(ret));
1091                }
1092                for (i = 0; i < nr_threads; i++)
1093                        pthread_join(thread_data[i].thread, NULL);
1094                cleanup_thread();
1095                return;
1096        }
1097#endif
1098
1099        for (i = 0; i < nr_objects; i++) {
1100                struct object_entry *obj = &objects[i];
1101
1102                if (is_delta_type(obj->type))
1103                        continue;
1104                resolve_base(obj);
1105                display_progress(progress, nr_resolved_deltas);
1106        }
1107}
1108
1109/*
1110 * Third pass:
1111 * - append objects to convert thin pack to full pack if required
1112 * - write the final 20-byte SHA-1
1113 */
1114static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved);
1115static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
1116{
1117        if (nr_deltas == nr_resolved_deltas) {
1118                stop_progress(&progress);
1119                /* Flush remaining pack final 20-byte SHA1. */
1120                flush();
1121                return;
1122        }
1123
1124        if (fix_thin_pack) {
1125                struct sha1file *f;
1126                unsigned char read_sha1[20], tail_sha1[20];
1127                struct strbuf msg = STRBUF_INIT;
1128                int nr_unresolved = nr_deltas - nr_resolved_deltas;
1129                int nr_objects_initial = nr_objects;
1130                if (nr_unresolved <= 0)
1131                        die(_("confusion beyond insanity"));
1132                objects = xrealloc(objects,
1133                                   (nr_objects + nr_unresolved + 1)
1134                                   * sizeof(*objects));
1135                memset(objects + nr_objects + 1, 0,
1136                       nr_unresolved * sizeof(*objects));
1137                f = sha1fd(output_fd, curr_pack);
1138                fix_unresolved_deltas(f, nr_unresolved);
1139                strbuf_addf(&msg, _("completed with %d local objects"),
1140                            nr_objects - nr_objects_initial);
1141                stop_progress_msg(&progress, msg.buf);
1142                strbuf_release(&msg);
1143                sha1close(f, tail_sha1, 0);
1144                hashcpy(read_sha1, pack_sha1);
1145                fixup_pack_header_footer(output_fd, pack_sha1,
1146                                         curr_pack, nr_objects,
1147                                         read_sha1, consumed_bytes-20);
1148                if (hashcmp(read_sha1, tail_sha1) != 0)
1149                        die(_("Unexpected tail checksum for %s "
1150                              "(disk corruption?)"), curr_pack);
1151        }
1152        if (nr_deltas != nr_resolved_deltas)
1153                die(Q_("pack has %d unresolved delta",
1154                       "pack has %d unresolved deltas",
1155                       nr_deltas - nr_resolved_deltas),
1156                    nr_deltas - nr_resolved_deltas);
1157}
1158
1159static int write_compressed(struct sha1file *f, void *in, unsigned int size)
1160{
1161        git_zstream stream;
1162        int status;
1163        unsigned char outbuf[4096];
1164
1165        memset(&stream, 0, sizeof(stream));
1166        git_deflate_init(&stream, zlib_compression_level);
1167        stream.next_in = in;
1168        stream.avail_in = size;
1169
1170        do {
1171                stream.next_out = outbuf;
1172                stream.avail_out = sizeof(outbuf);
1173                status = git_deflate(&stream, Z_FINISH);
1174                sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
1175        } while (status == Z_OK);
1176
1177        if (status != Z_STREAM_END)
1178                die(_("unable to deflate appended object (%d)"), status);
1179        size = stream.total_out;
1180        git_deflate_end(&stream);
1181        return size;
1182}
1183
1184static struct object_entry *append_obj_to_pack(struct sha1file *f,
1185                               const unsigned char *sha1, void *buf,
1186                               unsigned long size, enum object_type type)
1187{
1188        struct object_entry *obj = &objects[nr_objects++];
1189        unsigned char header[10];
1190        unsigned long s = size;
1191        int n = 0;
1192        unsigned char c = (type << 4) | (s & 15);
1193        s >>= 4;
1194        while (s) {
1195                header[n++] = c | 0x80;
1196                c = s & 0x7f;
1197                s >>= 7;
1198        }
1199        header[n++] = c;
1200        crc32_begin(f);
1201        sha1write(f, header, n);
1202        obj[0].size = size;
1203        obj[0].hdr_size = n;
1204        obj[0].type = type;
1205        obj[0].real_type = type;
1206        obj[1].idx.offset = obj[0].idx.offset + n;
1207        obj[1].idx.offset += write_compressed(f, buf, size);
1208        obj[0].idx.crc32 = crc32_end(f);
1209        sha1flush(f);
1210        hashcpy(obj->idx.sha1, sha1);
1211        return obj;
1212}
1213
1214static int delta_pos_compare(const void *_a, const void *_b)
1215{
1216        struct delta_entry *a = *(struct delta_entry **)_a;
1217        struct delta_entry *b = *(struct delta_entry **)_b;
1218        return a->obj_no - b->obj_no;
1219}
1220
1221static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
1222{
1223        struct delta_entry **sorted_by_pos;
1224        int i, n = 0;
1225
1226        /*
1227         * Since many unresolved deltas may well be themselves base objects
1228         * for more unresolved deltas, we really want to include the
1229         * smallest number of base objects that would cover as much delta
1230         * as possible by picking the
1231         * trunc deltas first, allowing for other deltas to resolve without
1232         * additional base objects.  Since most base objects are to be found
1233         * before deltas depending on them, a good heuristic is to start
1234         * resolving deltas in the same order as their position in the pack.
1235         */
1236        sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
1237        for (i = 0; i < nr_deltas; i++) {
1238                if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
1239                        continue;
1240                sorted_by_pos[n++] = &deltas[i];
1241        }
1242        qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
1243
1244        for (i = 0; i < n; i++) {
1245                struct delta_entry *d = sorted_by_pos[i];
1246                enum object_type type;
1247                struct base_data *base_obj = alloc_base_data();
1248
1249                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1250                        continue;
1251                base_obj->data = read_sha1_file(d->base.sha1, &type, &base_obj->size);
1252                if (!base_obj->data)
1253                        continue;
1254
1255                if (check_sha1_signature(d->base.sha1, base_obj->data,
1256                                base_obj->size, typename(type)))
1257                        die(_("local object %s is corrupt"), sha1_to_hex(d->base.sha1));
1258                base_obj->obj = append_obj_to_pack(f, d->base.sha1,
1259                                        base_obj->data, base_obj->size, type);
1260                find_unresolved_deltas(base_obj);
1261                display_progress(progress, nr_resolved_deltas);
1262        }
1263        free(sorted_by_pos);
1264}
1265
1266static void final(const char *final_pack_name, const char *curr_pack_name,
1267                  const char *final_index_name, const char *curr_index_name,
1268                  const char *keep_name, const char *keep_msg,
1269                  unsigned char *sha1)
1270{
1271        const char *report = "pack";
1272        char name[PATH_MAX];
1273        int err;
1274
1275        if (!from_stdin) {
1276                close(input_fd);
1277        } else {
1278                fsync_or_die(output_fd, curr_pack_name);
1279                err = close(output_fd);
1280                if (err)
1281                        die_errno(_("error while closing pack file"));
1282        }
1283
1284        if (keep_msg) {
1285                int keep_fd, keep_msg_len = strlen(keep_msg);
1286
1287                if (!keep_name)
1288                        keep_fd = odb_pack_keep(name, sizeof(name), sha1);
1289                else
1290                        keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
1291
1292                if (keep_fd < 0) {
1293                        if (errno != EEXIST)
1294                                die_errno(_("cannot write keep file '%s'"),
1295                                          keep_name ? keep_name : name);
1296                } else {
1297                        if (keep_msg_len > 0) {
1298                                write_or_die(keep_fd, keep_msg, keep_msg_len);
1299                                write_or_die(keep_fd, "\n", 1);
1300                        }
1301                        if (close(keep_fd) != 0)
1302                                die_errno(_("cannot close written keep file '%s'"),
1303                                          keep_name ? keep_name : name);
1304                        report = "keep";
1305                }
1306        }
1307
1308        if (final_pack_name != curr_pack_name) {
1309                if (!final_pack_name) {
1310                        snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
1311                                 get_object_directory(), sha1_to_hex(sha1));
1312                        final_pack_name = name;
1313                }
1314                if (move_temp_to_file(curr_pack_name, final_pack_name))
1315                        die(_("cannot store pack file"));
1316        } else if (from_stdin)
1317                chmod(final_pack_name, 0444);
1318
1319        if (final_index_name != curr_index_name) {
1320                if (!final_index_name) {
1321                        snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
1322                                 get_object_directory(), sha1_to_hex(sha1));
1323                        final_index_name = name;
1324                }
1325                if (move_temp_to_file(curr_index_name, final_index_name))
1326                        die(_("cannot store index file"));
1327        } else
1328                chmod(final_index_name, 0444);
1329
1330        if (!from_stdin) {
1331                printf("%s\n", sha1_to_hex(sha1));
1332        } else {
1333                char buf[48];
1334                int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
1335                                   report, sha1_to_hex(sha1));
1336                write_or_die(1, buf, len);
1337
1338                /*
1339                 * Let's just mimic git-unpack-objects here and write
1340                 * the last part of the input buffer to stdout.
1341                 */
1342                while (input_len) {
1343                        err = xwrite(1, input_buffer + input_offset, input_len);
1344                        if (err <= 0)
1345                                break;
1346                        input_len -= err;
1347                        input_offset += err;
1348                }
1349        }
1350}
1351
1352static int git_index_pack_config(const char *k, const char *v, void *cb)
1353{
1354        struct pack_idx_option *opts = cb;
1355
1356        if (!strcmp(k, "pack.indexversion")) {
1357                opts->version = git_config_int(k, v);
1358                if (opts->version > 2)
1359                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1360                return 0;
1361        }
1362        if (!strcmp(k, "pack.threads")) {
1363                nr_threads = git_config_int(k, v);
1364                if (nr_threads < 0)
1365                        die(_("invalid number of threads specified (%d)"),
1366                            nr_threads);
1367#ifdef NO_PTHREADS
1368                if (nr_threads != 1)
1369                        warning(_("no threads support, ignoring %s"), k);
1370                nr_threads = 1;
1371#endif
1372                return 0;
1373        }
1374        return git_default_config(k, v, cb);
1375}
1376
1377static int cmp_uint32(const void *a_, const void *b_)
1378{
1379        uint32_t a = *((uint32_t *)a_);
1380        uint32_t b = *((uint32_t *)b_);
1381
1382        return (a < b) ? -1 : (a != b);
1383}
1384
1385static void read_v2_anomalous_offsets(struct packed_git *p,
1386                                      struct pack_idx_option *opts)
1387{
1388        const uint32_t *idx1, *idx2;
1389        uint32_t i;
1390
1391        /* The address of the 4-byte offset table */
1392        idx1 = (((const uint32_t *)p->index_data)
1393                + 2 /* 8-byte header */
1394                + 256 /* fan out */
1395                + 5 * p->num_objects /* 20-byte SHA-1 table */
1396                + p->num_objects /* CRC32 table */
1397                );
1398
1399        /* The address of the 8-byte offset table */
1400        idx2 = idx1 + p->num_objects;
1401
1402        for (i = 0; i < p->num_objects; i++) {
1403                uint32_t off = ntohl(idx1[i]);
1404                if (!(off & 0x80000000))
1405                        continue;
1406                off = off & 0x7fffffff;
1407                if (idx2[off * 2])
1408                        continue;
1409                /*
1410                 * The real offset is ntohl(idx2[off * 2]) in high 4
1411                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1412                 * octets.  But idx2[off * 2] is Zero!!!
1413                 */
1414                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1415                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1416        }
1417
1418        if (1 < opts->anomaly_nr)
1419                qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
1420}
1421
1422static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1423{
1424        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1425
1426        if (!p)
1427                die(_("Cannot open existing pack file '%s'"), pack_name);
1428        if (open_pack_index(p))
1429                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1430
1431        /* Read the attributes from the existing idx file */
1432        opts->version = p->index_version;
1433
1434        if (opts->version == 2)
1435                read_v2_anomalous_offsets(p, opts);
1436
1437        /*
1438         * Get rid of the idx file as we do not need it anymore.
1439         * NEEDSWORK: extract this bit from free_pack_by_name() in
1440         * sha1_file.c, perhaps?  It shouldn't matter very much as we
1441         * know we haven't installed this pack (hence we never have
1442         * read anything from it).
1443         */
1444        close_pack_index(p);
1445        free(p);
1446}
1447
1448static void show_pack_info(int stat_only)
1449{
1450        int i, baseobjects = nr_objects - nr_deltas;
1451        unsigned long *chain_histogram = NULL;
1452
1453        if (deepest_delta)
1454                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1455
1456        for (i = 0; i < nr_objects; i++) {
1457                struct object_entry *obj = &objects[i];
1458
1459                if (is_delta_type(obj->type))
1460                        chain_histogram[obj->delta_depth - 1]++;
1461                if (stat_only)
1462                        continue;
1463                printf("%s %-6s %lu %lu %"PRIuMAX,
1464                       sha1_to_hex(obj->idx.sha1),
1465                       typename(obj->real_type), obj->size,
1466                       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1467                       (uintmax_t)obj->idx.offset);
1468                if (is_delta_type(obj->type)) {
1469                        struct object_entry *bobj = &objects[obj->base_object_no];
1470                        printf(" %u %s", obj->delta_depth, sha1_to_hex(bobj->idx.sha1));
1471                }
1472                putchar('\n');
1473        }
1474
1475        if (baseobjects)
1476                printf_ln(Q_("non delta: %d object",
1477                             "non delta: %d objects",
1478                             baseobjects),
1479                          baseobjects);
1480        for (i = 0; i < deepest_delta; i++) {
1481                if (!chain_histogram[i])
1482                        continue;
1483                printf_ln(Q_("chain length = %d: %lu object",
1484                             "chain length = %d: %lu objects",
1485                             chain_histogram[i]),
1486                          i + 1,
1487                          chain_histogram[i]);
1488        }
1489}
1490
1491int cmd_index_pack(int argc, const char **argv, const char *prefix)
1492{
1493        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1494        const char *curr_pack, *curr_index;
1495        const char *index_name = NULL, *pack_name = NULL;
1496        const char *keep_name = NULL, *keep_msg = NULL;
1497        char *index_name_buf = NULL, *keep_name_buf = NULL;
1498        struct pack_idx_entry **idx_objects;
1499        struct pack_idx_option opts;
1500        unsigned char pack_sha1[20];
1501        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1502
1503        if (argc == 2 && !strcmp(argv[1], "-h"))
1504                usage(index_pack_usage);
1505
1506        check_replace_refs = 0;
1507
1508        reset_pack_idx_option(&opts);
1509        git_config(git_index_pack_config, &opts);
1510        if (prefix && chdir(prefix))
1511                die(_("Cannot come back to cwd"));
1512
1513        for (i = 1; i < argc; i++) {
1514                const char *arg = argv[i];
1515
1516                if (*arg == '-') {
1517                        if (!strcmp(arg, "--stdin")) {
1518                                from_stdin = 1;
1519                        } else if (!strcmp(arg, "--fix-thin")) {
1520                                fix_thin_pack = 1;
1521                        } else if (!strcmp(arg, "--strict")) {
1522                                strict = 1;
1523                                do_fsck_object = 1;
1524                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1525                                strict = 1;
1526                                check_self_contained_and_connected = 1;
1527                        } else if (!strcmp(arg, "--verify")) {
1528                                verify = 1;
1529                        } else if (!strcmp(arg, "--verify-stat")) {
1530                                verify = 1;
1531                                show_stat = 1;
1532                        } else if (!strcmp(arg, "--verify-stat-only")) {
1533                                verify = 1;
1534                                show_stat = 1;
1535                                stat_only = 1;
1536                        } else if (!strcmp(arg, "--keep")) {
1537                                keep_msg = "";
1538                        } else if (starts_with(arg, "--keep=")) {
1539                                keep_msg = arg + 7;
1540                        } else if (starts_with(arg, "--threads=")) {
1541                                char *end;
1542                                nr_threads = strtoul(arg+10, &end, 0);
1543                                if (!arg[10] || *end || nr_threads < 0)
1544                                        usage(index_pack_usage);
1545#ifdef NO_PTHREADS
1546                                if (nr_threads != 1)
1547                                        warning(_("no threads support, "
1548                                                  "ignoring %s"), arg);
1549                                nr_threads = 1;
1550#endif
1551                        } else if (starts_with(arg, "--pack_header=")) {
1552                                struct pack_header *hdr;
1553                                char *c;
1554
1555                                hdr = (struct pack_header *)input_buffer;
1556                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1557                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1558                                if (*c != ',')
1559                                        die(_("bad %s"), arg);
1560                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1561                                if (*c)
1562                                        die(_("bad %s"), arg);
1563                                input_len = sizeof(*hdr);
1564                        } else if (!strcmp(arg, "-v")) {
1565                                verbose = 1;
1566                        } else if (!strcmp(arg, "-o")) {
1567                                if (index_name || (i+1) >= argc)
1568                                        usage(index_pack_usage);
1569                                index_name = argv[++i];
1570                        } else if (starts_with(arg, "--index-version=")) {
1571                                char *c;
1572                                opts.version = strtoul(arg + 16, &c, 10);
1573                                if (opts.version > 2)
1574                                        die(_("bad %s"), arg);
1575                                if (*c == ',')
1576                                        opts.off32_limit = strtoul(c+1, &c, 0);
1577                                if (*c || opts.off32_limit & 0x80000000)
1578                                        die(_("bad %s"), arg);
1579                        } else
1580                                usage(index_pack_usage);
1581                        continue;
1582                }
1583
1584                if (pack_name)
1585                        usage(index_pack_usage);
1586                pack_name = arg;
1587        }
1588
1589        if (!pack_name && !from_stdin)
1590                usage(index_pack_usage);
1591        if (fix_thin_pack && !from_stdin)
1592                die(_("--fix-thin cannot be used without --stdin"));
1593        if (!index_name && pack_name) {
1594                int len = strlen(pack_name);
1595                if (!has_extension(pack_name, ".pack"))
1596                        die(_("packfile name '%s' does not end with '.pack'"),
1597                            pack_name);
1598                index_name_buf = xmalloc(len);
1599                memcpy(index_name_buf, pack_name, len - 5);
1600                strcpy(index_name_buf + len - 5, ".idx");
1601                index_name = index_name_buf;
1602        }
1603        if (keep_msg && !keep_name && pack_name) {
1604                int len = strlen(pack_name);
1605                if (!has_extension(pack_name, ".pack"))
1606                        die(_("packfile name '%s' does not end with '.pack'"),
1607                            pack_name);
1608                keep_name_buf = xmalloc(len);
1609                memcpy(keep_name_buf, pack_name, len - 5);
1610                strcpy(keep_name_buf + len - 5, ".keep");
1611                keep_name = keep_name_buf;
1612        }
1613        if (verify) {
1614                if (!index_name)
1615                        die(_("--verify with no packfile name given"));
1616                read_idx_option(&opts, index_name);
1617                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1618        }
1619        if (strict)
1620                opts.flags |= WRITE_IDX_STRICT;
1621
1622#ifndef NO_PTHREADS
1623        if (!nr_threads) {
1624                nr_threads = online_cpus();
1625                /* An experiment showed that more threads does not mean faster */
1626                if (nr_threads > 3)
1627                        nr_threads = 3;
1628        }
1629#endif
1630
1631        curr_pack = open_pack_file(pack_name);
1632        parse_pack_header();
1633        objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
1634        deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
1635        parse_pack_objects(pack_sha1);
1636        resolve_deltas();
1637        conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1638        free(deltas);
1639        if (strict)
1640                foreign_nr = check_objects();
1641
1642        if (show_stat)
1643                show_pack_info(stat_only);
1644
1645        idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
1646        for (i = 0; i < nr_objects; i++)
1647                idx_objects[i] = &objects[i].idx;
1648        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1649        free(idx_objects);
1650
1651        if (!verify)
1652                final(pack_name, curr_pack,
1653                      index_name, curr_index,
1654                      keep_name, keep_msg,
1655                      pack_sha1);
1656        else
1657                close(input_fd);
1658        free(objects);
1659        free(index_name_buf);
1660        free(keep_name_buf);
1661        if (pack_name == NULL)
1662                free((void *) curr_pack);
1663        if (index_name == NULL)
1664                free((void *) curr_index);
1665
1666        /*
1667         * Let the caller know this pack is not self contained
1668         */
1669        if (check_self_contained_and_connected && foreign_nr)
1670                return 1;
1671
1672        return 0;
1673}