9d854fb751931840449b2d5dc0b30c9edcb6164c
   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 char hdr_size;
  22        signed char type;
  23        signed char real_type;
  24};
  25
  26struct object_stat {
  27        unsigned delta_depth;
  28        int base_object_no;
  29};
  30
  31union delta_base {
  32        unsigned char sha1[20];
  33        off_t offset;
  34};
  35
  36struct base_data {
  37        struct base_data *base;
  38        struct base_data *child;
  39        struct object_entry *obj;
  40        void *data;
  41        unsigned long size;
  42        int ref_first, ref_last;
  43        int ofs_first, ofs_last;
  44};
  45
  46struct thread_local {
  47#ifndef NO_PTHREADS
  48        pthread_t thread;
  49#endif
  50        struct base_data *base_cache;
  51        size_t base_cache_used;
  52        int pack_fd;
  53};
  54
  55/*
  56 * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
  57 * to memcmp() only the first 20 bytes.
  58 */
  59#define UNION_BASE_SZ   20
  60
  61#define FLAG_LINK (1u<<20)
  62#define FLAG_CHECKED (1u<<21)
  63
  64struct delta_entry {
  65        union delta_base base;
  66        int obj_no;
  67};
  68
  69static struct object_entry *objects;
  70static struct object_stat *obj_stat;
  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;
  95static const char *curr_pack;
  96
  97#ifndef NO_PTHREADS
  98
  99static struct thread_local *thread_data;
 100static int nr_dispatched;
 101static int threads_active;
 102
 103static pthread_mutex_t read_mutex;
 104#define read_lock()             lock_mutex(&read_mutex)
 105#define read_unlock()           unlock_mutex(&read_mutex)
 106
 107static pthread_mutex_t counter_mutex;
 108#define counter_lock()          lock_mutex(&counter_mutex)
 109#define counter_unlock()        unlock_mutex(&counter_mutex)
 110
 111static pthread_mutex_t work_mutex;
 112#define work_lock()             lock_mutex(&work_mutex)
 113#define work_unlock()           unlock_mutex(&work_mutex)
 114
 115static pthread_mutex_t deepest_delta_mutex;
 116#define deepest_delta_lock()    lock_mutex(&deepest_delta_mutex)
 117#define deepest_delta_unlock()  unlock_mutex(&deepest_delta_mutex)
 118
 119static pthread_mutex_t type_cas_mutex;
 120#define type_cas_lock()         lock_mutex(&type_cas_mutex)
 121#define type_cas_unlock()       unlock_mutex(&type_cas_mutex)
 122
 123static pthread_key_t key;
 124
 125static inline void lock_mutex(pthread_mutex_t *mutex)
 126{
 127        if (threads_active)
 128                pthread_mutex_lock(mutex);
 129}
 130
 131static inline void unlock_mutex(pthread_mutex_t *mutex)
 132{
 133        if (threads_active)
 134                pthread_mutex_unlock(mutex);
 135}
 136
 137/*
 138 * Mutex and conditional variable can't be statically-initialized on Windows.
 139 */
 140static void init_thread(void)
 141{
 142        int i;
 143        init_recursive_mutex(&read_mutex);
 144        pthread_mutex_init(&counter_mutex, NULL);
 145        pthread_mutex_init(&work_mutex, NULL);
 146        pthread_mutex_init(&type_cas_mutex, NULL);
 147        if (show_stat)
 148                pthread_mutex_init(&deepest_delta_mutex, NULL);
 149        pthread_key_create(&key, NULL);
 150        thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 151        for (i = 0; i < nr_threads; i++) {
 152                thread_data[i].pack_fd = open(curr_pack, O_RDONLY);
 153                if (thread_data[i].pack_fd == -1)
 154                        die_errno(_("unable to open %s"), curr_pack);
 155        }
 156
 157        threads_active = 1;
 158}
 159
 160static void cleanup_thread(void)
 161{
 162        int i;
 163        if (!threads_active)
 164                return;
 165        threads_active = 0;
 166        pthread_mutex_destroy(&read_mutex);
 167        pthread_mutex_destroy(&counter_mutex);
 168        pthread_mutex_destroy(&work_mutex);
 169        pthread_mutex_destroy(&type_cas_mutex);
 170        if (show_stat)
 171                pthread_mutex_destroy(&deepest_delta_mutex);
 172        for (i = 0; i < nr_threads; i++)
 173                close(thread_data[i].pack_fd);
 174        pthread_key_delete(key);
 175        free(thread_data);
 176}
 177
 178#else
 179
 180#define read_lock()
 181#define read_unlock()
 182
 183#define counter_lock()
 184#define counter_unlock()
 185
 186#define work_lock()
 187#define work_unlock()
 188
 189#define deepest_delta_lock()
 190#define deepest_delta_unlock()
 191
 192#define type_cas_lock()
 193#define type_cas_unlock()
 194
 195#endif
 196
 197
 198static int mark_link(struct object *obj, int type, void *data)
 199{
 200        if (!obj)
 201                return -1;
 202
 203        if (type != OBJ_ANY && obj->type != type)
 204                die(_("object type mismatch at %s"), sha1_to_hex(obj->sha1));
 205
 206        obj->flags |= FLAG_LINK;
 207        return 0;
 208}
 209
 210/* The content of each linked object must have been checked
 211   or it must be already present in the object database */
 212static unsigned check_object(struct object *obj)
 213{
 214        if (!obj)
 215                return 0;
 216
 217        if (!(obj->flags & FLAG_LINK))
 218                return 0;
 219
 220        if (!(obj->flags & FLAG_CHECKED)) {
 221                unsigned long size;
 222                int type = sha1_object_info(obj->sha1, &size);
 223                if (type <= 0)
 224                        die(_("did not receive expected object %s"),
 225                              sha1_to_hex(obj->sha1));
 226                if (type != obj->type)
 227                        die(_("object %s: expected type %s, found %s"),
 228                            sha1_to_hex(obj->sha1),
 229                            typename(obj->type), typename(type));
 230                obj->flags |= FLAG_CHECKED;
 231                return 1;
 232        }
 233
 234        return 0;
 235}
 236
 237static unsigned check_objects(void)
 238{
 239        unsigned i, max, foreign_nr = 0;
 240
 241        max = get_max_object_index();
 242        for (i = 0; i < max; i++)
 243                foreign_nr += check_object(get_indexed_object(i));
 244        return foreign_nr;
 245}
 246
 247
 248/* Discard current buffer used content. */
 249static void flush(void)
 250{
 251        if (input_offset) {
 252                if (output_fd >= 0)
 253                        write_or_die(output_fd, input_buffer, input_offset);
 254                git_SHA1_Update(&input_ctx, input_buffer, input_offset);
 255                memmove(input_buffer, input_buffer + input_offset, input_len);
 256                input_offset = 0;
 257        }
 258}
 259
 260/*
 261 * Make sure at least "min" bytes are available in the buffer, and
 262 * return the pointer to the buffer.
 263 */
 264static void *fill(int min)
 265{
 266        if (min <= input_len)
 267                return input_buffer + input_offset;
 268        if (min > sizeof(input_buffer))
 269                die(Q_("cannot fill %d byte",
 270                       "cannot fill %d bytes",
 271                       min),
 272                    min);
 273        flush();
 274        do {
 275                ssize_t ret = xread(input_fd, input_buffer + input_len,
 276                                sizeof(input_buffer) - input_len);
 277                if (ret <= 0) {
 278                        if (!ret)
 279                                die(_("early EOF"));
 280                        die_errno(_("read error on input"));
 281                }
 282                input_len += ret;
 283                if (from_stdin)
 284                        display_throughput(progress, consumed_bytes + input_len);
 285        } while (input_len < min);
 286        return input_buffer;
 287}
 288
 289static void use(int bytes)
 290{
 291        if (bytes > input_len)
 292                die(_("used more bytes than were available"));
 293        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 294        input_len -= bytes;
 295        input_offset += bytes;
 296
 297        /* make sure off_t is sufficiently large not to wrap */
 298        if (signed_add_overflows(consumed_bytes, bytes))
 299                die(_("pack too large for current definition of off_t"));
 300        consumed_bytes += bytes;
 301}
 302
 303static const char *open_pack_file(const char *pack_name)
 304{
 305        if (from_stdin) {
 306                input_fd = 0;
 307                if (!pack_name) {
 308                        static char tmp_file[PATH_MAX];
 309                        output_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
 310                                                "pack/tmp_pack_XXXXXX");
 311                        pack_name = xstrdup(tmp_file);
 312                } else
 313                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 314                if (output_fd < 0)
 315                        die_errno(_("unable to create '%s'"), pack_name);
 316                nothread_data.pack_fd = output_fd;
 317        } else {
 318                input_fd = open(pack_name, O_RDONLY);
 319                if (input_fd < 0)
 320                        die_errno(_("cannot open packfile '%s'"), pack_name);
 321                output_fd = -1;
 322                nothread_data.pack_fd = input_fd;
 323        }
 324        git_SHA1_Init(&input_ctx);
 325        return pack_name;
 326}
 327
 328static void parse_pack_header(void)
 329{
 330        struct pack_header *hdr = fill(sizeof(struct pack_header));
 331
 332        /* Header consistency check */
 333        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 334                die(_("pack signature mismatch"));
 335        if (!pack_version_ok(hdr->hdr_version))
 336                die(_("pack version %"PRIu32" unsupported"),
 337                        ntohl(hdr->hdr_version));
 338
 339        nr_objects = ntohl(hdr->hdr_entries);
 340        use(sizeof(struct pack_header));
 341}
 342
 343static NORETURN void bad_object(unsigned long offset, const char *format,
 344                       ...) __attribute__((format (printf, 2, 3)));
 345
 346static NORETURN void bad_object(unsigned long offset, const char *format, ...)
 347{
 348        va_list params;
 349        char buf[1024];
 350
 351        va_start(params, format);
 352        vsnprintf(buf, sizeof(buf), format, params);
 353        va_end(params);
 354        die(_("pack has bad object at offset %lu: %s"), offset, buf);
 355}
 356
 357static inline struct thread_local *get_thread_data(void)
 358{
 359#ifndef NO_PTHREADS
 360        if (threads_active)
 361                return pthread_getspecific(key);
 362        assert(!threads_active &&
 363               "This should only be reached when all threads are gone");
 364#endif
 365        return &nothread_data;
 366}
 367
 368#ifndef NO_PTHREADS
 369static void set_thread_data(struct thread_local *data)
 370{
 371        if (threads_active)
 372                pthread_setspecific(key, data);
 373}
 374#endif
 375
 376static struct base_data *alloc_base_data(void)
 377{
 378        struct base_data *base = xcalloc(1, sizeof(struct base_data));
 379        base->ref_last = -1;
 380        base->ofs_last = -1;
 381        return base;
 382}
 383
 384static void free_base_data(struct base_data *c)
 385{
 386        if (c->data) {
 387                free(c->data);
 388                c->data = NULL;
 389                get_thread_data()->base_cache_used -= c->size;
 390        }
 391}
 392
 393static void prune_base_data(struct base_data *retain)
 394{
 395        struct base_data *b;
 396        struct thread_local *data = get_thread_data();
 397        for (b = data->base_cache;
 398             data->base_cache_used > delta_base_cache_limit && b;
 399             b = b->child) {
 400                if (b->data && b != retain)
 401                        free_base_data(b);
 402        }
 403}
 404
 405static void link_base_data(struct base_data *base, struct base_data *c)
 406{
 407        if (base)
 408                base->child = c;
 409        else
 410                get_thread_data()->base_cache = c;
 411
 412        c->base = base;
 413        c->child = NULL;
 414        if (c->data)
 415                get_thread_data()->base_cache_used += c->size;
 416        prune_base_data(c);
 417}
 418
 419static void unlink_base_data(struct base_data *c)
 420{
 421        struct base_data *base = c->base;
 422        if (base)
 423                base->child = NULL;
 424        else
 425                get_thread_data()->base_cache = NULL;
 426        free_base_data(c);
 427}
 428
 429static int is_delta_type(enum object_type type)
 430{
 431        return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 432}
 433
 434static void *unpack_entry_data(unsigned long offset, unsigned long size,
 435                               enum object_type type, unsigned char *sha1)
 436{
 437        static char fixed_buf[8192];
 438        int status;
 439        git_zstream stream;
 440        void *buf;
 441        git_SHA_CTX c;
 442        char hdr[32];
 443        int hdrlen;
 444
 445        if (!is_delta_type(type)) {
 446                hdrlen = sprintf(hdr, "%s %lu", typename(type), size) + 1;
 447                git_SHA1_Init(&c);
 448                git_SHA1_Update(&c, hdr, hdrlen);
 449        } else
 450                sha1 = NULL;
 451        if (type == OBJ_BLOB && size > big_file_threshold)
 452                buf = fixed_buf;
 453        else
 454                buf = xmallocz(size);
 455
 456        memset(&stream, 0, sizeof(stream));
 457        git_inflate_init(&stream);
 458        stream.next_out = buf;
 459        stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 460
 461        do {
 462                unsigned char *last_out = stream.next_out;
 463                stream.next_in = fill(1);
 464                stream.avail_in = input_len;
 465                status = git_inflate(&stream, 0);
 466                use(input_len - stream.avail_in);
 467                if (sha1)
 468                        git_SHA1_Update(&c, last_out, stream.next_out - last_out);
 469                if (buf == fixed_buf) {
 470                        stream.next_out = buf;
 471                        stream.avail_out = sizeof(fixed_buf);
 472                }
 473        } while (status == Z_OK);
 474        if (stream.total_out != size || status != Z_STREAM_END)
 475                bad_object(offset, _("inflate returned %d"), status);
 476        git_inflate_end(&stream);
 477        if (sha1)
 478                git_SHA1_Final(sha1, &c);
 479        return buf == fixed_buf ? NULL : buf;
 480}
 481
 482static void *unpack_raw_entry(struct object_entry *obj,
 483                              union delta_base *delta_base,
 484                              unsigned char *sha1)
 485{
 486        unsigned char *p;
 487        unsigned long size, c;
 488        off_t base_offset;
 489        unsigned shift;
 490        void *data;
 491
 492        obj->idx.offset = consumed_bytes;
 493        input_crc32 = crc32(0, NULL, 0);
 494
 495        p = fill(1);
 496        c = *p;
 497        use(1);
 498        obj->type = (c >> 4) & 7;
 499        size = (c & 15);
 500        shift = 4;
 501        while (c & 0x80) {
 502                p = fill(1);
 503                c = *p;
 504                use(1);
 505                size += (c & 0x7f) << shift;
 506                shift += 7;
 507        }
 508        obj->size = size;
 509
 510        switch (obj->type) {
 511        case OBJ_REF_DELTA:
 512                hashcpy(delta_base->sha1, fill(20));
 513                use(20);
 514                break;
 515        case OBJ_OFS_DELTA:
 516                memset(delta_base, 0, sizeof(*delta_base));
 517                p = fill(1);
 518                c = *p;
 519                use(1);
 520                base_offset = c & 127;
 521                while (c & 128) {
 522                        base_offset += 1;
 523                        if (!base_offset || MSB(base_offset, 7))
 524                                bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 525                        p = fill(1);
 526                        c = *p;
 527                        use(1);
 528                        base_offset = (base_offset << 7) + (c & 127);
 529                }
 530                delta_base->offset = obj->idx.offset - base_offset;
 531                if (delta_base->offset <= 0 || delta_base->offset >= obj->idx.offset)
 532                        bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 533                break;
 534        case OBJ_COMMIT:
 535        case OBJ_TREE:
 536        case OBJ_BLOB:
 537        case OBJ_TAG:
 538                break;
 539        default:
 540                bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 541        }
 542        obj->hdr_size = consumed_bytes - obj->idx.offset;
 543
 544        data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, sha1);
 545        obj->idx.crc32 = input_crc32;
 546        return data;
 547}
 548
 549static void *unpack_data(struct object_entry *obj,
 550                         int (*consume)(const unsigned char *, unsigned long, void *),
 551                         void *cb_data)
 552{
 553        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 554        unsigned long len = obj[1].idx.offset - from;
 555        unsigned char *data, *inbuf;
 556        git_zstream stream;
 557        int status;
 558
 559        data = xmallocz(consume ? 64*1024 : obj->size);
 560        inbuf = xmalloc((len < 64*1024) ? len : 64*1024);
 561
 562        memset(&stream, 0, sizeof(stream));
 563        git_inflate_init(&stream);
 564        stream.next_out = data;
 565        stream.avail_out = consume ? 64*1024 : obj->size;
 566
 567        do {
 568                ssize_t n = (len < 64*1024) ? len : 64*1024;
 569                n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 570                if (n < 0)
 571                        die_errno(_("cannot pread pack file"));
 572                if (!n)
 573                        die(Q_("premature end of pack file, %lu byte missing",
 574                               "premature end of pack file, %lu bytes missing",
 575                               len),
 576                            len);
 577                from += n;
 578                len -= n;
 579                stream.next_in = inbuf;
 580                stream.avail_in = n;
 581                if (!consume)
 582                        status = git_inflate(&stream, 0);
 583                else {
 584                        do {
 585                                status = git_inflate(&stream, 0);
 586                                if (consume(data, stream.next_out - data, cb_data)) {
 587                                        free(inbuf);
 588                                        free(data);
 589                                        return NULL;
 590                                }
 591                                stream.next_out = data;
 592                                stream.avail_out = 64*1024;
 593                        } while (status == Z_OK && stream.avail_in);
 594                }
 595        } while (len && status == Z_OK && !stream.avail_in);
 596
 597        /* This has been inflated OK when first encountered, so... */
 598        if (status != Z_STREAM_END || stream.total_out != obj->size)
 599                die(_("serious inflate inconsistency"));
 600
 601        git_inflate_end(&stream);
 602        free(inbuf);
 603        if (consume) {
 604                free(data);
 605                data = NULL;
 606        }
 607        return data;
 608}
 609
 610static void *get_data_from_pack(struct object_entry *obj)
 611{
 612        return unpack_data(obj, NULL, NULL);
 613}
 614
 615static int compare_delta_bases(const union delta_base *base1,
 616                               const union delta_base *base2,
 617                               enum object_type type1,
 618                               enum object_type type2)
 619{
 620        int cmp = type1 - type2;
 621        if (cmp)
 622                return cmp;
 623        return memcmp(base1, base2, UNION_BASE_SZ);
 624}
 625
 626static int find_delta(const union delta_base *base, enum object_type type)
 627{
 628        int first = 0, last = nr_deltas;
 629
 630        while (first < last) {
 631                int next = (first + last) / 2;
 632                struct delta_entry *delta = &deltas[next];
 633                int cmp;
 634
 635                cmp = compare_delta_bases(base, &delta->base,
 636                                          type, objects[delta->obj_no].type);
 637                if (!cmp)
 638                        return next;
 639                if (cmp < 0) {
 640                        last = next;
 641                        continue;
 642                }
 643                first = next+1;
 644        }
 645        return -first-1;
 646}
 647
 648static void find_delta_children(const union delta_base *base,
 649                                int *first_index, int *last_index,
 650                                enum object_type type)
 651{
 652        int first = find_delta(base, type);
 653        int last = first;
 654        int end = nr_deltas - 1;
 655
 656        if (first < 0) {
 657                *first_index = 0;
 658                *last_index = -1;
 659                return;
 660        }
 661        while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
 662                --first;
 663        while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
 664                ++last;
 665        *first_index = first;
 666        *last_index = last;
 667}
 668
 669struct compare_data {
 670        struct object_entry *entry;
 671        struct git_istream *st;
 672        unsigned char *buf;
 673        unsigned long buf_size;
 674};
 675
 676static int compare_objects(const unsigned char *buf, unsigned long size,
 677                           void *cb_data)
 678{
 679        struct compare_data *data = cb_data;
 680
 681        if (data->buf_size < size) {
 682                free(data->buf);
 683                data->buf = xmalloc(size);
 684                data->buf_size = size;
 685        }
 686
 687        while (size) {
 688                ssize_t len = read_istream(data->st, data->buf, size);
 689                if (len == 0)
 690                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 691                            sha1_to_hex(data->entry->idx.sha1));
 692                if (len < 0)
 693                        die(_("unable to read %s"),
 694                            sha1_to_hex(data->entry->idx.sha1));
 695                if (memcmp(buf, data->buf, len))
 696                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 697                            sha1_to_hex(data->entry->idx.sha1));
 698                size -= len;
 699                buf += len;
 700        }
 701        return 0;
 702}
 703
 704static int check_collison(struct object_entry *entry)
 705{
 706        struct compare_data data;
 707        enum object_type type;
 708        unsigned long size;
 709
 710        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 711                return -1;
 712
 713        memset(&data, 0, sizeof(data));
 714        data.entry = entry;
 715        data.st = open_istream(entry->idx.sha1, &type, &size, NULL);
 716        if (!data.st)
 717                return -1;
 718        if (size != entry->size || type != entry->type)
 719                die(_("SHA1 COLLISION FOUND WITH %s !"),
 720                    sha1_to_hex(entry->idx.sha1));
 721        unpack_data(entry, compare_objects, &data);
 722        close_istream(data.st);
 723        free(data.buf);
 724        return 0;
 725}
 726
 727static void sha1_object(const void *data, struct object_entry *obj_entry,
 728                        unsigned long size, enum object_type type,
 729                        const unsigned char *sha1)
 730{
 731        void *new_data = NULL;
 732        int collision_test_needed;
 733
 734        assert(data || obj_entry);
 735
 736        read_lock();
 737        collision_test_needed = has_sha1_file(sha1);
 738        read_unlock();
 739
 740        if (collision_test_needed && !data) {
 741                read_lock();
 742                if (!check_collison(obj_entry))
 743                        collision_test_needed = 0;
 744                read_unlock();
 745        }
 746        if (collision_test_needed) {
 747                void *has_data;
 748                enum object_type has_type;
 749                unsigned long has_size;
 750                read_lock();
 751                has_type = sha1_object_info(sha1, &has_size);
 752                if (has_type != type || has_size != size)
 753                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 754                has_data = read_sha1_file(sha1, &has_type, &has_size);
 755                read_unlock();
 756                if (!data)
 757                        data = new_data = get_data_from_pack(obj_entry);
 758                if (!has_data)
 759                        die(_("cannot read existing object %s"), sha1_to_hex(sha1));
 760                if (size != has_size || type != has_type ||
 761                    memcmp(data, has_data, size) != 0)
 762                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 763                free(has_data);
 764        }
 765
 766        if (strict) {
 767                read_lock();
 768                if (type == OBJ_BLOB) {
 769                        struct blob *blob = lookup_blob(sha1);
 770                        if (blob)
 771                                blob->object.flags |= FLAG_CHECKED;
 772                        else
 773                                die(_("invalid blob object %s"), sha1_to_hex(sha1));
 774                } else {
 775                        struct object *obj;
 776                        int eaten;
 777                        void *buf = (void *) data;
 778
 779                        assert(data && "data can only be NULL for large _blobs_");
 780
 781                        /*
 782                         * we do not need to free the memory here, as the
 783                         * buf is deleted by the caller.
 784                         */
 785                        obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 786                        if (!obj)
 787                                die(_("invalid %s"), typename(type));
 788                        if (do_fsck_object &&
 789                            fsck_object(obj, buf, size, 1,
 790                                    fsck_error_function))
 791                                die(_("Error in object"));
 792                        if (fsck_walk(obj, mark_link, NULL))
 793                                die(_("Not all child objects of %s are reachable"), sha1_to_hex(obj->sha1));
 794
 795                        if (obj->type == OBJ_TREE) {
 796                                struct tree *item = (struct tree *) obj;
 797                                item->buffer = NULL;
 798                                obj->parsed = 0;
 799                        }
 800                        if (obj->type == OBJ_COMMIT) {
 801                                struct commit *commit = (struct commit *) obj;
 802                                if (detach_commit_buffer(commit, NULL) != data)
 803                                        die("BUG: parse_object_buffer transmogrified our buffer");
 804                        }
 805                        obj->flags |= FLAG_CHECKED;
 806                }
 807                read_unlock();
 808        }
 809
 810        free(new_data);
 811}
 812
 813/*
 814 * This function is part of find_unresolved_deltas(). There are two
 815 * walkers going in the opposite ways.
 816 *
 817 * The first one in find_unresolved_deltas() traverses down from
 818 * parent node to children, deflating nodes along the way. However,
 819 * memory for deflated nodes is limited by delta_base_cache_limit, so
 820 * at some point parent node's deflated content may be freed.
 821 *
 822 * The second walker is this function, which goes from current node up
 823 * to top parent if necessary to deflate the node. In normal
 824 * situation, its parent node would be already deflated, so it just
 825 * needs to apply delta.
 826 *
 827 * In the worst case scenario, parent node is no longer deflated because
 828 * we're running out of delta_base_cache_limit; we need to re-deflate
 829 * parents, possibly up to the top base.
 830 *
 831 * All deflated objects here are subject to be freed if we exceed
 832 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 833 * just need to make sure the last node is not freed.
 834 */
 835static void *get_base_data(struct base_data *c)
 836{
 837        if (!c->data) {
 838                struct object_entry *obj = c->obj;
 839                struct base_data **delta = NULL;
 840                int delta_nr = 0, delta_alloc = 0;
 841
 842                while (is_delta_type(c->obj->type) && !c->data) {
 843                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 844                        delta[delta_nr++] = c;
 845                        c = c->base;
 846                }
 847                if (!delta_nr) {
 848                        c->data = get_data_from_pack(obj);
 849                        c->size = obj->size;
 850                        get_thread_data()->base_cache_used += c->size;
 851                        prune_base_data(c);
 852                }
 853                for (; delta_nr > 0; delta_nr--) {
 854                        void *base, *raw;
 855                        c = delta[delta_nr - 1];
 856                        obj = c->obj;
 857                        base = get_base_data(c->base);
 858                        raw = get_data_from_pack(obj);
 859                        c->data = patch_delta(
 860                                base, c->base->size,
 861                                raw, obj->size,
 862                                &c->size);
 863                        free(raw);
 864                        if (!c->data)
 865                                bad_object(obj->idx.offset, _("failed to apply delta"));
 866                        get_thread_data()->base_cache_used += c->size;
 867                        prune_base_data(c);
 868                }
 869                free(delta);
 870        }
 871        return c->data;
 872}
 873
 874static void resolve_delta(struct object_entry *delta_obj,
 875                          struct base_data *base, struct base_data *result)
 876{
 877        void *base_data, *delta_data;
 878
 879        if (show_stat) {
 880                int i = delta_obj - objects;
 881                int j = base->obj - objects;
 882                obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 883                deepest_delta_lock();
 884                if (deepest_delta < obj_stat[i].delta_depth)
 885                        deepest_delta = obj_stat[i].delta_depth;
 886                deepest_delta_unlock();
 887                obj_stat[i].base_object_no = j;
 888        }
 889        delta_data = get_data_from_pack(delta_obj);
 890        base_data = get_base_data(base);
 891        result->obj = delta_obj;
 892        result->data = patch_delta(base_data, base->size,
 893                                   delta_data, delta_obj->size, &result->size);
 894        free(delta_data);
 895        if (!result->data)
 896                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 897        hash_sha1_file(result->data, result->size,
 898                       typename(delta_obj->real_type), delta_obj->idx.sha1);
 899        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 900                    delta_obj->idx.sha1);
 901        counter_lock();
 902        nr_resolved_deltas++;
 903        counter_unlock();
 904}
 905
 906/*
 907 * Standard boolean compare-and-swap: atomically check whether "*type" is
 908 * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 909 * and return false.
 910 */
 911static int compare_and_swap_type(signed char *type,
 912                                 enum object_type want,
 913                                 enum object_type set)
 914{
 915        enum object_type old;
 916
 917        type_cas_lock();
 918        old = *type;
 919        if (old == want)
 920                *type = set;
 921        type_cas_unlock();
 922
 923        return old == want;
 924}
 925
 926static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 927                                                  struct base_data *prev_base)
 928{
 929        if (base->ref_last == -1 && base->ofs_last == -1) {
 930                union delta_base base_spec;
 931
 932                hashcpy(base_spec.sha1, base->obj->idx.sha1);
 933                find_delta_children(&base_spec,
 934                                    &base->ref_first, &base->ref_last, OBJ_REF_DELTA);
 935
 936                memset(&base_spec, 0, sizeof(base_spec));
 937                base_spec.offset = base->obj->idx.offset;
 938                find_delta_children(&base_spec,
 939                                    &base->ofs_first, &base->ofs_last, OBJ_OFS_DELTA);
 940
 941                if (base->ref_last == -1 && base->ofs_last == -1) {
 942                        free(base->data);
 943                        return NULL;
 944                }
 945
 946                link_base_data(prev_base, base);
 947        }
 948
 949        if (base->ref_first <= base->ref_last) {
 950                struct object_entry *child = objects + deltas[base->ref_first].obj_no;
 951                struct base_data *result = alloc_base_data();
 952
 953                if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
 954                                           base->obj->real_type))
 955                        die("BUG: child->real_type != OBJ_REF_DELTA");
 956
 957                resolve_delta(child, base, result);
 958                if (base->ref_first == base->ref_last && base->ofs_last == -1)
 959                        free_base_data(base);
 960
 961                base->ref_first++;
 962                return result;
 963        }
 964
 965        if (base->ofs_first <= base->ofs_last) {
 966                struct object_entry *child = objects + deltas[base->ofs_first].obj_no;
 967                struct base_data *result = alloc_base_data();
 968
 969                assert(child->real_type == OBJ_OFS_DELTA);
 970                child->real_type = base->obj->real_type;
 971                resolve_delta(child, base, result);
 972                if (base->ofs_first == base->ofs_last)
 973                        free_base_data(base);
 974
 975                base->ofs_first++;
 976                return result;
 977        }
 978
 979        unlink_base_data(base);
 980        return NULL;
 981}
 982
 983static void find_unresolved_deltas(struct base_data *base)
 984{
 985        struct base_data *new_base, *prev_base = NULL;
 986        for (;;) {
 987                new_base = find_unresolved_deltas_1(base, prev_base);
 988
 989                if (new_base) {
 990                        prev_base = base;
 991                        base = new_base;
 992                } else {
 993                        free(base);
 994                        base = prev_base;
 995                        if (!base)
 996                                return;
 997                        prev_base = base->base;
 998                }
 999        }
1000}
1001
1002static int compare_delta_entry(const void *a, const void *b)
1003{
1004        const struct delta_entry *delta_a = a;
1005        const struct delta_entry *delta_b = b;
1006
1007        /* group by type (ref vs ofs) and then by value (sha-1 or offset) */
1008        return compare_delta_bases(&delta_a->base, &delta_b->base,
1009                                   objects[delta_a->obj_no].type,
1010                                   objects[delta_b->obj_no].type);
1011}
1012
1013static void resolve_base(struct object_entry *obj)
1014{
1015        struct base_data *base_obj = alloc_base_data();
1016        base_obj->obj = obj;
1017        base_obj->data = NULL;
1018        find_unresolved_deltas(base_obj);
1019}
1020
1021#ifndef NO_PTHREADS
1022static void *threaded_second_pass(void *data)
1023{
1024        set_thread_data(data);
1025        for (;;) {
1026                int i;
1027                counter_lock();
1028                display_progress(progress, nr_resolved_deltas);
1029                counter_unlock();
1030                work_lock();
1031                while (nr_dispatched < nr_objects &&
1032                       is_delta_type(objects[nr_dispatched].type))
1033                        nr_dispatched++;
1034                if (nr_dispatched >= nr_objects) {
1035                        work_unlock();
1036                        break;
1037                }
1038                i = nr_dispatched++;
1039                work_unlock();
1040
1041                resolve_base(&objects[i]);
1042        }
1043        return NULL;
1044}
1045#endif
1046
1047/*
1048 * First pass:
1049 * - find locations of all objects;
1050 * - calculate SHA1 of all non-delta objects;
1051 * - remember base (SHA1 or offset) for all deltas.
1052 */
1053static void parse_pack_objects(unsigned char *sha1)
1054{
1055        int i, nr_delays = 0;
1056        struct delta_entry *delta = deltas;
1057        struct stat st;
1058
1059        if (verbose)
1060                progress = start_progress(
1061                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1062                                nr_objects);
1063        for (i = 0; i < nr_objects; i++) {
1064                struct object_entry *obj = &objects[i];
1065                void *data = unpack_raw_entry(obj, &delta->base, obj->idx.sha1);
1066                obj->real_type = obj->type;
1067                if (is_delta_type(obj->type)) {
1068                        nr_deltas++;
1069                        delta->obj_no = i;
1070                        delta++;
1071                } else if (!data) {
1072                        /* large blobs, check later */
1073                        obj->real_type = OBJ_BAD;
1074                        nr_delays++;
1075                } else
1076                        sha1_object(data, NULL, obj->size, obj->type, obj->idx.sha1);
1077                free(data);
1078                display_progress(progress, i+1);
1079        }
1080        objects[i].idx.offset = consumed_bytes;
1081        stop_progress(&progress);
1082
1083        /* Check pack integrity */
1084        flush();
1085        git_SHA1_Final(sha1, &input_ctx);
1086        if (hashcmp(fill(20), sha1))
1087                die(_("pack is corrupted (SHA1 mismatch)"));
1088        use(20);
1089
1090        /* If input_fd is a file, we should have reached its end now. */
1091        if (fstat(input_fd, &st))
1092                die_errno(_("cannot fstat packfile"));
1093        if (S_ISREG(st.st_mode) &&
1094                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1095                die(_("pack has junk at the end"));
1096
1097        for (i = 0; i < nr_objects; i++) {
1098                struct object_entry *obj = &objects[i];
1099                if (obj->real_type != OBJ_BAD)
1100                        continue;
1101                obj->real_type = obj->type;
1102                sha1_object(NULL, obj, obj->size, obj->type, obj->idx.sha1);
1103                nr_delays--;
1104        }
1105        if (nr_delays)
1106                die(_("confusion beyond insanity in parse_pack_objects()"));
1107}
1108
1109/*
1110 * Second pass:
1111 * - for all non-delta objects, look if it is used as a base for
1112 *   deltas;
1113 * - if used as a base, uncompress the object and apply all deltas,
1114 *   recursively checking if the resulting object is used as a base
1115 *   for some more deltas.
1116 */
1117static void resolve_deltas(void)
1118{
1119        int i;
1120
1121        if (!nr_deltas)
1122                return;
1123
1124        /* Sort deltas by base SHA1/offset for fast searching */
1125        qsort(deltas, nr_deltas, sizeof(struct delta_entry),
1126              compare_delta_entry);
1127
1128        if (verbose)
1129                progress = start_progress(_("Resolving deltas"), nr_deltas);
1130
1131#ifndef NO_PTHREADS
1132        nr_dispatched = 0;
1133        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1134                init_thread();
1135                for (i = 0; i < nr_threads; i++) {
1136                        int ret = pthread_create(&thread_data[i].thread, NULL,
1137                                                 threaded_second_pass, thread_data + i);
1138                        if (ret)
1139                                die(_("unable to create thread: %s"),
1140                                    strerror(ret));
1141                }
1142                for (i = 0; i < nr_threads; i++)
1143                        pthread_join(thread_data[i].thread, NULL);
1144                cleanup_thread();
1145                return;
1146        }
1147#endif
1148
1149        for (i = 0; i < nr_objects; i++) {
1150                struct object_entry *obj = &objects[i];
1151
1152                if (is_delta_type(obj->type))
1153                        continue;
1154                resolve_base(obj);
1155                display_progress(progress, nr_resolved_deltas);
1156        }
1157}
1158
1159/*
1160 * Third pass:
1161 * - append objects to convert thin pack to full pack if required
1162 * - write the final 20-byte SHA-1
1163 */
1164static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved);
1165static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
1166{
1167        if (nr_deltas == nr_resolved_deltas) {
1168                stop_progress(&progress);
1169                /* Flush remaining pack final 20-byte SHA1. */
1170                flush();
1171                return;
1172        }
1173
1174        if (fix_thin_pack) {
1175                struct sha1file *f;
1176                unsigned char read_sha1[20], tail_sha1[20];
1177                struct strbuf msg = STRBUF_INIT;
1178                int nr_unresolved = nr_deltas - nr_resolved_deltas;
1179                int nr_objects_initial = nr_objects;
1180                if (nr_unresolved <= 0)
1181                        die(_("confusion beyond insanity"));
1182                REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1183                memset(objects + nr_objects + 1, 0,
1184                       nr_unresolved * sizeof(*objects));
1185                f = sha1fd(output_fd, curr_pack);
1186                fix_unresolved_deltas(f, nr_unresolved);
1187                strbuf_addf(&msg, _("completed with %d local objects"),
1188                            nr_objects - nr_objects_initial);
1189                stop_progress_msg(&progress, msg.buf);
1190                strbuf_release(&msg);
1191                sha1close(f, tail_sha1, 0);
1192                hashcpy(read_sha1, pack_sha1);
1193                fixup_pack_header_footer(output_fd, pack_sha1,
1194                                         curr_pack, nr_objects,
1195                                         read_sha1, consumed_bytes-20);
1196                if (hashcmp(read_sha1, tail_sha1) != 0)
1197                        die(_("Unexpected tail checksum for %s "
1198                              "(disk corruption?)"), curr_pack);
1199        }
1200        if (nr_deltas != nr_resolved_deltas)
1201                die(Q_("pack has %d unresolved delta",
1202                       "pack has %d unresolved deltas",
1203                       nr_deltas - nr_resolved_deltas),
1204                    nr_deltas - nr_resolved_deltas);
1205}
1206
1207static int write_compressed(struct sha1file *f, void *in, unsigned int size)
1208{
1209        git_zstream stream;
1210        int status;
1211        unsigned char outbuf[4096];
1212
1213        memset(&stream, 0, sizeof(stream));
1214        git_deflate_init(&stream, zlib_compression_level);
1215        stream.next_in = in;
1216        stream.avail_in = size;
1217
1218        do {
1219                stream.next_out = outbuf;
1220                stream.avail_out = sizeof(outbuf);
1221                status = git_deflate(&stream, Z_FINISH);
1222                sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
1223        } while (status == Z_OK);
1224
1225        if (status != Z_STREAM_END)
1226                die(_("unable to deflate appended object (%d)"), status);
1227        size = stream.total_out;
1228        git_deflate_end(&stream);
1229        return size;
1230}
1231
1232static struct object_entry *append_obj_to_pack(struct sha1file *f,
1233                               const unsigned char *sha1, void *buf,
1234                               unsigned long size, enum object_type type)
1235{
1236        struct object_entry *obj = &objects[nr_objects++];
1237        unsigned char header[10];
1238        unsigned long s = size;
1239        int n = 0;
1240        unsigned char c = (type << 4) | (s & 15);
1241        s >>= 4;
1242        while (s) {
1243                header[n++] = c | 0x80;
1244                c = s & 0x7f;
1245                s >>= 7;
1246        }
1247        header[n++] = c;
1248        crc32_begin(f);
1249        sha1write(f, header, n);
1250        obj[0].size = size;
1251        obj[0].hdr_size = n;
1252        obj[0].type = type;
1253        obj[0].real_type = type;
1254        obj[1].idx.offset = obj[0].idx.offset + n;
1255        obj[1].idx.offset += write_compressed(f, buf, size);
1256        obj[0].idx.crc32 = crc32_end(f);
1257        sha1flush(f);
1258        hashcpy(obj->idx.sha1, sha1);
1259        return obj;
1260}
1261
1262static int delta_pos_compare(const void *_a, const void *_b)
1263{
1264        struct delta_entry *a = *(struct delta_entry **)_a;
1265        struct delta_entry *b = *(struct delta_entry **)_b;
1266        return a->obj_no - b->obj_no;
1267}
1268
1269static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
1270{
1271        struct delta_entry **sorted_by_pos;
1272        int i, n = 0;
1273
1274        /*
1275         * Since many unresolved deltas may well be themselves base objects
1276         * for more unresolved deltas, we really want to include the
1277         * smallest number of base objects that would cover as much delta
1278         * as possible by picking the
1279         * trunc deltas first, allowing for other deltas to resolve without
1280         * additional base objects.  Since most base objects are to be found
1281         * before deltas depending on them, a good heuristic is to start
1282         * resolving deltas in the same order as their position in the pack.
1283         */
1284        sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
1285        for (i = 0; i < nr_deltas; i++) {
1286                if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
1287                        continue;
1288                sorted_by_pos[n++] = &deltas[i];
1289        }
1290        qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
1291
1292        for (i = 0; i < n; i++) {
1293                struct delta_entry *d = sorted_by_pos[i];
1294                enum object_type type;
1295                struct base_data *base_obj = alloc_base_data();
1296
1297                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1298                        continue;
1299                base_obj->data = read_sha1_file(d->base.sha1, &type, &base_obj->size);
1300                if (!base_obj->data)
1301                        continue;
1302
1303                if (check_sha1_signature(d->base.sha1, base_obj->data,
1304                                base_obj->size, typename(type)))
1305                        die(_("local object %s is corrupt"), sha1_to_hex(d->base.sha1));
1306                base_obj->obj = append_obj_to_pack(f, d->base.sha1,
1307                                        base_obj->data, base_obj->size, type);
1308                find_unresolved_deltas(base_obj);
1309                display_progress(progress, nr_resolved_deltas);
1310        }
1311        free(sorted_by_pos);
1312}
1313
1314static void final(const char *final_pack_name, const char *curr_pack_name,
1315                  const char *final_index_name, const char *curr_index_name,
1316                  const char *keep_name, const char *keep_msg,
1317                  unsigned char *sha1)
1318{
1319        const char *report = "pack";
1320        char name[PATH_MAX];
1321        int err;
1322
1323        if (!from_stdin) {
1324                close(input_fd);
1325        } else {
1326                fsync_or_die(output_fd, curr_pack_name);
1327                err = close(output_fd);
1328                if (err)
1329                        die_errno(_("error while closing pack file"));
1330        }
1331
1332        if (keep_msg) {
1333                int keep_fd, keep_msg_len = strlen(keep_msg);
1334
1335                if (!keep_name)
1336                        keep_fd = odb_pack_keep(name, sizeof(name), sha1);
1337                else
1338                        keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
1339
1340                if (keep_fd < 0) {
1341                        if (errno != EEXIST)
1342                                die_errno(_("cannot write keep file '%s'"),
1343                                          keep_name ? keep_name : name);
1344                } else {
1345                        if (keep_msg_len > 0) {
1346                                write_or_die(keep_fd, keep_msg, keep_msg_len);
1347                                write_or_die(keep_fd, "\n", 1);
1348                        }
1349                        if (close(keep_fd) != 0)
1350                                die_errno(_("cannot close written keep file '%s'"),
1351                                          keep_name ? keep_name : name);
1352                        report = "keep";
1353                }
1354        }
1355
1356        if (final_pack_name != curr_pack_name) {
1357                if (!final_pack_name) {
1358                        snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
1359                                 get_object_directory(), sha1_to_hex(sha1));
1360                        final_pack_name = name;
1361                }
1362                if (move_temp_to_file(curr_pack_name, final_pack_name))
1363                        die(_("cannot store pack file"));
1364        } else if (from_stdin)
1365                chmod(final_pack_name, 0444);
1366
1367        if (final_index_name != curr_index_name) {
1368                if (!final_index_name) {
1369                        snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
1370                                 get_object_directory(), sha1_to_hex(sha1));
1371                        final_index_name = name;
1372                }
1373                if (move_temp_to_file(curr_index_name, final_index_name))
1374                        die(_("cannot store index file"));
1375        } else
1376                chmod(final_index_name, 0444);
1377
1378        if (!from_stdin) {
1379                printf("%s\n", sha1_to_hex(sha1));
1380        } else {
1381                char buf[48];
1382                int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
1383                                   report, sha1_to_hex(sha1));
1384                write_or_die(1, buf, len);
1385
1386                /*
1387                 * Let's just mimic git-unpack-objects here and write
1388                 * the last part of the input buffer to stdout.
1389                 */
1390                while (input_len) {
1391                        err = xwrite(1, input_buffer + input_offset, input_len);
1392                        if (err <= 0)
1393                                break;
1394                        input_len -= err;
1395                        input_offset += err;
1396                }
1397        }
1398}
1399
1400static int git_index_pack_config(const char *k, const char *v, void *cb)
1401{
1402        struct pack_idx_option *opts = cb;
1403
1404        if (!strcmp(k, "pack.indexversion")) {
1405                opts->version = git_config_int(k, v);
1406                if (opts->version > 2)
1407                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1408                return 0;
1409        }
1410        if (!strcmp(k, "pack.threads")) {
1411                nr_threads = git_config_int(k, v);
1412                if (nr_threads < 0)
1413                        die(_("invalid number of threads specified (%d)"),
1414                            nr_threads);
1415#ifdef NO_PTHREADS
1416                if (nr_threads != 1)
1417                        warning(_("no threads support, ignoring %s"), k);
1418                nr_threads = 1;
1419#endif
1420                return 0;
1421        }
1422        return git_default_config(k, v, cb);
1423}
1424
1425static int cmp_uint32(const void *a_, const void *b_)
1426{
1427        uint32_t a = *((uint32_t *)a_);
1428        uint32_t b = *((uint32_t *)b_);
1429
1430        return (a < b) ? -1 : (a != b);
1431}
1432
1433static void read_v2_anomalous_offsets(struct packed_git *p,
1434                                      struct pack_idx_option *opts)
1435{
1436        const uint32_t *idx1, *idx2;
1437        uint32_t i;
1438
1439        /* The address of the 4-byte offset table */
1440        idx1 = (((const uint32_t *)p->index_data)
1441                + 2 /* 8-byte header */
1442                + 256 /* fan out */
1443                + 5 * p->num_objects /* 20-byte SHA-1 table */
1444                + p->num_objects /* CRC32 table */
1445                );
1446
1447        /* The address of the 8-byte offset table */
1448        idx2 = idx1 + p->num_objects;
1449
1450        for (i = 0; i < p->num_objects; i++) {
1451                uint32_t off = ntohl(idx1[i]);
1452                if (!(off & 0x80000000))
1453                        continue;
1454                off = off & 0x7fffffff;
1455                if (idx2[off * 2])
1456                        continue;
1457                /*
1458                 * The real offset is ntohl(idx2[off * 2]) in high 4
1459                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1460                 * octets.  But idx2[off * 2] is Zero!!!
1461                 */
1462                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1463                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1464        }
1465
1466        if (1 < opts->anomaly_nr)
1467                qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
1468}
1469
1470static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1471{
1472        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1473
1474        if (!p)
1475                die(_("Cannot open existing pack file '%s'"), pack_name);
1476        if (open_pack_index(p))
1477                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1478
1479        /* Read the attributes from the existing idx file */
1480        opts->version = p->index_version;
1481
1482        if (opts->version == 2)
1483                read_v2_anomalous_offsets(p, opts);
1484
1485        /*
1486         * Get rid of the idx file as we do not need it anymore.
1487         * NEEDSWORK: extract this bit from free_pack_by_name() in
1488         * sha1_file.c, perhaps?  It shouldn't matter very much as we
1489         * know we haven't installed this pack (hence we never have
1490         * read anything from it).
1491         */
1492        close_pack_index(p);
1493        free(p);
1494}
1495
1496static void show_pack_info(int stat_only)
1497{
1498        int i, baseobjects = nr_objects - nr_deltas;
1499        unsigned long *chain_histogram = NULL;
1500
1501        if (deepest_delta)
1502                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1503
1504        for (i = 0; i < nr_objects; i++) {
1505                struct object_entry *obj = &objects[i];
1506
1507                if (is_delta_type(obj->type))
1508                        chain_histogram[obj_stat[i].delta_depth - 1]++;
1509                if (stat_only)
1510                        continue;
1511                printf("%s %-6s %lu %lu %"PRIuMAX,
1512                       sha1_to_hex(obj->idx.sha1),
1513                       typename(obj->real_type), obj->size,
1514                       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1515                       (uintmax_t)obj->idx.offset);
1516                if (is_delta_type(obj->type)) {
1517                        struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1518                        printf(" %u %s", obj_stat[i].delta_depth, sha1_to_hex(bobj->idx.sha1));
1519                }
1520                putchar('\n');
1521        }
1522
1523        if (baseobjects)
1524                printf_ln(Q_("non delta: %d object",
1525                             "non delta: %d objects",
1526                             baseobjects),
1527                          baseobjects);
1528        for (i = 0; i < deepest_delta; i++) {
1529                if (!chain_histogram[i])
1530                        continue;
1531                printf_ln(Q_("chain length = %d: %lu object",
1532                             "chain length = %d: %lu objects",
1533                             chain_histogram[i]),
1534                          i + 1,
1535                          chain_histogram[i]);
1536        }
1537}
1538
1539int cmd_index_pack(int argc, const char **argv, const char *prefix)
1540{
1541        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1542        const char *curr_index;
1543        const char *index_name = NULL, *pack_name = NULL;
1544        const char *keep_name = NULL, *keep_msg = NULL;
1545        struct strbuf index_name_buf = STRBUF_INIT,
1546                      keep_name_buf = STRBUF_INIT;
1547        struct pack_idx_entry **idx_objects;
1548        struct pack_idx_option opts;
1549        unsigned char pack_sha1[20];
1550        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1551
1552        if (argc == 2 && !strcmp(argv[1], "-h"))
1553                usage(index_pack_usage);
1554
1555        check_replace_refs = 0;
1556
1557        reset_pack_idx_option(&opts);
1558        git_config(git_index_pack_config, &opts);
1559        if (prefix && chdir(prefix))
1560                die(_("Cannot come back to cwd"));
1561
1562        for (i = 1; i < argc; i++) {
1563                const char *arg = argv[i];
1564
1565                if (*arg == '-') {
1566                        if (!strcmp(arg, "--stdin")) {
1567                                from_stdin = 1;
1568                        } else if (!strcmp(arg, "--fix-thin")) {
1569                                fix_thin_pack = 1;
1570                        } else if (!strcmp(arg, "--strict")) {
1571                                strict = 1;
1572                                do_fsck_object = 1;
1573                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1574                                strict = 1;
1575                                check_self_contained_and_connected = 1;
1576                        } else if (!strcmp(arg, "--verify")) {
1577                                verify = 1;
1578                        } else if (!strcmp(arg, "--verify-stat")) {
1579                                verify = 1;
1580                                show_stat = 1;
1581                        } else if (!strcmp(arg, "--verify-stat-only")) {
1582                                verify = 1;
1583                                show_stat = 1;
1584                                stat_only = 1;
1585                        } else if (!strcmp(arg, "--keep")) {
1586                                keep_msg = "";
1587                        } else if (starts_with(arg, "--keep=")) {
1588                                keep_msg = arg + 7;
1589                        } else if (starts_with(arg, "--threads=")) {
1590                                char *end;
1591                                nr_threads = strtoul(arg+10, &end, 0);
1592                                if (!arg[10] || *end || nr_threads < 0)
1593                                        usage(index_pack_usage);
1594#ifdef NO_PTHREADS
1595                                if (nr_threads != 1)
1596                                        warning(_("no threads support, "
1597                                                  "ignoring %s"), arg);
1598                                nr_threads = 1;
1599#endif
1600                        } else if (starts_with(arg, "--pack_header=")) {
1601                                struct pack_header *hdr;
1602                                char *c;
1603
1604                                hdr = (struct pack_header *)input_buffer;
1605                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1606                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1607                                if (*c != ',')
1608                                        die(_("bad %s"), arg);
1609                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1610                                if (*c)
1611                                        die(_("bad %s"), arg);
1612                                input_len = sizeof(*hdr);
1613                        } else if (!strcmp(arg, "-v")) {
1614                                verbose = 1;
1615                        } else if (!strcmp(arg, "-o")) {
1616                                if (index_name || (i+1) >= argc)
1617                                        usage(index_pack_usage);
1618                                index_name = argv[++i];
1619                        } else if (starts_with(arg, "--index-version=")) {
1620                                char *c;
1621                                opts.version = strtoul(arg + 16, &c, 10);
1622                                if (opts.version > 2)
1623                                        die(_("bad %s"), arg);
1624                                if (*c == ',')
1625                                        opts.off32_limit = strtoul(c+1, &c, 0);
1626                                if (*c || opts.off32_limit & 0x80000000)
1627                                        die(_("bad %s"), arg);
1628                        } else
1629                                usage(index_pack_usage);
1630                        continue;
1631                }
1632
1633                if (pack_name)
1634                        usage(index_pack_usage);
1635                pack_name = arg;
1636        }
1637
1638        if (!pack_name && !from_stdin)
1639                usage(index_pack_usage);
1640        if (fix_thin_pack && !from_stdin)
1641                die(_("--fix-thin cannot be used without --stdin"));
1642        if (!index_name && pack_name) {
1643                size_t len;
1644                if (!strip_suffix(pack_name, ".pack", &len))
1645                        die(_("packfile name '%s' does not end with '.pack'"),
1646                            pack_name);
1647                strbuf_add(&index_name_buf, pack_name, len);
1648                strbuf_addstr(&index_name_buf, ".idx");
1649                index_name = index_name_buf.buf;
1650        }
1651        if (keep_msg && !keep_name && pack_name) {
1652                size_t len;
1653                if (!strip_suffix(pack_name, ".pack", &len))
1654                        die(_("packfile name '%s' does not end with '.pack'"),
1655                            pack_name);
1656                strbuf_add(&keep_name_buf, pack_name, len);
1657                strbuf_addstr(&keep_name_buf, ".idx");
1658                keep_name = keep_name_buf.buf;
1659        }
1660        if (verify) {
1661                if (!index_name)
1662                        die(_("--verify with no packfile name given"));
1663                read_idx_option(&opts, index_name);
1664                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1665        }
1666        if (strict)
1667                opts.flags |= WRITE_IDX_STRICT;
1668
1669#ifndef NO_PTHREADS
1670        if (!nr_threads) {
1671                nr_threads = online_cpus();
1672                /* An experiment showed that more threads does not mean faster */
1673                if (nr_threads > 3)
1674                        nr_threads = 3;
1675        }
1676#endif
1677
1678        curr_pack = open_pack_file(pack_name);
1679        parse_pack_header();
1680        objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
1681        if (show_stat)
1682                obj_stat = xcalloc(nr_objects + 1, sizeof(struct object_stat));
1683        deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
1684        parse_pack_objects(pack_sha1);
1685        resolve_deltas();
1686        conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1687        free(deltas);
1688        if (strict)
1689                foreign_nr = check_objects();
1690
1691        if (show_stat)
1692                show_pack_info(stat_only);
1693
1694        idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
1695        for (i = 0; i < nr_objects; i++)
1696                idx_objects[i] = &objects[i].idx;
1697        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1698        free(idx_objects);
1699
1700        if (!verify)
1701                final(pack_name, curr_pack,
1702                      index_name, curr_index,
1703                      keep_name, keep_msg,
1704                      pack_sha1);
1705        else
1706                close(input_fd);
1707        free(objects);
1708        strbuf_release(&index_name_buf);
1709        strbuf_release(&keep_name_buf);
1710        if (pack_name == NULL)
1711                free((void *) curr_pack);
1712        if (index_name == NULL)
1713                free((void *) curr_index);
1714
1715        /*
1716         * Let the caller know this pack is not self contained
1717         */
1718        if (check_self_contained_and_connected && foreign_nr)
1719                return 1;
1720
1721        return 0;
1722}