builtin / index-pack.con commit Convert remaining callers of lookup_blob to object_id (3e93098)
   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
  31struct base_data {
  32        struct base_data *base;
  33        struct base_data *child;
  34        struct object_entry *obj;
  35        void *data;
  36        unsigned long size;
  37        int ref_first, ref_last;
  38        int ofs_first, ofs_last;
  39};
  40
  41struct thread_local {
  42#ifndef NO_PTHREADS
  43        pthread_t thread;
  44#endif
  45        struct base_data *base_cache;
  46        size_t base_cache_used;
  47        int pack_fd;
  48};
  49
  50#define FLAG_LINK (1u<<20)
  51#define FLAG_CHECKED (1u<<21)
  52
  53struct ofs_delta_entry {
  54        off_t offset;
  55        int obj_no;
  56};
  57
  58struct ref_delta_entry {
  59        unsigned char sha1[20];
  60        int obj_no;
  61};
  62
  63static struct object_entry *objects;
  64static struct object_stat *obj_stat;
  65static struct ofs_delta_entry *ofs_deltas;
  66static struct ref_delta_entry *ref_deltas;
  67static struct thread_local nothread_data;
  68static int nr_objects;
  69static int nr_ofs_deltas;
  70static int nr_ref_deltas;
  71static int ref_deltas_alloc;
  72static int nr_resolved_deltas;
  73static int nr_threads;
  74
  75static int from_stdin;
  76static int strict;
  77static int do_fsck_object;
  78static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
  79static int verbose;
  80static int show_resolving_progress;
  81static int show_stat;
  82static int check_self_contained_and_connected;
  83
  84static struct progress *progress;
  85
  86/* We always read in 4kB chunks. */
  87static unsigned char input_buffer[4096];
  88static unsigned int input_offset, input_len;
  89static off_t consumed_bytes;
  90static off_t max_input_size;
  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, struct fsck_options *options)
 199{
 200        if (!obj)
 201                return -1;
 202
 203        if (type != OBJ_ANY && obj->type != type)
 204                die(_("object type mismatch at %s"), oid_to_hex(&obj->oid));
 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->oid.hash, &size);
 223                if (type <= 0)
 224                        die(_("did not receive expected object %s"),
 225                              oid_to_hex(&obj->oid));
 226                if (type != obj->type)
 227                        die(_("object %s: expected type %s, found %s"),
 228                            oid_to_hex(&obj->oid),
 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        if (max_input_size && consumed_bytes > max_input_size)
 302                die(_("pack exceeds maximum allowed size"));
 303}
 304
 305static const char *open_pack_file(const char *pack_name)
 306{
 307        if (from_stdin) {
 308                input_fd = 0;
 309                if (!pack_name) {
 310                        struct strbuf tmp_file = STRBUF_INIT;
 311                        output_fd = odb_mkstemp(&tmp_file,
 312                                                "pack/tmp_pack_XXXXXX");
 313                        pack_name = strbuf_detach(&tmp_file, NULL);
 314                } else {
 315                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 316                        if (output_fd < 0)
 317                                die_errno(_("unable to create '%s'"), pack_name);
 318                }
 319                nothread_data.pack_fd = output_fd;
 320        } else {
 321                input_fd = open(pack_name, O_RDONLY);
 322                if (input_fd < 0)
 323                        die_errno(_("cannot open packfile '%s'"), pack_name);
 324                output_fd = -1;
 325                nothread_data.pack_fd = input_fd;
 326        }
 327        git_SHA1_Init(&input_ctx);
 328        return pack_name;
 329}
 330
 331static void parse_pack_header(void)
 332{
 333        struct pack_header *hdr = fill(sizeof(struct pack_header));
 334
 335        /* Header consistency check */
 336        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 337                die(_("pack signature mismatch"));
 338        if (!pack_version_ok(hdr->hdr_version))
 339                die(_("pack version %"PRIu32" unsupported"),
 340                        ntohl(hdr->hdr_version));
 341
 342        nr_objects = ntohl(hdr->hdr_entries);
 343        use(sizeof(struct pack_header));
 344}
 345
 346static NORETURN void bad_object(off_t offset, const char *format,
 347                       ...) __attribute__((format (printf, 2, 3)));
 348
 349static NORETURN void bad_object(off_t offset, const char *format, ...)
 350{
 351        va_list params;
 352        char buf[1024];
 353
 354        va_start(params, format);
 355        vsnprintf(buf, sizeof(buf), format, params);
 356        va_end(params);
 357        die(_("pack has bad object at offset %"PRIuMAX": %s"),
 358            (uintmax_t)offset, buf);
 359}
 360
 361static inline struct thread_local *get_thread_data(void)
 362{
 363#ifndef NO_PTHREADS
 364        if (threads_active)
 365                return pthread_getspecific(key);
 366        assert(!threads_active &&
 367               "This should only be reached when all threads are gone");
 368#endif
 369        return &nothread_data;
 370}
 371
 372#ifndef NO_PTHREADS
 373static void set_thread_data(struct thread_local *data)
 374{
 375        if (threads_active)
 376                pthread_setspecific(key, data);
 377}
 378#endif
 379
 380static struct base_data *alloc_base_data(void)
 381{
 382        struct base_data *base = xcalloc(1, sizeof(struct base_data));
 383        base->ref_last = -1;
 384        base->ofs_last = -1;
 385        return base;
 386}
 387
 388static void free_base_data(struct base_data *c)
 389{
 390        if (c->data) {
 391                free(c->data);
 392                c->data = NULL;
 393                get_thread_data()->base_cache_used -= c->size;
 394        }
 395}
 396
 397static void prune_base_data(struct base_data *retain)
 398{
 399        struct base_data *b;
 400        struct thread_local *data = get_thread_data();
 401        for (b = data->base_cache;
 402             data->base_cache_used > delta_base_cache_limit && b;
 403             b = b->child) {
 404                if (b->data && b != retain)
 405                        free_base_data(b);
 406        }
 407}
 408
 409static void link_base_data(struct base_data *base, struct base_data *c)
 410{
 411        if (base)
 412                base->child = c;
 413        else
 414                get_thread_data()->base_cache = c;
 415
 416        c->base = base;
 417        c->child = NULL;
 418        if (c->data)
 419                get_thread_data()->base_cache_used += c->size;
 420        prune_base_data(c);
 421}
 422
 423static void unlink_base_data(struct base_data *c)
 424{
 425        struct base_data *base = c->base;
 426        if (base)
 427                base->child = NULL;
 428        else
 429                get_thread_data()->base_cache = NULL;
 430        free_base_data(c);
 431}
 432
 433static int is_delta_type(enum object_type type)
 434{
 435        return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 436}
 437
 438static void *unpack_entry_data(off_t offset, unsigned long size,
 439                               enum object_type type, unsigned char *sha1)
 440{
 441        static char fixed_buf[8192];
 442        int status;
 443        git_zstream stream;
 444        void *buf;
 445        git_SHA_CTX c;
 446        char hdr[32];
 447        int hdrlen;
 448
 449        if (!is_delta_type(type)) {
 450                hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), size) + 1;
 451                git_SHA1_Init(&c);
 452                git_SHA1_Update(&c, hdr, hdrlen);
 453        } else
 454                sha1 = NULL;
 455        if (type == OBJ_BLOB && size > big_file_threshold)
 456                buf = fixed_buf;
 457        else
 458                buf = xmallocz(size);
 459
 460        memset(&stream, 0, sizeof(stream));
 461        git_inflate_init(&stream);
 462        stream.next_out = buf;
 463        stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 464
 465        do {
 466                unsigned char *last_out = stream.next_out;
 467                stream.next_in = fill(1);
 468                stream.avail_in = input_len;
 469                status = git_inflate(&stream, 0);
 470                use(input_len - stream.avail_in);
 471                if (sha1)
 472                        git_SHA1_Update(&c, last_out, stream.next_out - last_out);
 473                if (buf == fixed_buf) {
 474                        stream.next_out = buf;
 475                        stream.avail_out = sizeof(fixed_buf);
 476                }
 477        } while (status == Z_OK);
 478        if (stream.total_out != size || status != Z_STREAM_END)
 479                bad_object(offset, _("inflate returned %d"), status);
 480        git_inflate_end(&stream);
 481        if (sha1)
 482                git_SHA1_Final(sha1, &c);
 483        return buf == fixed_buf ? NULL : buf;
 484}
 485
 486static void *unpack_raw_entry(struct object_entry *obj,
 487                              off_t *ofs_offset,
 488                              unsigned char *ref_sha1,
 489                              unsigned char *sha1)
 490{
 491        unsigned char *p;
 492        unsigned long size, c;
 493        off_t base_offset;
 494        unsigned shift;
 495        void *data;
 496
 497        obj->idx.offset = consumed_bytes;
 498        input_crc32 = crc32(0, NULL, 0);
 499
 500        p = fill(1);
 501        c = *p;
 502        use(1);
 503        obj->type = (c >> 4) & 7;
 504        size = (c & 15);
 505        shift = 4;
 506        while (c & 0x80) {
 507                p = fill(1);
 508                c = *p;
 509                use(1);
 510                size += (c & 0x7f) << shift;
 511                shift += 7;
 512        }
 513        obj->size = size;
 514
 515        switch (obj->type) {
 516        case OBJ_REF_DELTA:
 517                hashcpy(ref_sha1, fill(20));
 518                use(20);
 519                break;
 520        case OBJ_OFS_DELTA:
 521                p = fill(1);
 522                c = *p;
 523                use(1);
 524                base_offset = c & 127;
 525                while (c & 128) {
 526                        base_offset += 1;
 527                        if (!base_offset || MSB(base_offset, 7))
 528                                bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 529                        p = fill(1);
 530                        c = *p;
 531                        use(1);
 532                        base_offset = (base_offset << 7) + (c & 127);
 533                }
 534                *ofs_offset = obj->idx.offset - base_offset;
 535                if (*ofs_offset <= 0 || *ofs_offset >= obj->idx.offset)
 536                        bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 537                break;
 538        case OBJ_COMMIT:
 539        case OBJ_TREE:
 540        case OBJ_BLOB:
 541        case OBJ_TAG:
 542                break;
 543        default:
 544                bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 545        }
 546        obj->hdr_size = consumed_bytes - obj->idx.offset;
 547
 548        data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, sha1);
 549        obj->idx.crc32 = input_crc32;
 550        return data;
 551}
 552
 553static void *unpack_data(struct object_entry *obj,
 554                         int (*consume)(const unsigned char *, unsigned long, void *),
 555                         void *cb_data)
 556{
 557        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 558        off_t len = obj[1].idx.offset - from;
 559        unsigned char *data, *inbuf;
 560        git_zstream stream;
 561        int status;
 562
 563        data = xmallocz(consume ? 64*1024 : obj->size);
 564        inbuf = xmalloc((len < 64*1024) ? (int)len : 64*1024);
 565
 566        memset(&stream, 0, sizeof(stream));
 567        git_inflate_init(&stream);
 568        stream.next_out = data;
 569        stream.avail_out = consume ? 64*1024 : obj->size;
 570
 571        do {
 572                ssize_t n = (len < 64*1024) ? (ssize_t)len : 64*1024;
 573                n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 574                if (n < 0)
 575                        die_errno(_("cannot pread pack file"));
 576                if (!n)
 577                        die(Q_("premature end of pack file, %"PRIuMAX" byte missing",
 578                               "premature end of pack file, %"PRIuMAX" bytes missing",
 579                               (unsigned int)len),
 580                            (uintmax_t)len);
 581                from += n;
 582                len -= n;
 583                stream.next_in = inbuf;
 584                stream.avail_in = n;
 585                if (!consume)
 586                        status = git_inflate(&stream, 0);
 587                else {
 588                        do {
 589                                status = git_inflate(&stream, 0);
 590                                if (consume(data, stream.next_out - data, cb_data)) {
 591                                        free(inbuf);
 592                                        free(data);
 593                                        return NULL;
 594                                }
 595                                stream.next_out = data;
 596                                stream.avail_out = 64*1024;
 597                        } while (status == Z_OK && stream.avail_in);
 598                }
 599        } while (len && status == Z_OK && !stream.avail_in);
 600
 601        /* This has been inflated OK when first encountered, so... */
 602        if (status != Z_STREAM_END || stream.total_out != obj->size)
 603                die(_("serious inflate inconsistency"));
 604
 605        git_inflate_end(&stream);
 606        free(inbuf);
 607        if (consume) {
 608                free(data);
 609                data = NULL;
 610        }
 611        return data;
 612}
 613
 614static void *get_data_from_pack(struct object_entry *obj)
 615{
 616        return unpack_data(obj, NULL, NULL);
 617}
 618
 619static int compare_ofs_delta_bases(off_t offset1, off_t offset2,
 620                                   enum object_type type1,
 621                                   enum object_type type2)
 622{
 623        int cmp = type1 - type2;
 624        if (cmp)
 625                return cmp;
 626        return offset1 < offset2 ? -1 :
 627               offset1 > offset2 ?  1 :
 628               0;
 629}
 630
 631static int find_ofs_delta(const off_t offset, enum object_type type)
 632{
 633        int first = 0, last = nr_ofs_deltas;
 634
 635        while (first < last) {
 636                int next = (first + last) / 2;
 637                struct ofs_delta_entry *delta = &ofs_deltas[next];
 638                int cmp;
 639
 640                cmp = compare_ofs_delta_bases(offset, delta->offset,
 641                                              type, objects[delta->obj_no].type);
 642                if (!cmp)
 643                        return next;
 644                if (cmp < 0) {
 645                        last = next;
 646                        continue;
 647                }
 648                first = next+1;
 649        }
 650        return -first-1;
 651}
 652
 653static void find_ofs_delta_children(off_t offset,
 654                                    int *first_index, int *last_index,
 655                                    enum object_type type)
 656{
 657        int first = find_ofs_delta(offset, type);
 658        int last = first;
 659        int end = nr_ofs_deltas - 1;
 660
 661        if (first < 0) {
 662                *first_index = 0;
 663                *last_index = -1;
 664                return;
 665        }
 666        while (first > 0 && ofs_deltas[first - 1].offset == offset)
 667                --first;
 668        while (last < end && ofs_deltas[last + 1].offset == offset)
 669                ++last;
 670        *first_index = first;
 671        *last_index = last;
 672}
 673
 674static int compare_ref_delta_bases(const unsigned char *sha1,
 675                                   const unsigned char *sha2,
 676                                   enum object_type type1,
 677                                   enum object_type type2)
 678{
 679        int cmp = type1 - type2;
 680        if (cmp)
 681                return cmp;
 682        return hashcmp(sha1, sha2);
 683}
 684
 685static int find_ref_delta(const unsigned char *sha1, enum object_type type)
 686{
 687        int first = 0, last = nr_ref_deltas;
 688
 689        while (first < last) {
 690                int next = (first + last) / 2;
 691                struct ref_delta_entry *delta = &ref_deltas[next];
 692                int cmp;
 693
 694                cmp = compare_ref_delta_bases(sha1, delta->sha1,
 695                                              type, objects[delta->obj_no].type);
 696                if (!cmp)
 697                        return next;
 698                if (cmp < 0) {
 699                        last = next;
 700                        continue;
 701                }
 702                first = next+1;
 703        }
 704        return -first-1;
 705}
 706
 707static void find_ref_delta_children(const unsigned char *sha1,
 708                                    int *first_index, int *last_index,
 709                                    enum object_type type)
 710{
 711        int first = find_ref_delta(sha1, type);
 712        int last = first;
 713        int end = nr_ref_deltas - 1;
 714
 715        if (first < 0) {
 716                *first_index = 0;
 717                *last_index = -1;
 718                return;
 719        }
 720        while (first > 0 && !hashcmp(ref_deltas[first - 1].sha1, sha1))
 721                --first;
 722        while (last < end && !hashcmp(ref_deltas[last + 1].sha1, sha1))
 723                ++last;
 724        *first_index = first;
 725        *last_index = last;
 726}
 727
 728struct compare_data {
 729        struct object_entry *entry;
 730        struct git_istream *st;
 731        unsigned char *buf;
 732        unsigned long buf_size;
 733};
 734
 735static int compare_objects(const unsigned char *buf, unsigned long size,
 736                           void *cb_data)
 737{
 738        struct compare_data *data = cb_data;
 739
 740        if (data->buf_size < size) {
 741                free(data->buf);
 742                data->buf = xmalloc(size);
 743                data->buf_size = size;
 744        }
 745
 746        while (size) {
 747                ssize_t len = read_istream(data->st, data->buf, size);
 748                if (len == 0)
 749                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 750                            oid_to_hex(&data->entry->idx.oid));
 751                if (len < 0)
 752                        die(_("unable to read %s"),
 753                            oid_to_hex(&data->entry->idx.oid));
 754                if (memcmp(buf, data->buf, len))
 755                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 756                            oid_to_hex(&data->entry->idx.oid));
 757                size -= len;
 758                buf += len;
 759        }
 760        return 0;
 761}
 762
 763static int check_collison(struct object_entry *entry)
 764{
 765        struct compare_data data;
 766        enum object_type type;
 767        unsigned long size;
 768
 769        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 770                return -1;
 771
 772        memset(&data, 0, sizeof(data));
 773        data.entry = entry;
 774        data.st = open_istream(entry->idx.oid.hash, &type, &size, NULL);
 775        if (!data.st)
 776                return -1;
 777        if (size != entry->size || type != entry->type)
 778                die(_("SHA1 COLLISION FOUND WITH %s !"),
 779                    oid_to_hex(&entry->idx.oid));
 780        unpack_data(entry, compare_objects, &data);
 781        close_istream(data.st);
 782        free(data.buf);
 783        return 0;
 784}
 785
 786static void sha1_object(const void *data, struct object_entry *obj_entry,
 787                        unsigned long size, enum object_type type,
 788                        const struct object_id *oid)
 789{
 790        void *new_data = NULL;
 791        int collision_test_needed = 0;
 792
 793        assert(data || obj_entry);
 794
 795        if (startup_info->have_repository) {
 796                read_lock();
 797                collision_test_needed = has_sha1_file_with_flags(oid->hash, HAS_SHA1_QUICK);
 798                read_unlock();
 799        }
 800
 801        if (collision_test_needed && !data) {
 802                read_lock();
 803                if (!check_collison(obj_entry))
 804                        collision_test_needed = 0;
 805                read_unlock();
 806        }
 807        if (collision_test_needed) {
 808                void *has_data;
 809                enum object_type has_type;
 810                unsigned long has_size;
 811                read_lock();
 812                has_type = sha1_object_info(oid->hash, &has_size);
 813                if (has_type < 0)
 814                        die(_("cannot read existing object info %s"), oid_to_hex(oid));
 815                if (has_type != type || has_size != size)
 816                        die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 817                has_data = read_sha1_file(oid->hash, &has_type, &has_size);
 818                read_unlock();
 819                if (!data)
 820                        data = new_data = get_data_from_pack(obj_entry);
 821                if (!has_data)
 822                        die(_("cannot read existing object %s"), oid_to_hex(oid));
 823                if (size != has_size || type != has_type ||
 824                    memcmp(data, has_data, size) != 0)
 825                        die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 826                free(has_data);
 827        }
 828
 829        if (strict) {
 830                read_lock();
 831                if (type == OBJ_BLOB) {
 832                        struct blob *blob = lookup_blob(oid->hash);
 833                        if (blob)
 834                                blob->object.flags |= FLAG_CHECKED;
 835                        else
 836                                die(_("invalid blob object %s"), oid_to_hex(oid));
 837                } else {
 838                        struct object *obj;
 839                        int eaten;
 840                        void *buf = (void *) data;
 841
 842                        assert(data && "data can only be NULL for large _blobs_");
 843
 844                        /*
 845                         * we do not need to free the memory here, as the
 846                         * buf is deleted by the caller.
 847                         */
 848                        obj = parse_object_buffer(oid->hash, type, size, buf, &eaten);
 849                        if (!obj)
 850                                die(_("invalid %s"), typename(type));
 851                        if (do_fsck_object &&
 852                            fsck_object(obj, buf, size, &fsck_options))
 853                                die(_("Error in object"));
 854                        if (fsck_walk(obj, NULL, &fsck_options))
 855                                die(_("Not all child objects of %s are reachable"), oid_to_hex(&obj->oid));
 856
 857                        if (obj->type == OBJ_TREE) {
 858                                struct tree *item = (struct tree *) obj;
 859                                item->buffer = NULL;
 860                                obj->parsed = 0;
 861                        }
 862                        if (obj->type == OBJ_COMMIT) {
 863                                struct commit *commit = (struct commit *) obj;
 864                                if (detach_commit_buffer(commit, NULL) != data)
 865                                        die("BUG: parse_object_buffer transmogrified our buffer");
 866                        }
 867                        obj->flags |= FLAG_CHECKED;
 868                }
 869                read_unlock();
 870        }
 871
 872        free(new_data);
 873}
 874
 875/*
 876 * This function is part of find_unresolved_deltas(). There are two
 877 * walkers going in the opposite ways.
 878 *
 879 * The first one in find_unresolved_deltas() traverses down from
 880 * parent node to children, deflating nodes along the way. However,
 881 * memory for deflated nodes is limited by delta_base_cache_limit, so
 882 * at some point parent node's deflated content may be freed.
 883 *
 884 * The second walker is this function, which goes from current node up
 885 * to top parent if necessary to deflate the node. In normal
 886 * situation, its parent node would be already deflated, so it just
 887 * needs to apply delta.
 888 *
 889 * In the worst case scenario, parent node is no longer deflated because
 890 * we're running out of delta_base_cache_limit; we need to re-deflate
 891 * parents, possibly up to the top base.
 892 *
 893 * All deflated objects here are subject to be freed if we exceed
 894 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 895 * just need to make sure the last node is not freed.
 896 */
 897static void *get_base_data(struct base_data *c)
 898{
 899        if (!c->data) {
 900                struct object_entry *obj = c->obj;
 901                struct base_data **delta = NULL;
 902                int delta_nr = 0, delta_alloc = 0;
 903
 904                while (is_delta_type(c->obj->type) && !c->data) {
 905                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 906                        delta[delta_nr++] = c;
 907                        c = c->base;
 908                }
 909                if (!delta_nr) {
 910                        c->data = get_data_from_pack(obj);
 911                        c->size = obj->size;
 912                        get_thread_data()->base_cache_used += c->size;
 913                        prune_base_data(c);
 914                }
 915                for (; delta_nr > 0; delta_nr--) {
 916                        void *base, *raw;
 917                        c = delta[delta_nr - 1];
 918                        obj = c->obj;
 919                        base = get_base_data(c->base);
 920                        raw = get_data_from_pack(obj);
 921                        c->data = patch_delta(
 922                                base, c->base->size,
 923                                raw, obj->size,
 924                                &c->size);
 925                        free(raw);
 926                        if (!c->data)
 927                                bad_object(obj->idx.offset, _("failed to apply delta"));
 928                        get_thread_data()->base_cache_used += c->size;
 929                        prune_base_data(c);
 930                }
 931                free(delta);
 932        }
 933        return c->data;
 934}
 935
 936static void resolve_delta(struct object_entry *delta_obj,
 937                          struct base_data *base, struct base_data *result)
 938{
 939        void *base_data, *delta_data;
 940
 941        if (show_stat) {
 942                int i = delta_obj - objects;
 943                int j = base->obj - objects;
 944                obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 945                deepest_delta_lock();
 946                if (deepest_delta < obj_stat[i].delta_depth)
 947                        deepest_delta = obj_stat[i].delta_depth;
 948                deepest_delta_unlock();
 949                obj_stat[i].base_object_no = j;
 950        }
 951        delta_data = get_data_from_pack(delta_obj);
 952        base_data = get_base_data(base);
 953        result->obj = delta_obj;
 954        result->data = patch_delta(base_data, base->size,
 955                                   delta_data, delta_obj->size, &result->size);
 956        free(delta_data);
 957        if (!result->data)
 958                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 959        hash_sha1_file(result->data, result->size,
 960                       typename(delta_obj->real_type),
 961                       delta_obj->idx.oid.hash);
 962        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 963                    &delta_obj->idx.oid);
 964        counter_lock();
 965        nr_resolved_deltas++;
 966        counter_unlock();
 967}
 968
 969/*
 970 * Standard boolean compare-and-swap: atomically check whether "*type" is
 971 * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 972 * and return false.
 973 */
 974static int compare_and_swap_type(signed char *type,
 975                                 enum object_type want,
 976                                 enum object_type set)
 977{
 978        enum object_type old;
 979
 980        type_cas_lock();
 981        old = *type;
 982        if (old == want)
 983                *type = set;
 984        type_cas_unlock();
 985
 986        return old == want;
 987}
 988
 989static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 990                                                  struct base_data *prev_base)
 991{
 992        if (base->ref_last == -1 && base->ofs_last == -1) {
 993                find_ref_delta_children(base->obj->idx.oid.hash,
 994                                        &base->ref_first, &base->ref_last,
 995                                        OBJ_REF_DELTA);
 996
 997                find_ofs_delta_children(base->obj->idx.offset,
 998                                        &base->ofs_first, &base->ofs_last,
 999                                        OBJ_OFS_DELTA);
1000
1001                if (base->ref_last == -1 && base->ofs_last == -1) {
1002                        free(base->data);
1003                        return NULL;
1004                }
1005
1006                link_base_data(prev_base, base);
1007        }
1008
1009        if (base->ref_first <= base->ref_last) {
1010                struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
1011                struct base_data *result = alloc_base_data();
1012
1013                if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
1014                                           base->obj->real_type))
1015                        die("BUG: child->real_type != OBJ_REF_DELTA");
1016
1017                resolve_delta(child, base, result);
1018                if (base->ref_first == base->ref_last && base->ofs_last == -1)
1019                        free_base_data(base);
1020
1021                base->ref_first++;
1022                return result;
1023        }
1024
1025        if (base->ofs_first <= base->ofs_last) {
1026                struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
1027                struct base_data *result = alloc_base_data();
1028
1029                assert(child->real_type == OBJ_OFS_DELTA);
1030                child->real_type = base->obj->real_type;
1031                resolve_delta(child, base, result);
1032                if (base->ofs_first == base->ofs_last)
1033                        free_base_data(base);
1034
1035                base->ofs_first++;
1036                return result;
1037        }
1038
1039        unlink_base_data(base);
1040        return NULL;
1041}
1042
1043static void find_unresolved_deltas(struct base_data *base)
1044{
1045        struct base_data *new_base, *prev_base = NULL;
1046        for (;;) {
1047                new_base = find_unresolved_deltas_1(base, prev_base);
1048
1049                if (new_base) {
1050                        prev_base = base;
1051                        base = new_base;
1052                } else {
1053                        free(base);
1054                        base = prev_base;
1055                        if (!base)
1056                                return;
1057                        prev_base = base->base;
1058                }
1059        }
1060}
1061
1062static int compare_ofs_delta_entry(const void *a, const void *b)
1063{
1064        const struct ofs_delta_entry *delta_a = a;
1065        const struct ofs_delta_entry *delta_b = b;
1066
1067        return delta_a->offset < delta_b->offset ? -1 :
1068               delta_a->offset > delta_b->offset ?  1 :
1069               0;
1070}
1071
1072static int compare_ref_delta_entry(const void *a, const void *b)
1073{
1074        const struct ref_delta_entry *delta_a = a;
1075        const struct ref_delta_entry *delta_b = b;
1076
1077        return hashcmp(delta_a->sha1, delta_b->sha1);
1078}
1079
1080static void resolve_base(struct object_entry *obj)
1081{
1082        struct base_data *base_obj = alloc_base_data();
1083        base_obj->obj = obj;
1084        base_obj->data = NULL;
1085        find_unresolved_deltas(base_obj);
1086}
1087
1088#ifndef NO_PTHREADS
1089static void *threaded_second_pass(void *data)
1090{
1091        set_thread_data(data);
1092        for (;;) {
1093                int i;
1094                counter_lock();
1095                display_progress(progress, nr_resolved_deltas);
1096                counter_unlock();
1097                work_lock();
1098                while (nr_dispatched < nr_objects &&
1099                       is_delta_type(objects[nr_dispatched].type))
1100                        nr_dispatched++;
1101                if (nr_dispatched >= nr_objects) {
1102                        work_unlock();
1103                        break;
1104                }
1105                i = nr_dispatched++;
1106                work_unlock();
1107
1108                resolve_base(&objects[i]);
1109        }
1110        return NULL;
1111}
1112#endif
1113
1114/*
1115 * First pass:
1116 * - find locations of all objects;
1117 * - calculate SHA1 of all non-delta objects;
1118 * - remember base (SHA1 or offset) for all deltas.
1119 */
1120static void parse_pack_objects(unsigned char *sha1)
1121{
1122        int i, nr_delays = 0;
1123        struct ofs_delta_entry *ofs_delta = ofs_deltas;
1124        unsigned char ref_delta_sha1[20];
1125        struct stat st;
1126
1127        if (verbose)
1128                progress = start_progress(
1129                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1130                                nr_objects);
1131        for (i = 0; i < nr_objects; i++) {
1132                struct object_entry *obj = &objects[i];
1133                void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1134                                              ref_delta_sha1,
1135                                              obj->idx.oid.hash);
1136                obj->real_type = obj->type;
1137                if (obj->type == OBJ_OFS_DELTA) {
1138                        nr_ofs_deltas++;
1139                        ofs_delta->obj_no = i;
1140                        ofs_delta++;
1141                } else if (obj->type == OBJ_REF_DELTA) {
1142                        ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1143                        hashcpy(ref_deltas[nr_ref_deltas].sha1, ref_delta_sha1);
1144                        ref_deltas[nr_ref_deltas].obj_no = i;
1145                        nr_ref_deltas++;
1146                } else if (!data) {
1147                        /* large blobs, check later */
1148                        obj->real_type = OBJ_BAD;
1149                        nr_delays++;
1150                } else
1151                        sha1_object(data, NULL, obj->size, obj->type,
1152                                    &obj->idx.oid);
1153                free(data);
1154                display_progress(progress, i+1);
1155        }
1156        objects[i].idx.offset = consumed_bytes;
1157        stop_progress(&progress);
1158
1159        /* Check pack integrity */
1160        flush();
1161        git_SHA1_Final(sha1, &input_ctx);
1162        if (hashcmp(fill(20), sha1))
1163                die(_("pack is corrupted (SHA1 mismatch)"));
1164        use(20);
1165
1166        /* If input_fd is a file, we should have reached its end now. */
1167        if (fstat(input_fd, &st))
1168                die_errno(_("cannot fstat packfile"));
1169        if (S_ISREG(st.st_mode) &&
1170                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1171                die(_("pack has junk at the end"));
1172
1173        for (i = 0; i < nr_objects; i++) {
1174                struct object_entry *obj = &objects[i];
1175                if (obj->real_type != OBJ_BAD)
1176                        continue;
1177                obj->real_type = obj->type;
1178                sha1_object(NULL, obj, obj->size, obj->type,
1179                            &obj->idx.oid);
1180                nr_delays--;
1181        }
1182        if (nr_delays)
1183                die(_("confusion beyond insanity in parse_pack_objects()"));
1184}
1185
1186/*
1187 * Second pass:
1188 * - for all non-delta objects, look if it is used as a base for
1189 *   deltas;
1190 * - if used as a base, uncompress the object and apply all deltas,
1191 *   recursively checking if the resulting object is used as a base
1192 *   for some more deltas.
1193 */
1194static void resolve_deltas(void)
1195{
1196        int i;
1197
1198        if (!nr_ofs_deltas && !nr_ref_deltas)
1199                return;
1200
1201        /* Sort deltas by base SHA1/offset for fast searching */
1202        QSORT(ofs_deltas, nr_ofs_deltas, compare_ofs_delta_entry);
1203        QSORT(ref_deltas, nr_ref_deltas, compare_ref_delta_entry);
1204
1205        if (verbose || show_resolving_progress)
1206                progress = start_progress(_("Resolving deltas"),
1207                                          nr_ref_deltas + nr_ofs_deltas);
1208
1209#ifndef NO_PTHREADS
1210        nr_dispatched = 0;
1211        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1212                init_thread();
1213                for (i = 0; i < nr_threads; i++) {
1214                        int ret = pthread_create(&thread_data[i].thread, NULL,
1215                                                 threaded_second_pass, thread_data + i);
1216                        if (ret)
1217                                die(_("unable to create thread: %s"),
1218                                    strerror(ret));
1219                }
1220                for (i = 0; i < nr_threads; i++)
1221                        pthread_join(thread_data[i].thread, NULL);
1222                cleanup_thread();
1223                return;
1224        }
1225#endif
1226
1227        for (i = 0; i < nr_objects; i++) {
1228                struct object_entry *obj = &objects[i];
1229
1230                if (is_delta_type(obj->type))
1231                        continue;
1232                resolve_base(obj);
1233                display_progress(progress, nr_resolved_deltas);
1234        }
1235}
1236
1237/*
1238 * Third pass:
1239 * - append objects to convert thin pack to full pack if required
1240 * - write the final 20-byte SHA-1
1241 */
1242static void fix_unresolved_deltas(struct sha1file *f);
1243static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
1244{
1245        if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1246                stop_progress(&progress);
1247                /* Flush remaining pack final 20-byte SHA1. */
1248                flush();
1249                return;
1250        }
1251
1252        if (fix_thin_pack) {
1253                struct sha1file *f;
1254                unsigned char read_sha1[20], tail_sha1[20];
1255                struct strbuf msg = STRBUF_INIT;
1256                int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1257                int nr_objects_initial = nr_objects;
1258                if (nr_unresolved <= 0)
1259                        die(_("confusion beyond insanity"));
1260                REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1261                memset(objects + nr_objects + 1, 0,
1262                       nr_unresolved * sizeof(*objects));
1263                f = sha1fd(output_fd, curr_pack);
1264                fix_unresolved_deltas(f);
1265                strbuf_addf(&msg, Q_("completed with %d local object",
1266                                     "completed with %d local objects",
1267                                     nr_objects - nr_objects_initial),
1268                            nr_objects - nr_objects_initial);
1269                stop_progress_msg(&progress, msg.buf);
1270                strbuf_release(&msg);
1271                sha1close(f, tail_sha1, 0);
1272                hashcpy(read_sha1, pack_sha1);
1273                fixup_pack_header_footer(output_fd, pack_sha1,
1274                                         curr_pack, nr_objects,
1275                                         read_sha1, consumed_bytes-20);
1276                if (hashcmp(read_sha1, tail_sha1) != 0)
1277                        die(_("Unexpected tail checksum for %s "
1278                              "(disk corruption?)"), curr_pack);
1279        }
1280        if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1281                die(Q_("pack has %d unresolved delta",
1282                       "pack has %d unresolved deltas",
1283                       nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1284                    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1285}
1286
1287static int write_compressed(struct sha1file *f, void *in, unsigned int size)
1288{
1289        git_zstream stream;
1290        int status;
1291        unsigned char outbuf[4096];
1292
1293        git_deflate_init(&stream, zlib_compression_level);
1294        stream.next_in = in;
1295        stream.avail_in = size;
1296
1297        do {
1298                stream.next_out = outbuf;
1299                stream.avail_out = sizeof(outbuf);
1300                status = git_deflate(&stream, Z_FINISH);
1301                sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
1302        } while (status == Z_OK);
1303
1304        if (status != Z_STREAM_END)
1305                die(_("unable to deflate appended object (%d)"), status);
1306        size = stream.total_out;
1307        git_deflate_end(&stream);
1308        return size;
1309}
1310
1311static struct object_entry *append_obj_to_pack(struct sha1file *f,
1312                               const unsigned char *sha1, void *buf,
1313                               unsigned long size, enum object_type type)
1314{
1315        struct object_entry *obj = &objects[nr_objects++];
1316        unsigned char header[10];
1317        unsigned long s = size;
1318        int n = 0;
1319        unsigned char c = (type << 4) | (s & 15);
1320        s >>= 4;
1321        while (s) {
1322                header[n++] = c | 0x80;
1323                c = s & 0x7f;
1324                s >>= 7;
1325        }
1326        header[n++] = c;
1327        crc32_begin(f);
1328        sha1write(f, header, n);
1329        obj[0].size = size;
1330        obj[0].hdr_size = n;
1331        obj[0].type = type;
1332        obj[0].real_type = type;
1333        obj[1].idx.offset = obj[0].idx.offset + n;
1334        obj[1].idx.offset += write_compressed(f, buf, size);
1335        obj[0].idx.crc32 = crc32_end(f);
1336        sha1flush(f);
1337        hashcpy(obj->idx.oid.hash, sha1);
1338        return obj;
1339}
1340
1341static int delta_pos_compare(const void *_a, const void *_b)
1342{
1343        struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1344        struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1345        return a->obj_no - b->obj_no;
1346}
1347
1348static void fix_unresolved_deltas(struct sha1file *f)
1349{
1350        struct ref_delta_entry **sorted_by_pos;
1351        int i;
1352
1353        /*
1354         * Since many unresolved deltas may well be themselves base objects
1355         * for more unresolved deltas, we really want to include the
1356         * smallest number of base objects that would cover as much delta
1357         * as possible by picking the
1358         * trunc deltas first, allowing for other deltas to resolve without
1359         * additional base objects.  Since most base objects are to be found
1360         * before deltas depending on them, a good heuristic is to start
1361         * resolving deltas in the same order as their position in the pack.
1362         */
1363        ALLOC_ARRAY(sorted_by_pos, nr_ref_deltas);
1364        for (i = 0; i < nr_ref_deltas; i++)
1365                sorted_by_pos[i] = &ref_deltas[i];
1366        QSORT(sorted_by_pos, nr_ref_deltas, delta_pos_compare);
1367
1368        for (i = 0; i < nr_ref_deltas; i++) {
1369                struct ref_delta_entry *d = sorted_by_pos[i];
1370                enum object_type type;
1371                struct base_data *base_obj = alloc_base_data();
1372
1373                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1374                        continue;
1375                base_obj->data = read_sha1_file(d->sha1, &type, &base_obj->size);
1376                if (!base_obj->data)
1377                        continue;
1378
1379                if (check_sha1_signature(d->sha1, base_obj->data,
1380                                base_obj->size, typename(type)))
1381                        die(_("local object %s is corrupt"), sha1_to_hex(d->sha1));
1382                base_obj->obj = append_obj_to_pack(f, d->sha1,
1383                                        base_obj->data, base_obj->size, type);
1384                find_unresolved_deltas(base_obj);
1385                display_progress(progress, nr_resolved_deltas);
1386        }
1387        free(sorted_by_pos);
1388}
1389
1390static void final(const char *final_pack_name, const char *curr_pack_name,
1391                  const char *final_index_name, const char *curr_index_name,
1392                  const char *keep_name, const char *keep_msg,
1393                  unsigned char *sha1)
1394{
1395        const char *report = "pack";
1396        struct strbuf pack_name = STRBUF_INIT;
1397        struct strbuf index_name = STRBUF_INIT;
1398        struct strbuf keep_name_buf = STRBUF_INIT;
1399        int err;
1400
1401        if (!from_stdin) {
1402                close(input_fd);
1403        } else {
1404                fsync_or_die(output_fd, curr_pack_name);
1405                err = close(output_fd);
1406                if (err)
1407                        die_errno(_("error while closing pack file"));
1408        }
1409
1410        if (keep_msg) {
1411                int keep_fd, keep_msg_len = strlen(keep_msg);
1412
1413                if (!keep_name)
1414                        keep_name = odb_pack_name(&keep_name_buf, sha1, "keep");
1415
1416                keep_fd = odb_pack_keep(keep_name);
1417                if (keep_fd < 0) {
1418                        if (errno != EEXIST)
1419                                die_errno(_("cannot write keep file '%s'"),
1420                                          keep_name);
1421                } else {
1422                        if (keep_msg_len > 0) {
1423                                write_or_die(keep_fd, keep_msg, keep_msg_len);
1424                                write_or_die(keep_fd, "\n", 1);
1425                        }
1426                        if (close(keep_fd) != 0)
1427                                die_errno(_("cannot close written keep file '%s'"),
1428                                          keep_name);
1429                        report = "keep";
1430                }
1431        }
1432
1433        if (final_pack_name != curr_pack_name) {
1434                if (!final_pack_name)
1435                        final_pack_name = odb_pack_name(&pack_name, sha1, "pack");
1436                if (finalize_object_file(curr_pack_name, final_pack_name))
1437                        die(_("cannot store pack file"));
1438        } else if (from_stdin)
1439                chmod(final_pack_name, 0444);
1440
1441        if (final_index_name != curr_index_name) {
1442                if (!final_index_name)
1443                        final_index_name = odb_pack_name(&index_name, sha1, "idx");
1444                if (finalize_object_file(curr_index_name, final_index_name))
1445                        die(_("cannot store index file"));
1446        } else
1447                chmod(final_index_name, 0444);
1448
1449        if (!from_stdin) {
1450                printf("%s\n", sha1_to_hex(sha1));
1451        } else {
1452                struct strbuf buf = STRBUF_INIT;
1453
1454                strbuf_addf(&buf, "%s\t%s\n", report, sha1_to_hex(sha1));
1455                write_or_die(1, buf.buf, buf.len);
1456                strbuf_release(&buf);
1457
1458                /*
1459                 * Let's just mimic git-unpack-objects here and write
1460                 * the last part of the input buffer to stdout.
1461                 */
1462                while (input_len) {
1463                        err = xwrite(1, input_buffer + input_offset, input_len);
1464                        if (err <= 0)
1465                                break;
1466                        input_len -= err;
1467                        input_offset += err;
1468                }
1469        }
1470
1471        strbuf_release(&index_name);
1472        strbuf_release(&pack_name);
1473        strbuf_release(&keep_name_buf);
1474}
1475
1476static int git_index_pack_config(const char *k, const char *v, void *cb)
1477{
1478        struct pack_idx_option *opts = cb;
1479
1480        if (!strcmp(k, "pack.indexversion")) {
1481                opts->version = git_config_int(k, v);
1482                if (opts->version > 2)
1483                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1484                return 0;
1485        }
1486        if (!strcmp(k, "pack.threads")) {
1487                nr_threads = git_config_int(k, v);
1488                if (nr_threads < 0)
1489                        die(_("invalid number of threads specified (%d)"),
1490                            nr_threads);
1491#ifdef NO_PTHREADS
1492                if (nr_threads != 1)
1493                        warning(_("no threads support, ignoring %s"), k);
1494                nr_threads = 1;
1495#endif
1496                return 0;
1497        }
1498        return git_default_config(k, v, cb);
1499}
1500
1501static int cmp_uint32(const void *a_, const void *b_)
1502{
1503        uint32_t a = *((uint32_t *)a_);
1504        uint32_t b = *((uint32_t *)b_);
1505
1506        return (a < b) ? -1 : (a != b);
1507}
1508
1509static void read_v2_anomalous_offsets(struct packed_git *p,
1510                                      struct pack_idx_option *opts)
1511{
1512        const uint32_t *idx1, *idx2;
1513        uint32_t i;
1514
1515        /* The address of the 4-byte offset table */
1516        idx1 = (((const uint32_t *)p->index_data)
1517                + 2 /* 8-byte header */
1518                + 256 /* fan out */
1519                + 5 * p->num_objects /* 20-byte SHA-1 table */
1520                + p->num_objects /* CRC32 table */
1521                );
1522
1523        /* The address of the 8-byte offset table */
1524        idx2 = idx1 + p->num_objects;
1525
1526        for (i = 0; i < p->num_objects; i++) {
1527                uint32_t off = ntohl(idx1[i]);
1528                if (!(off & 0x80000000))
1529                        continue;
1530                off = off & 0x7fffffff;
1531                check_pack_index_ptr(p, &idx2[off * 2]);
1532                if (idx2[off * 2])
1533                        continue;
1534                /*
1535                 * The real offset is ntohl(idx2[off * 2]) in high 4
1536                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1537                 * octets.  But idx2[off * 2] is Zero!!!
1538                 */
1539                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1540                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1541        }
1542
1543        QSORT(opts->anomaly, opts->anomaly_nr, cmp_uint32);
1544}
1545
1546static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1547{
1548        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1549
1550        if (!p)
1551                die(_("Cannot open existing pack file '%s'"), pack_name);
1552        if (open_pack_index(p))
1553                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1554
1555        /* Read the attributes from the existing idx file */
1556        opts->version = p->index_version;
1557
1558        if (opts->version == 2)
1559                read_v2_anomalous_offsets(p, opts);
1560
1561        /*
1562         * Get rid of the idx file as we do not need it anymore.
1563         * NEEDSWORK: extract this bit from free_pack_by_name() in
1564         * sha1_file.c, perhaps?  It shouldn't matter very much as we
1565         * know we haven't installed this pack (hence we never have
1566         * read anything from it).
1567         */
1568        close_pack_index(p);
1569        free(p);
1570}
1571
1572static void show_pack_info(int stat_only)
1573{
1574        int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1575        unsigned long *chain_histogram = NULL;
1576
1577        if (deepest_delta)
1578                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1579
1580        for (i = 0; i < nr_objects; i++) {
1581                struct object_entry *obj = &objects[i];
1582
1583                if (is_delta_type(obj->type))
1584                        chain_histogram[obj_stat[i].delta_depth - 1]++;
1585                if (stat_only)
1586                        continue;
1587                printf("%s %-6s %lu %lu %"PRIuMAX,
1588                       oid_to_hex(&obj->idx.oid),
1589                       typename(obj->real_type), obj->size,
1590                       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1591                       (uintmax_t)obj->idx.offset);
1592                if (is_delta_type(obj->type)) {
1593                        struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1594                        printf(" %u %s", obj_stat[i].delta_depth,
1595                               oid_to_hex(&bobj->idx.oid));
1596                }
1597                putchar('\n');
1598        }
1599
1600        if (baseobjects)
1601                printf_ln(Q_("non delta: %d object",
1602                             "non delta: %d objects",
1603                             baseobjects),
1604                          baseobjects);
1605        for (i = 0; i < deepest_delta; i++) {
1606                if (!chain_histogram[i])
1607                        continue;
1608                printf_ln(Q_("chain length = %d: %lu object",
1609                             "chain length = %d: %lu objects",
1610                             chain_histogram[i]),
1611                          i + 1,
1612                          chain_histogram[i]);
1613        }
1614}
1615
1616static const char *derive_filename(const char *pack_name, const char *suffix,
1617                                   struct strbuf *buf)
1618{
1619        size_t len;
1620        if (!strip_suffix(pack_name, ".pack", &len))
1621                die(_("packfile name '%s' does not end with '.pack'"),
1622                    pack_name);
1623        strbuf_add(buf, pack_name, len);
1624        strbuf_addstr(buf, suffix);
1625        return buf->buf;
1626}
1627
1628int cmd_index_pack(int argc, const char **argv, const char *prefix)
1629{
1630        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1631        const char *curr_index;
1632        const char *index_name = NULL, *pack_name = NULL;
1633        const char *keep_name = NULL, *keep_msg = NULL;
1634        struct strbuf index_name_buf = STRBUF_INIT,
1635                      keep_name_buf = STRBUF_INIT;
1636        struct pack_idx_entry **idx_objects;
1637        struct pack_idx_option opts;
1638        unsigned char pack_sha1[20];
1639        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1640        int report_end_of_input = 0;
1641
1642        if (argc == 2 && !strcmp(argv[1], "-h"))
1643                usage(index_pack_usage);
1644
1645        check_replace_refs = 0;
1646        fsck_options.walk = mark_link;
1647
1648        reset_pack_idx_option(&opts);
1649        git_config(git_index_pack_config, &opts);
1650        if (prefix && chdir(prefix))
1651                die(_("Cannot come back to cwd"));
1652
1653        for (i = 1; i < argc; i++) {
1654                const char *arg = argv[i];
1655
1656                if (*arg == '-') {
1657                        if (!strcmp(arg, "--stdin")) {
1658                                from_stdin = 1;
1659                        } else if (!strcmp(arg, "--fix-thin")) {
1660                                fix_thin_pack = 1;
1661                        } else if (!strcmp(arg, "--strict")) {
1662                                strict = 1;
1663                                do_fsck_object = 1;
1664                        } else if (skip_prefix(arg, "--strict=", &arg)) {
1665                                strict = 1;
1666                                do_fsck_object = 1;
1667                                fsck_set_msg_types(&fsck_options, arg);
1668                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1669                                strict = 1;
1670                                check_self_contained_and_connected = 1;
1671                        } else if (!strcmp(arg, "--verify")) {
1672                                verify = 1;
1673                        } else if (!strcmp(arg, "--verify-stat")) {
1674                                verify = 1;
1675                                show_stat = 1;
1676                        } else if (!strcmp(arg, "--verify-stat-only")) {
1677                                verify = 1;
1678                                show_stat = 1;
1679                                stat_only = 1;
1680                        } else if (!strcmp(arg, "--keep")) {
1681                                keep_msg = "";
1682                        } else if (starts_with(arg, "--keep=")) {
1683                                keep_msg = arg + 7;
1684                        } else if (starts_with(arg, "--threads=")) {
1685                                char *end;
1686                                nr_threads = strtoul(arg+10, &end, 0);
1687                                if (!arg[10] || *end || nr_threads < 0)
1688                                        usage(index_pack_usage);
1689#ifdef NO_PTHREADS
1690                                if (nr_threads != 1)
1691                                        warning(_("no threads support, "
1692                                                  "ignoring %s"), arg);
1693                                nr_threads = 1;
1694#endif
1695                        } else if (starts_with(arg, "--pack_header=")) {
1696                                struct pack_header *hdr;
1697                                char *c;
1698
1699                                hdr = (struct pack_header *)input_buffer;
1700                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1701                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1702                                if (*c != ',')
1703                                        die(_("bad %s"), arg);
1704                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1705                                if (*c)
1706                                        die(_("bad %s"), arg);
1707                                input_len = sizeof(*hdr);
1708                        } else if (!strcmp(arg, "-v")) {
1709                                verbose = 1;
1710                        } else if (!strcmp(arg, "--show-resolving-progress")) {
1711                                show_resolving_progress = 1;
1712                        } else if (!strcmp(arg, "--report-end-of-input")) {
1713                                report_end_of_input = 1;
1714                        } else if (!strcmp(arg, "-o")) {
1715                                if (index_name || (i+1) >= argc)
1716                                        usage(index_pack_usage);
1717                                index_name = argv[++i];
1718                        } else if (starts_with(arg, "--index-version=")) {
1719                                char *c;
1720                                opts.version = strtoul(arg + 16, &c, 10);
1721                                if (opts.version > 2)
1722                                        die(_("bad %s"), arg);
1723                                if (*c == ',')
1724                                        opts.off32_limit = strtoul(c+1, &c, 0);
1725                                if (*c || opts.off32_limit & 0x80000000)
1726                                        die(_("bad %s"), arg);
1727                        } else if (skip_prefix(arg, "--max-input-size=", &arg)) {
1728                                max_input_size = strtoumax(arg, NULL, 10);
1729                        } else
1730                                usage(index_pack_usage);
1731                        continue;
1732                }
1733
1734                if (pack_name)
1735                        usage(index_pack_usage);
1736                pack_name = arg;
1737        }
1738
1739        if (!pack_name && !from_stdin)
1740                usage(index_pack_usage);
1741        if (fix_thin_pack && !from_stdin)
1742                die(_("--fix-thin cannot be used without --stdin"));
1743        if (from_stdin && !startup_info->have_repository)
1744                die(_("--stdin requires a git repository"));
1745        if (!index_name && pack_name)
1746                index_name = derive_filename(pack_name, ".idx", &index_name_buf);
1747        if (keep_msg && !keep_name && pack_name)
1748                keep_name = derive_filename(pack_name, ".keep", &keep_name_buf);
1749
1750        if (verify) {
1751                if (!index_name)
1752                        die(_("--verify with no packfile name given"));
1753                read_idx_option(&opts, index_name);
1754                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1755        }
1756        if (strict)
1757                opts.flags |= WRITE_IDX_STRICT;
1758
1759#ifndef NO_PTHREADS
1760        if (!nr_threads) {
1761                nr_threads = online_cpus();
1762                /* An experiment showed that more threads does not mean faster */
1763                if (nr_threads > 3)
1764                        nr_threads = 3;
1765        }
1766#endif
1767
1768        curr_pack = open_pack_file(pack_name);
1769        parse_pack_header();
1770        objects = xcalloc(st_add(nr_objects, 1), sizeof(struct object_entry));
1771        if (show_stat)
1772                obj_stat = xcalloc(st_add(nr_objects, 1), sizeof(struct object_stat));
1773        ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
1774        parse_pack_objects(pack_sha1);
1775        if (report_end_of_input)
1776                write_in_full(2, "\0", 1);
1777        resolve_deltas();
1778        conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1779        free(ofs_deltas);
1780        free(ref_deltas);
1781        if (strict)
1782                foreign_nr = check_objects();
1783
1784        if (show_stat)
1785                show_pack_info(stat_only);
1786
1787        ALLOC_ARRAY(idx_objects, nr_objects);
1788        for (i = 0; i < nr_objects; i++)
1789                idx_objects[i] = &objects[i].idx;
1790        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1791        free(idx_objects);
1792
1793        if (!verify)
1794                final(pack_name, curr_pack,
1795                      index_name, curr_index,
1796                      keep_name, keep_msg,
1797                      pack_sha1);
1798        else
1799                close(input_fd);
1800        free(objects);
1801        strbuf_release(&index_name_buf);
1802        strbuf_release(&keep_name_buf);
1803        if (pack_name == NULL)
1804                free((void *) curr_pack);
1805        if (index_name == NULL)
1806                free((void *) curr_index);
1807
1808        /*
1809         * Let the caller know this pack is not self contained
1810         */
1811        if (check_self_contained_and_connected && foreign_nr)
1812                return 1;
1813
1814        return 0;
1815}