builtin / index-pack.con commit read-cache: fix index corruption with index v4 (0b90b88)
   1#include "builtin.h"
   2#include "config.h"
   3#include "delta.h"
   4#include "pack.h"
   5#include "csum-file.h"
   6#include "blob.h"
   7#include "commit.h"
   8#include "tag.h"
   9#include "tree.h"
  10#include "progress.h"
  11#include "fsck.h"
  12#include "exec_cmd.h"
  13#include "streaming.h"
  14#include "thread-utils.h"
  15
  16static const char index_pack_usage[] =
  17"git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
  18
  19struct object_entry {
  20        struct pack_idx_entry idx;
  21        unsigned long size;
  22        unsigned char hdr_size;
  23        signed char type;
  24        signed char real_type;
  25};
  26
  27struct object_stat {
  28        unsigned delta_depth;
  29        int base_object_no;
  30};
  31
  32struct base_data {
  33        struct base_data *base;
  34        struct base_data *child;
  35        struct object_entry *obj;
  36        void *data;
  37        unsigned long size;
  38        int ref_first, ref_last;
  39        int ofs_first, ofs_last;
  40};
  41
  42struct thread_local {
  43#ifndef NO_PTHREADS
  44        pthread_t thread;
  45#endif
  46        struct base_data *base_cache;
  47        size_t base_cache_used;
  48        int pack_fd;
  49};
  50
  51#define FLAG_LINK (1u<<20)
  52#define FLAG_CHECKED (1u<<21)
  53
  54struct ofs_delta_entry {
  55        off_t offset;
  56        int obj_no;
  57};
  58
  59struct ref_delta_entry {
  60        unsigned char sha1[20];
  61        int obj_no;
  62};
  63
  64static struct object_entry *objects;
  65static struct object_stat *obj_stat;
  66static struct ofs_delta_entry *ofs_deltas;
  67static struct ref_delta_entry *ref_deltas;
  68static struct thread_local nothread_data;
  69static int nr_objects;
  70static int nr_ofs_deltas;
  71static int nr_ref_deltas;
  72static int ref_deltas_alloc;
  73static int nr_resolved_deltas;
  74static int nr_threads;
  75
  76static int from_stdin;
  77static int strict;
  78static int do_fsck_object;
  79static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
  80static int verbose;
  81static int show_resolving_progress;
  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 off_t max_input_size;
  92static unsigned deepest_delta;
  93static git_SHA_CTX input_ctx;
  94static uint32_t input_crc32;
  95static int input_fd, output_fd;
  96static const char *curr_pack;
  97
  98#ifndef NO_PTHREADS
  99
 100static struct thread_local *thread_data;
 101static int nr_dispatched;
 102static int threads_active;
 103
 104static pthread_mutex_t read_mutex;
 105#define read_lock()             lock_mutex(&read_mutex)
 106#define read_unlock()           unlock_mutex(&read_mutex)
 107
 108static pthread_mutex_t counter_mutex;
 109#define counter_lock()          lock_mutex(&counter_mutex)
 110#define counter_unlock()        unlock_mutex(&counter_mutex)
 111
 112static pthread_mutex_t work_mutex;
 113#define work_lock()             lock_mutex(&work_mutex)
 114#define work_unlock()           unlock_mutex(&work_mutex)
 115
 116static pthread_mutex_t deepest_delta_mutex;
 117#define deepest_delta_lock()    lock_mutex(&deepest_delta_mutex)
 118#define deepest_delta_unlock()  unlock_mutex(&deepest_delta_mutex)
 119
 120static pthread_mutex_t type_cas_mutex;
 121#define type_cas_lock()         lock_mutex(&type_cas_mutex)
 122#define type_cas_unlock()       unlock_mutex(&type_cas_mutex)
 123
 124static pthread_key_t key;
 125
 126static inline void lock_mutex(pthread_mutex_t *mutex)
 127{
 128        if (threads_active)
 129                pthread_mutex_lock(mutex);
 130}
 131
 132static inline void unlock_mutex(pthread_mutex_t *mutex)
 133{
 134        if (threads_active)
 135                pthread_mutex_unlock(mutex);
 136}
 137
 138/*
 139 * Mutex and conditional variable can't be statically-initialized on Windows.
 140 */
 141static void init_thread(void)
 142{
 143        int i;
 144        init_recursive_mutex(&read_mutex);
 145        pthread_mutex_init(&counter_mutex, NULL);
 146        pthread_mutex_init(&work_mutex, NULL);
 147        pthread_mutex_init(&type_cas_mutex, NULL);
 148        if (show_stat)
 149                pthread_mutex_init(&deepest_delta_mutex, NULL);
 150        pthread_key_create(&key, NULL);
 151        thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 152        for (i = 0; i < nr_threads; i++) {
 153                thread_data[i].pack_fd = open(curr_pack, O_RDONLY);
 154                if (thread_data[i].pack_fd == -1)
 155                        die_errno(_("unable to open %s"), curr_pack);
 156        }
 157
 158        threads_active = 1;
 159}
 160
 161static void cleanup_thread(void)
 162{
 163        int i;
 164        if (!threads_active)
 165                return;
 166        threads_active = 0;
 167        pthread_mutex_destroy(&read_mutex);
 168        pthread_mutex_destroy(&counter_mutex);
 169        pthread_mutex_destroy(&work_mutex);
 170        pthread_mutex_destroy(&type_cas_mutex);
 171        if (show_stat)
 172                pthread_mutex_destroy(&deepest_delta_mutex);
 173        for (i = 0; i < nr_threads; i++)
 174                close(thread_data[i].pack_fd);
 175        pthread_key_delete(key);
 176        free(thread_data);
 177}
 178
 179#else
 180
 181#define read_lock()
 182#define read_unlock()
 183
 184#define counter_lock()
 185#define counter_unlock()
 186
 187#define work_lock()
 188#define work_unlock()
 189
 190#define deepest_delta_lock()
 191#define deepest_delta_unlock()
 192
 193#define type_cas_lock()
 194#define type_cas_unlock()
 195
 196#endif
 197
 198
 199static int mark_link(struct object *obj, int type, void *data, struct fsck_options *options)
 200{
 201        if (!obj)
 202                return -1;
 203
 204        if (type != OBJ_ANY && obj->type != type)
 205                die(_("object type mismatch at %s"), oid_to_hex(&obj->oid));
 206
 207        obj->flags |= FLAG_LINK;
 208        return 0;
 209}
 210
 211/* The content of each linked object must have been checked
 212   or it must be already present in the object database */
 213static unsigned check_object(struct object *obj)
 214{
 215        if (!obj)
 216                return 0;
 217
 218        if (!(obj->flags & FLAG_LINK))
 219                return 0;
 220
 221        if (!(obj->flags & FLAG_CHECKED)) {
 222                unsigned long size;
 223                int type = sha1_object_info(obj->oid.hash, &size);
 224                if (type <= 0)
 225                        die(_("did not receive expected object %s"),
 226                              oid_to_hex(&obj->oid));
 227                if (type != obj->type)
 228                        die(_("object %s: expected type %s, found %s"),
 229                            oid_to_hex(&obj->oid),
 230                            typename(obj->type), typename(type));
 231                obj->flags |= FLAG_CHECKED;
 232                return 1;
 233        }
 234
 235        return 0;
 236}
 237
 238static unsigned check_objects(void)
 239{
 240        unsigned i, max, foreign_nr = 0;
 241
 242        max = get_max_object_index();
 243        for (i = 0; i < max; i++)
 244                foreign_nr += check_object(get_indexed_object(i));
 245        return foreign_nr;
 246}
 247
 248
 249/* Discard current buffer used content. */
 250static void flush(void)
 251{
 252        if (input_offset) {
 253                if (output_fd >= 0)
 254                        write_or_die(output_fd, input_buffer, input_offset);
 255                git_SHA1_Update(&input_ctx, input_buffer, input_offset);
 256                memmove(input_buffer, input_buffer + input_offset, input_len);
 257                input_offset = 0;
 258        }
 259}
 260
 261/*
 262 * Make sure at least "min" bytes are available in the buffer, and
 263 * return the pointer to the buffer.
 264 */
 265static void *fill(int min)
 266{
 267        if (min <= input_len)
 268                return input_buffer + input_offset;
 269        if (min > sizeof(input_buffer))
 270                die(Q_("cannot fill %d byte",
 271                       "cannot fill %d bytes",
 272                       min),
 273                    min);
 274        flush();
 275        do {
 276                ssize_t ret = xread(input_fd, input_buffer + input_len,
 277                                sizeof(input_buffer) - input_len);
 278                if (ret <= 0) {
 279                        if (!ret)
 280                                die(_("early EOF"));
 281                        die_errno(_("read error on input"));
 282                }
 283                input_len += ret;
 284                if (from_stdin)
 285                        display_throughput(progress, consumed_bytes + input_len);
 286        } while (input_len < min);
 287        return input_buffer;
 288}
 289
 290static void use(int bytes)
 291{
 292        if (bytes > input_len)
 293                die(_("used more bytes than were available"));
 294        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 295        input_len -= bytes;
 296        input_offset += bytes;
 297
 298        /* make sure off_t is sufficiently large not to wrap */
 299        if (signed_add_overflows(consumed_bytes, bytes))
 300                die(_("pack too large for current definition of off_t"));
 301        consumed_bytes += bytes;
 302        if (max_input_size && consumed_bytes > max_input_size)
 303                die(_("pack exceeds maximum allowed size"));
 304}
 305
 306static const char *open_pack_file(const char *pack_name)
 307{
 308        if (from_stdin) {
 309                input_fd = 0;
 310                if (!pack_name) {
 311                        struct strbuf tmp_file = STRBUF_INIT;
 312                        output_fd = odb_mkstemp(&tmp_file,
 313                                                "pack/tmp_pack_XXXXXX");
 314                        pack_name = strbuf_detach(&tmp_file, NULL);
 315                } else {
 316                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 317                        if (output_fd < 0)
 318                                die_errno(_("unable to create '%s'"), pack_name);
 319                }
 320                nothread_data.pack_fd = output_fd;
 321        } else {
 322                input_fd = open(pack_name, O_RDONLY);
 323                if (input_fd < 0)
 324                        die_errno(_("cannot open packfile '%s'"), pack_name);
 325                output_fd = -1;
 326                nothread_data.pack_fd = input_fd;
 327        }
 328        git_SHA1_Init(&input_ctx);
 329        return pack_name;
 330}
 331
 332static void parse_pack_header(void)
 333{
 334        struct pack_header *hdr = fill(sizeof(struct pack_header));
 335
 336        /* Header consistency check */
 337        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 338                die(_("pack signature mismatch"));
 339        if (!pack_version_ok(hdr->hdr_version))
 340                die(_("pack version %"PRIu32" unsupported"),
 341                        ntohl(hdr->hdr_version));
 342
 343        nr_objects = ntohl(hdr->hdr_entries);
 344        use(sizeof(struct pack_header));
 345}
 346
 347static NORETURN void bad_object(off_t offset, const char *format,
 348                       ...) __attribute__((format (printf, 2, 3)));
 349
 350static NORETURN void bad_object(off_t offset, const char *format, ...)
 351{
 352        va_list params;
 353        char buf[1024];
 354
 355        va_start(params, format);
 356        vsnprintf(buf, sizeof(buf), format, params);
 357        va_end(params);
 358        die(_("pack has bad object at offset %"PRIuMAX": %s"),
 359            (uintmax_t)offset, buf);
 360}
 361
 362static inline struct thread_local *get_thread_data(void)
 363{
 364#ifndef NO_PTHREADS
 365        if (threads_active)
 366                return pthread_getspecific(key);
 367        assert(!threads_active &&
 368               "This should only be reached when all threads are gone");
 369#endif
 370        return &nothread_data;
 371}
 372
 373#ifndef NO_PTHREADS
 374static void set_thread_data(struct thread_local *data)
 375{
 376        if (threads_active)
 377                pthread_setspecific(key, data);
 378}
 379#endif
 380
 381static struct base_data *alloc_base_data(void)
 382{
 383        struct base_data *base = xcalloc(1, sizeof(struct base_data));
 384        base->ref_last = -1;
 385        base->ofs_last = -1;
 386        return base;
 387}
 388
 389static void free_base_data(struct base_data *c)
 390{
 391        if (c->data) {
 392                FREE_AND_NULL(c->data);
 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_AND_NULL(data);
 609        }
 610        return data;
 611}
 612
 613static void *get_data_from_pack(struct object_entry *obj)
 614{
 615        return unpack_data(obj, NULL, NULL);
 616}
 617
 618static int compare_ofs_delta_bases(off_t offset1, off_t offset2,
 619                                   enum object_type type1,
 620                                   enum object_type type2)
 621{
 622        int cmp = type1 - type2;
 623        if (cmp)
 624                return cmp;
 625        return offset1 < offset2 ? -1 :
 626               offset1 > offset2 ?  1 :
 627               0;
 628}
 629
 630static int find_ofs_delta(const off_t offset, enum object_type type)
 631{
 632        int first = 0, last = nr_ofs_deltas;
 633
 634        while (first < last) {
 635                int next = (first + last) / 2;
 636                struct ofs_delta_entry *delta = &ofs_deltas[next];
 637                int cmp;
 638
 639                cmp = compare_ofs_delta_bases(offset, delta->offset,
 640                                              type, objects[delta->obj_no].type);
 641                if (!cmp)
 642                        return next;
 643                if (cmp < 0) {
 644                        last = next;
 645                        continue;
 646                }
 647                first = next+1;
 648        }
 649        return -first-1;
 650}
 651
 652static void find_ofs_delta_children(off_t offset,
 653                                    int *first_index, int *last_index,
 654                                    enum object_type type)
 655{
 656        int first = find_ofs_delta(offset, type);
 657        int last = first;
 658        int end = nr_ofs_deltas - 1;
 659
 660        if (first < 0) {
 661                *first_index = 0;
 662                *last_index = -1;
 663                return;
 664        }
 665        while (first > 0 && ofs_deltas[first - 1].offset == offset)
 666                --first;
 667        while (last < end && ofs_deltas[last + 1].offset == offset)
 668                ++last;
 669        *first_index = first;
 670        *last_index = last;
 671}
 672
 673static int compare_ref_delta_bases(const unsigned char *sha1,
 674                                   const unsigned char *sha2,
 675                                   enum object_type type1,
 676                                   enum object_type type2)
 677{
 678        int cmp = type1 - type2;
 679        if (cmp)
 680                return cmp;
 681        return hashcmp(sha1, sha2);
 682}
 683
 684static int find_ref_delta(const unsigned char *sha1, enum object_type type)
 685{
 686        int first = 0, last = nr_ref_deltas;
 687
 688        while (first < last) {
 689                int next = (first + last) / 2;
 690                struct ref_delta_entry *delta = &ref_deltas[next];
 691                int cmp;
 692
 693                cmp = compare_ref_delta_bases(sha1, delta->sha1,
 694                                              type, objects[delta->obj_no].type);
 695                if (!cmp)
 696                        return next;
 697                if (cmp < 0) {
 698                        last = next;
 699                        continue;
 700                }
 701                first = next+1;
 702        }
 703        return -first-1;
 704}
 705
 706static void find_ref_delta_children(const unsigned char *sha1,
 707                                    int *first_index, int *last_index,
 708                                    enum object_type type)
 709{
 710        int first = find_ref_delta(sha1, type);
 711        int last = first;
 712        int end = nr_ref_deltas - 1;
 713
 714        if (first < 0) {
 715                *first_index = 0;
 716                *last_index = -1;
 717                return;
 718        }
 719        while (first > 0 && !hashcmp(ref_deltas[first - 1].sha1, sha1))
 720                --first;
 721        while (last < end && !hashcmp(ref_deltas[last + 1].sha1, sha1))
 722                ++last;
 723        *first_index = first;
 724        *last_index = last;
 725}
 726
 727struct compare_data {
 728        struct object_entry *entry;
 729        struct git_istream *st;
 730        unsigned char *buf;
 731        unsigned long buf_size;
 732};
 733
 734static int compare_objects(const unsigned char *buf, unsigned long size,
 735                           void *cb_data)
 736{
 737        struct compare_data *data = cb_data;
 738
 739        if (data->buf_size < size) {
 740                free(data->buf);
 741                data->buf = xmalloc(size);
 742                data->buf_size = size;
 743        }
 744
 745        while (size) {
 746                ssize_t len = read_istream(data->st, data->buf, size);
 747                if (len == 0)
 748                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 749                            oid_to_hex(&data->entry->idx.oid));
 750                if (len < 0)
 751                        die(_("unable to read %s"),
 752                            oid_to_hex(&data->entry->idx.oid));
 753                if (memcmp(buf, data->buf, len))
 754                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 755                            oid_to_hex(&data->entry->idx.oid));
 756                size -= len;
 757                buf += len;
 758        }
 759        return 0;
 760}
 761
 762static int check_collison(struct object_entry *entry)
 763{
 764        struct compare_data data;
 765        enum object_type type;
 766        unsigned long size;
 767
 768        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 769                return -1;
 770
 771        memset(&data, 0, sizeof(data));
 772        data.entry = entry;
 773        data.st = open_istream(entry->idx.oid.hash, &type, &size, NULL);
 774        if (!data.st)
 775                return -1;
 776        if (size != entry->size || type != entry->type)
 777                die(_("SHA1 COLLISION FOUND WITH %s !"),
 778                    oid_to_hex(&entry->idx.oid));
 779        unpack_data(entry, compare_objects, &data);
 780        close_istream(data.st);
 781        free(data.buf);
 782        return 0;
 783}
 784
 785static void sha1_object(const void *data, struct object_entry *obj_entry,
 786                        unsigned long size, enum object_type type,
 787                        const struct object_id *oid)
 788{
 789        void *new_data = NULL;
 790        int collision_test_needed = 0;
 791
 792        assert(data || obj_entry);
 793
 794        if (startup_info->have_repository) {
 795                read_lock();
 796                collision_test_needed =
 797                        has_sha1_file_with_flags(oid->hash, OBJECT_INFO_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);
 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, type, size, buf,
 849                                                  &eaten);
 850                        if (!obj)
 851                                die(_("invalid %s"), typename(type));
 852                        if (do_fsck_object &&
 853                            fsck_object(obj, buf, size, &fsck_options))
 854                                die(_("Error in object"));
 855                        if (fsck_walk(obj, NULL, &fsck_options))
 856                                die(_("Not all child objects of %s are reachable"), oid_to_hex(&obj->oid));
 857
 858                        if (obj->type == OBJ_TREE) {
 859                                struct tree *item = (struct tree *) obj;
 860                                item->buffer = NULL;
 861                                obj->parsed = 0;
 862                        }
 863                        if (obj->type == OBJ_COMMIT) {
 864                                struct commit *commit = (struct commit *) obj;
 865                                if (detach_commit_buffer(commit, NULL) != data)
 866                                        die("BUG: parse_object_buffer transmogrified our buffer");
 867                        }
 868                        obj->flags |= FLAG_CHECKED;
 869                }
 870                read_unlock();
 871        }
 872
 873        free(new_data);
 874}
 875
 876/*
 877 * This function is part of find_unresolved_deltas(). There are two
 878 * walkers going in the opposite ways.
 879 *
 880 * The first one in find_unresolved_deltas() traverses down from
 881 * parent node to children, deflating nodes along the way. However,
 882 * memory for deflated nodes is limited by delta_base_cache_limit, so
 883 * at some point parent node's deflated content may be freed.
 884 *
 885 * The second walker is this function, which goes from current node up
 886 * to top parent if necessary to deflate the node. In normal
 887 * situation, its parent node would be already deflated, so it just
 888 * needs to apply delta.
 889 *
 890 * In the worst case scenario, parent node is no longer deflated because
 891 * we're running out of delta_base_cache_limit; we need to re-deflate
 892 * parents, possibly up to the top base.
 893 *
 894 * All deflated objects here are subject to be freed if we exceed
 895 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 896 * just need to make sure the last node is not freed.
 897 */
 898static void *get_base_data(struct base_data *c)
 899{
 900        if (!c->data) {
 901                struct object_entry *obj = c->obj;
 902                struct base_data **delta = NULL;
 903                int delta_nr = 0, delta_alloc = 0;
 904
 905                while (is_delta_type(c->obj->type) && !c->data) {
 906                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 907                        delta[delta_nr++] = c;
 908                        c = c->base;
 909                }
 910                if (!delta_nr) {
 911                        c->data = get_data_from_pack(obj);
 912                        c->size = obj->size;
 913                        get_thread_data()->base_cache_used += c->size;
 914                        prune_base_data(c);
 915                }
 916                for (; delta_nr > 0; delta_nr--) {
 917                        void *base, *raw;
 918                        c = delta[delta_nr - 1];
 919                        obj = c->obj;
 920                        base = get_base_data(c->base);
 921                        raw = get_data_from_pack(obj);
 922                        c->data = patch_delta(
 923                                base, c->base->size,
 924                                raw, obj->size,
 925                                &c->size);
 926                        free(raw);
 927                        if (!c->data)
 928                                bad_object(obj->idx.offset, _("failed to apply delta"));
 929                        get_thread_data()->base_cache_used += c->size;
 930                        prune_base_data(c);
 931                }
 932                free(delta);
 933        }
 934        return c->data;
 935}
 936
 937static void resolve_delta(struct object_entry *delta_obj,
 938                          struct base_data *base, struct base_data *result)
 939{
 940        void *base_data, *delta_data;
 941
 942        if (show_stat) {
 943                int i = delta_obj - objects;
 944                int j = base->obj - objects;
 945                obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 946                deepest_delta_lock();
 947                if (deepest_delta < obj_stat[i].delta_depth)
 948                        deepest_delta = obj_stat[i].delta_depth;
 949                deepest_delta_unlock();
 950                obj_stat[i].base_object_no = j;
 951        }
 952        delta_data = get_data_from_pack(delta_obj);
 953        base_data = get_base_data(base);
 954        result->obj = delta_obj;
 955        result->data = patch_delta(base_data, base->size,
 956                                   delta_data, delta_obj->size, &result->size);
 957        free(delta_data);
 958        if (!result->data)
 959                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 960        hash_sha1_file(result->data, result->size,
 961                       typename(delta_obj->real_type),
 962                       delta_obj->idx.oid.hash);
 963        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 964                    &delta_obj->idx.oid);
 965        counter_lock();
 966        nr_resolved_deltas++;
 967        counter_unlock();
 968}
 969
 970/*
 971 * Standard boolean compare-and-swap: atomically check whether "*type" is
 972 * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 973 * and return false.
 974 */
 975static int compare_and_swap_type(signed char *type,
 976                                 enum object_type want,
 977                                 enum object_type set)
 978{
 979        enum object_type old;
 980
 981        type_cas_lock();
 982        old = *type;
 983        if (old == want)
 984                *type = set;
 985        type_cas_unlock();
 986
 987        return old == want;
 988}
 989
 990static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 991                                                  struct base_data *prev_base)
 992{
 993        if (base->ref_last == -1 && base->ofs_last == -1) {
 994                find_ref_delta_children(base->obj->idx.oid.hash,
 995                                        &base->ref_first, &base->ref_last,
 996                                        OBJ_REF_DELTA);
 997
 998                find_ofs_delta_children(base->obj->idx.offset,
 999                                        &base->ofs_first, &base->ofs_last,
1000                                        OBJ_OFS_DELTA);
1001
1002                if (base->ref_last == -1 && base->ofs_last == -1) {
1003                        free(base->data);
1004                        return NULL;
1005                }
1006
1007                link_base_data(prev_base, base);
1008        }
1009
1010        if (base->ref_first <= base->ref_last) {
1011                struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
1012                struct base_data *result = alloc_base_data();
1013
1014                if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
1015                                           base->obj->real_type))
1016                        die("BUG: child->real_type != OBJ_REF_DELTA");
1017
1018                resolve_delta(child, base, result);
1019                if (base->ref_first == base->ref_last && base->ofs_last == -1)
1020                        free_base_data(base);
1021
1022                base->ref_first++;
1023                return result;
1024        }
1025
1026        if (base->ofs_first <= base->ofs_last) {
1027                struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
1028                struct base_data *result = alloc_base_data();
1029
1030                assert(child->real_type == OBJ_OFS_DELTA);
1031                child->real_type = base->obj->real_type;
1032                resolve_delta(child, base, result);
1033                if (base->ofs_first == base->ofs_last)
1034                        free_base_data(base);
1035
1036                base->ofs_first++;
1037                return result;
1038        }
1039
1040        unlink_base_data(base);
1041        return NULL;
1042}
1043
1044static void find_unresolved_deltas(struct base_data *base)
1045{
1046        struct base_data *new_base, *prev_base = NULL;
1047        for (;;) {
1048                new_base = find_unresolved_deltas_1(base, prev_base);
1049
1050                if (new_base) {
1051                        prev_base = base;
1052                        base = new_base;
1053                } else {
1054                        free(base);
1055                        base = prev_base;
1056                        if (!base)
1057                                return;
1058                        prev_base = base->base;
1059                }
1060        }
1061}
1062
1063static int compare_ofs_delta_entry(const void *a, const void *b)
1064{
1065        const struct ofs_delta_entry *delta_a = a;
1066        const struct ofs_delta_entry *delta_b = b;
1067
1068        return delta_a->offset < delta_b->offset ? -1 :
1069               delta_a->offset > delta_b->offset ?  1 :
1070               0;
1071}
1072
1073static int compare_ref_delta_entry(const void *a, const void *b)
1074{
1075        const struct ref_delta_entry *delta_a = a;
1076        const struct ref_delta_entry *delta_b = b;
1077
1078        return hashcmp(delta_a->sha1, delta_b->sha1);
1079}
1080
1081static void resolve_base(struct object_entry *obj)
1082{
1083        struct base_data *base_obj = alloc_base_data();
1084        base_obj->obj = obj;
1085        base_obj->data = NULL;
1086        find_unresolved_deltas(base_obj);
1087}
1088
1089#ifndef NO_PTHREADS
1090static void *threaded_second_pass(void *data)
1091{
1092        set_thread_data(data);
1093        for (;;) {
1094                int i;
1095                counter_lock();
1096                display_progress(progress, nr_resolved_deltas);
1097                counter_unlock();
1098                work_lock();
1099                while (nr_dispatched < nr_objects &&
1100                       is_delta_type(objects[nr_dispatched].type))
1101                        nr_dispatched++;
1102                if (nr_dispatched >= nr_objects) {
1103                        work_unlock();
1104                        break;
1105                }
1106                i = nr_dispatched++;
1107                work_unlock();
1108
1109                resolve_base(&objects[i]);
1110        }
1111        return NULL;
1112}
1113#endif
1114
1115/*
1116 * First pass:
1117 * - find locations of all objects;
1118 * - calculate SHA1 of all non-delta objects;
1119 * - remember base (SHA1 or offset) for all deltas.
1120 */
1121static void parse_pack_objects(unsigned char *sha1)
1122{
1123        int i, nr_delays = 0;
1124        struct ofs_delta_entry *ofs_delta = ofs_deltas;
1125        unsigned char ref_delta_sha1[20];
1126        struct stat st;
1127
1128        if (verbose)
1129                progress = start_progress(
1130                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1131                                nr_objects);
1132        for (i = 0; i < nr_objects; i++) {
1133                struct object_entry *obj = &objects[i];
1134                void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1135                                              ref_delta_sha1,
1136                                              obj->idx.oid.hash);
1137                obj->real_type = obj->type;
1138                if (obj->type == OBJ_OFS_DELTA) {
1139                        nr_ofs_deltas++;
1140                        ofs_delta->obj_no = i;
1141                        ofs_delta++;
1142                } else if (obj->type == OBJ_REF_DELTA) {
1143                        ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1144                        hashcpy(ref_deltas[nr_ref_deltas].sha1, ref_delta_sha1);
1145                        ref_deltas[nr_ref_deltas].obj_no = i;
1146                        nr_ref_deltas++;
1147                } else if (!data) {
1148                        /* large blobs, check later */
1149                        obj->real_type = OBJ_BAD;
1150                        nr_delays++;
1151                } else
1152                        sha1_object(data, NULL, obj->size, obj->type,
1153                                    &obj->idx.oid);
1154                free(data);
1155                display_progress(progress, i+1);
1156        }
1157        objects[i].idx.offset = consumed_bytes;
1158        stop_progress(&progress);
1159
1160        /* Check pack integrity */
1161        flush();
1162        git_SHA1_Final(sha1, &input_ctx);
1163        if (hashcmp(fill(20), sha1))
1164                die(_("pack is corrupted (SHA1 mismatch)"));
1165        use(20);
1166
1167        /* If input_fd is a file, we should have reached its end now. */
1168        if (fstat(input_fd, &st))
1169                die_errno(_("cannot fstat packfile"));
1170        if (S_ISREG(st.st_mode) &&
1171                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1172                die(_("pack has junk at the end"));
1173
1174        for (i = 0; i < nr_objects; i++) {
1175                struct object_entry *obj = &objects[i];
1176                if (obj->real_type != OBJ_BAD)
1177                        continue;
1178                obj->real_type = obj->type;
1179                sha1_object(NULL, obj, obj->size, obj->type,
1180                            &obj->idx.oid);
1181                nr_delays--;
1182        }
1183        if (nr_delays)
1184                die(_("confusion beyond insanity in parse_pack_objects()"));
1185}
1186
1187/*
1188 * Second pass:
1189 * - for all non-delta objects, look if it is used as a base for
1190 *   deltas;
1191 * - if used as a base, uncompress the object and apply all deltas,
1192 *   recursively checking if the resulting object is used as a base
1193 *   for some more deltas.
1194 */
1195static void resolve_deltas(void)
1196{
1197        int i;
1198
1199        if (!nr_ofs_deltas && !nr_ref_deltas)
1200                return;
1201
1202        /* Sort deltas by base SHA1/offset for fast searching */
1203        QSORT(ofs_deltas, nr_ofs_deltas, compare_ofs_delta_entry);
1204        QSORT(ref_deltas, nr_ref_deltas, compare_ref_delta_entry);
1205
1206        if (verbose || show_resolving_progress)
1207                progress = start_progress(_("Resolving deltas"),
1208                                          nr_ref_deltas + nr_ofs_deltas);
1209
1210#ifndef NO_PTHREADS
1211        nr_dispatched = 0;
1212        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1213                init_thread();
1214                for (i = 0; i < nr_threads; i++) {
1215                        int ret = pthread_create(&thread_data[i].thread, NULL,
1216                                                 threaded_second_pass, thread_data + i);
1217                        if (ret)
1218                                die(_("unable to create thread: %s"),
1219                                    strerror(ret));
1220                }
1221                for (i = 0; i < nr_threads; i++)
1222                        pthread_join(thread_data[i].thread, NULL);
1223                cleanup_thread();
1224                return;
1225        }
1226#endif
1227
1228        for (i = 0; i < nr_objects; i++) {
1229                struct object_entry *obj = &objects[i];
1230
1231                if (is_delta_type(obj->type))
1232                        continue;
1233                resolve_base(obj);
1234                display_progress(progress, nr_resolved_deltas);
1235        }
1236}
1237
1238/*
1239 * Third pass:
1240 * - append objects to convert thin pack to full pack if required
1241 * - write the final 20-byte SHA-1
1242 */
1243static void fix_unresolved_deltas(struct sha1file *f);
1244static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
1245{
1246        if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1247                stop_progress(&progress);
1248                /* Flush remaining pack final 20-byte SHA1. */
1249                flush();
1250                return;
1251        }
1252
1253        if (fix_thin_pack) {
1254                struct sha1file *f;
1255                unsigned char read_sha1[20], tail_sha1[20];
1256                struct strbuf msg = STRBUF_INIT;
1257                int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1258                int nr_objects_initial = nr_objects;
1259                if (nr_unresolved <= 0)
1260                        die(_("confusion beyond insanity"));
1261                REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1262                memset(objects + nr_objects + 1, 0,
1263                       nr_unresolved * sizeof(*objects));
1264                f = sha1fd(output_fd, curr_pack);
1265                fix_unresolved_deltas(f);
1266                strbuf_addf(&msg, Q_("completed with %d local object",
1267                                     "completed with %d local objects",
1268                                     nr_objects - nr_objects_initial),
1269                            nr_objects - nr_objects_initial);
1270                stop_progress_msg(&progress, msg.buf);
1271                strbuf_release(&msg);
1272                sha1close(f, tail_sha1, 0);
1273                hashcpy(read_sha1, pack_sha1);
1274                fixup_pack_header_footer(output_fd, pack_sha1,
1275                                         curr_pack, nr_objects,
1276                                         read_sha1, consumed_bytes-20);
1277                if (hashcmp(read_sha1, tail_sha1) != 0)
1278                        die(_("Unexpected tail checksum for %s "
1279                              "(disk corruption?)"), curr_pack);
1280        }
1281        if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1282                die(Q_("pack has %d unresolved delta",
1283                       "pack has %d unresolved deltas",
1284                       nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1285                    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1286}
1287
1288static int write_compressed(struct sha1file *f, void *in, unsigned int size)
1289{
1290        git_zstream stream;
1291        int status;
1292        unsigned char outbuf[4096];
1293
1294        git_deflate_init(&stream, zlib_compression_level);
1295        stream.next_in = in;
1296        stream.avail_in = size;
1297
1298        do {
1299                stream.next_out = outbuf;
1300                stream.avail_out = sizeof(outbuf);
1301                status = git_deflate(&stream, Z_FINISH);
1302                sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
1303        } while (status == Z_OK);
1304
1305        if (status != Z_STREAM_END)
1306                die(_("unable to deflate appended object (%d)"), status);
1307        size = stream.total_out;
1308        git_deflate_end(&stream);
1309        return size;
1310}
1311
1312static struct object_entry *append_obj_to_pack(struct sha1file *f,
1313                               const unsigned char *sha1, void *buf,
1314                               unsigned long size, enum object_type type)
1315{
1316        struct object_entry *obj = &objects[nr_objects++];
1317        unsigned char header[10];
1318        unsigned long s = size;
1319        int n = 0;
1320        unsigned char c = (type << 4) | (s & 15);
1321        s >>= 4;
1322        while (s) {
1323                header[n++] = c | 0x80;
1324                c = s & 0x7f;
1325                s >>= 7;
1326        }
1327        header[n++] = c;
1328        crc32_begin(f);
1329        sha1write(f, header, n);
1330        obj[0].size = size;
1331        obj[0].hdr_size = n;
1332        obj[0].type = type;
1333        obj[0].real_type = type;
1334        obj[1].idx.offset = obj[0].idx.offset + n;
1335        obj[1].idx.offset += write_compressed(f, buf, size);
1336        obj[0].idx.crc32 = crc32_end(f);
1337        sha1flush(f);
1338        hashcpy(obj->idx.oid.hash, sha1);
1339        return obj;
1340}
1341
1342static int delta_pos_compare(const void *_a, const void *_b)
1343{
1344        struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1345        struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1346        return a->obj_no - b->obj_no;
1347}
1348
1349static void fix_unresolved_deltas(struct sha1file *f)
1350{
1351        struct ref_delta_entry **sorted_by_pos;
1352        int i;
1353
1354        /*
1355         * Since many unresolved deltas may well be themselves base objects
1356         * for more unresolved deltas, we really want to include the
1357         * smallest number of base objects that would cover as much delta
1358         * as possible by picking the
1359         * trunc deltas first, allowing for other deltas to resolve without
1360         * additional base objects.  Since most base objects are to be found
1361         * before deltas depending on them, a good heuristic is to start
1362         * resolving deltas in the same order as their position in the pack.
1363         */
1364        ALLOC_ARRAY(sorted_by_pos, nr_ref_deltas);
1365        for (i = 0; i < nr_ref_deltas; i++)
1366                sorted_by_pos[i] = &ref_deltas[i];
1367        QSORT(sorted_by_pos, nr_ref_deltas, delta_pos_compare);
1368
1369        for (i = 0; i < nr_ref_deltas; i++) {
1370                struct ref_delta_entry *d = sorted_by_pos[i];
1371                enum object_type type;
1372                struct base_data *base_obj = alloc_base_data();
1373
1374                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1375                        continue;
1376                base_obj->data = read_sha1_file(d->sha1, &type, &base_obj->size);
1377                if (!base_obj->data)
1378                        continue;
1379
1380                if (check_sha1_signature(d->sha1, base_obj->data,
1381                                base_obj->size, typename(type)))
1382                        die(_("local object %s is corrupt"), sha1_to_hex(d->sha1));
1383                base_obj->obj = append_obj_to_pack(f, d->sha1,
1384                                        base_obj->data, base_obj->size, type);
1385                find_unresolved_deltas(base_obj);
1386                display_progress(progress, nr_resolved_deltas);
1387        }
1388        free(sorted_by_pos);
1389}
1390
1391static void final(const char *final_pack_name, const char *curr_pack_name,
1392                  const char *final_index_name, const char *curr_index_name,
1393                  const char *keep_name, const char *keep_msg,
1394                  unsigned char *sha1)
1395{
1396        const char *report = "pack";
1397        struct strbuf pack_name = STRBUF_INIT;
1398        struct strbuf index_name = STRBUF_INIT;
1399        struct strbuf keep_name_buf = STRBUF_INIT;
1400        int err;
1401
1402        if (!from_stdin) {
1403                close(input_fd);
1404        } else {
1405                fsync_or_die(output_fd, curr_pack_name);
1406                err = close(output_fd);
1407                if (err)
1408                        die_errno(_("error while closing pack file"));
1409        }
1410
1411        if (keep_msg) {
1412                int keep_fd, keep_msg_len = strlen(keep_msg);
1413
1414                if (!keep_name)
1415                        keep_name = odb_pack_name(&keep_name_buf, sha1, "keep");
1416
1417                keep_fd = odb_pack_keep(keep_name);
1418                if (keep_fd < 0) {
1419                        if (errno != EEXIST)
1420                                die_errno(_("cannot write keep file '%s'"),
1421                                          keep_name);
1422                } else {
1423                        if (keep_msg_len > 0) {
1424                                write_or_die(keep_fd, keep_msg, keep_msg_len);
1425                                write_or_die(keep_fd, "\n", 1);
1426                        }
1427                        if (close(keep_fd) != 0)
1428                                die_errno(_("cannot close written keep file '%s'"),
1429                                          keep_name);
1430                        report = "keep";
1431                }
1432        }
1433
1434        if (final_pack_name != curr_pack_name) {
1435                if (!final_pack_name)
1436                        final_pack_name = odb_pack_name(&pack_name, sha1, "pack");
1437                if (finalize_object_file(curr_pack_name, final_pack_name))
1438                        die(_("cannot store pack file"));
1439        } else if (from_stdin)
1440                chmod(final_pack_name, 0444);
1441
1442        if (final_index_name != curr_index_name) {
1443                if (!final_index_name)
1444                        final_index_name = odb_pack_name(&index_name, sha1, "idx");
1445                if (finalize_object_file(curr_index_name, final_index_name))
1446                        die(_("cannot store index file"));
1447        } else
1448                chmod(final_index_name, 0444);
1449
1450        if (!from_stdin) {
1451                printf("%s\n", sha1_to_hex(sha1));
1452        } else {
1453                struct strbuf buf = STRBUF_INIT;
1454
1455                strbuf_addf(&buf, "%s\t%s\n", report, sha1_to_hex(sha1));
1456                write_or_die(1, buf.buf, buf.len);
1457                strbuf_release(&buf);
1458
1459                /*
1460                 * Let's just mimic git-unpack-objects here and write
1461                 * the last part of the input buffer to stdout.
1462                 */
1463                while (input_len) {
1464                        err = xwrite(1, input_buffer + input_offset, input_len);
1465                        if (err <= 0)
1466                                break;
1467                        input_len -= err;
1468                        input_offset += err;
1469                }
1470        }
1471
1472        strbuf_release(&index_name);
1473        strbuf_release(&pack_name);
1474        strbuf_release(&keep_name_buf);
1475}
1476
1477static int git_index_pack_config(const char *k, const char *v, void *cb)
1478{
1479        struct pack_idx_option *opts = cb;
1480
1481        if (!strcmp(k, "pack.indexversion")) {
1482                opts->version = git_config_int(k, v);
1483                if (opts->version > 2)
1484                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1485                return 0;
1486        }
1487        if (!strcmp(k, "pack.threads")) {
1488                nr_threads = git_config_int(k, v);
1489                if (nr_threads < 0)
1490                        die(_("invalid number of threads specified (%d)"),
1491                            nr_threads);
1492#ifdef NO_PTHREADS
1493                if (nr_threads != 1)
1494                        warning(_("no threads support, ignoring %s"), k);
1495                nr_threads = 1;
1496#endif
1497                return 0;
1498        }
1499        return git_default_config(k, v, cb);
1500}
1501
1502static int cmp_uint32(const void *a_, const void *b_)
1503{
1504        uint32_t a = *((uint32_t *)a_);
1505        uint32_t b = *((uint32_t *)b_);
1506
1507        return (a < b) ? -1 : (a != b);
1508}
1509
1510static void read_v2_anomalous_offsets(struct packed_git *p,
1511                                      struct pack_idx_option *opts)
1512{
1513        const uint32_t *idx1, *idx2;
1514        uint32_t i;
1515
1516        /* The address of the 4-byte offset table */
1517        idx1 = (((const uint32_t *)p->index_data)
1518                + 2 /* 8-byte header */
1519                + 256 /* fan out */
1520                + 5 * p->num_objects /* 20-byte SHA-1 table */
1521                + p->num_objects /* CRC32 table */
1522                );
1523
1524        /* The address of the 8-byte offset table */
1525        idx2 = idx1 + p->num_objects;
1526
1527        for (i = 0; i < p->num_objects; i++) {
1528                uint32_t off = ntohl(idx1[i]);
1529                if (!(off & 0x80000000))
1530                        continue;
1531                off = off & 0x7fffffff;
1532                check_pack_index_ptr(p, &idx2[off * 2]);
1533                if (idx2[off * 2])
1534                        continue;
1535                /*
1536                 * The real offset is ntohl(idx2[off * 2]) in high 4
1537                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1538                 * octets.  But idx2[off * 2] is Zero!!!
1539                 */
1540                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1541                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1542        }
1543
1544        QSORT(opts->anomaly, opts->anomaly_nr, cmp_uint32);
1545}
1546
1547static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1548{
1549        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1550
1551        if (!p)
1552                die(_("Cannot open existing pack file '%s'"), pack_name);
1553        if (open_pack_index(p))
1554                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1555
1556        /* Read the attributes from the existing idx file */
1557        opts->version = p->index_version;
1558
1559        if (opts->version == 2)
1560                read_v2_anomalous_offsets(p, opts);
1561
1562        /*
1563         * Get rid of the idx file as we do not need it anymore.
1564         * NEEDSWORK: extract this bit from free_pack_by_name() in
1565         * sha1_file.c, perhaps?  It shouldn't matter very much as we
1566         * know we haven't installed this pack (hence we never have
1567         * read anything from it).
1568         */
1569        close_pack_index(p);
1570        free(p);
1571}
1572
1573static void show_pack_info(int stat_only)
1574{
1575        int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1576        unsigned long *chain_histogram = NULL;
1577
1578        if (deepest_delta)
1579                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1580
1581        for (i = 0; i < nr_objects; i++) {
1582                struct object_entry *obj = &objects[i];
1583
1584                if (is_delta_type(obj->type))
1585                        chain_histogram[obj_stat[i].delta_depth - 1]++;
1586                if (stat_only)
1587                        continue;
1588                printf("%s %-6s %lu %lu %"PRIuMAX,
1589                       oid_to_hex(&obj->idx.oid),
1590                       typename(obj->real_type), obj->size,
1591                       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1592                       (uintmax_t)obj->idx.offset);
1593                if (is_delta_type(obj->type)) {
1594                        struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1595                        printf(" %u %s", obj_stat[i].delta_depth,
1596                               oid_to_hex(&bobj->idx.oid));
1597                }
1598                putchar('\n');
1599        }
1600
1601        if (baseobjects)
1602                printf_ln(Q_("non delta: %d object",
1603                             "non delta: %d objects",
1604                             baseobjects),
1605                          baseobjects);
1606        for (i = 0; i < deepest_delta; i++) {
1607                if (!chain_histogram[i])
1608                        continue;
1609                printf_ln(Q_("chain length = %d: %lu object",
1610                             "chain length = %d: %lu objects",
1611                             chain_histogram[i]),
1612                          i + 1,
1613                          chain_histogram[i]);
1614        }
1615}
1616
1617static const char *derive_filename(const char *pack_name, const char *suffix,
1618                                   struct strbuf *buf)
1619{
1620        size_t len;
1621        if (!strip_suffix(pack_name, ".pack", &len))
1622                die(_("packfile name '%s' does not end with '.pack'"),
1623                    pack_name);
1624        strbuf_add(buf, pack_name, len);
1625        strbuf_addstr(buf, suffix);
1626        return buf->buf;
1627}
1628
1629int cmd_index_pack(int argc, const char **argv, const char *prefix)
1630{
1631        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1632        const char *curr_index;
1633        const char *index_name = NULL, *pack_name = NULL;
1634        const char *keep_name = NULL, *keep_msg = NULL;
1635        struct strbuf index_name_buf = STRBUF_INIT,
1636                      keep_name_buf = STRBUF_INIT;
1637        struct pack_idx_entry **idx_objects;
1638        struct pack_idx_option opts;
1639        unsigned char pack_sha1[20];
1640        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1641        int report_end_of_input = 0;
1642
1643        if (argc == 2 && !strcmp(argv[1], "-h"))
1644                usage(index_pack_usage);
1645
1646        check_replace_refs = 0;
1647        fsck_options.walk = mark_link;
1648
1649        reset_pack_idx_option(&opts);
1650        git_config(git_index_pack_config, &opts);
1651        if (prefix && chdir(prefix))
1652                die(_("Cannot come back to cwd"));
1653
1654        for (i = 1; i < argc; i++) {
1655                const char *arg = argv[i];
1656
1657                if (*arg == '-') {
1658                        if (!strcmp(arg, "--stdin")) {
1659                                from_stdin = 1;
1660                        } else if (!strcmp(arg, "--fix-thin")) {
1661                                fix_thin_pack = 1;
1662                        } else if (!strcmp(arg, "--strict")) {
1663                                strict = 1;
1664                                do_fsck_object = 1;
1665                        } else if (skip_prefix(arg, "--strict=", &arg)) {
1666                                strict = 1;
1667                                do_fsck_object = 1;
1668                                fsck_set_msg_types(&fsck_options, arg);
1669                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1670                                strict = 1;
1671                                check_self_contained_and_connected = 1;
1672                        } else if (!strcmp(arg, "--verify")) {
1673                                verify = 1;
1674                        } else if (!strcmp(arg, "--verify-stat")) {
1675                                verify = 1;
1676                                show_stat = 1;
1677                        } else if (!strcmp(arg, "--verify-stat-only")) {
1678                                verify = 1;
1679                                show_stat = 1;
1680                                stat_only = 1;
1681                        } else if (!strcmp(arg, "--keep")) {
1682                                keep_msg = "";
1683                        } else if (starts_with(arg, "--keep=")) {
1684                                keep_msg = arg + 7;
1685                        } else if (starts_with(arg, "--threads=")) {
1686                                char *end;
1687                                nr_threads = strtoul(arg+10, &end, 0);
1688                                if (!arg[10] || *end || nr_threads < 0)
1689                                        usage(index_pack_usage);
1690#ifdef NO_PTHREADS
1691                                if (nr_threads != 1)
1692                                        warning(_("no threads support, "
1693                                                  "ignoring %s"), arg);
1694                                nr_threads = 1;
1695#endif
1696                        } else if (starts_with(arg, "--pack_header=")) {
1697                                struct pack_header *hdr;
1698                                char *c;
1699
1700                                hdr = (struct pack_header *)input_buffer;
1701                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1702                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1703                                if (*c != ',')
1704                                        die(_("bad %s"), arg);
1705                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1706                                if (*c)
1707                                        die(_("bad %s"), arg);
1708                                input_len = sizeof(*hdr);
1709                        } else if (!strcmp(arg, "-v")) {
1710                                verbose = 1;
1711                        } else if (!strcmp(arg, "--show-resolving-progress")) {
1712                                show_resolving_progress = 1;
1713                        } else if (!strcmp(arg, "--report-end-of-input")) {
1714                                report_end_of_input = 1;
1715                        } else if (!strcmp(arg, "-o")) {
1716                                if (index_name || (i+1) >= argc)
1717                                        usage(index_pack_usage);
1718                                index_name = argv[++i];
1719                        } else if (starts_with(arg, "--index-version=")) {
1720                                char *c;
1721                                opts.version = strtoul(arg + 16, &c, 10);
1722                                if (opts.version > 2)
1723                                        die(_("bad %s"), arg);
1724                                if (*c == ',')
1725                                        opts.off32_limit = strtoul(c+1, &c, 0);
1726                                if (*c || opts.off32_limit & 0x80000000)
1727                                        die(_("bad %s"), arg);
1728                        } else if (skip_prefix(arg, "--max-input-size=", &arg)) {
1729                                max_input_size = strtoumax(arg, NULL, 10);
1730                        } else
1731                                usage(index_pack_usage);
1732                        continue;
1733                }
1734
1735                if (pack_name)
1736                        usage(index_pack_usage);
1737                pack_name = arg;
1738        }
1739
1740        if (!pack_name && !from_stdin)
1741                usage(index_pack_usage);
1742        if (fix_thin_pack && !from_stdin)
1743                die(_("--fix-thin cannot be used without --stdin"));
1744        if (from_stdin && !startup_info->have_repository)
1745                die(_("--stdin requires a git repository"));
1746        if (!index_name && pack_name)
1747                index_name = derive_filename(pack_name, ".idx", &index_name_buf);
1748        if (keep_msg && !keep_name && pack_name)
1749                keep_name = derive_filename(pack_name, ".keep", &keep_name_buf);
1750
1751        if (verify) {
1752                if (!index_name)
1753                        die(_("--verify with no packfile name given"));
1754                read_idx_option(&opts, index_name);
1755                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1756        }
1757        if (strict)
1758                opts.flags |= WRITE_IDX_STRICT;
1759
1760#ifndef NO_PTHREADS
1761        if (!nr_threads) {
1762                nr_threads = online_cpus();
1763                /* An experiment showed that more threads does not mean faster */
1764                if (nr_threads > 3)
1765                        nr_threads = 3;
1766        }
1767#endif
1768
1769        curr_pack = open_pack_file(pack_name);
1770        parse_pack_header();
1771        objects = xcalloc(st_add(nr_objects, 1), sizeof(struct object_entry));
1772        if (show_stat)
1773                obj_stat = xcalloc(st_add(nr_objects, 1), sizeof(struct object_stat));
1774        ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
1775        parse_pack_objects(pack_sha1);
1776        if (report_end_of_input)
1777                write_in_full(2, "\0", 1);
1778        resolve_deltas();
1779        conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1780        free(ofs_deltas);
1781        free(ref_deltas);
1782        if (strict)
1783                foreign_nr = check_objects();
1784
1785        if (show_stat)
1786                show_pack_info(stat_only);
1787
1788        ALLOC_ARRAY(idx_objects, nr_objects);
1789        for (i = 0; i < nr_objects; i++)
1790                idx_objects[i] = &objects[i].idx;
1791        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1792        free(idx_objects);
1793
1794        if (!verify)
1795                final(pack_name, curr_pack,
1796                      index_name, curr_index,
1797                      keep_name, keep_msg,
1798                      pack_sha1);
1799        else
1800                close(input_fd);
1801        free(objects);
1802        strbuf_release(&index_name_buf);
1803        strbuf_release(&keep_name_buf);
1804        if (pack_name == NULL)
1805                free((void *) curr_pack);
1806        if (index_name == NULL)
1807                free((void *) curr_index);
1808
1809        /*
1810         * Let the caller know this pack is not self contained
1811         */
1812        if (check_self_contained_and_connected && foreign_nr)
1813                return 1;
1814
1815        return 0;
1816}