builtin / index-pack.con commit t3200: verify "branch --list" sanity when rebasing from detached HEAD (1f537be)
   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#include "packfile.h"
  16
  17static const char index_pack_usage[] =
  18"git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
  19
  20struct object_entry {
  21        struct pack_idx_entry idx;
  22        unsigned long size;
  23        unsigned char hdr_size;
  24        signed char type;
  25        signed char real_type;
  26};
  27
  28struct object_stat {
  29        unsigned delta_depth;
  30        int base_object_no;
  31};
  32
  33struct base_data {
  34        struct base_data *base;
  35        struct base_data *child;
  36        struct object_entry *obj;
  37        void *data;
  38        unsigned long size;
  39        int ref_first, ref_last;
  40        int ofs_first, ofs_last;
  41};
  42
  43struct thread_local {
  44#ifndef NO_PTHREADS
  45        pthread_t thread;
  46#endif
  47        struct base_data *base_cache;
  48        size_t base_cache_used;
  49        int pack_fd;
  50};
  51
  52/* Remember to update object flag allocation in object.h */
  53#define FLAG_LINK (1u<<20)
  54#define FLAG_CHECKED (1u<<21)
  55
  56struct ofs_delta_entry {
  57        off_t offset;
  58        int obj_no;
  59};
  60
  61struct ref_delta_entry {
  62        unsigned char sha1[20];
  63        int obj_no;
  64};
  65
  66static struct object_entry *objects;
  67static struct object_stat *obj_stat;
  68static struct ofs_delta_entry *ofs_deltas;
  69static struct ref_delta_entry *ref_deltas;
  70static struct thread_local nothread_data;
  71static int nr_objects;
  72static int nr_ofs_deltas;
  73static int nr_ref_deltas;
  74static int ref_deltas_alloc;
  75static int nr_resolved_deltas;
  76static int nr_threads;
  77
  78static int from_stdin;
  79static int strict;
  80static int do_fsck_object;
  81static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
  82static int verbose;
  83static int show_resolving_progress;
  84static int show_stat;
  85static int check_self_contained_and_connected;
  86
  87static struct progress *progress;
  88
  89/* We always read in 4kB chunks. */
  90static unsigned char input_buffer[4096];
  91static unsigned int input_offset, input_len;
  92static off_t consumed_bytes;
  93static off_t max_input_size;
  94static unsigned deepest_delta;
  95static git_hash_ctx input_ctx;
  96static uint32_t input_crc32;
  97static int input_fd, output_fd;
  98static const char *curr_pack;
  99
 100#ifndef NO_PTHREADS
 101
 102static struct thread_local *thread_data;
 103static int nr_dispatched;
 104static int threads_active;
 105
 106static pthread_mutex_t read_mutex;
 107#define read_lock()             lock_mutex(&read_mutex)
 108#define read_unlock()           unlock_mutex(&read_mutex)
 109
 110static pthread_mutex_t counter_mutex;
 111#define counter_lock()          lock_mutex(&counter_mutex)
 112#define counter_unlock()        unlock_mutex(&counter_mutex)
 113
 114static pthread_mutex_t work_mutex;
 115#define work_lock()             lock_mutex(&work_mutex)
 116#define work_unlock()           unlock_mutex(&work_mutex)
 117
 118static pthread_mutex_t deepest_delta_mutex;
 119#define deepest_delta_lock()    lock_mutex(&deepest_delta_mutex)
 120#define deepest_delta_unlock()  unlock_mutex(&deepest_delta_mutex)
 121
 122static pthread_mutex_t type_cas_mutex;
 123#define type_cas_lock()         lock_mutex(&type_cas_mutex)
 124#define type_cas_unlock()       unlock_mutex(&type_cas_mutex)
 125
 126static pthread_key_t key;
 127
 128static inline void lock_mutex(pthread_mutex_t *mutex)
 129{
 130        if (threads_active)
 131                pthread_mutex_lock(mutex);
 132}
 133
 134static inline void unlock_mutex(pthread_mutex_t *mutex)
 135{
 136        if (threads_active)
 137                pthread_mutex_unlock(mutex);
 138}
 139
 140/*
 141 * Mutex and conditional variable can't be statically-initialized on Windows.
 142 */
 143static void init_thread(void)
 144{
 145        int i;
 146        init_recursive_mutex(&read_mutex);
 147        pthread_mutex_init(&counter_mutex, NULL);
 148        pthread_mutex_init(&work_mutex, NULL);
 149        pthread_mutex_init(&type_cas_mutex, NULL);
 150        if (show_stat)
 151                pthread_mutex_init(&deepest_delta_mutex, NULL);
 152        pthread_key_create(&key, NULL);
 153        thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 154        for (i = 0; i < nr_threads; i++) {
 155                thread_data[i].pack_fd = open(curr_pack, O_RDONLY);
 156                if (thread_data[i].pack_fd == -1)
 157                        die_errno(_("unable to open %s"), curr_pack);
 158        }
 159
 160        threads_active = 1;
 161}
 162
 163static void cleanup_thread(void)
 164{
 165        int i;
 166        if (!threads_active)
 167                return;
 168        threads_active = 0;
 169        pthread_mutex_destroy(&read_mutex);
 170        pthread_mutex_destroy(&counter_mutex);
 171        pthread_mutex_destroy(&work_mutex);
 172        pthread_mutex_destroy(&type_cas_mutex);
 173        if (show_stat)
 174                pthread_mutex_destroy(&deepest_delta_mutex);
 175        for (i = 0; i < nr_threads; i++)
 176                close(thread_data[i].pack_fd);
 177        pthread_key_delete(key);
 178        free(thread_data);
 179}
 180
 181#else
 182
 183#define read_lock()
 184#define read_unlock()
 185
 186#define counter_lock()
 187#define counter_unlock()
 188
 189#define work_lock()
 190#define work_unlock()
 191
 192#define deepest_delta_lock()
 193#define deepest_delta_unlock()
 194
 195#define type_cas_lock()
 196#define type_cas_unlock()
 197
 198#endif
 199
 200
 201static int mark_link(struct object *obj, int type, void *data, struct fsck_options *options)
 202{
 203        if (!obj)
 204                return -1;
 205
 206        if (type != OBJ_ANY && obj->type != type)
 207                die(_("object type mismatch at %s"), oid_to_hex(&obj->oid));
 208
 209        obj->flags |= FLAG_LINK;
 210        return 0;
 211}
 212
 213/* The content of each linked object must have been checked
 214   or it must be already present in the object database */
 215static unsigned check_object(struct object *obj)
 216{
 217        if (!obj)
 218                return 0;
 219
 220        if (!(obj->flags & FLAG_LINK))
 221                return 0;
 222
 223        if (!(obj->flags & FLAG_CHECKED)) {
 224                unsigned long size;
 225                int type = sha1_object_info(obj->oid.hash, &size);
 226                if (type <= 0)
 227                        die(_("did not receive expected object %s"),
 228                              oid_to_hex(&obj->oid));
 229                if (type != obj->type)
 230                        die(_("object %s: expected type %s, found %s"),
 231                            oid_to_hex(&obj->oid),
 232                            type_name(obj->type), type_name(type));
 233                obj->flags |= FLAG_CHECKED;
 234                return 1;
 235        }
 236
 237        return 0;
 238}
 239
 240static unsigned check_objects(void)
 241{
 242        unsigned i, max, foreign_nr = 0;
 243
 244        max = get_max_object_index();
 245        for (i = 0; i < max; i++)
 246                foreign_nr += check_object(get_indexed_object(i));
 247        return foreign_nr;
 248}
 249
 250
 251/* Discard current buffer used content. */
 252static void flush(void)
 253{
 254        if (input_offset) {
 255                if (output_fd >= 0)
 256                        write_or_die(output_fd, input_buffer, input_offset);
 257                the_hash_algo->update_fn(&input_ctx, input_buffer, input_offset);
 258                memmove(input_buffer, input_buffer + input_offset, input_len);
 259                input_offset = 0;
 260        }
 261}
 262
 263/*
 264 * Make sure at least "min" bytes are available in the buffer, and
 265 * return the pointer to the buffer.
 266 */
 267static void *fill(int min)
 268{
 269        if (min <= input_len)
 270                return input_buffer + input_offset;
 271        if (min > sizeof(input_buffer))
 272                die(Q_("cannot fill %d byte",
 273                       "cannot fill %d bytes",
 274                       min),
 275                    min);
 276        flush();
 277        do {
 278                ssize_t ret = xread(input_fd, input_buffer + input_len,
 279                                sizeof(input_buffer) - input_len);
 280                if (ret <= 0) {
 281                        if (!ret)
 282                                die(_("early EOF"));
 283                        die_errno(_("read error on input"));
 284                }
 285                input_len += ret;
 286                if (from_stdin)
 287                        display_throughput(progress, consumed_bytes + input_len);
 288        } while (input_len < min);
 289        return input_buffer;
 290}
 291
 292static void use(int bytes)
 293{
 294        if (bytes > input_len)
 295                die(_("used more bytes than were available"));
 296        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 297        input_len -= bytes;
 298        input_offset += bytes;
 299
 300        /* make sure off_t is sufficiently large not to wrap */
 301        if (signed_add_overflows(consumed_bytes, bytes))
 302                die(_("pack too large for current definition of off_t"));
 303        consumed_bytes += bytes;
 304        if (max_input_size && consumed_bytes > max_input_size)
 305                die(_("pack exceeds maximum allowed size"));
 306}
 307
 308static const char *open_pack_file(const char *pack_name)
 309{
 310        if (from_stdin) {
 311                input_fd = 0;
 312                if (!pack_name) {
 313                        struct strbuf tmp_file = STRBUF_INIT;
 314                        output_fd = odb_mkstemp(&tmp_file,
 315                                                "pack/tmp_pack_XXXXXX");
 316                        pack_name = strbuf_detach(&tmp_file, NULL);
 317                } else {
 318                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 319                        if (output_fd < 0)
 320                                die_errno(_("unable to create '%s'"), pack_name);
 321                }
 322                nothread_data.pack_fd = output_fd;
 323        } else {
 324                input_fd = open(pack_name, O_RDONLY);
 325                if (input_fd < 0)
 326                        die_errno(_("cannot open packfile '%s'"), pack_name);
 327                output_fd = -1;
 328                nothread_data.pack_fd = input_fd;
 329        }
 330        the_hash_algo->init_fn(&input_ctx);
 331        return pack_name;
 332}
 333
 334static void parse_pack_header(void)
 335{
 336        struct pack_header *hdr = fill(sizeof(struct pack_header));
 337
 338        /* Header consistency check */
 339        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 340                die(_("pack signature mismatch"));
 341        if (!pack_version_ok(hdr->hdr_version))
 342                die(_("pack version %"PRIu32" unsupported"),
 343                        ntohl(hdr->hdr_version));
 344
 345        nr_objects = ntohl(hdr->hdr_entries);
 346        use(sizeof(struct pack_header));
 347}
 348
 349static NORETURN void bad_object(off_t offset, const char *format,
 350                       ...) __attribute__((format (printf, 2, 3)));
 351
 352static NORETURN void bad_object(off_t offset, const char *format, ...)
 353{
 354        va_list params;
 355        char buf[1024];
 356
 357        va_start(params, format);
 358        vsnprintf(buf, sizeof(buf), format, params);
 359        va_end(params);
 360        die(_("pack has bad object at offset %"PRIuMAX": %s"),
 361            (uintmax_t)offset, buf);
 362}
 363
 364static inline struct thread_local *get_thread_data(void)
 365{
 366#ifndef NO_PTHREADS
 367        if (threads_active)
 368                return pthread_getspecific(key);
 369        assert(!threads_active &&
 370               "This should only be reached when all threads are gone");
 371#endif
 372        return &nothread_data;
 373}
 374
 375#ifndef NO_PTHREADS
 376static void set_thread_data(struct thread_local *data)
 377{
 378        if (threads_active)
 379                pthread_setspecific(key, data);
 380}
 381#endif
 382
 383static struct base_data *alloc_base_data(void)
 384{
 385        struct base_data *base = xcalloc(1, sizeof(struct base_data));
 386        base->ref_last = -1;
 387        base->ofs_last = -1;
 388        return base;
 389}
 390
 391static void free_base_data(struct base_data *c)
 392{
 393        if (c->data) {
 394                FREE_AND_NULL(c->data);
 395                get_thread_data()->base_cache_used -= c->size;
 396        }
 397}
 398
 399static void prune_base_data(struct base_data *retain)
 400{
 401        struct base_data *b;
 402        struct thread_local *data = get_thread_data();
 403        for (b = data->base_cache;
 404             data->base_cache_used > delta_base_cache_limit && b;
 405             b = b->child) {
 406                if (b->data && b != retain)
 407                        free_base_data(b);
 408        }
 409}
 410
 411static void link_base_data(struct base_data *base, struct base_data *c)
 412{
 413        if (base)
 414                base->child = c;
 415        else
 416                get_thread_data()->base_cache = c;
 417
 418        c->base = base;
 419        c->child = NULL;
 420        if (c->data)
 421                get_thread_data()->base_cache_used += c->size;
 422        prune_base_data(c);
 423}
 424
 425static void unlink_base_data(struct base_data *c)
 426{
 427        struct base_data *base = c->base;
 428        if (base)
 429                base->child = NULL;
 430        else
 431                get_thread_data()->base_cache = NULL;
 432        free_base_data(c);
 433}
 434
 435static int is_delta_type(enum object_type type)
 436{
 437        return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 438}
 439
 440static void *unpack_entry_data(off_t offset, unsigned long size,
 441                               enum object_type type, struct object_id *oid)
 442{
 443        static char fixed_buf[8192];
 444        int status;
 445        git_zstream stream;
 446        void *buf;
 447        git_hash_ctx c;
 448        char hdr[32];
 449        int hdrlen;
 450
 451        if (!is_delta_type(type)) {
 452                hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(type), size) + 1;
 453                the_hash_algo->init_fn(&c);
 454                the_hash_algo->update_fn(&c, hdr, hdrlen);
 455        } else
 456                oid = NULL;
 457        if (type == OBJ_BLOB && size > big_file_threshold)
 458                buf = fixed_buf;
 459        else
 460                buf = xmallocz(size);
 461
 462        memset(&stream, 0, sizeof(stream));
 463        git_inflate_init(&stream);
 464        stream.next_out = buf;
 465        stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 466
 467        do {
 468                unsigned char *last_out = stream.next_out;
 469                stream.next_in = fill(1);
 470                stream.avail_in = input_len;
 471                status = git_inflate(&stream, 0);
 472                use(input_len - stream.avail_in);
 473                if (oid)
 474                        the_hash_algo->update_fn(&c, last_out, stream.next_out - last_out);
 475                if (buf == fixed_buf) {
 476                        stream.next_out = buf;
 477                        stream.avail_out = sizeof(fixed_buf);
 478                }
 479        } while (status == Z_OK);
 480        if (stream.total_out != size || status != Z_STREAM_END)
 481                bad_object(offset, _("inflate returned %d"), status);
 482        git_inflate_end(&stream);
 483        if (oid)
 484                the_hash_algo->final_fn(oid->hash, &c);
 485        return buf == fixed_buf ? NULL : buf;
 486}
 487
 488static void *unpack_raw_entry(struct object_entry *obj,
 489                              off_t *ofs_offset,
 490                              struct object_id *ref_oid,
 491                              struct object_id *oid)
 492{
 493        unsigned char *p;
 494        unsigned long size, c;
 495        off_t base_offset;
 496        unsigned shift;
 497        void *data;
 498
 499        obj->idx.offset = consumed_bytes;
 500        input_crc32 = crc32(0, NULL, 0);
 501
 502        p = fill(1);
 503        c = *p;
 504        use(1);
 505        obj->type = (c >> 4) & 7;
 506        size = (c & 15);
 507        shift = 4;
 508        while (c & 0x80) {
 509                p = fill(1);
 510                c = *p;
 511                use(1);
 512                size += (c & 0x7f) << shift;
 513                shift += 7;
 514        }
 515        obj->size = size;
 516
 517        switch (obj->type) {
 518        case OBJ_REF_DELTA:
 519                hashcpy(ref_oid->hash, fill(the_hash_algo->rawsz));
 520                use(the_hash_algo->rawsz);
 521                break;
 522        case OBJ_OFS_DELTA:
 523                p = fill(1);
 524                c = *p;
 525                use(1);
 526                base_offset = c & 127;
 527                while (c & 128) {
 528                        base_offset += 1;
 529                        if (!base_offset || MSB(base_offset, 7))
 530                                bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 531                        p = fill(1);
 532                        c = *p;
 533                        use(1);
 534                        base_offset = (base_offset << 7) + (c & 127);
 535                }
 536                *ofs_offset = obj->idx.offset - base_offset;
 537                if (*ofs_offset <= 0 || *ofs_offset >= obj->idx.offset)
 538                        bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 539                break;
 540        case OBJ_COMMIT:
 541        case OBJ_TREE:
 542        case OBJ_BLOB:
 543        case OBJ_TAG:
 544                break;
 545        default:
 546                bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 547        }
 548        obj->hdr_size = consumed_bytes - obj->idx.offset;
 549
 550        data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, oid);
 551        obj->idx.crc32 = input_crc32;
 552        return data;
 553}
 554
 555static void *unpack_data(struct object_entry *obj,
 556                         int (*consume)(const unsigned char *, unsigned long, void *),
 557                         void *cb_data)
 558{
 559        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 560        off_t len = obj[1].idx.offset - from;
 561        unsigned char *data, *inbuf;
 562        git_zstream stream;
 563        int status;
 564
 565        data = xmallocz(consume ? 64*1024 : obj->size);
 566        inbuf = xmalloc((len < 64*1024) ? (int)len : 64*1024);
 567
 568        memset(&stream, 0, sizeof(stream));
 569        git_inflate_init(&stream);
 570        stream.next_out = data;
 571        stream.avail_out = consume ? 64*1024 : obj->size;
 572
 573        do {
 574                ssize_t n = (len < 64*1024) ? (ssize_t)len : 64*1024;
 575                n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 576                if (n < 0)
 577                        die_errno(_("cannot pread pack file"));
 578                if (!n)
 579                        die(Q_("premature end of pack file, %"PRIuMAX" byte missing",
 580                               "premature end of pack file, %"PRIuMAX" bytes missing",
 581                               (unsigned int)len),
 582                            (uintmax_t)len);
 583                from += n;
 584                len -= n;
 585                stream.next_in = inbuf;
 586                stream.avail_in = n;
 587                if (!consume)
 588                        status = git_inflate(&stream, 0);
 589                else {
 590                        do {
 591                                status = git_inflate(&stream, 0);
 592                                if (consume(data, stream.next_out - data, cb_data)) {
 593                                        free(inbuf);
 594                                        free(data);
 595                                        return NULL;
 596                                }
 597                                stream.next_out = data;
 598                                stream.avail_out = 64*1024;
 599                        } while (status == Z_OK && stream.avail_in);
 600                }
 601        } while (len && status == Z_OK && !stream.avail_in);
 602
 603        /* This has been inflated OK when first encountered, so... */
 604        if (status != Z_STREAM_END || stream.total_out != obj->size)
 605                die(_("serious inflate inconsistency"));
 606
 607        git_inflate_end(&stream);
 608        free(inbuf);
 609        if (consume) {
 610                FREE_AND_NULL(data);
 611        }
 612        return data;
 613}
 614
 615static void *get_data_from_pack(struct object_entry *obj)
 616{
 617        return unpack_data(obj, NULL, NULL);
 618}
 619
 620static int compare_ofs_delta_bases(off_t offset1, off_t offset2,
 621                                   enum object_type type1,
 622                                   enum object_type type2)
 623{
 624        int cmp = type1 - type2;
 625        if (cmp)
 626                return cmp;
 627        return offset1 < offset2 ? -1 :
 628               offset1 > offset2 ?  1 :
 629               0;
 630}
 631
 632static int find_ofs_delta(const off_t offset, enum object_type type)
 633{
 634        int first = 0, last = nr_ofs_deltas;
 635
 636        while (first < last) {
 637                int next = first + (last - first) / 2;
 638                struct ofs_delta_entry *delta = &ofs_deltas[next];
 639                int cmp;
 640
 641                cmp = compare_ofs_delta_bases(offset, delta->offset,
 642                                              type, objects[delta->obj_no].type);
 643                if (!cmp)
 644                        return next;
 645                if (cmp < 0) {
 646                        last = next;
 647                        continue;
 648                }
 649                first = next+1;
 650        }
 651        return -first-1;
 652}
 653
 654static void find_ofs_delta_children(off_t offset,
 655                                    int *first_index, int *last_index,
 656                                    enum object_type type)
 657{
 658        int first = find_ofs_delta(offset, type);
 659        int last = first;
 660        int end = nr_ofs_deltas - 1;
 661
 662        if (first < 0) {
 663                *first_index = 0;
 664                *last_index = -1;
 665                return;
 666        }
 667        while (first > 0 && ofs_deltas[first - 1].offset == offset)
 668                --first;
 669        while (last < end && ofs_deltas[last + 1].offset == offset)
 670                ++last;
 671        *first_index = first;
 672        *last_index = last;
 673}
 674
 675static int compare_ref_delta_bases(const unsigned char *sha1,
 676                                   const unsigned char *sha2,
 677                                   enum object_type type1,
 678                                   enum object_type type2)
 679{
 680        int cmp = type1 - type2;
 681        if (cmp)
 682                return cmp;
 683        return hashcmp(sha1, sha2);
 684}
 685
 686static int find_ref_delta(const unsigned char *sha1, enum object_type type)
 687{
 688        int first = 0, last = nr_ref_deltas;
 689
 690        while (first < last) {
 691                int next = first + (last - first) / 2;
 692                struct ref_delta_entry *delta = &ref_deltas[next];
 693                int cmp;
 694
 695                cmp = compare_ref_delta_bases(sha1, delta->sha1,
 696                                              type, objects[delta->obj_no].type);
 697                if (!cmp)
 698                        return next;
 699                if (cmp < 0) {
 700                        last = next;
 701                        continue;
 702                }
 703                first = next+1;
 704        }
 705        return -first-1;
 706}
 707
 708static void find_ref_delta_children(const unsigned char *sha1,
 709                                    int *first_index, int *last_index,
 710                                    enum object_type type)
 711{
 712        int first = find_ref_delta(sha1, type);
 713        int last = first;
 714        int end = nr_ref_deltas - 1;
 715
 716        if (first < 0) {
 717                *first_index = 0;
 718                *last_index = -1;
 719                return;
 720        }
 721        while (first > 0 && !hashcmp(ref_deltas[first - 1].sha1, sha1))
 722                --first;
 723        while (last < end && !hashcmp(ref_deltas[last + 1].sha1, sha1))
 724                ++last;
 725        *first_index = first;
 726        *last_index = last;
 727}
 728
 729struct compare_data {
 730        struct object_entry *entry;
 731        struct git_istream *st;
 732        unsigned char *buf;
 733        unsigned long buf_size;
 734};
 735
 736static int compare_objects(const unsigned char *buf, unsigned long size,
 737                           void *cb_data)
 738{
 739        struct compare_data *data = cb_data;
 740
 741        if (data->buf_size < size) {
 742                free(data->buf);
 743                data->buf = xmalloc(size);
 744                data->buf_size = size;
 745        }
 746
 747        while (size) {
 748                ssize_t len = read_istream(data->st, data->buf, size);
 749                if (len == 0)
 750                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 751                            oid_to_hex(&data->entry->idx.oid));
 752                if (len < 0)
 753                        die(_("unable to read %s"),
 754                            oid_to_hex(&data->entry->idx.oid));
 755                if (memcmp(buf, data->buf, len))
 756                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 757                            oid_to_hex(&data->entry->idx.oid));
 758                size -= len;
 759                buf += len;
 760        }
 761        return 0;
 762}
 763
 764static int check_collison(struct object_entry *entry)
 765{
 766        struct compare_data data;
 767        enum object_type type;
 768        unsigned long size;
 769
 770        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 771                return -1;
 772
 773        memset(&data, 0, sizeof(data));
 774        data.entry = entry;
 775        data.st = open_istream(entry->idx.oid.hash, &type, &size, NULL);
 776        if (!data.st)
 777                return -1;
 778        if (size != entry->size || type != entry->type)
 779                die(_("SHA1 COLLISION FOUND WITH %s !"),
 780                    oid_to_hex(&entry->idx.oid));
 781        unpack_data(entry, compare_objects, &data);
 782        close_istream(data.st);
 783        free(data.buf);
 784        return 0;
 785}
 786
 787static void sha1_object(const void *data, struct object_entry *obj_entry,
 788                        unsigned long size, enum object_type type,
 789                        const struct object_id *oid)
 790{
 791        void *new_data = NULL;
 792        int collision_test_needed = 0;
 793
 794        assert(data || obj_entry);
 795
 796        if (startup_info->have_repository) {
 797                read_lock();
 798                collision_test_needed =
 799                        has_sha1_file_with_flags(oid->hash, OBJECT_INFO_QUICK);
 800                read_unlock();
 801        }
 802
 803        if (collision_test_needed && !data) {
 804                read_lock();
 805                if (!check_collison(obj_entry))
 806                        collision_test_needed = 0;
 807                read_unlock();
 808        }
 809        if (collision_test_needed) {
 810                void *has_data;
 811                enum object_type has_type;
 812                unsigned long has_size;
 813                read_lock();
 814                has_type = sha1_object_info(oid->hash, &has_size);
 815                if (has_type < 0)
 816                        die(_("cannot read existing object info %s"), oid_to_hex(oid));
 817                if (has_type != type || has_size != size)
 818                        die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 819                has_data = read_sha1_file(oid->hash, &has_type, &has_size);
 820                read_unlock();
 821                if (!data)
 822                        data = new_data = get_data_from_pack(obj_entry);
 823                if (!has_data)
 824                        die(_("cannot read existing object %s"), oid_to_hex(oid));
 825                if (size != has_size || type != has_type ||
 826                    memcmp(data, has_data, size) != 0)
 827                        die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 828                free(has_data);
 829        }
 830
 831        if (strict || do_fsck_object) {
 832                read_lock();
 833                if (type == OBJ_BLOB) {
 834                        struct blob *blob = lookup_blob(oid);
 835                        if (blob)
 836                                blob->object.flags |= FLAG_CHECKED;
 837                        else
 838                                die(_("invalid blob object %s"), oid_to_hex(oid));
 839                } else {
 840                        struct object *obj;
 841                        int eaten;
 842                        void *buf = (void *) data;
 843
 844                        assert(data && "data can only be NULL for large _blobs_");
 845
 846                        /*
 847                         * we do not need to free the memory here, as the
 848                         * buf is deleted by the caller.
 849                         */
 850                        obj = parse_object_buffer(oid, type, size, buf,
 851                                                  &eaten);
 852                        if (!obj)
 853                                die(_("invalid %s"), type_name(type));
 854                        if (do_fsck_object &&
 855                            fsck_object(obj, buf, size, &fsck_options))
 856                                die(_("Error in object"));
 857                        if (strict && fsck_walk(obj, NULL, &fsck_options))
 858                                die(_("Not all child objects of %s are reachable"), oid_to_hex(&obj->oid));
 859
 860                        if (obj->type == OBJ_TREE) {
 861                                struct tree *item = (struct tree *) obj;
 862                                item->buffer = NULL;
 863                                obj->parsed = 0;
 864                        }
 865                        if (obj->type == OBJ_COMMIT) {
 866                                struct commit *commit = (struct commit *) obj;
 867                                if (detach_commit_buffer(commit, NULL) != data)
 868                                        die("BUG: parse_object_buffer transmogrified our buffer");
 869                        }
 870                        obj->flags |= FLAG_CHECKED;
 871                }
 872                read_unlock();
 873        }
 874
 875        free(new_data);
 876}
 877
 878/*
 879 * This function is part of find_unresolved_deltas(). There are two
 880 * walkers going in the opposite ways.
 881 *
 882 * The first one in find_unresolved_deltas() traverses down from
 883 * parent node to children, deflating nodes along the way. However,
 884 * memory for deflated nodes is limited by delta_base_cache_limit, so
 885 * at some point parent node's deflated content may be freed.
 886 *
 887 * The second walker is this function, which goes from current node up
 888 * to top parent if necessary to deflate the node. In normal
 889 * situation, its parent node would be already deflated, so it just
 890 * needs to apply delta.
 891 *
 892 * In the worst case scenario, parent node is no longer deflated because
 893 * we're running out of delta_base_cache_limit; we need to re-deflate
 894 * parents, possibly up to the top base.
 895 *
 896 * All deflated objects here are subject to be freed if we exceed
 897 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 898 * just need to make sure the last node is not freed.
 899 */
 900static void *get_base_data(struct base_data *c)
 901{
 902        if (!c->data) {
 903                struct object_entry *obj = c->obj;
 904                struct base_data **delta = NULL;
 905                int delta_nr = 0, delta_alloc = 0;
 906
 907                while (is_delta_type(c->obj->type) && !c->data) {
 908                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 909                        delta[delta_nr++] = c;
 910                        c = c->base;
 911                }
 912                if (!delta_nr) {
 913                        c->data = get_data_from_pack(obj);
 914                        c->size = obj->size;
 915                        get_thread_data()->base_cache_used += c->size;
 916                        prune_base_data(c);
 917                }
 918                for (; delta_nr > 0; delta_nr--) {
 919                        void *base, *raw;
 920                        c = delta[delta_nr - 1];
 921                        obj = c->obj;
 922                        base = get_base_data(c->base);
 923                        raw = get_data_from_pack(obj);
 924                        c->data = patch_delta(
 925                                base, c->base->size,
 926                                raw, obj->size,
 927                                &c->size);
 928                        free(raw);
 929                        if (!c->data)
 930                                bad_object(obj->idx.offset, _("failed to apply delta"));
 931                        get_thread_data()->base_cache_used += c->size;
 932                        prune_base_data(c);
 933                }
 934                free(delta);
 935        }
 936        return c->data;
 937}
 938
 939static void resolve_delta(struct object_entry *delta_obj,
 940                          struct base_data *base, struct base_data *result)
 941{
 942        void *base_data, *delta_data;
 943
 944        if (show_stat) {
 945                int i = delta_obj - objects;
 946                int j = base->obj - objects;
 947                obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 948                deepest_delta_lock();
 949                if (deepest_delta < obj_stat[i].delta_depth)
 950                        deepest_delta = obj_stat[i].delta_depth;
 951                deepest_delta_unlock();
 952                obj_stat[i].base_object_no = j;
 953        }
 954        delta_data = get_data_from_pack(delta_obj);
 955        base_data = get_base_data(base);
 956        result->obj = delta_obj;
 957        result->data = patch_delta(base_data, base->size,
 958                                   delta_data, delta_obj->size, &result->size);
 959        free(delta_data);
 960        if (!result->data)
 961                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 962        hash_object_file(result->data, result->size,
 963                         type_name(delta_obj->real_type), &delta_obj->idx.oid);
 964        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 965                    &delta_obj->idx.oid);
 966        counter_lock();
 967        nr_resolved_deltas++;
 968        counter_unlock();
 969}
 970
 971/*
 972 * Standard boolean compare-and-swap: atomically check whether "*type" is
 973 * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 974 * and return false.
 975 */
 976static int compare_and_swap_type(signed char *type,
 977                                 enum object_type want,
 978                                 enum object_type set)
 979{
 980        enum object_type old;
 981
 982        type_cas_lock();
 983        old = *type;
 984        if (old == want)
 985                *type = set;
 986        type_cas_unlock();
 987
 988        return old == want;
 989}
 990
 991static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 992                                                  struct base_data *prev_base)
 993{
 994        if (base->ref_last == -1 && base->ofs_last == -1) {
 995                find_ref_delta_children(base->obj->idx.oid.hash,
 996                                        &base->ref_first, &base->ref_last,
 997                                        OBJ_REF_DELTA);
 998
 999                find_ofs_delta_children(base->obj->idx.offset,
1000                                        &base->ofs_first, &base->ofs_last,
1001                                        OBJ_OFS_DELTA);
1002
1003                if (base->ref_last == -1 && base->ofs_last == -1) {
1004                        free(base->data);
1005                        return NULL;
1006                }
1007
1008                link_base_data(prev_base, base);
1009        }
1010
1011        if (base->ref_first <= base->ref_last) {
1012                struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
1013                struct base_data *result = alloc_base_data();
1014
1015                if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
1016                                           base->obj->real_type))
1017                        die("BUG: child->real_type != OBJ_REF_DELTA");
1018
1019                resolve_delta(child, base, result);
1020                if (base->ref_first == base->ref_last && base->ofs_last == -1)
1021                        free_base_data(base);
1022
1023                base->ref_first++;
1024                return result;
1025        }
1026
1027        if (base->ofs_first <= base->ofs_last) {
1028                struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
1029                struct base_data *result = alloc_base_data();
1030
1031                assert(child->real_type == OBJ_OFS_DELTA);
1032                child->real_type = base->obj->real_type;
1033                resolve_delta(child, base, result);
1034                if (base->ofs_first == base->ofs_last)
1035                        free_base_data(base);
1036
1037                base->ofs_first++;
1038                return result;
1039        }
1040
1041        unlink_base_data(base);
1042        return NULL;
1043}
1044
1045static void find_unresolved_deltas(struct base_data *base)
1046{
1047        struct base_data *new_base, *prev_base = NULL;
1048        for (;;) {
1049                new_base = find_unresolved_deltas_1(base, prev_base);
1050
1051                if (new_base) {
1052                        prev_base = base;
1053                        base = new_base;
1054                } else {
1055                        free(base);
1056                        base = prev_base;
1057                        if (!base)
1058                                return;
1059                        prev_base = base->base;
1060                }
1061        }
1062}
1063
1064static int compare_ofs_delta_entry(const void *a, const void *b)
1065{
1066        const struct ofs_delta_entry *delta_a = a;
1067        const struct ofs_delta_entry *delta_b = b;
1068
1069        return delta_a->offset < delta_b->offset ? -1 :
1070               delta_a->offset > delta_b->offset ?  1 :
1071               0;
1072}
1073
1074static int compare_ref_delta_entry(const void *a, const void *b)
1075{
1076        const struct ref_delta_entry *delta_a = a;
1077        const struct ref_delta_entry *delta_b = b;
1078
1079        return hashcmp(delta_a->sha1, delta_b->sha1);
1080}
1081
1082static void resolve_base(struct object_entry *obj)
1083{
1084        struct base_data *base_obj = alloc_base_data();
1085        base_obj->obj = obj;
1086        base_obj->data = NULL;
1087        find_unresolved_deltas(base_obj);
1088}
1089
1090#ifndef NO_PTHREADS
1091static void *threaded_second_pass(void *data)
1092{
1093        set_thread_data(data);
1094        for (;;) {
1095                int i;
1096                counter_lock();
1097                display_progress(progress, nr_resolved_deltas);
1098                counter_unlock();
1099                work_lock();
1100                while (nr_dispatched < nr_objects &&
1101                       is_delta_type(objects[nr_dispatched].type))
1102                        nr_dispatched++;
1103                if (nr_dispatched >= nr_objects) {
1104                        work_unlock();
1105                        break;
1106                }
1107                i = nr_dispatched++;
1108                work_unlock();
1109
1110                resolve_base(&objects[i]);
1111        }
1112        return NULL;
1113}
1114#endif
1115
1116/*
1117 * First pass:
1118 * - find locations of all objects;
1119 * - calculate SHA1 of all non-delta objects;
1120 * - remember base (SHA1 or offset) for all deltas.
1121 */
1122static void parse_pack_objects(unsigned char *hash)
1123{
1124        int i, nr_delays = 0;
1125        struct ofs_delta_entry *ofs_delta = ofs_deltas;
1126        struct object_id ref_delta_oid;
1127        struct stat st;
1128
1129        if (verbose)
1130                progress = start_progress(
1131                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1132                                nr_objects);
1133        for (i = 0; i < nr_objects; i++) {
1134                struct object_entry *obj = &objects[i];
1135                void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1136                                              &ref_delta_oid,
1137                                              &obj->idx.oid);
1138                obj->real_type = obj->type;
1139                if (obj->type == OBJ_OFS_DELTA) {
1140                        nr_ofs_deltas++;
1141                        ofs_delta->obj_no = i;
1142                        ofs_delta++;
1143                } else if (obj->type == OBJ_REF_DELTA) {
1144                        ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1145                        hashcpy(ref_deltas[nr_ref_deltas].sha1, ref_delta_oid.hash);
1146                        ref_deltas[nr_ref_deltas].obj_no = i;
1147                        nr_ref_deltas++;
1148                } else if (!data) {
1149                        /* large blobs, check later */
1150                        obj->real_type = OBJ_BAD;
1151                        nr_delays++;
1152                } else
1153                        sha1_object(data, NULL, obj->size, obj->type,
1154                                    &obj->idx.oid);
1155                free(data);
1156                display_progress(progress, i+1);
1157        }
1158        objects[i].idx.offset = consumed_bytes;
1159        stop_progress(&progress);
1160
1161        /* Check pack integrity */
1162        flush();
1163        the_hash_algo->final_fn(hash, &input_ctx);
1164        if (hashcmp(fill(the_hash_algo->rawsz), hash))
1165                die(_("pack is corrupted (SHA1 mismatch)"));
1166        use(the_hash_algo->rawsz);
1167
1168        /* If input_fd is a file, we should have reached its end now. */
1169        if (fstat(input_fd, &st))
1170                die_errno(_("cannot fstat packfile"));
1171        if (S_ISREG(st.st_mode) &&
1172                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1173                die(_("pack has junk at the end"));
1174
1175        for (i = 0; i < nr_objects; i++) {
1176                struct object_entry *obj = &objects[i];
1177                if (obj->real_type != OBJ_BAD)
1178                        continue;
1179                obj->real_type = obj->type;
1180                sha1_object(NULL, obj, obj->size, obj->type,
1181                            &obj->idx.oid);
1182                nr_delays--;
1183        }
1184        if (nr_delays)
1185                die(_("confusion beyond insanity in parse_pack_objects()"));
1186}
1187
1188/*
1189 * Second pass:
1190 * - for all non-delta objects, look if it is used as a base for
1191 *   deltas;
1192 * - if used as a base, uncompress the object and apply all deltas,
1193 *   recursively checking if the resulting object is used as a base
1194 *   for some more deltas.
1195 */
1196static void resolve_deltas(void)
1197{
1198        int i;
1199
1200        if (!nr_ofs_deltas && !nr_ref_deltas)
1201                return;
1202
1203        /* Sort deltas by base SHA1/offset for fast searching */
1204        QSORT(ofs_deltas, nr_ofs_deltas, compare_ofs_delta_entry);
1205        QSORT(ref_deltas, nr_ref_deltas, compare_ref_delta_entry);
1206
1207        if (verbose || show_resolving_progress)
1208                progress = start_progress(_("Resolving deltas"),
1209                                          nr_ref_deltas + nr_ofs_deltas);
1210
1211#ifndef NO_PTHREADS
1212        nr_dispatched = 0;
1213        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1214                init_thread();
1215                for (i = 0; i < nr_threads; i++) {
1216                        int ret = pthread_create(&thread_data[i].thread, NULL,
1217                                                 threaded_second_pass, thread_data + i);
1218                        if (ret)
1219                                die(_("unable to create thread: %s"),
1220                                    strerror(ret));
1221                }
1222                for (i = 0; i < nr_threads; i++)
1223                        pthread_join(thread_data[i].thread, NULL);
1224                cleanup_thread();
1225                return;
1226        }
1227#endif
1228
1229        for (i = 0; i < nr_objects; i++) {
1230                struct object_entry *obj = &objects[i];
1231
1232                if (is_delta_type(obj->type))
1233                        continue;
1234                resolve_base(obj);
1235                display_progress(progress, nr_resolved_deltas);
1236        }
1237}
1238
1239/*
1240 * Third pass:
1241 * - append objects to convert thin pack to full pack if required
1242 * - write the final pack hash
1243 */
1244static void fix_unresolved_deltas(struct hashfile *f);
1245static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_hash)
1246{
1247        if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1248                stop_progress(&progress);
1249                /* Flush remaining pack final hash. */
1250                flush();
1251                return;
1252        }
1253
1254        if (fix_thin_pack) {
1255                struct hashfile *f;
1256                unsigned char read_hash[GIT_MAX_RAWSZ], tail_hash[GIT_MAX_RAWSZ];
1257                struct strbuf msg = STRBUF_INIT;
1258                int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1259                int nr_objects_initial = nr_objects;
1260                if (nr_unresolved <= 0)
1261                        die(_("confusion beyond insanity"));
1262                REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1263                memset(objects + nr_objects + 1, 0,
1264                       nr_unresolved * sizeof(*objects));
1265                f = hashfd(output_fd, curr_pack);
1266                fix_unresolved_deltas(f);
1267                strbuf_addf(&msg, Q_("completed with %d local object",
1268                                     "completed with %d local objects",
1269                                     nr_objects - nr_objects_initial),
1270                            nr_objects - nr_objects_initial);
1271                stop_progress_msg(&progress, msg.buf);
1272                strbuf_release(&msg);
1273                hashclose(f, tail_hash, 0);
1274                hashcpy(read_hash, pack_hash);
1275                fixup_pack_header_footer(output_fd, pack_hash,
1276                                         curr_pack, nr_objects,
1277                                         read_hash, consumed_bytes-the_hash_algo->rawsz);
1278                if (hashcmp(read_hash, tail_hash) != 0)
1279                        die(_("Unexpected tail checksum for %s "
1280                              "(disk corruption?)"), curr_pack);
1281        }
1282        if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1283                die(Q_("pack has %d unresolved delta",
1284                       "pack has %d unresolved deltas",
1285                       nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1286                    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1287}
1288
1289static int write_compressed(struct hashfile *f, void *in, unsigned int size)
1290{
1291        git_zstream stream;
1292        int status;
1293        unsigned char outbuf[4096];
1294
1295        git_deflate_init(&stream, zlib_compression_level);
1296        stream.next_in = in;
1297        stream.avail_in = size;
1298
1299        do {
1300                stream.next_out = outbuf;
1301                stream.avail_out = sizeof(outbuf);
1302                status = git_deflate(&stream, Z_FINISH);
1303                hashwrite(f, outbuf, sizeof(outbuf) - stream.avail_out);
1304        } while (status == Z_OK);
1305
1306        if (status != Z_STREAM_END)
1307                die(_("unable to deflate appended object (%d)"), status);
1308        size = stream.total_out;
1309        git_deflate_end(&stream);
1310        return size;
1311}
1312
1313static struct object_entry *append_obj_to_pack(struct hashfile *f,
1314                               const unsigned char *sha1, void *buf,
1315                               unsigned long size, enum object_type type)
1316{
1317        struct object_entry *obj = &objects[nr_objects++];
1318        unsigned char header[10];
1319        unsigned long s = size;
1320        int n = 0;
1321        unsigned char c = (type << 4) | (s & 15);
1322        s >>= 4;
1323        while (s) {
1324                header[n++] = c | 0x80;
1325                c = s & 0x7f;
1326                s >>= 7;
1327        }
1328        header[n++] = c;
1329        crc32_begin(f);
1330        hashwrite(f, header, n);
1331        obj[0].size = size;
1332        obj[0].hdr_size = n;
1333        obj[0].type = type;
1334        obj[0].real_type = type;
1335        obj[1].idx.offset = obj[0].idx.offset + n;
1336        obj[1].idx.offset += write_compressed(f, buf, size);
1337        obj[0].idx.crc32 = crc32_end(f);
1338        hashflush(f);
1339        hashcpy(obj->idx.oid.hash, sha1);
1340        return obj;
1341}
1342
1343static int delta_pos_compare(const void *_a, const void *_b)
1344{
1345        struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1346        struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1347        return a->obj_no - b->obj_no;
1348}
1349
1350static void fix_unresolved_deltas(struct hashfile *f)
1351{
1352        struct ref_delta_entry **sorted_by_pos;
1353        int i;
1354
1355        /*
1356         * Since many unresolved deltas may well be themselves base objects
1357         * for more unresolved deltas, we really want to include the
1358         * smallest number of base objects that would cover as much delta
1359         * as possible by picking the
1360         * trunc deltas first, allowing for other deltas to resolve without
1361         * additional base objects.  Since most base objects are to be found
1362         * before deltas depending on them, a good heuristic is to start
1363         * resolving deltas in the same order as their position in the pack.
1364         */
1365        ALLOC_ARRAY(sorted_by_pos, nr_ref_deltas);
1366        for (i = 0; i < nr_ref_deltas; i++)
1367                sorted_by_pos[i] = &ref_deltas[i];
1368        QSORT(sorted_by_pos, nr_ref_deltas, delta_pos_compare);
1369
1370        for (i = 0; i < nr_ref_deltas; i++) {
1371                struct ref_delta_entry *d = sorted_by_pos[i];
1372                enum object_type type;
1373                struct base_data *base_obj = alloc_base_data();
1374
1375                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1376                        continue;
1377                base_obj->data = read_sha1_file(d->sha1, &type, &base_obj->size);
1378                if (!base_obj->data)
1379                        continue;
1380
1381                if (check_sha1_signature(d->sha1, base_obj->data,
1382                                base_obj->size, type_name(type)))
1383                        die(_("local object %s is corrupt"), sha1_to_hex(d->sha1));
1384                base_obj->obj = append_obj_to_pack(f, d->sha1,
1385                                        base_obj->data, base_obj->size, type);
1386                find_unresolved_deltas(base_obj);
1387                display_progress(progress, nr_resolved_deltas);
1388        }
1389        free(sorted_by_pos);
1390}
1391
1392static const char *derive_filename(const char *pack_name, const char *suffix,
1393                                   struct strbuf *buf)
1394{
1395        size_t len;
1396        if (!strip_suffix(pack_name, ".pack", &len))
1397                die(_("packfile name '%s' does not end with '.pack'"),
1398                    pack_name);
1399        strbuf_add(buf, pack_name, len);
1400        strbuf_addch(buf, '.');
1401        strbuf_addstr(buf, suffix);
1402        return buf->buf;
1403}
1404
1405static void write_special_file(const char *suffix, const char *msg,
1406                               const char *pack_name, const unsigned char *hash,
1407                               const char **report)
1408{
1409        struct strbuf name_buf = STRBUF_INIT;
1410        const char *filename;
1411        int fd;
1412        int msg_len = strlen(msg);
1413
1414        if (pack_name)
1415                filename = derive_filename(pack_name, suffix, &name_buf);
1416        else
1417                filename = odb_pack_name(&name_buf, hash, suffix);
1418
1419        fd = odb_pack_keep(filename);
1420        if (fd < 0) {
1421                if (errno != EEXIST)
1422                        die_errno(_("cannot write %s file '%s'"),
1423                                  suffix, filename);
1424        } else {
1425                if (msg_len > 0) {
1426                        write_or_die(fd, msg, msg_len);
1427                        write_or_die(fd, "\n", 1);
1428                }
1429                if (close(fd) != 0)
1430                        die_errno(_("cannot close written %s file '%s'"),
1431                                  suffix, filename);
1432                if (report)
1433                        *report = suffix;
1434        }
1435        strbuf_release(&name_buf);
1436}
1437
1438static void final(const char *final_pack_name, const char *curr_pack_name,
1439                  const char *final_index_name, const char *curr_index_name,
1440                  const char *keep_msg, const char *promisor_msg,
1441                  unsigned char *hash)
1442{
1443        const char *report = "pack";
1444        struct strbuf pack_name = STRBUF_INIT;
1445        struct strbuf index_name = STRBUF_INIT;
1446        int err;
1447
1448        if (!from_stdin) {
1449                close(input_fd);
1450        } else {
1451                fsync_or_die(output_fd, curr_pack_name);
1452                err = close(output_fd);
1453                if (err)
1454                        die_errno(_("error while closing pack file"));
1455        }
1456
1457        if (keep_msg)
1458                write_special_file("keep", keep_msg, final_pack_name, hash,
1459                                   &report);
1460        if (promisor_msg)
1461                write_special_file("promisor", promisor_msg, final_pack_name,
1462                                   hash, NULL);
1463
1464        if (final_pack_name != curr_pack_name) {
1465                if (!final_pack_name)
1466                        final_pack_name = odb_pack_name(&pack_name, hash, "pack");
1467                if (finalize_object_file(curr_pack_name, final_pack_name))
1468                        die(_("cannot store pack file"));
1469        } else if (from_stdin)
1470                chmod(final_pack_name, 0444);
1471
1472        if (final_index_name != curr_index_name) {
1473                if (!final_index_name)
1474                        final_index_name = odb_pack_name(&index_name, hash, "idx");
1475                if (finalize_object_file(curr_index_name, final_index_name))
1476                        die(_("cannot store index file"));
1477        } else
1478                chmod(final_index_name, 0444);
1479
1480        if (!from_stdin) {
1481                printf("%s\n", sha1_to_hex(hash));
1482        } else {
1483                struct strbuf buf = STRBUF_INIT;
1484
1485                strbuf_addf(&buf, "%s\t%s\n", report, sha1_to_hex(hash));
1486                write_or_die(1, buf.buf, buf.len);
1487                strbuf_release(&buf);
1488
1489                /*
1490                 * Let's just mimic git-unpack-objects here and write
1491                 * the last part of the input buffer to stdout.
1492                 */
1493                while (input_len) {
1494                        err = xwrite(1, input_buffer + input_offset, input_len);
1495                        if (err <= 0)
1496                                break;
1497                        input_len -= err;
1498                        input_offset += err;
1499                }
1500        }
1501
1502        strbuf_release(&index_name);
1503        strbuf_release(&pack_name);
1504}
1505
1506static int git_index_pack_config(const char *k, const char *v, void *cb)
1507{
1508        struct pack_idx_option *opts = cb;
1509
1510        if (!strcmp(k, "pack.indexversion")) {
1511                opts->version = git_config_int(k, v);
1512                if (opts->version > 2)
1513                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1514                return 0;
1515        }
1516        if (!strcmp(k, "pack.threads")) {
1517                nr_threads = git_config_int(k, v);
1518                if (nr_threads < 0)
1519                        die(_("invalid number of threads specified (%d)"),
1520                            nr_threads);
1521#ifdef NO_PTHREADS
1522                if (nr_threads != 1)
1523                        warning(_("no threads support, ignoring %s"), k);
1524                nr_threads = 1;
1525#endif
1526                return 0;
1527        }
1528        return git_default_config(k, v, cb);
1529}
1530
1531static int cmp_uint32(const void *a_, const void *b_)
1532{
1533        uint32_t a = *((uint32_t *)a_);
1534        uint32_t b = *((uint32_t *)b_);
1535
1536        return (a < b) ? -1 : (a != b);
1537}
1538
1539static void read_v2_anomalous_offsets(struct packed_git *p,
1540                                      struct pack_idx_option *opts)
1541{
1542        const uint32_t *idx1, *idx2;
1543        uint32_t i;
1544
1545        /* The address of the 4-byte offset table */
1546        idx1 = (((const uint32_t *)p->index_data)
1547                + 2 /* 8-byte header */
1548                + 256 /* fan out */
1549                + 5 * p->num_objects /* 20-byte SHA-1 table */
1550                + p->num_objects /* CRC32 table */
1551                );
1552
1553        /* The address of the 8-byte offset table */
1554        idx2 = idx1 + p->num_objects;
1555
1556        for (i = 0; i < p->num_objects; i++) {
1557                uint32_t off = ntohl(idx1[i]);
1558                if (!(off & 0x80000000))
1559                        continue;
1560                off = off & 0x7fffffff;
1561                check_pack_index_ptr(p, &idx2[off * 2]);
1562                if (idx2[off * 2])
1563                        continue;
1564                /*
1565                 * The real offset is ntohl(idx2[off * 2]) in high 4
1566                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1567                 * octets.  But idx2[off * 2] is Zero!!!
1568                 */
1569                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1570                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1571        }
1572
1573        QSORT(opts->anomaly, opts->anomaly_nr, cmp_uint32);
1574}
1575
1576static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1577{
1578        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1579
1580        if (!p)
1581                die(_("Cannot open existing pack file '%s'"), pack_name);
1582        if (open_pack_index(p))
1583                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1584
1585        /* Read the attributes from the existing idx file */
1586        opts->version = p->index_version;
1587
1588        if (opts->version == 2)
1589                read_v2_anomalous_offsets(p, opts);
1590
1591        /*
1592         * Get rid of the idx file as we do not need it anymore.
1593         * NEEDSWORK: extract this bit from free_pack_by_name() in
1594         * sha1_file.c, perhaps?  It shouldn't matter very much as we
1595         * know we haven't installed this pack (hence we never have
1596         * read anything from it).
1597         */
1598        close_pack_index(p);
1599        free(p);
1600}
1601
1602static void show_pack_info(int stat_only)
1603{
1604        int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1605        unsigned long *chain_histogram = NULL;
1606
1607        if (deepest_delta)
1608                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1609
1610        for (i = 0; i < nr_objects; i++) {
1611                struct object_entry *obj = &objects[i];
1612
1613                if (is_delta_type(obj->type))
1614                        chain_histogram[obj_stat[i].delta_depth - 1]++;
1615                if (stat_only)
1616                        continue;
1617                printf("%s %-6s %lu %lu %"PRIuMAX,
1618                       oid_to_hex(&obj->idx.oid),
1619                       type_name(obj->real_type), obj->size,
1620                       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1621                       (uintmax_t)obj->idx.offset);
1622                if (is_delta_type(obj->type)) {
1623                        struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1624                        printf(" %u %s", obj_stat[i].delta_depth,
1625                               oid_to_hex(&bobj->idx.oid));
1626                }
1627                putchar('\n');
1628        }
1629
1630        if (baseobjects)
1631                printf_ln(Q_("non delta: %d object",
1632                             "non delta: %d objects",
1633                             baseobjects),
1634                          baseobjects);
1635        for (i = 0; i < deepest_delta; i++) {
1636                if (!chain_histogram[i])
1637                        continue;
1638                printf_ln(Q_("chain length = %d: %lu object",
1639                             "chain length = %d: %lu objects",
1640                             chain_histogram[i]),
1641                          i + 1,
1642                          chain_histogram[i]);
1643        }
1644}
1645
1646int cmd_index_pack(int argc, const char **argv, const char *prefix)
1647{
1648        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1649        const char *curr_index;
1650        const char *index_name = NULL, *pack_name = NULL;
1651        const char *keep_msg = NULL;
1652        const char *promisor_msg = NULL;
1653        struct strbuf index_name_buf = STRBUF_INIT;
1654        struct pack_idx_entry **idx_objects;
1655        struct pack_idx_option opts;
1656        unsigned char pack_hash[GIT_MAX_RAWSZ];
1657        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1658        int report_end_of_input = 0;
1659
1660        /*
1661         * index-pack never needs to fetch missing objects, since it only
1662         * accesses the repo to do hash collision checks
1663         */
1664        fetch_if_missing = 0;
1665
1666        if (argc == 2 && !strcmp(argv[1], "-h"))
1667                usage(index_pack_usage);
1668
1669        check_replace_refs = 0;
1670        fsck_options.walk = mark_link;
1671
1672        reset_pack_idx_option(&opts);
1673        git_config(git_index_pack_config, &opts);
1674        if (prefix && chdir(prefix))
1675                die(_("Cannot come back to cwd"));
1676
1677        for (i = 1; i < argc; i++) {
1678                const char *arg = argv[i];
1679
1680                if (*arg == '-') {
1681                        if (!strcmp(arg, "--stdin")) {
1682                                from_stdin = 1;
1683                        } else if (!strcmp(arg, "--fix-thin")) {
1684                                fix_thin_pack = 1;
1685                        } else if (skip_to_optional_arg(arg, "--strict", &arg)) {
1686                                strict = 1;
1687                                do_fsck_object = 1;
1688                                fsck_set_msg_types(&fsck_options, arg);
1689                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1690                                strict = 1;
1691                                check_self_contained_and_connected = 1;
1692                        } else if (!strcmp(arg, "--fsck-objects")) {
1693                                do_fsck_object = 1;
1694                        } else if (!strcmp(arg, "--verify")) {
1695                                verify = 1;
1696                        } else if (!strcmp(arg, "--verify-stat")) {
1697                                verify = 1;
1698                                show_stat = 1;
1699                        } else if (!strcmp(arg, "--verify-stat-only")) {
1700                                verify = 1;
1701                                show_stat = 1;
1702                                stat_only = 1;
1703                        } else if (skip_to_optional_arg(arg, "--keep", &keep_msg)) {
1704                                ; /* nothing to do */
1705                        } else if (skip_to_optional_arg(arg, "--promisor", &promisor_msg)) {
1706                                ; /* already parsed */
1707                        } else if (starts_with(arg, "--threads=")) {
1708                                char *end;
1709                                nr_threads = strtoul(arg+10, &end, 0);
1710                                if (!arg[10] || *end || nr_threads < 0)
1711                                        usage(index_pack_usage);
1712#ifdef NO_PTHREADS
1713                                if (nr_threads != 1)
1714                                        warning(_("no threads support, "
1715                                                  "ignoring %s"), arg);
1716                                nr_threads = 1;
1717#endif
1718                        } else if (starts_with(arg, "--pack_header=")) {
1719                                struct pack_header *hdr;
1720                                char *c;
1721
1722                                hdr = (struct pack_header *)input_buffer;
1723                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1724                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1725                                if (*c != ',')
1726                                        die(_("bad %s"), arg);
1727                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1728                                if (*c)
1729                                        die(_("bad %s"), arg);
1730                                input_len = sizeof(*hdr);
1731                        } else if (!strcmp(arg, "-v")) {
1732                                verbose = 1;
1733                        } else if (!strcmp(arg, "--show-resolving-progress")) {
1734                                show_resolving_progress = 1;
1735                        } else if (!strcmp(arg, "--report-end-of-input")) {
1736                                report_end_of_input = 1;
1737                        } else if (!strcmp(arg, "-o")) {
1738                                if (index_name || (i+1) >= argc)
1739                                        usage(index_pack_usage);
1740                                index_name = argv[++i];
1741                        } else if (starts_with(arg, "--index-version=")) {
1742                                char *c;
1743                                opts.version = strtoul(arg + 16, &c, 10);
1744                                if (opts.version > 2)
1745                                        die(_("bad %s"), arg);
1746                                if (*c == ',')
1747                                        opts.off32_limit = strtoul(c+1, &c, 0);
1748                                if (*c || opts.off32_limit & 0x80000000)
1749                                        die(_("bad %s"), arg);
1750                        } else if (skip_prefix(arg, "--max-input-size=", &arg)) {
1751                                max_input_size = strtoumax(arg, NULL, 10);
1752                        } else
1753                                usage(index_pack_usage);
1754                        continue;
1755                }
1756
1757                if (pack_name)
1758                        usage(index_pack_usage);
1759                pack_name = arg;
1760        }
1761
1762        if (!pack_name && !from_stdin)
1763                usage(index_pack_usage);
1764        if (fix_thin_pack && !from_stdin)
1765                die(_("--fix-thin cannot be used without --stdin"));
1766        if (from_stdin && !startup_info->have_repository)
1767                die(_("--stdin requires a git repository"));
1768        if (!index_name && pack_name)
1769                index_name = derive_filename(pack_name, "idx", &index_name_buf);
1770
1771        if (verify) {
1772                if (!index_name)
1773                        die(_("--verify with no packfile name given"));
1774                read_idx_option(&opts, index_name);
1775                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1776        }
1777        if (strict)
1778                opts.flags |= WRITE_IDX_STRICT;
1779
1780#ifndef NO_PTHREADS
1781        if (!nr_threads) {
1782                nr_threads = online_cpus();
1783                /* An experiment showed that more threads does not mean faster */
1784                if (nr_threads > 3)
1785                        nr_threads = 3;
1786        }
1787#endif
1788
1789        curr_pack = open_pack_file(pack_name);
1790        parse_pack_header();
1791        objects = xcalloc(st_add(nr_objects, 1), sizeof(struct object_entry));
1792        if (show_stat)
1793                obj_stat = xcalloc(st_add(nr_objects, 1), sizeof(struct object_stat));
1794        ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
1795        parse_pack_objects(pack_hash);
1796        if (report_end_of_input)
1797                write_in_full(2, "\0", 1);
1798        resolve_deltas();
1799        conclude_pack(fix_thin_pack, curr_pack, pack_hash);
1800        free(ofs_deltas);
1801        free(ref_deltas);
1802        if (strict)
1803                foreign_nr = check_objects();
1804
1805        if (show_stat)
1806                show_pack_info(stat_only);
1807
1808        ALLOC_ARRAY(idx_objects, nr_objects);
1809        for (i = 0; i < nr_objects; i++)
1810                idx_objects[i] = &objects[i].idx;
1811        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_hash);
1812        free(idx_objects);
1813
1814        if (!verify)
1815                final(pack_name, curr_pack,
1816                      index_name, curr_index,
1817                      keep_msg, promisor_msg,
1818                      pack_hash);
1819        else
1820                close(input_fd);
1821        free(objects);
1822        strbuf_release(&index_name_buf);
1823        if (pack_name == NULL)
1824                free((void *) curr_pack);
1825        if (index_name == NULL)
1826                free((void *) curr_index);
1827
1828        /*
1829         * Let the caller know this pack is not self contained
1830         */
1831        if (check_self_contained_and_connected && foreign_nr)
1832                return 1;
1833
1834        return 0;
1835}