builtin / index-pack.con commit git-multimail: update to release 1.1.1 (5bdb7a7)
   1#include "builtin.h"
   2#include "delta.h"
   3#include "pack.h"
   4#include "csum-file.h"
   5#include "blob.h"
   6#include "commit.h"
   7#include "tag.h"
   8#include "tree.h"
   9#include "progress.h"
  10#include "fsck.h"
  11#include "exec_cmd.h"
  12#include "streaming.h"
  13#include "thread-utils.h"
  14
  15static const char index_pack_usage[] =
  16"git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
  17
  18struct object_entry {
  19        struct pack_idx_entry idx;
  20        unsigned long size;
  21        unsigned char hdr_size;
  22        signed char type;
  23        signed char real_type;
  24};
  25
  26struct object_stat {
  27        unsigned delta_depth;
  28        int base_object_no;
  29};
  30
  31struct base_data {
  32        struct base_data *base;
  33        struct base_data *child;
  34        struct object_entry *obj;
  35        void *data;
  36        unsigned long size;
  37        int ref_first, ref_last;
  38        int ofs_first, ofs_last;
  39};
  40
  41struct thread_local {
  42#ifndef NO_PTHREADS
  43        pthread_t thread;
  44#endif
  45        struct base_data *base_cache;
  46        size_t base_cache_used;
  47        int pack_fd;
  48};
  49
  50#define FLAG_LINK (1u<<20)
  51#define FLAG_CHECKED (1u<<21)
  52
  53struct ofs_delta_entry {
  54        off_t offset;
  55        int obj_no;
  56};
  57
  58struct ref_delta_entry {
  59        unsigned char sha1[20];
  60        int obj_no;
  61};
  62
  63static struct object_entry *objects;
  64static struct object_stat *obj_stat;
  65static struct ofs_delta_entry *ofs_deltas;
  66static struct ref_delta_entry *ref_deltas;
  67static struct thread_local nothread_data;
  68static int nr_objects;
  69static int nr_ofs_deltas;
  70static int nr_ref_deltas;
  71static int ref_deltas_alloc;
  72static int nr_resolved_deltas;
  73static int nr_threads;
  74
  75static int from_stdin;
  76static int strict;
  77static int do_fsck_object;
  78static int verbose;
  79static int show_stat;
  80static int check_self_contained_and_connected;
  81
  82static struct progress *progress;
  83
  84/* We always read in 4kB chunks. */
  85static unsigned char input_buffer[4096];
  86static unsigned int input_offset, input_len;
  87static off_t consumed_bytes;
  88static unsigned deepest_delta;
  89static git_SHA_CTX input_ctx;
  90static uint32_t input_crc32;
  91static int input_fd, output_fd;
  92static const char *curr_pack;
  93
  94#ifndef NO_PTHREADS
  95
  96static struct thread_local *thread_data;
  97static int nr_dispatched;
  98static int threads_active;
  99
 100static pthread_mutex_t read_mutex;
 101#define read_lock()             lock_mutex(&read_mutex)
 102#define read_unlock()           unlock_mutex(&read_mutex)
 103
 104static pthread_mutex_t counter_mutex;
 105#define counter_lock()          lock_mutex(&counter_mutex)
 106#define counter_unlock()        unlock_mutex(&counter_mutex)
 107
 108static pthread_mutex_t work_mutex;
 109#define work_lock()             lock_mutex(&work_mutex)
 110#define work_unlock()           unlock_mutex(&work_mutex)
 111
 112static pthread_mutex_t deepest_delta_mutex;
 113#define deepest_delta_lock()    lock_mutex(&deepest_delta_mutex)
 114#define deepest_delta_unlock()  unlock_mutex(&deepest_delta_mutex)
 115
 116static pthread_mutex_t type_cas_mutex;
 117#define type_cas_lock()         lock_mutex(&type_cas_mutex)
 118#define type_cas_unlock()       unlock_mutex(&type_cas_mutex)
 119
 120static pthread_key_t key;
 121
 122static inline void lock_mutex(pthread_mutex_t *mutex)
 123{
 124        if (threads_active)
 125                pthread_mutex_lock(mutex);
 126}
 127
 128static inline void unlock_mutex(pthread_mutex_t *mutex)
 129{
 130        if (threads_active)
 131                pthread_mutex_unlock(mutex);
 132}
 133
 134/*
 135 * Mutex and conditional variable can't be statically-initialized on Windows.
 136 */
 137static void init_thread(void)
 138{
 139        int i;
 140        init_recursive_mutex(&read_mutex);
 141        pthread_mutex_init(&counter_mutex, NULL);
 142        pthread_mutex_init(&work_mutex, NULL);
 143        pthread_mutex_init(&type_cas_mutex, NULL);
 144        if (show_stat)
 145                pthread_mutex_init(&deepest_delta_mutex, NULL);
 146        pthread_key_create(&key, NULL);
 147        thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 148        for (i = 0; i < nr_threads; i++) {
 149                thread_data[i].pack_fd = open(curr_pack, O_RDONLY);
 150                if (thread_data[i].pack_fd == -1)
 151                        die_errno(_("unable to open %s"), curr_pack);
 152        }
 153
 154        threads_active = 1;
 155}
 156
 157static void cleanup_thread(void)
 158{
 159        int i;
 160        if (!threads_active)
 161                return;
 162        threads_active = 0;
 163        pthread_mutex_destroy(&read_mutex);
 164        pthread_mutex_destroy(&counter_mutex);
 165        pthread_mutex_destroy(&work_mutex);
 166        pthread_mutex_destroy(&type_cas_mutex);
 167        if (show_stat)
 168                pthread_mutex_destroy(&deepest_delta_mutex);
 169        for (i = 0; i < nr_threads; i++)
 170                close(thread_data[i].pack_fd);
 171        pthread_key_delete(key);
 172        free(thread_data);
 173}
 174
 175#else
 176
 177#define read_lock()
 178#define read_unlock()
 179
 180#define counter_lock()
 181#define counter_unlock()
 182
 183#define work_lock()
 184#define work_unlock()
 185
 186#define deepest_delta_lock()
 187#define deepest_delta_unlock()
 188
 189#define type_cas_lock()
 190#define type_cas_unlock()
 191
 192#endif
 193
 194
 195static int mark_link(struct object *obj, int type, void *data)
 196{
 197        if (!obj)
 198                return -1;
 199
 200        if (type != OBJ_ANY && obj->type != type)
 201                die(_("object type mismatch at %s"), sha1_to_hex(obj->sha1));
 202
 203        obj->flags |= FLAG_LINK;
 204        return 0;
 205}
 206
 207/* The content of each linked object must have been checked
 208   or it must be already present in the object database */
 209static unsigned check_object(struct object *obj)
 210{
 211        if (!obj)
 212                return 0;
 213
 214        if (!(obj->flags & FLAG_LINK))
 215                return 0;
 216
 217        if (!(obj->flags & FLAG_CHECKED)) {
 218                unsigned long size;
 219                int type = sha1_object_info(obj->sha1, &size);
 220                if (type <= 0)
 221                        die(_("did not receive expected object %s"),
 222                              sha1_to_hex(obj->sha1));
 223                if (type != obj->type)
 224                        die(_("object %s: expected type %s, found %s"),
 225                            sha1_to_hex(obj->sha1),
 226                            typename(obj->type), typename(type));
 227                obj->flags |= FLAG_CHECKED;
 228                return 1;
 229        }
 230
 231        return 0;
 232}
 233
 234static unsigned check_objects(void)
 235{
 236        unsigned i, max, foreign_nr = 0;
 237
 238        max = get_max_object_index();
 239        for (i = 0; i < max; i++)
 240                foreign_nr += check_object(get_indexed_object(i));
 241        return foreign_nr;
 242}
 243
 244
 245/* Discard current buffer used content. */
 246static void flush(void)
 247{
 248        if (input_offset) {
 249                if (output_fd >= 0)
 250                        write_or_die(output_fd, input_buffer, input_offset);
 251                git_SHA1_Update(&input_ctx, input_buffer, input_offset);
 252                memmove(input_buffer, input_buffer + input_offset, input_len);
 253                input_offset = 0;
 254        }
 255}
 256
 257/*
 258 * Make sure at least "min" bytes are available in the buffer, and
 259 * return the pointer to the buffer.
 260 */
 261static void *fill(int min)
 262{
 263        if (min <= input_len)
 264                return input_buffer + input_offset;
 265        if (min > sizeof(input_buffer))
 266                die(Q_("cannot fill %d byte",
 267                       "cannot fill %d bytes",
 268                       min),
 269                    min);
 270        flush();
 271        do {
 272                ssize_t ret = xread(input_fd, input_buffer + input_len,
 273                                sizeof(input_buffer) - input_len);
 274                if (ret <= 0) {
 275                        if (!ret)
 276                                die(_("early EOF"));
 277                        die_errno(_("read error on input"));
 278                }
 279                input_len += ret;
 280                if (from_stdin)
 281                        display_throughput(progress, consumed_bytes + input_len);
 282        } while (input_len < min);
 283        return input_buffer;
 284}
 285
 286static void use(int bytes)
 287{
 288        if (bytes > input_len)
 289                die(_("used more bytes than were available"));
 290        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 291        input_len -= bytes;
 292        input_offset += bytes;
 293
 294        /* make sure off_t is sufficiently large not to wrap */
 295        if (signed_add_overflows(consumed_bytes, bytes))
 296                die(_("pack too large for current definition of off_t"));
 297        consumed_bytes += bytes;
 298}
 299
 300static const char *open_pack_file(const char *pack_name)
 301{
 302        if (from_stdin) {
 303                input_fd = 0;
 304                if (!pack_name) {
 305                        static char tmp_file[PATH_MAX];
 306                        output_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
 307                                                "pack/tmp_pack_XXXXXX");
 308                        pack_name = xstrdup(tmp_file);
 309                } else
 310                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 311                if (output_fd < 0)
 312                        die_errno(_("unable to create '%s'"), pack_name);
 313                nothread_data.pack_fd = output_fd;
 314        } else {
 315                input_fd = open(pack_name, O_RDONLY);
 316                if (input_fd < 0)
 317                        die_errno(_("cannot open packfile '%s'"), pack_name);
 318                output_fd = -1;
 319                nothread_data.pack_fd = input_fd;
 320        }
 321        git_SHA1_Init(&input_ctx);
 322        return pack_name;
 323}
 324
 325static void parse_pack_header(void)
 326{
 327        struct pack_header *hdr = fill(sizeof(struct pack_header));
 328
 329        /* Header consistency check */
 330        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 331                die(_("pack signature mismatch"));
 332        if (!pack_version_ok(hdr->hdr_version))
 333                die(_("pack version %"PRIu32" unsupported"),
 334                        ntohl(hdr->hdr_version));
 335
 336        nr_objects = ntohl(hdr->hdr_entries);
 337        use(sizeof(struct pack_header));
 338}
 339
 340static NORETURN void bad_object(unsigned long offset, const char *format,
 341                       ...) __attribute__((format (printf, 2, 3)));
 342
 343static NORETURN void bad_object(unsigned long offset, const char *format, ...)
 344{
 345        va_list params;
 346        char buf[1024];
 347
 348        va_start(params, format);
 349        vsnprintf(buf, sizeof(buf), format, params);
 350        va_end(params);
 351        die(_("pack has bad object at offset %lu: %s"), offset, buf);
 352}
 353
 354static inline struct thread_local *get_thread_data(void)
 355{
 356#ifndef NO_PTHREADS
 357        if (threads_active)
 358                return pthread_getspecific(key);
 359        assert(!threads_active &&
 360               "This should only be reached when all threads are gone");
 361#endif
 362        return &nothread_data;
 363}
 364
 365#ifndef NO_PTHREADS
 366static void set_thread_data(struct thread_local *data)
 367{
 368        if (threads_active)
 369                pthread_setspecific(key, data);
 370}
 371#endif
 372
 373static struct base_data *alloc_base_data(void)
 374{
 375        struct base_data *base = xcalloc(1, sizeof(struct base_data));
 376        base->ref_last = -1;
 377        base->ofs_last = -1;
 378        return base;
 379}
 380
 381static void free_base_data(struct base_data *c)
 382{
 383        if (c->data) {
 384                free(c->data);
 385                c->data = NULL;
 386                get_thread_data()->base_cache_used -= c->size;
 387        }
 388}
 389
 390static void prune_base_data(struct base_data *retain)
 391{
 392        struct base_data *b;
 393        struct thread_local *data = get_thread_data();
 394        for (b = data->base_cache;
 395             data->base_cache_used > delta_base_cache_limit && b;
 396             b = b->child) {
 397                if (b->data && b != retain)
 398                        free_base_data(b);
 399        }
 400}
 401
 402static void link_base_data(struct base_data *base, struct base_data *c)
 403{
 404        if (base)
 405                base->child = c;
 406        else
 407                get_thread_data()->base_cache = c;
 408
 409        c->base = base;
 410        c->child = NULL;
 411        if (c->data)
 412                get_thread_data()->base_cache_used += c->size;
 413        prune_base_data(c);
 414}
 415
 416static void unlink_base_data(struct base_data *c)
 417{
 418        struct base_data *base = c->base;
 419        if (base)
 420                base->child = NULL;
 421        else
 422                get_thread_data()->base_cache = NULL;
 423        free_base_data(c);
 424}
 425
 426static int is_delta_type(enum object_type type)
 427{
 428        return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 429}
 430
 431static void *unpack_entry_data(unsigned long offset, unsigned long size,
 432                               enum object_type type, unsigned char *sha1)
 433{
 434        static char fixed_buf[8192];
 435        int status;
 436        git_zstream stream;
 437        void *buf;
 438        git_SHA_CTX c;
 439        char hdr[32];
 440        int hdrlen;
 441
 442        if (!is_delta_type(type)) {
 443                hdrlen = sprintf(hdr, "%s %lu", typename(type), size) + 1;
 444                git_SHA1_Init(&c);
 445                git_SHA1_Update(&c, hdr, hdrlen);
 446        } else
 447                sha1 = NULL;
 448        if (type == OBJ_BLOB && size > big_file_threshold)
 449                buf = fixed_buf;
 450        else
 451                buf = xmallocz(size);
 452
 453        memset(&stream, 0, sizeof(stream));
 454        git_inflate_init(&stream);
 455        stream.next_out = buf;
 456        stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 457
 458        do {
 459                unsigned char *last_out = stream.next_out;
 460                stream.next_in = fill(1);
 461                stream.avail_in = input_len;
 462                status = git_inflate(&stream, 0);
 463                use(input_len - stream.avail_in);
 464                if (sha1)
 465                        git_SHA1_Update(&c, last_out, stream.next_out - last_out);
 466                if (buf == fixed_buf) {
 467                        stream.next_out = buf;
 468                        stream.avail_out = sizeof(fixed_buf);
 469                }
 470        } while (status == Z_OK);
 471        if (stream.total_out != size || status != Z_STREAM_END)
 472                bad_object(offset, _("inflate returned %d"), status);
 473        git_inflate_end(&stream);
 474        if (sha1)
 475                git_SHA1_Final(sha1, &c);
 476        return buf == fixed_buf ? NULL : buf;
 477}
 478
 479static void *unpack_raw_entry(struct object_entry *obj,
 480                              off_t *ofs_offset,
 481                              unsigned char *ref_sha1,
 482                              unsigned char *sha1)
 483{
 484        unsigned char *p;
 485        unsigned long size, c;
 486        off_t base_offset;
 487        unsigned shift;
 488        void *data;
 489
 490        obj->idx.offset = consumed_bytes;
 491        input_crc32 = crc32(0, NULL, 0);
 492
 493        p = fill(1);
 494        c = *p;
 495        use(1);
 496        obj->type = (c >> 4) & 7;
 497        size = (c & 15);
 498        shift = 4;
 499        while (c & 0x80) {
 500                p = fill(1);
 501                c = *p;
 502                use(1);
 503                size += (c & 0x7f) << shift;
 504                shift += 7;
 505        }
 506        obj->size = size;
 507
 508        switch (obj->type) {
 509        case OBJ_REF_DELTA:
 510                hashcpy(ref_sha1, fill(20));
 511                use(20);
 512                break;
 513        case OBJ_OFS_DELTA:
 514                p = fill(1);
 515                c = *p;
 516                use(1);
 517                base_offset = c & 127;
 518                while (c & 128) {
 519                        base_offset += 1;
 520                        if (!base_offset || MSB(base_offset, 7))
 521                                bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 522                        p = fill(1);
 523                        c = *p;
 524                        use(1);
 525                        base_offset = (base_offset << 7) + (c & 127);
 526                }
 527                *ofs_offset = obj->idx.offset - base_offset;
 528                if (*ofs_offset <= 0 || *ofs_offset >= obj->idx.offset)
 529                        bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 530                break;
 531        case OBJ_COMMIT:
 532        case OBJ_TREE:
 533        case OBJ_BLOB:
 534        case OBJ_TAG:
 535                break;
 536        default:
 537                bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 538        }
 539        obj->hdr_size = consumed_bytes - obj->idx.offset;
 540
 541        data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, sha1);
 542        obj->idx.crc32 = input_crc32;
 543        return data;
 544}
 545
 546static void *unpack_data(struct object_entry *obj,
 547                         int (*consume)(const unsigned char *, unsigned long, void *),
 548                         void *cb_data)
 549{
 550        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 551        unsigned long len = obj[1].idx.offset - from;
 552        unsigned char *data, *inbuf;
 553        git_zstream stream;
 554        int status;
 555
 556        data = xmallocz(consume ? 64*1024 : obj->size);
 557        inbuf = xmalloc((len < 64*1024) ? len : 64*1024);
 558
 559        memset(&stream, 0, sizeof(stream));
 560        git_inflate_init(&stream);
 561        stream.next_out = data;
 562        stream.avail_out = consume ? 64*1024 : obj->size;
 563
 564        do {
 565                ssize_t n = (len < 64*1024) ? len : 64*1024;
 566                n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 567                if (n < 0)
 568                        die_errno(_("cannot pread pack file"));
 569                if (!n)
 570                        die(Q_("premature end of pack file, %lu byte missing",
 571                               "premature end of pack file, %lu bytes missing",
 572                               len),
 573                            len);
 574                from += n;
 575                len -= n;
 576                stream.next_in = inbuf;
 577                stream.avail_in = n;
 578                if (!consume)
 579                        status = git_inflate(&stream, 0);
 580                else {
 581                        do {
 582                                status = git_inflate(&stream, 0);
 583                                if (consume(data, stream.next_out - data, cb_data)) {
 584                                        free(inbuf);
 585                                        free(data);
 586                                        return NULL;
 587                                }
 588                                stream.next_out = data;
 589                                stream.avail_out = 64*1024;
 590                        } while (status == Z_OK && stream.avail_in);
 591                }
 592        } while (len && status == Z_OK && !stream.avail_in);
 593
 594        /* This has been inflated OK when first encountered, so... */
 595        if (status != Z_STREAM_END || stream.total_out != obj->size)
 596                die(_("serious inflate inconsistency"));
 597
 598        git_inflate_end(&stream);
 599        free(inbuf);
 600        if (consume) {
 601                free(data);
 602                data = NULL;
 603        }
 604        return data;
 605}
 606
 607static void *get_data_from_pack(struct object_entry *obj)
 608{
 609        return unpack_data(obj, NULL, NULL);
 610}
 611
 612static int compare_ofs_delta_bases(off_t offset1, off_t offset2,
 613                                   enum object_type type1,
 614                                   enum object_type type2)
 615{
 616        int cmp = type1 - type2;
 617        if (cmp)
 618                return cmp;
 619        return offset1 < offset2 ? -1 :
 620               offset1 > offset2 ?  1 :
 621               0;
 622}
 623
 624static int find_ofs_delta(const off_t offset, enum object_type type)
 625{
 626        int first = 0, last = nr_ofs_deltas;
 627
 628        while (first < last) {
 629                int next = (first + last) / 2;
 630                struct ofs_delta_entry *delta = &ofs_deltas[next];
 631                int cmp;
 632
 633                cmp = compare_ofs_delta_bases(offset, delta->offset,
 634                                              type, objects[delta->obj_no].type);
 635                if (!cmp)
 636                        return next;
 637                if (cmp < 0) {
 638                        last = next;
 639                        continue;
 640                }
 641                first = next+1;
 642        }
 643        return -first-1;
 644}
 645
 646static void find_ofs_delta_children(off_t offset,
 647                                    int *first_index, int *last_index,
 648                                    enum object_type type)
 649{
 650        int first = find_ofs_delta(offset, type);
 651        int last = first;
 652        int end = nr_ofs_deltas - 1;
 653
 654        if (first < 0) {
 655                *first_index = 0;
 656                *last_index = -1;
 657                return;
 658        }
 659        while (first > 0 && ofs_deltas[first - 1].offset == offset)
 660                --first;
 661        while (last < end && ofs_deltas[last + 1].offset == offset)
 662                ++last;
 663        *first_index = first;
 664        *last_index = last;
 665}
 666
 667static int compare_ref_delta_bases(const unsigned char *sha1,
 668                                   const unsigned char *sha2,
 669                                   enum object_type type1,
 670                                   enum object_type type2)
 671{
 672        int cmp = type1 - type2;
 673        if (cmp)
 674                return cmp;
 675        return hashcmp(sha1, sha2);
 676}
 677
 678static int find_ref_delta(const unsigned char *sha1, enum object_type type)
 679{
 680        int first = 0, last = nr_ref_deltas;
 681
 682        while (first < last) {
 683                int next = (first + last) / 2;
 684                struct ref_delta_entry *delta = &ref_deltas[next];
 685                int cmp;
 686
 687                cmp = compare_ref_delta_bases(sha1, delta->sha1,
 688                                              type, objects[delta->obj_no].type);
 689                if (!cmp)
 690                        return next;
 691                if (cmp < 0) {
 692                        last = next;
 693                        continue;
 694                }
 695                first = next+1;
 696        }
 697        return -first-1;
 698}
 699
 700static void find_ref_delta_children(const unsigned char *sha1,
 701                                    int *first_index, int *last_index,
 702                                    enum object_type type)
 703{
 704        int first = find_ref_delta(sha1, type);
 705        int last = first;
 706        int end = nr_ref_deltas - 1;
 707
 708        if (first < 0) {
 709                *first_index = 0;
 710                *last_index = -1;
 711                return;
 712        }
 713        while (first > 0 && !hashcmp(ref_deltas[first - 1].sha1, sha1))
 714                --first;
 715        while (last < end && !hashcmp(ref_deltas[last + 1].sha1, sha1))
 716                ++last;
 717        *first_index = first;
 718        *last_index = last;
 719}
 720
 721struct compare_data {
 722        struct object_entry *entry;
 723        struct git_istream *st;
 724        unsigned char *buf;
 725        unsigned long buf_size;
 726};
 727
 728static int compare_objects(const unsigned char *buf, unsigned long size,
 729                           void *cb_data)
 730{
 731        struct compare_data *data = cb_data;
 732
 733        if (data->buf_size < size) {
 734                free(data->buf);
 735                data->buf = xmalloc(size);
 736                data->buf_size = size;
 737        }
 738
 739        while (size) {
 740                ssize_t len = read_istream(data->st, data->buf, size);
 741                if (len == 0)
 742                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 743                            sha1_to_hex(data->entry->idx.sha1));
 744                if (len < 0)
 745                        die(_("unable to read %s"),
 746                            sha1_to_hex(data->entry->idx.sha1));
 747                if (memcmp(buf, data->buf, len))
 748                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 749                            sha1_to_hex(data->entry->idx.sha1));
 750                size -= len;
 751                buf += len;
 752        }
 753        return 0;
 754}
 755
 756static int check_collison(struct object_entry *entry)
 757{
 758        struct compare_data data;
 759        enum object_type type;
 760        unsigned long size;
 761
 762        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 763                return -1;
 764
 765        memset(&data, 0, sizeof(data));
 766        data.entry = entry;
 767        data.st = open_istream(entry->idx.sha1, &type, &size, NULL);
 768        if (!data.st)
 769                return -1;
 770        if (size != entry->size || type != entry->type)
 771                die(_("SHA1 COLLISION FOUND WITH %s !"),
 772                    sha1_to_hex(entry->idx.sha1));
 773        unpack_data(entry, compare_objects, &data);
 774        close_istream(data.st);
 775        free(data.buf);
 776        return 0;
 777}
 778
 779static void sha1_object(const void *data, struct object_entry *obj_entry,
 780                        unsigned long size, enum object_type type,
 781                        const unsigned char *sha1)
 782{
 783        void *new_data = NULL;
 784        int collision_test_needed;
 785
 786        assert(data || obj_entry);
 787
 788        read_lock();
 789        collision_test_needed = has_sha1_file_with_flags(sha1, HAS_SHA1_QUICK);
 790        read_unlock();
 791
 792        if (collision_test_needed && !data) {
 793                read_lock();
 794                if (!check_collison(obj_entry))
 795                        collision_test_needed = 0;
 796                read_unlock();
 797        }
 798        if (collision_test_needed) {
 799                void *has_data;
 800                enum object_type has_type;
 801                unsigned long has_size;
 802                read_lock();
 803                has_type = sha1_object_info(sha1, &has_size);
 804                if (has_type != type || has_size != size)
 805                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 806                has_data = read_sha1_file(sha1, &has_type, &has_size);
 807                read_unlock();
 808                if (!data)
 809                        data = new_data = get_data_from_pack(obj_entry);
 810                if (!has_data)
 811                        die(_("cannot read existing object %s"), sha1_to_hex(sha1));
 812                if (size != has_size || type != has_type ||
 813                    memcmp(data, has_data, size) != 0)
 814                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 815                free(has_data);
 816        }
 817
 818        if (strict) {
 819                read_lock();
 820                if (type == OBJ_BLOB) {
 821                        struct blob *blob = lookup_blob(sha1);
 822                        if (blob)
 823                                blob->object.flags |= FLAG_CHECKED;
 824                        else
 825                                die(_("invalid blob object %s"), sha1_to_hex(sha1));
 826                } else {
 827                        struct object *obj;
 828                        int eaten;
 829                        void *buf = (void *) data;
 830
 831                        assert(data && "data can only be NULL for large _blobs_");
 832
 833                        /*
 834                         * we do not need to free the memory here, as the
 835                         * buf is deleted by the caller.
 836                         */
 837                        obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 838                        if (!obj)
 839                                die(_("invalid %s"), typename(type));
 840                        if (do_fsck_object &&
 841                            fsck_object(obj, buf, size, 1,
 842                                    fsck_error_function))
 843                                die(_("Error in object"));
 844                        if (fsck_walk(obj, mark_link, NULL))
 845                                die(_("Not all child objects of %s are reachable"), sha1_to_hex(obj->sha1));
 846
 847                        if (obj->type == OBJ_TREE) {
 848                                struct tree *item = (struct tree *) obj;
 849                                item->buffer = NULL;
 850                                obj->parsed = 0;
 851                        }
 852                        if (obj->type == OBJ_COMMIT) {
 853                                struct commit *commit = (struct commit *) obj;
 854                                if (detach_commit_buffer(commit, NULL) != data)
 855                                        die("BUG: parse_object_buffer transmogrified our buffer");
 856                        }
 857                        obj->flags |= FLAG_CHECKED;
 858                }
 859                read_unlock();
 860        }
 861
 862        free(new_data);
 863}
 864
 865/*
 866 * This function is part of find_unresolved_deltas(). There are two
 867 * walkers going in the opposite ways.
 868 *
 869 * The first one in find_unresolved_deltas() traverses down from
 870 * parent node to children, deflating nodes along the way. However,
 871 * memory for deflated nodes is limited by delta_base_cache_limit, so
 872 * at some point parent node's deflated content may be freed.
 873 *
 874 * The second walker is this function, which goes from current node up
 875 * to top parent if necessary to deflate the node. In normal
 876 * situation, its parent node would be already deflated, so it just
 877 * needs to apply delta.
 878 *
 879 * In the worst case scenario, parent node is no longer deflated because
 880 * we're running out of delta_base_cache_limit; we need to re-deflate
 881 * parents, possibly up to the top base.
 882 *
 883 * All deflated objects here are subject to be freed if we exceed
 884 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 885 * just need to make sure the last node is not freed.
 886 */
 887static void *get_base_data(struct base_data *c)
 888{
 889        if (!c->data) {
 890                struct object_entry *obj = c->obj;
 891                struct base_data **delta = NULL;
 892                int delta_nr = 0, delta_alloc = 0;
 893
 894                while (is_delta_type(c->obj->type) && !c->data) {
 895                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 896                        delta[delta_nr++] = c;
 897                        c = c->base;
 898                }
 899                if (!delta_nr) {
 900                        c->data = get_data_from_pack(obj);
 901                        c->size = obj->size;
 902                        get_thread_data()->base_cache_used += c->size;
 903                        prune_base_data(c);
 904                }
 905                for (; delta_nr > 0; delta_nr--) {
 906                        void *base, *raw;
 907                        c = delta[delta_nr - 1];
 908                        obj = c->obj;
 909                        base = get_base_data(c->base);
 910                        raw = get_data_from_pack(obj);
 911                        c->data = patch_delta(
 912                                base, c->base->size,
 913                                raw, obj->size,
 914                                &c->size);
 915                        free(raw);
 916                        if (!c->data)
 917                                bad_object(obj->idx.offset, _("failed to apply delta"));
 918                        get_thread_data()->base_cache_used += c->size;
 919                        prune_base_data(c);
 920                }
 921                free(delta);
 922        }
 923        return c->data;
 924}
 925
 926static void resolve_delta(struct object_entry *delta_obj,
 927                          struct base_data *base, struct base_data *result)
 928{
 929        void *base_data, *delta_data;
 930
 931        if (show_stat) {
 932                int i = delta_obj - objects;
 933                int j = base->obj - objects;
 934                obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 935                deepest_delta_lock();
 936                if (deepest_delta < obj_stat[i].delta_depth)
 937                        deepest_delta = obj_stat[i].delta_depth;
 938                deepest_delta_unlock();
 939                obj_stat[i].base_object_no = j;
 940        }
 941        delta_data = get_data_from_pack(delta_obj);
 942        base_data = get_base_data(base);
 943        result->obj = delta_obj;
 944        result->data = patch_delta(base_data, base->size,
 945                                   delta_data, delta_obj->size, &result->size);
 946        free(delta_data);
 947        if (!result->data)
 948                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 949        hash_sha1_file(result->data, result->size,
 950                       typename(delta_obj->real_type), delta_obj->idx.sha1);
 951        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 952                    delta_obj->idx.sha1);
 953        counter_lock();
 954        nr_resolved_deltas++;
 955        counter_unlock();
 956}
 957
 958/*
 959 * Standard boolean compare-and-swap: atomically check whether "*type" is
 960 * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 961 * and return false.
 962 */
 963static int compare_and_swap_type(signed char *type,
 964                                 enum object_type want,
 965                                 enum object_type set)
 966{
 967        enum object_type old;
 968
 969        type_cas_lock();
 970        old = *type;
 971        if (old == want)
 972                *type = set;
 973        type_cas_unlock();
 974
 975        return old == want;
 976}
 977
 978static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 979                                                  struct base_data *prev_base)
 980{
 981        if (base->ref_last == -1 && base->ofs_last == -1) {
 982                find_ref_delta_children(base->obj->idx.sha1,
 983                                        &base->ref_first, &base->ref_last,
 984                                        OBJ_REF_DELTA);
 985
 986                find_ofs_delta_children(base->obj->idx.offset,
 987                                        &base->ofs_first, &base->ofs_last,
 988                                        OBJ_OFS_DELTA);
 989
 990                if (base->ref_last == -1 && base->ofs_last == -1) {
 991                        free(base->data);
 992                        return NULL;
 993                }
 994
 995                link_base_data(prev_base, base);
 996        }
 997
 998        if (base->ref_first <= base->ref_last) {
 999                struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
1000                struct base_data *result = alloc_base_data();
1001
1002                if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
1003                                           base->obj->real_type))
1004                        die("BUG: child->real_type != OBJ_REF_DELTA");
1005
1006                resolve_delta(child, base, result);
1007                if (base->ref_first == base->ref_last && base->ofs_last == -1)
1008                        free_base_data(base);
1009
1010                base->ref_first++;
1011                return result;
1012        }
1013
1014        if (base->ofs_first <= base->ofs_last) {
1015                struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
1016                struct base_data *result = alloc_base_data();
1017
1018                assert(child->real_type == OBJ_OFS_DELTA);
1019                child->real_type = base->obj->real_type;
1020                resolve_delta(child, base, result);
1021                if (base->ofs_first == base->ofs_last)
1022                        free_base_data(base);
1023
1024                base->ofs_first++;
1025                return result;
1026        }
1027
1028        unlink_base_data(base);
1029        return NULL;
1030}
1031
1032static void find_unresolved_deltas(struct base_data *base)
1033{
1034        struct base_data *new_base, *prev_base = NULL;
1035        for (;;) {
1036                new_base = find_unresolved_deltas_1(base, prev_base);
1037
1038                if (new_base) {
1039                        prev_base = base;
1040                        base = new_base;
1041                } else {
1042                        free(base);
1043                        base = prev_base;
1044                        if (!base)
1045                                return;
1046                        prev_base = base->base;
1047                }
1048        }
1049}
1050
1051static int compare_ofs_delta_entry(const void *a, const void *b)
1052{
1053        const struct ofs_delta_entry *delta_a = a;
1054        const struct ofs_delta_entry *delta_b = b;
1055
1056        return delta_a->offset < delta_b->offset ? -1 :
1057               delta_a->offset > delta_b->offset ?  1 :
1058               0;
1059}
1060
1061static int compare_ref_delta_entry(const void *a, const void *b)
1062{
1063        const struct ref_delta_entry *delta_a = a;
1064        const struct ref_delta_entry *delta_b = b;
1065
1066        return hashcmp(delta_a->sha1, delta_b->sha1);
1067}
1068
1069static void resolve_base(struct object_entry *obj)
1070{
1071        struct base_data *base_obj = alloc_base_data();
1072        base_obj->obj = obj;
1073        base_obj->data = NULL;
1074        find_unresolved_deltas(base_obj);
1075}
1076
1077#ifndef NO_PTHREADS
1078static void *threaded_second_pass(void *data)
1079{
1080        set_thread_data(data);
1081        for (;;) {
1082                int i;
1083                counter_lock();
1084                display_progress(progress, nr_resolved_deltas);
1085                counter_unlock();
1086                work_lock();
1087                while (nr_dispatched < nr_objects &&
1088                       is_delta_type(objects[nr_dispatched].type))
1089                        nr_dispatched++;
1090                if (nr_dispatched >= nr_objects) {
1091                        work_unlock();
1092                        break;
1093                }
1094                i = nr_dispatched++;
1095                work_unlock();
1096
1097                resolve_base(&objects[i]);
1098        }
1099        return NULL;
1100}
1101#endif
1102
1103/*
1104 * First pass:
1105 * - find locations of all objects;
1106 * - calculate SHA1 of all non-delta objects;
1107 * - remember base (SHA1 or offset) for all deltas.
1108 */
1109static void parse_pack_objects(unsigned char *sha1)
1110{
1111        int i, nr_delays = 0;
1112        struct ofs_delta_entry *ofs_delta = ofs_deltas;
1113        unsigned char ref_delta_sha1[20];
1114        struct stat st;
1115
1116        if (verbose)
1117                progress = start_progress(
1118                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1119                                nr_objects);
1120        for (i = 0; i < nr_objects; i++) {
1121                struct object_entry *obj = &objects[i];
1122                void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1123                                              ref_delta_sha1, obj->idx.sha1);
1124                obj->real_type = obj->type;
1125                if (obj->type == OBJ_OFS_DELTA) {
1126                        nr_ofs_deltas++;
1127                        ofs_delta->obj_no = i;
1128                        ofs_delta++;
1129                } else if (obj->type == OBJ_REF_DELTA) {
1130                        ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1131                        hashcpy(ref_deltas[nr_ref_deltas].sha1, ref_delta_sha1);
1132                        ref_deltas[nr_ref_deltas].obj_no = i;
1133                        nr_ref_deltas++;
1134                } else if (!data) {
1135                        /* large blobs, check later */
1136                        obj->real_type = OBJ_BAD;
1137                        nr_delays++;
1138                } else
1139                        sha1_object(data, NULL, obj->size, obj->type, obj->idx.sha1);
1140                free(data);
1141                display_progress(progress, i+1);
1142        }
1143        objects[i].idx.offset = consumed_bytes;
1144        stop_progress(&progress);
1145
1146        /* Check pack integrity */
1147        flush();
1148        git_SHA1_Final(sha1, &input_ctx);
1149        if (hashcmp(fill(20), sha1))
1150                die(_("pack is corrupted (SHA1 mismatch)"));
1151        use(20);
1152
1153        /* If input_fd is a file, we should have reached its end now. */
1154        if (fstat(input_fd, &st))
1155                die_errno(_("cannot fstat packfile"));
1156        if (S_ISREG(st.st_mode) &&
1157                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1158                die(_("pack has junk at the end"));
1159
1160        for (i = 0; i < nr_objects; i++) {
1161                struct object_entry *obj = &objects[i];
1162                if (obj->real_type != OBJ_BAD)
1163                        continue;
1164                obj->real_type = obj->type;
1165                sha1_object(NULL, obj, obj->size, obj->type, obj->idx.sha1);
1166                nr_delays--;
1167        }
1168        if (nr_delays)
1169                die(_("confusion beyond insanity in parse_pack_objects()"));
1170}
1171
1172/*
1173 * Second pass:
1174 * - for all non-delta objects, look if it is used as a base for
1175 *   deltas;
1176 * - if used as a base, uncompress the object and apply all deltas,
1177 *   recursively checking if the resulting object is used as a base
1178 *   for some more deltas.
1179 */
1180static void resolve_deltas(void)
1181{
1182        int i;
1183
1184        if (!nr_ofs_deltas && !nr_ref_deltas)
1185                return;
1186
1187        /* Sort deltas by base SHA1/offset for fast searching */
1188        qsort(ofs_deltas, nr_ofs_deltas, sizeof(struct ofs_delta_entry),
1189              compare_ofs_delta_entry);
1190        qsort(ref_deltas, nr_ref_deltas, sizeof(struct ref_delta_entry),
1191              compare_ref_delta_entry);
1192
1193        if (verbose)
1194                progress = start_progress(_("Resolving deltas"),
1195                                          nr_ref_deltas + nr_ofs_deltas);
1196
1197#ifndef NO_PTHREADS
1198        nr_dispatched = 0;
1199        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1200                init_thread();
1201                for (i = 0; i < nr_threads; i++) {
1202                        int ret = pthread_create(&thread_data[i].thread, NULL,
1203                                                 threaded_second_pass, thread_data + i);
1204                        if (ret)
1205                                die(_("unable to create thread: %s"),
1206                                    strerror(ret));
1207                }
1208                for (i = 0; i < nr_threads; i++)
1209                        pthread_join(thread_data[i].thread, NULL);
1210                cleanup_thread();
1211                return;
1212        }
1213#endif
1214
1215        for (i = 0; i < nr_objects; i++) {
1216                struct object_entry *obj = &objects[i];
1217
1218                if (is_delta_type(obj->type))
1219                        continue;
1220                resolve_base(obj);
1221                display_progress(progress, nr_resolved_deltas);
1222        }
1223}
1224
1225/*
1226 * Third pass:
1227 * - append objects to convert thin pack to full pack if required
1228 * - write the final 20-byte SHA-1
1229 */
1230static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved);
1231static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
1232{
1233        if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1234                stop_progress(&progress);
1235                /* Flush remaining pack final 20-byte SHA1. */
1236                flush();
1237                return;
1238        }
1239
1240        if (fix_thin_pack) {
1241                struct sha1file *f;
1242                unsigned char read_sha1[20], tail_sha1[20];
1243                struct strbuf msg = STRBUF_INIT;
1244                int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1245                int nr_objects_initial = nr_objects;
1246                if (nr_unresolved <= 0)
1247                        die(_("confusion beyond insanity"));
1248                REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1249                memset(objects + nr_objects + 1, 0,
1250                       nr_unresolved * sizeof(*objects));
1251                f = sha1fd(output_fd, curr_pack);
1252                fix_unresolved_deltas(f, nr_unresolved);
1253                strbuf_addf(&msg, _("completed with %d local objects"),
1254                            nr_objects - nr_objects_initial);
1255                stop_progress_msg(&progress, msg.buf);
1256                strbuf_release(&msg);
1257                sha1close(f, tail_sha1, 0);
1258                hashcpy(read_sha1, pack_sha1);
1259                fixup_pack_header_footer(output_fd, pack_sha1,
1260                                         curr_pack, nr_objects,
1261                                         read_sha1, consumed_bytes-20);
1262                if (hashcmp(read_sha1, tail_sha1) != 0)
1263                        die(_("Unexpected tail checksum for %s "
1264                              "(disk corruption?)"), curr_pack);
1265        }
1266        if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1267                die(Q_("pack has %d unresolved delta",
1268                       "pack has %d unresolved deltas",
1269                       nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1270                    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1271}
1272
1273static int write_compressed(struct sha1file *f, void *in, unsigned int size)
1274{
1275        git_zstream stream;
1276        int status;
1277        unsigned char outbuf[4096];
1278
1279        git_deflate_init(&stream, zlib_compression_level);
1280        stream.next_in = in;
1281        stream.avail_in = size;
1282
1283        do {
1284                stream.next_out = outbuf;
1285                stream.avail_out = sizeof(outbuf);
1286                status = git_deflate(&stream, Z_FINISH);
1287                sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
1288        } while (status == Z_OK);
1289
1290        if (status != Z_STREAM_END)
1291                die(_("unable to deflate appended object (%d)"), status);
1292        size = stream.total_out;
1293        git_deflate_end(&stream);
1294        return size;
1295}
1296
1297static struct object_entry *append_obj_to_pack(struct sha1file *f,
1298                               const unsigned char *sha1, void *buf,
1299                               unsigned long size, enum object_type type)
1300{
1301        struct object_entry *obj = &objects[nr_objects++];
1302        unsigned char header[10];
1303        unsigned long s = size;
1304        int n = 0;
1305        unsigned char c = (type << 4) | (s & 15);
1306        s >>= 4;
1307        while (s) {
1308                header[n++] = c | 0x80;
1309                c = s & 0x7f;
1310                s >>= 7;
1311        }
1312        header[n++] = c;
1313        crc32_begin(f);
1314        sha1write(f, header, n);
1315        obj[0].size = size;
1316        obj[0].hdr_size = n;
1317        obj[0].type = type;
1318        obj[0].real_type = type;
1319        obj[1].idx.offset = obj[0].idx.offset + n;
1320        obj[1].idx.offset += write_compressed(f, buf, size);
1321        obj[0].idx.crc32 = crc32_end(f);
1322        sha1flush(f);
1323        hashcpy(obj->idx.sha1, sha1);
1324        return obj;
1325}
1326
1327static int delta_pos_compare(const void *_a, const void *_b)
1328{
1329        struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1330        struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1331        return a->obj_no - b->obj_no;
1332}
1333
1334static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
1335{
1336        struct ref_delta_entry **sorted_by_pos;
1337        int i, n = 0;
1338
1339        /*
1340         * Since many unresolved deltas may well be themselves base objects
1341         * for more unresolved deltas, we really want to include the
1342         * smallest number of base objects that would cover as much delta
1343         * as possible by picking the
1344         * trunc deltas first, allowing for other deltas to resolve without
1345         * additional base objects.  Since most base objects are to be found
1346         * before deltas depending on them, a good heuristic is to start
1347         * resolving deltas in the same order as their position in the pack.
1348         */
1349        sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
1350        for (i = 0; i < nr_ref_deltas; i++)
1351                sorted_by_pos[n++] = &ref_deltas[i];
1352        qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
1353
1354        for (i = 0; i < n; i++) {
1355                struct ref_delta_entry *d = sorted_by_pos[i];
1356                enum object_type type;
1357                struct base_data *base_obj = alloc_base_data();
1358
1359                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1360                        continue;
1361                base_obj->data = read_sha1_file(d->sha1, &type, &base_obj->size);
1362                if (!base_obj->data)
1363                        continue;
1364
1365                if (check_sha1_signature(d->sha1, base_obj->data,
1366                                base_obj->size, typename(type)))
1367                        die(_("local object %s is corrupt"), sha1_to_hex(d->sha1));
1368                base_obj->obj = append_obj_to_pack(f, d->sha1,
1369                                        base_obj->data, base_obj->size, type);
1370                find_unresolved_deltas(base_obj);
1371                display_progress(progress, nr_resolved_deltas);
1372        }
1373        free(sorted_by_pos);
1374}
1375
1376static void final(const char *final_pack_name, const char *curr_pack_name,
1377                  const char *final_index_name, const char *curr_index_name,
1378                  const char *keep_name, const char *keep_msg,
1379                  unsigned char *sha1)
1380{
1381        const char *report = "pack";
1382        char name[PATH_MAX];
1383        int err;
1384
1385        if (!from_stdin) {
1386                close(input_fd);
1387        } else {
1388                fsync_or_die(output_fd, curr_pack_name);
1389                err = close(output_fd);
1390                if (err)
1391                        die_errno(_("error while closing pack file"));
1392        }
1393
1394        if (keep_msg) {
1395                int keep_fd, keep_msg_len = strlen(keep_msg);
1396
1397                if (!keep_name)
1398                        keep_fd = odb_pack_keep(name, sizeof(name), sha1);
1399                else
1400                        keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
1401
1402                if (keep_fd < 0) {
1403                        if (errno != EEXIST)
1404                                die_errno(_("cannot write keep file '%s'"),
1405                                          keep_name ? keep_name : name);
1406                } else {
1407                        if (keep_msg_len > 0) {
1408                                write_or_die(keep_fd, keep_msg, keep_msg_len);
1409                                write_or_die(keep_fd, "\n", 1);
1410                        }
1411                        if (close(keep_fd) != 0)
1412                                die_errno(_("cannot close written keep file '%s'"),
1413                                          keep_name ? keep_name : name);
1414                        report = "keep";
1415                }
1416        }
1417
1418        if (final_pack_name != curr_pack_name) {
1419                if (!final_pack_name) {
1420                        snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
1421                                 get_object_directory(), sha1_to_hex(sha1));
1422                        final_pack_name = name;
1423                }
1424                if (move_temp_to_file(curr_pack_name, final_pack_name))
1425                        die(_("cannot store pack file"));
1426        } else if (from_stdin)
1427                chmod(final_pack_name, 0444);
1428
1429        if (final_index_name != curr_index_name) {
1430                if (!final_index_name) {
1431                        snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
1432                                 get_object_directory(), sha1_to_hex(sha1));
1433                        final_index_name = name;
1434                }
1435                if (move_temp_to_file(curr_index_name, final_index_name))
1436                        die(_("cannot store index file"));
1437        } else
1438                chmod(final_index_name, 0444);
1439
1440        if (!from_stdin) {
1441                printf("%s\n", sha1_to_hex(sha1));
1442        } else {
1443                char buf[48];
1444                int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
1445                                   report, sha1_to_hex(sha1));
1446                write_or_die(1, buf, len);
1447
1448                /*
1449                 * Let's just mimic git-unpack-objects here and write
1450                 * the last part of the input buffer to stdout.
1451                 */
1452                while (input_len) {
1453                        err = xwrite(1, input_buffer + input_offset, input_len);
1454                        if (err <= 0)
1455                                break;
1456                        input_len -= err;
1457                        input_offset += err;
1458                }
1459        }
1460}
1461
1462static int git_index_pack_config(const char *k, const char *v, void *cb)
1463{
1464        struct pack_idx_option *opts = cb;
1465
1466        if (!strcmp(k, "pack.indexversion")) {
1467                opts->version = git_config_int(k, v);
1468                if (opts->version > 2)
1469                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1470                return 0;
1471        }
1472        if (!strcmp(k, "pack.threads")) {
1473                nr_threads = git_config_int(k, v);
1474                if (nr_threads < 0)
1475                        die(_("invalid number of threads specified (%d)"),
1476                            nr_threads);
1477#ifdef NO_PTHREADS
1478                if (nr_threads != 1)
1479                        warning(_("no threads support, ignoring %s"), k);
1480                nr_threads = 1;
1481#endif
1482                return 0;
1483        }
1484        return git_default_config(k, v, cb);
1485}
1486
1487static int cmp_uint32(const void *a_, const void *b_)
1488{
1489        uint32_t a = *((uint32_t *)a_);
1490        uint32_t b = *((uint32_t *)b_);
1491
1492        return (a < b) ? -1 : (a != b);
1493}
1494
1495static void read_v2_anomalous_offsets(struct packed_git *p,
1496                                      struct pack_idx_option *opts)
1497{
1498        const uint32_t *idx1, *idx2;
1499        uint32_t i;
1500
1501        /* The address of the 4-byte offset table */
1502        idx1 = (((const uint32_t *)p->index_data)
1503                + 2 /* 8-byte header */
1504                + 256 /* fan out */
1505                + 5 * p->num_objects /* 20-byte SHA-1 table */
1506                + p->num_objects /* CRC32 table */
1507                );
1508
1509        /* The address of the 8-byte offset table */
1510        idx2 = idx1 + p->num_objects;
1511
1512        for (i = 0; i < p->num_objects; i++) {
1513                uint32_t off = ntohl(idx1[i]);
1514                if (!(off & 0x80000000))
1515                        continue;
1516                off = off & 0x7fffffff;
1517                if (idx2[off * 2])
1518                        continue;
1519                /*
1520                 * The real offset is ntohl(idx2[off * 2]) in high 4
1521                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1522                 * octets.  But idx2[off * 2] is Zero!!!
1523                 */
1524                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1525                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1526        }
1527
1528        if (1 < opts->anomaly_nr)
1529                qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
1530}
1531
1532static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1533{
1534        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1535
1536        if (!p)
1537                die(_("Cannot open existing pack file '%s'"), pack_name);
1538        if (open_pack_index(p))
1539                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1540
1541        /* Read the attributes from the existing idx file */
1542        opts->version = p->index_version;
1543
1544        if (opts->version == 2)
1545                read_v2_anomalous_offsets(p, opts);
1546
1547        /*
1548         * Get rid of the idx file as we do not need it anymore.
1549         * NEEDSWORK: extract this bit from free_pack_by_name() in
1550         * sha1_file.c, perhaps?  It shouldn't matter very much as we
1551         * know we haven't installed this pack (hence we never have
1552         * read anything from it).
1553         */
1554        close_pack_index(p);
1555        free(p);
1556}
1557
1558static void show_pack_info(int stat_only)
1559{
1560        int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1561        unsigned long *chain_histogram = NULL;
1562
1563        if (deepest_delta)
1564                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1565
1566        for (i = 0; i < nr_objects; i++) {
1567                struct object_entry *obj = &objects[i];
1568
1569                if (is_delta_type(obj->type))
1570                        chain_histogram[obj_stat[i].delta_depth - 1]++;
1571                if (stat_only)
1572                        continue;
1573                printf("%s %-6s %lu %lu %"PRIuMAX,
1574                       sha1_to_hex(obj->idx.sha1),
1575                       typename(obj->real_type), obj->size,
1576                       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1577                       (uintmax_t)obj->idx.offset);
1578                if (is_delta_type(obj->type)) {
1579                        struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1580                        printf(" %u %s", obj_stat[i].delta_depth, sha1_to_hex(bobj->idx.sha1));
1581                }
1582                putchar('\n');
1583        }
1584
1585        if (baseobjects)
1586                printf_ln(Q_("non delta: %d object",
1587                             "non delta: %d objects",
1588                             baseobjects),
1589                          baseobjects);
1590        for (i = 0; i < deepest_delta; i++) {
1591                if (!chain_histogram[i])
1592                        continue;
1593                printf_ln(Q_("chain length = %d: %lu object",
1594                             "chain length = %d: %lu objects",
1595                             chain_histogram[i]),
1596                          i + 1,
1597                          chain_histogram[i]);
1598        }
1599}
1600
1601int cmd_index_pack(int argc, const char **argv, const char *prefix)
1602{
1603        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1604        const char *curr_index;
1605        const char *index_name = NULL, *pack_name = NULL;
1606        const char *keep_name = NULL, *keep_msg = NULL;
1607        struct strbuf index_name_buf = STRBUF_INIT,
1608                      keep_name_buf = STRBUF_INIT;
1609        struct pack_idx_entry **idx_objects;
1610        struct pack_idx_option opts;
1611        unsigned char pack_sha1[20];
1612        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1613
1614        if (argc == 2 && !strcmp(argv[1], "-h"))
1615                usage(index_pack_usage);
1616
1617        check_replace_refs = 0;
1618
1619        reset_pack_idx_option(&opts);
1620        git_config(git_index_pack_config, &opts);
1621        if (prefix && chdir(prefix))
1622                die(_("Cannot come back to cwd"));
1623
1624        for (i = 1; i < argc; i++) {
1625                const char *arg = argv[i];
1626
1627                if (*arg == '-') {
1628                        if (!strcmp(arg, "--stdin")) {
1629                                from_stdin = 1;
1630                        } else if (!strcmp(arg, "--fix-thin")) {
1631                                fix_thin_pack = 1;
1632                        } else if (!strcmp(arg, "--strict")) {
1633                                strict = 1;
1634                                do_fsck_object = 1;
1635                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1636                                strict = 1;
1637                                check_self_contained_and_connected = 1;
1638                        } else if (!strcmp(arg, "--verify")) {
1639                                verify = 1;
1640                        } else if (!strcmp(arg, "--verify-stat")) {
1641                                verify = 1;
1642                                show_stat = 1;
1643                        } else if (!strcmp(arg, "--verify-stat-only")) {
1644                                verify = 1;
1645                                show_stat = 1;
1646                                stat_only = 1;
1647                        } else if (!strcmp(arg, "--keep")) {
1648                                keep_msg = "";
1649                        } else if (starts_with(arg, "--keep=")) {
1650                                keep_msg = arg + 7;
1651                        } else if (starts_with(arg, "--threads=")) {
1652                                char *end;
1653                                nr_threads = strtoul(arg+10, &end, 0);
1654                                if (!arg[10] || *end || nr_threads < 0)
1655                                        usage(index_pack_usage);
1656#ifdef NO_PTHREADS
1657                                if (nr_threads != 1)
1658                                        warning(_("no threads support, "
1659                                                  "ignoring %s"), arg);
1660                                nr_threads = 1;
1661#endif
1662                        } else if (starts_with(arg, "--pack_header=")) {
1663                                struct pack_header *hdr;
1664                                char *c;
1665
1666                                hdr = (struct pack_header *)input_buffer;
1667                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1668                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1669                                if (*c != ',')
1670                                        die(_("bad %s"), arg);
1671                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1672                                if (*c)
1673                                        die(_("bad %s"), arg);
1674                                input_len = sizeof(*hdr);
1675                        } else if (!strcmp(arg, "-v")) {
1676                                verbose = 1;
1677                        } else if (!strcmp(arg, "-o")) {
1678                                if (index_name || (i+1) >= argc)
1679                                        usage(index_pack_usage);
1680                                index_name = argv[++i];
1681                        } else if (starts_with(arg, "--index-version=")) {
1682                                char *c;
1683                                opts.version = strtoul(arg + 16, &c, 10);
1684                                if (opts.version > 2)
1685                                        die(_("bad %s"), arg);
1686                                if (*c == ',')
1687                                        opts.off32_limit = strtoul(c+1, &c, 0);
1688                                if (*c || opts.off32_limit & 0x80000000)
1689                                        die(_("bad %s"), arg);
1690                        } else
1691                                usage(index_pack_usage);
1692                        continue;
1693                }
1694
1695                if (pack_name)
1696                        usage(index_pack_usage);
1697                pack_name = arg;
1698        }
1699
1700        if (!pack_name && !from_stdin)
1701                usage(index_pack_usage);
1702        if (fix_thin_pack && !from_stdin)
1703                die(_("--fix-thin cannot be used without --stdin"));
1704        if (!index_name && pack_name) {
1705                size_t len;
1706                if (!strip_suffix(pack_name, ".pack", &len))
1707                        die(_("packfile name '%s' does not end with '.pack'"),
1708                            pack_name);
1709                strbuf_add(&index_name_buf, pack_name, len);
1710                strbuf_addstr(&index_name_buf, ".idx");
1711                index_name = index_name_buf.buf;
1712        }
1713        if (keep_msg && !keep_name && pack_name) {
1714                size_t len;
1715                if (!strip_suffix(pack_name, ".pack", &len))
1716                        die(_("packfile name '%s' does not end with '.pack'"),
1717                            pack_name);
1718                strbuf_add(&keep_name_buf, pack_name, len);
1719                strbuf_addstr(&keep_name_buf, ".idx");
1720                keep_name = keep_name_buf.buf;
1721        }
1722        if (verify) {
1723                if (!index_name)
1724                        die(_("--verify with no packfile name given"));
1725                read_idx_option(&opts, index_name);
1726                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1727        }
1728        if (strict)
1729                opts.flags |= WRITE_IDX_STRICT;
1730
1731#ifndef NO_PTHREADS
1732        if (!nr_threads) {
1733                nr_threads = online_cpus();
1734                /* An experiment showed that more threads does not mean faster */
1735                if (nr_threads > 3)
1736                        nr_threads = 3;
1737        }
1738#endif
1739
1740        curr_pack = open_pack_file(pack_name);
1741        parse_pack_header();
1742        objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
1743        if (show_stat)
1744                obj_stat = xcalloc(nr_objects + 1, sizeof(struct object_stat));
1745        ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
1746        parse_pack_objects(pack_sha1);
1747        resolve_deltas();
1748        conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1749        free(ofs_deltas);
1750        free(ref_deltas);
1751        if (strict)
1752                foreign_nr = check_objects();
1753
1754        if (show_stat)
1755                show_pack_info(stat_only);
1756
1757        idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
1758        for (i = 0; i < nr_objects; i++)
1759                idx_objects[i] = &objects[i].idx;
1760        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1761        free(idx_objects);
1762
1763        if (!verify)
1764                final(pack_name, curr_pack,
1765                      index_name, curr_index,
1766                      keep_name, keep_msg,
1767                      pack_sha1);
1768        else
1769                close(input_fd);
1770        free(objects);
1771        strbuf_release(&index_name_buf);
1772        strbuf_release(&keep_name_buf);
1773        if (pack_name == NULL)
1774                free((void *) curr_pack);
1775        if (index_name == NULL)
1776                free((void *) curr_index);
1777
1778        /*
1779         * Let the caller know this pack is not self contained
1780         */
1781        if (check_self_contained_and_connected && foreign_nr)
1782                return 1;
1783
1784        return 0;
1785}