builtin / index-pack.con commit lockfile: add accessor get_lock_file_path() (b4fb09e)
   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;
 620}
 621
 622static int find_ofs_delta(const off_t offset, enum object_type type)
 623{
 624        int first = 0, last = nr_ofs_deltas;
 625
 626        while (first < last) {
 627                int next = (first + last) / 2;
 628                struct ofs_delta_entry *delta = &ofs_deltas[next];
 629                int cmp;
 630
 631                cmp = compare_ofs_delta_bases(offset, delta->offset,
 632                                              type, objects[delta->obj_no].type);
 633                if (!cmp)
 634                        return next;
 635                if (cmp < 0) {
 636                        last = next;
 637                        continue;
 638                }
 639                first = next+1;
 640        }
 641        return -first-1;
 642}
 643
 644static void find_ofs_delta_children(off_t offset,
 645                                    int *first_index, int *last_index,
 646                                    enum object_type type)
 647{
 648        int first = find_ofs_delta(offset, type);
 649        int last = first;
 650        int end = nr_ofs_deltas - 1;
 651
 652        if (first < 0) {
 653                *first_index = 0;
 654                *last_index = -1;
 655                return;
 656        }
 657        while (first > 0 && ofs_deltas[first - 1].offset == offset)
 658                --first;
 659        while (last < end && ofs_deltas[last + 1].offset == offset)
 660                ++last;
 661        *first_index = first;
 662        *last_index = last;
 663}
 664
 665static int compare_ref_delta_bases(const unsigned char *sha1,
 666                                   const unsigned char *sha2,
 667                                   enum object_type type1,
 668                                   enum object_type type2)
 669{
 670        int cmp = type1 - type2;
 671        if (cmp)
 672                return cmp;
 673        return hashcmp(sha1, sha2);
 674}
 675
 676static int find_ref_delta(const unsigned char *sha1, enum object_type type)
 677{
 678        int first = 0, last = nr_ref_deltas;
 679
 680        while (first < last) {
 681                int next = (first + last) / 2;
 682                struct ref_delta_entry *delta = &ref_deltas[next];
 683                int cmp;
 684
 685                cmp = compare_ref_delta_bases(sha1, delta->sha1,
 686                                              type, objects[delta->obj_no].type);
 687                if (!cmp)
 688                        return next;
 689                if (cmp < 0) {
 690                        last = next;
 691                        continue;
 692                }
 693                first = next+1;
 694        }
 695        return -first-1;
 696}
 697
 698static void find_ref_delta_children(const unsigned char *sha1,
 699                                    int *first_index, int *last_index,
 700                                    enum object_type type)
 701{
 702        int first = find_ref_delta(sha1, type);
 703        int last = first;
 704        int end = nr_ref_deltas - 1;
 705
 706        if (first < 0) {
 707                *first_index = 0;
 708                *last_index = -1;
 709                return;
 710        }
 711        while (first > 0 && !hashcmp(ref_deltas[first - 1].sha1, sha1))
 712                --first;
 713        while (last < end && !hashcmp(ref_deltas[last + 1].sha1, sha1))
 714                ++last;
 715        *first_index = first;
 716        *last_index = last;
 717}
 718
 719struct compare_data {
 720        struct object_entry *entry;
 721        struct git_istream *st;
 722        unsigned char *buf;
 723        unsigned long buf_size;
 724};
 725
 726static int compare_objects(const unsigned char *buf, unsigned long size,
 727                           void *cb_data)
 728{
 729        struct compare_data *data = cb_data;
 730
 731        if (data->buf_size < size) {
 732                free(data->buf);
 733                data->buf = xmalloc(size);
 734                data->buf_size = size;
 735        }
 736
 737        while (size) {
 738                ssize_t len = read_istream(data->st, data->buf, size);
 739                if (len == 0)
 740                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 741                            sha1_to_hex(data->entry->idx.sha1));
 742                if (len < 0)
 743                        die(_("unable to read %s"),
 744                            sha1_to_hex(data->entry->idx.sha1));
 745                if (memcmp(buf, data->buf, len))
 746                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 747                            sha1_to_hex(data->entry->idx.sha1));
 748                size -= len;
 749                buf += len;
 750        }
 751        return 0;
 752}
 753
 754static int check_collison(struct object_entry *entry)
 755{
 756        struct compare_data data;
 757        enum object_type type;
 758        unsigned long size;
 759
 760        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 761                return -1;
 762
 763        memset(&data, 0, sizeof(data));
 764        data.entry = entry;
 765        data.st = open_istream(entry->idx.sha1, &type, &size, NULL);
 766        if (!data.st)
 767                return -1;
 768        if (size != entry->size || type != entry->type)
 769                die(_("SHA1 COLLISION FOUND WITH %s !"),
 770                    sha1_to_hex(entry->idx.sha1));
 771        unpack_data(entry, compare_objects, &data);
 772        close_istream(data.st);
 773        free(data.buf);
 774        return 0;
 775}
 776
 777static void sha1_object(const void *data, struct object_entry *obj_entry,
 778                        unsigned long size, enum object_type type,
 779                        const unsigned char *sha1)
 780{
 781        void *new_data = NULL;
 782        int collision_test_needed;
 783
 784        assert(data || obj_entry);
 785
 786        read_lock();
 787        collision_test_needed = has_sha1_file(sha1);
 788        read_unlock();
 789
 790        if (collision_test_needed && !data) {
 791                read_lock();
 792                if (!check_collison(obj_entry))
 793                        collision_test_needed = 0;
 794                read_unlock();
 795        }
 796        if (collision_test_needed) {
 797                void *has_data;
 798                enum object_type has_type;
 799                unsigned long has_size;
 800                read_lock();
 801                has_type = sha1_object_info(sha1, &has_size);
 802                if (has_type != type || has_size != size)
 803                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 804                has_data = read_sha1_file(sha1, &has_type, &has_size);
 805                read_unlock();
 806                if (!data)
 807                        data = new_data = get_data_from_pack(obj_entry);
 808                if (!has_data)
 809                        die(_("cannot read existing object %s"), sha1_to_hex(sha1));
 810                if (size != has_size || type != has_type ||
 811                    memcmp(data, has_data, size) != 0)
 812                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 813                free(has_data);
 814        }
 815
 816        if (strict) {
 817                read_lock();
 818                if (type == OBJ_BLOB) {
 819                        struct blob *blob = lookup_blob(sha1);
 820                        if (blob)
 821                                blob->object.flags |= FLAG_CHECKED;
 822                        else
 823                                die(_("invalid blob object %s"), sha1_to_hex(sha1));
 824                } else {
 825                        struct object *obj;
 826                        int eaten;
 827                        void *buf = (void *) data;
 828
 829                        assert(data && "data can only be NULL for large _blobs_");
 830
 831                        /*
 832                         * we do not need to free the memory here, as the
 833                         * buf is deleted by the caller.
 834                         */
 835                        obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 836                        if (!obj)
 837                                die(_("invalid %s"), typename(type));
 838                        if (do_fsck_object &&
 839                            fsck_object(obj, buf, size, 1,
 840                                    fsck_error_function))
 841                                die(_("Error in object"));
 842                        if (fsck_walk(obj, mark_link, NULL))
 843                                die(_("Not all child objects of %s are reachable"), sha1_to_hex(obj->sha1));
 844
 845                        if (obj->type == OBJ_TREE) {
 846                                struct tree *item = (struct tree *) obj;
 847                                item->buffer = NULL;
 848                                obj->parsed = 0;
 849                        }
 850                        if (obj->type == OBJ_COMMIT) {
 851                                struct commit *commit = (struct commit *) obj;
 852                                if (detach_commit_buffer(commit, NULL) != data)
 853                                        die("BUG: parse_object_buffer transmogrified our buffer");
 854                        }
 855                        obj->flags |= FLAG_CHECKED;
 856                }
 857                read_unlock();
 858        }
 859
 860        free(new_data);
 861}
 862
 863/*
 864 * This function is part of find_unresolved_deltas(). There are two
 865 * walkers going in the opposite ways.
 866 *
 867 * The first one in find_unresolved_deltas() traverses down from
 868 * parent node to children, deflating nodes along the way. However,
 869 * memory for deflated nodes is limited by delta_base_cache_limit, so
 870 * at some point parent node's deflated content may be freed.
 871 *
 872 * The second walker is this function, which goes from current node up
 873 * to top parent if necessary to deflate the node. In normal
 874 * situation, its parent node would be already deflated, so it just
 875 * needs to apply delta.
 876 *
 877 * In the worst case scenario, parent node is no longer deflated because
 878 * we're running out of delta_base_cache_limit; we need to re-deflate
 879 * parents, possibly up to the top base.
 880 *
 881 * All deflated objects here are subject to be freed if we exceed
 882 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 883 * just need to make sure the last node is not freed.
 884 */
 885static void *get_base_data(struct base_data *c)
 886{
 887        if (!c->data) {
 888                struct object_entry *obj = c->obj;
 889                struct base_data **delta = NULL;
 890                int delta_nr = 0, delta_alloc = 0;
 891
 892                while (is_delta_type(c->obj->type) && !c->data) {
 893                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 894                        delta[delta_nr++] = c;
 895                        c = c->base;
 896                }
 897                if (!delta_nr) {
 898                        c->data = get_data_from_pack(obj);
 899                        c->size = obj->size;
 900                        get_thread_data()->base_cache_used += c->size;
 901                        prune_base_data(c);
 902                }
 903                for (; delta_nr > 0; delta_nr--) {
 904                        void *base, *raw;
 905                        c = delta[delta_nr - 1];
 906                        obj = c->obj;
 907                        base = get_base_data(c->base);
 908                        raw = get_data_from_pack(obj);
 909                        c->data = patch_delta(
 910                                base, c->base->size,
 911                                raw, obj->size,
 912                                &c->size);
 913                        free(raw);
 914                        if (!c->data)
 915                                bad_object(obj->idx.offset, _("failed to apply delta"));
 916                        get_thread_data()->base_cache_used += c->size;
 917                        prune_base_data(c);
 918                }
 919                free(delta);
 920        }
 921        return c->data;
 922}
 923
 924static void resolve_delta(struct object_entry *delta_obj,
 925                          struct base_data *base, struct base_data *result)
 926{
 927        void *base_data, *delta_data;
 928
 929        if (show_stat) {
 930                int i = delta_obj - objects;
 931                int j = base->obj - objects;
 932                obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 933                deepest_delta_lock();
 934                if (deepest_delta < obj_stat[i].delta_depth)
 935                        deepest_delta = obj_stat[i].delta_depth;
 936                deepest_delta_unlock();
 937                obj_stat[i].base_object_no = j;
 938        }
 939        delta_data = get_data_from_pack(delta_obj);
 940        base_data = get_base_data(base);
 941        result->obj = delta_obj;
 942        result->data = patch_delta(base_data, base->size,
 943                                   delta_data, delta_obj->size, &result->size);
 944        free(delta_data);
 945        if (!result->data)
 946                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 947        hash_sha1_file(result->data, result->size,
 948                       typename(delta_obj->real_type), delta_obj->idx.sha1);
 949        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 950                    delta_obj->idx.sha1);
 951        counter_lock();
 952        nr_resolved_deltas++;
 953        counter_unlock();
 954}
 955
 956/*
 957 * Standard boolean compare-and-swap: atomically check whether "*type" is
 958 * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 959 * and return false.
 960 */
 961static int compare_and_swap_type(signed char *type,
 962                                 enum object_type want,
 963                                 enum object_type set)
 964{
 965        enum object_type old;
 966
 967        type_cas_lock();
 968        old = *type;
 969        if (old == want)
 970                *type = set;
 971        type_cas_unlock();
 972
 973        return old == want;
 974}
 975
 976static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 977                                                  struct base_data *prev_base)
 978{
 979        if (base->ref_last == -1 && base->ofs_last == -1) {
 980                find_ref_delta_children(base->obj->idx.sha1,
 981                                        &base->ref_first, &base->ref_last,
 982                                        OBJ_REF_DELTA);
 983
 984                find_ofs_delta_children(base->obj->idx.offset,
 985                                        &base->ofs_first, &base->ofs_last,
 986                                        OBJ_OFS_DELTA);
 987
 988                if (base->ref_last == -1 && base->ofs_last == -1) {
 989                        free(base->data);
 990                        return NULL;
 991                }
 992
 993                link_base_data(prev_base, base);
 994        }
 995
 996        if (base->ref_first <= base->ref_last) {
 997                struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
 998                struct base_data *result = alloc_base_data();
 999
1000                if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
1001                                           base->obj->real_type))
1002                        die("BUG: child->real_type != OBJ_REF_DELTA");
1003
1004                resolve_delta(child, base, result);
1005                if (base->ref_first == base->ref_last && base->ofs_last == -1)
1006                        free_base_data(base);
1007
1008                base->ref_first++;
1009                return result;
1010        }
1011
1012        if (base->ofs_first <= base->ofs_last) {
1013                struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
1014                struct base_data *result = alloc_base_data();
1015
1016                assert(child->real_type == OBJ_OFS_DELTA);
1017                child->real_type = base->obj->real_type;
1018                resolve_delta(child, base, result);
1019                if (base->ofs_first == base->ofs_last)
1020                        free_base_data(base);
1021
1022                base->ofs_first++;
1023                return result;
1024        }
1025
1026        unlink_base_data(base);
1027        return NULL;
1028}
1029
1030static void find_unresolved_deltas(struct base_data *base)
1031{
1032        struct base_data *new_base, *prev_base = NULL;
1033        for (;;) {
1034                new_base = find_unresolved_deltas_1(base, prev_base);
1035
1036                if (new_base) {
1037                        prev_base = base;
1038                        base = new_base;
1039                } else {
1040                        free(base);
1041                        base = prev_base;
1042                        if (!base)
1043                                return;
1044                        prev_base = base->base;
1045                }
1046        }
1047}
1048
1049static int compare_ofs_delta_entry(const void *a, const void *b)
1050{
1051        const struct ofs_delta_entry *delta_a = a;
1052        const struct ofs_delta_entry *delta_b = b;
1053
1054        return delta_a->offset - delta_b->offset;
1055}
1056
1057static int compare_ref_delta_entry(const void *a, const void *b)
1058{
1059        const struct ref_delta_entry *delta_a = a;
1060        const struct ref_delta_entry *delta_b = b;
1061
1062        return hashcmp(delta_a->sha1, delta_b->sha1);
1063}
1064
1065static void resolve_base(struct object_entry *obj)
1066{
1067        struct base_data *base_obj = alloc_base_data();
1068        base_obj->obj = obj;
1069        base_obj->data = NULL;
1070        find_unresolved_deltas(base_obj);
1071}
1072
1073#ifndef NO_PTHREADS
1074static void *threaded_second_pass(void *data)
1075{
1076        set_thread_data(data);
1077        for (;;) {
1078                int i;
1079                counter_lock();
1080                display_progress(progress, nr_resolved_deltas);
1081                counter_unlock();
1082                work_lock();
1083                while (nr_dispatched < nr_objects &&
1084                       is_delta_type(objects[nr_dispatched].type))
1085                        nr_dispatched++;
1086                if (nr_dispatched >= nr_objects) {
1087                        work_unlock();
1088                        break;
1089                }
1090                i = nr_dispatched++;
1091                work_unlock();
1092
1093                resolve_base(&objects[i]);
1094        }
1095        return NULL;
1096}
1097#endif
1098
1099/*
1100 * First pass:
1101 * - find locations of all objects;
1102 * - calculate SHA1 of all non-delta objects;
1103 * - remember base (SHA1 or offset) for all deltas.
1104 */
1105static void parse_pack_objects(unsigned char *sha1)
1106{
1107        int i, nr_delays = 0;
1108        struct ofs_delta_entry *ofs_delta = ofs_deltas;
1109        unsigned char ref_delta_sha1[20];
1110        struct stat st;
1111
1112        if (verbose)
1113                progress = start_progress(
1114                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1115                                nr_objects);
1116        for (i = 0; i < nr_objects; i++) {
1117                struct object_entry *obj = &objects[i];
1118                void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1119                                              ref_delta_sha1, obj->idx.sha1);
1120                obj->real_type = obj->type;
1121                if (obj->type == OBJ_OFS_DELTA) {
1122                        nr_ofs_deltas++;
1123                        ofs_delta->obj_no = i;
1124                        ofs_delta++;
1125                } else if (obj->type == OBJ_REF_DELTA) {
1126                        ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1127                        hashcpy(ref_deltas[nr_ref_deltas].sha1, ref_delta_sha1);
1128                        ref_deltas[nr_ref_deltas].obj_no = i;
1129                        nr_ref_deltas++;
1130                } else if (!data) {
1131                        /* large blobs, check later */
1132                        obj->real_type = OBJ_BAD;
1133                        nr_delays++;
1134                } else
1135                        sha1_object(data, NULL, obj->size, obj->type, obj->idx.sha1);
1136                free(data);
1137                display_progress(progress, i+1);
1138        }
1139        objects[i].idx.offset = consumed_bytes;
1140        stop_progress(&progress);
1141
1142        /* Check pack integrity */
1143        flush();
1144        git_SHA1_Final(sha1, &input_ctx);
1145        if (hashcmp(fill(20), sha1))
1146                die(_("pack is corrupted (SHA1 mismatch)"));
1147        use(20);
1148
1149        /* If input_fd is a file, we should have reached its end now. */
1150        if (fstat(input_fd, &st))
1151                die_errno(_("cannot fstat packfile"));
1152        if (S_ISREG(st.st_mode) &&
1153                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1154                die(_("pack has junk at the end"));
1155
1156        for (i = 0; i < nr_objects; i++) {
1157                struct object_entry *obj = &objects[i];
1158                if (obj->real_type != OBJ_BAD)
1159                        continue;
1160                obj->real_type = obj->type;
1161                sha1_object(NULL, obj, obj->size, obj->type, obj->idx.sha1);
1162                nr_delays--;
1163        }
1164        if (nr_delays)
1165                die(_("confusion beyond insanity in parse_pack_objects()"));
1166}
1167
1168/*
1169 * Second pass:
1170 * - for all non-delta objects, look if it is used as a base for
1171 *   deltas;
1172 * - if used as a base, uncompress the object and apply all deltas,
1173 *   recursively checking if the resulting object is used as a base
1174 *   for some more deltas.
1175 */
1176static void resolve_deltas(void)
1177{
1178        int i;
1179
1180        if (!nr_ofs_deltas && !nr_ref_deltas)
1181                return;
1182
1183        /* Sort deltas by base SHA1/offset for fast searching */
1184        qsort(ofs_deltas, nr_ofs_deltas, sizeof(struct ofs_delta_entry),
1185              compare_ofs_delta_entry);
1186        qsort(ref_deltas, nr_ref_deltas, sizeof(struct ref_delta_entry),
1187              compare_ref_delta_entry);
1188
1189        if (verbose)
1190                progress = start_progress(_("Resolving deltas"),
1191                                          nr_ref_deltas + nr_ofs_deltas);
1192
1193#ifndef NO_PTHREADS
1194        nr_dispatched = 0;
1195        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1196                init_thread();
1197                for (i = 0; i < nr_threads; i++) {
1198                        int ret = pthread_create(&thread_data[i].thread, NULL,
1199                                                 threaded_second_pass, thread_data + i);
1200                        if (ret)
1201                                die(_("unable to create thread: %s"),
1202                                    strerror(ret));
1203                }
1204                for (i = 0; i < nr_threads; i++)
1205                        pthread_join(thread_data[i].thread, NULL);
1206                cleanup_thread();
1207                return;
1208        }
1209#endif
1210
1211        for (i = 0; i < nr_objects; i++) {
1212                struct object_entry *obj = &objects[i];
1213
1214                if (is_delta_type(obj->type))
1215                        continue;
1216                resolve_base(obj);
1217                display_progress(progress, nr_resolved_deltas);
1218        }
1219}
1220
1221/*
1222 * Third pass:
1223 * - append objects to convert thin pack to full pack if required
1224 * - write the final 20-byte SHA-1
1225 */
1226static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved);
1227static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
1228{
1229        if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1230                stop_progress(&progress);
1231                /* Flush remaining pack final 20-byte SHA1. */
1232                flush();
1233                return;
1234        }
1235
1236        if (fix_thin_pack) {
1237                struct sha1file *f;
1238                unsigned char read_sha1[20], tail_sha1[20];
1239                struct strbuf msg = STRBUF_INIT;
1240                int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1241                int nr_objects_initial = nr_objects;
1242                if (nr_unresolved <= 0)
1243                        die(_("confusion beyond insanity"));
1244                REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1245                memset(objects + nr_objects + 1, 0,
1246                       nr_unresolved * sizeof(*objects));
1247                f = sha1fd(output_fd, curr_pack);
1248                fix_unresolved_deltas(f, nr_unresolved);
1249                strbuf_addf(&msg, _("completed with %d local objects"),
1250                            nr_objects - nr_objects_initial);
1251                stop_progress_msg(&progress, msg.buf);
1252                strbuf_release(&msg);
1253                sha1close(f, tail_sha1, 0);
1254                hashcpy(read_sha1, pack_sha1);
1255                fixup_pack_header_footer(output_fd, pack_sha1,
1256                                         curr_pack, nr_objects,
1257                                         read_sha1, consumed_bytes-20);
1258                if (hashcmp(read_sha1, tail_sha1) != 0)
1259                        die(_("Unexpected tail checksum for %s "
1260                              "(disk corruption?)"), curr_pack);
1261        }
1262        if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1263                die(Q_("pack has %d unresolved delta",
1264                       "pack has %d unresolved deltas",
1265                       nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1266                    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1267}
1268
1269static int write_compressed(struct sha1file *f, void *in, unsigned int size)
1270{
1271        git_zstream stream;
1272        int status;
1273        unsigned char outbuf[4096];
1274
1275        git_deflate_init(&stream, zlib_compression_level);
1276        stream.next_in = in;
1277        stream.avail_in = size;
1278
1279        do {
1280                stream.next_out = outbuf;
1281                stream.avail_out = sizeof(outbuf);
1282                status = git_deflate(&stream, Z_FINISH);
1283                sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
1284        } while (status == Z_OK);
1285
1286        if (status != Z_STREAM_END)
1287                die(_("unable to deflate appended object (%d)"), status);
1288        size = stream.total_out;
1289        git_deflate_end(&stream);
1290        return size;
1291}
1292
1293static struct object_entry *append_obj_to_pack(struct sha1file *f,
1294                               const unsigned char *sha1, void *buf,
1295                               unsigned long size, enum object_type type)
1296{
1297        struct object_entry *obj = &objects[nr_objects++];
1298        unsigned char header[10];
1299        unsigned long s = size;
1300        int n = 0;
1301        unsigned char c = (type << 4) | (s & 15);
1302        s >>= 4;
1303        while (s) {
1304                header[n++] = c | 0x80;
1305                c = s & 0x7f;
1306                s >>= 7;
1307        }
1308        header[n++] = c;
1309        crc32_begin(f);
1310        sha1write(f, header, n);
1311        obj[0].size = size;
1312        obj[0].hdr_size = n;
1313        obj[0].type = type;
1314        obj[0].real_type = type;
1315        obj[1].idx.offset = obj[0].idx.offset + n;
1316        obj[1].idx.offset += write_compressed(f, buf, size);
1317        obj[0].idx.crc32 = crc32_end(f);
1318        sha1flush(f);
1319        hashcpy(obj->idx.sha1, sha1);
1320        return obj;
1321}
1322
1323static int delta_pos_compare(const void *_a, const void *_b)
1324{
1325        struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1326        struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1327        return a->obj_no - b->obj_no;
1328}
1329
1330static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
1331{
1332        struct ref_delta_entry **sorted_by_pos;
1333        int i, n = 0;
1334
1335        /*
1336         * Since many unresolved deltas may well be themselves base objects
1337         * for more unresolved deltas, we really want to include the
1338         * smallest number of base objects that would cover as much delta
1339         * as possible by picking the
1340         * trunc deltas first, allowing for other deltas to resolve without
1341         * additional base objects.  Since most base objects are to be found
1342         * before deltas depending on them, a good heuristic is to start
1343         * resolving deltas in the same order as their position in the pack.
1344         */
1345        sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
1346        for (i = 0; i < nr_ref_deltas; i++)
1347                sorted_by_pos[n++] = &ref_deltas[i];
1348        qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
1349
1350        for (i = 0; i < n; i++) {
1351                struct ref_delta_entry *d = sorted_by_pos[i];
1352                enum object_type type;
1353                struct base_data *base_obj = alloc_base_data();
1354
1355                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1356                        continue;
1357                base_obj->data = read_sha1_file(d->sha1, &type, &base_obj->size);
1358                if (!base_obj->data)
1359                        continue;
1360
1361                if (check_sha1_signature(d->sha1, base_obj->data,
1362                                base_obj->size, typename(type)))
1363                        die(_("local object %s is corrupt"), sha1_to_hex(d->sha1));
1364                base_obj->obj = append_obj_to_pack(f, d->sha1,
1365                                        base_obj->data, base_obj->size, type);
1366                find_unresolved_deltas(base_obj);
1367                display_progress(progress, nr_resolved_deltas);
1368        }
1369        free(sorted_by_pos);
1370}
1371
1372static void final(const char *final_pack_name, const char *curr_pack_name,
1373                  const char *final_index_name, const char *curr_index_name,
1374                  const char *keep_name, const char *keep_msg,
1375                  unsigned char *sha1)
1376{
1377        const char *report = "pack";
1378        char name[PATH_MAX];
1379        int err;
1380
1381        if (!from_stdin) {
1382                close(input_fd);
1383        } else {
1384                fsync_or_die(output_fd, curr_pack_name);
1385                err = close(output_fd);
1386                if (err)
1387                        die_errno(_("error while closing pack file"));
1388        }
1389
1390        if (keep_msg) {
1391                int keep_fd, keep_msg_len = strlen(keep_msg);
1392
1393                if (!keep_name)
1394                        keep_fd = odb_pack_keep(name, sizeof(name), sha1);
1395                else
1396                        keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
1397
1398                if (keep_fd < 0) {
1399                        if (errno != EEXIST)
1400                                die_errno(_("cannot write keep file '%s'"),
1401                                          keep_name ? keep_name : name);
1402                } else {
1403                        if (keep_msg_len > 0) {
1404                                write_or_die(keep_fd, keep_msg, keep_msg_len);
1405                                write_or_die(keep_fd, "\n", 1);
1406                        }
1407                        if (close(keep_fd) != 0)
1408                                die_errno(_("cannot close written keep file '%s'"),
1409                                          keep_name ? keep_name : name);
1410                        report = "keep";
1411                }
1412        }
1413
1414        if (final_pack_name != curr_pack_name) {
1415                if (!final_pack_name) {
1416                        snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
1417                                 get_object_directory(), sha1_to_hex(sha1));
1418                        final_pack_name = name;
1419                }
1420                if (move_temp_to_file(curr_pack_name, final_pack_name))
1421                        die(_("cannot store pack file"));
1422        } else if (from_stdin)
1423                chmod(final_pack_name, 0444);
1424
1425        if (final_index_name != curr_index_name) {
1426                if (!final_index_name) {
1427                        snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
1428                                 get_object_directory(), sha1_to_hex(sha1));
1429                        final_index_name = name;
1430                }
1431                if (move_temp_to_file(curr_index_name, final_index_name))
1432                        die(_("cannot store index file"));
1433        } else
1434                chmod(final_index_name, 0444);
1435
1436        if (!from_stdin) {
1437                printf("%s\n", sha1_to_hex(sha1));
1438        } else {
1439                char buf[48];
1440                int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
1441                                   report, sha1_to_hex(sha1));
1442                write_or_die(1, buf, len);
1443
1444                /*
1445                 * Let's just mimic git-unpack-objects here and write
1446                 * the last part of the input buffer to stdout.
1447                 */
1448                while (input_len) {
1449                        err = xwrite(1, input_buffer + input_offset, input_len);
1450                        if (err <= 0)
1451                                break;
1452                        input_len -= err;
1453                        input_offset += err;
1454                }
1455        }
1456}
1457
1458static int git_index_pack_config(const char *k, const char *v, void *cb)
1459{
1460        struct pack_idx_option *opts = cb;
1461
1462        if (!strcmp(k, "pack.indexversion")) {
1463                opts->version = git_config_int(k, v);
1464                if (opts->version > 2)
1465                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1466                return 0;
1467        }
1468        if (!strcmp(k, "pack.threads")) {
1469                nr_threads = git_config_int(k, v);
1470                if (nr_threads < 0)
1471                        die(_("invalid number of threads specified (%d)"),
1472                            nr_threads);
1473#ifdef NO_PTHREADS
1474                if (nr_threads != 1)
1475                        warning(_("no threads support, ignoring %s"), k);
1476                nr_threads = 1;
1477#endif
1478                return 0;
1479        }
1480        return git_default_config(k, v, cb);
1481}
1482
1483static int cmp_uint32(const void *a_, const void *b_)
1484{
1485        uint32_t a = *((uint32_t *)a_);
1486        uint32_t b = *((uint32_t *)b_);
1487
1488        return (a < b) ? -1 : (a != b);
1489}
1490
1491static void read_v2_anomalous_offsets(struct packed_git *p,
1492                                      struct pack_idx_option *opts)
1493{
1494        const uint32_t *idx1, *idx2;
1495        uint32_t i;
1496
1497        /* The address of the 4-byte offset table */
1498        idx1 = (((const uint32_t *)p->index_data)
1499                + 2 /* 8-byte header */
1500                + 256 /* fan out */
1501                + 5 * p->num_objects /* 20-byte SHA-1 table */
1502                + p->num_objects /* CRC32 table */
1503                );
1504
1505        /* The address of the 8-byte offset table */
1506        idx2 = idx1 + p->num_objects;
1507
1508        for (i = 0; i < p->num_objects; i++) {
1509                uint32_t off = ntohl(idx1[i]);
1510                if (!(off & 0x80000000))
1511                        continue;
1512                off = off & 0x7fffffff;
1513                if (idx2[off * 2])
1514                        continue;
1515                /*
1516                 * The real offset is ntohl(idx2[off * 2]) in high 4
1517                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1518                 * octets.  But idx2[off * 2] is Zero!!!
1519                 */
1520                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1521                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1522        }
1523
1524        if (1 < opts->anomaly_nr)
1525                qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
1526}
1527
1528static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1529{
1530        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1531
1532        if (!p)
1533                die(_("Cannot open existing pack file '%s'"), pack_name);
1534        if (open_pack_index(p))
1535                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1536
1537        /* Read the attributes from the existing idx file */
1538        opts->version = p->index_version;
1539
1540        if (opts->version == 2)
1541                read_v2_anomalous_offsets(p, opts);
1542
1543        /*
1544         * Get rid of the idx file as we do not need it anymore.
1545         * NEEDSWORK: extract this bit from free_pack_by_name() in
1546         * sha1_file.c, perhaps?  It shouldn't matter very much as we
1547         * know we haven't installed this pack (hence we never have
1548         * read anything from it).
1549         */
1550        close_pack_index(p);
1551        free(p);
1552}
1553
1554static void show_pack_info(int stat_only)
1555{
1556        int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1557        unsigned long *chain_histogram = NULL;
1558
1559        if (deepest_delta)
1560                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1561
1562        for (i = 0; i < nr_objects; i++) {
1563                struct object_entry *obj = &objects[i];
1564
1565                if (is_delta_type(obj->type))
1566                        chain_histogram[obj_stat[i].delta_depth - 1]++;
1567                if (stat_only)
1568                        continue;
1569                printf("%s %-6s %lu %lu %"PRIuMAX,
1570                       sha1_to_hex(obj->idx.sha1),
1571                       typename(obj->real_type), obj->size,
1572                       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1573                       (uintmax_t)obj->idx.offset);
1574                if (is_delta_type(obj->type)) {
1575                        struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1576                        printf(" %u %s", obj_stat[i].delta_depth, sha1_to_hex(bobj->idx.sha1));
1577                }
1578                putchar('\n');
1579        }
1580
1581        if (baseobjects)
1582                printf_ln(Q_("non delta: %d object",
1583                             "non delta: %d objects",
1584                             baseobjects),
1585                          baseobjects);
1586        for (i = 0; i < deepest_delta; i++) {
1587                if (!chain_histogram[i])
1588                        continue;
1589                printf_ln(Q_("chain length = %d: %lu object",
1590                             "chain length = %d: %lu objects",
1591                             chain_histogram[i]),
1592                          i + 1,
1593                          chain_histogram[i]);
1594        }
1595}
1596
1597int cmd_index_pack(int argc, const char **argv, const char *prefix)
1598{
1599        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1600        const char *curr_index;
1601        const char *index_name = NULL, *pack_name = NULL;
1602        const char *keep_name = NULL, *keep_msg = NULL;
1603        struct strbuf index_name_buf = STRBUF_INIT,
1604                      keep_name_buf = STRBUF_INIT;
1605        struct pack_idx_entry **idx_objects;
1606        struct pack_idx_option opts;
1607        unsigned char pack_sha1[20];
1608        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1609
1610        if (argc == 2 && !strcmp(argv[1], "-h"))
1611                usage(index_pack_usage);
1612
1613        check_replace_refs = 0;
1614
1615        reset_pack_idx_option(&opts);
1616        git_config(git_index_pack_config, &opts);
1617        if (prefix && chdir(prefix))
1618                die(_("Cannot come back to cwd"));
1619
1620        for (i = 1; i < argc; i++) {
1621                const char *arg = argv[i];
1622
1623                if (*arg == '-') {
1624                        if (!strcmp(arg, "--stdin")) {
1625                                from_stdin = 1;
1626                        } else if (!strcmp(arg, "--fix-thin")) {
1627                                fix_thin_pack = 1;
1628                        } else if (!strcmp(arg, "--strict")) {
1629                                strict = 1;
1630                                do_fsck_object = 1;
1631                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1632                                strict = 1;
1633                                check_self_contained_and_connected = 1;
1634                        } else if (!strcmp(arg, "--verify")) {
1635                                verify = 1;
1636                        } else if (!strcmp(arg, "--verify-stat")) {
1637                                verify = 1;
1638                                show_stat = 1;
1639                        } else if (!strcmp(arg, "--verify-stat-only")) {
1640                                verify = 1;
1641                                show_stat = 1;
1642                                stat_only = 1;
1643                        } else if (!strcmp(arg, "--keep")) {
1644                                keep_msg = "";
1645                        } else if (starts_with(arg, "--keep=")) {
1646                                keep_msg = arg + 7;
1647                        } else if (starts_with(arg, "--threads=")) {
1648                                char *end;
1649                                nr_threads = strtoul(arg+10, &end, 0);
1650                                if (!arg[10] || *end || nr_threads < 0)
1651                                        usage(index_pack_usage);
1652#ifdef NO_PTHREADS
1653                                if (nr_threads != 1)
1654                                        warning(_("no threads support, "
1655                                                  "ignoring %s"), arg);
1656                                nr_threads = 1;
1657#endif
1658                        } else if (starts_with(arg, "--pack_header=")) {
1659                                struct pack_header *hdr;
1660                                char *c;
1661
1662                                hdr = (struct pack_header *)input_buffer;
1663                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1664                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1665                                if (*c != ',')
1666                                        die(_("bad %s"), arg);
1667                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1668                                if (*c)
1669                                        die(_("bad %s"), arg);
1670                                input_len = sizeof(*hdr);
1671                        } else if (!strcmp(arg, "-v")) {
1672                                verbose = 1;
1673                        } else if (!strcmp(arg, "-o")) {
1674                                if (index_name || (i+1) >= argc)
1675                                        usage(index_pack_usage);
1676                                index_name = argv[++i];
1677                        } else if (starts_with(arg, "--index-version=")) {
1678                                char *c;
1679                                opts.version = strtoul(arg + 16, &c, 10);
1680                                if (opts.version > 2)
1681                                        die(_("bad %s"), arg);
1682                                if (*c == ',')
1683                                        opts.off32_limit = strtoul(c+1, &c, 0);
1684                                if (*c || opts.off32_limit & 0x80000000)
1685                                        die(_("bad %s"), arg);
1686                        } else
1687                                usage(index_pack_usage);
1688                        continue;
1689                }
1690
1691                if (pack_name)
1692                        usage(index_pack_usage);
1693                pack_name = arg;
1694        }
1695
1696        if (!pack_name && !from_stdin)
1697                usage(index_pack_usage);
1698        if (fix_thin_pack && !from_stdin)
1699                die(_("--fix-thin cannot be used without --stdin"));
1700        if (!index_name && pack_name) {
1701                size_t len;
1702                if (!strip_suffix(pack_name, ".pack", &len))
1703                        die(_("packfile name '%s' does not end with '.pack'"),
1704                            pack_name);
1705                strbuf_add(&index_name_buf, pack_name, len);
1706                strbuf_addstr(&index_name_buf, ".idx");
1707                index_name = index_name_buf.buf;
1708        }
1709        if (keep_msg && !keep_name && pack_name) {
1710                size_t len;
1711                if (!strip_suffix(pack_name, ".pack", &len))
1712                        die(_("packfile name '%s' does not end with '.pack'"),
1713                            pack_name);
1714                strbuf_add(&keep_name_buf, pack_name, len);
1715                strbuf_addstr(&keep_name_buf, ".idx");
1716                keep_name = keep_name_buf.buf;
1717        }
1718        if (verify) {
1719                if (!index_name)
1720                        die(_("--verify with no packfile name given"));
1721                read_idx_option(&opts, index_name);
1722                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1723        }
1724        if (strict)
1725                opts.flags |= WRITE_IDX_STRICT;
1726
1727#ifndef NO_PTHREADS
1728        if (!nr_threads) {
1729                nr_threads = online_cpus();
1730                /* An experiment showed that more threads does not mean faster */
1731                if (nr_threads > 3)
1732                        nr_threads = 3;
1733        }
1734#endif
1735
1736        curr_pack = open_pack_file(pack_name);
1737        parse_pack_header();
1738        objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
1739        if (show_stat)
1740                obj_stat = xcalloc(nr_objects + 1, sizeof(struct object_stat));
1741        ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
1742        parse_pack_objects(pack_sha1);
1743        resolve_deltas();
1744        conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1745        free(ofs_deltas);
1746        free(ref_deltas);
1747        if (strict)
1748                foreign_nr = check_objects();
1749
1750        if (show_stat)
1751                show_pack_info(stat_only);
1752
1753        idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
1754        for (i = 0; i < nr_objects; i++)
1755                idx_objects[i] = &objects[i].idx;
1756        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1757        free(idx_objects);
1758
1759        if (!verify)
1760                final(pack_name, curr_pack,
1761                      index_name, curr_index,
1762                      keep_name, keep_msg,
1763                      pack_sha1);
1764        else
1765                close(input_fd);
1766        free(objects);
1767        strbuf_release(&index_name_buf);
1768        strbuf_release(&keep_name_buf);
1769        if (pack_name == NULL)
1770                free((void *) curr_pack);
1771        if (index_name == NULL)
1772                free((void *) curr_index);
1773
1774        /*
1775         * Let the caller know this pack is not self contained
1776         */
1777        if (check_self_contained_and_connected && foreign_nr)
1778                return 1;
1779
1780        return 0;
1781}