builtin / index-pack.con commit Merge branch 'rs/maint-config-use-labs' into maint (e8c2351)
   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 int hdr_size;
  22        enum object_type type;
  23        enum object_type real_type;
  24        unsigned delta_depth;
  25        int base_object_no;
  26};
  27
  28union delta_base {
  29        unsigned char sha1[20];
  30        off_t offset;
  31};
  32
  33struct base_data {
  34        struct base_data *base;
  35        struct base_data *child;
  36        struct object_entry *obj;
  37        void *data;
  38        unsigned long size;
  39        int ref_first, ref_last;
  40        int ofs_first, ofs_last;
  41};
  42
  43struct thread_local {
  44#ifndef NO_PTHREADS
  45        pthread_t thread;
  46#endif
  47        struct base_data *base_cache;
  48        size_t base_cache_used;
  49        int pack_fd;
  50};
  51
  52/*
  53 * Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
  54 * to memcmp() only the first 20 bytes.
  55 */
  56#define UNION_BASE_SZ   20
  57
  58#define FLAG_LINK (1u<<20)
  59#define FLAG_CHECKED (1u<<21)
  60
  61struct delta_entry {
  62        union delta_base base;
  63        int obj_no;
  64};
  65
  66static struct object_entry *objects;
  67static struct delta_entry *deltas;
  68static struct thread_local nothread_data;
  69static int nr_objects;
  70static int nr_deltas;
  71static int nr_resolved_deltas;
  72static int nr_threads;
  73
  74static int from_stdin;
  75static int strict;
  76static int do_fsck_object;
  77static int verbose;
  78static int show_stat;
  79static int check_self_contained_and_connected;
  80
  81static struct progress *progress;
  82
  83/* We always read in 4kB chunks. */
  84static unsigned char input_buffer[4096];
  85static unsigned int input_offset, input_len;
  86static off_t consumed_bytes;
  87static unsigned deepest_delta;
  88static git_SHA_CTX input_ctx;
  89static uint32_t input_crc32;
  90static int input_fd, output_fd;
  91static const char *curr_pack;
  92
  93#ifndef NO_PTHREADS
  94
  95static struct thread_local *thread_data;
  96static int nr_dispatched;
  97static int threads_active;
  98
  99static pthread_mutex_t read_mutex;
 100#define read_lock()             lock_mutex(&read_mutex)
 101#define read_unlock()           unlock_mutex(&read_mutex)
 102
 103static pthread_mutex_t counter_mutex;
 104#define counter_lock()          lock_mutex(&counter_mutex)
 105#define counter_unlock()        unlock_mutex(&counter_mutex)
 106
 107static pthread_mutex_t work_mutex;
 108#define work_lock()             lock_mutex(&work_mutex)
 109#define work_unlock()           unlock_mutex(&work_mutex)
 110
 111static pthread_mutex_t deepest_delta_mutex;
 112#define deepest_delta_lock()    lock_mutex(&deepest_delta_mutex)
 113#define deepest_delta_unlock()  unlock_mutex(&deepest_delta_mutex)
 114
 115static pthread_mutex_t type_cas_mutex;
 116#define type_cas_lock()         lock_mutex(&type_cas_mutex)
 117#define type_cas_unlock()       unlock_mutex(&type_cas_mutex)
 118
 119static pthread_key_t key;
 120
 121static inline void lock_mutex(pthread_mutex_t *mutex)
 122{
 123        if (threads_active)
 124                pthread_mutex_lock(mutex);
 125}
 126
 127static inline void unlock_mutex(pthread_mutex_t *mutex)
 128{
 129        if (threads_active)
 130                pthread_mutex_unlock(mutex);
 131}
 132
 133/*
 134 * Mutex and conditional variable can't be statically-initialized on Windows.
 135 */
 136static void init_thread(void)
 137{
 138        int i;
 139        init_recursive_mutex(&read_mutex);
 140        pthread_mutex_init(&counter_mutex, NULL);
 141        pthread_mutex_init(&work_mutex, NULL);
 142        pthread_mutex_init(&type_cas_mutex, NULL);
 143        if (show_stat)
 144                pthread_mutex_init(&deepest_delta_mutex, NULL);
 145        pthread_key_create(&key, NULL);
 146        thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 147        for (i = 0; i < nr_threads; i++) {
 148                thread_data[i].pack_fd = open(curr_pack, O_RDONLY);
 149                if (thread_data[i].pack_fd == -1)
 150                        die_errno(_("unable to open %s"), curr_pack);
 151        }
 152
 153        threads_active = 1;
 154}
 155
 156static void cleanup_thread(void)
 157{
 158        int i;
 159        if (!threads_active)
 160                return;
 161        threads_active = 0;
 162        pthread_mutex_destroy(&read_mutex);
 163        pthread_mutex_destroy(&counter_mutex);
 164        pthread_mutex_destroy(&work_mutex);
 165        pthread_mutex_destroy(&type_cas_mutex);
 166        if (show_stat)
 167                pthread_mutex_destroy(&deepest_delta_mutex);
 168        for (i = 0; i < nr_threads; i++)
 169                close(thread_data[i].pack_fd);
 170        pthread_key_delete(key);
 171        free(thread_data);
 172}
 173
 174#else
 175
 176#define read_lock()
 177#define read_unlock()
 178
 179#define counter_lock()
 180#define counter_unlock()
 181
 182#define work_lock()
 183#define work_unlock()
 184
 185#define deepest_delta_lock()
 186#define deepest_delta_unlock()
 187
 188#define type_cas_lock()
 189#define type_cas_unlock()
 190
 191#endif
 192
 193
 194static int mark_link(struct object *obj, int type, void *data)
 195{
 196        if (!obj)
 197                return -1;
 198
 199        if (type != OBJ_ANY && obj->type != type)
 200                die(_("object type mismatch at %s"), sha1_to_hex(obj->sha1));
 201
 202        obj->flags |= FLAG_LINK;
 203        return 0;
 204}
 205
 206/* The content of each linked object must have been checked
 207   or it must be already present in the object database */
 208static unsigned check_object(struct object *obj)
 209{
 210        if (!obj)
 211                return 0;
 212
 213        if (!(obj->flags & FLAG_LINK))
 214                return 0;
 215
 216        if (!(obj->flags & FLAG_CHECKED)) {
 217                unsigned long size;
 218                int type = sha1_object_info(obj->sha1, &size);
 219                if (type <= 0)
 220                        die(_("did not receive expected object %s"),
 221                              sha1_to_hex(obj->sha1));
 222                if (type != obj->type)
 223                        die(_("object %s: expected type %s, found %s"),
 224                            sha1_to_hex(obj->sha1),
 225                            typename(obj->type), typename(type));
 226                obj->flags |= FLAG_CHECKED;
 227                return 1;
 228        }
 229
 230        return 0;
 231}
 232
 233static unsigned check_objects(void)
 234{
 235        unsigned i, max, foreign_nr = 0;
 236
 237        max = get_max_object_index();
 238        for (i = 0; i < max; i++)
 239                foreign_nr += check_object(get_indexed_object(i));
 240        return foreign_nr;
 241}
 242
 243
 244/* Discard current buffer used content. */
 245static void flush(void)
 246{
 247        if (input_offset) {
 248                if (output_fd >= 0)
 249                        write_or_die(output_fd, input_buffer, input_offset);
 250                git_SHA1_Update(&input_ctx, input_buffer, input_offset);
 251                memmove(input_buffer, input_buffer + input_offset, input_len);
 252                input_offset = 0;
 253        }
 254}
 255
 256/*
 257 * Make sure at least "min" bytes are available in the buffer, and
 258 * return the pointer to the buffer.
 259 */
 260static void *fill(int min)
 261{
 262        if (min <= input_len)
 263                return input_buffer + input_offset;
 264        if (min > sizeof(input_buffer))
 265                die(Q_("cannot fill %d byte",
 266                       "cannot fill %d bytes",
 267                       min),
 268                    min);
 269        flush();
 270        do {
 271                ssize_t ret = xread(input_fd, input_buffer + input_len,
 272                                sizeof(input_buffer) - input_len);
 273                if (ret <= 0) {
 274                        if (!ret)
 275                                die(_("early EOF"));
 276                        die_errno(_("read error on input"));
 277                }
 278                input_len += ret;
 279                if (from_stdin)
 280                        display_throughput(progress, consumed_bytes + input_len);
 281        } while (input_len < min);
 282        return input_buffer;
 283}
 284
 285static void use(int bytes)
 286{
 287        if (bytes > input_len)
 288                die(_("used more bytes than were available"));
 289        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 290        input_len -= bytes;
 291        input_offset += bytes;
 292
 293        /* make sure off_t is sufficiently large not to wrap */
 294        if (signed_add_overflows(consumed_bytes, bytes))
 295                die(_("pack too large for current definition of off_t"));
 296        consumed_bytes += bytes;
 297}
 298
 299static const char *open_pack_file(const char *pack_name)
 300{
 301        if (from_stdin) {
 302                input_fd = 0;
 303                if (!pack_name) {
 304                        static char tmp_file[PATH_MAX];
 305                        output_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
 306                                                "pack/tmp_pack_XXXXXX");
 307                        pack_name = xstrdup(tmp_file);
 308                } else
 309                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 310                if (output_fd < 0)
 311                        die_errno(_("unable to create '%s'"), pack_name);
 312                nothread_data.pack_fd = output_fd;
 313        } else {
 314                input_fd = open(pack_name, O_RDONLY);
 315                if (input_fd < 0)
 316                        die_errno(_("cannot open packfile '%s'"), pack_name);
 317                output_fd = -1;
 318                nothread_data.pack_fd = input_fd;
 319        }
 320        git_SHA1_Init(&input_ctx);
 321        return pack_name;
 322}
 323
 324static void parse_pack_header(void)
 325{
 326        struct pack_header *hdr = fill(sizeof(struct pack_header));
 327
 328        /* Header consistency check */
 329        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 330                die(_("pack signature mismatch"));
 331        if (!pack_version_ok(hdr->hdr_version))
 332                die(_("pack version %"PRIu32" unsupported"),
 333                        ntohl(hdr->hdr_version));
 334
 335        nr_objects = ntohl(hdr->hdr_entries);
 336        use(sizeof(struct pack_header));
 337}
 338
 339static NORETURN void bad_object(unsigned long offset, const char *format,
 340                       ...) __attribute__((format (printf, 2, 3)));
 341
 342static NORETURN void bad_object(unsigned long offset, const char *format, ...)
 343{
 344        va_list params;
 345        char buf[1024];
 346
 347        va_start(params, format);
 348        vsnprintf(buf, sizeof(buf), format, params);
 349        va_end(params);
 350        die(_("pack has bad object at offset %lu: %s"), offset, buf);
 351}
 352
 353static inline struct thread_local *get_thread_data(void)
 354{
 355#ifndef NO_PTHREADS
 356        if (threads_active)
 357                return pthread_getspecific(key);
 358        assert(!threads_active &&
 359               "This should only be reached when all threads are gone");
 360#endif
 361        return &nothread_data;
 362}
 363
 364#ifndef NO_PTHREADS
 365static void set_thread_data(struct thread_local *data)
 366{
 367        if (threads_active)
 368                pthread_setspecific(key, data);
 369}
 370#endif
 371
 372static struct base_data *alloc_base_data(void)
 373{
 374        struct base_data *base = xcalloc(1, sizeof(struct base_data));
 375        base->ref_last = -1;
 376        base->ofs_last = -1;
 377        return base;
 378}
 379
 380static void free_base_data(struct base_data *c)
 381{
 382        if (c->data) {
 383                free(c->data);
 384                c->data = NULL;
 385                get_thread_data()->base_cache_used -= c->size;
 386        }
 387}
 388
 389static void prune_base_data(struct base_data *retain)
 390{
 391        struct base_data *b;
 392        struct thread_local *data = get_thread_data();
 393        for (b = data->base_cache;
 394             data->base_cache_used > delta_base_cache_limit && b;
 395             b = b->child) {
 396                if (b->data && b != retain)
 397                        free_base_data(b);
 398        }
 399}
 400
 401static void link_base_data(struct base_data *base, struct base_data *c)
 402{
 403        if (base)
 404                base->child = c;
 405        else
 406                get_thread_data()->base_cache = c;
 407
 408        c->base = base;
 409        c->child = NULL;
 410        if (c->data)
 411                get_thread_data()->base_cache_used += c->size;
 412        prune_base_data(c);
 413}
 414
 415static void unlink_base_data(struct base_data *c)
 416{
 417        struct base_data *base = c->base;
 418        if (base)
 419                base->child = NULL;
 420        else
 421                get_thread_data()->base_cache = NULL;
 422        free_base_data(c);
 423}
 424
 425static int is_delta_type(enum object_type type)
 426{
 427        return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 428}
 429
 430static void *unpack_entry_data(unsigned long offset, unsigned long size,
 431                               enum object_type type, unsigned char *sha1)
 432{
 433        static char fixed_buf[8192];
 434        int status;
 435        git_zstream stream;
 436        void *buf;
 437        git_SHA_CTX c;
 438        char hdr[32];
 439        int hdrlen;
 440
 441        if (!is_delta_type(type)) {
 442                hdrlen = sprintf(hdr, "%s %lu", typename(type), size) + 1;
 443                git_SHA1_Init(&c);
 444                git_SHA1_Update(&c, hdr, hdrlen);
 445        } else
 446                sha1 = NULL;
 447        if (type == OBJ_BLOB && size > big_file_threshold)
 448                buf = fixed_buf;
 449        else
 450                buf = xmalloc(size);
 451
 452        memset(&stream, 0, sizeof(stream));
 453        git_inflate_init(&stream);
 454        stream.next_out = buf;
 455        stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 456
 457        do {
 458                unsigned char *last_out = stream.next_out;
 459                stream.next_in = fill(1);
 460                stream.avail_in = input_len;
 461                status = git_inflate(&stream, 0);
 462                use(input_len - stream.avail_in);
 463                if (sha1)
 464                        git_SHA1_Update(&c, last_out, stream.next_out - last_out);
 465                if (buf == fixed_buf) {
 466                        stream.next_out = buf;
 467                        stream.avail_out = sizeof(fixed_buf);
 468                }
 469        } while (status == Z_OK);
 470        if (stream.total_out != size || status != Z_STREAM_END)
 471                bad_object(offset, _("inflate returned %d"), status);
 472        git_inflate_end(&stream);
 473        if (sha1)
 474                git_SHA1_Final(sha1, &c);
 475        return buf == fixed_buf ? NULL : buf;
 476}
 477
 478static void *unpack_raw_entry(struct object_entry *obj,
 479                              union delta_base *delta_base,
 480                              unsigned char *sha1)
 481{
 482        unsigned char *p;
 483        unsigned long size, c;
 484        off_t base_offset;
 485        unsigned shift;
 486        void *data;
 487
 488        obj->idx.offset = consumed_bytes;
 489        input_crc32 = crc32(0, NULL, 0);
 490
 491        p = fill(1);
 492        c = *p;
 493        use(1);
 494        obj->type = (c >> 4) & 7;
 495        size = (c & 15);
 496        shift = 4;
 497        while (c & 0x80) {
 498                p = fill(1);
 499                c = *p;
 500                use(1);
 501                size += (c & 0x7f) << shift;
 502                shift += 7;
 503        }
 504        obj->size = size;
 505
 506        switch (obj->type) {
 507        case OBJ_REF_DELTA:
 508                hashcpy(delta_base->sha1, fill(20));
 509                use(20);
 510                break;
 511        case OBJ_OFS_DELTA:
 512                memset(delta_base, 0, sizeof(*delta_base));
 513                p = fill(1);
 514                c = *p;
 515                use(1);
 516                base_offset = c & 127;
 517                while (c & 128) {
 518                        base_offset += 1;
 519                        if (!base_offset || MSB(base_offset, 7))
 520                                bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 521                        p = fill(1);
 522                        c = *p;
 523                        use(1);
 524                        base_offset = (base_offset << 7) + (c & 127);
 525                }
 526                delta_base->offset = obj->idx.offset - base_offset;
 527                if (delta_base->offset <= 0 || delta_base->offset >= obj->idx.offset)
 528                        bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 529                break;
 530        case OBJ_COMMIT:
 531        case OBJ_TREE:
 532        case OBJ_BLOB:
 533        case OBJ_TAG:
 534                break;
 535        default:
 536                bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 537        }
 538        obj->hdr_size = consumed_bytes - obj->idx.offset;
 539
 540        data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, sha1);
 541        obj->idx.crc32 = input_crc32;
 542        return data;
 543}
 544
 545static void *unpack_data(struct object_entry *obj,
 546                         int (*consume)(const unsigned char *, unsigned long, void *),
 547                         void *cb_data)
 548{
 549        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 550        unsigned long len = obj[1].idx.offset - from;
 551        unsigned char *data, *inbuf;
 552        git_zstream stream;
 553        int status;
 554
 555        data = xmalloc(consume ? 64*1024 : obj->size);
 556        inbuf = xmalloc((len < 64*1024) ? len : 64*1024);
 557
 558        memset(&stream, 0, sizeof(stream));
 559        git_inflate_init(&stream);
 560        stream.next_out = data;
 561        stream.avail_out = consume ? 64*1024 : obj->size;
 562
 563        do {
 564                ssize_t n = (len < 64*1024) ? len : 64*1024;
 565                n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 566                if (n < 0)
 567                        die_errno(_("cannot pread pack file"));
 568                if (!n)
 569                        die(Q_("premature end of pack file, %lu byte missing",
 570                               "premature end of pack file, %lu bytes missing",
 571                               len),
 572                            len);
 573                from += n;
 574                len -= n;
 575                stream.next_in = inbuf;
 576                stream.avail_in = n;
 577                if (!consume)
 578                        status = git_inflate(&stream, 0);
 579                else {
 580                        do {
 581                                status = git_inflate(&stream, 0);
 582                                if (consume(data, stream.next_out - data, cb_data)) {
 583                                        free(inbuf);
 584                                        free(data);
 585                                        return NULL;
 586                                }
 587                                stream.next_out = data;
 588                                stream.avail_out = 64*1024;
 589                        } while (status == Z_OK && stream.avail_in);
 590                }
 591        } while (len && status == Z_OK && !stream.avail_in);
 592
 593        /* This has been inflated OK when first encountered, so... */
 594        if (status != Z_STREAM_END || stream.total_out != obj->size)
 595                die(_("serious inflate inconsistency"));
 596
 597        git_inflate_end(&stream);
 598        free(inbuf);
 599        if (consume) {
 600                free(data);
 601                data = NULL;
 602        }
 603        return data;
 604}
 605
 606static void *get_data_from_pack(struct object_entry *obj)
 607{
 608        return unpack_data(obj, NULL, NULL);
 609}
 610
 611static int compare_delta_bases(const union delta_base *base1,
 612                               const union delta_base *base2,
 613                               enum object_type type1,
 614                               enum object_type type2)
 615{
 616        int cmp = type1 - type2;
 617        if (cmp)
 618                return cmp;
 619        return memcmp(base1, base2, UNION_BASE_SZ);
 620}
 621
 622static int find_delta(const union delta_base *base, enum object_type type)
 623{
 624        int first = 0, last = nr_deltas;
 625
 626        while (first < last) {
 627                int next = (first + last) / 2;
 628                struct delta_entry *delta = &deltas[next];
 629                int cmp;
 630
 631                cmp = compare_delta_bases(base, &delta->base,
 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_delta_children(const union delta_base *base,
 645                                int *first_index, int *last_index,
 646                                enum object_type type)
 647{
 648        int first = find_delta(base, type);
 649        int last = first;
 650        int end = nr_deltas - 1;
 651
 652        if (first < 0) {
 653                *first_index = 0;
 654                *last_index = -1;
 655                return;
 656        }
 657        while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
 658                --first;
 659        while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
 660                ++last;
 661        *first_index = first;
 662        *last_index = last;
 663}
 664
 665struct compare_data {
 666        struct object_entry *entry;
 667        struct git_istream *st;
 668        unsigned char *buf;
 669        unsigned long buf_size;
 670};
 671
 672static int compare_objects(const unsigned char *buf, unsigned long size,
 673                           void *cb_data)
 674{
 675        struct compare_data *data = cb_data;
 676
 677        if (data->buf_size < size) {
 678                free(data->buf);
 679                data->buf = xmalloc(size);
 680                data->buf_size = size;
 681        }
 682
 683        while (size) {
 684                ssize_t len = read_istream(data->st, data->buf, size);
 685                if (len == 0)
 686                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 687                            sha1_to_hex(data->entry->idx.sha1));
 688                if (len < 0)
 689                        die(_("unable to read %s"),
 690                            sha1_to_hex(data->entry->idx.sha1));
 691                if (memcmp(buf, data->buf, len))
 692                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 693                            sha1_to_hex(data->entry->idx.sha1));
 694                size -= len;
 695                buf += len;
 696        }
 697        return 0;
 698}
 699
 700static int check_collison(struct object_entry *entry)
 701{
 702        struct compare_data data;
 703        enum object_type type;
 704        unsigned long size;
 705
 706        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 707                return -1;
 708
 709        memset(&data, 0, sizeof(data));
 710        data.entry = entry;
 711        data.st = open_istream(entry->idx.sha1, &type, &size, NULL);
 712        if (!data.st)
 713                return -1;
 714        if (size != entry->size || type != entry->type)
 715                die(_("SHA1 COLLISION FOUND WITH %s !"),
 716                    sha1_to_hex(entry->idx.sha1));
 717        unpack_data(entry, compare_objects, &data);
 718        close_istream(data.st);
 719        free(data.buf);
 720        return 0;
 721}
 722
 723static void sha1_object(const void *data, struct object_entry *obj_entry,
 724                        unsigned long size, enum object_type type,
 725                        const unsigned char *sha1)
 726{
 727        void *new_data = NULL;
 728        int collision_test_needed;
 729
 730        assert(data || obj_entry);
 731
 732        read_lock();
 733        collision_test_needed = has_sha1_file(sha1);
 734        read_unlock();
 735
 736        if (collision_test_needed && !data) {
 737                read_lock();
 738                if (!check_collison(obj_entry))
 739                        collision_test_needed = 0;
 740                read_unlock();
 741        }
 742        if (collision_test_needed) {
 743                void *has_data;
 744                enum object_type has_type;
 745                unsigned long has_size;
 746                read_lock();
 747                has_type = sha1_object_info(sha1, &has_size);
 748                if (has_type != type || has_size != size)
 749                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 750                has_data = read_sha1_file(sha1, &has_type, &has_size);
 751                read_unlock();
 752                if (!data)
 753                        data = new_data = get_data_from_pack(obj_entry);
 754                if (!has_data)
 755                        die(_("cannot read existing object %s"), sha1_to_hex(sha1));
 756                if (size != has_size || type != has_type ||
 757                    memcmp(data, has_data, size) != 0)
 758                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 759                free(has_data);
 760        }
 761
 762        if (strict) {
 763                read_lock();
 764                if (type == OBJ_BLOB) {
 765                        struct blob *blob = lookup_blob(sha1);
 766                        if (blob)
 767                                blob->object.flags |= FLAG_CHECKED;
 768                        else
 769                                die(_("invalid blob object %s"), sha1_to_hex(sha1));
 770                } else {
 771                        struct object *obj;
 772                        int eaten;
 773                        void *buf = (void *) data;
 774
 775                        assert(data && "data can only be NULL for large _blobs_");
 776
 777                        /*
 778                         * we do not need to free the memory here, as the
 779                         * buf is deleted by the caller.
 780                         */
 781                        obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 782                        if (!obj)
 783                                die(_("invalid %s"), typename(type));
 784                        if (do_fsck_object &&
 785                            fsck_object(obj, buf, size, 1,
 786                                    fsck_error_function))
 787                                die(_("Error in object"));
 788                        if (fsck_walk(obj, mark_link, NULL))
 789                                die(_("Not all child objects of %s are reachable"), sha1_to_hex(obj->sha1));
 790
 791                        if (obj->type == OBJ_TREE) {
 792                                struct tree *item = (struct tree *) obj;
 793                                item->buffer = NULL;
 794                                obj->parsed = 0;
 795                        }
 796                        if (obj->type == OBJ_COMMIT) {
 797                                struct commit *commit = (struct commit *) obj;
 798                                if (detach_commit_buffer(commit, NULL) != data)
 799                                        die("BUG: parse_object_buffer transmogrified our buffer");
 800                        }
 801                        obj->flags |= FLAG_CHECKED;
 802                }
 803                read_unlock();
 804        }
 805
 806        free(new_data);
 807}
 808
 809/*
 810 * This function is part of find_unresolved_deltas(). There are two
 811 * walkers going in the opposite ways.
 812 *
 813 * The first one in find_unresolved_deltas() traverses down from
 814 * parent node to children, deflating nodes along the way. However,
 815 * memory for deflated nodes is limited by delta_base_cache_limit, so
 816 * at some point parent node's deflated content may be freed.
 817 *
 818 * The second walker is this function, which goes from current node up
 819 * to top parent if necessary to deflate the node. In normal
 820 * situation, its parent node would be already deflated, so it just
 821 * needs to apply delta.
 822 *
 823 * In the worst case scenario, parent node is no longer deflated because
 824 * we're running out of delta_base_cache_limit; we need to re-deflate
 825 * parents, possibly up to the top base.
 826 *
 827 * All deflated objects here are subject to be freed if we exceed
 828 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 829 * just need to make sure the last node is not freed.
 830 */
 831static void *get_base_data(struct base_data *c)
 832{
 833        if (!c->data) {
 834                struct object_entry *obj = c->obj;
 835                struct base_data **delta = NULL;
 836                int delta_nr = 0, delta_alloc = 0;
 837
 838                while (is_delta_type(c->obj->type) && !c->data) {
 839                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 840                        delta[delta_nr++] = c;
 841                        c = c->base;
 842                }
 843                if (!delta_nr) {
 844                        c->data = get_data_from_pack(obj);
 845                        c->size = obj->size;
 846                        get_thread_data()->base_cache_used += c->size;
 847                        prune_base_data(c);
 848                }
 849                for (; delta_nr > 0; delta_nr--) {
 850                        void *base, *raw;
 851                        c = delta[delta_nr - 1];
 852                        obj = c->obj;
 853                        base = get_base_data(c->base);
 854                        raw = get_data_from_pack(obj);
 855                        c->data = patch_delta(
 856                                base, c->base->size,
 857                                raw, obj->size,
 858                                &c->size);
 859                        free(raw);
 860                        if (!c->data)
 861                                bad_object(obj->idx.offset, _("failed to apply delta"));
 862                        get_thread_data()->base_cache_used += c->size;
 863                        prune_base_data(c);
 864                }
 865                free(delta);
 866        }
 867        return c->data;
 868}
 869
 870static void resolve_delta(struct object_entry *delta_obj,
 871                          struct base_data *base, struct base_data *result)
 872{
 873        void *base_data, *delta_data;
 874
 875        if (show_stat) {
 876                delta_obj->delta_depth = base->obj->delta_depth + 1;
 877                deepest_delta_lock();
 878                if (deepest_delta < delta_obj->delta_depth)
 879                        deepest_delta = delta_obj->delta_depth;
 880                deepest_delta_unlock();
 881        }
 882        delta_obj->base_object_no = base->obj - objects;
 883        delta_data = get_data_from_pack(delta_obj);
 884        base_data = get_base_data(base);
 885        result->obj = delta_obj;
 886        result->data = patch_delta(base_data, base->size,
 887                                   delta_data, delta_obj->size, &result->size);
 888        free(delta_data);
 889        if (!result->data)
 890                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 891        hash_sha1_file(result->data, result->size,
 892                       typename(delta_obj->real_type), delta_obj->idx.sha1);
 893        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 894                    delta_obj->idx.sha1);
 895        counter_lock();
 896        nr_resolved_deltas++;
 897        counter_unlock();
 898}
 899
 900/*
 901 * Standard boolean compare-and-swap: atomically check whether "*type" is
 902 * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 903 * and return false.
 904 */
 905static int compare_and_swap_type(enum object_type *type,
 906                                 enum object_type want,
 907                                 enum object_type set)
 908{
 909        enum object_type old;
 910
 911        type_cas_lock();
 912        old = *type;
 913        if (old == want)
 914                *type = set;
 915        type_cas_unlock();
 916
 917        return old == want;
 918}
 919
 920static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 921                                                  struct base_data *prev_base)
 922{
 923        if (base->ref_last == -1 && base->ofs_last == -1) {
 924                union delta_base base_spec;
 925
 926                hashcpy(base_spec.sha1, base->obj->idx.sha1);
 927                find_delta_children(&base_spec,
 928                                    &base->ref_first, &base->ref_last, OBJ_REF_DELTA);
 929
 930                memset(&base_spec, 0, sizeof(base_spec));
 931                base_spec.offset = base->obj->idx.offset;
 932                find_delta_children(&base_spec,
 933                                    &base->ofs_first, &base->ofs_last, OBJ_OFS_DELTA);
 934
 935                if (base->ref_last == -1 && base->ofs_last == -1) {
 936                        free(base->data);
 937                        return NULL;
 938                }
 939
 940                link_base_data(prev_base, base);
 941        }
 942
 943        if (base->ref_first <= base->ref_last) {
 944                struct object_entry *child = objects + deltas[base->ref_first].obj_no;
 945                struct base_data *result = alloc_base_data();
 946
 947                if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
 948                                           base->obj->real_type))
 949                        die("BUG: child->real_type != OBJ_REF_DELTA");
 950
 951                resolve_delta(child, base, result);
 952                if (base->ref_first == base->ref_last && base->ofs_last == -1)
 953                        free_base_data(base);
 954
 955                base->ref_first++;
 956                return result;
 957        }
 958
 959        if (base->ofs_first <= base->ofs_last) {
 960                struct object_entry *child = objects + deltas[base->ofs_first].obj_no;
 961                struct base_data *result = alloc_base_data();
 962
 963                assert(child->real_type == OBJ_OFS_DELTA);
 964                child->real_type = base->obj->real_type;
 965                resolve_delta(child, base, result);
 966                if (base->ofs_first == base->ofs_last)
 967                        free_base_data(base);
 968
 969                base->ofs_first++;
 970                return result;
 971        }
 972
 973        unlink_base_data(base);
 974        return NULL;
 975}
 976
 977static void find_unresolved_deltas(struct base_data *base)
 978{
 979        struct base_data *new_base, *prev_base = NULL;
 980        for (;;) {
 981                new_base = find_unresolved_deltas_1(base, prev_base);
 982
 983                if (new_base) {
 984                        prev_base = base;
 985                        base = new_base;
 986                } else {
 987                        free(base);
 988                        base = prev_base;
 989                        if (!base)
 990                                return;
 991                        prev_base = base->base;
 992                }
 993        }
 994}
 995
 996static int compare_delta_entry(const void *a, const void *b)
 997{
 998        const struct delta_entry *delta_a = a;
 999        const struct delta_entry *delta_b = b;
1000
1001        /* group by type (ref vs ofs) and then by value (sha-1 or offset) */
1002        return compare_delta_bases(&delta_a->base, &delta_b->base,
1003                                   objects[delta_a->obj_no].type,
1004                                   objects[delta_b->obj_no].type);
1005}
1006
1007static void resolve_base(struct object_entry *obj)
1008{
1009        struct base_data *base_obj = alloc_base_data();
1010        base_obj->obj = obj;
1011        base_obj->data = NULL;
1012        find_unresolved_deltas(base_obj);
1013}
1014
1015#ifndef NO_PTHREADS
1016static void *threaded_second_pass(void *data)
1017{
1018        set_thread_data(data);
1019        for (;;) {
1020                int i;
1021                counter_lock();
1022                display_progress(progress, nr_resolved_deltas);
1023                counter_unlock();
1024                work_lock();
1025                while (nr_dispatched < nr_objects &&
1026                       is_delta_type(objects[nr_dispatched].type))
1027                        nr_dispatched++;
1028                if (nr_dispatched >= nr_objects) {
1029                        work_unlock();
1030                        break;
1031                }
1032                i = nr_dispatched++;
1033                work_unlock();
1034
1035                resolve_base(&objects[i]);
1036        }
1037        return NULL;
1038}
1039#endif
1040
1041/*
1042 * First pass:
1043 * - find locations of all objects;
1044 * - calculate SHA1 of all non-delta objects;
1045 * - remember base (SHA1 or offset) for all deltas.
1046 */
1047static void parse_pack_objects(unsigned char *sha1)
1048{
1049        int i, nr_delays = 0;
1050        struct delta_entry *delta = deltas;
1051        struct stat st;
1052
1053        if (verbose)
1054                progress = start_progress(
1055                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1056                                nr_objects);
1057        for (i = 0; i < nr_objects; i++) {
1058                struct object_entry *obj = &objects[i];
1059                void *data = unpack_raw_entry(obj, &delta->base, obj->idx.sha1);
1060                obj->real_type = obj->type;
1061                if (is_delta_type(obj->type)) {
1062                        nr_deltas++;
1063                        delta->obj_no = i;
1064                        delta++;
1065                } else if (!data) {
1066                        /* large blobs, check later */
1067                        obj->real_type = OBJ_BAD;
1068                        nr_delays++;
1069                } else
1070                        sha1_object(data, NULL, obj->size, obj->type, obj->idx.sha1);
1071                free(data);
1072                display_progress(progress, i+1);
1073        }
1074        objects[i].idx.offset = consumed_bytes;
1075        stop_progress(&progress);
1076
1077        /* Check pack integrity */
1078        flush();
1079        git_SHA1_Final(sha1, &input_ctx);
1080        if (hashcmp(fill(20), sha1))
1081                die(_("pack is corrupted (SHA1 mismatch)"));
1082        use(20);
1083
1084        /* If input_fd is a file, we should have reached its end now. */
1085        if (fstat(input_fd, &st))
1086                die_errno(_("cannot fstat packfile"));
1087        if (S_ISREG(st.st_mode) &&
1088                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1089                die(_("pack has junk at the end"));
1090
1091        for (i = 0; i < nr_objects; i++) {
1092                struct object_entry *obj = &objects[i];
1093                if (obj->real_type != OBJ_BAD)
1094                        continue;
1095                obj->real_type = obj->type;
1096                sha1_object(NULL, obj, obj->size, obj->type, obj->idx.sha1);
1097                nr_delays--;
1098        }
1099        if (nr_delays)
1100                die(_("confusion beyond insanity in parse_pack_objects()"));
1101}
1102
1103/*
1104 * Second pass:
1105 * - for all non-delta objects, look if it is used as a base for
1106 *   deltas;
1107 * - if used as a base, uncompress the object and apply all deltas,
1108 *   recursively checking if the resulting object is used as a base
1109 *   for some more deltas.
1110 */
1111static void resolve_deltas(void)
1112{
1113        int i;
1114
1115        if (!nr_deltas)
1116                return;
1117
1118        /* Sort deltas by base SHA1/offset for fast searching */
1119        qsort(deltas, nr_deltas, sizeof(struct delta_entry),
1120              compare_delta_entry);
1121
1122        if (verbose)
1123                progress = start_progress(_("Resolving deltas"), nr_deltas);
1124
1125#ifndef NO_PTHREADS
1126        nr_dispatched = 0;
1127        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1128                init_thread();
1129                for (i = 0; i < nr_threads; i++) {
1130                        int ret = pthread_create(&thread_data[i].thread, NULL,
1131                                                 threaded_second_pass, thread_data + i);
1132                        if (ret)
1133                                die(_("unable to create thread: %s"),
1134                                    strerror(ret));
1135                }
1136                for (i = 0; i < nr_threads; i++)
1137                        pthread_join(thread_data[i].thread, NULL);
1138                cleanup_thread();
1139                return;
1140        }
1141#endif
1142
1143        for (i = 0; i < nr_objects; i++) {
1144                struct object_entry *obj = &objects[i];
1145
1146                if (is_delta_type(obj->type))
1147                        continue;
1148                resolve_base(obj);
1149                display_progress(progress, nr_resolved_deltas);
1150        }
1151}
1152
1153/*
1154 * Third pass:
1155 * - append objects to convert thin pack to full pack if required
1156 * - write the final 20-byte SHA-1
1157 */
1158static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved);
1159static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
1160{
1161        if (nr_deltas == nr_resolved_deltas) {
1162                stop_progress(&progress);
1163                /* Flush remaining pack final 20-byte SHA1. */
1164                flush();
1165                return;
1166        }
1167
1168        if (fix_thin_pack) {
1169                struct sha1file *f;
1170                unsigned char read_sha1[20], tail_sha1[20];
1171                struct strbuf msg = STRBUF_INIT;
1172                int nr_unresolved = nr_deltas - nr_resolved_deltas;
1173                int nr_objects_initial = nr_objects;
1174                if (nr_unresolved <= 0)
1175                        die(_("confusion beyond insanity"));
1176                REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1177                memset(objects + nr_objects + 1, 0,
1178                       nr_unresolved * sizeof(*objects));
1179                f = sha1fd(output_fd, curr_pack);
1180                fix_unresolved_deltas(f, nr_unresolved);
1181                strbuf_addf(&msg, _("completed with %d local objects"),
1182                            nr_objects - nr_objects_initial);
1183                stop_progress_msg(&progress, msg.buf);
1184                strbuf_release(&msg);
1185                sha1close(f, tail_sha1, 0);
1186                hashcpy(read_sha1, pack_sha1);
1187                fixup_pack_header_footer(output_fd, pack_sha1,
1188                                         curr_pack, nr_objects,
1189                                         read_sha1, consumed_bytes-20);
1190                if (hashcmp(read_sha1, tail_sha1) != 0)
1191                        die(_("Unexpected tail checksum for %s "
1192                              "(disk corruption?)"), curr_pack);
1193        }
1194        if (nr_deltas != nr_resolved_deltas)
1195                die(Q_("pack has %d unresolved delta",
1196                       "pack has %d unresolved deltas",
1197                       nr_deltas - nr_resolved_deltas),
1198                    nr_deltas - nr_resolved_deltas);
1199}
1200
1201static int write_compressed(struct sha1file *f, void *in, unsigned int size)
1202{
1203        git_zstream stream;
1204        int status;
1205        unsigned char outbuf[4096];
1206
1207        memset(&stream, 0, sizeof(stream));
1208        git_deflate_init(&stream, zlib_compression_level);
1209        stream.next_in = in;
1210        stream.avail_in = size;
1211
1212        do {
1213                stream.next_out = outbuf;
1214                stream.avail_out = sizeof(outbuf);
1215                status = git_deflate(&stream, Z_FINISH);
1216                sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
1217        } while (status == Z_OK);
1218
1219        if (status != Z_STREAM_END)
1220                die(_("unable to deflate appended object (%d)"), status);
1221        size = stream.total_out;
1222        git_deflate_end(&stream);
1223        return size;
1224}
1225
1226static struct object_entry *append_obj_to_pack(struct sha1file *f,
1227                               const unsigned char *sha1, void *buf,
1228                               unsigned long size, enum object_type type)
1229{
1230        struct object_entry *obj = &objects[nr_objects++];
1231        unsigned char header[10];
1232        unsigned long s = size;
1233        int n = 0;
1234        unsigned char c = (type << 4) | (s & 15);
1235        s >>= 4;
1236        while (s) {
1237                header[n++] = c | 0x80;
1238                c = s & 0x7f;
1239                s >>= 7;
1240        }
1241        header[n++] = c;
1242        crc32_begin(f);
1243        sha1write(f, header, n);
1244        obj[0].size = size;
1245        obj[0].hdr_size = n;
1246        obj[0].type = type;
1247        obj[0].real_type = type;
1248        obj[1].idx.offset = obj[0].idx.offset + n;
1249        obj[1].idx.offset += write_compressed(f, buf, size);
1250        obj[0].idx.crc32 = crc32_end(f);
1251        sha1flush(f);
1252        hashcpy(obj->idx.sha1, sha1);
1253        return obj;
1254}
1255
1256static int delta_pos_compare(const void *_a, const void *_b)
1257{
1258        struct delta_entry *a = *(struct delta_entry **)_a;
1259        struct delta_entry *b = *(struct delta_entry **)_b;
1260        return a->obj_no - b->obj_no;
1261}
1262
1263static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
1264{
1265        struct delta_entry **sorted_by_pos;
1266        int i, n = 0;
1267
1268        /*
1269         * Since many unresolved deltas may well be themselves base objects
1270         * for more unresolved deltas, we really want to include the
1271         * smallest number of base objects that would cover as much delta
1272         * as possible by picking the
1273         * trunc deltas first, allowing for other deltas to resolve without
1274         * additional base objects.  Since most base objects are to be found
1275         * before deltas depending on them, a good heuristic is to start
1276         * resolving deltas in the same order as their position in the pack.
1277         */
1278        sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
1279        for (i = 0; i < nr_deltas; i++) {
1280                if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
1281                        continue;
1282                sorted_by_pos[n++] = &deltas[i];
1283        }
1284        qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
1285
1286        for (i = 0; i < n; i++) {
1287                struct delta_entry *d = sorted_by_pos[i];
1288                enum object_type type;
1289                struct base_data *base_obj = alloc_base_data();
1290
1291                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1292                        continue;
1293                base_obj->data = read_sha1_file(d->base.sha1, &type, &base_obj->size);
1294                if (!base_obj->data)
1295                        continue;
1296
1297                if (check_sha1_signature(d->base.sha1, base_obj->data,
1298                                base_obj->size, typename(type)))
1299                        die(_("local object %s is corrupt"), sha1_to_hex(d->base.sha1));
1300                base_obj->obj = append_obj_to_pack(f, d->base.sha1,
1301                                        base_obj->data, base_obj->size, type);
1302                find_unresolved_deltas(base_obj);
1303                display_progress(progress, nr_resolved_deltas);
1304        }
1305        free(sorted_by_pos);
1306}
1307
1308static void final(const char *final_pack_name, const char *curr_pack_name,
1309                  const char *final_index_name, const char *curr_index_name,
1310                  const char *keep_name, const char *keep_msg,
1311                  unsigned char *sha1)
1312{
1313        const char *report = "pack";
1314        char name[PATH_MAX];
1315        int err;
1316
1317        if (!from_stdin) {
1318                close(input_fd);
1319        } else {
1320                fsync_or_die(output_fd, curr_pack_name);
1321                err = close(output_fd);
1322                if (err)
1323                        die_errno(_("error while closing pack file"));
1324        }
1325
1326        if (keep_msg) {
1327                int keep_fd, keep_msg_len = strlen(keep_msg);
1328
1329                if (!keep_name)
1330                        keep_fd = odb_pack_keep(name, sizeof(name), sha1);
1331                else
1332                        keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
1333
1334                if (keep_fd < 0) {
1335                        if (errno != EEXIST)
1336                                die_errno(_("cannot write keep file '%s'"),
1337                                          keep_name ? keep_name : name);
1338                } else {
1339                        if (keep_msg_len > 0) {
1340                                write_or_die(keep_fd, keep_msg, keep_msg_len);
1341                                write_or_die(keep_fd, "\n", 1);
1342                        }
1343                        if (close(keep_fd) != 0)
1344                                die_errno(_("cannot close written keep file '%s'"),
1345                                          keep_name ? keep_name : name);
1346                        report = "keep";
1347                }
1348        }
1349
1350        if (final_pack_name != curr_pack_name) {
1351                if (!final_pack_name) {
1352                        snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
1353                                 get_object_directory(), sha1_to_hex(sha1));
1354                        final_pack_name = name;
1355                }
1356                if (move_temp_to_file(curr_pack_name, final_pack_name))
1357                        die(_("cannot store pack file"));
1358        } else if (from_stdin)
1359                chmod(final_pack_name, 0444);
1360
1361        if (final_index_name != curr_index_name) {
1362                if (!final_index_name) {
1363                        snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
1364                                 get_object_directory(), sha1_to_hex(sha1));
1365                        final_index_name = name;
1366                }
1367                if (move_temp_to_file(curr_index_name, final_index_name))
1368                        die(_("cannot store index file"));
1369        } else
1370                chmod(final_index_name, 0444);
1371
1372        if (!from_stdin) {
1373                printf("%s\n", sha1_to_hex(sha1));
1374        } else {
1375                char buf[48];
1376                int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
1377                                   report, sha1_to_hex(sha1));
1378                write_or_die(1, buf, len);
1379
1380                /*
1381                 * Let's just mimic git-unpack-objects here and write
1382                 * the last part of the input buffer to stdout.
1383                 */
1384                while (input_len) {
1385                        err = xwrite(1, input_buffer + input_offset, input_len);
1386                        if (err <= 0)
1387                                break;
1388                        input_len -= err;
1389                        input_offset += err;
1390                }
1391        }
1392}
1393
1394static int git_index_pack_config(const char *k, const char *v, void *cb)
1395{
1396        struct pack_idx_option *opts = cb;
1397
1398        if (!strcmp(k, "pack.indexversion")) {
1399                opts->version = git_config_int(k, v);
1400                if (opts->version > 2)
1401                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1402                return 0;
1403        }
1404        if (!strcmp(k, "pack.threads")) {
1405                nr_threads = git_config_int(k, v);
1406                if (nr_threads < 0)
1407                        die(_("invalid number of threads specified (%d)"),
1408                            nr_threads);
1409#ifdef NO_PTHREADS
1410                if (nr_threads != 1)
1411                        warning(_("no threads support, ignoring %s"), k);
1412                nr_threads = 1;
1413#endif
1414                return 0;
1415        }
1416        return git_default_config(k, v, cb);
1417}
1418
1419static int cmp_uint32(const void *a_, const void *b_)
1420{
1421        uint32_t a = *((uint32_t *)a_);
1422        uint32_t b = *((uint32_t *)b_);
1423
1424        return (a < b) ? -1 : (a != b);
1425}
1426
1427static void read_v2_anomalous_offsets(struct packed_git *p,
1428                                      struct pack_idx_option *opts)
1429{
1430        const uint32_t *idx1, *idx2;
1431        uint32_t i;
1432
1433        /* The address of the 4-byte offset table */
1434        idx1 = (((const uint32_t *)p->index_data)
1435                + 2 /* 8-byte header */
1436                + 256 /* fan out */
1437                + 5 * p->num_objects /* 20-byte SHA-1 table */
1438                + p->num_objects /* CRC32 table */
1439                );
1440
1441        /* The address of the 8-byte offset table */
1442        idx2 = idx1 + p->num_objects;
1443
1444        for (i = 0; i < p->num_objects; i++) {
1445                uint32_t off = ntohl(idx1[i]);
1446                if (!(off & 0x80000000))
1447                        continue;
1448                off = off & 0x7fffffff;
1449                if (idx2[off * 2])
1450                        continue;
1451                /*
1452                 * The real offset is ntohl(idx2[off * 2]) in high 4
1453                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1454                 * octets.  But idx2[off * 2] is Zero!!!
1455                 */
1456                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1457                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1458        }
1459
1460        if (1 < opts->anomaly_nr)
1461                qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
1462}
1463
1464static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1465{
1466        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1467
1468        if (!p)
1469                die(_("Cannot open existing pack file '%s'"), pack_name);
1470        if (open_pack_index(p))
1471                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1472
1473        /* Read the attributes from the existing idx file */
1474        opts->version = p->index_version;
1475
1476        if (opts->version == 2)
1477                read_v2_anomalous_offsets(p, opts);
1478
1479        /*
1480         * Get rid of the idx file as we do not need it anymore.
1481         * NEEDSWORK: extract this bit from free_pack_by_name() in
1482         * sha1_file.c, perhaps?  It shouldn't matter very much as we
1483         * know we haven't installed this pack (hence we never have
1484         * read anything from it).
1485         */
1486        close_pack_index(p);
1487        free(p);
1488}
1489
1490static void show_pack_info(int stat_only)
1491{
1492        int i, baseobjects = nr_objects - nr_deltas;
1493        unsigned long *chain_histogram = NULL;
1494
1495        if (deepest_delta)
1496                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1497
1498        for (i = 0; i < nr_objects; i++) {
1499                struct object_entry *obj = &objects[i];
1500
1501                if (is_delta_type(obj->type))
1502                        chain_histogram[obj->delta_depth - 1]++;
1503                if (stat_only)
1504                        continue;
1505                printf("%s %-6s %lu %lu %"PRIuMAX,
1506                       sha1_to_hex(obj->idx.sha1),
1507                       typename(obj->real_type), obj->size,
1508                       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1509                       (uintmax_t)obj->idx.offset);
1510                if (is_delta_type(obj->type)) {
1511                        struct object_entry *bobj = &objects[obj->base_object_no];
1512                        printf(" %u %s", obj->delta_depth, sha1_to_hex(bobj->idx.sha1));
1513                }
1514                putchar('\n');
1515        }
1516
1517        if (baseobjects)
1518                printf_ln(Q_("non delta: %d object",
1519                             "non delta: %d objects",
1520                             baseobjects),
1521                          baseobjects);
1522        for (i = 0; i < deepest_delta; i++) {
1523                if (!chain_histogram[i])
1524                        continue;
1525                printf_ln(Q_("chain length = %d: %lu object",
1526                             "chain length = %d: %lu objects",
1527                             chain_histogram[i]),
1528                          i + 1,
1529                          chain_histogram[i]);
1530        }
1531}
1532
1533int cmd_index_pack(int argc, const char **argv, const char *prefix)
1534{
1535        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1536        const char *curr_index;
1537        const char *index_name = NULL, *pack_name = NULL;
1538        const char *keep_name = NULL, *keep_msg = NULL;
1539        struct strbuf index_name_buf = STRBUF_INIT,
1540                      keep_name_buf = STRBUF_INIT;
1541        struct pack_idx_entry **idx_objects;
1542        struct pack_idx_option opts;
1543        unsigned char pack_sha1[20];
1544        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1545
1546        if (argc == 2 && !strcmp(argv[1], "-h"))
1547                usage(index_pack_usage);
1548
1549        check_replace_refs = 0;
1550
1551        reset_pack_idx_option(&opts);
1552        git_config(git_index_pack_config, &opts);
1553        if (prefix && chdir(prefix))
1554                die(_("Cannot come back to cwd"));
1555
1556        for (i = 1; i < argc; i++) {
1557                const char *arg = argv[i];
1558
1559                if (*arg == '-') {
1560                        if (!strcmp(arg, "--stdin")) {
1561                                from_stdin = 1;
1562                        } else if (!strcmp(arg, "--fix-thin")) {
1563                                fix_thin_pack = 1;
1564                        } else if (!strcmp(arg, "--strict")) {
1565                                strict = 1;
1566                                do_fsck_object = 1;
1567                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1568                                strict = 1;
1569                                check_self_contained_and_connected = 1;
1570                        } else if (!strcmp(arg, "--verify")) {
1571                                verify = 1;
1572                        } else if (!strcmp(arg, "--verify-stat")) {
1573                                verify = 1;
1574                                show_stat = 1;
1575                        } else if (!strcmp(arg, "--verify-stat-only")) {
1576                                verify = 1;
1577                                show_stat = 1;
1578                                stat_only = 1;
1579                        } else if (!strcmp(arg, "--keep")) {
1580                                keep_msg = "";
1581                        } else if (starts_with(arg, "--keep=")) {
1582                                keep_msg = arg + 7;
1583                        } else if (starts_with(arg, "--threads=")) {
1584                                char *end;
1585                                nr_threads = strtoul(arg+10, &end, 0);
1586                                if (!arg[10] || *end || nr_threads < 0)
1587                                        usage(index_pack_usage);
1588#ifdef NO_PTHREADS
1589                                if (nr_threads != 1)
1590                                        warning(_("no threads support, "
1591                                                  "ignoring %s"), arg);
1592                                nr_threads = 1;
1593#endif
1594                        } else if (starts_with(arg, "--pack_header=")) {
1595                                struct pack_header *hdr;
1596                                char *c;
1597
1598                                hdr = (struct pack_header *)input_buffer;
1599                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1600                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1601                                if (*c != ',')
1602                                        die(_("bad %s"), arg);
1603                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1604                                if (*c)
1605                                        die(_("bad %s"), arg);
1606                                input_len = sizeof(*hdr);
1607                        } else if (!strcmp(arg, "-v")) {
1608                                verbose = 1;
1609                        } else if (!strcmp(arg, "-o")) {
1610                                if (index_name || (i+1) >= argc)
1611                                        usage(index_pack_usage);
1612                                index_name = argv[++i];
1613                        } else if (starts_with(arg, "--index-version=")) {
1614                                char *c;
1615                                opts.version = strtoul(arg + 16, &c, 10);
1616                                if (opts.version > 2)
1617                                        die(_("bad %s"), arg);
1618                                if (*c == ',')
1619                                        opts.off32_limit = strtoul(c+1, &c, 0);
1620                                if (*c || opts.off32_limit & 0x80000000)
1621                                        die(_("bad %s"), arg);
1622                        } else
1623                                usage(index_pack_usage);
1624                        continue;
1625                }
1626
1627                if (pack_name)
1628                        usage(index_pack_usage);
1629                pack_name = arg;
1630        }
1631
1632        if (!pack_name && !from_stdin)
1633                usage(index_pack_usage);
1634        if (fix_thin_pack && !from_stdin)
1635                die(_("--fix-thin cannot be used without --stdin"));
1636        if (!index_name && pack_name) {
1637                size_t len;
1638                if (!strip_suffix(pack_name, ".pack", &len))
1639                        die(_("packfile name '%s' does not end with '.pack'"),
1640                            pack_name);
1641                strbuf_add(&index_name_buf, pack_name, len);
1642                strbuf_addstr(&index_name_buf, ".idx");
1643                index_name = index_name_buf.buf;
1644        }
1645        if (keep_msg && !keep_name && pack_name) {
1646                size_t len;
1647                if (!strip_suffix(pack_name, ".pack", &len))
1648                        die(_("packfile name '%s' does not end with '.pack'"),
1649                            pack_name);
1650                strbuf_add(&keep_name_buf, pack_name, len);
1651                strbuf_addstr(&keep_name_buf, ".idx");
1652                keep_name = keep_name_buf.buf;
1653        }
1654        if (verify) {
1655                if (!index_name)
1656                        die(_("--verify with no packfile name given"));
1657                read_idx_option(&opts, index_name);
1658                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1659        }
1660        if (strict)
1661                opts.flags |= WRITE_IDX_STRICT;
1662
1663#ifndef NO_PTHREADS
1664        if (!nr_threads) {
1665                nr_threads = online_cpus();
1666                /* An experiment showed that more threads does not mean faster */
1667                if (nr_threads > 3)
1668                        nr_threads = 3;
1669        }
1670#endif
1671
1672        curr_pack = open_pack_file(pack_name);
1673        parse_pack_header();
1674        objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
1675        deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
1676        parse_pack_objects(pack_sha1);
1677        resolve_deltas();
1678        conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1679        free(deltas);
1680        if (strict)
1681                foreign_nr = check_objects();
1682
1683        if (show_stat)
1684                show_pack_info(stat_only);
1685
1686        idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
1687        for (i = 0; i < nr_objects; i++)
1688                idx_objects[i] = &objects[i].idx;
1689        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1690        free(idx_objects);
1691
1692        if (!verify)
1693                final(pack_name, curr_pack,
1694                      index_name, curr_index,
1695                      keep_name, keep_msg,
1696                      pack_sha1);
1697        else
1698                close(input_fd);
1699        free(objects);
1700        strbuf_release(&index_name_buf);
1701        strbuf_release(&keep_name_buf);
1702        if (pack_name == NULL)
1703                free((void *) curr_pack);
1704        if (index_name == NULL)
1705                free((void *) curr_index);
1706
1707        /*
1708         * Let the caller know this pack is not self contained
1709         */
1710        if (check_self_contained_and_connected && foreign_nr)
1711                return 1;
1712
1713        return 0;
1714}