builtin / index-pack.con commit Merge branch 'nd/commit-p-doc' into maint (e2f1d2c)
   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 struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
  79static int verbose;
  80static int show_resolving_progress;
  81static int show_stat;
  82static int check_self_contained_and_connected;
  83
  84static struct progress *progress;
  85
  86/* We always read in 4kB chunks. */
  87static unsigned char input_buffer[4096];
  88static unsigned int input_offset, input_len;
  89static off_t consumed_bytes;
  90static unsigned deepest_delta;
  91static git_SHA_CTX input_ctx;
  92static uint32_t input_crc32;
  93static int input_fd, output_fd;
  94static const char *curr_pack;
  95
  96#ifndef NO_PTHREADS
  97
  98static struct thread_local *thread_data;
  99static int nr_dispatched;
 100static int threads_active;
 101
 102static pthread_mutex_t read_mutex;
 103#define read_lock()             lock_mutex(&read_mutex)
 104#define read_unlock()           unlock_mutex(&read_mutex)
 105
 106static pthread_mutex_t counter_mutex;
 107#define counter_lock()          lock_mutex(&counter_mutex)
 108#define counter_unlock()        unlock_mutex(&counter_mutex)
 109
 110static pthread_mutex_t work_mutex;
 111#define work_lock()             lock_mutex(&work_mutex)
 112#define work_unlock()           unlock_mutex(&work_mutex)
 113
 114static pthread_mutex_t deepest_delta_mutex;
 115#define deepest_delta_lock()    lock_mutex(&deepest_delta_mutex)
 116#define deepest_delta_unlock()  unlock_mutex(&deepest_delta_mutex)
 117
 118static pthread_mutex_t type_cas_mutex;
 119#define type_cas_lock()         lock_mutex(&type_cas_mutex)
 120#define type_cas_unlock()       unlock_mutex(&type_cas_mutex)
 121
 122static pthread_key_t key;
 123
 124static inline void lock_mutex(pthread_mutex_t *mutex)
 125{
 126        if (threads_active)
 127                pthread_mutex_lock(mutex);
 128}
 129
 130static inline void unlock_mutex(pthread_mutex_t *mutex)
 131{
 132        if (threads_active)
 133                pthread_mutex_unlock(mutex);
 134}
 135
 136/*
 137 * Mutex and conditional variable can't be statically-initialized on Windows.
 138 */
 139static void init_thread(void)
 140{
 141        int i;
 142        init_recursive_mutex(&read_mutex);
 143        pthread_mutex_init(&counter_mutex, NULL);
 144        pthread_mutex_init(&work_mutex, NULL);
 145        pthread_mutex_init(&type_cas_mutex, NULL);
 146        if (show_stat)
 147                pthread_mutex_init(&deepest_delta_mutex, NULL);
 148        pthread_key_create(&key, NULL);
 149        thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 150        for (i = 0; i < nr_threads; i++) {
 151                thread_data[i].pack_fd = open(curr_pack, O_RDONLY);
 152                if (thread_data[i].pack_fd == -1)
 153                        die_errno(_("unable to open %s"), curr_pack);
 154        }
 155
 156        threads_active = 1;
 157}
 158
 159static void cleanup_thread(void)
 160{
 161        int i;
 162        if (!threads_active)
 163                return;
 164        threads_active = 0;
 165        pthread_mutex_destroy(&read_mutex);
 166        pthread_mutex_destroy(&counter_mutex);
 167        pthread_mutex_destroy(&work_mutex);
 168        pthread_mutex_destroy(&type_cas_mutex);
 169        if (show_stat)
 170                pthread_mutex_destroy(&deepest_delta_mutex);
 171        for (i = 0; i < nr_threads; i++)
 172                close(thread_data[i].pack_fd);
 173        pthread_key_delete(key);
 174        free(thread_data);
 175}
 176
 177#else
 178
 179#define read_lock()
 180#define read_unlock()
 181
 182#define counter_lock()
 183#define counter_unlock()
 184
 185#define work_lock()
 186#define work_unlock()
 187
 188#define deepest_delta_lock()
 189#define deepest_delta_unlock()
 190
 191#define type_cas_lock()
 192#define type_cas_unlock()
 193
 194#endif
 195
 196
 197static int mark_link(struct object *obj, int type, void *data, struct fsck_options *options)
 198{
 199        if (!obj)
 200                return -1;
 201
 202        if (type != OBJ_ANY && obj->type != type)
 203                die(_("object type mismatch at %s"), oid_to_hex(&obj->oid));
 204
 205        obj->flags |= FLAG_LINK;
 206        return 0;
 207}
 208
 209/* The content of each linked object must have been checked
 210   or it must be already present in the object database */
 211static unsigned check_object(struct object *obj)
 212{
 213        if (!obj)
 214                return 0;
 215
 216        if (!(obj->flags & FLAG_LINK))
 217                return 0;
 218
 219        if (!(obj->flags & FLAG_CHECKED)) {
 220                unsigned long size;
 221                int type = sha1_object_info(obj->oid.hash, &size);
 222                if (type <= 0)
 223                        die(_("did not receive expected object %s"),
 224                              oid_to_hex(&obj->oid));
 225                if (type != obj->type)
 226                        die(_("object %s: expected type %s, found %s"),
 227                            oid_to_hex(&obj->oid),
 228                            typename(obj->type), typename(type));
 229                obj->flags |= FLAG_CHECKED;
 230                return 1;
 231        }
 232
 233        return 0;
 234}
 235
 236static unsigned check_objects(void)
 237{
 238        unsigned i, max, foreign_nr = 0;
 239
 240        max = get_max_object_index();
 241        for (i = 0; i < max; i++)
 242                foreign_nr += check_object(get_indexed_object(i));
 243        return foreign_nr;
 244}
 245
 246
 247/* Discard current buffer used content. */
 248static void flush(void)
 249{
 250        if (input_offset) {
 251                if (output_fd >= 0)
 252                        write_or_die(output_fd, input_buffer, input_offset);
 253                git_SHA1_Update(&input_ctx, input_buffer, input_offset);
 254                memmove(input_buffer, input_buffer + input_offset, input_len);
 255                input_offset = 0;
 256        }
 257}
 258
 259/*
 260 * Make sure at least "min" bytes are available in the buffer, and
 261 * return the pointer to the buffer.
 262 */
 263static void *fill(int min)
 264{
 265        if (min <= input_len)
 266                return input_buffer + input_offset;
 267        if (min > sizeof(input_buffer))
 268                die(Q_("cannot fill %d byte",
 269                       "cannot fill %d bytes",
 270                       min),
 271                    min);
 272        flush();
 273        do {
 274                ssize_t ret = xread(input_fd, input_buffer + input_len,
 275                                sizeof(input_buffer) - input_len);
 276                if (ret <= 0) {
 277                        if (!ret)
 278                                die(_("early EOF"));
 279                        die_errno(_("read error on input"));
 280                }
 281                input_len += ret;
 282                if (from_stdin)
 283                        display_throughput(progress, consumed_bytes + input_len);
 284        } while (input_len < min);
 285        return input_buffer;
 286}
 287
 288static void use(int bytes)
 289{
 290        if (bytes > input_len)
 291                die(_("used more bytes than were available"));
 292        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 293        input_len -= bytes;
 294        input_offset += bytes;
 295
 296        /* make sure off_t is sufficiently large not to wrap */
 297        if (signed_add_overflows(consumed_bytes, bytes))
 298                die(_("pack too large for current definition of off_t"));
 299        consumed_bytes += bytes;
 300}
 301
 302static const char *open_pack_file(const char *pack_name)
 303{
 304        if (from_stdin) {
 305                input_fd = 0;
 306                if (!pack_name) {
 307                        static char tmp_file[PATH_MAX];
 308                        output_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
 309                                                "pack/tmp_pack_XXXXXX");
 310                        pack_name = xstrdup(tmp_file);
 311                } else
 312                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 313                if (output_fd < 0)
 314                        die_errno(_("unable to create '%s'"), pack_name);
 315                nothread_data.pack_fd = output_fd;
 316        } else {
 317                input_fd = open(pack_name, O_RDONLY);
 318                if (input_fd < 0)
 319                        die_errno(_("cannot open packfile '%s'"), pack_name);
 320                output_fd = -1;
 321                nothread_data.pack_fd = input_fd;
 322        }
 323        git_SHA1_Init(&input_ctx);
 324        return pack_name;
 325}
 326
 327static void parse_pack_header(void)
 328{
 329        struct pack_header *hdr = fill(sizeof(struct pack_header));
 330
 331        /* Header consistency check */
 332        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 333                die(_("pack signature mismatch"));
 334        if (!pack_version_ok(hdr->hdr_version))
 335                die(_("pack version %"PRIu32" unsupported"),
 336                        ntohl(hdr->hdr_version));
 337
 338        nr_objects = ntohl(hdr->hdr_entries);
 339        use(sizeof(struct pack_header));
 340}
 341
 342static NORETURN void bad_object(off_t offset, const char *format,
 343                       ...) __attribute__((format (printf, 2, 3)));
 344
 345static NORETURN void bad_object(off_t offset, const char *format, ...)
 346{
 347        va_list params;
 348        char buf[1024];
 349
 350        va_start(params, format);
 351        vsnprintf(buf, sizeof(buf), format, params);
 352        va_end(params);
 353        die(_("pack has bad object at offset %"PRIuMAX": %s"),
 354            (uintmax_t)offset, buf);
 355}
 356
 357static inline struct thread_local *get_thread_data(void)
 358{
 359#ifndef NO_PTHREADS
 360        if (threads_active)
 361                return pthread_getspecific(key);
 362        assert(!threads_active &&
 363               "This should only be reached when all threads are gone");
 364#endif
 365        return &nothread_data;
 366}
 367
 368#ifndef NO_PTHREADS
 369static void set_thread_data(struct thread_local *data)
 370{
 371        if (threads_active)
 372                pthread_setspecific(key, data);
 373}
 374#endif
 375
 376static struct base_data *alloc_base_data(void)
 377{
 378        struct base_data *base = xcalloc(1, sizeof(struct base_data));
 379        base->ref_last = -1;
 380        base->ofs_last = -1;
 381        return base;
 382}
 383
 384static void free_base_data(struct base_data *c)
 385{
 386        if (c->data) {
 387                free(c->data);
 388                c->data = NULL;
 389                get_thread_data()->base_cache_used -= c->size;
 390        }
 391}
 392
 393static void prune_base_data(struct base_data *retain)
 394{
 395        struct base_data *b;
 396        struct thread_local *data = get_thread_data();
 397        for (b = data->base_cache;
 398             data->base_cache_used > delta_base_cache_limit && b;
 399             b = b->child) {
 400                if (b->data && b != retain)
 401                        free_base_data(b);
 402        }
 403}
 404
 405static void link_base_data(struct base_data *base, struct base_data *c)
 406{
 407        if (base)
 408                base->child = c;
 409        else
 410                get_thread_data()->base_cache = c;
 411
 412        c->base = base;
 413        c->child = NULL;
 414        if (c->data)
 415                get_thread_data()->base_cache_used += c->size;
 416        prune_base_data(c);
 417}
 418
 419static void unlink_base_data(struct base_data *c)
 420{
 421        struct base_data *base = c->base;
 422        if (base)
 423                base->child = NULL;
 424        else
 425                get_thread_data()->base_cache = NULL;
 426        free_base_data(c);
 427}
 428
 429static int is_delta_type(enum object_type type)
 430{
 431        return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 432}
 433
 434static void *unpack_entry_data(off_t offset, unsigned long size,
 435                               enum object_type type, unsigned char *sha1)
 436{
 437        static char fixed_buf[8192];
 438        int status;
 439        git_zstream stream;
 440        void *buf;
 441        git_SHA_CTX c;
 442        char hdr[32];
 443        int hdrlen;
 444
 445        if (!is_delta_type(type)) {
 446                hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), size) + 1;
 447                git_SHA1_Init(&c);
 448                git_SHA1_Update(&c, hdr, hdrlen);
 449        } else
 450                sha1 = NULL;
 451        if (type == OBJ_BLOB && size > big_file_threshold)
 452                buf = fixed_buf;
 453        else
 454                buf = xmallocz(size);
 455
 456        memset(&stream, 0, sizeof(stream));
 457        git_inflate_init(&stream);
 458        stream.next_out = buf;
 459        stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 460
 461        do {
 462                unsigned char *last_out = stream.next_out;
 463                stream.next_in = fill(1);
 464                stream.avail_in = input_len;
 465                status = git_inflate(&stream, 0);
 466                use(input_len - stream.avail_in);
 467                if (sha1)
 468                        git_SHA1_Update(&c, last_out, stream.next_out - last_out);
 469                if (buf == fixed_buf) {
 470                        stream.next_out = buf;
 471                        stream.avail_out = sizeof(fixed_buf);
 472                }
 473        } while (status == Z_OK);
 474        if (stream.total_out != size || status != Z_STREAM_END)
 475                bad_object(offset, _("inflate returned %d"), status);
 476        git_inflate_end(&stream);
 477        if (sha1)
 478                git_SHA1_Final(sha1, &c);
 479        return buf == fixed_buf ? NULL : buf;
 480}
 481
 482static void *unpack_raw_entry(struct object_entry *obj,
 483                              off_t *ofs_offset,
 484                              unsigned char *ref_sha1,
 485                              unsigned char *sha1)
 486{
 487        unsigned char *p;
 488        unsigned long size, c;
 489        off_t base_offset;
 490        unsigned shift;
 491        void *data;
 492
 493        obj->idx.offset = consumed_bytes;
 494        input_crc32 = crc32(0, NULL, 0);
 495
 496        p = fill(1);
 497        c = *p;
 498        use(1);
 499        obj->type = (c >> 4) & 7;
 500        size = (c & 15);
 501        shift = 4;
 502        while (c & 0x80) {
 503                p = fill(1);
 504                c = *p;
 505                use(1);
 506                size += (c & 0x7f) << shift;
 507                shift += 7;
 508        }
 509        obj->size = size;
 510
 511        switch (obj->type) {
 512        case OBJ_REF_DELTA:
 513                hashcpy(ref_sha1, fill(20));
 514                use(20);
 515                break;
 516        case OBJ_OFS_DELTA:
 517                p = fill(1);
 518                c = *p;
 519                use(1);
 520                base_offset = c & 127;
 521                while (c & 128) {
 522                        base_offset += 1;
 523                        if (!base_offset || MSB(base_offset, 7))
 524                                bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 525                        p = fill(1);
 526                        c = *p;
 527                        use(1);
 528                        base_offset = (base_offset << 7) + (c & 127);
 529                }
 530                *ofs_offset = obj->idx.offset - base_offset;
 531                if (*ofs_offset <= 0 || *ofs_offset >= obj->idx.offset)
 532                        bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 533                break;
 534        case OBJ_COMMIT:
 535        case OBJ_TREE:
 536        case OBJ_BLOB:
 537        case OBJ_TAG:
 538                break;
 539        default:
 540                bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 541        }
 542        obj->hdr_size = consumed_bytes - obj->idx.offset;
 543
 544        data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, sha1);
 545        obj->idx.crc32 = input_crc32;
 546        return data;
 547}
 548
 549static void *unpack_data(struct object_entry *obj,
 550                         int (*consume)(const unsigned char *, unsigned long, void *),
 551                         void *cb_data)
 552{
 553        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 554        off_t len = obj[1].idx.offset - from;
 555        unsigned char *data, *inbuf;
 556        git_zstream stream;
 557        int status;
 558
 559        data = xmallocz(consume ? 64*1024 : obj->size);
 560        inbuf = xmalloc((len < 64*1024) ? (int)len : 64*1024);
 561
 562        memset(&stream, 0, sizeof(stream));
 563        git_inflate_init(&stream);
 564        stream.next_out = data;
 565        stream.avail_out = consume ? 64*1024 : obj->size;
 566
 567        do {
 568                ssize_t n = (len < 64*1024) ? (ssize_t)len : 64*1024;
 569                n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 570                if (n < 0)
 571                        die_errno(_("cannot pread pack file"));
 572                if (!n)
 573                        die(Q_("premature end of pack file, %"PRIuMAX" byte missing",
 574                               "premature end of pack file, %"PRIuMAX" bytes missing",
 575                               (unsigned int)len),
 576                            (uintmax_t)len);
 577                from += n;
 578                len -= n;
 579                stream.next_in = inbuf;
 580                stream.avail_in = n;
 581                if (!consume)
 582                        status = git_inflate(&stream, 0);
 583                else {
 584                        do {
 585                                status = git_inflate(&stream, 0);
 586                                if (consume(data, stream.next_out - data, cb_data)) {
 587                                        free(inbuf);
 588                                        free(data);
 589                                        return NULL;
 590                                }
 591                                stream.next_out = data;
 592                                stream.avail_out = 64*1024;
 593                        } while (status == Z_OK && stream.avail_in);
 594                }
 595        } while (len && status == Z_OK && !stream.avail_in);
 596
 597        /* This has been inflated OK when first encountered, so... */
 598        if (status != Z_STREAM_END || stream.total_out != obj->size)
 599                die(_("serious inflate inconsistency"));
 600
 601        git_inflate_end(&stream);
 602        free(inbuf);
 603        if (consume) {
 604                free(data);
 605                data = NULL;
 606        }
 607        return data;
 608}
 609
 610static void *get_data_from_pack(struct object_entry *obj)
 611{
 612        return unpack_data(obj, NULL, NULL);
 613}
 614
 615static int compare_ofs_delta_bases(off_t offset1, off_t offset2,
 616                                   enum object_type type1,
 617                                   enum object_type type2)
 618{
 619        int cmp = type1 - type2;
 620        if (cmp)
 621                return cmp;
 622        return offset1 < offset2 ? -1 :
 623               offset1 > offset2 ?  1 :
 624               0;
 625}
 626
 627static int find_ofs_delta(const off_t offset, enum object_type type)
 628{
 629        int first = 0, last = nr_ofs_deltas;
 630
 631        while (first < last) {
 632                int next = (first + last) / 2;
 633                struct ofs_delta_entry *delta = &ofs_deltas[next];
 634                int cmp;
 635
 636                cmp = compare_ofs_delta_bases(offset, delta->offset,
 637                                              type, objects[delta->obj_no].type);
 638                if (!cmp)
 639                        return next;
 640                if (cmp < 0) {
 641                        last = next;
 642                        continue;
 643                }
 644                first = next+1;
 645        }
 646        return -first-1;
 647}
 648
 649static void find_ofs_delta_children(off_t offset,
 650                                    int *first_index, int *last_index,
 651                                    enum object_type type)
 652{
 653        int first = find_ofs_delta(offset, type);
 654        int last = first;
 655        int end = nr_ofs_deltas - 1;
 656
 657        if (first < 0) {
 658                *first_index = 0;
 659                *last_index = -1;
 660                return;
 661        }
 662        while (first > 0 && ofs_deltas[first - 1].offset == offset)
 663                --first;
 664        while (last < end && ofs_deltas[last + 1].offset == offset)
 665                ++last;
 666        *first_index = first;
 667        *last_index = last;
 668}
 669
 670static int compare_ref_delta_bases(const unsigned char *sha1,
 671                                   const unsigned char *sha2,
 672                                   enum object_type type1,
 673                                   enum object_type type2)
 674{
 675        int cmp = type1 - type2;
 676        if (cmp)
 677                return cmp;
 678        return hashcmp(sha1, sha2);
 679}
 680
 681static int find_ref_delta(const unsigned char *sha1, enum object_type type)
 682{
 683        int first = 0, last = nr_ref_deltas;
 684
 685        while (first < last) {
 686                int next = (first + last) / 2;
 687                struct ref_delta_entry *delta = &ref_deltas[next];
 688                int cmp;
 689
 690                cmp = compare_ref_delta_bases(sha1, delta->sha1,
 691                                              type, objects[delta->obj_no].type);
 692                if (!cmp)
 693                        return next;
 694                if (cmp < 0) {
 695                        last = next;
 696                        continue;
 697                }
 698                first = next+1;
 699        }
 700        return -first-1;
 701}
 702
 703static void find_ref_delta_children(const unsigned char *sha1,
 704                                    int *first_index, int *last_index,
 705                                    enum object_type type)
 706{
 707        int first = find_ref_delta(sha1, type);
 708        int last = first;
 709        int end = nr_ref_deltas - 1;
 710
 711        if (first < 0) {
 712                *first_index = 0;
 713                *last_index = -1;
 714                return;
 715        }
 716        while (first > 0 && !hashcmp(ref_deltas[first - 1].sha1, sha1))
 717                --first;
 718        while (last < end && !hashcmp(ref_deltas[last + 1].sha1, sha1))
 719                ++last;
 720        *first_index = first;
 721        *last_index = last;
 722}
 723
 724struct compare_data {
 725        struct object_entry *entry;
 726        struct git_istream *st;
 727        unsigned char *buf;
 728        unsigned long buf_size;
 729};
 730
 731static int compare_objects(const unsigned char *buf, unsigned long size,
 732                           void *cb_data)
 733{
 734        struct compare_data *data = cb_data;
 735
 736        if (data->buf_size < size) {
 737                free(data->buf);
 738                data->buf = xmalloc(size);
 739                data->buf_size = size;
 740        }
 741
 742        while (size) {
 743                ssize_t len = read_istream(data->st, data->buf, size);
 744                if (len == 0)
 745                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 746                            sha1_to_hex(data->entry->idx.sha1));
 747                if (len < 0)
 748                        die(_("unable to read %s"),
 749                            sha1_to_hex(data->entry->idx.sha1));
 750                if (memcmp(buf, data->buf, len))
 751                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 752                            sha1_to_hex(data->entry->idx.sha1));
 753                size -= len;
 754                buf += len;
 755        }
 756        return 0;
 757}
 758
 759static int check_collison(struct object_entry *entry)
 760{
 761        struct compare_data data;
 762        enum object_type type;
 763        unsigned long size;
 764
 765        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 766                return -1;
 767
 768        memset(&data, 0, sizeof(data));
 769        data.entry = entry;
 770        data.st = open_istream(entry->idx.sha1, &type, &size, NULL);
 771        if (!data.st)
 772                return -1;
 773        if (size != entry->size || type != entry->type)
 774                die(_("SHA1 COLLISION FOUND WITH %s !"),
 775                    sha1_to_hex(entry->idx.sha1));
 776        unpack_data(entry, compare_objects, &data);
 777        close_istream(data.st);
 778        free(data.buf);
 779        return 0;
 780}
 781
 782static void sha1_object(const void *data, struct object_entry *obj_entry,
 783                        unsigned long size, enum object_type type,
 784                        const unsigned char *sha1)
 785{
 786        void *new_data = NULL;
 787        int collision_test_needed;
 788
 789        assert(data || obj_entry);
 790
 791        read_lock();
 792        collision_test_needed = has_sha1_file_with_flags(sha1, HAS_SHA1_QUICK);
 793        read_unlock();
 794
 795        if (collision_test_needed && !data) {
 796                read_lock();
 797                if (!check_collison(obj_entry))
 798                        collision_test_needed = 0;
 799                read_unlock();
 800        }
 801        if (collision_test_needed) {
 802                void *has_data;
 803                enum object_type has_type;
 804                unsigned long has_size;
 805                read_lock();
 806                has_type = sha1_object_info(sha1, &has_size);
 807                if (has_type != type || has_size != size)
 808                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 809                has_data = read_sha1_file(sha1, &has_type, &has_size);
 810                read_unlock();
 811                if (!data)
 812                        data = new_data = get_data_from_pack(obj_entry);
 813                if (!has_data)
 814                        die(_("cannot read existing object %s"), sha1_to_hex(sha1));
 815                if (size != has_size || type != has_type ||
 816                    memcmp(data, has_data, size) != 0)
 817                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 818                free(has_data);
 819        }
 820
 821        if (strict) {
 822                read_lock();
 823                if (type == OBJ_BLOB) {
 824                        struct blob *blob = lookup_blob(sha1);
 825                        if (blob)
 826                                blob->object.flags |= FLAG_CHECKED;
 827                        else
 828                                die(_("invalid blob object %s"), sha1_to_hex(sha1));
 829                } else {
 830                        struct object *obj;
 831                        int eaten;
 832                        void *buf = (void *) data;
 833
 834                        assert(data && "data can only be NULL for large _blobs_");
 835
 836                        /*
 837                         * we do not need to free the memory here, as the
 838                         * buf is deleted by the caller.
 839                         */
 840                        obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 841                        if (!obj)
 842                                die(_("invalid %s"), typename(type));
 843                        if (do_fsck_object &&
 844                            fsck_object(obj, buf, size, &fsck_options))
 845                                die(_("Error in object"));
 846                        if (fsck_walk(obj, NULL, &fsck_options))
 847                                die(_("Not all child objects of %s are reachable"), oid_to_hex(&obj->oid));
 848
 849                        if (obj->type == OBJ_TREE) {
 850                                struct tree *item = (struct tree *) obj;
 851                                item->buffer = NULL;
 852                                obj->parsed = 0;
 853                        }
 854                        if (obj->type == OBJ_COMMIT) {
 855                                struct commit *commit = (struct commit *) obj;
 856                                if (detach_commit_buffer(commit, NULL) != data)
 857                                        die("BUG: parse_object_buffer transmogrified our buffer");
 858                        }
 859                        obj->flags |= FLAG_CHECKED;
 860                }
 861                read_unlock();
 862        }
 863
 864        free(new_data);
 865}
 866
 867/*
 868 * This function is part of find_unresolved_deltas(). There are two
 869 * walkers going in the opposite ways.
 870 *
 871 * The first one in find_unresolved_deltas() traverses down from
 872 * parent node to children, deflating nodes along the way. However,
 873 * memory for deflated nodes is limited by delta_base_cache_limit, so
 874 * at some point parent node's deflated content may be freed.
 875 *
 876 * The second walker is this function, which goes from current node up
 877 * to top parent if necessary to deflate the node. In normal
 878 * situation, its parent node would be already deflated, so it just
 879 * needs to apply delta.
 880 *
 881 * In the worst case scenario, parent node is no longer deflated because
 882 * we're running out of delta_base_cache_limit; we need to re-deflate
 883 * parents, possibly up to the top base.
 884 *
 885 * All deflated objects here are subject to be freed if we exceed
 886 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 887 * just need to make sure the last node is not freed.
 888 */
 889static void *get_base_data(struct base_data *c)
 890{
 891        if (!c->data) {
 892                struct object_entry *obj = c->obj;
 893                struct base_data **delta = NULL;
 894                int delta_nr = 0, delta_alloc = 0;
 895
 896                while (is_delta_type(c->obj->type) && !c->data) {
 897                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 898                        delta[delta_nr++] = c;
 899                        c = c->base;
 900                }
 901                if (!delta_nr) {
 902                        c->data = get_data_from_pack(obj);
 903                        c->size = obj->size;
 904                        get_thread_data()->base_cache_used += c->size;
 905                        prune_base_data(c);
 906                }
 907                for (; delta_nr > 0; delta_nr--) {
 908                        void *base, *raw;
 909                        c = delta[delta_nr - 1];
 910                        obj = c->obj;
 911                        base = get_base_data(c->base);
 912                        raw = get_data_from_pack(obj);
 913                        c->data = patch_delta(
 914                                base, c->base->size,
 915                                raw, obj->size,
 916                                &c->size);
 917                        free(raw);
 918                        if (!c->data)
 919                                bad_object(obj->idx.offset, _("failed to apply delta"));
 920                        get_thread_data()->base_cache_used += c->size;
 921                        prune_base_data(c);
 922                }
 923                free(delta);
 924        }
 925        return c->data;
 926}
 927
 928static void resolve_delta(struct object_entry *delta_obj,
 929                          struct base_data *base, struct base_data *result)
 930{
 931        void *base_data, *delta_data;
 932
 933        if (show_stat) {
 934                int i = delta_obj - objects;
 935                int j = base->obj - objects;
 936                obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 937                deepest_delta_lock();
 938                if (deepest_delta < obj_stat[i].delta_depth)
 939                        deepest_delta = obj_stat[i].delta_depth;
 940                deepest_delta_unlock();
 941                obj_stat[i].base_object_no = j;
 942        }
 943        delta_data = get_data_from_pack(delta_obj);
 944        base_data = get_base_data(base);
 945        result->obj = delta_obj;
 946        result->data = patch_delta(base_data, base->size,
 947                                   delta_data, delta_obj->size, &result->size);
 948        free(delta_data);
 949        if (!result->data)
 950                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 951        hash_sha1_file(result->data, result->size,
 952                       typename(delta_obj->real_type), delta_obj->idx.sha1);
 953        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 954                    delta_obj->idx.sha1);
 955        counter_lock();
 956        nr_resolved_deltas++;
 957        counter_unlock();
 958}
 959
 960/*
 961 * Standard boolean compare-and-swap: atomically check whether "*type" is
 962 * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 963 * and return false.
 964 */
 965static int compare_and_swap_type(signed char *type,
 966                                 enum object_type want,
 967                                 enum object_type set)
 968{
 969        enum object_type old;
 970
 971        type_cas_lock();
 972        old = *type;
 973        if (old == want)
 974                *type = set;
 975        type_cas_unlock();
 976
 977        return old == want;
 978}
 979
 980static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 981                                                  struct base_data *prev_base)
 982{
 983        if (base->ref_last == -1 && base->ofs_last == -1) {
 984                find_ref_delta_children(base->obj->idx.sha1,
 985                                        &base->ref_first, &base->ref_last,
 986                                        OBJ_REF_DELTA);
 987
 988                find_ofs_delta_children(base->obj->idx.offset,
 989                                        &base->ofs_first, &base->ofs_last,
 990                                        OBJ_OFS_DELTA);
 991
 992                if (base->ref_last == -1 && base->ofs_last == -1) {
 993                        free(base->data);
 994                        return NULL;
 995                }
 996
 997                link_base_data(prev_base, base);
 998        }
 999
1000        if (base->ref_first <= base->ref_last) {
1001                struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
1002                struct base_data *result = alloc_base_data();
1003
1004                if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
1005                                           base->obj->real_type))
1006                        die("BUG: child->real_type != OBJ_REF_DELTA");
1007
1008                resolve_delta(child, base, result);
1009                if (base->ref_first == base->ref_last && base->ofs_last == -1)
1010                        free_base_data(base);
1011
1012                base->ref_first++;
1013                return result;
1014        }
1015
1016        if (base->ofs_first <= base->ofs_last) {
1017                struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
1018                struct base_data *result = alloc_base_data();
1019
1020                assert(child->real_type == OBJ_OFS_DELTA);
1021                child->real_type = base->obj->real_type;
1022                resolve_delta(child, base, result);
1023                if (base->ofs_first == base->ofs_last)
1024                        free_base_data(base);
1025
1026                base->ofs_first++;
1027                return result;
1028        }
1029
1030        unlink_base_data(base);
1031        return NULL;
1032}
1033
1034static void find_unresolved_deltas(struct base_data *base)
1035{
1036        struct base_data *new_base, *prev_base = NULL;
1037        for (;;) {
1038                new_base = find_unresolved_deltas_1(base, prev_base);
1039
1040                if (new_base) {
1041                        prev_base = base;
1042                        base = new_base;
1043                } else {
1044                        free(base);
1045                        base = prev_base;
1046                        if (!base)
1047                                return;
1048                        prev_base = base->base;
1049                }
1050        }
1051}
1052
1053static int compare_ofs_delta_entry(const void *a, const void *b)
1054{
1055        const struct ofs_delta_entry *delta_a = a;
1056        const struct ofs_delta_entry *delta_b = b;
1057
1058        return delta_a->offset < delta_b->offset ? -1 :
1059               delta_a->offset > delta_b->offset ?  1 :
1060               0;
1061}
1062
1063static int compare_ref_delta_entry(const void *a, const void *b)
1064{
1065        const struct ref_delta_entry *delta_a = a;
1066        const struct ref_delta_entry *delta_b = b;
1067
1068        return hashcmp(delta_a->sha1, delta_b->sha1);
1069}
1070
1071static void resolve_base(struct object_entry *obj)
1072{
1073        struct base_data *base_obj = alloc_base_data();
1074        base_obj->obj = obj;
1075        base_obj->data = NULL;
1076        find_unresolved_deltas(base_obj);
1077}
1078
1079#ifndef NO_PTHREADS
1080static void *threaded_second_pass(void *data)
1081{
1082        set_thread_data(data);
1083        for (;;) {
1084                int i;
1085                counter_lock();
1086                display_progress(progress, nr_resolved_deltas);
1087                counter_unlock();
1088                work_lock();
1089                while (nr_dispatched < nr_objects &&
1090                       is_delta_type(objects[nr_dispatched].type))
1091                        nr_dispatched++;
1092                if (nr_dispatched >= nr_objects) {
1093                        work_unlock();
1094                        break;
1095                }
1096                i = nr_dispatched++;
1097                work_unlock();
1098
1099                resolve_base(&objects[i]);
1100        }
1101        return NULL;
1102}
1103#endif
1104
1105/*
1106 * First pass:
1107 * - find locations of all objects;
1108 * - calculate SHA1 of all non-delta objects;
1109 * - remember base (SHA1 or offset) for all deltas.
1110 */
1111static void parse_pack_objects(unsigned char *sha1)
1112{
1113        int i, nr_delays = 0;
1114        struct ofs_delta_entry *ofs_delta = ofs_deltas;
1115        unsigned char ref_delta_sha1[20];
1116        struct stat st;
1117
1118        if (verbose)
1119                progress = start_progress(
1120                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1121                                nr_objects);
1122        for (i = 0; i < nr_objects; i++) {
1123                struct object_entry *obj = &objects[i];
1124                void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1125                                              ref_delta_sha1, obj->idx.sha1);
1126                obj->real_type = obj->type;
1127                if (obj->type == OBJ_OFS_DELTA) {
1128                        nr_ofs_deltas++;
1129                        ofs_delta->obj_no = i;
1130                        ofs_delta++;
1131                } else if (obj->type == OBJ_REF_DELTA) {
1132                        ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1133                        hashcpy(ref_deltas[nr_ref_deltas].sha1, ref_delta_sha1);
1134                        ref_deltas[nr_ref_deltas].obj_no = i;
1135                        nr_ref_deltas++;
1136                } else if (!data) {
1137                        /* large blobs, check later */
1138                        obj->real_type = OBJ_BAD;
1139                        nr_delays++;
1140                } else
1141                        sha1_object(data, NULL, obj->size, obj->type, obj->idx.sha1);
1142                free(data);
1143                display_progress(progress, i+1);
1144        }
1145        objects[i].idx.offset = consumed_bytes;
1146        stop_progress(&progress);
1147
1148        /* Check pack integrity */
1149        flush();
1150        git_SHA1_Final(sha1, &input_ctx);
1151        if (hashcmp(fill(20), sha1))
1152                die(_("pack is corrupted (SHA1 mismatch)"));
1153        use(20);
1154
1155        /* If input_fd is a file, we should have reached its end now. */
1156        if (fstat(input_fd, &st))
1157                die_errno(_("cannot fstat packfile"));
1158        if (S_ISREG(st.st_mode) &&
1159                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1160                die(_("pack has junk at the end"));
1161
1162        for (i = 0; i < nr_objects; i++) {
1163                struct object_entry *obj = &objects[i];
1164                if (obj->real_type != OBJ_BAD)
1165                        continue;
1166                obj->real_type = obj->type;
1167                sha1_object(NULL, obj, obj->size, obj->type, obj->idx.sha1);
1168                nr_delays--;
1169        }
1170        if (nr_delays)
1171                die(_("confusion beyond insanity in parse_pack_objects()"));
1172}
1173
1174/*
1175 * Second pass:
1176 * - for all non-delta objects, look if it is used as a base for
1177 *   deltas;
1178 * - if used as a base, uncompress the object and apply all deltas,
1179 *   recursively checking if the resulting object is used as a base
1180 *   for some more deltas.
1181 */
1182static void resolve_deltas(void)
1183{
1184        int i;
1185
1186        if (!nr_ofs_deltas && !nr_ref_deltas)
1187                return;
1188
1189        /* Sort deltas by base SHA1/offset for fast searching */
1190        qsort(ofs_deltas, nr_ofs_deltas, sizeof(struct ofs_delta_entry),
1191              compare_ofs_delta_entry);
1192        qsort(ref_deltas, nr_ref_deltas, sizeof(struct ref_delta_entry),
1193              compare_ref_delta_entry);
1194
1195        if (verbose || show_resolving_progress)
1196                progress = start_progress(_("Resolving deltas"),
1197                                          nr_ref_deltas + nr_ofs_deltas);
1198
1199#ifndef NO_PTHREADS
1200        nr_dispatched = 0;
1201        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1202                init_thread();
1203                for (i = 0; i < nr_threads; i++) {
1204                        int ret = pthread_create(&thread_data[i].thread, NULL,
1205                                                 threaded_second_pass, thread_data + i);
1206                        if (ret)
1207                                die(_("unable to create thread: %s"),
1208                                    strerror(ret));
1209                }
1210                for (i = 0; i < nr_threads; i++)
1211                        pthread_join(thread_data[i].thread, NULL);
1212                cleanup_thread();
1213                return;
1214        }
1215#endif
1216
1217        for (i = 0; i < nr_objects; i++) {
1218                struct object_entry *obj = &objects[i];
1219
1220                if (is_delta_type(obj->type))
1221                        continue;
1222                resolve_base(obj);
1223                display_progress(progress, nr_resolved_deltas);
1224        }
1225}
1226
1227/*
1228 * Third pass:
1229 * - append objects to convert thin pack to full pack if required
1230 * - write the final 20-byte SHA-1
1231 */
1232static void fix_unresolved_deltas(struct sha1file *f);
1233static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
1234{
1235        if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1236                stop_progress(&progress);
1237                /* Flush remaining pack final 20-byte SHA1. */
1238                flush();
1239                return;
1240        }
1241
1242        if (fix_thin_pack) {
1243                struct sha1file *f;
1244                unsigned char read_sha1[20], tail_sha1[20];
1245                struct strbuf msg = STRBUF_INIT;
1246                int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1247                int nr_objects_initial = nr_objects;
1248                if (nr_unresolved <= 0)
1249                        die(_("confusion beyond insanity"));
1250                REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1251                memset(objects + nr_objects + 1, 0,
1252                       nr_unresolved * sizeof(*objects));
1253                f = sha1fd(output_fd, curr_pack);
1254                fix_unresolved_deltas(f);
1255                strbuf_addf(&msg, Q_("completed with %d local object",
1256                                     "completed with %d local objects",
1257                                     nr_objects - nr_objects_initial),
1258                            nr_objects - nr_objects_initial);
1259                stop_progress_msg(&progress, msg.buf);
1260                strbuf_release(&msg);
1261                sha1close(f, tail_sha1, 0);
1262                hashcpy(read_sha1, pack_sha1);
1263                fixup_pack_header_footer(output_fd, pack_sha1,
1264                                         curr_pack, nr_objects,
1265                                         read_sha1, consumed_bytes-20);
1266                if (hashcmp(read_sha1, tail_sha1) != 0)
1267                        die(_("Unexpected tail checksum for %s "
1268                              "(disk corruption?)"), curr_pack);
1269        }
1270        if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1271                die(Q_("pack has %d unresolved delta",
1272                       "pack has %d unresolved deltas",
1273                       nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1274                    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1275}
1276
1277static int write_compressed(struct sha1file *f, void *in, unsigned int size)
1278{
1279        git_zstream stream;
1280        int status;
1281        unsigned char outbuf[4096];
1282
1283        git_deflate_init(&stream, zlib_compression_level);
1284        stream.next_in = in;
1285        stream.avail_in = size;
1286
1287        do {
1288                stream.next_out = outbuf;
1289                stream.avail_out = sizeof(outbuf);
1290                status = git_deflate(&stream, Z_FINISH);
1291                sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
1292        } while (status == Z_OK);
1293
1294        if (status != Z_STREAM_END)
1295                die(_("unable to deflate appended object (%d)"), status);
1296        size = stream.total_out;
1297        git_deflate_end(&stream);
1298        return size;
1299}
1300
1301static struct object_entry *append_obj_to_pack(struct sha1file *f,
1302                               const unsigned char *sha1, void *buf,
1303                               unsigned long size, enum object_type type)
1304{
1305        struct object_entry *obj = &objects[nr_objects++];
1306        unsigned char header[10];
1307        unsigned long s = size;
1308        int n = 0;
1309        unsigned char c = (type << 4) | (s & 15);
1310        s >>= 4;
1311        while (s) {
1312                header[n++] = c | 0x80;
1313                c = s & 0x7f;
1314                s >>= 7;
1315        }
1316        header[n++] = c;
1317        crc32_begin(f);
1318        sha1write(f, header, n);
1319        obj[0].size = size;
1320        obj[0].hdr_size = n;
1321        obj[0].type = type;
1322        obj[0].real_type = type;
1323        obj[1].idx.offset = obj[0].idx.offset + n;
1324        obj[1].idx.offset += write_compressed(f, buf, size);
1325        obj[0].idx.crc32 = crc32_end(f);
1326        sha1flush(f);
1327        hashcpy(obj->idx.sha1, sha1);
1328        return obj;
1329}
1330
1331static int delta_pos_compare(const void *_a, const void *_b)
1332{
1333        struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1334        struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1335        return a->obj_no - b->obj_no;
1336}
1337
1338static void fix_unresolved_deltas(struct sha1file *f)
1339{
1340        struct ref_delta_entry **sorted_by_pos;
1341        int i;
1342
1343        /*
1344         * Since many unresolved deltas may well be themselves base objects
1345         * for more unresolved deltas, we really want to include the
1346         * smallest number of base objects that would cover as much delta
1347         * as possible by picking the
1348         * trunc deltas first, allowing for other deltas to resolve without
1349         * additional base objects.  Since most base objects are to be found
1350         * before deltas depending on them, a good heuristic is to start
1351         * resolving deltas in the same order as their position in the pack.
1352         */
1353        ALLOC_ARRAY(sorted_by_pos, nr_ref_deltas);
1354        for (i = 0; i < nr_ref_deltas; i++)
1355                sorted_by_pos[i] = &ref_deltas[i];
1356        qsort(sorted_by_pos, nr_ref_deltas, sizeof(*sorted_by_pos), delta_pos_compare);
1357
1358        for (i = 0; i < nr_ref_deltas; i++) {
1359                struct ref_delta_entry *d = sorted_by_pos[i];
1360                enum object_type type;
1361                struct base_data *base_obj = alloc_base_data();
1362
1363                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1364                        continue;
1365                base_obj->data = read_sha1_file(d->sha1, &type, &base_obj->size);
1366                if (!base_obj->data)
1367                        continue;
1368
1369                if (check_sha1_signature(d->sha1, base_obj->data,
1370                                base_obj->size, typename(type)))
1371                        die(_("local object %s is corrupt"), sha1_to_hex(d->sha1));
1372                base_obj->obj = append_obj_to_pack(f, d->sha1,
1373                                        base_obj->data, base_obj->size, type);
1374                find_unresolved_deltas(base_obj);
1375                display_progress(progress, nr_resolved_deltas);
1376        }
1377        free(sorted_by_pos);
1378}
1379
1380static void final(const char *final_pack_name, const char *curr_pack_name,
1381                  const char *final_index_name, const char *curr_index_name,
1382                  const char *keep_name, const char *keep_msg,
1383                  unsigned char *sha1)
1384{
1385        const char *report = "pack";
1386        char name[PATH_MAX];
1387        int err;
1388
1389        if (!from_stdin) {
1390                close(input_fd);
1391        } else {
1392                fsync_or_die(output_fd, curr_pack_name);
1393                err = close(output_fd);
1394                if (err)
1395                        die_errno(_("error while closing pack file"));
1396        }
1397
1398        if (keep_msg) {
1399                int keep_fd, keep_msg_len = strlen(keep_msg);
1400
1401                if (!keep_name)
1402                        keep_fd = odb_pack_keep(name, sizeof(name), sha1);
1403                else
1404                        keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
1405
1406                if (keep_fd < 0) {
1407                        if (errno != EEXIST)
1408                                die_errno(_("cannot write keep file '%s'"),
1409                                          keep_name ? keep_name : name);
1410                } else {
1411                        if (keep_msg_len > 0) {
1412                                write_or_die(keep_fd, keep_msg, keep_msg_len);
1413                                write_or_die(keep_fd, "\n", 1);
1414                        }
1415                        if (close(keep_fd) != 0)
1416                                die_errno(_("cannot close written keep file '%s'"),
1417                                          keep_name ? keep_name : name);
1418                        report = "keep";
1419                }
1420        }
1421
1422        if (final_pack_name != curr_pack_name) {
1423                if (!final_pack_name) {
1424                        snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
1425                                 get_object_directory(), sha1_to_hex(sha1));
1426                        final_pack_name = name;
1427                }
1428                if (finalize_object_file(curr_pack_name, final_pack_name))
1429                        die(_("cannot store pack file"));
1430        } else if (from_stdin)
1431                chmod(final_pack_name, 0444);
1432
1433        if (final_index_name != curr_index_name) {
1434                if (!final_index_name) {
1435                        snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
1436                                 get_object_directory(), sha1_to_hex(sha1));
1437                        final_index_name = name;
1438                }
1439                if (finalize_object_file(curr_index_name, final_index_name))
1440                        die(_("cannot store index file"));
1441        } else
1442                chmod(final_index_name, 0444);
1443
1444        if (!from_stdin) {
1445                printf("%s\n", sha1_to_hex(sha1));
1446        } else {
1447                char buf[48];
1448                int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
1449                                   report, sha1_to_hex(sha1));
1450                write_or_die(1, buf, len);
1451
1452                /*
1453                 * Let's just mimic git-unpack-objects here and write
1454                 * the last part of the input buffer to stdout.
1455                 */
1456                while (input_len) {
1457                        err = xwrite(1, input_buffer + input_offset, input_len);
1458                        if (err <= 0)
1459                                break;
1460                        input_len -= err;
1461                        input_offset += err;
1462                }
1463        }
1464}
1465
1466static int git_index_pack_config(const char *k, const char *v, void *cb)
1467{
1468        struct pack_idx_option *opts = cb;
1469
1470        if (!strcmp(k, "pack.indexversion")) {
1471                opts->version = git_config_int(k, v);
1472                if (opts->version > 2)
1473                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1474                return 0;
1475        }
1476        if (!strcmp(k, "pack.threads")) {
1477                nr_threads = git_config_int(k, v);
1478                if (nr_threads < 0)
1479                        die(_("invalid number of threads specified (%d)"),
1480                            nr_threads);
1481#ifdef NO_PTHREADS
1482                if (nr_threads != 1)
1483                        warning(_("no threads support, ignoring %s"), k);
1484                nr_threads = 1;
1485#endif
1486                return 0;
1487        }
1488        return git_default_config(k, v, cb);
1489}
1490
1491static int cmp_uint32(const void *a_, const void *b_)
1492{
1493        uint32_t a = *((uint32_t *)a_);
1494        uint32_t b = *((uint32_t *)b_);
1495
1496        return (a < b) ? -1 : (a != b);
1497}
1498
1499static void read_v2_anomalous_offsets(struct packed_git *p,
1500                                      struct pack_idx_option *opts)
1501{
1502        const uint32_t *idx1, *idx2;
1503        uint32_t i;
1504
1505        /* The address of the 4-byte offset table */
1506        idx1 = (((const uint32_t *)p->index_data)
1507                + 2 /* 8-byte header */
1508                + 256 /* fan out */
1509                + 5 * p->num_objects /* 20-byte SHA-1 table */
1510                + p->num_objects /* CRC32 table */
1511                );
1512
1513        /* The address of the 8-byte offset table */
1514        idx2 = idx1 + p->num_objects;
1515
1516        for (i = 0; i < p->num_objects; i++) {
1517                uint32_t off = ntohl(idx1[i]);
1518                if (!(off & 0x80000000))
1519                        continue;
1520                off = off & 0x7fffffff;
1521                check_pack_index_ptr(p, &idx2[off * 2]);
1522                if (idx2[off * 2])
1523                        continue;
1524                /*
1525                 * The real offset is ntohl(idx2[off * 2]) in high 4
1526                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1527                 * octets.  But idx2[off * 2] is Zero!!!
1528                 */
1529                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1530                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1531        }
1532
1533        if (1 < opts->anomaly_nr)
1534                qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
1535}
1536
1537static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1538{
1539        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1540
1541        if (!p)
1542                die(_("Cannot open existing pack file '%s'"), pack_name);
1543        if (open_pack_index(p))
1544                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1545
1546        /* Read the attributes from the existing idx file */
1547        opts->version = p->index_version;
1548
1549        if (opts->version == 2)
1550                read_v2_anomalous_offsets(p, opts);
1551
1552        /*
1553         * Get rid of the idx file as we do not need it anymore.
1554         * NEEDSWORK: extract this bit from free_pack_by_name() in
1555         * sha1_file.c, perhaps?  It shouldn't matter very much as we
1556         * know we haven't installed this pack (hence we never have
1557         * read anything from it).
1558         */
1559        close_pack_index(p);
1560        free(p);
1561}
1562
1563static void show_pack_info(int stat_only)
1564{
1565        int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1566        unsigned long *chain_histogram = NULL;
1567
1568        if (deepest_delta)
1569                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1570
1571        for (i = 0; i < nr_objects; i++) {
1572                struct object_entry *obj = &objects[i];
1573
1574                if (is_delta_type(obj->type))
1575                        chain_histogram[obj_stat[i].delta_depth - 1]++;
1576                if (stat_only)
1577                        continue;
1578                printf("%s %-6s %lu %lu %"PRIuMAX,
1579                       sha1_to_hex(obj->idx.sha1),
1580                       typename(obj->real_type), obj->size,
1581                       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1582                       (uintmax_t)obj->idx.offset);
1583                if (is_delta_type(obj->type)) {
1584                        struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1585                        printf(" %u %s", obj_stat[i].delta_depth, sha1_to_hex(bobj->idx.sha1));
1586                }
1587                putchar('\n');
1588        }
1589
1590        if (baseobjects)
1591                printf_ln(Q_("non delta: %d object",
1592                             "non delta: %d objects",
1593                             baseobjects),
1594                          baseobjects);
1595        for (i = 0; i < deepest_delta; i++) {
1596                if (!chain_histogram[i])
1597                        continue;
1598                printf_ln(Q_("chain length = %d: %lu object",
1599                             "chain length = %d: %lu objects",
1600                             chain_histogram[i]),
1601                          i + 1,
1602                          chain_histogram[i]);
1603        }
1604}
1605
1606static const char *derive_filename(const char *pack_name, const char *suffix,
1607                                   struct strbuf *buf)
1608{
1609        size_t len;
1610        if (!strip_suffix(pack_name, ".pack", &len))
1611                die(_("packfile name '%s' does not end with '.pack'"),
1612                    pack_name);
1613        strbuf_add(buf, pack_name, len);
1614        strbuf_addstr(buf, suffix);
1615        return buf->buf;
1616}
1617
1618int cmd_index_pack(int argc, const char **argv, const char *prefix)
1619{
1620        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1621        const char *curr_index;
1622        const char *index_name = NULL, *pack_name = NULL;
1623        const char *keep_name = NULL, *keep_msg = NULL;
1624        struct strbuf index_name_buf = STRBUF_INIT,
1625                      keep_name_buf = STRBUF_INIT;
1626        struct pack_idx_entry **idx_objects;
1627        struct pack_idx_option opts;
1628        unsigned char pack_sha1[20];
1629        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1630        int report_end_of_input = 0;
1631
1632        if (argc == 2 && !strcmp(argv[1], "-h"))
1633                usage(index_pack_usage);
1634
1635        check_replace_refs = 0;
1636        fsck_options.walk = mark_link;
1637
1638        reset_pack_idx_option(&opts);
1639        git_config(git_index_pack_config, &opts);
1640        if (prefix && chdir(prefix))
1641                die(_("Cannot come back to cwd"));
1642
1643        for (i = 1; i < argc; i++) {
1644                const char *arg = argv[i];
1645
1646                if (*arg == '-') {
1647                        if (!strcmp(arg, "--stdin")) {
1648                                from_stdin = 1;
1649                        } else if (!strcmp(arg, "--fix-thin")) {
1650                                fix_thin_pack = 1;
1651                        } else if (!strcmp(arg, "--strict")) {
1652                                strict = 1;
1653                                do_fsck_object = 1;
1654                        } else if (skip_prefix(arg, "--strict=", &arg)) {
1655                                strict = 1;
1656                                do_fsck_object = 1;
1657                                fsck_set_msg_types(&fsck_options, arg);
1658                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1659                                strict = 1;
1660                                check_self_contained_and_connected = 1;
1661                        } else if (!strcmp(arg, "--verify")) {
1662                                verify = 1;
1663                        } else if (!strcmp(arg, "--verify-stat")) {
1664                                verify = 1;
1665                                show_stat = 1;
1666                        } else if (!strcmp(arg, "--verify-stat-only")) {
1667                                verify = 1;
1668                                show_stat = 1;
1669                                stat_only = 1;
1670                        } else if (!strcmp(arg, "--keep")) {
1671                                keep_msg = "";
1672                        } else if (starts_with(arg, "--keep=")) {
1673                                keep_msg = arg + 7;
1674                        } else if (starts_with(arg, "--threads=")) {
1675                                char *end;
1676                                nr_threads = strtoul(arg+10, &end, 0);
1677                                if (!arg[10] || *end || nr_threads < 0)
1678                                        usage(index_pack_usage);
1679#ifdef NO_PTHREADS
1680                                if (nr_threads != 1)
1681                                        warning(_("no threads support, "
1682                                                  "ignoring %s"), arg);
1683                                nr_threads = 1;
1684#endif
1685                        } else if (starts_with(arg, "--pack_header=")) {
1686                                struct pack_header *hdr;
1687                                char *c;
1688
1689                                hdr = (struct pack_header *)input_buffer;
1690                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1691                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1692                                if (*c != ',')
1693                                        die(_("bad %s"), arg);
1694                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1695                                if (*c)
1696                                        die(_("bad %s"), arg);
1697                                input_len = sizeof(*hdr);
1698                        } else if (!strcmp(arg, "-v")) {
1699                                verbose = 1;
1700                        } else if (!strcmp(arg, "--show-resolving-progress")) {
1701                                show_resolving_progress = 1;
1702                        } else if (!strcmp(arg, "--report-end-of-input")) {
1703                                report_end_of_input = 1;
1704                        } else if (!strcmp(arg, "-o")) {
1705                                if (index_name || (i+1) >= argc)
1706                                        usage(index_pack_usage);
1707                                index_name = argv[++i];
1708                        } else if (starts_with(arg, "--index-version=")) {
1709                                char *c;
1710                                opts.version = strtoul(arg + 16, &c, 10);
1711                                if (opts.version > 2)
1712                                        die(_("bad %s"), arg);
1713                                if (*c == ',')
1714                                        opts.off32_limit = strtoul(c+1, &c, 0);
1715                                if (*c || opts.off32_limit & 0x80000000)
1716                                        die(_("bad %s"), arg);
1717                        } else
1718                                usage(index_pack_usage);
1719                        continue;
1720                }
1721
1722                if (pack_name)
1723                        usage(index_pack_usage);
1724                pack_name = arg;
1725        }
1726
1727        if (!pack_name && !from_stdin)
1728                usage(index_pack_usage);
1729        if (fix_thin_pack && !from_stdin)
1730                die(_("--fix-thin cannot be used without --stdin"));
1731        if (!index_name && pack_name)
1732                index_name = derive_filename(pack_name, ".idx", &index_name_buf);
1733        if (keep_msg && !keep_name && pack_name)
1734                keep_name = derive_filename(pack_name, ".keep", &keep_name_buf);
1735
1736        if (verify) {
1737                if (!index_name)
1738                        die(_("--verify with no packfile name given"));
1739                read_idx_option(&opts, index_name);
1740                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1741        }
1742        if (strict)
1743                opts.flags |= WRITE_IDX_STRICT;
1744
1745#ifndef NO_PTHREADS
1746        if (!nr_threads) {
1747                nr_threads = online_cpus();
1748                /* An experiment showed that more threads does not mean faster */
1749                if (nr_threads > 3)
1750                        nr_threads = 3;
1751        }
1752#endif
1753
1754        curr_pack = open_pack_file(pack_name);
1755        parse_pack_header();
1756        objects = xcalloc(st_add(nr_objects, 1), sizeof(struct object_entry));
1757        if (show_stat)
1758                obj_stat = xcalloc(st_add(nr_objects, 1), sizeof(struct object_stat));
1759        ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
1760        parse_pack_objects(pack_sha1);
1761        if (report_end_of_input)
1762                write_in_full(2, "\0", 1);
1763        resolve_deltas();
1764        conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1765        free(ofs_deltas);
1766        free(ref_deltas);
1767        if (strict)
1768                foreign_nr = check_objects();
1769
1770        if (show_stat)
1771                show_pack_info(stat_only);
1772
1773        ALLOC_ARRAY(idx_objects, nr_objects);
1774        for (i = 0; i < nr_objects; i++)
1775                idx_objects[i] = &objects[i].idx;
1776        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1777        free(idx_objects);
1778
1779        if (!verify)
1780                final(pack_name, curr_pack,
1781                      index_name, curr_index,
1782                      keep_name, keep_msg,
1783                      pack_sha1);
1784        else
1785                close(input_fd);
1786        free(objects);
1787        strbuf_release(&index_name_buf);
1788        strbuf_release(&keep_name_buf);
1789        if (pack_name == NULL)
1790                free((void *) curr_pack);
1791        if (index_name == NULL)
1792                free((void *) curr_index);
1793
1794        /*
1795         * Let the caller know this pack is not self contained
1796         */
1797        if (check_self_contained_and_connected && foreign_nr)
1798                return 1;
1799
1800        return 0;
1801}