builtin / index-pack.con commit index-pack: detect local corruption in collision check (5105417)
   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 off_t max_input_size;
  91static unsigned deepest_delta;
  92static git_SHA_CTX input_ctx;
  93static uint32_t input_crc32;
  94static int input_fd, output_fd;
  95static const char *curr_pack;
  96
  97#ifndef NO_PTHREADS
  98
  99static struct thread_local *thread_data;
 100static int nr_dispatched;
 101static int threads_active;
 102
 103static pthread_mutex_t read_mutex;
 104#define read_lock()             lock_mutex(&read_mutex)
 105#define read_unlock()           unlock_mutex(&read_mutex)
 106
 107static pthread_mutex_t counter_mutex;
 108#define counter_lock()          lock_mutex(&counter_mutex)
 109#define counter_unlock()        unlock_mutex(&counter_mutex)
 110
 111static pthread_mutex_t work_mutex;
 112#define work_lock()             lock_mutex(&work_mutex)
 113#define work_unlock()           unlock_mutex(&work_mutex)
 114
 115static pthread_mutex_t deepest_delta_mutex;
 116#define deepest_delta_lock()    lock_mutex(&deepest_delta_mutex)
 117#define deepest_delta_unlock()  unlock_mutex(&deepest_delta_mutex)
 118
 119static pthread_mutex_t type_cas_mutex;
 120#define type_cas_lock()         lock_mutex(&type_cas_mutex)
 121#define type_cas_unlock()       unlock_mutex(&type_cas_mutex)
 122
 123static pthread_key_t key;
 124
 125static inline void lock_mutex(pthread_mutex_t *mutex)
 126{
 127        if (threads_active)
 128                pthread_mutex_lock(mutex);
 129}
 130
 131static inline void unlock_mutex(pthread_mutex_t *mutex)
 132{
 133        if (threads_active)
 134                pthread_mutex_unlock(mutex);
 135}
 136
 137/*
 138 * Mutex and conditional variable can't be statically-initialized on Windows.
 139 */
 140static void init_thread(void)
 141{
 142        int i;
 143        init_recursive_mutex(&read_mutex);
 144        pthread_mutex_init(&counter_mutex, NULL);
 145        pthread_mutex_init(&work_mutex, NULL);
 146        pthread_mutex_init(&type_cas_mutex, NULL);
 147        if (show_stat)
 148                pthread_mutex_init(&deepest_delta_mutex, NULL);
 149        pthread_key_create(&key, NULL);
 150        thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 151        for (i = 0; i < nr_threads; i++) {
 152                thread_data[i].pack_fd = open(curr_pack, O_RDONLY);
 153                if (thread_data[i].pack_fd == -1)
 154                        die_errno(_("unable to open %s"), curr_pack);
 155        }
 156
 157        threads_active = 1;
 158}
 159
 160static void cleanup_thread(void)
 161{
 162        int i;
 163        if (!threads_active)
 164                return;
 165        threads_active = 0;
 166        pthread_mutex_destroy(&read_mutex);
 167        pthread_mutex_destroy(&counter_mutex);
 168        pthread_mutex_destroy(&work_mutex);
 169        pthread_mutex_destroy(&type_cas_mutex);
 170        if (show_stat)
 171                pthread_mutex_destroy(&deepest_delta_mutex);
 172        for (i = 0; i < nr_threads; i++)
 173                close(thread_data[i].pack_fd);
 174        pthread_key_delete(key);
 175        free(thread_data);
 176}
 177
 178#else
 179
 180#define read_lock()
 181#define read_unlock()
 182
 183#define counter_lock()
 184#define counter_unlock()
 185
 186#define work_lock()
 187#define work_unlock()
 188
 189#define deepest_delta_lock()
 190#define deepest_delta_unlock()
 191
 192#define type_cas_lock()
 193#define type_cas_unlock()
 194
 195#endif
 196
 197
 198static int mark_link(struct object *obj, int type, void *data, struct fsck_options *options)
 199{
 200        if (!obj)
 201                return -1;
 202
 203        if (type != OBJ_ANY && obj->type != type)
 204                die(_("object type mismatch at %s"), oid_to_hex(&obj->oid));
 205
 206        obj->flags |= FLAG_LINK;
 207        return 0;
 208}
 209
 210/* The content of each linked object must have been checked
 211   or it must be already present in the object database */
 212static unsigned check_object(struct object *obj)
 213{
 214        if (!obj)
 215                return 0;
 216
 217        if (!(obj->flags & FLAG_LINK))
 218                return 0;
 219
 220        if (!(obj->flags & FLAG_CHECKED)) {
 221                unsigned long size;
 222                int type = sha1_object_info(obj->oid.hash, &size);
 223                if (type <= 0)
 224                        die(_("did not receive expected object %s"),
 225                              oid_to_hex(&obj->oid));
 226                if (type != obj->type)
 227                        die(_("object %s: expected type %s, found %s"),
 228                            oid_to_hex(&obj->oid),
 229                            typename(obj->type), typename(type));
 230                obj->flags |= FLAG_CHECKED;
 231                return 1;
 232        }
 233
 234        return 0;
 235}
 236
 237static unsigned check_objects(void)
 238{
 239        unsigned i, max, foreign_nr = 0;
 240
 241        max = get_max_object_index();
 242        for (i = 0; i < max; i++)
 243                foreign_nr += check_object(get_indexed_object(i));
 244        return foreign_nr;
 245}
 246
 247
 248/* Discard current buffer used content. */
 249static void flush(void)
 250{
 251        if (input_offset) {
 252                if (output_fd >= 0)
 253                        write_or_die(output_fd, input_buffer, input_offset);
 254                git_SHA1_Update(&input_ctx, input_buffer, input_offset);
 255                memmove(input_buffer, input_buffer + input_offset, input_len);
 256                input_offset = 0;
 257        }
 258}
 259
 260/*
 261 * Make sure at least "min" bytes are available in the buffer, and
 262 * return the pointer to the buffer.
 263 */
 264static void *fill(int min)
 265{
 266        if (min <= input_len)
 267                return input_buffer + input_offset;
 268        if (min > sizeof(input_buffer))
 269                die(Q_("cannot fill %d byte",
 270                       "cannot fill %d bytes",
 271                       min),
 272                    min);
 273        flush();
 274        do {
 275                ssize_t ret = xread(input_fd, input_buffer + input_len,
 276                                sizeof(input_buffer) - input_len);
 277                if (ret <= 0) {
 278                        if (!ret)
 279                                die(_("early EOF"));
 280                        die_errno(_("read error on input"));
 281                }
 282                input_len += ret;
 283                if (from_stdin)
 284                        display_throughput(progress, consumed_bytes + input_len);
 285        } while (input_len < min);
 286        return input_buffer;
 287}
 288
 289static void use(int bytes)
 290{
 291        if (bytes > input_len)
 292                die(_("used more bytes than were available"));
 293        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 294        input_len -= bytes;
 295        input_offset += bytes;
 296
 297        /* make sure off_t is sufficiently large not to wrap */
 298        if (signed_add_overflows(consumed_bytes, bytes))
 299                die(_("pack too large for current definition of off_t"));
 300        consumed_bytes += bytes;
 301        if (max_input_size && consumed_bytes > max_input_size)
 302                die(_("pack exceeds maximum allowed size"));
 303}
 304
 305static const char *open_pack_file(const char *pack_name)
 306{
 307        if (from_stdin) {
 308                input_fd = 0;
 309                if (!pack_name) {
 310                        static char tmp_file[PATH_MAX];
 311                        output_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
 312                                                "pack/tmp_pack_XXXXXX");
 313                        pack_name = xstrdup(tmp_file);
 314                } else
 315                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 316                if (output_fd < 0)
 317                        die_errno(_("unable to create '%s'"), pack_name);
 318                nothread_data.pack_fd = output_fd;
 319        } else {
 320                input_fd = open(pack_name, O_RDONLY);
 321                if (input_fd < 0)
 322                        die_errno(_("cannot open packfile '%s'"), pack_name);
 323                output_fd = -1;
 324                nothread_data.pack_fd = input_fd;
 325        }
 326        git_SHA1_Init(&input_ctx);
 327        return pack_name;
 328}
 329
 330static void parse_pack_header(void)
 331{
 332        struct pack_header *hdr = fill(sizeof(struct pack_header));
 333
 334        /* Header consistency check */
 335        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 336                die(_("pack signature mismatch"));
 337        if (!pack_version_ok(hdr->hdr_version))
 338                die(_("pack version %"PRIu32" unsupported"),
 339                        ntohl(hdr->hdr_version));
 340
 341        nr_objects = ntohl(hdr->hdr_entries);
 342        use(sizeof(struct pack_header));
 343}
 344
 345static NORETURN void bad_object(off_t offset, const char *format,
 346                       ...) __attribute__((format (printf, 2, 3)));
 347
 348static NORETURN void bad_object(off_t offset, const char *format, ...)
 349{
 350        va_list params;
 351        char buf[1024];
 352
 353        va_start(params, format);
 354        vsnprintf(buf, sizeof(buf), format, params);
 355        va_end(params);
 356        die(_("pack has bad object at offset %"PRIuMAX": %s"),
 357            (uintmax_t)offset, buf);
 358}
 359
 360static inline struct thread_local *get_thread_data(void)
 361{
 362#ifndef NO_PTHREADS
 363        if (threads_active)
 364                return pthread_getspecific(key);
 365        assert(!threads_active &&
 366               "This should only be reached when all threads are gone");
 367#endif
 368        return &nothread_data;
 369}
 370
 371#ifndef NO_PTHREADS
 372static void set_thread_data(struct thread_local *data)
 373{
 374        if (threads_active)
 375                pthread_setspecific(key, data);
 376}
 377#endif
 378
 379static struct base_data *alloc_base_data(void)
 380{
 381        struct base_data *base = xcalloc(1, sizeof(struct base_data));
 382        base->ref_last = -1;
 383        base->ofs_last = -1;
 384        return base;
 385}
 386
 387static void free_base_data(struct base_data *c)
 388{
 389        if (c->data) {
 390                free(c->data);
 391                c->data = NULL;
 392                get_thread_data()->base_cache_used -= c->size;
 393        }
 394}
 395
 396static void prune_base_data(struct base_data *retain)
 397{
 398        struct base_data *b;
 399        struct thread_local *data = get_thread_data();
 400        for (b = data->base_cache;
 401             data->base_cache_used > delta_base_cache_limit && b;
 402             b = b->child) {
 403                if (b->data && b != retain)
 404                        free_base_data(b);
 405        }
 406}
 407
 408static void link_base_data(struct base_data *base, struct base_data *c)
 409{
 410        if (base)
 411                base->child = c;
 412        else
 413                get_thread_data()->base_cache = c;
 414
 415        c->base = base;
 416        c->child = NULL;
 417        if (c->data)
 418                get_thread_data()->base_cache_used += c->size;
 419        prune_base_data(c);
 420}
 421
 422static void unlink_base_data(struct base_data *c)
 423{
 424        struct base_data *base = c->base;
 425        if (base)
 426                base->child = NULL;
 427        else
 428                get_thread_data()->base_cache = NULL;
 429        free_base_data(c);
 430}
 431
 432static int is_delta_type(enum object_type type)
 433{
 434        return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 435}
 436
 437static void *unpack_entry_data(off_t offset, unsigned long size,
 438                               enum object_type type, unsigned char *sha1)
 439{
 440        static char fixed_buf[8192];
 441        int status;
 442        git_zstream stream;
 443        void *buf;
 444        git_SHA_CTX c;
 445        char hdr[32];
 446        int hdrlen;
 447
 448        if (!is_delta_type(type)) {
 449                hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), size) + 1;
 450                git_SHA1_Init(&c);
 451                git_SHA1_Update(&c, hdr, hdrlen);
 452        } else
 453                sha1 = NULL;
 454        if (type == OBJ_BLOB && size > big_file_threshold)
 455                buf = fixed_buf;
 456        else
 457                buf = xmallocz(size);
 458
 459        memset(&stream, 0, sizeof(stream));
 460        git_inflate_init(&stream);
 461        stream.next_out = buf;
 462        stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 463
 464        do {
 465                unsigned char *last_out = stream.next_out;
 466                stream.next_in = fill(1);
 467                stream.avail_in = input_len;
 468                status = git_inflate(&stream, 0);
 469                use(input_len - stream.avail_in);
 470                if (sha1)
 471                        git_SHA1_Update(&c, last_out, stream.next_out - last_out);
 472                if (buf == fixed_buf) {
 473                        stream.next_out = buf;
 474                        stream.avail_out = sizeof(fixed_buf);
 475                }
 476        } while (status == Z_OK);
 477        if (stream.total_out != size || status != Z_STREAM_END)
 478                bad_object(offset, _("inflate returned %d"), status);
 479        git_inflate_end(&stream);
 480        if (sha1)
 481                git_SHA1_Final(sha1, &c);
 482        return buf == fixed_buf ? NULL : buf;
 483}
 484
 485static void *unpack_raw_entry(struct object_entry *obj,
 486                              off_t *ofs_offset,
 487                              unsigned char *ref_sha1,
 488                              unsigned char *sha1)
 489{
 490        unsigned char *p;
 491        unsigned long size, c;
 492        off_t base_offset;
 493        unsigned shift;
 494        void *data;
 495
 496        obj->idx.offset = consumed_bytes;
 497        input_crc32 = crc32(0, NULL, 0);
 498
 499        p = fill(1);
 500        c = *p;
 501        use(1);
 502        obj->type = (c >> 4) & 7;
 503        size = (c & 15);
 504        shift = 4;
 505        while (c & 0x80) {
 506                p = fill(1);
 507                c = *p;
 508                use(1);
 509                size += (c & 0x7f) << shift;
 510                shift += 7;
 511        }
 512        obj->size = size;
 513
 514        switch (obj->type) {
 515        case OBJ_REF_DELTA:
 516                hashcpy(ref_sha1, fill(20));
 517                use(20);
 518                break;
 519        case OBJ_OFS_DELTA:
 520                p = fill(1);
 521                c = *p;
 522                use(1);
 523                base_offset = c & 127;
 524                while (c & 128) {
 525                        base_offset += 1;
 526                        if (!base_offset || MSB(base_offset, 7))
 527                                bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 528                        p = fill(1);
 529                        c = *p;
 530                        use(1);
 531                        base_offset = (base_offset << 7) + (c & 127);
 532                }
 533                *ofs_offset = obj->idx.offset - base_offset;
 534                if (*ofs_offset <= 0 || *ofs_offset >= obj->idx.offset)
 535                        bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 536                break;
 537        case OBJ_COMMIT:
 538        case OBJ_TREE:
 539        case OBJ_BLOB:
 540        case OBJ_TAG:
 541                break;
 542        default:
 543                bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 544        }
 545        obj->hdr_size = consumed_bytes - obj->idx.offset;
 546
 547        data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, sha1);
 548        obj->idx.crc32 = input_crc32;
 549        return data;
 550}
 551
 552static void *unpack_data(struct object_entry *obj,
 553                         int (*consume)(const unsigned char *, unsigned long, void *),
 554                         void *cb_data)
 555{
 556        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 557        off_t len = obj[1].idx.offset - from;
 558        unsigned char *data, *inbuf;
 559        git_zstream stream;
 560        int status;
 561
 562        data = xmallocz(consume ? 64*1024 : obj->size);
 563        inbuf = xmalloc((len < 64*1024) ? (int)len : 64*1024);
 564
 565        memset(&stream, 0, sizeof(stream));
 566        git_inflate_init(&stream);
 567        stream.next_out = data;
 568        stream.avail_out = consume ? 64*1024 : obj->size;
 569
 570        do {
 571                ssize_t n = (len < 64*1024) ? (ssize_t)len : 64*1024;
 572                n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 573                if (n < 0)
 574                        die_errno(_("cannot pread pack file"));
 575                if (!n)
 576                        die(Q_("premature end of pack file, %"PRIuMAX" byte missing",
 577                               "premature end of pack file, %"PRIuMAX" bytes missing",
 578                               (unsigned int)len),
 579                            (uintmax_t)len);
 580                from += n;
 581                len -= n;
 582                stream.next_in = inbuf;
 583                stream.avail_in = n;
 584                if (!consume)
 585                        status = git_inflate(&stream, 0);
 586                else {
 587                        do {
 588                                status = git_inflate(&stream, 0);
 589                                if (consume(data, stream.next_out - data, cb_data)) {
 590                                        free(inbuf);
 591                                        free(data);
 592                                        return NULL;
 593                                }
 594                                stream.next_out = data;
 595                                stream.avail_out = 64*1024;
 596                        } while (status == Z_OK && stream.avail_in);
 597                }
 598        } while (len && status == Z_OK && !stream.avail_in);
 599
 600        /* This has been inflated OK when first encountered, so... */
 601        if (status != Z_STREAM_END || stream.total_out != obj->size)
 602                die(_("serious inflate inconsistency"));
 603
 604        git_inflate_end(&stream);
 605        free(inbuf);
 606        if (consume) {
 607                free(data);
 608                data = NULL;
 609        }
 610        return data;
 611}
 612
 613static void *get_data_from_pack(struct object_entry *obj)
 614{
 615        return unpack_data(obj, NULL, NULL);
 616}
 617
 618static int compare_ofs_delta_bases(off_t offset1, off_t offset2,
 619                                   enum object_type type1,
 620                                   enum object_type type2)
 621{
 622        int cmp = type1 - type2;
 623        if (cmp)
 624                return cmp;
 625        return offset1 < offset2 ? -1 :
 626               offset1 > offset2 ?  1 :
 627               0;
 628}
 629
 630static int find_ofs_delta(const off_t offset, enum object_type type)
 631{
 632        int first = 0, last = nr_ofs_deltas;
 633
 634        while (first < last) {
 635                int next = (first + last) / 2;
 636                struct ofs_delta_entry *delta = &ofs_deltas[next];
 637                int cmp;
 638
 639                cmp = compare_ofs_delta_bases(offset, delta->offset,
 640                                              type, objects[delta->obj_no].type);
 641                if (!cmp)
 642                        return next;
 643                if (cmp < 0) {
 644                        last = next;
 645                        continue;
 646                }
 647                first = next+1;
 648        }
 649        return -first-1;
 650}
 651
 652static void find_ofs_delta_children(off_t offset,
 653                                    int *first_index, int *last_index,
 654                                    enum object_type type)
 655{
 656        int first = find_ofs_delta(offset, type);
 657        int last = first;
 658        int end = nr_ofs_deltas - 1;
 659
 660        if (first < 0) {
 661                *first_index = 0;
 662                *last_index = -1;
 663                return;
 664        }
 665        while (first > 0 && ofs_deltas[first - 1].offset == offset)
 666                --first;
 667        while (last < end && ofs_deltas[last + 1].offset == offset)
 668                ++last;
 669        *first_index = first;
 670        *last_index = last;
 671}
 672
 673static int compare_ref_delta_bases(const unsigned char *sha1,
 674                                   const unsigned char *sha2,
 675                                   enum object_type type1,
 676                                   enum object_type type2)
 677{
 678        int cmp = type1 - type2;
 679        if (cmp)
 680                return cmp;
 681        return hashcmp(sha1, sha2);
 682}
 683
 684static int find_ref_delta(const unsigned char *sha1, enum object_type type)
 685{
 686        int first = 0, last = nr_ref_deltas;
 687
 688        while (first < last) {
 689                int next = (first + last) / 2;
 690                struct ref_delta_entry *delta = &ref_deltas[next];
 691                int cmp;
 692
 693                cmp = compare_ref_delta_bases(sha1, delta->sha1,
 694                                              type, objects[delta->obj_no].type);
 695                if (!cmp)
 696                        return next;
 697                if (cmp < 0) {
 698                        last = next;
 699                        continue;
 700                }
 701                first = next+1;
 702        }
 703        return -first-1;
 704}
 705
 706static void find_ref_delta_children(const unsigned char *sha1,
 707                                    int *first_index, int *last_index,
 708                                    enum object_type type)
 709{
 710        int first = find_ref_delta(sha1, type);
 711        int last = first;
 712        int end = nr_ref_deltas - 1;
 713
 714        if (first < 0) {
 715                *first_index = 0;
 716                *last_index = -1;
 717                return;
 718        }
 719        while (first > 0 && !hashcmp(ref_deltas[first - 1].sha1, sha1))
 720                --first;
 721        while (last < end && !hashcmp(ref_deltas[last + 1].sha1, sha1))
 722                ++last;
 723        *first_index = first;
 724        *last_index = last;
 725}
 726
 727struct compare_data {
 728        struct object_entry *entry;
 729        struct git_istream *st;
 730        unsigned char *buf;
 731        unsigned long buf_size;
 732};
 733
 734static int compare_objects(const unsigned char *buf, unsigned long size,
 735                           void *cb_data)
 736{
 737        struct compare_data *data = cb_data;
 738
 739        if (data->buf_size < size) {
 740                free(data->buf);
 741                data->buf = xmalloc(size);
 742                data->buf_size = size;
 743        }
 744
 745        while (size) {
 746                ssize_t len = read_istream(data->st, data->buf, size);
 747                if (len == 0)
 748                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 749                            sha1_to_hex(data->entry->idx.sha1));
 750                if (len < 0)
 751                        die(_("unable to read %s"),
 752                            sha1_to_hex(data->entry->idx.sha1));
 753                if (memcmp(buf, data->buf, len))
 754                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 755                            sha1_to_hex(data->entry->idx.sha1));
 756                size -= len;
 757                buf += len;
 758        }
 759        return 0;
 760}
 761
 762static int check_collison(struct object_entry *entry)
 763{
 764        struct compare_data data;
 765        enum object_type type;
 766        unsigned long size;
 767
 768        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 769                return -1;
 770
 771        memset(&data, 0, sizeof(data));
 772        data.entry = entry;
 773        data.st = open_istream(entry->idx.sha1, &type, &size, NULL);
 774        if (!data.st)
 775                return -1;
 776        if (size != entry->size || type != entry->type)
 777                die(_("SHA1 COLLISION FOUND WITH %s !"),
 778                    sha1_to_hex(entry->idx.sha1));
 779        unpack_data(entry, compare_objects, &data);
 780        close_istream(data.st);
 781        free(data.buf);
 782        return 0;
 783}
 784
 785static void sha1_object(const void *data, struct object_entry *obj_entry,
 786                        unsigned long size, enum object_type type,
 787                        const unsigned char *sha1)
 788{
 789        void *new_data = NULL;
 790        int collision_test_needed = 0;
 791
 792        assert(data || obj_entry);
 793
 794        if (startup_info->have_repository) {
 795                read_lock();
 796                collision_test_needed = has_sha1_file_with_flags(sha1, HAS_SHA1_QUICK);
 797                read_unlock();
 798        }
 799
 800        if (collision_test_needed && !data) {
 801                read_lock();
 802                if (!check_collison(obj_entry))
 803                        collision_test_needed = 0;
 804                read_unlock();
 805        }
 806        if (collision_test_needed) {
 807                void *has_data;
 808                enum object_type has_type;
 809                unsigned long has_size;
 810                read_lock();
 811                has_type = sha1_object_info(sha1, &has_size);
 812                if (has_type < 0)
 813                        die(_("cannot read existing object info %s"), sha1_to_hex(sha1));
 814                if (has_type != type || has_size != size)
 815                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 816                has_data = read_sha1_file(sha1, &has_type, &has_size);
 817                read_unlock();
 818                if (!data)
 819                        data = new_data = get_data_from_pack(obj_entry);
 820                if (!has_data)
 821                        die(_("cannot read existing object %s"), sha1_to_hex(sha1));
 822                if (size != has_size || type != has_type ||
 823                    memcmp(data, has_data, size) != 0)
 824                        die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
 825                free(has_data);
 826        }
 827
 828        if (strict) {
 829                read_lock();
 830                if (type == OBJ_BLOB) {
 831                        struct blob *blob = lookup_blob(sha1);
 832                        if (blob)
 833                                blob->object.flags |= FLAG_CHECKED;
 834                        else
 835                                die(_("invalid blob object %s"), sha1_to_hex(sha1));
 836                } else {
 837                        struct object *obj;
 838                        int eaten;
 839                        void *buf = (void *) data;
 840
 841                        assert(data && "data can only be NULL for large _blobs_");
 842
 843                        /*
 844                         * we do not need to free the memory here, as the
 845                         * buf is deleted by the caller.
 846                         */
 847                        obj = parse_object_buffer(sha1, type, size, buf, &eaten);
 848                        if (!obj)
 849                                die(_("invalid %s"), typename(type));
 850                        if (do_fsck_object &&
 851                            fsck_object(obj, buf, size, &fsck_options))
 852                                die(_("Error in object"));
 853                        if (fsck_walk(obj, NULL, &fsck_options))
 854                                die(_("Not all child objects of %s are reachable"), oid_to_hex(&obj->oid));
 855
 856                        if (obj->type == OBJ_TREE) {
 857                                struct tree *item = (struct tree *) obj;
 858                                item->buffer = NULL;
 859                                obj->parsed = 0;
 860                        }
 861                        if (obj->type == OBJ_COMMIT) {
 862                                struct commit *commit = (struct commit *) obj;
 863                                if (detach_commit_buffer(commit, NULL) != data)
 864                                        die("BUG: parse_object_buffer transmogrified our buffer");
 865                        }
 866                        obj->flags |= FLAG_CHECKED;
 867                }
 868                read_unlock();
 869        }
 870
 871        free(new_data);
 872}
 873
 874/*
 875 * This function is part of find_unresolved_deltas(). There are two
 876 * walkers going in the opposite ways.
 877 *
 878 * The first one in find_unresolved_deltas() traverses down from
 879 * parent node to children, deflating nodes along the way. However,
 880 * memory for deflated nodes is limited by delta_base_cache_limit, so
 881 * at some point parent node's deflated content may be freed.
 882 *
 883 * The second walker is this function, which goes from current node up
 884 * to top parent if necessary to deflate the node. In normal
 885 * situation, its parent node would be already deflated, so it just
 886 * needs to apply delta.
 887 *
 888 * In the worst case scenario, parent node is no longer deflated because
 889 * we're running out of delta_base_cache_limit; we need to re-deflate
 890 * parents, possibly up to the top base.
 891 *
 892 * All deflated objects here are subject to be freed if we exceed
 893 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 894 * just need to make sure the last node is not freed.
 895 */
 896static void *get_base_data(struct base_data *c)
 897{
 898        if (!c->data) {
 899                struct object_entry *obj = c->obj;
 900                struct base_data **delta = NULL;
 901                int delta_nr = 0, delta_alloc = 0;
 902
 903                while (is_delta_type(c->obj->type) && !c->data) {
 904                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 905                        delta[delta_nr++] = c;
 906                        c = c->base;
 907                }
 908                if (!delta_nr) {
 909                        c->data = get_data_from_pack(obj);
 910                        c->size = obj->size;
 911                        get_thread_data()->base_cache_used += c->size;
 912                        prune_base_data(c);
 913                }
 914                for (; delta_nr > 0; delta_nr--) {
 915                        void *base, *raw;
 916                        c = delta[delta_nr - 1];
 917                        obj = c->obj;
 918                        base = get_base_data(c->base);
 919                        raw = get_data_from_pack(obj);
 920                        c->data = patch_delta(
 921                                base, c->base->size,
 922                                raw, obj->size,
 923                                &c->size);
 924                        free(raw);
 925                        if (!c->data)
 926                                bad_object(obj->idx.offset, _("failed to apply delta"));
 927                        get_thread_data()->base_cache_used += c->size;
 928                        prune_base_data(c);
 929                }
 930                free(delta);
 931        }
 932        return c->data;
 933}
 934
 935static void resolve_delta(struct object_entry *delta_obj,
 936                          struct base_data *base, struct base_data *result)
 937{
 938        void *base_data, *delta_data;
 939
 940        if (show_stat) {
 941                int i = delta_obj - objects;
 942                int j = base->obj - objects;
 943                obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 944                deepest_delta_lock();
 945                if (deepest_delta < obj_stat[i].delta_depth)
 946                        deepest_delta = obj_stat[i].delta_depth;
 947                deepest_delta_unlock();
 948                obj_stat[i].base_object_no = j;
 949        }
 950        delta_data = get_data_from_pack(delta_obj);
 951        base_data = get_base_data(base);
 952        result->obj = delta_obj;
 953        result->data = patch_delta(base_data, base->size,
 954                                   delta_data, delta_obj->size, &result->size);
 955        free(delta_data);
 956        if (!result->data)
 957                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 958        hash_sha1_file(result->data, result->size,
 959                       typename(delta_obj->real_type), delta_obj->idx.sha1);
 960        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 961                    delta_obj->idx.sha1);
 962        counter_lock();
 963        nr_resolved_deltas++;
 964        counter_unlock();
 965}
 966
 967/*
 968 * Standard boolean compare-and-swap: atomically check whether "*type" is
 969 * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 970 * and return false.
 971 */
 972static int compare_and_swap_type(signed char *type,
 973                                 enum object_type want,
 974                                 enum object_type set)
 975{
 976        enum object_type old;
 977
 978        type_cas_lock();
 979        old = *type;
 980        if (old == want)
 981                *type = set;
 982        type_cas_unlock();
 983
 984        return old == want;
 985}
 986
 987static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 988                                                  struct base_data *prev_base)
 989{
 990        if (base->ref_last == -1 && base->ofs_last == -1) {
 991                find_ref_delta_children(base->obj->idx.sha1,
 992                                        &base->ref_first, &base->ref_last,
 993                                        OBJ_REF_DELTA);
 994
 995                find_ofs_delta_children(base->obj->idx.offset,
 996                                        &base->ofs_first, &base->ofs_last,
 997                                        OBJ_OFS_DELTA);
 998
 999                if (base->ref_last == -1 && base->ofs_last == -1) {
1000                        free(base->data);
1001                        return NULL;
1002                }
1003
1004                link_base_data(prev_base, base);
1005        }
1006
1007        if (base->ref_first <= base->ref_last) {
1008                struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
1009                struct base_data *result = alloc_base_data();
1010
1011                if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
1012                                           base->obj->real_type))
1013                        die("BUG: child->real_type != OBJ_REF_DELTA");
1014
1015                resolve_delta(child, base, result);
1016                if (base->ref_first == base->ref_last && base->ofs_last == -1)
1017                        free_base_data(base);
1018
1019                base->ref_first++;
1020                return result;
1021        }
1022
1023        if (base->ofs_first <= base->ofs_last) {
1024                struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
1025                struct base_data *result = alloc_base_data();
1026
1027                assert(child->real_type == OBJ_OFS_DELTA);
1028                child->real_type = base->obj->real_type;
1029                resolve_delta(child, base, result);
1030                if (base->ofs_first == base->ofs_last)
1031                        free_base_data(base);
1032
1033                base->ofs_first++;
1034                return result;
1035        }
1036
1037        unlink_base_data(base);
1038        return NULL;
1039}
1040
1041static void find_unresolved_deltas(struct base_data *base)
1042{
1043        struct base_data *new_base, *prev_base = NULL;
1044        for (;;) {
1045                new_base = find_unresolved_deltas_1(base, prev_base);
1046
1047                if (new_base) {
1048                        prev_base = base;
1049                        base = new_base;
1050                } else {
1051                        free(base);
1052                        base = prev_base;
1053                        if (!base)
1054                                return;
1055                        prev_base = base->base;
1056                }
1057        }
1058}
1059
1060static int compare_ofs_delta_entry(const void *a, const void *b)
1061{
1062        const struct ofs_delta_entry *delta_a = a;
1063        const struct ofs_delta_entry *delta_b = b;
1064
1065        return delta_a->offset < delta_b->offset ? -1 :
1066               delta_a->offset > delta_b->offset ?  1 :
1067               0;
1068}
1069
1070static int compare_ref_delta_entry(const void *a, const void *b)
1071{
1072        const struct ref_delta_entry *delta_a = a;
1073        const struct ref_delta_entry *delta_b = b;
1074
1075        return hashcmp(delta_a->sha1, delta_b->sha1);
1076}
1077
1078static void resolve_base(struct object_entry *obj)
1079{
1080        struct base_data *base_obj = alloc_base_data();
1081        base_obj->obj = obj;
1082        base_obj->data = NULL;
1083        find_unresolved_deltas(base_obj);
1084}
1085
1086#ifndef NO_PTHREADS
1087static void *threaded_second_pass(void *data)
1088{
1089        set_thread_data(data);
1090        for (;;) {
1091                int i;
1092                counter_lock();
1093                display_progress(progress, nr_resolved_deltas);
1094                counter_unlock();
1095                work_lock();
1096                while (nr_dispatched < nr_objects &&
1097                       is_delta_type(objects[nr_dispatched].type))
1098                        nr_dispatched++;
1099                if (nr_dispatched >= nr_objects) {
1100                        work_unlock();
1101                        break;
1102                }
1103                i = nr_dispatched++;
1104                work_unlock();
1105
1106                resolve_base(&objects[i]);
1107        }
1108        return NULL;
1109}
1110#endif
1111
1112/*
1113 * First pass:
1114 * - find locations of all objects;
1115 * - calculate SHA1 of all non-delta objects;
1116 * - remember base (SHA1 or offset) for all deltas.
1117 */
1118static void parse_pack_objects(unsigned char *sha1)
1119{
1120        int i, nr_delays = 0;
1121        struct ofs_delta_entry *ofs_delta = ofs_deltas;
1122        unsigned char ref_delta_sha1[20];
1123        struct stat st;
1124
1125        if (verbose)
1126                progress = start_progress(
1127                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1128                                nr_objects);
1129        for (i = 0; i < nr_objects; i++) {
1130                struct object_entry *obj = &objects[i];
1131                void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1132                                              ref_delta_sha1, obj->idx.sha1);
1133                obj->real_type = obj->type;
1134                if (obj->type == OBJ_OFS_DELTA) {
1135                        nr_ofs_deltas++;
1136                        ofs_delta->obj_no = i;
1137                        ofs_delta++;
1138                } else if (obj->type == OBJ_REF_DELTA) {
1139                        ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1140                        hashcpy(ref_deltas[nr_ref_deltas].sha1, ref_delta_sha1);
1141                        ref_deltas[nr_ref_deltas].obj_no = i;
1142                        nr_ref_deltas++;
1143                } else if (!data) {
1144                        /* large blobs, check later */
1145                        obj->real_type = OBJ_BAD;
1146                        nr_delays++;
1147                } else
1148                        sha1_object(data, NULL, obj->size, obj->type, obj->idx.sha1);
1149                free(data);
1150                display_progress(progress, i+1);
1151        }
1152        objects[i].idx.offset = consumed_bytes;
1153        stop_progress(&progress);
1154
1155        /* Check pack integrity */
1156        flush();
1157        git_SHA1_Final(sha1, &input_ctx);
1158        if (hashcmp(fill(20), sha1))
1159                die(_("pack is corrupted (SHA1 mismatch)"));
1160        use(20);
1161
1162        /* If input_fd is a file, we should have reached its end now. */
1163        if (fstat(input_fd, &st))
1164                die_errno(_("cannot fstat packfile"));
1165        if (S_ISREG(st.st_mode) &&
1166                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1167                die(_("pack has junk at the end"));
1168
1169        for (i = 0; i < nr_objects; i++) {
1170                struct object_entry *obj = &objects[i];
1171                if (obj->real_type != OBJ_BAD)
1172                        continue;
1173                obj->real_type = obj->type;
1174                sha1_object(NULL, obj, obj->size, obj->type, obj->idx.sha1);
1175                nr_delays--;
1176        }
1177        if (nr_delays)
1178                die(_("confusion beyond insanity in parse_pack_objects()"));
1179}
1180
1181/*
1182 * Second pass:
1183 * - for all non-delta objects, look if it is used as a base for
1184 *   deltas;
1185 * - if used as a base, uncompress the object and apply all deltas,
1186 *   recursively checking if the resulting object is used as a base
1187 *   for some more deltas.
1188 */
1189static void resolve_deltas(void)
1190{
1191        int i;
1192
1193        if (!nr_ofs_deltas && !nr_ref_deltas)
1194                return;
1195
1196        /* Sort deltas by base SHA1/offset for fast searching */
1197        QSORT(ofs_deltas, nr_ofs_deltas, compare_ofs_delta_entry);
1198        QSORT(ref_deltas, nr_ref_deltas, compare_ref_delta_entry);
1199
1200        if (verbose || show_resolving_progress)
1201                progress = start_progress(_("Resolving deltas"),
1202                                          nr_ref_deltas + nr_ofs_deltas);
1203
1204#ifndef NO_PTHREADS
1205        nr_dispatched = 0;
1206        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1207                init_thread();
1208                for (i = 0; i < nr_threads; i++) {
1209                        int ret = pthread_create(&thread_data[i].thread, NULL,
1210                                                 threaded_second_pass, thread_data + i);
1211                        if (ret)
1212                                die(_("unable to create thread: %s"),
1213                                    strerror(ret));
1214                }
1215                for (i = 0; i < nr_threads; i++)
1216                        pthread_join(thread_data[i].thread, NULL);
1217                cleanup_thread();
1218                return;
1219        }
1220#endif
1221
1222        for (i = 0; i < nr_objects; i++) {
1223                struct object_entry *obj = &objects[i];
1224
1225                if (is_delta_type(obj->type))
1226                        continue;
1227                resolve_base(obj);
1228                display_progress(progress, nr_resolved_deltas);
1229        }
1230}
1231
1232/*
1233 * Third pass:
1234 * - append objects to convert thin pack to full pack if required
1235 * - write the final 20-byte SHA-1
1236 */
1237static void fix_unresolved_deltas(struct sha1file *f);
1238static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
1239{
1240        if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1241                stop_progress(&progress);
1242                /* Flush remaining pack final 20-byte SHA1. */
1243                flush();
1244                return;
1245        }
1246
1247        if (fix_thin_pack) {
1248                struct sha1file *f;
1249                unsigned char read_sha1[20], tail_sha1[20];
1250                struct strbuf msg = STRBUF_INIT;
1251                int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1252                int nr_objects_initial = nr_objects;
1253                if (nr_unresolved <= 0)
1254                        die(_("confusion beyond insanity"));
1255                REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1256                memset(objects + nr_objects + 1, 0,
1257                       nr_unresolved * sizeof(*objects));
1258                f = sha1fd(output_fd, curr_pack);
1259                fix_unresolved_deltas(f);
1260                strbuf_addf(&msg, Q_("completed with %d local object",
1261                                     "completed with %d local objects",
1262                                     nr_objects - nr_objects_initial),
1263                            nr_objects - nr_objects_initial);
1264                stop_progress_msg(&progress, msg.buf);
1265                strbuf_release(&msg);
1266                sha1close(f, tail_sha1, 0);
1267                hashcpy(read_sha1, pack_sha1);
1268                fixup_pack_header_footer(output_fd, pack_sha1,
1269                                         curr_pack, nr_objects,
1270                                         read_sha1, consumed_bytes-20);
1271                if (hashcmp(read_sha1, tail_sha1) != 0)
1272                        die(_("Unexpected tail checksum for %s "
1273                              "(disk corruption?)"), curr_pack);
1274        }
1275        if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1276                die(Q_("pack has %d unresolved delta",
1277                       "pack has %d unresolved deltas",
1278                       nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1279                    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1280}
1281
1282static int write_compressed(struct sha1file *f, void *in, unsigned int size)
1283{
1284        git_zstream stream;
1285        int status;
1286        unsigned char outbuf[4096];
1287
1288        git_deflate_init(&stream, zlib_compression_level);
1289        stream.next_in = in;
1290        stream.avail_in = size;
1291
1292        do {
1293                stream.next_out = outbuf;
1294                stream.avail_out = sizeof(outbuf);
1295                status = git_deflate(&stream, Z_FINISH);
1296                sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
1297        } while (status == Z_OK);
1298
1299        if (status != Z_STREAM_END)
1300                die(_("unable to deflate appended object (%d)"), status);
1301        size = stream.total_out;
1302        git_deflate_end(&stream);
1303        return size;
1304}
1305
1306static struct object_entry *append_obj_to_pack(struct sha1file *f,
1307                               const unsigned char *sha1, void *buf,
1308                               unsigned long size, enum object_type type)
1309{
1310        struct object_entry *obj = &objects[nr_objects++];
1311        unsigned char header[10];
1312        unsigned long s = size;
1313        int n = 0;
1314        unsigned char c = (type << 4) | (s & 15);
1315        s >>= 4;
1316        while (s) {
1317                header[n++] = c | 0x80;
1318                c = s & 0x7f;
1319                s >>= 7;
1320        }
1321        header[n++] = c;
1322        crc32_begin(f);
1323        sha1write(f, header, n);
1324        obj[0].size = size;
1325        obj[0].hdr_size = n;
1326        obj[0].type = type;
1327        obj[0].real_type = type;
1328        obj[1].idx.offset = obj[0].idx.offset + n;
1329        obj[1].idx.offset += write_compressed(f, buf, size);
1330        obj[0].idx.crc32 = crc32_end(f);
1331        sha1flush(f);
1332        hashcpy(obj->idx.sha1, sha1);
1333        return obj;
1334}
1335
1336static int delta_pos_compare(const void *_a, const void *_b)
1337{
1338        struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1339        struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1340        return a->obj_no - b->obj_no;
1341}
1342
1343static void fix_unresolved_deltas(struct sha1file *f)
1344{
1345        struct ref_delta_entry **sorted_by_pos;
1346        int i;
1347
1348        /*
1349         * Since many unresolved deltas may well be themselves base objects
1350         * for more unresolved deltas, we really want to include the
1351         * smallest number of base objects that would cover as much delta
1352         * as possible by picking the
1353         * trunc deltas first, allowing for other deltas to resolve without
1354         * additional base objects.  Since most base objects are to be found
1355         * before deltas depending on them, a good heuristic is to start
1356         * resolving deltas in the same order as their position in the pack.
1357         */
1358        ALLOC_ARRAY(sorted_by_pos, nr_ref_deltas);
1359        for (i = 0; i < nr_ref_deltas; i++)
1360                sorted_by_pos[i] = &ref_deltas[i];
1361        QSORT(sorted_by_pos, nr_ref_deltas, delta_pos_compare);
1362
1363        for (i = 0; i < nr_ref_deltas; i++) {
1364                struct ref_delta_entry *d = sorted_by_pos[i];
1365                enum object_type type;
1366                struct base_data *base_obj = alloc_base_data();
1367
1368                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1369                        continue;
1370                base_obj->data = read_sha1_file(d->sha1, &type, &base_obj->size);
1371                if (!base_obj->data)
1372                        continue;
1373
1374                if (check_sha1_signature(d->sha1, base_obj->data,
1375                                base_obj->size, typename(type)))
1376                        die(_("local object %s is corrupt"), sha1_to_hex(d->sha1));
1377                base_obj->obj = append_obj_to_pack(f, d->sha1,
1378                                        base_obj->data, base_obj->size, type);
1379                find_unresolved_deltas(base_obj);
1380                display_progress(progress, nr_resolved_deltas);
1381        }
1382        free(sorted_by_pos);
1383}
1384
1385static void final(const char *final_pack_name, const char *curr_pack_name,
1386                  const char *final_index_name, const char *curr_index_name,
1387                  const char *keep_name, const char *keep_msg,
1388                  unsigned char *sha1)
1389{
1390        const char *report = "pack";
1391        struct strbuf pack_name = STRBUF_INIT;
1392        struct strbuf index_name = STRBUF_INIT;
1393        struct strbuf keep_name_buf = STRBUF_INIT;
1394        int err;
1395
1396        if (!from_stdin) {
1397                close(input_fd);
1398        } else {
1399                fsync_or_die(output_fd, curr_pack_name);
1400                err = close(output_fd);
1401                if (err)
1402                        die_errno(_("error while closing pack file"));
1403        }
1404
1405        if (keep_msg) {
1406                int keep_fd, keep_msg_len = strlen(keep_msg);
1407
1408                if (!keep_name)
1409                        keep_name = odb_pack_name(&keep_name_buf, sha1, "keep");
1410
1411                keep_fd = odb_pack_keep(keep_name);
1412                if (keep_fd < 0) {
1413                        if (errno != EEXIST)
1414                                die_errno(_("cannot write keep file '%s'"),
1415                                          keep_name);
1416                } else {
1417                        if (keep_msg_len > 0) {
1418                                write_or_die(keep_fd, keep_msg, keep_msg_len);
1419                                write_or_die(keep_fd, "\n", 1);
1420                        }
1421                        if (close(keep_fd) != 0)
1422                                die_errno(_("cannot close written keep file '%s'"),
1423                                          keep_name);
1424                        report = "keep";
1425                }
1426        }
1427
1428        if (final_pack_name != curr_pack_name) {
1429                if (!final_pack_name)
1430                        final_pack_name = odb_pack_name(&pack_name, sha1, "pack");
1431                if (finalize_object_file(curr_pack_name, final_pack_name))
1432                        die(_("cannot store pack file"));
1433        } else if (from_stdin)
1434                chmod(final_pack_name, 0444);
1435
1436        if (final_index_name != curr_index_name) {
1437                if (!final_index_name)
1438                        final_index_name = odb_pack_name(&index_name, sha1, "idx");
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        strbuf_release(&index_name);
1466        strbuf_release(&pack_name);
1467        strbuf_release(&keep_name_buf);
1468}
1469
1470static int git_index_pack_config(const char *k, const char *v, void *cb)
1471{
1472        struct pack_idx_option *opts = cb;
1473
1474        if (!strcmp(k, "pack.indexversion")) {
1475                opts->version = git_config_int(k, v);
1476                if (opts->version > 2)
1477                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1478                return 0;
1479        }
1480        if (!strcmp(k, "pack.threads")) {
1481                nr_threads = git_config_int(k, v);
1482                if (nr_threads < 0)
1483                        die(_("invalid number of threads specified (%d)"),
1484                            nr_threads);
1485#ifdef NO_PTHREADS
1486                if (nr_threads != 1)
1487                        warning(_("no threads support, ignoring %s"), k);
1488                nr_threads = 1;
1489#endif
1490                return 0;
1491        }
1492        return git_default_config(k, v, cb);
1493}
1494
1495static int cmp_uint32(const void *a_, const void *b_)
1496{
1497        uint32_t a = *((uint32_t *)a_);
1498        uint32_t b = *((uint32_t *)b_);
1499
1500        return (a < b) ? -1 : (a != b);
1501}
1502
1503static void read_v2_anomalous_offsets(struct packed_git *p,
1504                                      struct pack_idx_option *opts)
1505{
1506        const uint32_t *idx1, *idx2;
1507        uint32_t i;
1508
1509        /* The address of the 4-byte offset table */
1510        idx1 = (((const uint32_t *)p->index_data)
1511                + 2 /* 8-byte header */
1512                + 256 /* fan out */
1513                + 5 * p->num_objects /* 20-byte SHA-1 table */
1514                + p->num_objects /* CRC32 table */
1515                );
1516
1517        /* The address of the 8-byte offset table */
1518        idx2 = idx1 + p->num_objects;
1519
1520        for (i = 0; i < p->num_objects; i++) {
1521                uint32_t off = ntohl(idx1[i]);
1522                if (!(off & 0x80000000))
1523                        continue;
1524                off = off & 0x7fffffff;
1525                check_pack_index_ptr(p, &idx2[off * 2]);
1526                if (idx2[off * 2])
1527                        continue;
1528                /*
1529                 * The real offset is ntohl(idx2[off * 2]) in high 4
1530                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1531                 * octets.  But idx2[off * 2] is Zero!!!
1532                 */
1533                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1534                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1535        }
1536
1537        QSORT(opts->anomaly, opts->anomaly_nr, cmp_uint32);
1538}
1539
1540static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1541{
1542        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1543
1544        if (!p)
1545                die(_("Cannot open existing pack file '%s'"), pack_name);
1546        if (open_pack_index(p))
1547                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1548
1549        /* Read the attributes from the existing idx file */
1550        opts->version = p->index_version;
1551
1552        if (opts->version == 2)
1553                read_v2_anomalous_offsets(p, opts);
1554
1555        /*
1556         * Get rid of the idx file as we do not need it anymore.
1557         * NEEDSWORK: extract this bit from free_pack_by_name() in
1558         * sha1_file.c, perhaps?  It shouldn't matter very much as we
1559         * know we haven't installed this pack (hence we never have
1560         * read anything from it).
1561         */
1562        close_pack_index(p);
1563        free(p);
1564}
1565
1566static void show_pack_info(int stat_only)
1567{
1568        int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1569        unsigned long *chain_histogram = NULL;
1570
1571        if (deepest_delta)
1572                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1573
1574        for (i = 0; i < nr_objects; i++) {
1575                struct object_entry *obj = &objects[i];
1576
1577                if (is_delta_type(obj->type))
1578                        chain_histogram[obj_stat[i].delta_depth - 1]++;
1579                if (stat_only)
1580                        continue;
1581                printf("%s %-6s %lu %lu %"PRIuMAX,
1582                       sha1_to_hex(obj->idx.sha1),
1583                       typename(obj->real_type), obj->size,
1584                       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1585                       (uintmax_t)obj->idx.offset);
1586                if (is_delta_type(obj->type)) {
1587                        struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1588                        printf(" %u %s", obj_stat[i].delta_depth, sha1_to_hex(bobj->idx.sha1));
1589                }
1590                putchar('\n');
1591        }
1592
1593        if (baseobjects)
1594                printf_ln(Q_("non delta: %d object",
1595                             "non delta: %d objects",
1596                             baseobjects),
1597                          baseobjects);
1598        for (i = 0; i < deepest_delta; i++) {
1599                if (!chain_histogram[i])
1600                        continue;
1601                printf_ln(Q_("chain length = %d: %lu object",
1602                             "chain length = %d: %lu objects",
1603                             chain_histogram[i]),
1604                          i + 1,
1605                          chain_histogram[i]);
1606        }
1607}
1608
1609static const char *derive_filename(const char *pack_name, const char *suffix,
1610                                   struct strbuf *buf)
1611{
1612        size_t len;
1613        if (!strip_suffix(pack_name, ".pack", &len))
1614                die(_("packfile name '%s' does not end with '.pack'"),
1615                    pack_name);
1616        strbuf_add(buf, pack_name, len);
1617        strbuf_addstr(buf, suffix);
1618        return buf->buf;
1619}
1620
1621int cmd_index_pack(int argc, const char **argv, const char *prefix)
1622{
1623        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1624        const char *curr_index;
1625        const char *index_name = NULL, *pack_name = NULL;
1626        const char *keep_name = NULL, *keep_msg = NULL;
1627        struct strbuf index_name_buf = STRBUF_INIT,
1628                      keep_name_buf = STRBUF_INIT;
1629        struct pack_idx_entry **idx_objects;
1630        struct pack_idx_option opts;
1631        unsigned char pack_sha1[20];
1632        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1633        int report_end_of_input = 0;
1634
1635        if (argc == 2 && !strcmp(argv[1], "-h"))
1636                usage(index_pack_usage);
1637
1638        check_replace_refs = 0;
1639        fsck_options.walk = mark_link;
1640
1641        reset_pack_idx_option(&opts);
1642        git_config(git_index_pack_config, &opts);
1643        if (prefix && chdir(prefix))
1644                die(_("Cannot come back to cwd"));
1645
1646        for (i = 1; i < argc; i++) {
1647                const char *arg = argv[i];
1648
1649                if (*arg == '-') {
1650                        if (!strcmp(arg, "--stdin")) {
1651                                from_stdin = 1;
1652                        } else if (!strcmp(arg, "--fix-thin")) {
1653                                fix_thin_pack = 1;
1654                        } else if (!strcmp(arg, "--strict")) {
1655                                strict = 1;
1656                                do_fsck_object = 1;
1657                        } else if (skip_prefix(arg, "--strict=", &arg)) {
1658                                strict = 1;
1659                                do_fsck_object = 1;
1660                                fsck_set_msg_types(&fsck_options, arg);
1661                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1662                                strict = 1;
1663                                check_self_contained_and_connected = 1;
1664                        } else if (!strcmp(arg, "--verify")) {
1665                                verify = 1;
1666                        } else if (!strcmp(arg, "--verify-stat")) {
1667                                verify = 1;
1668                                show_stat = 1;
1669                        } else if (!strcmp(arg, "--verify-stat-only")) {
1670                                verify = 1;
1671                                show_stat = 1;
1672                                stat_only = 1;
1673                        } else if (!strcmp(arg, "--keep")) {
1674                                keep_msg = "";
1675                        } else if (starts_with(arg, "--keep=")) {
1676                                keep_msg = arg + 7;
1677                        } else if (starts_with(arg, "--threads=")) {
1678                                char *end;
1679                                nr_threads = strtoul(arg+10, &end, 0);
1680                                if (!arg[10] || *end || nr_threads < 0)
1681                                        usage(index_pack_usage);
1682#ifdef NO_PTHREADS
1683                                if (nr_threads != 1)
1684                                        warning(_("no threads support, "
1685                                                  "ignoring %s"), arg);
1686                                nr_threads = 1;
1687#endif
1688                        } else if (starts_with(arg, "--pack_header=")) {
1689                                struct pack_header *hdr;
1690                                char *c;
1691
1692                                hdr = (struct pack_header *)input_buffer;
1693                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1694                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1695                                if (*c != ',')
1696                                        die(_("bad %s"), arg);
1697                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1698                                if (*c)
1699                                        die(_("bad %s"), arg);
1700                                input_len = sizeof(*hdr);
1701                        } else if (!strcmp(arg, "-v")) {
1702                                verbose = 1;
1703                        } else if (!strcmp(arg, "--show-resolving-progress")) {
1704                                show_resolving_progress = 1;
1705                        } else if (!strcmp(arg, "--report-end-of-input")) {
1706                                report_end_of_input = 1;
1707                        } else if (!strcmp(arg, "-o")) {
1708                                if (index_name || (i+1) >= argc)
1709                                        usage(index_pack_usage);
1710                                index_name = argv[++i];
1711                        } else if (starts_with(arg, "--index-version=")) {
1712                                char *c;
1713                                opts.version = strtoul(arg + 16, &c, 10);
1714                                if (opts.version > 2)
1715                                        die(_("bad %s"), arg);
1716                                if (*c == ',')
1717                                        opts.off32_limit = strtoul(c+1, &c, 0);
1718                                if (*c || opts.off32_limit & 0x80000000)
1719                                        die(_("bad %s"), arg);
1720                        } else if (skip_prefix(arg, "--max-input-size=", &arg)) {
1721                                max_input_size = strtoumax(arg, NULL, 10);
1722                        } else
1723                                usage(index_pack_usage);
1724                        continue;
1725                }
1726
1727                if (pack_name)
1728                        usage(index_pack_usage);
1729                pack_name = arg;
1730        }
1731
1732        if (!pack_name && !from_stdin)
1733                usage(index_pack_usage);
1734        if (fix_thin_pack && !from_stdin)
1735                die(_("--fix-thin cannot be used without --stdin"));
1736        if (from_stdin && !startup_info->have_repository)
1737                die(_("--stdin requires a git repository"));
1738        if (!index_name && pack_name)
1739                index_name = derive_filename(pack_name, ".idx", &index_name_buf);
1740        if (keep_msg && !keep_name && pack_name)
1741                keep_name = derive_filename(pack_name, ".keep", &keep_name_buf);
1742
1743        if (verify) {
1744                if (!index_name)
1745                        die(_("--verify with no packfile name given"));
1746                read_idx_option(&opts, index_name);
1747                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1748        }
1749        if (strict)
1750                opts.flags |= WRITE_IDX_STRICT;
1751
1752#ifndef NO_PTHREADS
1753        if (!nr_threads) {
1754                nr_threads = online_cpus();
1755                /* An experiment showed that more threads does not mean faster */
1756                if (nr_threads > 3)
1757                        nr_threads = 3;
1758        }
1759#endif
1760
1761        curr_pack = open_pack_file(pack_name);
1762        parse_pack_header();
1763        objects = xcalloc(st_add(nr_objects, 1), sizeof(struct object_entry));
1764        if (show_stat)
1765                obj_stat = xcalloc(st_add(nr_objects, 1), sizeof(struct object_stat));
1766        ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
1767        parse_pack_objects(pack_sha1);
1768        if (report_end_of_input)
1769                write_in_full(2, "\0", 1);
1770        resolve_deltas();
1771        conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
1772        free(ofs_deltas);
1773        free(ref_deltas);
1774        if (strict)
1775                foreign_nr = check_objects();
1776
1777        if (show_stat)
1778                show_pack_info(stat_only);
1779
1780        ALLOC_ARRAY(idx_objects, nr_objects);
1781        for (i = 0; i < nr_objects; i++)
1782                idx_objects[i] = &objects[i].idx;
1783        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
1784        free(idx_objects);
1785
1786        if (!verify)
1787                final(pack_name, curr_pack,
1788                      index_name, curr_index,
1789                      keep_name, keep_msg,
1790                      pack_sha1);
1791        else
1792                close(input_fd);
1793        free(objects);
1794        strbuf_release(&index_name_buf);
1795        strbuf_release(&keep_name_buf);
1796        if (pack_name == NULL)
1797                free((void *) curr_pack);
1798        if (index_name == NULL)
1799                free((void *) curr_index);
1800
1801        /*
1802         * Let the caller know this pack is not self contained
1803         */
1804        if (check_self_contained_and_connected && foreign_nr)
1805                return 1;
1806
1807        return 0;
1808}