builtin / index-pack.con commit sha1_file: convert sha1_object_info* to object_id (abef902)
   1#include "builtin.h"
   2#include "config.h"
   3#include "delta.h"
   4#include "pack.h"
   5#include "csum-file.h"
   6#include "blob.h"
   7#include "commit.h"
   8#include "tag.h"
   9#include "tree.h"
  10#include "progress.h"
  11#include "fsck.h"
  12#include "exec_cmd.h"
  13#include "streaming.h"
  14#include "thread-utils.h"
  15#include "packfile.h"
  16
  17static const char index_pack_usage[] =
  18"git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
  19
  20struct object_entry {
  21        struct pack_idx_entry idx;
  22        unsigned long size;
  23        unsigned char hdr_size;
  24        signed char type;
  25        signed char real_type;
  26};
  27
  28struct object_stat {
  29        unsigned delta_depth;
  30        int base_object_no;
  31};
  32
  33struct base_data {
  34        struct base_data *base;
  35        struct base_data *child;
  36        struct object_entry *obj;
  37        void *data;
  38        unsigned long size;
  39        int ref_first, ref_last;
  40        int ofs_first, ofs_last;
  41};
  42
  43struct thread_local {
  44#ifndef NO_PTHREADS
  45        pthread_t thread;
  46#endif
  47        struct base_data *base_cache;
  48        size_t base_cache_used;
  49        int pack_fd;
  50};
  51
  52#define FLAG_LINK (1u<<20)
  53#define FLAG_CHECKED (1u<<21)
  54
  55struct ofs_delta_entry {
  56        off_t offset;
  57        int obj_no;
  58};
  59
  60struct ref_delta_entry {
  61        struct object_id oid;
  62        int obj_no;
  63};
  64
  65static struct object_entry *objects;
  66static struct object_stat *obj_stat;
  67static struct ofs_delta_entry *ofs_deltas;
  68static struct ref_delta_entry *ref_deltas;
  69static struct thread_local nothread_data;
  70static int nr_objects;
  71static int nr_ofs_deltas;
  72static int nr_ref_deltas;
  73static int ref_deltas_alloc;
  74static int nr_resolved_deltas;
  75static int nr_threads;
  76
  77static int from_stdin;
  78static int strict;
  79static int do_fsck_object;
  80static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
  81static int verbose;
  82static int show_resolving_progress;
  83static int show_stat;
  84static int check_self_contained_and_connected;
  85
  86static struct progress *progress;
  87
  88/* We always read in 4kB chunks. */
  89static unsigned char input_buffer[4096];
  90static unsigned int input_offset, input_len;
  91static off_t consumed_bytes;
  92static off_t max_input_size;
  93static unsigned deepest_delta;
  94static git_hash_ctx input_ctx;
  95static uint32_t input_crc32;
  96static int input_fd, output_fd;
  97static const char *curr_pack;
  98
  99#ifndef NO_PTHREADS
 100
 101static struct thread_local *thread_data;
 102static int nr_dispatched;
 103static int threads_active;
 104
 105static pthread_mutex_t read_mutex;
 106#define read_lock()             lock_mutex(&read_mutex)
 107#define read_unlock()           unlock_mutex(&read_mutex)
 108
 109static pthread_mutex_t counter_mutex;
 110#define counter_lock()          lock_mutex(&counter_mutex)
 111#define counter_unlock()        unlock_mutex(&counter_mutex)
 112
 113static pthread_mutex_t work_mutex;
 114#define work_lock()             lock_mutex(&work_mutex)
 115#define work_unlock()           unlock_mutex(&work_mutex)
 116
 117static pthread_mutex_t deepest_delta_mutex;
 118#define deepest_delta_lock()    lock_mutex(&deepest_delta_mutex)
 119#define deepest_delta_unlock()  unlock_mutex(&deepest_delta_mutex)
 120
 121static pthread_mutex_t type_cas_mutex;
 122#define type_cas_lock()         lock_mutex(&type_cas_mutex)
 123#define type_cas_unlock()       unlock_mutex(&type_cas_mutex)
 124
 125static pthread_key_t key;
 126
 127static inline void lock_mutex(pthread_mutex_t *mutex)
 128{
 129        if (threads_active)
 130                pthread_mutex_lock(mutex);
 131}
 132
 133static inline void unlock_mutex(pthread_mutex_t *mutex)
 134{
 135        if (threads_active)
 136                pthread_mutex_unlock(mutex);
 137}
 138
 139/*
 140 * Mutex and conditional variable can't be statically-initialized on Windows.
 141 */
 142static void init_thread(void)
 143{
 144        int i;
 145        init_recursive_mutex(&read_mutex);
 146        pthread_mutex_init(&counter_mutex, NULL);
 147        pthread_mutex_init(&work_mutex, NULL);
 148        pthread_mutex_init(&type_cas_mutex, NULL);
 149        if (show_stat)
 150                pthread_mutex_init(&deepest_delta_mutex, NULL);
 151        pthread_key_create(&key, NULL);
 152        thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 153        for (i = 0; i < nr_threads; i++) {
 154                thread_data[i].pack_fd = open(curr_pack, O_RDONLY);
 155                if (thread_data[i].pack_fd == -1)
 156                        die_errno(_("unable to open %s"), curr_pack);
 157        }
 158
 159        threads_active = 1;
 160}
 161
 162static void cleanup_thread(void)
 163{
 164        int i;
 165        if (!threads_active)
 166                return;
 167        threads_active = 0;
 168        pthread_mutex_destroy(&read_mutex);
 169        pthread_mutex_destroy(&counter_mutex);
 170        pthread_mutex_destroy(&work_mutex);
 171        pthread_mutex_destroy(&type_cas_mutex);
 172        if (show_stat)
 173                pthread_mutex_destroy(&deepest_delta_mutex);
 174        for (i = 0; i < nr_threads; i++)
 175                close(thread_data[i].pack_fd);
 176        pthread_key_delete(key);
 177        free(thread_data);
 178}
 179
 180#else
 181
 182#define read_lock()
 183#define read_unlock()
 184
 185#define counter_lock()
 186#define counter_unlock()
 187
 188#define work_lock()
 189#define work_unlock()
 190
 191#define deepest_delta_lock()
 192#define deepest_delta_unlock()
 193
 194#define type_cas_lock()
 195#define type_cas_unlock()
 196
 197#endif
 198
 199
 200static int mark_link(struct object *obj, int type, void *data, struct fsck_options *options)
 201{
 202        if (!obj)
 203                return -1;
 204
 205        if (type != OBJ_ANY && obj->type != type)
 206                die(_("object type mismatch at %s"), oid_to_hex(&obj->oid));
 207
 208        obj->flags |= FLAG_LINK;
 209        return 0;
 210}
 211
 212/* The content of each linked object must have been checked
 213   or it must be already present in the object database */
 214static unsigned check_object(struct object *obj)
 215{
 216        if (!obj)
 217                return 0;
 218
 219        if (!(obj->flags & FLAG_LINK))
 220                return 0;
 221
 222        if (!(obj->flags & FLAG_CHECKED)) {
 223                unsigned long size;
 224                int type = oid_object_info(&obj->oid, &size);
 225                if (type <= 0)
 226                        die(_("did not receive expected object %s"),
 227                              oid_to_hex(&obj->oid));
 228                if (type != obj->type)
 229                        die(_("object %s: expected type %s, found %s"),
 230                            oid_to_hex(&obj->oid),
 231                            type_name(obj->type), type_name(type));
 232                obj->flags |= FLAG_CHECKED;
 233                return 1;
 234        }
 235
 236        return 0;
 237}
 238
 239static unsigned check_objects(void)
 240{
 241        unsigned i, max, foreign_nr = 0;
 242
 243        max = get_max_object_index();
 244        for (i = 0; i < max; i++)
 245                foreign_nr += check_object(get_indexed_object(i));
 246        return foreign_nr;
 247}
 248
 249
 250/* Discard current buffer used content. */
 251static void flush(void)
 252{
 253        if (input_offset) {
 254                if (output_fd >= 0)
 255                        write_or_die(output_fd, input_buffer, input_offset);
 256                the_hash_algo->update_fn(&input_ctx, input_buffer, input_offset);
 257                memmove(input_buffer, input_buffer + input_offset, input_len);
 258                input_offset = 0;
 259        }
 260}
 261
 262/*
 263 * Make sure at least "min" bytes are available in the buffer, and
 264 * return the pointer to the buffer.
 265 */
 266static void *fill(int min)
 267{
 268        if (min <= input_len)
 269                return input_buffer + input_offset;
 270        if (min > sizeof(input_buffer))
 271                die(Q_("cannot fill %d byte",
 272                       "cannot fill %d bytes",
 273                       min),
 274                    min);
 275        flush();
 276        do {
 277                ssize_t ret = xread(input_fd, input_buffer + input_len,
 278                                sizeof(input_buffer) - input_len);
 279                if (ret <= 0) {
 280                        if (!ret)
 281                                die(_("early EOF"));
 282                        die_errno(_("read error on input"));
 283                }
 284                input_len += ret;
 285                if (from_stdin)
 286                        display_throughput(progress, consumed_bytes + input_len);
 287        } while (input_len < min);
 288        return input_buffer;
 289}
 290
 291static void use(int bytes)
 292{
 293        if (bytes > input_len)
 294                die(_("used more bytes than were available"));
 295        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 296        input_len -= bytes;
 297        input_offset += bytes;
 298
 299        /* make sure off_t is sufficiently large not to wrap */
 300        if (signed_add_overflows(consumed_bytes, bytes))
 301                die(_("pack too large for current definition of off_t"));
 302        consumed_bytes += bytes;
 303        if (max_input_size && consumed_bytes > max_input_size)
 304                die(_("pack exceeds maximum allowed size"));
 305}
 306
 307static const char *open_pack_file(const char *pack_name)
 308{
 309        if (from_stdin) {
 310                input_fd = 0;
 311                if (!pack_name) {
 312                        struct strbuf tmp_file = STRBUF_INIT;
 313                        output_fd = odb_mkstemp(&tmp_file,
 314                                                "pack/tmp_pack_XXXXXX");
 315                        pack_name = strbuf_detach(&tmp_file, NULL);
 316                } else {
 317                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 318                        if (output_fd < 0)
 319                                die_errno(_("unable to create '%s'"), pack_name);
 320                }
 321                nothread_data.pack_fd = output_fd;
 322        } else {
 323                input_fd = open(pack_name, O_RDONLY);
 324                if (input_fd < 0)
 325                        die_errno(_("cannot open packfile '%s'"), pack_name);
 326                output_fd = -1;
 327                nothread_data.pack_fd = input_fd;
 328        }
 329        the_hash_algo->init_fn(&input_ctx);
 330        return pack_name;
 331}
 332
 333static void parse_pack_header(void)
 334{
 335        struct pack_header *hdr = fill(sizeof(struct pack_header));
 336
 337        /* Header consistency check */
 338        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 339                die(_("pack signature mismatch"));
 340        if (!pack_version_ok(hdr->hdr_version))
 341                die(_("pack version %"PRIu32" unsupported"),
 342                        ntohl(hdr->hdr_version));
 343
 344        nr_objects = ntohl(hdr->hdr_entries);
 345        use(sizeof(struct pack_header));
 346}
 347
 348static NORETURN void bad_object(off_t offset, const char *format,
 349                       ...) __attribute__((format (printf, 2, 3)));
 350
 351static NORETURN void bad_object(off_t offset, const char *format, ...)
 352{
 353        va_list params;
 354        char buf[1024];
 355
 356        va_start(params, format);
 357        vsnprintf(buf, sizeof(buf), format, params);
 358        va_end(params);
 359        die(_("pack has bad object at offset %"PRIuMAX": %s"),
 360            (uintmax_t)offset, buf);
 361}
 362
 363static inline struct thread_local *get_thread_data(void)
 364{
 365#ifndef NO_PTHREADS
 366        if (threads_active)
 367                return pthread_getspecific(key);
 368        assert(!threads_active &&
 369               "This should only be reached when all threads are gone");
 370#endif
 371        return &nothread_data;
 372}
 373
 374#ifndef NO_PTHREADS
 375static void set_thread_data(struct thread_local *data)
 376{
 377        if (threads_active)
 378                pthread_setspecific(key, data);
 379}
 380#endif
 381
 382static struct base_data *alloc_base_data(void)
 383{
 384        struct base_data *base = xcalloc(1, sizeof(struct base_data));
 385        base->ref_last = -1;
 386        base->ofs_last = -1;
 387        return base;
 388}
 389
 390static void free_base_data(struct base_data *c)
 391{
 392        if (c->data) {
 393                FREE_AND_NULL(c->data);
 394                get_thread_data()->base_cache_used -= c->size;
 395        }
 396}
 397
 398static void prune_base_data(struct base_data *retain)
 399{
 400        struct base_data *b;
 401        struct thread_local *data = get_thread_data();
 402        for (b = data->base_cache;
 403             data->base_cache_used > delta_base_cache_limit && b;
 404             b = b->child) {
 405                if (b->data && b != retain)
 406                        free_base_data(b);
 407        }
 408}
 409
 410static void link_base_data(struct base_data *base, struct base_data *c)
 411{
 412        if (base)
 413                base->child = c;
 414        else
 415                get_thread_data()->base_cache = c;
 416
 417        c->base = base;
 418        c->child = NULL;
 419        if (c->data)
 420                get_thread_data()->base_cache_used += c->size;
 421        prune_base_data(c);
 422}
 423
 424static void unlink_base_data(struct base_data *c)
 425{
 426        struct base_data *base = c->base;
 427        if (base)
 428                base->child = NULL;
 429        else
 430                get_thread_data()->base_cache = NULL;
 431        free_base_data(c);
 432}
 433
 434static int is_delta_type(enum object_type type)
 435{
 436        return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 437}
 438
 439static void *unpack_entry_data(off_t offset, unsigned long size,
 440                               enum object_type type, struct object_id *oid)
 441{
 442        static char fixed_buf[8192];
 443        int status;
 444        git_zstream stream;
 445        void *buf;
 446        git_hash_ctx c;
 447        char hdr[32];
 448        int hdrlen;
 449
 450        if (!is_delta_type(type)) {
 451                hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(type), size) + 1;
 452                the_hash_algo->init_fn(&c);
 453                the_hash_algo->update_fn(&c, hdr, hdrlen);
 454        } else
 455                oid = NULL;
 456        if (type == OBJ_BLOB && size > big_file_threshold)
 457                buf = fixed_buf;
 458        else
 459                buf = xmallocz(size);
 460
 461        memset(&stream, 0, sizeof(stream));
 462        git_inflate_init(&stream);
 463        stream.next_out = buf;
 464        stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 465
 466        do {
 467                unsigned char *last_out = stream.next_out;
 468                stream.next_in = fill(1);
 469                stream.avail_in = input_len;
 470                status = git_inflate(&stream, 0);
 471                use(input_len - stream.avail_in);
 472                if (oid)
 473                        the_hash_algo->update_fn(&c, last_out, stream.next_out - last_out);
 474                if (buf == fixed_buf) {
 475                        stream.next_out = buf;
 476                        stream.avail_out = sizeof(fixed_buf);
 477                }
 478        } while (status == Z_OK);
 479        if (stream.total_out != size || status != Z_STREAM_END)
 480                bad_object(offset, _("inflate returned %d"), status);
 481        git_inflate_end(&stream);
 482        if (oid)
 483                the_hash_algo->final_fn(oid->hash, &c);
 484        return buf == fixed_buf ? NULL : buf;
 485}
 486
 487static void *unpack_raw_entry(struct object_entry *obj,
 488                              off_t *ofs_offset,
 489                              struct object_id *ref_oid,
 490                              struct object_id *oid)
 491{
 492        unsigned char *p;
 493        unsigned long size, c;
 494        off_t base_offset;
 495        unsigned shift;
 496        void *data;
 497
 498        obj->idx.offset = consumed_bytes;
 499        input_crc32 = crc32(0, NULL, 0);
 500
 501        p = fill(1);
 502        c = *p;
 503        use(1);
 504        obj->type = (c >> 4) & 7;
 505        size = (c & 15);
 506        shift = 4;
 507        while (c & 0x80) {
 508                p = fill(1);
 509                c = *p;
 510                use(1);
 511                size += (c & 0x7f) << shift;
 512                shift += 7;
 513        }
 514        obj->size = size;
 515
 516        switch (obj->type) {
 517        case OBJ_REF_DELTA:
 518                hashcpy(ref_oid->hash, fill(the_hash_algo->rawsz));
 519                use(the_hash_algo->rawsz);
 520                break;
 521        case OBJ_OFS_DELTA:
 522                p = fill(1);
 523                c = *p;
 524                use(1);
 525                base_offset = c & 127;
 526                while (c & 128) {
 527                        base_offset += 1;
 528                        if (!base_offset || MSB(base_offset, 7))
 529                                bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 530                        p = fill(1);
 531                        c = *p;
 532                        use(1);
 533                        base_offset = (base_offset << 7) + (c & 127);
 534                }
 535                *ofs_offset = obj->idx.offset - base_offset;
 536                if (*ofs_offset <= 0 || *ofs_offset >= obj->idx.offset)
 537                        bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 538                break;
 539        case OBJ_COMMIT:
 540        case OBJ_TREE:
 541        case OBJ_BLOB:
 542        case OBJ_TAG:
 543                break;
 544        default:
 545                bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 546        }
 547        obj->hdr_size = consumed_bytes - obj->idx.offset;
 548
 549        data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, oid);
 550        obj->idx.crc32 = input_crc32;
 551        return data;
 552}
 553
 554static void *unpack_data(struct object_entry *obj,
 555                         int (*consume)(const unsigned char *, unsigned long, void *),
 556                         void *cb_data)
 557{
 558        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 559        off_t len = obj[1].idx.offset - from;
 560        unsigned char *data, *inbuf;
 561        git_zstream stream;
 562        int status;
 563
 564        data = xmallocz(consume ? 64*1024 : obj->size);
 565        inbuf = xmalloc((len < 64*1024) ? (int)len : 64*1024);
 566
 567        memset(&stream, 0, sizeof(stream));
 568        git_inflate_init(&stream);
 569        stream.next_out = data;
 570        stream.avail_out = consume ? 64*1024 : obj->size;
 571
 572        do {
 573                ssize_t n = (len < 64*1024) ? (ssize_t)len : 64*1024;
 574                n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 575                if (n < 0)
 576                        die_errno(_("cannot pread pack file"));
 577                if (!n)
 578                        die(Q_("premature end of pack file, %"PRIuMAX" byte missing",
 579                               "premature end of pack file, %"PRIuMAX" bytes missing",
 580                               (unsigned int)len),
 581                            (uintmax_t)len);
 582                from += n;
 583                len -= n;
 584                stream.next_in = inbuf;
 585                stream.avail_in = n;
 586                if (!consume)
 587                        status = git_inflate(&stream, 0);
 588                else {
 589                        do {
 590                                status = git_inflate(&stream, 0);
 591                                if (consume(data, stream.next_out - data, cb_data)) {
 592                                        free(inbuf);
 593                                        free(data);
 594                                        return NULL;
 595                                }
 596                                stream.next_out = data;
 597                                stream.avail_out = 64*1024;
 598                        } while (status == Z_OK && stream.avail_in);
 599                }
 600        } while (len && status == Z_OK && !stream.avail_in);
 601
 602        /* This has been inflated OK when first encountered, so... */
 603        if (status != Z_STREAM_END || stream.total_out != obj->size)
 604                die(_("serious inflate inconsistency"));
 605
 606        git_inflate_end(&stream);
 607        free(inbuf);
 608        if (consume) {
 609                FREE_AND_NULL(data);
 610        }
 611        return data;
 612}
 613
 614static void *get_data_from_pack(struct object_entry *obj)
 615{
 616        return unpack_data(obj, NULL, NULL);
 617}
 618
 619static int compare_ofs_delta_bases(off_t offset1, off_t offset2,
 620                                   enum object_type type1,
 621                                   enum object_type type2)
 622{
 623        int cmp = type1 - type2;
 624        if (cmp)
 625                return cmp;
 626        return offset1 < offset2 ? -1 :
 627               offset1 > offset2 ?  1 :
 628               0;
 629}
 630
 631static int find_ofs_delta(const off_t offset, enum object_type type)
 632{
 633        int first = 0, last = nr_ofs_deltas;
 634
 635        while (first < last) {
 636                int next = first + (last - first) / 2;
 637                struct ofs_delta_entry *delta = &ofs_deltas[next];
 638                int cmp;
 639
 640                cmp = compare_ofs_delta_bases(offset, delta->offset,
 641                                              type, objects[delta->obj_no].type);
 642                if (!cmp)
 643                        return next;
 644                if (cmp < 0) {
 645                        last = next;
 646                        continue;
 647                }
 648                first = next+1;
 649        }
 650        return -first-1;
 651}
 652
 653static void find_ofs_delta_children(off_t offset,
 654                                    int *first_index, int *last_index,
 655                                    enum object_type type)
 656{
 657        int first = find_ofs_delta(offset, type);
 658        int last = first;
 659        int end = nr_ofs_deltas - 1;
 660
 661        if (first < 0) {
 662                *first_index = 0;
 663                *last_index = -1;
 664                return;
 665        }
 666        while (first > 0 && ofs_deltas[first - 1].offset == offset)
 667                --first;
 668        while (last < end && ofs_deltas[last + 1].offset == offset)
 669                ++last;
 670        *first_index = first;
 671        *last_index = last;
 672}
 673
 674static int compare_ref_delta_bases(const struct object_id *oid1,
 675                                   const struct object_id *oid2,
 676                                   enum object_type type1,
 677                                   enum object_type type2)
 678{
 679        int cmp = type1 - type2;
 680        if (cmp)
 681                return cmp;
 682        return oidcmp(oid1, oid2);
 683}
 684
 685static int find_ref_delta(const struct object_id *oid, enum object_type type)
 686{
 687        int first = 0, last = nr_ref_deltas;
 688
 689        while (first < last) {
 690                int next = first + (last - first) / 2;
 691                struct ref_delta_entry *delta = &ref_deltas[next];
 692                int cmp;
 693
 694                cmp = compare_ref_delta_bases(oid, &delta->oid,
 695                                              type, objects[delta->obj_no].type);
 696                if (!cmp)
 697                        return next;
 698                if (cmp < 0) {
 699                        last = next;
 700                        continue;
 701                }
 702                first = next+1;
 703        }
 704        return -first-1;
 705}
 706
 707static void find_ref_delta_children(const struct object_id *oid,
 708                                    int *first_index, int *last_index,
 709                                    enum object_type type)
 710{
 711        int first = find_ref_delta(oid, type);
 712        int last = first;
 713        int end = nr_ref_deltas - 1;
 714
 715        if (first < 0) {
 716                *first_index = 0;
 717                *last_index = -1;
 718                return;
 719        }
 720        while (first > 0 && !oidcmp(&ref_deltas[first - 1].oid, oid))
 721                --first;
 722        while (last < end && !oidcmp(&ref_deltas[last + 1].oid, oid))
 723                ++last;
 724        *first_index = first;
 725        *last_index = last;
 726}
 727
 728struct compare_data {
 729        struct object_entry *entry;
 730        struct git_istream *st;
 731        unsigned char *buf;
 732        unsigned long buf_size;
 733};
 734
 735static int compare_objects(const unsigned char *buf, unsigned long size,
 736                           void *cb_data)
 737{
 738        struct compare_data *data = cb_data;
 739
 740        if (data->buf_size < size) {
 741                free(data->buf);
 742                data->buf = xmalloc(size);
 743                data->buf_size = size;
 744        }
 745
 746        while (size) {
 747                ssize_t len = read_istream(data->st, data->buf, size);
 748                if (len == 0)
 749                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 750                            oid_to_hex(&data->entry->idx.oid));
 751                if (len < 0)
 752                        die(_("unable to read %s"),
 753                            oid_to_hex(&data->entry->idx.oid));
 754                if (memcmp(buf, data->buf, len))
 755                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 756                            oid_to_hex(&data->entry->idx.oid));
 757                size -= len;
 758                buf += len;
 759        }
 760        return 0;
 761}
 762
 763static int check_collison(struct object_entry *entry)
 764{
 765        struct compare_data data;
 766        enum object_type type;
 767        unsigned long size;
 768
 769        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 770                return -1;
 771
 772        memset(&data, 0, sizeof(data));
 773        data.entry = entry;
 774        data.st = open_istream(&entry->idx.oid, &type, &size, NULL);
 775        if (!data.st)
 776                return -1;
 777        if (size != entry->size || type != entry->type)
 778                die(_("SHA1 COLLISION FOUND WITH %s !"),
 779                    oid_to_hex(&entry->idx.oid));
 780        unpack_data(entry, compare_objects, &data);
 781        close_istream(data.st);
 782        free(data.buf);
 783        return 0;
 784}
 785
 786static void sha1_object(const void *data, struct object_entry *obj_entry,
 787                        unsigned long size, enum object_type type,
 788                        const struct object_id *oid)
 789{
 790        void *new_data = NULL;
 791        int collision_test_needed = 0;
 792
 793        assert(data || obj_entry);
 794
 795        if (startup_info->have_repository) {
 796                read_lock();
 797                collision_test_needed =
 798                        has_sha1_file_with_flags(oid->hash, OBJECT_INFO_QUICK);
 799                read_unlock();
 800        }
 801
 802        if (collision_test_needed && !data) {
 803                read_lock();
 804                if (!check_collison(obj_entry))
 805                        collision_test_needed = 0;
 806                read_unlock();
 807        }
 808        if (collision_test_needed) {
 809                void *has_data;
 810                enum object_type has_type;
 811                unsigned long has_size;
 812                read_lock();
 813                has_type = oid_object_info(oid, &has_size);
 814                if (has_type < 0)
 815                        die(_("cannot read existing object info %s"), oid_to_hex(oid));
 816                if (has_type != type || has_size != size)
 817                        die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 818                has_data = read_sha1_file(oid->hash, &has_type, &has_size);
 819                read_unlock();
 820                if (!data)
 821                        data = new_data = get_data_from_pack(obj_entry);
 822                if (!has_data)
 823                        die(_("cannot read existing object %s"), oid_to_hex(oid));
 824                if (size != has_size || type != has_type ||
 825                    memcmp(data, has_data, size) != 0)
 826                        die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 827                free(has_data);
 828        }
 829
 830        if (strict) {
 831                read_lock();
 832                if (type == OBJ_BLOB) {
 833                        struct blob *blob = lookup_blob(oid);
 834                        if (blob)
 835                                blob->object.flags |= FLAG_CHECKED;
 836                        else
 837                                die(_("invalid blob object %s"), oid_to_hex(oid));
 838                } else {
 839                        struct object *obj;
 840                        int eaten;
 841                        void *buf = (void *) data;
 842
 843                        assert(data && "data can only be NULL for large _blobs_");
 844
 845                        /*
 846                         * we do not need to free the memory here, as the
 847                         * buf is deleted by the caller.
 848                         */
 849                        obj = parse_object_buffer(oid, type, size, buf,
 850                                                  &eaten);
 851                        if (!obj)
 852                                die(_("invalid %s"), type_name(type));
 853                        if (do_fsck_object &&
 854                            fsck_object(obj, buf, size, &fsck_options))
 855                                die(_("Error in object"));
 856                        if (fsck_walk(obj, NULL, &fsck_options))
 857                                die(_("Not all child objects of %s are reachable"), oid_to_hex(&obj->oid));
 858
 859                        if (obj->type == OBJ_TREE) {
 860                                struct tree *item = (struct tree *) obj;
 861                                item->buffer = NULL;
 862                                obj->parsed = 0;
 863                        }
 864                        if (obj->type == OBJ_COMMIT) {
 865                                struct commit *commit = (struct commit *) obj;
 866                                if (detach_commit_buffer(commit, NULL) != data)
 867                                        die("BUG: parse_object_buffer transmogrified our buffer");
 868                        }
 869                        obj->flags |= FLAG_CHECKED;
 870                }
 871                read_unlock();
 872        }
 873
 874        free(new_data);
 875}
 876
 877/*
 878 * This function is part of find_unresolved_deltas(). There are two
 879 * walkers going in the opposite ways.
 880 *
 881 * The first one in find_unresolved_deltas() traverses down from
 882 * parent node to children, deflating nodes along the way. However,
 883 * memory for deflated nodes is limited by delta_base_cache_limit, so
 884 * at some point parent node's deflated content may be freed.
 885 *
 886 * The second walker is this function, which goes from current node up
 887 * to top parent if necessary to deflate the node. In normal
 888 * situation, its parent node would be already deflated, so it just
 889 * needs to apply delta.
 890 *
 891 * In the worst case scenario, parent node is no longer deflated because
 892 * we're running out of delta_base_cache_limit; we need to re-deflate
 893 * parents, possibly up to the top base.
 894 *
 895 * All deflated objects here are subject to be freed if we exceed
 896 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 897 * just need to make sure the last node is not freed.
 898 */
 899static void *get_base_data(struct base_data *c)
 900{
 901        if (!c->data) {
 902                struct object_entry *obj = c->obj;
 903                struct base_data **delta = NULL;
 904                int delta_nr = 0, delta_alloc = 0;
 905
 906                while (is_delta_type(c->obj->type) && !c->data) {
 907                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 908                        delta[delta_nr++] = c;
 909                        c = c->base;
 910                }
 911                if (!delta_nr) {
 912                        c->data = get_data_from_pack(obj);
 913                        c->size = obj->size;
 914                        get_thread_data()->base_cache_used += c->size;
 915                        prune_base_data(c);
 916                }
 917                for (; delta_nr > 0; delta_nr--) {
 918                        void *base, *raw;
 919                        c = delta[delta_nr - 1];
 920                        obj = c->obj;
 921                        base = get_base_data(c->base);
 922                        raw = get_data_from_pack(obj);
 923                        c->data = patch_delta(
 924                                base, c->base->size,
 925                                raw, obj->size,
 926                                &c->size);
 927                        free(raw);
 928                        if (!c->data)
 929                                bad_object(obj->idx.offset, _("failed to apply delta"));
 930                        get_thread_data()->base_cache_used += c->size;
 931                        prune_base_data(c);
 932                }
 933                free(delta);
 934        }
 935        return c->data;
 936}
 937
 938static void resolve_delta(struct object_entry *delta_obj,
 939                          struct base_data *base, struct base_data *result)
 940{
 941        void *base_data, *delta_data;
 942
 943        if (show_stat) {
 944                int i = delta_obj - objects;
 945                int j = base->obj - objects;
 946                obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 947                deepest_delta_lock();
 948                if (deepest_delta < obj_stat[i].delta_depth)
 949                        deepest_delta = obj_stat[i].delta_depth;
 950                deepest_delta_unlock();
 951                obj_stat[i].base_object_no = j;
 952        }
 953        delta_data = get_data_from_pack(delta_obj);
 954        base_data = get_base_data(base);
 955        result->obj = delta_obj;
 956        result->data = patch_delta(base_data, base->size,
 957                                   delta_data, delta_obj->size, &result->size);
 958        free(delta_data);
 959        if (!result->data)
 960                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 961        hash_object_file(result->data, result->size,
 962                         type_name(delta_obj->real_type), &delta_obj->idx.oid);
 963        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 964                    &delta_obj->idx.oid);
 965        counter_lock();
 966        nr_resolved_deltas++;
 967        counter_unlock();
 968}
 969
 970/*
 971 * Standard boolean compare-and-swap: atomically check whether "*type" is
 972 * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 973 * and return false.
 974 */
 975static int compare_and_swap_type(signed char *type,
 976                                 enum object_type want,
 977                                 enum object_type set)
 978{
 979        enum object_type old;
 980
 981        type_cas_lock();
 982        old = *type;
 983        if (old == want)
 984                *type = set;
 985        type_cas_unlock();
 986
 987        return old == want;
 988}
 989
 990static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 991                                                  struct base_data *prev_base)
 992{
 993        if (base->ref_last == -1 && base->ofs_last == -1) {
 994                find_ref_delta_children(&base->obj->idx.oid,
 995                                        &base->ref_first, &base->ref_last,
 996                                        OBJ_REF_DELTA);
 997
 998                find_ofs_delta_children(base->obj->idx.offset,
 999                                        &base->ofs_first, &base->ofs_last,
1000                                        OBJ_OFS_DELTA);
1001
1002                if (base->ref_last == -1 && base->ofs_last == -1) {
1003                        free(base->data);
1004                        return NULL;
1005                }
1006
1007                link_base_data(prev_base, base);
1008        }
1009
1010        if (base->ref_first <= base->ref_last) {
1011                struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
1012                struct base_data *result = alloc_base_data();
1013
1014                if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
1015                                           base->obj->real_type))
1016                        die("BUG: child->real_type != OBJ_REF_DELTA");
1017
1018                resolve_delta(child, base, result);
1019                if (base->ref_first == base->ref_last && base->ofs_last == -1)
1020                        free_base_data(base);
1021
1022                base->ref_first++;
1023                return result;
1024        }
1025
1026        if (base->ofs_first <= base->ofs_last) {
1027                struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
1028                struct base_data *result = alloc_base_data();
1029
1030                assert(child->real_type == OBJ_OFS_DELTA);
1031                child->real_type = base->obj->real_type;
1032                resolve_delta(child, base, result);
1033                if (base->ofs_first == base->ofs_last)
1034                        free_base_data(base);
1035
1036                base->ofs_first++;
1037                return result;
1038        }
1039
1040        unlink_base_data(base);
1041        return NULL;
1042}
1043
1044static void find_unresolved_deltas(struct base_data *base)
1045{
1046        struct base_data *new_base, *prev_base = NULL;
1047        for (;;) {
1048                new_base = find_unresolved_deltas_1(base, prev_base);
1049
1050                if (new_base) {
1051                        prev_base = base;
1052                        base = new_base;
1053                } else {
1054                        free(base);
1055                        base = prev_base;
1056                        if (!base)
1057                                return;
1058                        prev_base = base->base;
1059                }
1060        }
1061}
1062
1063static int compare_ofs_delta_entry(const void *a, const void *b)
1064{
1065        const struct ofs_delta_entry *delta_a = a;
1066        const struct ofs_delta_entry *delta_b = b;
1067
1068        return delta_a->offset < delta_b->offset ? -1 :
1069               delta_a->offset > delta_b->offset ?  1 :
1070               0;
1071}
1072
1073static int compare_ref_delta_entry(const void *a, const void *b)
1074{
1075        const struct ref_delta_entry *delta_a = a;
1076        const struct ref_delta_entry *delta_b = b;
1077
1078        return oidcmp(&delta_a->oid, &delta_b->oid);
1079}
1080
1081static void resolve_base(struct object_entry *obj)
1082{
1083        struct base_data *base_obj = alloc_base_data();
1084        base_obj->obj = obj;
1085        base_obj->data = NULL;
1086        find_unresolved_deltas(base_obj);
1087}
1088
1089#ifndef NO_PTHREADS
1090static void *threaded_second_pass(void *data)
1091{
1092        set_thread_data(data);
1093        for (;;) {
1094                int i;
1095                counter_lock();
1096                display_progress(progress, nr_resolved_deltas);
1097                counter_unlock();
1098                work_lock();
1099                while (nr_dispatched < nr_objects &&
1100                       is_delta_type(objects[nr_dispatched].type))
1101                        nr_dispatched++;
1102                if (nr_dispatched >= nr_objects) {
1103                        work_unlock();
1104                        break;
1105                }
1106                i = nr_dispatched++;
1107                work_unlock();
1108
1109                resolve_base(&objects[i]);
1110        }
1111        return NULL;
1112}
1113#endif
1114
1115/*
1116 * First pass:
1117 * - find locations of all objects;
1118 * - calculate SHA1 of all non-delta objects;
1119 * - remember base (SHA1 or offset) for all deltas.
1120 */
1121static void parse_pack_objects(unsigned char *hash)
1122{
1123        int i, nr_delays = 0;
1124        struct ofs_delta_entry *ofs_delta = ofs_deltas;
1125        struct object_id ref_delta_oid;
1126        struct stat st;
1127
1128        if (verbose)
1129                progress = start_progress(
1130                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1131                                nr_objects);
1132        for (i = 0; i < nr_objects; i++) {
1133                struct object_entry *obj = &objects[i];
1134                void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1135                                              &ref_delta_oid,
1136                                              &obj->idx.oid);
1137                obj->real_type = obj->type;
1138                if (obj->type == OBJ_OFS_DELTA) {
1139                        nr_ofs_deltas++;
1140                        ofs_delta->obj_no = i;
1141                        ofs_delta++;
1142                } else if (obj->type == OBJ_REF_DELTA) {
1143                        ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1144                        oidcpy(&ref_deltas[nr_ref_deltas].oid, &ref_delta_oid);
1145                        ref_deltas[nr_ref_deltas].obj_no = i;
1146                        nr_ref_deltas++;
1147                } else if (!data) {
1148                        /* large blobs, check later */
1149                        obj->real_type = OBJ_BAD;
1150                        nr_delays++;
1151                } else
1152                        sha1_object(data, NULL, obj->size, obj->type,
1153                                    &obj->idx.oid);
1154                free(data);
1155                display_progress(progress, i+1);
1156        }
1157        objects[i].idx.offset = consumed_bytes;
1158        stop_progress(&progress);
1159
1160        /* Check pack integrity */
1161        flush();
1162        the_hash_algo->final_fn(hash, &input_ctx);
1163        if (hashcmp(fill(the_hash_algo->rawsz), hash))
1164                die(_("pack is corrupted (SHA1 mismatch)"));
1165        use(the_hash_algo->rawsz);
1166
1167        /* If input_fd is a file, we should have reached its end now. */
1168        if (fstat(input_fd, &st))
1169                die_errno(_("cannot fstat packfile"));
1170        if (S_ISREG(st.st_mode) &&
1171                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1172                die(_("pack has junk at the end"));
1173
1174        for (i = 0; i < nr_objects; i++) {
1175                struct object_entry *obj = &objects[i];
1176                if (obj->real_type != OBJ_BAD)
1177                        continue;
1178                obj->real_type = obj->type;
1179                sha1_object(NULL, obj, obj->size, obj->type,
1180                            &obj->idx.oid);
1181                nr_delays--;
1182        }
1183        if (nr_delays)
1184                die(_("confusion beyond insanity in parse_pack_objects()"));
1185}
1186
1187/*
1188 * Second pass:
1189 * - for all non-delta objects, look if it is used as a base for
1190 *   deltas;
1191 * - if used as a base, uncompress the object and apply all deltas,
1192 *   recursively checking if the resulting object is used as a base
1193 *   for some more deltas.
1194 */
1195static void resolve_deltas(void)
1196{
1197        int i;
1198
1199        if (!nr_ofs_deltas && !nr_ref_deltas)
1200                return;
1201
1202        /* Sort deltas by base SHA1/offset for fast searching */
1203        QSORT(ofs_deltas, nr_ofs_deltas, compare_ofs_delta_entry);
1204        QSORT(ref_deltas, nr_ref_deltas, compare_ref_delta_entry);
1205
1206        if (verbose || show_resolving_progress)
1207                progress = start_progress(_("Resolving deltas"),
1208                                          nr_ref_deltas + nr_ofs_deltas);
1209
1210#ifndef NO_PTHREADS
1211        nr_dispatched = 0;
1212        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1213                init_thread();
1214                for (i = 0; i < nr_threads; i++) {
1215                        int ret = pthread_create(&thread_data[i].thread, NULL,
1216                                                 threaded_second_pass, thread_data + i);
1217                        if (ret)
1218                                die(_("unable to create thread: %s"),
1219                                    strerror(ret));
1220                }
1221                for (i = 0; i < nr_threads; i++)
1222                        pthread_join(thread_data[i].thread, NULL);
1223                cleanup_thread();
1224                return;
1225        }
1226#endif
1227
1228        for (i = 0; i < nr_objects; i++) {
1229                struct object_entry *obj = &objects[i];
1230
1231                if (is_delta_type(obj->type))
1232                        continue;
1233                resolve_base(obj);
1234                display_progress(progress, nr_resolved_deltas);
1235        }
1236}
1237
1238/*
1239 * Third pass:
1240 * - append objects to convert thin pack to full pack if required
1241 * - write the final pack hash
1242 */
1243static void fix_unresolved_deltas(struct hashfile *f);
1244static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_hash)
1245{
1246        if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1247                stop_progress(&progress);
1248                /* Flush remaining pack final hash. */
1249                flush();
1250                return;
1251        }
1252
1253        if (fix_thin_pack) {
1254                struct hashfile *f;
1255                unsigned char read_hash[GIT_MAX_RAWSZ], tail_hash[GIT_MAX_RAWSZ];
1256                struct strbuf msg = STRBUF_INIT;
1257                int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1258                int nr_objects_initial = nr_objects;
1259                if (nr_unresolved <= 0)
1260                        die(_("confusion beyond insanity"));
1261                REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1262                memset(objects + nr_objects + 1, 0,
1263                       nr_unresolved * sizeof(*objects));
1264                f = hashfd(output_fd, curr_pack);
1265                fix_unresolved_deltas(f);
1266                strbuf_addf(&msg, Q_("completed with %d local object",
1267                                     "completed with %d local objects",
1268                                     nr_objects - nr_objects_initial),
1269                            nr_objects - nr_objects_initial);
1270                stop_progress_msg(&progress, msg.buf);
1271                strbuf_release(&msg);
1272                hashclose(f, tail_hash, 0);
1273                hashcpy(read_hash, pack_hash);
1274                fixup_pack_header_footer(output_fd, pack_hash,
1275                                         curr_pack, nr_objects,
1276                                         read_hash, consumed_bytes-the_hash_algo->rawsz);
1277                if (hashcmp(read_hash, tail_hash) != 0)
1278                        die(_("Unexpected tail checksum for %s "
1279                              "(disk corruption?)"), curr_pack);
1280        }
1281        if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1282                die(Q_("pack has %d unresolved delta",
1283                       "pack has %d unresolved deltas",
1284                       nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1285                    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1286}
1287
1288static int write_compressed(struct hashfile *f, void *in, unsigned int size)
1289{
1290        git_zstream stream;
1291        int status;
1292        unsigned char outbuf[4096];
1293
1294        git_deflate_init(&stream, zlib_compression_level);
1295        stream.next_in = in;
1296        stream.avail_in = size;
1297
1298        do {
1299                stream.next_out = outbuf;
1300                stream.avail_out = sizeof(outbuf);
1301                status = git_deflate(&stream, Z_FINISH);
1302                hashwrite(f, outbuf, sizeof(outbuf) - stream.avail_out);
1303        } while (status == Z_OK);
1304
1305        if (status != Z_STREAM_END)
1306                die(_("unable to deflate appended object (%d)"), status);
1307        size = stream.total_out;
1308        git_deflate_end(&stream);
1309        return size;
1310}
1311
1312static struct object_entry *append_obj_to_pack(struct hashfile *f,
1313                               const unsigned char *sha1, void *buf,
1314                               unsigned long size, enum object_type type)
1315{
1316        struct object_entry *obj = &objects[nr_objects++];
1317        unsigned char header[10];
1318        unsigned long s = size;
1319        int n = 0;
1320        unsigned char c = (type << 4) | (s & 15);
1321        s >>= 4;
1322        while (s) {
1323                header[n++] = c | 0x80;
1324                c = s & 0x7f;
1325                s >>= 7;
1326        }
1327        header[n++] = c;
1328        crc32_begin(f);
1329        hashwrite(f, header, n);
1330        obj[0].size = size;
1331        obj[0].hdr_size = n;
1332        obj[0].type = type;
1333        obj[0].real_type = type;
1334        obj[1].idx.offset = obj[0].idx.offset + n;
1335        obj[1].idx.offset += write_compressed(f, buf, size);
1336        obj[0].idx.crc32 = crc32_end(f);
1337        hashflush(f);
1338        hashcpy(obj->idx.oid.hash, sha1);
1339        return obj;
1340}
1341
1342static int delta_pos_compare(const void *_a, const void *_b)
1343{
1344        struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1345        struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1346        return a->obj_no - b->obj_no;
1347}
1348
1349static void fix_unresolved_deltas(struct hashfile *f)
1350{
1351        struct ref_delta_entry **sorted_by_pos;
1352        int i;
1353
1354        /*
1355         * Since many unresolved deltas may well be themselves base objects
1356         * for more unresolved deltas, we really want to include the
1357         * smallest number of base objects that would cover as much delta
1358         * as possible by picking the
1359         * trunc deltas first, allowing for other deltas to resolve without
1360         * additional base objects.  Since most base objects are to be found
1361         * before deltas depending on them, a good heuristic is to start
1362         * resolving deltas in the same order as their position in the pack.
1363         */
1364        ALLOC_ARRAY(sorted_by_pos, nr_ref_deltas);
1365        for (i = 0; i < nr_ref_deltas; i++)
1366                sorted_by_pos[i] = &ref_deltas[i];
1367        QSORT(sorted_by_pos, nr_ref_deltas, delta_pos_compare);
1368
1369        for (i = 0; i < nr_ref_deltas; i++) {
1370                struct ref_delta_entry *d = sorted_by_pos[i];
1371                enum object_type type;
1372                struct base_data *base_obj = alloc_base_data();
1373
1374                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1375                        continue;
1376                base_obj->data = read_sha1_file(d->oid.hash, &type, &base_obj->size);
1377                if (!base_obj->data)
1378                        continue;
1379
1380                if (check_object_signature(&d->oid, base_obj->data,
1381                                base_obj->size, type_name(type)))
1382                        die(_("local object %s is corrupt"), oid_to_hex(&d->oid));
1383                base_obj->obj = append_obj_to_pack(f, d->oid.hash,
1384                                        base_obj->data, base_obj->size, type);
1385                find_unresolved_deltas(base_obj);
1386                display_progress(progress, nr_resolved_deltas);
1387        }
1388        free(sorted_by_pos);
1389}
1390
1391static const char *derive_filename(const char *pack_name, const char *suffix,
1392                                   struct strbuf *buf)
1393{
1394        size_t len;
1395        if (!strip_suffix(pack_name, ".pack", &len))
1396                die(_("packfile name '%s' does not end with '.pack'"),
1397                    pack_name);
1398        strbuf_add(buf, pack_name, len);
1399        strbuf_addch(buf, '.');
1400        strbuf_addstr(buf, suffix);
1401        return buf->buf;
1402}
1403
1404static void write_special_file(const char *suffix, const char *msg,
1405                               const char *pack_name, const unsigned char *hash,
1406                               const char **report)
1407{
1408        struct strbuf name_buf = STRBUF_INIT;
1409        const char *filename;
1410        int fd;
1411        int msg_len = strlen(msg);
1412
1413        if (pack_name)
1414                filename = derive_filename(pack_name, suffix, &name_buf);
1415        else
1416                filename = odb_pack_name(&name_buf, hash, suffix);
1417
1418        fd = odb_pack_keep(filename);
1419        if (fd < 0) {
1420                if (errno != EEXIST)
1421                        die_errno(_("cannot write %s file '%s'"),
1422                                  suffix, filename);
1423        } else {
1424                if (msg_len > 0) {
1425                        write_or_die(fd, msg, msg_len);
1426                        write_or_die(fd, "\n", 1);
1427                }
1428                if (close(fd) != 0)
1429                        die_errno(_("cannot close written %s file '%s'"),
1430                                  suffix, filename);
1431                if (report)
1432                        *report = suffix;
1433        }
1434        strbuf_release(&name_buf);
1435}
1436
1437static void final(const char *final_pack_name, const char *curr_pack_name,
1438                  const char *final_index_name, const char *curr_index_name,
1439                  const char *keep_msg, const char *promisor_msg,
1440                  unsigned char *hash)
1441{
1442        const char *report = "pack";
1443        struct strbuf pack_name = STRBUF_INIT;
1444        struct strbuf index_name = STRBUF_INIT;
1445        int err;
1446
1447        if (!from_stdin) {
1448                close(input_fd);
1449        } else {
1450                fsync_or_die(output_fd, curr_pack_name);
1451                err = close(output_fd);
1452                if (err)
1453                        die_errno(_("error while closing pack file"));
1454        }
1455
1456        if (keep_msg)
1457                write_special_file("keep", keep_msg, final_pack_name, hash,
1458                                   &report);
1459        if (promisor_msg)
1460                write_special_file("promisor", promisor_msg, final_pack_name,
1461                                   hash, NULL);
1462
1463        if (final_pack_name != curr_pack_name) {
1464                if (!final_pack_name)
1465                        final_pack_name = odb_pack_name(&pack_name, hash, "pack");
1466                if (finalize_object_file(curr_pack_name, final_pack_name))
1467                        die(_("cannot store pack file"));
1468        } else if (from_stdin)
1469                chmod(final_pack_name, 0444);
1470
1471        if (final_index_name != curr_index_name) {
1472                if (!final_index_name)
1473                        final_index_name = odb_pack_name(&index_name, hash, "idx");
1474                if (finalize_object_file(curr_index_name, final_index_name))
1475                        die(_("cannot store index file"));
1476        } else
1477                chmod(final_index_name, 0444);
1478
1479        if (!from_stdin) {
1480                printf("%s\n", sha1_to_hex(hash));
1481        } else {
1482                struct strbuf buf = STRBUF_INIT;
1483
1484                strbuf_addf(&buf, "%s\t%s\n", report, sha1_to_hex(hash));
1485                write_or_die(1, buf.buf, buf.len);
1486                strbuf_release(&buf);
1487
1488                /*
1489                 * Let's just mimic git-unpack-objects here and write
1490                 * the last part of the input buffer to stdout.
1491                 */
1492                while (input_len) {
1493                        err = xwrite(1, input_buffer + input_offset, input_len);
1494                        if (err <= 0)
1495                                break;
1496                        input_len -= err;
1497                        input_offset += err;
1498                }
1499        }
1500
1501        strbuf_release(&index_name);
1502        strbuf_release(&pack_name);
1503}
1504
1505static int git_index_pack_config(const char *k, const char *v, void *cb)
1506{
1507        struct pack_idx_option *opts = cb;
1508
1509        if (!strcmp(k, "pack.indexversion")) {
1510                opts->version = git_config_int(k, v);
1511                if (opts->version > 2)
1512                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1513                return 0;
1514        }
1515        if (!strcmp(k, "pack.threads")) {
1516                nr_threads = git_config_int(k, v);
1517                if (nr_threads < 0)
1518                        die(_("invalid number of threads specified (%d)"),
1519                            nr_threads);
1520#ifdef NO_PTHREADS
1521                if (nr_threads != 1)
1522                        warning(_("no threads support, ignoring %s"), k);
1523                nr_threads = 1;
1524#endif
1525                return 0;
1526        }
1527        return git_default_config(k, v, cb);
1528}
1529
1530static int cmp_uint32(const void *a_, const void *b_)
1531{
1532        uint32_t a = *((uint32_t *)a_);
1533        uint32_t b = *((uint32_t *)b_);
1534
1535        return (a < b) ? -1 : (a != b);
1536}
1537
1538static void read_v2_anomalous_offsets(struct packed_git *p,
1539                                      struct pack_idx_option *opts)
1540{
1541        const uint32_t *idx1, *idx2;
1542        uint32_t i;
1543
1544        /* The address of the 4-byte offset table */
1545        idx1 = (((const uint32_t *)p->index_data)
1546                + 2 /* 8-byte header */
1547                + 256 /* fan out */
1548                + 5 * p->num_objects /* 20-byte SHA-1 table */
1549                + p->num_objects /* CRC32 table */
1550                );
1551
1552        /* The address of the 8-byte offset table */
1553        idx2 = idx1 + p->num_objects;
1554
1555        for (i = 0; i < p->num_objects; i++) {
1556                uint32_t off = ntohl(idx1[i]);
1557                if (!(off & 0x80000000))
1558                        continue;
1559                off = off & 0x7fffffff;
1560                check_pack_index_ptr(p, &idx2[off * 2]);
1561                if (idx2[off * 2])
1562                        continue;
1563                /*
1564                 * The real offset is ntohl(idx2[off * 2]) in high 4
1565                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1566                 * octets.  But idx2[off * 2] is Zero!!!
1567                 */
1568                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1569                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1570        }
1571
1572        QSORT(opts->anomaly, opts->anomaly_nr, cmp_uint32);
1573}
1574
1575static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1576{
1577        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1578
1579        if (!p)
1580                die(_("Cannot open existing pack file '%s'"), pack_name);
1581        if (open_pack_index(p))
1582                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1583
1584        /* Read the attributes from the existing idx file */
1585        opts->version = p->index_version;
1586
1587        if (opts->version == 2)
1588                read_v2_anomalous_offsets(p, opts);
1589
1590        /*
1591         * Get rid of the idx file as we do not need it anymore.
1592         * NEEDSWORK: extract this bit from free_pack_by_name() in
1593         * sha1_file.c, perhaps?  It shouldn't matter very much as we
1594         * know we haven't installed this pack (hence we never have
1595         * read anything from it).
1596         */
1597        close_pack_index(p);
1598        free(p);
1599}
1600
1601static void show_pack_info(int stat_only)
1602{
1603        int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1604        unsigned long *chain_histogram = NULL;
1605
1606        if (deepest_delta)
1607                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1608
1609        for (i = 0; i < nr_objects; i++) {
1610                struct object_entry *obj = &objects[i];
1611
1612                if (is_delta_type(obj->type))
1613                        chain_histogram[obj_stat[i].delta_depth - 1]++;
1614                if (stat_only)
1615                        continue;
1616                printf("%s %-6s %lu %lu %"PRIuMAX,
1617                       oid_to_hex(&obj->idx.oid),
1618                       type_name(obj->real_type), obj->size,
1619                       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1620                       (uintmax_t)obj->idx.offset);
1621                if (is_delta_type(obj->type)) {
1622                        struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1623                        printf(" %u %s", obj_stat[i].delta_depth,
1624                               oid_to_hex(&bobj->idx.oid));
1625                }
1626                putchar('\n');
1627        }
1628
1629        if (baseobjects)
1630                printf_ln(Q_("non delta: %d object",
1631                             "non delta: %d objects",
1632                             baseobjects),
1633                          baseobjects);
1634        for (i = 0; i < deepest_delta; i++) {
1635                if (!chain_histogram[i])
1636                        continue;
1637                printf_ln(Q_("chain length = %d: %lu object",
1638                             "chain length = %d: %lu objects",
1639                             chain_histogram[i]),
1640                          i + 1,
1641                          chain_histogram[i]);
1642        }
1643}
1644
1645int cmd_index_pack(int argc, const char **argv, const char *prefix)
1646{
1647        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1648        const char *curr_index;
1649        const char *index_name = NULL, *pack_name = NULL;
1650        const char *keep_msg = NULL;
1651        const char *promisor_msg = NULL;
1652        struct strbuf index_name_buf = STRBUF_INIT;
1653        struct pack_idx_entry **idx_objects;
1654        struct pack_idx_option opts;
1655        unsigned char pack_hash[GIT_MAX_RAWSZ];
1656        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1657        int report_end_of_input = 0;
1658
1659        /*
1660         * index-pack never needs to fetch missing objects, since it only
1661         * accesses the repo to do hash collision checks
1662         */
1663        fetch_if_missing = 0;
1664
1665        if (argc == 2 && !strcmp(argv[1], "-h"))
1666                usage(index_pack_usage);
1667
1668        check_replace_refs = 0;
1669        fsck_options.walk = mark_link;
1670
1671        reset_pack_idx_option(&opts);
1672        git_config(git_index_pack_config, &opts);
1673        if (prefix && chdir(prefix))
1674                die(_("Cannot come back to cwd"));
1675
1676        for (i = 1; i < argc; i++) {
1677                const char *arg = argv[i];
1678
1679                if (*arg == '-') {
1680                        if (!strcmp(arg, "--stdin")) {
1681                                from_stdin = 1;
1682                        } else if (!strcmp(arg, "--fix-thin")) {
1683                                fix_thin_pack = 1;
1684                        } else if (skip_to_optional_arg(arg, "--strict", &arg)) {
1685                                strict = 1;
1686                                do_fsck_object = 1;
1687                                fsck_set_msg_types(&fsck_options, arg);
1688                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1689                                strict = 1;
1690                                check_self_contained_and_connected = 1;
1691                        } else if (!strcmp(arg, "--verify")) {
1692                                verify = 1;
1693                        } else if (!strcmp(arg, "--verify-stat")) {
1694                                verify = 1;
1695                                show_stat = 1;
1696                        } else if (!strcmp(arg, "--verify-stat-only")) {
1697                                verify = 1;
1698                                show_stat = 1;
1699                                stat_only = 1;
1700                        } else if (skip_to_optional_arg(arg, "--keep", &keep_msg)) {
1701                                ; /* nothing to do */
1702                        } else if (skip_to_optional_arg(arg, "--promisor", &promisor_msg)) {
1703                                ; /* already parsed */
1704                        } else if (starts_with(arg, "--threads=")) {
1705                                char *end;
1706                                nr_threads = strtoul(arg+10, &end, 0);
1707                                if (!arg[10] || *end || nr_threads < 0)
1708                                        usage(index_pack_usage);
1709#ifdef NO_PTHREADS
1710                                if (nr_threads != 1)
1711                                        warning(_("no threads support, "
1712                                                  "ignoring %s"), arg);
1713                                nr_threads = 1;
1714#endif
1715                        } else if (starts_with(arg, "--pack_header=")) {
1716                                struct pack_header *hdr;
1717                                char *c;
1718
1719                                hdr = (struct pack_header *)input_buffer;
1720                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1721                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1722                                if (*c != ',')
1723                                        die(_("bad %s"), arg);
1724                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1725                                if (*c)
1726                                        die(_("bad %s"), arg);
1727                                input_len = sizeof(*hdr);
1728                        } else if (!strcmp(arg, "-v")) {
1729                                verbose = 1;
1730                        } else if (!strcmp(arg, "--show-resolving-progress")) {
1731                                show_resolving_progress = 1;
1732                        } else if (!strcmp(arg, "--report-end-of-input")) {
1733                                report_end_of_input = 1;
1734                        } else if (!strcmp(arg, "-o")) {
1735                                if (index_name || (i+1) >= argc)
1736                                        usage(index_pack_usage);
1737                                index_name = argv[++i];
1738                        } else if (starts_with(arg, "--index-version=")) {
1739                                char *c;
1740                                opts.version = strtoul(arg + 16, &c, 10);
1741                                if (opts.version > 2)
1742                                        die(_("bad %s"), arg);
1743                                if (*c == ',')
1744                                        opts.off32_limit = strtoul(c+1, &c, 0);
1745                                if (*c || opts.off32_limit & 0x80000000)
1746                                        die(_("bad %s"), arg);
1747                        } else if (skip_prefix(arg, "--max-input-size=", &arg)) {
1748                                max_input_size = strtoumax(arg, NULL, 10);
1749                        } else
1750                                usage(index_pack_usage);
1751                        continue;
1752                }
1753
1754                if (pack_name)
1755                        usage(index_pack_usage);
1756                pack_name = arg;
1757        }
1758
1759        if (!pack_name && !from_stdin)
1760                usage(index_pack_usage);
1761        if (fix_thin_pack && !from_stdin)
1762                die(_("--fix-thin cannot be used without --stdin"));
1763        if (from_stdin && !startup_info->have_repository)
1764                die(_("--stdin requires a git repository"));
1765        if (!index_name && pack_name)
1766                index_name = derive_filename(pack_name, "idx", &index_name_buf);
1767
1768        if (verify) {
1769                if (!index_name)
1770                        die(_("--verify with no packfile name given"));
1771                read_idx_option(&opts, index_name);
1772                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1773        }
1774        if (strict)
1775                opts.flags |= WRITE_IDX_STRICT;
1776
1777#ifndef NO_PTHREADS
1778        if (!nr_threads) {
1779                nr_threads = online_cpus();
1780                /* An experiment showed that more threads does not mean faster */
1781                if (nr_threads > 3)
1782                        nr_threads = 3;
1783        }
1784#endif
1785
1786        curr_pack = open_pack_file(pack_name);
1787        parse_pack_header();
1788        objects = xcalloc(st_add(nr_objects, 1), sizeof(struct object_entry));
1789        if (show_stat)
1790                obj_stat = xcalloc(st_add(nr_objects, 1), sizeof(struct object_stat));
1791        ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
1792        parse_pack_objects(pack_hash);
1793        if (report_end_of_input)
1794                write_in_full(2, "\0", 1);
1795        resolve_deltas();
1796        conclude_pack(fix_thin_pack, curr_pack, pack_hash);
1797        free(ofs_deltas);
1798        free(ref_deltas);
1799        if (strict)
1800                foreign_nr = check_objects();
1801
1802        if (show_stat)
1803                show_pack_info(stat_only);
1804
1805        ALLOC_ARRAY(idx_objects, nr_objects);
1806        for (i = 0; i < nr_objects; i++)
1807                idx_objects[i] = &objects[i].idx;
1808        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_hash);
1809        free(idx_objects);
1810
1811        if (!verify)
1812                final(pack_name, curr_pack,
1813                      index_name, curr_index,
1814                      keep_msg, promisor_msg,
1815                      pack_hash);
1816        else
1817                close(input_fd);
1818        free(objects);
1819        strbuf_release(&index_name_buf);
1820        if (pack_name == NULL)
1821                free((void *) curr_pack);
1822        if (index_name == NULL)
1823                free((void *) curr_index);
1824
1825        /*
1826         * Let the caller know this pack is not self contained
1827         */
1828        if (check_self_contained_and_connected && foreign_nr)
1829                return 1;
1830
1831        return 0;
1832}