builtin / index-pack.con commit worktree: fix worktree add race (7af01f2)
   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#include "object-store.h"
  17
  18static const char index_pack_usage[] =
  19"git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
  20
  21struct object_entry {
  22        struct pack_idx_entry idx;
  23        unsigned long size;
  24        unsigned char hdr_size;
  25        signed char type;
  26        signed char real_type;
  27};
  28
  29struct object_stat {
  30        unsigned delta_depth;
  31        int base_object_no;
  32};
  33
  34struct base_data {
  35        struct base_data *base;
  36        struct base_data *child;
  37        struct object_entry *obj;
  38        void *data;
  39        unsigned long size;
  40        int ref_first, ref_last;
  41        int ofs_first, ofs_last;
  42};
  43
  44struct thread_local {
  45        pthread_t thread;
  46        struct base_data *base_cache;
  47        size_t base_cache_used;
  48        int pack_fd;
  49};
  50
  51/* Remember to update object flag allocation in object.h */
  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
  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
 178static int mark_link(struct object *obj, int type, void *data, struct fsck_options *options)
 179{
 180        if (!obj)
 181                return -1;
 182
 183        if (type != OBJ_ANY && obj->type != type)
 184                die(_("object type mismatch at %s"), oid_to_hex(&obj->oid));
 185
 186        obj->flags |= FLAG_LINK;
 187        return 0;
 188}
 189
 190/* The content of each linked object must have been checked
 191   or it must be already present in the object database */
 192static unsigned check_object(struct object *obj)
 193{
 194        if (!obj)
 195                return 0;
 196
 197        if (!(obj->flags & FLAG_LINK))
 198                return 0;
 199
 200        if (!(obj->flags & FLAG_CHECKED)) {
 201                unsigned long size;
 202                int type = oid_object_info(the_repository, &obj->oid, &size);
 203                if (type <= 0)
 204                        die(_("did not receive expected object %s"),
 205                              oid_to_hex(&obj->oid));
 206                if (type != obj->type)
 207                        die(_("object %s: expected type %s, found %s"),
 208                            oid_to_hex(&obj->oid),
 209                            type_name(obj->type), type_name(type));
 210                obj->flags |= FLAG_CHECKED;
 211                return 1;
 212        }
 213
 214        return 0;
 215}
 216
 217static unsigned check_objects(void)
 218{
 219        unsigned i, max, foreign_nr = 0;
 220
 221        max = get_max_object_index();
 222        for (i = 0; i < max; i++)
 223                foreign_nr += check_object(get_indexed_object(i));
 224        return foreign_nr;
 225}
 226
 227
 228/* Discard current buffer used content. */
 229static void flush(void)
 230{
 231        if (input_offset) {
 232                if (output_fd >= 0)
 233                        write_or_die(output_fd, input_buffer, input_offset);
 234                the_hash_algo->update_fn(&input_ctx, input_buffer, input_offset);
 235                memmove(input_buffer, input_buffer + input_offset, input_len);
 236                input_offset = 0;
 237        }
 238}
 239
 240/*
 241 * Make sure at least "min" bytes are available in the buffer, and
 242 * return the pointer to the buffer.
 243 */
 244static void *fill(int min)
 245{
 246        if (min <= input_len)
 247                return input_buffer + input_offset;
 248        if (min > sizeof(input_buffer))
 249                die(Q_("cannot fill %d byte",
 250                       "cannot fill %d bytes",
 251                       min),
 252                    min);
 253        flush();
 254        do {
 255                ssize_t ret = xread(input_fd, input_buffer + input_len,
 256                                sizeof(input_buffer) - input_len);
 257                if (ret <= 0) {
 258                        if (!ret)
 259                                die(_("early EOF"));
 260                        die_errno(_("read error on input"));
 261                }
 262                input_len += ret;
 263                if (from_stdin)
 264                        display_throughput(progress, consumed_bytes + input_len);
 265        } while (input_len < min);
 266        return input_buffer;
 267}
 268
 269static void use(int bytes)
 270{
 271        if (bytes > input_len)
 272                die(_("used more bytes than were available"));
 273        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 274        input_len -= bytes;
 275        input_offset += bytes;
 276
 277        /* make sure off_t is sufficiently large not to wrap */
 278        if (signed_add_overflows(consumed_bytes, bytes))
 279                die(_("pack too large for current definition of off_t"));
 280        consumed_bytes += bytes;
 281        if (max_input_size && consumed_bytes > max_input_size)
 282                die(_("pack exceeds maximum allowed size"));
 283}
 284
 285static const char *open_pack_file(const char *pack_name)
 286{
 287        if (from_stdin) {
 288                input_fd = 0;
 289                if (!pack_name) {
 290                        struct strbuf tmp_file = STRBUF_INIT;
 291                        output_fd = odb_mkstemp(&tmp_file,
 292                                                "pack/tmp_pack_XXXXXX");
 293                        pack_name = strbuf_detach(&tmp_file, NULL);
 294                } else {
 295                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 296                        if (output_fd < 0)
 297                                die_errno(_("unable to create '%s'"), pack_name);
 298                }
 299                nothread_data.pack_fd = output_fd;
 300        } else {
 301                input_fd = open(pack_name, O_RDONLY);
 302                if (input_fd < 0)
 303                        die_errno(_("cannot open packfile '%s'"), pack_name);
 304                output_fd = -1;
 305                nothread_data.pack_fd = input_fd;
 306        }
 307        the_hash_algo->init_fn(&input_ctx);
 308        return pack_name;
 309}
 310
 311static void parse_pack_header(void)
 312{
 313        struct pack_header *hdr = fill(sizeof(struct pack_header));
 314
 315        /* Header consistency check */
 316        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 317                die(_("pack signature mismatch"));
 318        if (!pack_version_ok(hdr->hdr_version))
 319                die(_("pack version %"PRIu32" unsupported"),
 320                        ntohl(hdr->hdr_version));
 321
 322        nr_objects = ntohl(hdr->hdr_entries);
 323        use(sizeof(struct pack_header));
 324}
 325
 326static NORETURN void bad_object(off_t offset, const char *format,
 327                       ...) __attribute__((format (printf, 2, 3)));
 328
 329static NORETURN void bad_object(off_t offset, const char *format, ...)
 330{
 331        va_list params;
 332        char buf[1024];
 333
 334        va_start(params, format);
 335        vsnprintf(buf, sizeof(buf), format, params);
 336        va_end(params);
 337        die(_("pack has bad object at offset %"PRIuMAX": %s"),
 338            (uintmax_t)offset, buf);
 339}
 340
 341static inline struct thread_local *get_thread_data(void)
 342{
 343        if (HAVE_THREADS) {
 344                if (threads_active)
 345                        return pthread_getspecific(key);
 346                assert(!threads_active &&
 347                       "This should only be reached when all threads are gone");
 348        }
 349        return &nothread_data;
 350}
 351
 352static void set_thread_data(struct thread_local *data)
 353{
 354        if (threads_active)
 355                pthread_setspecific(key, data);
 356}
 357
 358static struct base_data *alloc_base_data(void)
 359{
 360        struct base_data *base = xcalloc(1, sizeof(struct base_data));
 361        base->ref_last = -1;
 362        base->ofs_last = -1;
 363        return base;
 364}
 365
 366static void free_base_data(struct base_data *c)
 367{
 368        if (c->data) {
 369                FREE_AND_NULL(c->data);
 370                get_thread_data()->base_cache_used -= c->size;
 371        }
 372}
 373
 374static void prune_base_data(struct base_data *retain)
 375{
 376        struct base_data *b;
 377        struct thread_local *data = get_thread_data();
 378        for (b = data->base_cache;
 379             data->base_cache_used > delta_base_cache_limit && b;
 380             b = b->child) {
 381                if (b->data && b != retain)
 382                        free_base_data(b);
 383        }
 384}
 385
 386static void link_base_data(struct base_data *base, struct base_data *c)
 387{
 388        if (base)
 389                base->child = c;
 390        else
 391                get_thread_data()->base_cache = c;
 392
 393        c->base = base;
 394        c->child = NULL;
 395        if (c->data)
 396                get_thread_data()->base_cache_used += c->size;
 397        prune_base_data(c);
 398}
 399
 400static void unlink_base_data(struct base_data *c)
 401{
 402        struct base_data *base = c->base;
 403        if (base)
 404                base->child = NULL;
 405        else
 406                get_thread_data()->base_cache = NULL;
 407        free_base_data(c);
 408}
 409
 410static int is_delta_type(enum object_type type)
 411{
 412        return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 413}
 414
 415static void *unpack_entry_data(off_t offset, unsigned long size,
 416                               enum object_type type, struct object_id *oid)
 417{
 418        static char fixed_buf[8192];
 419        int status;
 420        git_zstream stream;
 421        void *buf;
 422        git_hash_ctx c;
 423        char hdr[32];
 424        int hdrlen;
 425
 426        if (!is_delta_type(type)) {
 427                hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX,
 428                                   type_name(type),(uintmax_t)size) + 1;
 429                the_hash_algo->init_fn(&c);
 430                the_hash_algo->update_fn(&c, hdr, hdrlen);
 431        } else
 432                oid = NULL;
 433        if (type == OBJ_BLOB && size > big_file_threshold)
 434                buf = fixed_buf;
 435        else
 436                buf = xmallocz(size);
 437
 438        memset(&stream, 0, sizeof(stream));
 439        git_inflate_init(&stream);
 440        stream.next_out = buf;
 441        stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 442
 443        do {
 444                unsigned char *last_out = stream.next_out;
 445                stream.next_in = fill(1);
 446                stream.avail_in = input_len;
 447                status = git_inflate(&stream, 0);
 448                use(input_len - stream.avail_in);
 449                if (oid)
 450                        the_hash_algo->update_fn(&c, last_out, stream.next_out - last_out);
 451                if (buf == fixed_buf) {
 452                        stream.next_out = buf;
 453                        stream.avail_out = sizeof(fixed_buf);
 454                }
 455        } while (status == Z_OK);
 456        if (stream.total_out != size || status != Z_STREAM_END)
 457                bad_object(offset, _("inflate returned %d"), status);
 458        git_inflate_end(&stream);
 459        if (oid)
 460                the_hash_algo->final_fn(oid->hash, &c);
 461        return buf == fixed_buf ? NULL : buf;
 462}
 463
 464static void *unpack_raw_entry(struct object_entry *obj,
 465                              off_t *ofs_offset,
 466                              struct object_id *ref_oid,
 467                              struct object_id *oid)
 468{
 469        unsigned char *p;
 470        unsigned long size, c;
 471        off_t base_offset;
 472        unsigned shift;
 473        void *data;
 474
 475        obj->idx.offset = consumed_bytes;
 476        input_crc32 = crc32(0, NULL, 0);
 477
 478        p = fill(1);
 479        c = *p;
 480        use(1);
 481        obj->type = (c >> 4) & 7;
 482        size = (c & 15);
 483        shift = 4;
 484        while (c & 0x80) {
 485                p = fill(1);
 486                c = *p;
 487                use(1);
 488                size += (c & 0x7f) << shift;
 489                shift += 7;
 490        }
 491        obj->size = size;
 492
 493        switch (obj->type) {
 494        case OBJ_REF_DELTA:
 495                hashcpy(ref_oid->hash, fill(the_hash_algo->rawsz));
 496                use(the_hash_algo->rawsz);
 497                break;
 498        case OBJ_OFS_DELTA:
 499                p = fill(1);
 500                c = *p;
 501                use(1);
 502                base_offset = c & 127;
 503                while (c & 128) {
 504                        base_offset += 1;
 505                        if (!base_offset || MSB(base_offset, 7))
 506                                bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 507                        p = fill(1);
 508                        c = *p;
 509                        use(1);
 510                        base_offset = (base_offset << 7) + (c & 127);
 511                }
 512                *ofs_offset = obj->idx.offset - base_offset;
 513                if (*ofs_offset <= 0 || *ofs_offset >= obj->idx.offset)
 514                        bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 515                break;
 516        case OBJ_COMMIT:
 517        case OBJ_TREE:
 518        case OBJ_BLOB:
 519        case OBJ_TAG:
 520                break;
 521        default:
 522                bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 523        }
 524        obj->hdr_size = consumed_bytes - obj->idx.offset;
 525
 526        data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, oid);
 527        obj->idx.crc32 = input_crc32;
 528        return data;
 529}
 530
 531static void *unpack_data(struct object_entry *obj,
 532                         int (*consume)(const unsigned char *, unsigned long, void *),
 533                         void *cb_data)
 534{
 535        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 536        off_t len = obj[1].idx.offset - from;
 537        unsigned char *data, *inbuf;
 538        git_zstream stream;
 539        int status;
 540
 541        data = xmallocz(consume ? 64*1024 : obj->size);
 542        inbuf = xmalloc((len < 64*1024) ? (int)len : 64*1024);
 543
 544        memset(&stream, 0, sizeof(stream));
 545        git_inflate_init(&stream);
 546        stream.next_out = data;
 547        stream.avail_out = consume ? 64*1024 : obj->size;
 548
 549        do {
 550                ssize_t n = (len < 64*1024) ? (ssize_t)len : 64*1024;
 551                n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 552                if (n < 0)
 553                        die_errno(_("cannot pread pack file"));
 554                if (!n)
 555                        die(Q_("premature end of pack file, %"PRIuMAX" byte missing",
 556                               "premature end of pack file, %"PRIuMAX" bytes missing",
 557                               (unsigned int)len),
 558                            (uintmax_t)len);
 559                from += n;
 560                len -= n;
 561                stream.next_in = inbuf;
 562                stream.avail_in = n;
 563                if (!consume)
 564                        status = git_inflate(&stream, 0);
 565                else {
 566                        do {
 567                                status = git_inflate(&stream, 0);
 568                                if (consume(data, stream.next_out - data, cb_data)) {
 569                                        free(inbuf);
 570                                        free(data);
 571                                        return NULL;
 572                                }
 573                                stream.next_out = data;
 574                                stream.avail_out = 64*1024;
 575                        } while (status == Z_OK && stream.avail_in);
 576                }
 577        } while (len && status == Z_OK && !stream.avail_in);
 578
 579        /* This has been inflated OK when first encountered, so... */
 580        if (status != Z_STREAM_END || stream.total_out != obj->size)
 581                die(_("serious inflate inconsistency"));
 582
 583        git_inflate_end(&stream);
 584        free(inbuf);
 585        if (consume) {
 586                FREE_AND_NULL(data);
 587        }
 588        return data;
 589}
 590
 591static void *get_data_from_pack(struct object_entry *obj)
 592{
 593        return unpack_data(obj, NULL, NULL);
 594}
 595
 596static int compare_ofs_delta_bases(off_t offset1, off_t offset2,
 597                                   enum object_type type1,
 598                                   enum object_type type2)
 599{
 600        int cmp = type1 - type2;
 601        if (cmp)
 602                return cmp;
 603        return offset1 < offset2 ? -1 :
 604               offset1 > offset2 ?  1 :
 605               0;
 606}
 607
 608static int find_ofs_delta(const off_t offset, enum object_type type)
 609{
 610        int first = 0, last = nr_ofs_deltas;
 611
 612        while (first < last) {
 613                int next = first + (last - first) / 2;
 614                struct ofs_delta_entry *delta = &ofs_deltas[next];
 615                int cmp;
 616
 617                cmp = compare_ofs_delta_bases(offset, delta->offset,
 618                                              type, objects[delta->obj_no].type);
 619                if (!cmp)
 620                        return next;
 621                if (cmp < 0) {
 622                        last = next;
 623                        continue;
 624                }
 625                first = next+1;
 626        }
 627        return -first-1;
 628}
 629
 630static void find_ofs_delta_children(off_t offset,
 631                                    int *first_index, int *last_index,
 632                                    enum object_type type)
 633{
 634        int first = find_ofs_delta(offset, type);
 635        int last = first;
 636        int end = nr_ofs_deltas - 1;
 637
 638        if (first < 0) {
 639                *first_index = 0;
 640                *last_index = -1;
 641                return;
 642        }
 643        while (first > 0 && ofs_deltas[first - 1].offset == offset)
 644                --first;
 645        while (last < end && ofs_deltas[last + 1].offset == offset)
 646                ++last;
 647        *first_index = first;
 648        *last_index = last;
 649}
 650
 651static int compare_ref_delta_bases(const struct object_id *oid1,
 652                                   const struct object_id *oid2,
 653                                   enum object_type type1,
 654                                   enum object_type type2)
 655{
 656        int cmp = type1 - type2;
 657        if (cmp)
 658                return cmp;
 659        return oidcmp(oid1, oid2);
 660}
 661
 662static int find_ref_delta(const struct object_id *oid, enum object_type type)
 663{
 664        int first = 0, last = nr_ref_deltas;
 665
 666        while (first < last) {
 667                int next = first + (last - first) / 2;
 668                struct ref_delta_entry *delta = &ref_deltas[next];
 669                int cmp;
 670
 671                cmp = compare_ref_delta_bases(oid, &delta->oid,
 672                                              type, objects[delta->obj_no].type);
 673                if (!cmp)
 674                        return next;
 675                if (cmp < 0) {
 676                        last = next;
 677                        continue;
 678                }
 679                first = next+1;
 680        }
 681        return -first-1;
 682}
 683
 684static void find_ref_delta_children(const struct object_id *oid,
 685                                    int *first_index, int *last_index,
 686                                    enum object_type type)
 687{
 688        int first = find_ref_delta(oid, type);
 689        int last = first;
 690        int end = nr_ref_deltas - 1;
 691
 692        if (first < 0) {
 693                *first_index = 0;
 694                *last_index = -1;
 695                return;
 696        }
 697        while (first > 0 && oideq(&ref_deltas[first - 1].oid, oid))
 698                --first;
 699        while (last < end && oideq(&ref_deltas[last + 1].oid, oid))
 700                ++last;
 701        *first_index = first;
 702        *last_index = last;
 703}
 704
 705struct compare_data {
 706        struct object_entry *entry;
 707        struct git_istream *st;
 708        unsigned char *buf;
 709        unsigned long buf_size;
 710};
 711
 712static int compare_objects(const unsigned char *buf, unsigned long size,
 713                           void *cb_data)
 714{
 715        struct compare_data *data = cb_data;
 716
 717        if (data->buf_size < size) {
 718                free(data->buf);
 719                data->buf = xmalloc(size);
 720                data->buf_size = size;
 721        }
 722
 723        while (size) {
 724                ssize_t len = read_istream(data->st, data->buf, size);
 725                if (len == 0)
 726                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 727                            oid_to_hex(&data->entry->idx.oid));
 728                if (len < 0)
 729                        die(_("unable to read %s"),
 730                            oid_to_hex(&data->entry->idx.oid));
 731                if (memcmp(buf, data->buf, len))
 732                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 733                            oid_to_hex(&data->entry->idx.oid));
 734                size -= len;
 735                buf += len;
 736        }
 737        return 0;
 738}
 739
 740static int check_collison(struct object_entry *entry)
 741{
 742        struct compare_data data;
 743        enum object_type type;
 744        unsigned long size;
 745
 746        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 747                return -1;
 748
 749        memset(&data, 0, sizeof(data));
 750        data.entry = entry;
 751        data.st = open_istream(&entry->idx.oid, &type, &size, NULL);
 752        if (!data.st)
 753                return -1;
 754        if (size != entry->size || type != entry->type)
 755                die(_("SHA1 COLLISION FOUND WITH %s !"),
 756                    oid_to_hex(&entry->idx.oid));
 757        unpack_data(entry, compare_objects, &data);
 758        close_istream(data.st);
 759        free(data.buf);
 760        return 0;
 761}
 762
 763static void sha1_object(const void *data, struct object_entry *obj_entry,
 764                        unsigned long size, enum object_type type,
 765                        const struct object_id *oid)
 766{
 767        void *new_data = NULL;
 768        int collision_test_needed = 0;
 769
 770        assert(data || obj_entry);
 771
 772        if (startup_info->have_repository) {
 773                read_lock();
 774                collision_test_needed =
 775                        has_object_file_with_flags(oid, OBJECT_INFO_QUICK);
 776                read_unlock();
 777        }
 778
 779        if (collision_test_needed && !data) {
 780                read_lock();
 781                if (!check_collison(obj_entry))
 782                        collision_test_needed = 0;
 783                read_unlock();
 784        }
 785        if (collision_test_needed) {
 786                void *has_data;
 787                enum object_type has_type;
 788                unsigned long has_size;
 789                read_lock();
 790                has_type = oid_object_info(the_repository, oid, &has_size);
 791                if (has_type < 0)
 792                        die(_("cannot read existing object info %s"), oid_to_hex(oid));
 793                if (has_type != type || has_size != size)
 794                        die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 795                has_data = read_object_file(oid, &has_type, &has_size);
 796                read_unlock();
 797                if (!data)
 798                        data = new_data = get_data_from_pack(obj_entry);
 799                if (!has_data)
 800                        die(_("cannot read existing object %s"), oid_to_hex(oid));
 801                if (size != has_size || type != has_type ||
 802                    memcmp(data, has_data, size) != 0)
 803                        die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 804                free(has_data);
 805        }
 806
 807        if (strict || do_fsck_object) {
 808                read_lock();
 809                if (type == OBJ_BLOB) {
 810                        struct blob *blob = lookup_blob(the_repository, oid);
 811                        if (blob)
 812                                blob->object.flags |= FLAG_CHECKED;
 813                        else
 814                                die(_("invalid blob object %s"), oid_to_hex(oid));
 815                        if (do_fsck_object &&
 816                            fsck_object(&blob->object, (void *)data, size, &fsck_options))
 817                                die(_("fsck error in packed object"));
 818                } else {
 819                        struct object *obj;
 820                        int eaten;
 821                        void *buf = (void *) data;
 822
 823                        assert(data && "data can only be NULL for large _blobs_");
 824
 825                        /*
 826                         * we do not need to free the memory here, as the
 827                         * buf is deleted by the caller.
 828                         */
 829                        obj = parse_object_buffer(the_repository, oid, type,
 830                                                  size, buf,
 831                                                  &eaten);
 832                        if (!obj)
 833                                die(_("invalid %s"), type_name(type));
 834                        if (do_fsck_object &&
 835                            fsck_object(obj, buf, size, &fsck_options))
 836                                die(_("fsck error in packed object"));
 837                        if (strict && fsck_walk(obj, NULL, &fsck_options))
 838                                die(_("Not all child objects of %s are reachable"), oid_to_hex(&obj->oid));
 839
 840                        if (obj->type == OBJ_TREE) {
 841                                struct tree *item = (struct tree *) obj;
 842                                item->buffer = NULL;
 843                                obj->parsed = 0;
 844                        }
 845                        if (obj->type == OBJ_COMMIT) {
 846                                struct commit *commit = (struct commit *) obj;
 847                                if (detach_commit_buffer(commit, NULL) != data)
 848                                        BUG("parse_object_buffer transmogrified our buffer");
 849                        }
 850                        obj->flags |= FLAG_CHECKED;
 851                }
 852                read_unlock();
 853        }
 854
 855        free(new_data);
 856}
 857
 858/*
 859 * This function is part of find_unresolved_deltas(). There are two
 860 * walkers going in the opposite ways.
 861 *
 862 * The first one in find_unresolved_deltas() traverses down from
 863 * parent node to children, deflating nodes along the way. However,
 864 * memory for deflated nodes is limited by delta_base_cache_limit, so
 865 * at some point parent node's deflated content may be freed.
 866 *
 867 * The second walker is this function, which goes from current node up
 868 * to top parent if necessary to deflate the node. In normal
 869 * situation, its parent node would be already deflated, so it just
 870 * needs to apply delta.
 871 *
 872 * In the worst case scenario, parent node is no longer deflated because
 873 * we're running out of delta_base_cache_limit; we need to re-deflate
 874 * parents, possibly up to the top base.
 875 *
 876 * All deflated objects here are subject to be freed if we exceed
 877 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 878 * just need to make sure the last node is not freed.
 879 */
 880static void *get_base_data(struct base_data *c)
 881{
 882        if (!c->data) {
 883                struct object_entry *obj = c->obj;
 884                struct base_data **delta = NULL;
 885                int delta_nr = 0, delta_alloc = 0;
 886
 887                while (is_delta_type(c->obj->type) && !c->data) {
 888                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 889                        delta[delta_nr++] = c;
 890                        c = c->base;
 891                }
 892                if (!delta_nr) {
 893                        c->data = get_data_from_pack(obj);
 894                        c->size = obj->size;
 895                        get_thread_data()->base_cache_used += c->size;
 896                        prune_base_data(c);
 897                }
 898                for (; delta_nr > 0; delta_nr--) {
 899                        void *base, *raw;
 900                        c = delta[delta_nr - 1];
 901                        obj = c->obj;
 902                        base = get_base_data(c->base);
 903                        raw = get_data_from_pack(obj);
 904                        c->data = patch_delta(
 905                                base, c->base->size,
 906                                raw, obj->size,
 907                                &c->size);
 908                        free(raw);
 909                        if (!c->data)
 910                                bad_object(obj->idx.offset, _("failed to apply delta"));
 911                        get_thread_data()->base_cache_used += c->size;
 912                        prune_base_data(c);
 913                }
 914                free(delta);
 915        }
 916        return c->data;
 917}
 918
 919static void resolve_delta(struct object_entry *delta_obj,
 920                          struct base_data *base, struct base_data *result)
 921{
 922        void *base_data, *delta_data;
 923
 924        if (show_stat) {
 925                int i = delta_obj - objects;
 926                int j = base->obj - objects;
 927                obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 928                deepest_delta_lock();
 929                if (deepest_delta < obj_stat[i].delta_depth)
 930                        deepest_delta = obj_stat[i].delta_depth;
 931                deepest_delta_unlock();
 932                obj_stat[i].base_object_no = j;
 933        }
 934        delta_data = get_data_from_pack(delta_obj);
 935        base_data = get_base_data(base);
 936        result->obj = delta_obj;
 937        result->data = patch_delta(base_data, base->size,
 938                                   delta_data, delta_obj->size, &result->size);
 939        free(delta_data);
 940        if (!result->data)
 941                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 942        hash_object_file(result->data, result->size,
 943                         type_name(delta_obj->real_type), &delta_obj->idx.oid);
 944        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 945                    &delta_obj->idx.oid);
 946        counter_lock();
 947        nr_resolved_deltas++;
 948        counter_unlock();
 949}
 950
 951/*
 952 * Standard boolean compare-and-swap: atomically check whether "*type" is
 953 * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 954 * and return false.
 955 */
 956static int compare_and_swap_type(signed char *type,
 957                                 enum object_type want,
 958                                 enum object_type set)
 959{
 960        enum object_type old;
 961
 962        type_cas_lock();
 963        old = *type;
 964        if (old == want)
 965                *type = set;
 966        type_cas_unlock();
 967
 968        return old == want;
 969}
 970
 971static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 972                                                  struct base_data *prev_base)
 973{
 974        if (base->ref_last == -1 && base->ofs_last == -1) {
 975                find_ref_delta_children(&base->obj->idx.oid,
 976                                        &base->ref_first, &base->ref_last,
 977                                        OBJ_REF_DELTA);
 978
 979                find_ofs_delta_children(base->obj->idx.offset,
 980                                        &base->ofs_first, &base->ofs_last,
 981                                        OBJ_OFS_DELTA);
 982
 983                if (base->ref_last == -1 && base->ofs_last == -1) {
 984                        free(base->data);
 985                        return NULL;
 986                }
 987
 988                link_base_data(prev_base, base);
 989        }
 990
 991        if (base->ref_first <= base->ref_last) {
 992                struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
 993                struct base_data *result = alloc_base_data();
 994
 995                if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
 996                                           base->obj->real_type))
 997                        BUG("child->real_type != OBJ_REF_DELTA");
 998
 999                resolve_delta(child, base, result);
1000                if (base->ref_first == base->ref_last && base->ofs_last == -1)
1001                        free_base_data(base);
1002
1003                base->ref_first++;
1004                return result;
1005        }
1006
1007        if (base->ofs_first <= base->ofs_last) {
1008                struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
1009                struct base_data *result = alloc_base_data();
1010
1011                assert(child->real_type == OBJ_OFS_DELTA);
1012                child->real_type = base->obj->real_type;
1013                resolve_delta(child, base, result);
1014                if (base->ofs_first == base->ofs_last)
1015                        free_base_data(base);
1016
1017                base->ofs_first++;
1018                return result;
1019        }
1020
1021        unlink_base_data(base);
1022        return NULL;
1023}
1024
1025static void find_unresolved_deltas(struct base_data *base)
1026{
1027        struct base_data *new_base, *prev_base = NULL;
1028        for (;;) {
1029                new_base = find_unresolved_deltas_1(base, prev_base);
1030
1031                if (new_base) {
1032                        prev_base = base;
1033                        base = new_base;
1034                } else {
1035                        free(base);
1036                        base = prev_base;
1037                        if (!base)
1038                                return;
1039                        prev_base = base->base;
1040                }
1041        }
1042}
1043
1044static int compare_ofs_delta_entry(const void *a, const void *b)
1045{
1046        const struct ofs_delta_entry *delta_a = a;
1047        const struct ofs_delta_entry *delta_b = b;
1048
1049        return delta_a->offset < delta_b->offset ? -1 :
1050               delta_a->offset > delta_b->offset ?  1 :
1051               0;
1052}
1053
1054static int compare_ref_delta_entry(const void *a, const void *b)
1055{
1056        const struct ref_delta_entry *delta_a = a;
1057        const struct ref_delta_entry *delta_b = b;
1058
1059        return oidcmp(&delta_a->oid, &delta_b->oid);
1060}
1061
1062static void resolve_base(struct object_entry *obj)
1063{
1064        struct base_data *base_obj = alloc_base_data();
1065        base_obj->obj = obj;
1066        base_obj->data = NULL;
1067        find_unresolved_deltas(base_obj);
1068}
1069
1070static void *threaded_second_pass(void *data)
1071{
1072        set_thread_data(data);
1073        for (;;) {
1074                int i;
1075                counter_lock();
1076                display_progress(progress, nr_resolved_deltas);
1077                counter_unlock();
1078                work_lock();
1079                while (nr_dispatched < nr_objects &&
1080                       is_delta_type(objects[nr_dispatched].type))
1081                        nr_dispatched++;
1082                if (nr_dispatched >= nr_objects) {
1083                        work_unlock();
1084                        break;
1085                }
1086                i = nr_dispatched++;
1087                work_unlock();
1088
1089                resolve_base(&objects[i]);
1090        }
1091        return NULL;
1092}
1093
1094/*
1095 * First pass:
1096 * - find locations of all objects;
1097 * - calculate SHA1 of all non-delta objects;
1098 * - remember base (SHA1 or offset) for all deltas.
1099 */
1100static void parse_pack_objects(unsigned char *hash)
1101{
1102        int i, nr_delays = 0;
1103        struct ofs_delta_entry *ofs_delta = ofs_deltas;
1104        struct object_id ref_delta_oid;
1105        struct stat st;
1106
1107        if (verbose)
1108                progress = start_progress(
1109                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1110                                nr_objects);
1111        for (i = 0; i < nr_objects; i++) {
1112                struct object_entry *obj = &objects[i];
1113                void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1114                                              &ref_delta_oid,
1115                                              &obj->idx.oid);
1116                obj->real_type = obj->type;
1117                if (obj->type == OBJ_OFS_DELTA) {
1118                        nr_ofs_deltas++;
1119                        ofs_delta->obj_no = i;
1120                        ofs_delta++;
1121                } else if (obj->type == OBJ_REF_DELTA) {
1122                        ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1123                        oidcpy(&ref_deltas[nr_ref_deltas].oid, &ref_delta_oid);
1124                        ref_deltas[nr_ref_deltas].obj_no = i;
1125                        nr_ref_deltas++;
1126                } else if (!data) {
1127                        /* large blobs, check later */
1128                        obj->real_type = OBJ_BAD;
1129                        nr_delays++;
1130                } else
1131                        sha1_object(data, NULL, obj->size, obj->type,
1132                                    &obj->idx.oid);
1133                free(data);
1134                display_progress(progress, i+1);
1135        }
1136        objects[i].idx.offset = consumed_bytes;
1137        stop_progress(&progress);
1138
1139        /* Check pack integrity */
1140        flush();
1141        the_hash_algo->final_fn(hash, &input_ctx);
1142        if (!hasheq(fill(the_hash_algo->rawsz), hash))
1143                die(_("pack is corrupted (SHA1 mismatch)"));
1144        use(the_hash_algo->rawsz);
1145
1146        /* If input_fd is a file, we should have reached its end now. */
1147        if (fstat(input_fd, &st))
1148                die_errno(_("cannot fstat packfile"));
1149        if (S_ISREG(st.st_mode) &&
1150                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1151                die(_("pack has junk at the end"));
1152
1153        for (i = 0; i < nr_objects; i++) {
1154                struct object_entry *obj = &objects[i];
1155                if (obj->real_type != OBJ_BAD)
1156                        continue;
1157                obj->real_type = obj->type;
1158                sha1_object(NULL, obj, obj->size, obj->type,
1159                            &obj->idx.oid);
1160                nr_delays--;
1161        }
1162        if (nr_delays)
1163                die(_("confusion beyond insanity in parse_pack_objects()"));
1164}
1165
1166/*
1167 * Second pass:
1168 * - for all non-delta objects, look if it is used as a base for
1169 *   deltas;
1170 * - if used as a base, uncompress the object and apply all deltas,
1171 *   recursively checking if the resulting object is used as a base
1172 *   for some more deltas.
1173 */
1174static void resolve_deltas(void)
1175{
1176        int i;
1177
1178        if (!nr_ofs_deltas && !nr_ref_deltas)
1179                return;
1180
1181        /* Sort deltas by base SHA1/offset for fast searching */
1182        QSORT(ofs_deltas, nr_ofs_deltas, compare_ofs_delta_entry);
1183        QSORT(ref_deltas, nr_ref_deltas, compare_ref_delta_entry);
1184
1185        if (verbose || show_resolving_progress)
1186                progress = start_progress(_("Resolving deltas"),
1187                                          nr_ref_deltas + nr_ofs_deltas);
1188
1189        nr_dispatched = 0;
1190        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1191                init_thread();
1192                for (i = 0; i < nr_threads; i++) {
1193                        int ret = pthread_create(&thread_data[i].thread, NULL,
1194                                                 threaded_second_pass, thread_data + i);
1195                        if (ret)
1196                                die(_("unable to create thread: %s"),
1197                                    strerror(ret));
1198                }
1199                for (i = 0; i < nr_threads; i++)
1200                        pthread_join(thread_data[i].thread, NULL);
1201                cleanup_thread();
1202                return;
1203        }
1204
1205        for (i = 0; i < nr_objects; i++) {
1206                struct object_entry *obj = &objects[i];
1207
1208                if (is_delta_type(obj->type))
1209                        continue;
1210                resolve_base(obj);
1211                display_progress(progress, nr_resolved_deltas);
1212        }
1213}
1214
1215/*
1216 * Third pass:
1217 * - append objects to convert thin pack to full pack if required
1218 * - write the final pack hash
1219 */
1220static void fix_unresolved_deltas(struct hashfile *f);
1221static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_hash)
1222{
1223        if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1224                stop_progress(&progress);
1225                /* Flush remaining pack final hash. */
1226                flush();
1227                return;
1228        }
1229
1230        if (fix_thin_pack) {
1231                struct hashfile *f;
1232                unsigned char read_hash[GIT_MAX_RAWSZ], tail_hash[GIT_MAX_RAWSZ];
1233                struct strbuf msg = STRBUF_INIT;
1234                int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1235                int nr_objects_initial = nr_objects;
1236                if (nr_unresolved <= 0)
1237                        die(_("confusion beyond insanity"));
1238                REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1239                memset(objects + nr_objects + 1, 0,
1240                       nr_unresolved * sizeof(*objects));
1241                f = hashfd(output_fd, curr_pack);
1242                fix_unresolved_deltas(f);
1243                strbuf_addf(&msg, Q_("completed with %d local object",
1244                                     "completed with %d local objects",
1245                                     nr_objects - nr_objects_initial),
1246                            nr_objects - nr_objects_initial);
1247                stop_progress_msg(&progress, msg.buf);
1248                strbuf_release(&msg);
1249                finalize_hashfile(f, tail_hash, 0);
1250                hashcpy(read_hash, pack_hash);
1251                fixup_pack_header_footer(output_fd, pack_hash,
1252                                         curr_pack, nr_objects,
1253                                         read_hash, consumed_bytes-the_hash_algo->rawsz);
1254                if (!hasheq(read_hash, tail_hash))
1255                        die(_("Unexpected tail checksum for %s "
1256                              "(disk corruption?)"), curr_pack);
1257        }
1258        if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1259                die(Q_("pack has %d unresolved delta",
1260                       "pack has %d unresolved deltas",
1261                       nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1262                    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1263}
1264
1265static int write_compressed(struct hashfile *f, void *in, unsigned int size)
1266{
1267        git_zstream stream;
1268        int status;
1269        unsigned char outbuf[4096];
1270
1271        git_deflate_init(&stream, zlib_compression_level);
1272        stream.next_in = in;
1273        stream.avail_in = size;
1274
1275        do {
1276                stream.next_out = outbuf;
1277                stream.avail_out = sizeof(outbuf);
1278                status = git_deflate(&stream, Z_FINISH);
1279                hashwrite(f, outbuf, sizeof(outbuf) - stream.avail_out);
1280        } while (status == Z_OK);
1281
1282        if (status != Z_STREAM_END)
1283                die(_("unable to deflate appended object (%d)"), status);
1284        size = stream.total_out;
1285        git_deflate_end(&stream);
1286        return size;
1287}
1288
1289static struct object_entry *append_obj_to_pack(struct hashfile *f,
1290                               const unsigned char *sha1, void *buf,
1291                               unsigned long size, enum object_type type)
1292{
1293        struct object_entry *obj = &objects[nr_objects++];
1294        unsigned char header[10];
1295        unsigned long s = size;
1296        int n = 0;
1297        unsigned char c = (type << 4) | (s & 15);
1298        s >>= 4;
1299        while (s) {
1300                header[n++] = c | 0x80;
1301                c = s & 0x7f;
1302                s >>= 7;
1303        }
1304        header[n++] = c;
1305        crc32_begin(f);
1306        hashwrite(f, header, n);
1307        obj[0].size = size;
1308        obj[0].hdr_size = n;
1309        obj[0].type = type;
1310        obj[0].real_type = type;
1311        obj[1].idx.offset = obj[0].idx.offset + n;
1312        obj[1].idx.offset += write_compressed(f, buf, size);
1313        obj[0].idx.crc32 = crc32_end(f);
1314        hashflush(f);
1315        hashcpy(obj->idx.oid.hash, sha1);
1316        return obj;
1317}
1318
1319static int delta_pos_compare(const void *_a, const void *_b)
1320{
1321        struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1322        struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1323        return a->obj_no - b->obj_no;
1324}
1325
1326static void fix_unresolved_deltas(struct hashfile *f)
1327{
1328        struct ref_delta_entry **sorted_by_pos;
1329        int i;
1330
1331        /*
1332         * Since many unresolved deltas may well be themselves base objects
1333         * for more unresolved deltas, we really want to include the
1334         * smallest number of base objects that would cover as much delta
1335         * as possible by picking the
1336         * trunc deltas first, allowing for other deltas to resolve without
1337         * additional base objects.  Since most base objects are to be found
1338         * before deltas depending on them, a good heuristic is to start
1339         * resolving deltas in the same order as their position in the pack.
1340         */
1341        ALLOC_ARRAY(sorted_by_pos, nr_ref_deltas);
1342        for (i = 0; i < nr_ref_deltas; i++)
1343                sorted_by_pos[i] = &ref_deltas[i];
1344        QSORT(sorted_by_pos, nr_ref_deltas, delta_pos_compare);
1345
1346        for (i = 0; i < nr_ref_deltas; i++) {
1347                struct ref_delta_entry *d = sorted_by_pos[i];
1348                enum object_type type;
1349                struct base_data *base_obj = alloc_base_data();
1350
1351                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1352                        continue;
1353                base_obj->data = read_object_file(&d->oid, &type,
1354                                                  &base_obj->size);
1355                if (!base_obj->data)
1356                        continue;
1357
1358                if (check_object_signature(&d->oid, base_obj->data,
1359                                base_obj->size, type_name(type)))
1360                        die(_("local object %s is corrupt"), oid_to_hex(&d->oid));
1361                base_obj->obj = append_obj_to_pack(f, d->oid.hash,
1362                                        base_obj->data, base_obj->size, type);
1363                find_unresolved_deltas(base_obj);
1364                display_progress(progress, nr_resolved_deltas);
1365        }
1366        free(sorted_by_pos);
1367}
1368
1369static const char *derive_filename(const char *pack_name, const char *suffix,
1370                                   struct strbuf *buf)
1371{
1372        size_t len;
1373        if (!strip_suffix(pack_name, ".pack", &len))
1374                die(_("packfile name '%s' does not end with '.pack'"),
1375                    pack_name);
1376        strbuf_add(buf, pack_name, len);
1377        strbuf_addch(buf, '.');
1378        strbuf_addstr(buf, suffix);
1379        return buf->buf;
1380}
1381
1382static void write_special_file(const char *suffix, const char *msg,
1383                               const char *pack_name, const unsigned char *hash,
1384                               const char **report)
1385{
1386        struct strbuf name_buf = STRBUF_INIT;
1387        const char *filename;
1388        int fd;
1389        int msg_len = strlen(msg);
1390
1391        if (pack_name)
1392                filename = derive_filename(pack_name, suffix, &name_buf);
1393        else
1394                filename = odb_pack_name(&name_buf, hash, suffix);
1395
1396        fd = odb_pack_keep(filename);
1397        if (fd < 0) {
1398                if (errno != EEXIST)
1399                        die_errno(_("cannot write %s file '%s'"),
1400                                  suffix, filename);
1401        } else {
1402                if (msg_len > 0) {
1403                        write_or_die(fd, msg, msg_len);
1404                        write_or_die(fd, "\n", 1);
1405                }
1406                if (close(fd) != 0)
1407                        die_errno(_("cannot close written %s file '%s'"),
1408                                  suffix, filename);
1409                if (report)
1410                        *report = suffix;
1411        }
1412        strbuf_release(&name_buf);
1413}
1414
1415static void final(const char *final_pack_name, const char *curr_pack_name,
1416                  const char *final_index_name, const char *curr_index_name,
1417                  const char *keep_msg, const char *promisor_msg,
1418                  unsigned char *hash)
1419{
1420        const char *report = "pack";
1421        struct strbuf pack_name = STRBUF_INIT;
1422        struct strbuf index_name = STRBUF_INIT;
1423        int err;
1424
1425        if (!from_stdin) {
1426                close(input_fd);
1427        } else {
1428                fsync_or_die(output_fd, curr_pack_name);
1429                err = close(output_fd);
1430                if (err)
1431                        die_errno(_("error while closing pack file"));
1432        }
1433
1434        if (keep_msg)
1435                write_special_file("keep", keep_msg, final_pack_name, hash,
1436                                   &report);
1437        if (promisor_msg)
1438                write_special_file("promisor", promisor_msg, final_pack_name,
1439                                   hash, NULL);
1440
1441        if (final_pack_name != curr_pack_name) {
1442                if (!final_pack_name)
1443                        final_pack_name = odb_pack_name(&pack_name, hash, "pack");
1444                if (finalize_object_file(curr_pack_name, final_pack_name))
1445                        die(_("cannot store pack file"));
1446        } else if (from_stdin)
1447                chmod(final_pack_name, 0444);
1448
1449        if (final_index_name != curr_index_name) {
1450                if (!final_index_name)
1451                        final_index_name = odb_pack_name(&index_name, hash, "idx");
1452                if (finalize_object_file(curr_index_name, final_index_name))
1453                        die(_("cannot store index file"));
1454        } else
1455                chmod(final_index_name, 0444);
1456
1457        if (do_fsck_object) {
1458                struct packed_git *p;
1459                p = add_packed_git(final_index_name, strlen(final_index_name), 0);
1460                if (p)
1461                        install_packed_git(the_repository, p);
1462        }
1463
1464        if (!from_stdin) {
1465                printf("%s\n", sha1_to_hex(hash));
1466        } else {
1467                struct strbuf buf = STRBUF_INIT;
1468
1469                strbuf_addf(&buf, "%s\t%s\n", report, sha1_to_hex(hash));
1470                write_or_die(1, buf.buf, buf.len);
1471                strbuf_release(&buf);
1472
1473                /*
1474                 * Let's just mimic git-unpack-objects here and write
1475                 * the last part of the input buffer to stdout.
1476                 */
1477                while (input_len) {
1478                        err = xwrite(1, input_buffer + input_offset, input_len);
1479                        if (err <= 0)
1480                                break;
1481                        input_len -= err;
1482                        input_offset += err;
1483                }
1484        }
1485
1486        strbuf_release(&index_name);
1487        strbuf_release(&pack_name);
1488}
1489
1490static int git_index_pack_config(const char *k, const char *v, void *cb)
1491{
1492        struct pack_idx_option *opts = cb;
1493
1494        if (!strcmp(k, "pack.indexversion")) {
1495                opts->version = git_config_int(k, v);
1496                if (opts->version > 2)
1497                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1498                return 0;
1499        }
1500        if (!strcmp(k, "pack.threads")) {
1501                nr_threads = git_config_int(k, v);
1502                if (nr_threads < 0)
1503                        die(_("invalid number of threads specified (%d)"),
1504                            nr_threads);
1505                if (!HAVE_THREADS && nr_threads != 1) {
1506                        warning(_("no threads support, ignoring %s"), k);
1507                        nr_threads = 1;
1508                }
1509                return 0;
1510        }
1511        return git_default_config(k, v, cb);
1512}
1513
1514static int cmp_uint32(const void *a_, const void *b_)
1515{
1516        uint32_t a = *((uint32_t *)a_);
1517        uint32_t b = *((uint32_t *)b_);
1518
1519        return (a < b) ? -1 : (a != b);
1520}
1521
1522static void read_v2_anomalous_offsets(struct packed_git *p,
1523                                      struct pack_idx_option *opts)
1524{
1525        const uint32_t *idx1, *idx2;
1526        uint32_t i;
1527        const uint32_t hashwords = the_hash_algo->rawsz / sizeof(uint32_t);
1528
1529        /* The address of the 4-byte offset table */
1530        idx1 = (((const uint32_t *)p->index_data)
1531                + 2 /* 8-byte header */
1532                + 256 /* fan out */
1533                + hashwords * p->num_objects /* object ID table */
1534                + p->num_objects /* CRC32 table */
1535                );
1536
1537        /* The address of the 8-byte offset table */
1538        idx2 = idx1 + p->num_objects;
1539
1540        for (i = 0; i < p->num_objects; i++) {
1541                uint32_t off = ntohl(idx1[i]);
1542                if (!(off & 0x80000000))
1543                        continue;
1544                off = off & 0x7fffffff;
1545                check_pack_index_ptr(p, &idx2[off * 2]);
1546                if (idx2[off * 2])
1547                        continue;
1548                /*
1549                 * The real offset is ntohl(idx2[off * 2]) in high 4
1550                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1551                 * octets.  But idx2[off * 2] is Zero!!!
1552                 */
1553                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1554                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1555        }
1556
1557        QSORT(opts->anomaly, opts->anomaly_nr, cmp_uint32);
1558}
1559
1560static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1561{
1562        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1563
1564        if (!p)
1565                die(_("Cannot open existing pack file '%s'"), pack_name);
1566        if (open_pack_index(p))
1567                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1568
1569        /* Read the attributes from the existing idx file */
1570        opts->version = p->index_version;
1571
1572        if (opts->version == 2)
1573                read_v2_anomalous_offsets(p, opts);
1574
1575        /*
1576         * Get rid of the idx file as we do not need it anymore.
1577         * NEEDSWORK: extract this bit from free_pack_by_name() in
1578         * sha1-file.c, perhaps?  It shouldn't matter very much as we
1579         * know we haven't installed this pack (hence we never have
1580         * read anything from it).
1581         */
1582        close_pack_index(p);
1583        free(p);
1584}
1585
1586static void show_pack_info(int stat_only)
1587{
1588        int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1589        unsigned long *chain_histogram = NULL;
1590
1591        if (deepest_delta)
1592                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1593
1594        for (i = 0; i < nr_objects; i++) {
1595                struct object_entry *obj = &objects[i];
1596
1597                if (is_delta_type(obj->type))
1598                        chain_histogram[obj_stat[i].delta_depth - 1]++;
1599                if (stat_only)
1600                        continue;
1601                printf("%s %-6s %"PRIuMAX" %"PRIuMAX" %"PRIuMAX,
1602                       oid_to_hex(&obj->idx.oid),
1603                       type_name(obj->real_type), (uintmax_t)obj->size,
1604                       (uintmax_t)(obj[1].idx.offset - obj->idx.offset),
1605                       (uintmax_t)obj->idx.offset);
1606                if (is_delta_type(obj->type)) {
1607                        struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1608                        printf(" %u %s", obj_stat[i].delta_depth,
1609                               oid_to_hex(&bobj->idx.oid));
1610                }
1611                putchar('\n');
1612        }
1613
1614        if (baseobjects)
1615                printf_ln(Q_("non delta: %d object",
1616                             "non delta: %d objects",
1617                             baseobjects),
1618                          baseobjects);
1619        for (i = 0; i < deepest_delta; i++) {
1620                if (!chain_histogram[i])
1621                        continue;
1622                printf_ln(Q_("chain length = %d: %lu object",
1623                             "chain length = %d: %lu objects",
1624                             chain_histogram[i]),
1625                          i + 1,
1626                          chain_histogram[i]);
1627        }
1628}
1629
1630int cmd_index_pack(int argc, const char **argv, const char *prefix)
1631{
1632        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1633        const char *curr_index;
1634        const char *index_name = NULL, *pack_name = NULL;
1635        const char *keep_msg = NULL;
1636        const char *promisor_msg = NULL;
1637        struct strbuf index_name_buf = STRBUF_INIT;
1638        struct pack_idx_entry **idx_objects;
1639        struct pack_idx_option opts;
1640        unsigned char pack_hash[GIT_MAX_RAWSZ];
1641        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1642        int report_end_of_input = 0;
1643
1644        /*
1645         * index-pack never needs to fetch missing objects, since it only
1646         * accesses the repo to do hash collision checks
1647         */
1648        fetch_if_missing = 0;
1649
1650        if (argc == 2 && !strcmp(argv[1], "-h"))
1651                usage(index_pack_usage);
1652
1653        read_replace_refs = 0;
1654        fsck_options.walk = mark_link;
1655
1656        reset_pack_idx_option(&opts);
1657        git_config(git_index_pack_config, &opts);
1658        if (prefix && chdir(prefix))
1659                die(_("Cannot come back to cwd"));
1660
1661        for (i = 1; i < argc; i++) {
1662                const char *arg = argv[i];
1663
1664                if (*arg == '-') {
1665                        if (!strcmp(arg, "--stdin")) {
1666                                from_stdin = 1;
1667                        } else if (!strcmp(arg, "--fix-thin")) {
1668                                fix_thin_pack = 1;
1669                        } else if (skip_to_optional_arg(arg, "--strict", &arg)) {
1670                                strict = 1;
1671                                do_fsck_object = 1;
1672                                fsck_set_msg_types(&fsck_options, arg);
1673                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1674                                strict = 1;
1675                                check_self_contained_and_connected = 1;
1676                        } else if (!strcmp(arg, "--fsck-objects")) {
1677                                do_fsck_object = 1;
1678                        } else if (!strcmp(arg, "--verify")) {
1679                                verify = 1;
1680                        } else if (!strcmp(arg, "--verify-stat")) {
1681                                verify = 1;
1682                                show_stat = 1;
1683                        } else if (!strcmp(arg, "--verify-stat-only")) {
1684                                verify = 1;
1685                                show_stat = 1;
1686                                stat_only = 1;
1687                        } else if (skip_to_optional_arg(arg, "--keep", &keep_msg)) {
1688                                ; /* nothing to do */
1689                        } else if (skip_to_optional_arg(arg, "--promisor", &promisor_msg)) {
1690                                ; /* already parsed */
1691                        } else if (starts_with(arg, "--threads=")) {
1692                                char *end;
1693                                nr_threads = strtoul(arg+10, &end, 0);
1694                                if (!arg[10] || *end || nr_threads < 0)
1695                                        usage(index_pack_usage);
1696                                if (!HAVE_THREADS && nr_threads != 1) {
1697                                        warning(_("no threads support, ignoring %s"), arg);
1698                                        nr_threads = 1;
1699                                }
1700                        } else if (starts_with(arg, "--pack_header=")) {
1701                                struct pack_header *hdr;
1702                                char *c;
1703
1704                                hdr = (struct pack_header *)input_buffer;
1705                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1706                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1707                                if (*c != ',')
1708                                        die(_("bad %s"), arg);
1709                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1710                                if (*c)
1711                                        die(_("bad %s"), arg);
1712                                input_len = sizeof(*hdr);
1713                        } else if (!strcmp(arg, "-v")) {
1714                                verbose = 1;
1715                        } else if (!strcmp(arg, "--show-resolving-progress")) {
1716                                show_resolving_progress = 1;
1717                        } else if (!strcmp(arg, "--report-end-of-input")) {
1718                                report_end_of_input = 1;
1719                        } else if (!strcmp(arg, "-o")) {
1720                                if (index_name || (i+1) >= argc)
1721                                        usage(index_pack_usage);
1722                                index_name = argv[++i];
1723                        } else if (starts_with(arg, "--index-version=")) {
1724                                char *c;
1725                                opts.version = strtoul(arg + 16, &c, 10);
1726                                if (opts.version > 2)
1727                                        die(_("bad %s"), arg);
1728                                if (*c == ',')
1729                                        opts.off32_limit = strtoul(c+1, &c, 0);
1730                                if (*c || opts.off32_limit & 0x80000000)
1731                                        die(_("bad %s"), arg);
1732                        } else if (skip_prefix(arg, "--max-input-size=", &arg)) {
1733                                max_input_size = strtoumax(arg, NULL, 10);
1734                        } else
1735                                usage(index_pack_usage);
1736                        continue;
1737                }
1738
1739                if (pack_name)
1740                        usage(index_pack_usage);
1741                pack_name = arg;
1742        }
1743
1744        if (!pack_name && !from_stdin)
1745                usage(index_pack_usage);
1746        if (fix_thin_pack && !from_stdin)
1747                die(_("--fix-thin cannot be used without --stdin"));
1748        if (from_stdin && !startup_info->have_repository)
1749                die(_("--stdin requires a git repository"));
1750        if (!index_name && pack_name)
1751                index_name = derive_filename(pack_name, "idx", &index_name_buf);
1752
1753        if (verify) {
1754                if (!index_name)
1755                        die(_("--verify with no packfile name given"));
1756                read_idx_option(&opts, index_name);
1757                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1758        }
1759        if (strict)
1760                opts.flags |= WRITE_IDX_STRICT;
1761
1762        if (HAVE_THREADS && !nr_threads) {
1763                nr_threads = online_cpus();
1764                /* An experiment showed that more threads does not mean faster */
1765                if (nr_threads > 3)
1766                        nr_threads = 3;
1767        }
1768
1769        curr_pack = open_pack_file(pack_name);
1770        parse_pack_header();
1771        objects = xcalloc(st_add(nr_objects, 1), sizeof(struct object_entry));
1772        if (show_stat)
1773                obj_stat = xcalloc(st_add(nr_objects, 1), sizeof(struct object_stat));
1774        ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
1775        parse_pack_objects(pack_hash);
1776        if (report_end_of_input)
1777                write_in_full(2, "\0", 1);
1778        resolve_deltas();
1779        conclude_pack(fix_thin_pack, curr_pack, pack_hash);
1780        free(ofs_deltas);
1781        free(ref_deltas);
1782        if (strict)
1783                foreign_nr = check_objects();
1784
1785        if (show_stat)
1786                show_pack_info(stat_only);
1787
1788        ALLOC_ARRAY(idx_objects, nr_objects);
1789        for (i = 0; i < nr_objects; i++)
1790                idx_objects[i] = &objects[i].idx;
1791        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_hash);
1792        free(idx_objects);
1793
1794        if (!verify)
1795                final(pack_name, curr_pack,
1796                      index_name, curr_index,
1797                      keep_msg, promisor_msg,
1798                      pack_hash);
1799        else
1800                close(input_fd);
1801
1802        if (do_fsck_object && fsck_finish(&fsck_options))
1803                die(_("fsck error in pack objects"));
1804
1805        free(objects);
1806        strbuf_release(&index_name_buf);
1807        if (pack_name == NULL)
1808                free((void *) curr_pack);
1809        if (index_name == NULL)
1810                free((void *) curr_index);
1811
1812        /*
1813         * Let the caller know this pack is not self contained
1814         */
1815        if (check_self_contained_and_connected && foreign_nr)
1816                return 1;
1817
1818        return 0;
1819}