builtin / index-pack.con commit Merge branch 'bb/unicode-12.1-reiwa' into maint (7a779ca)
   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
 223        if (verbose)
 224                progress = start_delayed_progress(_("Checking objects"), max);
 225
 226        for (i = 0; i < max; i++) {
 227                foreign_nr += check_object(get_indexed_object(i));
 228                display_progress(progress, i + 1);
 229        }
 230
 231        stop_progress(&progress);
 232        return foreign_nr;
 233}
 234
 235
 236/* Discard current buffer used content. */
 237static void flush(void)
 238{
 239        if (input_offset) {
 240                if (output_fd >= 0)
 241                        write_or_die(output_fd, input_buffer, input_offset);
 242                the_hash_algo->update_fn(&input_ctx, input_buffer, input_offset);
 243                memmove(input_buffer, input_buffer + input_offset, input_len);
 244                input_offset = 0;
 245        }
 246}
 247
 248/*
 249 * Make sure at least "min" bytes are available in the buffer, and
 250 * return the pointer to the buffer.
 251 */
 252static void *fill(int min)
 253{
 254        if (min <= input_len)
 255                return input_buffer + input_offset;
 256        if (min > sizeof(input_buffer))
 257                die(Q_("cannot fill %d byte",
 258                       "cannot fill %d bytes",
 259                       min),
 260                    min);
 261        flush();
 262        do {
 263                ssize_t ret = xread(input_fd, input_buffer + input_len,
 264                                sizeof(input_buffer) - input_len);
 265                if (ret <= 0) {
 266                        if (!ret)
 267                                die(_("early EOF"));
 268                        die_errno(_("read error on input"));
 269                }
 270                input_len += ret;
 271                if (from_stdin)
 272                        display_throughput(progress, consumed_bytes + input_len);
 273        } while (input_len < min);
 274        return input_buffer;
 275}
 276
 277static void use(int bytes)
 278{
 279        if (bytes > input_len)
 280                die(_("used more bytes than were available"));
 281        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 282        input_len -= bytes;
 283        input_offset += bytes;
 284
 285        /* make sure off_t is sufficiently large not to wrap */
 286        if (signed_add_overflows(consumed_bytes, bytes))
 287                die(_("pack too large for current definition of off_t"));
 288        consumed_bytes += bytes;
 289        if (max_input_size && consumed_bytes > max_input_size)
 290                die(_("pack exceeds maximum allowed size"));
 291}
 292
 293static const char *open_pack_file(const char *pack_name)
 294{
 295        if (from_stdin) {
 296                input_fd = 0;
 297                if (!pack_name) {
 298                        struct strbuf tmp_file = STRBUF_INIT;
 299                        output_fd = odb_mkstemp(&tmp_file,
 300                                                "pack/tmp_pack_XXXXXX");
 301                        pack_name = strbuf_detach(&tmp_file, NULL);
 302                } else {
 303                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 304                        if (output_fd < 0)
 305                                die_errno(_("unable to create '%s'"), pack_name);
 306                }
 307                nothread_data.pack_fd = output_fd;
 308        } else {
 309                input_fd = open(pack_name, O_RDONLY);
 310                if (input_fd < 0)
 311                        die_errno(_("cannot open packfile '%s'"), pack_name);
 312                output_fd = -1;
 313                nothread_data.pack_fd = input_fd;
 314        }
 315        the_hash_algo->init_fn(&input_ctx);
 316        return pack_name;
 317}
 318
 319static void parse_pack_header(void)
 320{
 321        struct pack_header *hdr = fill(sizeof(struct pack_header));
 322
 323        /* Header consistency check */
 324        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 325                die(_("pack signature mismatch"));
 326        if (!pack_version_ok(hdr->hdr_version))
 327                die(_("pack version %"PRIu32" unsupported"),
 328                        ntohl(hdr->hdr_version));
 329
 330        nr_objects = ntohl(hdr->hdr_entries);
 331        use(sizeof(struct pack_header));
 332}
 333
 334static NORETURN void bad_object(off_t offset, const char *format,
 335                       ...) __attribute__((format (printf, 2, 3)));
 336
 337static NORETURN void bad_object(off_t offset, const char *format, ...)
 338{
 339        va_list params;
 340        char buf[1024];
 341
 342        va_start(params, format);
 343        vsnprintf(buf, sizeof(buf), format, params);
 344        va_end(params);
 345        die(_("pack has bad object at offset %"PRIuMAX": %s"),
 346            (uintmax_t)offset, buf);
 347}
 348
 349static inline struct thread_local *get_thread_data(void)
 350{
 351        if (HAVE_THREADS) {
 352                if (threads_active)
 353                        return pthread_getspecific(key);
 354                assert(!threads_active &&
 355                       "This should only be reached when all threads are gone");
 356        }
 357        return &nothread_data;
 358}
 359
 360static void set_thread_data(struct thread_local *data)
 361{
 362        if (threads_active)
 363                pthread_setspecific(key, data);
 364}
 365
 366static struct base_data *alloc_base_data(void)
 367{
 368        struct base_data *base = xcalloc(1, sizeof(struct base_data));
 369        base->ref_last = -1;
 370        base->ofs_last = -1;
 371        return base;
 372}
 373
 374static void free_base_data(struct base_data *c)
 375{
 376        if (c->data) {
 377                FREE_AND_NULL(c->data);
 378                get_thread_data()->base_cache_used -= c->size;
 379        }
 380}
 381
 382static void prune_base_data(struct base_data *retain)
 383{
 384        struct base_data *b;
 385        struct thread_local *data = get_thread_data();
 386        for (b = data->base_cache;
 387             data->base_cache_used > delta_base_cache_limit && b;
 388             b = b->child) {
 389                if (b->data && b != retain)
 390                        free_base_data(b);
 391        }
 392}
 393
 394static void link_base_data(struct base_data *base, struct base_data *c)
 395{
 396        if (base)
 397                base->child = c;
 398        else
 399                get_thread_data()->base_cache = c;
 400
 401        c->base = base;
 402        c->child = NULL;
 403        if (c->data)
 404                get_thread_data()->base_cache_used += c->size;
 405        prune_base_data(c);
 406}
 407
 408static void unlink_base_data(struct base_data *c)
 409{
 410        struct base_data *base = c->base;
 411        if (base)
 412                base->child = NULL;
 413        else
 414                get_thread_data()->base_cache = NULL;
 415        free_base_data(c);
 416}
 417
 418static int is_delta_type(enum object_type type)
 419{
 420        return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 421}
 422
 423static void *unpack_entry_data(off_t offset, unsigned long size,
 424                               enum object_type type, struct object_id *oid)
 425{
 426        static char fixed_buf[8192];
 427        int status;
 428        git_zstream stream;
 429        void *buf;
 430        git_hash_ctx c;
 431        char hdr[32];
 432        int hdrlen;
 433
 434        if (!is_delta_type(type)) {
 435                hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX,
 436                                   type_name(type),(uintmax_t)size) + 1;
 437                the_hash_algo->init_fn(&c);
 438                the_hash_algo->update_fn(&c, hdr, hdrlen);
 439        } else
 440                oid = NULL;
 441        if (type == OBJ_BLOB && size > big_file_threshold)
 442                buf = fixed_buf;
 443        else
 444                buf = xmallocz(size);
 445
 446        memset(&stream, 0, sizeof(stream));
 447        git_inflate_init(&stream);
 448        stream.next_out = buf;
 449        stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 450
 451        do {
 452                unsigned char *last_out = stream.next_out;
 453                stream.next_in = fill(1);
 454                stream.avail_in = input_len;
 455                status = git_inflate(&stream, 0);
 456                use(input_len - stream.avail_in);
 457                if (oid)
 458                        the_hash_algo->update_fn(&c, last_out, stream.next_out - last_out);
 459                if (buf == fixed_buf) {
 460                        stream.next_out = buf;
 461                        stream.avail_out = sizeof(fixed_buf);
 462                }
 463        } while (status == Z_OK);
 464        if (stream.total_out != size || status != Z_STREAM_END)
 465                bad_object(offset, _("inflate returned %d"), status);
 466        git_inflate_end(&stream);
 467        if (oid)
 468                the_hash_algo->final_fn(oid->hash, &c);
 469        return buf == fixed_buf ? NULL : buf;
 470}
 471
 472static void *unpack_raw_entry(struct object_entry *obj,
 473                              off_t *ofs_offset,
 474                              struct object_id *ref_oid,
 475                              struct object_id *oid)
 476{
 477        unsigned char *p;
 478        unsigned long size, c;
 479        off_t base_offset;
 480        unsigned shift;
 481        void *data;
 482
 483        obj->idx.offset = consumed_bytes;
 484        input_crc32 = crc32(0, NULL, 0);
 485
 486        p = fill(1);
 487        c = *p;
 488        use(1);
 489        obj->type = (c >> 4) & 7;
 490        size = (c & 15);
 491        shift = 4;
 492        while (c & 0x80) {
 493                p = fill(1);
 494                c = *p;
 495                use(1);
 496                size += (c & 0x7f) << shift;
 497                shift += 7;
 498        }
 499        obj->size = size;
 500
 501        switch (obj->type) {
 502        case OBJ_REF_DELTA:
 503                hashcpy(ref_oid->hash, fill(the_hash_algo->rawsz));
 504                use(the_hash_algo->rawsz);
 505                break;
 506        case OBJ_OFS_DELTA:
 507                p = fill(1);
 508                c = *p;
 509                use(1);
 510                base_offset = c & 127;
 511                while (c & 128) {
 512                        base_offset += 1;
 513                        if (!base_offset || MSB(base_offset, 7))
 514                                bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 515                        p = fill(1);
 516                        c = *p;
 517                        use(1);
 518                        base_offset = (base_offset << 7) + (c & 127);
 519                }
 520                *ofs_offset = obj->idx.offset - base_offset;
 521                if (*ofs_offset <= 0 || *ofs_offset >= obj->idx.offset)
 522                        bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 523                break;
 524        case OBJ_COMMIT:
 525        case OBJ_TREE:
 526        case OBJ_BLOB:
 527        case OBJ_TAG:
 528                break;
 529        default:
 530                bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 531        }
 532        obj->hdr_size = consumed_bytes - obj->idx.offset;
 533
 534        data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, oid);
 535        obj->idx.crc32 = input_crc32;
 536        return data;
 537}
 538
 539static void *unpack_data(struct object_entry *obj,
 540                         int (*consume)(const unsigned char *, unsigned long, void *),
 541                         void *cb_data)
 542{
 543        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 544        off_t len = obj[1].idx.offset - from;
 545        unsigned char *data, *inbuf;
 546        git_zstream stream;
 547        int status;
 548
 549        data = xmallocz(consume ? 64*1024 : obj->size);
 550        inbuf = xmalloc((len < 64*1024) ? (int)len : 64*1024);
 551
 552        memset(&stream, 0, sizeof(stream));
 553        git_inflate_init(&stream);
 554        stream.next_out = data;
 555        stream.avail_out = consume ? 64*1024 : obj->size;
 556
 557        do {
 558                ssize_t n = (len < 64*1024) ? (ssize_t)len : 64*1024;
 559                n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 560                if (n < 0)
 561                        die_errno(_("cannot pread pack file"));
 562                if (!n)
 563                        die(Q_("premature end of pack file, %"PRIuMAX" byte missing",
 564                               "premature end of pack file, %"PRIuMAX" bytes missing",
 565                               (unsigned int)len),
 566                            (uintmax_t)len);
 567                from += n;
 568                len -= n;
 569                stream.next_in = inbuf;
 570                stream.avail_in = n;
 571                if (!consume)
 572                        status = git_inflate(&stream, 0);
 573                else {
 574                        do {
 575                                status = git_inflate(&stream, 0);
 576                                if (consume(data, stream.next_out - data, cb_data)) {
 577                                        free(inbuf);
 578                                        free(data);
 579                                        return NULL;
 580                                }
 581                                stream.next_out = data;
 582                                stream.avail_out = 64*1024;
 583                        } while (status == Z_OK && stream.avail_in);
 584                }
 585        } while (len && status == Z_OK && !stream.avail_in);
 586
 587        /* This has been inflated OK when first encountered, so... */
 588        if (status != Z_STREAM_END || stream.total_out != obj->size)
 589                die(_("serious inflate inconsistency"));
 590
 591        git_inflate_end(&stream);
 592        free(inbuf);
 593        if (consume) {
 594                FREE_AND_NULL(data);
 595        }
 596        return data;
 597}
 598
 599static void *get_data_from_pack(struct object_entry *obj)
 600{
 601        return unpack_data(obj, NULL, NULL);
 602}
 603
 604static int compare_ofs_delta_bases(off_t offset1, off_t offset2,
 605                                   enum object_type type1,
 606                                   enum object_type type2)
 607{
 608        int cmp = type1 - type2;
 609        if (cmp)
 610                return cmp;
 611        return offset1 < offset2 ? -1 :
 612               offset1 > offset2 ?  1 :
 613               0;
 614}
 615
 616static int find_ofs_delta(const off_t offset, enum object_type type)
 617{
 618        int first = 0, last = nr_ofs_deltas;
 619
 620        while (first < last) {
 621                int next = first + (last - first) / 2;
 622                struct ofs_delta_entry *delta = &ofs_deltas[next];
 623                int cmp;
 624
 625                cmp = compare_ofs_delta_bases(offset, delta->offset,
 626                                              type, objects[delta->obj_no].type);
 627                if (!cmp)
 628                        return next;
 629                if (cmp < 0) {
 630                        last = next;
 631                        continue;
 632                }
 633                first = next+1;
 634        }
 635        return -first-1;
 636}
 637
 638static void find_ofs_delta_children(off_t offset,
 639                                    int *first_index, int *last_index,
 640                                    enum object_type type)
 641{
 642        int first = find_ofs_delta(offset, type);
 643        int last = first;
 644        int end = nr_ofs_deltas - 1;
 645
 646        if (first < 0) {
 647                *first_index = 0;
 648                *last_index = -1;
 649                return;
 650        }
 651        while (first > 0 && ofs_deltas[first - 1].offset == offset)
 652                --first;
 653        while (last < end && ofs_deltas[last + 1].offset == offset)
 654                ++last;
 655        *first_index = first;
 656        *last_index = last;
 657}
 658
 659static int compare_ref_delta_bases(const struct object_id *oid1,
 660                                   const struct object_id *oid2,
 661                                   enum object_type type1,
 662                                   enum object_type type2)
 663{
 664        int cmp = type1 - type2;
 665        if (cmp)
 666                return cmp;
 667        return oidcmp(oid1, oid2);
 668}
 669
 670static int find_ref_delta(const struct object_id *oid, enum object_type type)
 671{
 672        int first = 0, last = nr_ref_deltas;
 673
 674        while (first < last) {
 675                int next = first + (last - first) / 2;
 676                struct ref_delta_entry *delta = &ref_deltas[next];
 677                int cmp;
 678
 679                cmp = compare_ref_delta_bases(oid, &delta->oid,
 680                                              type, objects[delta->obj_no].type);
 681                if (!cmp)
 682                        return next;
 683                if (cmp < 0) {
 684                        last = next;
 685                        continue;
 686                }
 687                first = next+1;
 688        }
 689        return -first-1;
 690}
 691
 692static void find_ref_delta_children(const struct object_id *oid,
 693                                    int *first_index, int *last_index,
 694                                    enum object_type type)
 695{
 696        int first = find_ref_delta(oid, type);
 697        int last = first;
 698        int end = nr_ref_deltas - 1;
 699
 700        if (first < 0) {
 701                *first_index = 0;
 702                *last_index = -1;
 703                return;
 704        }
 705        while (first > 0 && oideq(&ref_deltas[first - 1].oid, oid))
 706                --first;
 707        while (last < end && oideq(&ref_deltas[last + 1].oid, oid))
 708                ++last;
 709        *first_index = first;
 710        *last_index = last;
 711}
 712
 713struct compare_data {
 714        struct object_entry *entry;
 715        struct git_istream *st;
 716        unsigned char *buf;
 717        unsigned long buf_size;
 718};
 719
 720static int compare_objects(const unsigned char *buf, unsigned long size,
 721                           void *cb_data)
 722{
 723        struct compare_data *data = cb_data;
 724
 725        if (data->buf_size < size) {
 726                free(data->buf);
 727                data->buf = xmalloc(size);
 728                data->buf_size = size;
 729        }
 730
 731        while (size) {
 732                ssize_t len = read_istream(data->st, data->buf, size);
 733                if (len == 0)
 734                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 735                            oid_to_hex(&data->entry->idx.oid));
 736                if (len < 0)
 737                        die(_("unable to read %s"),
 738                            oid_to_hex(&data->entry->idx.oid));
 739                if (memcmp(buf, data->buf, len))
 740                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 741                            oid_to_hex(&data->entry->idx.oid));
 742                size -= len;
 743                buf += len;
 744        }
 745        return 0;
 746}
 747
 748static int check_collison(struct object_entry *entry)
 749{
 750        struct compare_data data;
 751        enum object_type type;
 752        unsigned long size;
 753
 754        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 755                return -1;
 756
 757        memset(&data, 0, sizeof(data));
 758        data.entry = entry;
 759        data.st = open_istream(&entry->idx.oid, &type, &size, NULL);
 760        if (!data.st)
 761                return -1;
 762        if (size != entry->size || type != entry->type)
 763                die(_("SHA1 COLLISION FOUND WITH %s !"),
 764                    oid_to_hex(&entry->idx.oid));
 765        unpack_data(entry, compare_objects, &data);
 766        close_istream(data.st);
 767        free(data.buf);
 768        return 0;
 769}
 770
 771static void sha1_object(const void *data, struct object_entry *obj_entry,
 772                        unsigned long size, enum object_type type,
 773                        const struct object_id *oid)
 774{
 775        void *new_data = NULL;
 776        int collision_test_needed = 0;
 777
 778        assert(data || obj_entry);
 779
 780        if (startup_info->have_repository) {
 781                read_lock();
 782                collision_test_needed =
 783                        has_object_file_with_flags(oid, OBJECT_INFO_QUICK);
 784                read_unlock();
 785        }
 786
 787        if (collision_test_needed && !data) {
 788                read_lock();
 789                if (!check_collison(obj_entry))
 790                        collision_test_needed = 0;
 791                read_unlock();
 792        }
 793        if (collision_test_needed) {
 794                void *has_data;
 795                enum object_type has_type;
 796                unsigned long has_size;
 797                read_lock();
 798                has_type = oid_object_info(the_repository, oid, &has_size);
 799                if (has_type < 0)
 800                        die(_("cannot read existing object info %s"), oid_to_hex(oid));
 801                if (has_type != type || has_size != size)
 802                        die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 803                has_data = read_object_file(oid, &has_type, &has_size);
 804                read_unlock();
 805                if (!data)
 806                        data = new_data = get_data_from_pack(obj_entry);
 807                if (!has_data)
 808                        die(_("cannot read existing object %s"), oid_to_hex(oid));
 809                if (size != has_size || type != has_type ||
 810                    memcmp(data, has_data, size) != 0)
 811                        die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 812                free(has_data);
 813        }
 814
 815        if (strict || do_fsck_object) {
 816                read_lock();
 817                if (type == OBJ_BLOB) {
 818                        struct blob *blob = lookup_blob(the_repository, oid);
 819                        if (blob)
 820                                blob->object.flags |= FLAG_CHECKED;
 821                        else
 822                                die(_("invalid blob object %s"), oid_to_hex(oid));
 823                        if (do_fsck_object &&
 824                            fsck_object(&blob->object, (void *)data, size, &fsck_options))
 825                                die(_("fsck error in packed object"));
 826                } else {
 827                        struct object *obj;
 828                        int eaten;
 829                        void *buf = (void *) data;
 830
 831                        assert(data && "data can only be NULL for large _blobs_");
 832
 833                        /*
 834                         * we do not need to free the memory here, as the
 835                         * buf is deleted by the caller.
 836                         */
 837                        obj = parse_object_buffer(the_repository, oid, type,
 838                                                  size, buf,
 839                                                  &eaten);
 840                        if (!obj)
 841                                die(_("invalid %s"), type_name(type));
 842                        if (do_fsck_object &&
 843                            fsck_object(obj, buf, size, &fsck_options))
 844                                die(_("fsck error in packed object"));
 845                        if (strict && fsck_walk(obj, NULL, &fsck_options))
 846                                die(_("Not all child objects of %s are reachable"), oid_to_hex(&obj->oid));
 847
 848                        if (obj->type == OBJ_TREE) {
 849                                struct tree *item = (struct tree *) obj;
 850                                item->buffer = NULL;
 851                                obj->parsed = 0;
 852                        }
 853                        if (obj->type == OBJ_COMMIT) {
 854                                struct commit *commit = (struct commit *) obj;
 855                                if (detach_commit_buffer(commit, NULL) != data)
 856                                        BUG("parse_object_buffer transmogrified our buffer");
 857                        }
 858                        obj->flags |= FLAG_CHECKED;
 859                }
 860                read_unlock();
 861        }
 862
 863        free(new_data);
 864}
 865
 866/*
 867 * This function is part of find_unresolved_deltas(). There are two
 868 * walkers going in the opposite ways.
 869 *
 870 * The first one in find_unresolved_deltas() traverses down from
 871 * parent node to children, deflating nodes along the way. However,
 872 * memory for deflated nodes is limited by delta_base_cache_limit, so
 873 * at some point parent node's deflated content may be freed.
 874 *
 875 * The second walker is this function, which goes from current node up
 876 * to top parent if necessary to deflate the node. In normal
 877 * situation, its parent node would be already deflated, so it just
 878 * needs to apply delta.
 879 *
 880 * In the worst case scenario, parent node is no longer deflated because
 881 * we're running out of delta_base_cache_limit; we need to re-deflate
 882 * parents, possibly up to the top base.
 883 *
 884 * All deflated objects here are subject to be freed if we exceed
 885 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 886 * just need to make sure the last node is not freed.
 887 */
 888static void *get_base_data(struct base_data *c)
 889{
 890        if (!c->data) {
 891                struct object_entry *obj = c->obj;
 892                struct base_data **delta = NULL;
 893                int delta_nr = 0, delta_alloc = 0;
 894
 895                while (is_delta_type(c->obj->type) && !c->data) {
 896                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 897                        delta[delta_nr++] = c;
 898                        c = c->base;
 899                }
 900                if (!delta_nr) {
 901                        c->data = get_data_from_pack(obj);
 902                        c->size = obj->size;
 903                        get_thread_data()->base_cache_used += c->size;
 904                        prune_base_data(c);
 905                }
 906                for (; delta_nr > 0; delta_nr--) {
 907                        void *base, *raw;
 908                        c = delta[delta_nr - 1];
 909                        obj = c->obj;
 910                        base = get_base_data(c->base);
 911                        raw = get_data_from_pack(obj);
 912                        c->data = patch_delta(
 913                                base, c->base->size,
 914                                raw, obj->size,
 915                                &c->size);
 916                        free(raw);
 917                        if (!c->data)
 918                                bad_object(obj->idx.offset, _("failed to apply delta"));
 919                        get_thread_data()->base_cache_used += c->size;
 920                        prune_base_data(c);
 921                }
 922                free(delta);
 923        }
 924        return c->data;
 925}
 926
 927static void resolve_delta(struct object_entry *delta_obj,
 928                          struct base_data *base, struct base_data *result)
 929{
 930        void *base_data, *delta_data;
 931
 932        if (show_stat) {
 933                int i = delta_obj - objects;
 934                int j = base->obj - objects;
 935                obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 936                deepest_delta_lock();
 937                if (deepest_delta < obj_stat[i].delta_depth)
 938                        deepest_delta = obj_stat[i].delta_depth;
 939                deepest_delta_unlock();
 940                obj_stat[i].base_object_no = j;
 941        }
 942        delta_data = get_data_from_pack(delta_obj);
 943        base_data = get_base_data(base);
 944        result->obj = delta_obj;
 945        result->data = patch_delta(base_data, base->size,
 946                                   delta_data, delta_obj->size, &result->size);
 947        free(delta_data);
 948        if (!result->data)
 949                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 950        hash_object_file(result->data, result->size,
 951                         type_name(delta_obj->real_type), &delta_obj->idx.oid);
 952        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 953                    &delta_obj->idx.oid);
 954        counter_lock();
 955        nr_resolved_deltas++;
 956        counter_unlock();
 957}
 958
 959/*
 960 * Standard boolean compare-and-swap: atomically check whether "*type" is
 961 * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 962 * and return false.
 963 */
 964static int compare_and_swap_type(signed char *type,
 965                                 enum object_type want,
 966                                 enum object_type set)
 967{
 968        enum object_type old;
 969
 970        type_cas_lock();
 971        old = *type;
 972        if (old == want)
 973                *type = set;
 974        type_cas_unlock();
 975
 976        return old == want;
 977}
 978
 979static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 980                                                  struct base_data *prev_base)
 981{
 982        if (base->ref_last == -1 && base->ofs_last == -1) {
 983                find_ref_delta_children(&base->obj->idx.oid,
 984                                        &base->ref_first, &base->ref_last,
 985                                        OBJ_REF_DELTA);
 986
 987                find_ofs_delta_children(base->obj->idx.offset,
 988                                        &base->ofs_first, &base->ofs_last,
 989                                        OBJ_OFS_DELTA);
 990
 991                if (base->ref_last == -1 && base->ofs_last == -1) {
 992                        free(base->data);
 993                        return NULL;
 994                }
 995
 996                link_base_data(prev_base, base);
 997        }
 998
 999        if (base->ref_first <= base->ref_last) {
1000                struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
1001                struct base_data *result = alloc_base_data();
1002
1003                if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
1004                                           base->obj->real_type))
1005                        BUG("child->real_type != OBJ_REF_DELTA");
1006
1007                resolve_delta(child, base, result);
1008                if (base->ref_first == base->ref_last && base->ofs_last == -1)
1009                        free_base_data(base);
1010
1011                base->ref_first++;
1012                return result;
1013        }
1014
1015        if (base->ofs_first <= base->ofs_last) {
1016                struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
1017                struct base_data *result = alloc_base_data();
1018
1019                assert(child->real_type == OBJ_OFS_DELTA);
1020                child->real_type = base->obj->real_type;
1021                resolve_delta(child, base, result);
1022                if (base->ofs_first == base->ofs_last)
1023                        free_base_data(base);
1024
1025                base->ofs_first++;
1026                return result;
1027        }
1028
1029        unlink_base_data(base);
1030        return NULL;
1031}
1032
1033static void find_unresolved_deltas(struct base_data *base)
1034{
1035        struct base_data *new_base, *prev_base = NULL;
1036        for (;;) {
1037                new_base = find_unresolved_deltas_1(base, prev_base);
1038
1039                if (new_base) {
1040                        prev_base = base;
1041                        base = new_base;
1042                } else {
1043                        free(base);
1044                        base = prev_base;
1045                        if (!base)
1046                                return;
1047                        prev_base = base->base;
1048                }
1049        }
1050}
1051
1052static int compare_ofs_delta_entry(const void *a, const void *b)
1053{
1054        const struct ofs_delta_entry *delta_a = a;
1055        const struct ofs_delta_entry *delta_b = b;
1056
1057        return delta_a->offset < delta_b->offset ? -1 :
1058               delta_a->offset > delta_b->offset ?  1 :
1059               0;
1060}
1061
1062static int compare_ref_delta_entry(const void *a, const void *b)
1063{
1064        const struct ref_delta_entry *delta_a = a;
1065        const struct ref_delta_entry *delta_b = b;
1066
1067        return oidcmp(&delta_a->oid, &delta_b->oid);
1068}
1069
1070static void resolve_base(struct object_entry *obj)
1071{
1072        struct base_data *base_obj = alloc_base_data();
1073        base_obj->obj = obj;
1074        base_obj->data = NULL;
1075        find_unresolved_deltas(base_obj);
1076}
1077
1078static void *threaded_second_pass(void *data)
1079{
1080        set_thread_data(data);
1081        for (;;) {
1082                int i;
1083                counter_lock();
1084                display_progress(progress, nr_resolved_deltas);
1085                counter_unlock();
1086                work_lock();
1087                while (nr_dispatched < nr_objects &&
1088                       is_delta_type(objects[nr_dispatched].type))
1089                        nr_dispatched++;
1090                if (nr_dispatched >= nr_objects) {
1091                        work_unlock();
1092                        break;
1093                }
1094                i = nr_dispatched++;
1095                work_unlock();
1096
1097                resolve_base(&objects[i]);
1098        }
1099        return NULL;
1100}
1101
1102/*
1103 * First pass:
1104 * - find locations of all objects;
1105 * - calculate SHA1 of all non-delta objects;
1106 * - remember base (SHA1 or offset) for all deltas.
1107 */
1108static void parse_pack_objects(unsigned char *hash)
1109{
1110        int i, nr_delays = 0;
1111        struct ofs_delta_entry *ofs_delta = ofs_deltas;
1112        struct object_id ref_delta_oid;
1113        struct stat st;
1114
1115        if (verbose)
1116                progress = start_progress(
1117                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1118                                nr_objects);
1119        for (i = 0; i < nr_objects; i++) {
1120                struct object_entry *obj = &objects[i];
1121                void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1122                                              &ref_delta_oid,
1123                                              &obj->idx.oid);
1124                obj->real_type = obj->type;
1125                if (obj->type == OBJ_OFS_DELTA) {
1126                        nr_ofs_deltas++;
1127                        ofs_delta->obj_no = i;
1128                        ofs_delta++;
1129                } else if (obj->type == OBJ_REF_DELTA) {
1130                        ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1131                        oidcpy(&ref_deltas[nr_ref_deltas].oid, &ref_delta_oid);
1132                        ref_deltas[nr_ref_deltas].obj_no = i;
1133                        nr_ref_deltas++;
1134                } else if (!data) {
1135                        /* large blobs, check later */
1136                        obj->real_type = OBJ_BAD;
1137                        nr_delays++;
1138                } else
1139                        sha1_object(data, NULL, obj->size, obj->type,
1140                                    &obj->idx.oid);
1141                free(data);
1142                display_progress(progress, i+1);
1143        }
1144        objects[i].idx.offset = consumed_bytes;
1145        stop_progress(&progress);
1146
1147        /* Check pack integrity */
1148        flush();
1149        the_hash_algo->final_fn(hash, &input_ctx);
1150        if (!hasheq(fill(the_hash_algo->rawsz), hash))
1151                die(_("pack is corrupted (SHA1 mismatch)"));
1152        use(the_hash_algo->rawsz);
1153
1154        /* If input_fd is a file, we should have reached its end now. */
1155        if (fstat(input_fd, &st))
1156                die_errno(_("cannot fstat packfile"));
1157        if (S_ISREG(st.st_mode) &&
1158                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1159                die(_("pack has junk at the end"));
1160
1161        for (i = 0; i < nr_objects; i++) {
1162                struct object_entry *obj = &objects[i];
1163                if (obj->real_type != OBJ_BAD)
1164                        continue;
1165                obj->real_type = obj->type;
1166                sha1_object(NULL, obj, obj->size, obj->type,
1167                            &obj->idx.oid);
1168                nr_delays--;
1169        }
1170        if (nr_delays)
1171                die(_("confusion beyond insanity in parse_pack_objects()"));
1172}
1173
1174/*
1175 * Second pass:
1176 * - for all non-delta objects, look if it is used as a base for
1177 *   deltas;
1178 * - if used as a base, uncompress the object and apply all deltas,
1179 *   recursively checking if the resulting object is used as a base
1180 *   for some more deltas.
1181 */
1182static void resolve_deltas(void)
1183{
1184        int i;
1185
1186        if (!nr_ofs_deltas && !nr_ref_deltas)
1187                return;
1188
1189        /* Sort deltas by base SHA1/offset for fast searching */
1190        QSORT(ofs_deltas, nr_ofs_deltas, compare_ofs_delta_entry);
1191        QSORT(ref_deltas, nr_ref_deltas, compare_ref_delta_entry);
1192
1193        if (verbose || show_resolving_progress)
1194                progress = start_progress(_("Resolving deltas"),
1195                                          nr_ref_deltas + nr_ofs_deltas);
1196
1197        nr_dispatched = 0;
1198        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1199                init_thread();
1200                for (i = 0; i < nr_threads; i++) {
1201                        int ret = pthread_create(&thread_data[i].thread, NULL,
1202                                                 threaded_second_pass, thread_data + i);
1203                        if (ret)
1204                                die(_("unable to create thread: %s"),
1205                                    strerror(ret));
1206                }
1207                for (i = 0; i < nr_threads; i++)
1208                        pthread_join(thread_data[i].thread, NULL);
1209                cleanup_thread();
1210                return;
1211        }
1212
1213        for (i = 0; i < nr_objects; i++) {
1214                struct object_entry *obj = &objects[i];
1215
1216                if (is_delta_type(obj->type))
1217                        continue;
1218                resolve_base(obj);
1219                display_progress(progress, nr_resolved_deltas);
1220        }
1221}
1222
1223/*
1224 * Third pass:
1225 * - append objects to convert thin pack to full pack if required
1226 * - write the final pack hash
1227 */
1228static void fix_unresolved_deltas(struct hashfile *f);
1229static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_hash)
1230{
1231        if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1232                stop_progress(&progress);
1233                /* Flush remaining pack final hash. */
1234                flush();
1235                return;
1236        }
1237
1238        if (fix_thin_pack) {
1239                struct hashfile *f;
1240                unsigned char read_hash[GIT_MAX_RAWSZ], tail_hash[GIT_MAX_RAWSZ];
1241                struct strbuf msg = STRBUF_INIT;
1242                int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1243                int nr_objects_initial = nr_objects;
1244                if (nr_unresolved <= 0)
1245                        die(_("confusion beyond insanity"));
1246                REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1247                memset(objects + nr_objects + 1, 0,
1248                       nr_unresolved * sizeof(*objects));
1249                f = hashfd(output_fd, curr_pack);
1250                fix_unresolved_deltas(f);
1251                strbuf_addf(&msg, Q_("completed with %d local object",
1252                                     "completed with %d local objects",
1253                                     nr_objects - nr_objects_initial),
1254                            nr_objects - nr_objects_initial);
1255                stop_progress_msg(&progress, msg.buf);
1256                strbuf_release(&msg);
1257                finalize_hashfile(f, tail_hash, 0);
1258                hashcpy(read_hash, pack_hash);
1259                fixup_pack_header_footer(output_fd, pack_hash,
1260                                         curr_pack, nr_objects,
1261                                         read_hash, consumed_bytes-the_hash_algo->rawsz);
1262                if (!hasheq(read_hash, tail_hash))
1263                        die(_("Unexpected tail checksum for %s "
1264                              "(disk corruption?)"), curr_pack);
1265        }
1266        if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1267                die(Q_("pack has %d unresolved delta",
1268                       "pack has %d unresolved deltas",
1269                       nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1270                    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1271}
1272
1273static int write_compressed(struct hashfile *f, void *in, unsigned int size)
1274{
1275        git_zstream stream;
1276        int status;
1277        unsigned char outbuf[4096];
1278
1279        git_deflate_init(&stream, zlib_compression_level);
1280        stream.next_in = in;
1281        stream.avail_in = size;
1282
1283        do {
1284                stream.next_out = outbuf;
1285                stream.avail_out = sizeof(outbuf);
1286                status = git_deflate(&stream, Z_FINISH);
1287                hashwrite(f, outbuf, sizeof(outbuf) - stream.avail_out);
1288        } while (status == Z_OK);
1289
1290        if (status != Z_STREAM_END)
1291                die(_("unable to deflate appended object (%d)"), status);
1292        size = stream.total_out;
1293        git_deflate_end(&stream);
1294        return size;
1295}
1296
1297static struct object_entry *append_obj_to_pack(struct hashfile *f,
1298                               const unsigned char *sha1, void *buf,
1299                               unsigned long size, enum object_type type)
1300{
1301        struct object_entry *obj = &objects[nr_objects++];
1302        unsigned char header[10];
1303        unsigned long s = size;
1304        int n = 0;
1305        unsigned char c = (type << 4) | (s & 15);
1306        s >>= 4;
1307        while (s) {
1308                header[n++] = c | 0x80;
1309                c = s & 0x7f;
1310                s >>= 7;
1311        }
1312        header[n++] = c;
1313        crc32_begin(f);
1314        hashwrite(f, header, n);
1315        obj[0].size = size;
1316        obj[0].hdr_size = n;
1317        obj[0].type = type;
1318        obj[0].real_type = type;
1319        obj[1].idx.offset = obj[0].idx.offset + n;
1320        obj[1].idx.offset += write_compressed(f, buf, size);
1321        obj[0].idx.crc32 = crc32_end(f);
1322        hashflush(f);
1323        hashcpy(obj->idx.oid.hash, sha1);
1324        return obj;
1325}
1326
1327static int delta_pos_compare(const void *_a, const void *_b)
1328{
1329        struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1330        struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1331        return a->obj_no - b->obj_no;
1332}
1333
1334static void fix_unresolved_deltas(struct hashfile *f)
1335{
1336        struct ref_delta_entry **sorted_by_pos;
1337        int i;
1338
1339        /*
1340         * Since many unresolved deltas may well be themselves base objects
1341         * for more unresolved deltas, we really want to include the
1342         * smallest number of base objects that would cover as much delta
1343         * as possible by picking the
1344         * trunc deltas first, allowing for other deltas to resolve without
1345         * additional base objects.  Since most base objects are to be found
1346         * before deltas depending on them, a good heuristic is to start
1347         * resolving deltas in the same order as their position in the pack.
1348         */
1349        ALLOC_ARRAY(sorted_by_pos, nr_ref_deltas);
1350        for (i = 0; i < nr_ref_deltas; i++)
1351                sorted_by_pos[i] = &ref_deltas[i];
1352        QSORT(sorted_by_pos, nr_ref_deltas, delta_pos_compare);
1353
1354        for (i = 0; i < nr_ref_deltas; i++) {
1355                struct ref_delta_entry *d = sorted_by_pos[i];
1356                enum object_type type;
1357                struct base_data *base_obj = alloc_base_data();
1358
1359                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1360                        continue;
1361                base_obj->data = read_object_file(&d->oid, &type,
1362                                                  &base_obj->size);
1363                if (!base_obj->data)
1364                        continue;
1365
1366                if (check_object_signature(&d->oid, base_obj->data,
1367                                base_obj->size, type_name(type)))
1368                        die(_("local object %s is corrupt"), oid_to_hex(&d->oid));
1369                base_obj->obj = append_obj_to_pack(f, d->oid.hash,
1370                                        base_obj->data, base_obj->size, type);
1371                find_unresolved_deltas(base_obj);
1372                display_progress(progress, nr_resolved_deltas);
1373        }
1374        free(sorted_by_pos);
1375}
1376
1377static const char *derive_filename(const char *pack_name, const char *suffix,
1378                                   struct strbuf *buf)
1379{
1380        size_t len;
1381        if (!strip_suffix(pack_name, ".pack", &len))
1382                die(_("packfile name '%s' does not end with '.pack'"),
1383                    pack_name);
1384        strbuf_add(buf, pack_name, len);
1385        strbuf_addch(buf, '.');
1386        strbuf_addstr(buf, suffix);
1387        return buf->buf;
1388}
1389
1390static void write_special_file(const char *suffix, const char *msg,
1391                               const char *pack_name, const unsigned char *hash,
1392                               const char **report)
1393{
1394        struct strbuf name_buf = STRBUF_INIT;
1395        const char *filename;
1396        int fd;
1397        int msg_len = strlen(msg);
1398
1399        if (pack_name)
1400                filename = derive_filename(pack_name, suffix, &name_buf);
1401        else
1402                filename = odb_pack_name(&name_buf, hash, suffix);
1403
1404        fd = odb_pack_keep(filename);
1405        if (fd < 0) {
1406                if (errno != EEXIST)
1407                        die_errno(_("cannot write %s file '%s'"),
1408                                  suffix, filename);
1409        } else {
1410                if (msg_len > 0) {
1411                        write_or_die(fd, msg, msg_len);
1412                        write_or_die(fd, "\n", 1);
1413                }
1414                if (close(fd) != 0)
1415                        die_errno(_("cannot close written %s file '%s'"),
1416                                  suffix, filename);
1417                if (report)
1418                        *report = suffix;
1419        }
1420        strbuf_release(&name_buf);
1421}
1422
1423static void final(const char *final_pack_name, const char *curr_pack_name,
1424                  const char *final_index_name, const char *curr_index_name,
1425                  const char *keep_msg, const char *promisor_msg,
1426                  unsigned char *hash)
1427{
1428        const char *report = "pack";
1429        struct strbuf pack_name = STRBUF_INIT;
1430        struct strbuf index_name = STRBUF_INIT;
1431        int err;
1432
1433        if (!from_stdin) {
1434                close(input_fd);
1435        } else {
1436                fsync_or_die(output_fd, curr_pack_name);
1437                err = close(output_fd);
1438                if (err)
1439                        die_errno(_("error while closing pack file"));
1440        }
1441
1442        if (keep_msg)
1443                write_special_file("keep", keep_msg, final_pack_name, hash,
1444                                   &report);
1445        if (promisor_msg)
1446                write_special_file("promisor", promisor_msg, final_pack_name,
1447                                   hash, NULL);
1448
1449        if (final_pack_name != curr_pack_name) {
1450                if (!final_pack_name)
1451                        final_pack_name = odb_pack_name(&pack_name, hash, "pack");
1452                if (finalize_object_file(curr_pack_name, final_pack_name))
1453                        die(_("cannot store pack file"));
1454        } else if (from_stdin)
1455                chmod(final_pack_name, 0444);
1456
1457        if (final_index_name != curr_index_name) {
1458                if (!final_index_name)
1459                        final_index_name = odb_pack_name(&index_name, hash, "idx");
1460                if (finalize_object_file(curr_index_name, final_index_name))
1461                        die(_("cannot store index file"));
1462        } else
1463                chmod(final_index_name, 0444);
1464
1465        if (do_fsck_object) {
1466                struct packed_git *p;
1467                p = add_packed_git(final_index_name, strlen(final_index_name), 0);
1468                if (p)
1469                        install_packed_git(the_repository, p);
1470        }
1471
1472        if (!from_stdin) {
1473                printf("%s\n", sha1_to_hex(hash));
1474        } else {
1475                struct strbuf buf = STRBUF_INIT;
1476
1477                strbuf_addf(&buf, "%s\t%s\n", report, sha1_to_hex(hash));
1478                write_or_die(1, buf.buf, buf.len);
1479                strbuf_release(&buf);
1480
1481                /*
1482                 * Let's just mimic git-unpack-objects here and write
1483                 * the last part of the input buffer to stdout.
1484                 */
1485                while (input_len) {
1486                        err = xwrite(1, input_buffer + input_offset, input_len);
1487                        if (err <= 0)
1488                                break;
1489                        input_len -= err;
1490                        input_offset += err;
1491                }
1492        }
1493
1494        strbuf_release(&index_name);
1495        strbuf_release(&pack_name);
1496}
1497
1498static int git_index_pack_config(const char *k, const char *v, void *cb)
1499{
1500        struct pack_idx_option *opts = cb;
1501
1502        if (!strcmp(k, "pack.indexversion")) {
1503                opts->version = git_config_int(k, v);
1504                if (opts->version > 2)
1505                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1506                return 0;
1507        }
1508        if (!strcmp(k, "pack.threads")) {
1509                nr_threads = git_config_int(k, v);
1510                if (nr_threads < 0)
1511                        die(_("invalid number of threads specified (%d)"),
1512                            nr_threads);
1513                if (!HAVE_THREADS && nr_threads != 1) {
1514                        warning(_("no threads support, ignoring %s"), k);
1515                        nr_threads = 1;
1516                }
1517                return 0;
1518        }
1519        return git_default_config(k, v, cb);
1520}
1521
1522static int cmp_uint32(const void *a_, const void *b_)
1523{
1524        uint32_t a = *((uint32_t *)a_);
1525        uint32_t b = *((uint32_t *)b_);
1526
1527        return (a < b) ? -1 : (a != b);
1528}
1529
1530static void read_v2_anomalous_offsets(struct packed_git *p,
1531                                      struct pack_idx_option *opts)
1532{
1533        const uint32_t *idx1, *idx2;
1534        uint32_t i;
1535        const uint32_t hashwords = the_hash_algo->rawsz / sizeof(uint32_t);
1536
1537        /* The address of the 4-byte offset table */
1538        idx1 = (((const uint32_t *)p->index_data)
1539                + 2 /* 8-byte header */
1540                + 256 /* fan out */
1541                + hashwords * p->num_objects /* object ID table */
1542                + p->num_objects /* CRC32 table */
1543                );
1544
1545        /* The address of the 8-byte offset table */
1546        idx2 = idx1 + p->num_objects;
1547
1548        for (i = 0; i < p->num_objects; i++) {
1549                uint32_t off = ntohl(idx1[i]);
1550                if (!(off & 0x80000000))
1551                        continue;
1552                off = off & 0x7fffffff;
1553                check_pack_index_ptr(p, &idx2[off * 2]);
1554                if (idx2[off * 2])
1555                        continue;
1556                /*
1557                 * The real offset is ntohl(idx2[off * 2]) in high 4
1558                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1559                 * octets.  But idx2[off * 2] is Zero!!!
1560                 */
1561                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1562                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1563        }
1564
1565        QSORT(opts->anomaly, opts->anomaly_nr, cmp_uint32);
1566}
1567
1568static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1569{
1570        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1571
1572        if (!p)
1573                die(_("Cannot open existing pack file '%s'"), pack_name);
1574        if (open_pack_index(p))
1575                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1576
1577        /* Read the attributes from the existing idx file */
1578        opts->version = p->index_version;
1579
1580        if (opts->version == 2)
1581                read_v2_anomalous_offsets(p, opts);
1582
1583        /*
1584         * Get rid of the idx file as we do not need it anymore.
1585         * NEEDSWORK: extract this bit from free_pack_by_name() in
1586         * sha1-file.c, perhaps?  It shouldn't matter very much as we
1587         * know we haven't installed this pack (hence we never have
1588         * read anything from it).
1589         */
1590        close_pack_index(p);
1591        free(p);
1592}
1593
1594static void show_pack_info(int stat_only)
1595{
1596        int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1597        unsigned long *chain_histogram = NULL;
1598
1599        if (deepest_delta)
1600                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1601
1602        for (i = 0; i < nr_objects; i++) {
1603                struct object_entry *obj = &objects[i];
1604
1605                if (is_delta_type(obj->type))
1606                        chain_histogram[obj_stat[i].delta_depth - 1]++;
1607                if (stat_only)
1608                        continue;
1609                printf("%s %-6s %"PRIuMAX" %"PRIuMAX" %"PRIuMAX,
1610                       oid_to_hex(&obj->idx.oid),
1611                       type_name(obj->real_type), (uintmax_t)obj->size,
1612                       (uintmax_t)(obj[1].idx.offset - obj->idx.offset),
1613                       (uintmax_t)obj->idx.offset);
1614                if (is_delta_type(obj->type)) {
1615                        struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1616                        printf(" %u %s", obj_stat[i].delta_depth,
1617                               oid_to_hex(&bobj->idx.oid));
1618                }
1619                putchar('\n');
1620        }
1621
1622        if (baseobjects)
1623                printf_ln(Q_("non delta: %d object",
1624                             "non delta: %d objects",
1625                             baseobjects),
1626                          baseobjects);
1627        for (i = 0; i < deepest_delta; i++) {
1628                if (!chain_histogram[i])
1629                        continue;
1630                printf_ln(Q_("chain length = %d: %lu object",
1631                             "chain length = %d: %lu objects",
1632                             chain_histogram[i]),
1633                          i + 1,
1634                          chain_histogram[i]);
1635        }
1636}
1637
1638int cmd_index_pack(int argc, const char **argv, const char *prefix)
1639{
1640        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1641        const char *curr_index;
1642        const char *index_name = NULL, *pack_name = NULL;
1643        const char *keep_msg = NULL;
1644        const char *promisor_msg = NULL;
1645        struct strbuf index_name_buf = STRBUF_INIT;
1646        struct pack_idx_entry **idx_objects;
1647        struct pack_idx_option opts;
1648        unsigned char pack_hash[GIT_MAX_RAWSZ];
1649        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1650        int report_end_of_input = 0;
1651
1652        /*
1653         * index-pack never needs to fetch missing objects, since it only
1654         * accesses the repo to do hash collision checks
1655         */
1656        fetch_if_missing = 0;
1657
1658        if (argc == 2 && !strcmp(argv[1], "-h"))
1659                usage(index_pack_usage);
1660
1661        read_replace_refs = 0;
1662        fsck_options.walk = mark_link;
1663
1664        reset_pack_idx_option(&opts);
1665        git_config(git_index_pack_config, &opts);
1666        if (prefix && chdir(prefix))
1667                die(_("Cannot come back to cwd"));
1668
1669        for (i = 1; i < argc; i++) {
1670                const char *arg = argv[i];
1671
1672                if (*arg == '-') {
1673                        if (!strcmp(arg, "--stdin")) {
1674                                from_stdin = 1;
1675                        } else if (!strcmp(arg, "--fix-thin")) {
1676                                fix_thin_pack = 1;
1677                        } else if (skip_to_optional_arg(arg, "--strict", &arg)) {
1678                                strict = 1;
1679                                do_fsck_object = 1;
1680                                fsck_set_msg_types(&fsck_options, arg);
1681                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1682                                strict = 1;
1683                                check_self_contained_and_connected = 1;
1684                        } else if (!strcmp(arg, "--fsck-objects")) {
1685                                do_fsck_object = 1;
1686                        } else if (!strcmp(arg, "--verify")) {
1687                                verify = 1;
1688                        } else if (!strcmp(arg, "--verify-stat")) {
1689                                verify = 1;
1690                                show_stat = 1;
1691                        } else if (!strcmp(arg, "--verify-stat-only")) {
1692                                verify = 1;
1693                                show_stat = 1;
1694                                stat_only = 1;
1695                        } else if (skip_to_optional_arg(arg, "--keep", &keep_msg)) {
1696                                ; /* nothing to do */
1697                        } else if (skip_to_optional_arg(arg, "--promisor", &promisor_msg)) {
1698                                ; /* already parsed */
1699                        } else if (starts_with(arg, "--threads=")) {
1700                                char *end;
1701                                nr_threads = strtoul(arg+10, &end, 0);
1702                                if (!arg[10] || *end || nr_threads < 0)
1703                                        usage(index_pack_usage);
1704                                if (!HAVE_THREADS && nr_threads != 1) {
1705                                        warning(_("no threads support, ignoring %s"), arg);
1706                                        nr_threads = 1;
1707                                }
1708                        } else if (starts_with(arg, "--pack_header=")) {
1709                                struct pack_header *hdr;
1710                                char *c;
1711
1712                                hdr = (struct pack_header *)input_buffer;
1713                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1714                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1715                                if (*c != ',')
1716                                        die(_("bad %s"), arg);
1717                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1718                                if (*c)
1719                                        die(_("bad %s"), arg);
1720                                input_len = sizeof(*hdr);
1721                        } else if (!strcmp(arg, "-v")) {
1722                                verbose = 1;
1723                        } else if (!strcmp(arg, "--show-resolving-progress")) {
1724                                show_resolving_progress = 1;
1725                        } else if (!strcmp(arg, "--report-end-of-input")) {
1726                                report_end_of_input = 1;
1727                        } else if (!strcmp(arg, "-o")) {
1728                                if (index_name || (i+1) >= argc)
1729                                        usage(index_pack_usage);
1730                                index_name = argv[++i];
1731                        } else if (starts_with(arg, "--index-version=")) {
1732                                char *c;
1733                                opts.version = strtoul(arg + 16, &c, 10);
1734                                if (opts.version > 2)
1735                                        die(_("bad %s"), arg);
1736                                if (*c == ',')
1737                                        opts.off32_limit = strtoul(c+1, &c, 0);
1738                                if (*c || opts.off32_limit & 0x80000000)
1739                                        die(_("bad %s"), arg);
1740                        } else if (skip_prefix(arg, "--max-input-size=", &arg)) {
1741                                max_input_size = strtoumax(arg, NULL, 10);
1742                        } else
1743                                usage(index_pack_usage);
1744                        continue;
1745                }
1746
1747                if (pack_name)
1748                        usage(index_pack_usage);
1749                pack_name = arg;
1750        }
1751
1752        if (!pack_name && !from_stdin)
1753                usage(index_pack_usage);
1754        if (fix_thin_pack && !from_stdin)
1755                die(_("--fix-thin cannot be used without --stdin"));
1756        if (from_stdin && !startup_info->have_repository)
1757                die(_("--stdin requires a git repository"));
1758        if (!index_name && pack_name)
1759                index_name = derive_filename(pack_name, "idx", &index_name_buf);
1760
1761        if (verify) {
1762                if (!index_name)
1763                        die(_("--verify with no packfile name given"));
1764                read_idx_option(&opts, index_name);
1765                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1766        }
1767        if (strict)
1768                opts.flags |= WRITE_IDX_STRICT;
1769
1770        if (HAVE_THREADS && !nr_threads) {
1771                nr_threads = online_cpus();
1772                /* An experiment showed that more threads does not mean faster */
1773                if (nr_threads > 3)
1774                        nr_threads = 3;
1775        }
1776
1777        curr_pack = open_pack_file(pack_name);
1778        parse_pack_header();
1779        objects = xcalloc(st_add(nr_objects, 1), sizeof(struct object_entry));
1780        if (show_stat)
1781                obj_stat = xcalloc(st_add(nr_objects, 1), sizeof(struct object_stat));
1782        ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
1783        parse_pack_objects(pack_hash);
1784        if (report_end_of_input)
1785                write_in_full(2, "\0", 1);
1786        resolve_deltas();
1787        conclude_pack(fix_thin_pack, curr_pack, pack_hash);
1788        free(ofs_deltas);
1789        free(ref_deltas);
1790        if (strict)
1791                foreign_nr = check_objects();
1792
1793        if (show_stat)
1794                show_pack_info(stat_only);
1795
1796        ALLOC_ARRAY(idx_objects, nr_objects);
1797        for (i = 0; i < nr_objects; i++)
1798                idx_objects[i] = &objects[i].idx;
1799        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_hash);
1800        free(idx_objects);
1801
1802        if (!verify)
1803                final(pack_name, curr_pack,
1804                      index_name, curr_index,
1805                      keep_msg, promisor_msg,
1806                      pack_hash);
1807        else
1808                close(input_fd);
1809
1810        if (do_fsck_object && fsck_finish(&fsck_options))
1811                die(_("fsck error in pack objects"));
1812
1813        free(objects);
1814        strbuf_release(&index_name_buf);
1815        if (pack_name == NULL)
1816                free((void *) curr_pack);
1817        if (index_name == NULL)
1818                free((void *) curr_index);
1819
1820        /*
1821         * Let the caller know this pack is not self contained
1822         */
1823        if (check_self_contained_and_connected && foreign_nr)
1824                return 1;
1825
1826        return 0;
1827}