builtin / index-pack.con commit general improvements (43abf13)
   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#include "promisor-remote.h"
  18
  19static const char index_pack_usage[] =
  20"git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
  21
  22struct object_entry {
  23        struct pack_idx_entry idx;
  24        unsigned long size;
  25        unsigned char hdr_size;
  26        signed char type;
  27        signed char real_type;
  28};
  29
  30struct object_stat {
  31        unsigned delta_depth;
  32        int base_object_no;
  33};
  34
  35struct base_data {
  36        struct base_data *base;
  37        struct base_data *child;
  38        struct object_entry *obj;
  39        void *data;
  40        unsigned long size;
  41        int ref_first, ref_last;
  42        int ofs_first, ofs_last;
  43};
  44
  45struct thread_local {
  46        pthread_t thread;
  47        struct base_data *base_cache;
  48        size_t base_cache_used;
  49        int pack_fd;
  50};
  51
  52/* Remember to update object flag allocation in object.h */
  53#define FLAG_LINK (1u<<20)
  54#define FLAG_CHECKED (1u<<21)
  55
  56struct ofs_delta_entry {
  57        off_t offset;
  58        int obj_no;
  59};
  60
  61struct ref_delta_entry {
  62        struct object_id oid;
  63        int obj_no;
  64};
  65
  66static struct object_entry *objects;
  67static struct object_stat *obj_stat;
  68static struct ofs_delta_entry *ofs_deltas;
  69static struct ref_delta_entry *ref_deltas;
  70static struct thread_local nothread_data;
  71static int nr_objects;
  72static int nr_ofs_deltas;
  73static int nr_ref_deltas;
  74static int ref_deltas_alloc;
  75static int nr_resolved_deltas;
  76static int nr_threads;
  77
  78static int from_stdin;
  79static int strict;
  80static int do_fsck_object;
  81static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
  82static int verbose;
  83static int show_resolving_progress;
  84static int show_stat;
  85static int check_self_contained_and_connected;
  86
  87static struct progress *progress;
  88
  89/* We always read in 4kB chunks. */
  90static unsigned char input_buffer[4096];
  91static unsigned int input_offset, input_len;
  92static off_t consumed_bytes;
  93static off_t max_input_size;
  94static unsigned deepest_delta;
  95static git_hash_ctx input_ctx;
  96static uint32_t input_crc32;
  97static int input_fd, output_fd;
  98static const char *curr_pack;
  99
 100static struct thread_local *thread_data;
 101static int nr_dispatched;
 102static int threads_active;
 103
 104static pthread_mutex_t read_mutex;
 105#define read_lock()             lock_mutex(&read_mutex)
 106#define read_unlock()           unlock_mutex(&read_mutex)
 107
 108static pthread_mutex_t counter_mutex;
 109#define counter_lock()          lock_mutex(&counter_mutex)
 110#define counter_unlock()        unlock_mutex(&counter_mutex)
 111
 112static pthread_mutex_t work_mutex;
 113#define work_lock()             lock_mutex(&work_mutex)
 114#define work_unlock()           unlock_mutex(&work_mutex)
 115
 116static pthread_mutex_t deepest_delta_mutex;
 117#define deepest_delta_lock()    lock_mutex(&deepest_delta_mutex)
 118#define deepest_delta_unlock()  unlock_mutex(&deepest_delta_mutex)
 119
 120static pthread_mutex_t type_cas_mutex;
 121#define type_cas_lock()         lock_mutex(&type_cas_mutex)
 122#define type_cas_unlock()       unlock_mutex(&type_cas_mutex)
 123
 124static pthread_key_t key;
 125
 126static inline void lock_mutex(pthread_mutex_t *mutex)
 127{
 128        if (threads_active)
 129                pthread_mutex_lock(mutex);
 130}
 131
 132static inline void unlock_mutex(pthread_mutex_t *mutex)
 133{
 134        if (threads_active)
 135                pthread_mutex_unlock(mutex);
 136}
 137
 138/*
 139 * Mutex and conditional variable can't be statically-initialized on Windows.
 140 */
 141static void init_thread(void)
 142{
 143        int i;
 144        init_recursive_mutex(&read_mutex);
 145        pthread_mutex_init(&counter_mutex, NULL);
 146        pthread_mutex_init(&work_mutex, NULL);
 147        pthread_mutex_init(&type_cas_mutex, NULL);
 148        if (show_stat)
 149                pthread_mutex_init(&deepest_delta_mutex, NULL);
 150        pthread_key_create(&key, NULL);
 151        thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 152        for (i = 0; i < nr_threads; i++) {
 153                thread_data[i].pack_fd = open(curr_pack, O_RDONLY);
 154                if (thread_data[i].pack_fd == -1)
 155                        die_errno(_("unable to open %s"), curr_pack);
 156        }
 157
 158        threads_active = 1;
 159}
 160
 161static void cleanup_thread(void)
 162{
 163        int i;
 164        if (!threads_active)
 165                return;
 166        threads_active = 0;
 167        pthread_mutex_destroy(&read_mutex);
 168        pthread_mutex_destroy(&counter_mutex);
 169        pthread_mutex_destroy(&work_mutex);
 170        pthread_mutex_destroy(&type_cas_mutex);
 171        if (show_stat)
 172                pthread_mutex_destroy(&deepest_delta_mutex);
 173        for (i = 0; i < nr_threads; i++)
 174                close(thread_data[i].pack_fd);
 175        pthread_key_delete(key);
 176        free(thread_data);
 177}
 178
 179static int mark_link(struct object *obj, int type, void *data, struct fsck_options *options)
 180{
 181        if (!obj)
 182                return -1;
 183
 184        if (type != OBJ_ANY && obj->type != type)
 185                die(_("object type mismatch at %s"), oid_to_hex(&obj->oid));
 186
 187        obj->flags |= FLAG_LINK;
 188        return 0;
 189}
 190
 191/* The content of each linked object must have been checked
 192   or it must be already present in the object database */
 193static unsigned check_object(struct object *obj)
 194{
 195        if (!obj)
 196                return 0;
 197
 198        if (!(obj->flags & FLAG_LINK))
 199                return 0;
 200
 201        if (!(obj->flags & FLAG_CHECKED)) {
 202                unsigned long size;
 203                int type = oid_object_info(the_repository, &obj->oid, &size);
 204                if (type <= 0)
 205                        die(_("did not receive expected object %s"),
 206                              oid_to_hex(&obj->oid));
 207                if (type != obj->type)
 208                        die(_("object %s: expected type %s, found %s"),
 209                            oid_to_hex(&obj->oid),
 210                            type_name(obj->type), type_name(type));
 211                obj->flags |= FLAG_CHECKED;
 212                return 1;
 213        }
 214
 215        return 0;
 216}
 217
 218static unsigned check_objects(void)
 219{
 220        unsigned i, max, foreign_nr = 0;
 221
 222        max = get_max_object_index();
 223
 224        if (verbose)
 225                progress = start_delayed_progress(_("Checking objects"), max);
 226
 227        for (i = 0; i < max; i++) {
 228                foreign_nr += check_object(get_indexed_object(i));
 229                display_progress(progress, i + 1);
 230        }
 231
 232        stop_progress(&progress);
 233        return foreign_nr;
 234}
 235
 236
 237/* Discard current buffer used content. */
 238static void flush(void)
 239{
 240        if (input_offset) {
 241                if (output_fd >= 0)
 242                        write_or_die(output_fd, input_buffer, input_offset);
 243                the_hash_algo->update_fn(&input_ctx, input_buffer, input_offset);
 244                memmove(input_buffer, input_buffer + input_offset, input_len);
 245                input_offset = 0;
 246        }
 247}
 248
 249/*
 250 * Make sure at least "min" bytes are available in the buffer, and
 251 * return the pointer to the buffer.
 252 */
 253static void *fill(int min)
 254{
 255        if (min <= input_len)
 256                return input_buffer + input_offset;
 257        if (min > sizeof(input_buffer))
 258                die(Q_("cannot fill %d byte",
 259                       "cannot fill %d bytes",
 260                       min),
 261                    min);
 262        flush();
 263        do {
 264                ssize_t ret = xread(input_fd, input_buffer + input_len,
 265                                sizeof(input_buffer) - input_len);
 266                if (ret <= 0) {
 267                        if (!ret)
 268                                die(_("early EOF"));
 269                        die_errno(_("read error on input"));
 270                }
 271                input_len += ret;
 272                if (from_stdin)
 273                        display_throughput(progress, consumed_bytes + input_len);
 274        } while (input_len < min);
 275        return input_buffer;
 276}
 277
 278static void use(int bytes)
 279{
 280        if (bytes > input_len)
 281                die(_("used more bytes than were available"));
 282        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 283        input_len -= bytes;
 284        input_offset += bytes;
 285
 286        /* make sure off_t is sufficiently large not to wrap */
 287        if (signed_add_overflows(consumed_bytes, bytes))
 288                die(_("pack too large for current definition of off_t"));
 289        consumed_bytes += bytes;
 290        if (max_input_size && consumed_bytes > max_input_size)
 291                die(_("pack exceeds maximum allowed size"));
 292}
 293
 294static const char *open_pack_file(const char *pack_name)
 295{
 296        if (from_stdin) {
 297                input_fd = 0;
 298                if (!pack_name) {
 299                        struct strbuf tmp_file = STRBUF_INIT;
 300                        output_fd = odb_mkstemp(&tmp_file,
 301                                                "pack/tmp_pack_XXXXXX");
 302                        pack_name = strbuf_detach(&tmp_file, NULL);
 303                } else {
 304                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 305                        if (output_fd < 0)
 306                                die_errno(_("unable to create '%s'"), pack_name);
 307                }
 308                nothread_data.pack_fd = output_fd;
 309        } else {
 310                input_fd = open(pack_name, O_RDONLY);
 311                if (input_fd < 0)
 312                        die_errno(_("cannot open packfile '%s'"), pack_name);
 313                output_fd = -1;
 314                nothread_data.pack_fd = input_fd;
 315        }
 316        the_hash_algo->init_fn(&input_ctx);
 317        return pack_name;
 318}
 319
 320static void parse_pack_header(void)
 321{
 322        struct pack_header *hdr = fill(sizeof(struct pack_header));
 323
 324        /* Header consistency check */
 325        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 326                die(_("pack signature mismatch"));
 327        if (!pack_version_ok(hdr->hdr_version))
 328                die(_("pack version %"PRIu32" unsupported"),
 329                        ntohl(hdr->hdr_version));
 330
 331        nr_objects = ntohl(hdr->hdr_entries);
 332        use(sizeof(struct pack_header));
 333}
 334
 335static NORETURN void bad_object(off_t offset, const char *format,
 336                       ...) __attribute__((format (printf, 2, 3)));
 337
 338static NORETURN void bad_object(off_t offset, const char *format, ...)
 339{
 340        va_list params;
 341        char buf[1024];
 342
 343        va_start(params, format);
 344        vsnprintf(buf, sizeof(buf), format, params);
 345        va_end(params);
 346        die(_("pack has bad object at offset %"PRIuMAX": %s"),
 347            (uintmax_t)offset, buf);
 348}
 349
 350static inline struct thread_local *get_thread_data(void)
 351{
 352        if (HAVE_THREADS) {
 353                if (threads_active)
 354                        return pthread_getspecific(key);
 355                assert(!threads_active &&
 356                       "This should only be reached when all threads are gone");
 357        }
 358        return &nothread_data;
 359}
 360
 361static void set_thread_data(struct thread_local *data)
 362{
 363        if (threads_active)
 364                pthread_setspecific(key, data);
 365}
 366
 367static struct base_data *alloc_base_data(void)
 368{
 369        struct base_data *base = xcalloc(1, sizeof(struct base_data));
 370        base->ref_last = -1;
 371        base->ofs_last = -1;
 372        return base;
 373}
 374
 375static void free_base_data(struct base_data *c)
 376{
 377        if (c->data) {
 378                FREE_AND_NULL(c->data);
 379                get_thread_data()->base_cache_used -= c->size;
 380        }
 381}
 382
 383static void prune_base_data(struct base_data *retain)
 384{
 385        struct base_data *b;
 386        struct thread_local *data = get_thread_data();
 387        for (b = data->base_cache;
 388             data->base_cache_used > delta_base_cache_limit && b;
 389             b = b->child) {
 390                if (b->data && b != retain)
 391                        free_base_data(b);
 392        }
 393}
 394
 395static void link_base_data(struct base_data *base, struct base_data *c)
 396{
 397        if (base)
 398                base->child = c;
 399        else
 400                get_thread_data()->base_cache = c;
 401
 402        c->base = base;
 403        c->child = NULL;
 404        if (c->data)
 405                get_thread_data()->base_cache_used += c->size;
 406        prune_base_data(c);
 407}
 408
 409static void unlink_base_data(struct base_data *c)
 410{
 411        struct base_data *base = c->base;
 412        if (base)
 413                base->child = NULL;
 414        else
 415                get_thread_data()->base_cache = NULL;
 416        free_base_data(c);
 417}
 418
 419static int is_delta_type(enum object_type type)
 420{
 421        return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 422}
 423
 424static void *unpack_entry_data(off_t offset, unsigned long size,
 425                               enum object_type type, struct object_id *oid)
 426{
 427        static char fixed_buf[8192];
 428        int status;
 429        git_zstream stream;
 430        void *buf;
 431        git_hash_ctx c;
 432        char hdr[32];
 433        int hdrlen;
 434
 435        if (!is_delta_type(type)) {
 436                hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX,
 437                                   type_name(type),(uintmax_t)size) + 1;
 438                the_hash_algo->init_fn(&c);
 439                the_hash_algo->update_fn(&c, hdr, hdrlen);
 440        } else
 441                oid = NULL;
 442        if (type == OBJ_BLOB && size > big_file_threshold)
 443                buf = fixed_buf;
 444        else
 445                buf = xmallocz(size);
 446
 447        memset(&stream, 0, sizeof(stream));
 448        git_inflate_init(&stream);
 449        stream.next_out = buf;
 450        stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 451
 452        do {
 453                unsigned char *last_out = stream.next_out;
 454                stream.next_in = fill(1);
 455                stream.avail_in = input_len;
 456                status = git_inflate(&stream, 0);
 457                use(input_len - stream.avail_in);
 458                if (oid)
 459                        the_hash_algo->update_fn(&c, last_out, stream.next_out - last_out);
 460                if (buf == fixed_buf) {
 461                        stream.next_out = buf;
 462                        stream.avail_out = sizeof(fixed_buf);
 463                }
 464        } while (status == Z_OK);
 465        if (stream.total_out != size || status != Z_STREAM_END)
 466                bad_object(offset, _("inflate returned %d"), status);
 467        git_inflate_end(&stream);
 468        if (oid)
 469                the_hash_algo->final_fn(oid->hash, &c);
 470        return buf == fixed_buf ? NULL : buf;
 471}
 472
 473static void *unpack_raw_entry(struct object_entry *obj,
 474                              off_t *ofs_offset,
 475                              struct object_id *ref_oid,
 476                              struct object_id *oid)
 477{
 478        unsigned char *p;
 479        unsigned long size, c;
 480        off_t base_offset;
 481        unsigned shift;
 482        void *data;
 483
 484        obj->idx.offset = consumed_bytes;
 485        input_crc32 = crc32(0, NULL, 0);
 486
 487        p = fill(1);
 488        c = *p;
 489        use(1);
 490        obj->type = (c >> 4) & 7;
 491        size = (c & 15);
 492        shift = 4;
 493        while (c & 0x80) {
 494                p = fill(1);
 495                c = *p;
 496                use(1);
 497                size += (c & 0x7f) << shift;
 498                shift += 7;
 499        }
 500        obj->size = size;
 501
 502        switch (obj->type) {
 503        case OBJ_REF_DELTA:
 504                hashcpy(ref_oid->hash, fill(the_hash_algo->rawsz));
 505                use(the_hash_algo->rawsz);
 506                break;
 507        case OBJ_OFS_DELTA:
 508                p = fill(1);
 509                c = *p;
 510                use(1);
 511                base_offset = c & 127;
 512                while (c & 128) {
 513                        base_offset += 1;
 514                        if (!base_offset || MSB(base_offset, 7))
 515                                bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 516                        p = fill(1);
 517                        c = *p;
 518                        use(1);
 519                        base_offset = (base_offset << 7) + (c & 127);
 520                }
 521                *ofs_offset = obj->idx.offset - base_offset;
 522                if (*ofs_offset <= 0 || *ofs_offset >= obj->idx.offset)
 523                        bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 524                break;
 525        case OBJ_COMMIT:
 526        case OBJ_TREE:
 527        case OBJ_BLOB:
 528        case OBJ_TAG:
 529                break;
 530        default:
 531                bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 532        }
 533        obj->hdr_size = consumed_bytes - obj->idx.offset;
 534
 535        data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, oid);
 536        obj->idx.crc32 = input_crc32;
 537        return data;
 538}
 539
 540static void *unpack_data(struct object_entry *obj,
 541                         int (*consume)(const unsigned char *, unsigned long, void *),
 542                         void *cb_data)
 543{
 544        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 545        off_t len = obj[1].idx.offset - from;
 546        unsigned char *data, *inbuf;
 547        git_zstream stream;
 548        int status;
 549
 550        data = xmallocz(consume ? 64*1024 : obj->size);
 551        inbuf = xmalloc((len < 64*1024) ? (int)len : 64*1024);
 552
 553        memset(&stream, 0, sizeof(stream));
 554        git_inflate_init(&stream);
 555        stream.next_out = data;
 556        stream.avail_out = consume ? 64*1024 : obj->size;
 557
 558        do {
 559                ssize_t n = (len < 64*1024) ? (ssize_t)len : 64*1024;
 560                n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 561                if (n < 0)
 562                        die_errno(_("cannot pread pack file"));
 563                if (!n)
 564                        die(Q_("premature end of pack file, %"PRIuMAX" byte missing",
 565                               "premature end of pack file, %"PRIuMAX" bytes missing",
 566                               (unsigned int)len),
 567                            (uintmax_t)len);
 568                from += n;
 569                len -= n;
 570                stream.next_in = inbuf;
 571                stream.avail_in = n;
 572                if (!consume)
 573                        status = git_inflate(&stream, 0);
 574                else {
 575                        do {
 576                                status = git_inflate(&stream, 0);
 577                                if (consume(data, stream.next_out - data, cb_data)) {
 578                                        free(inbuf);
 579                                        free(data);
 580                                        return NULL;
 581                                }
 582                                stream.next_out = data;
 583                                stream.avail_out = 64*1024;
 584                        } while (status == Z_OK && stream.avail_in);
 585                }
 586        } while (len && status == Z_OK && !stream.avail_in);
 587
 588        /* This has been inflated OK when first encountered, so... */
 589        if (status != Z_STREAM_END || stream.total_out != obj->size)
 590                die(_("serious inflate inconsistency"));
 591
 592        git_inflate_end(&stream);
 593        free(inbuf);
 594        if (consume) {
 595                FREE_AND_NULL(data);
 596        }
 597        return data;
 598}
 599
 600static void *get_data_from_pack(struct object_entry *obj)
 601{
 602        return unpack_data(obj, NULL, NULL);
 603}
 604
 605static int compare_ofs_delta_bases(off_t offset1, off_t offset2,
 606                                   enum object_type type1,
 607                                   enum object_type type2)
 608{
 609        int cmp = type1 - type2;
 610        if (cmp)
 611                return cmp;
 612        return offset1 < offset2 ? -1 :
 613               offset1 > offset2 ?  1 :
 614               0;
 615}
 616
 617static int find_ofs_delta(const off_t offset, enum object_type type)
 618{
 619        int first = 0, last = nr_ofs_deltas;
 620
 621        while (first < last) {
 622                int next = first + (last - first) / 2;
 623                struct ofs_delta_entry *delta = &ofs_deltas[next];
 624                int cmp;
 625
 626                cmp = compare_ofs_delta_bases(offset, delta->offset,
 627                                              type, objects[delta->obj_no].type);
 628                if (!cmp)
 629                        return next;
 630                if (cmp < 0) {
 631                        last = next;
 632                        continue;
 633                }
 634                first = next+1;
 635        }
 636        return -first-1;
 637}
 638
 639static void find_ofs_delta_children(off_t offset,
 640                                    int *first_index, int *last_index,
 641                                    enum object_type type)
 642{
 643        int first = find_ofs_delta(offset, type);
 644        int last = first;
 645        int end = nr_ofs_deltas - 1;
 646
 647        if (first < 0) {
 648                *first_index = 0;
 649                *last_index = -1;
 650                return;
 651        }
 652        while (first > 0 && ofs_deltas[first - 1].offset == offset)
 653                --first;
 654        while (last < end && ofs_deltas[last + 1].offset == offset)
 655                ++last;
 656        *first_index = first;
 657        *last_index = last;
 658}
 659
 660static int compare_ref_delta_bases(const struct object_id *oid1,
 661                                   const struct object_id *oid2,
 662                                   enum object_type type1,
 663                                   enum object_type type2)
 664{
 665        int cmp = type1 - type2;
 666        if (cmp)
 667                return cmp;
 668        return oidcmp(oid1, oid2);
 669}
 670
 671static int find_ref_delta(const struct object_id *oid, enum object_type type)
 672{
 673        int first = 0, last = nr_ref_deltas;
 674
 675        while (first < last) {
 676                int next = first + (last - first) / 2;
 677                struct ref_delta_entry *delta = &ref_deltas[next];
 678                int cmp;
 679
 680                cmp = compare_ref_delta_bases(oid, &delta->oid,
 681                                              type, objects[delta->obj_no].type);
 682                if (!cmp)
 683                        return next;
 684                if (cmp < 0) {
 685                        last = next;
 686                        continue;
 687                }
 688                first = next+1;
 689        }
 690        return -first-1;
 691}
 692
 693static void find_ref_delta_children(const struct object_id *oid,
 694                                    int *first_index, int *last_index,
 695                                    enum object_type type)
 696{
 697        int first = find_ref_delta(oid, type);
 698        int last = first;
 699        int end = nr_ref_deltas - 1;
 700
 701        if (first < 0) {
 702                *first_index = 0;
 703                *last_index = -1;
 704                return;
 705        }
 706        while (first > 0 && oideq(&ref_deltas[first - 1].oid, oid))
 707                --first;
 708        while (last < end && oideq(&ref_deltas[last + 1].oid, oid))
 709                ++last;
 710        *first_index = first;
 711        *last_index = last;
 712}
 713
 714struct compare_data {
 715        struct object_entry *entry;
 716        struct git_istream *st;
 717        unsigned char *buf;
 718        unsigned long buf_size;
 719};
 720
 721static int compare_objects(const unsigned char *buf, unsigned long size,
 722                           void *cb_data)
 723{
 724        struct compare_data *data = cb_data;
 725
 726        if (data->buf_size < size) {
 727                free(data->buf);
 728                data->buf = xmalloc(size);
 729                data->buf_size = size;
 730        }
 731
 732        while (size) {
 733                ssize_t len = read_istream(data->st, data->buf, size);
 734                if (len == 0)
 735                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 736                            oid_to_hex(&data->entry->idx.oid));
 737                if (len < 0)
 738                        die(_("unable to read %s"),
 739                            oid_to_hex(&data->entry->idx.oid));
 740                if (memcmp(buf, data->buf, len))
 741                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 742                            oid_to_hex(&data->entry->idx.oid));
 743                size -= len;
 744                buf += len;
 745        }
 746        return 0;
 747}
 748
 749static int check_collison(struct object_entry *entry)
 750{
 751        struct compare_data data;
 752        enum object_type type;
 753        unsigned long size;
 754
 755        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 756                return -1;
 757
 758        memset(&data, 0, sizeof(data));
 759        data.entry = entry;
 760        data.st = open_istream(&entry->idx.oid, &type, &size, NULL);
 761        if (!data.st)
 762                return -1;
 763        if (size != entry->size || type != entry->type)
 764                die(_("SHA1 COLLISION FOUND WITH %s !"),
 765                    oid_to_hex(&entry->idx.oid));
 766        unpack_data(entry, compare_objects, &data);
 767        close_istream(data.st);
 768        free(data.buf);
 769        return 0;
 770}
 771
 772static void sha1_object(const void *data, struct object_entry *obj_entry,
 773                        unsigned long size, enum object_type type,
 774                        const struct object_id *oid)
 775{
 776        void *new_data = NULL;
 777        int collision_test_needed = 0;
 778
 779        assert(data || obj_entry);
 780
 781        if (startup_info->have_repository) {
 782                read_lock();
 783                collision_test_needed =
 784                        has_object_file_with_flags(oid, OBJECT_INFO_QUICK);
 785                read_unlock();
 786        }
 787
 788        if (collision_test_needed && !data) {
 789                read_lock();
 790                if (!check_collison(obj_entry))
 791                        collision_test_needed = 0;
 792                read_unlock();
 793        }
 794        if (collision_test_needed) {
 795                void *has_data;
 796                enum object_type has_type;
 797                unsigned long has_size;
 798                read_lock();
 799                has_type = oid_object_info(the_repository, oid, &has_size);
 800                if (has_type < 0)
 801                        die(_("cannot read existing object info %s"), oid_to_hex(oid));
 802                if (has_type != type || has_size != size)
 803                        die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 804                has_data = read_object_file(oid, &has_type, &has_size);
 805                read_unlock();
 806                if (!data)
 807                        data = new_data = get_data_from_pack(obj_entry);
 808                if (!has_data)
 809                        die(_("cannot read existing object %s"), oid_to_hex(oid));
 810                if (size != has_size || type != has_type ||
 811                    memcmp(data, has_data, size) != 0)
 812                        die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 813                free(has_data);
 814        }
 815
 816        if (strict || do_fsck_object) {
 817                read_lock();
 818                if (type == OBJ_BLOB) {
 819                        struct blob *blob = lookup_blob(the_repository, oid);
 820                        if (blob)
 821                                blob->object.flags |= FLAG_CHECKED;
 822                        else
 823                                die(_("invalid blob object %s"), oid_to_hex(oid));
 824                        if (do_fsck_object &&
 825                            fsck_object(&blob->object, (void *)data, size, &fsck_options))
 826                                die(_("fsck error in packed object"));
 827                } else {
 828                        struct object *obj;
 829                        int eaten;
 830                        void *buf = (void *) data;
 831
 832                        assert(data && "data can only be NULL for large _blobs_");
 833
 834                        /*
 835                         * we do not need to free the memory here, as the
 836                         * buf is deleted by the caller.
 837                         */
 838                        obj = parse_object_buffer(the_repository, oid, type,
 839                                                  size, buf,
 840                                                  &eaten);
 841                        if (!obj)
 842                                die(_("invalid %s"), type_name(type));
 843                        if (do_fsck_object &&
 844                            fsck_object(obj, buf, size, &fsck_options))
 845                                die(_("fsck error in packed object"));
 846                        if (strict && fsck_walk(obj, NULL, &fsck_options))
 847                                die(_("Not all child objects of %s are reachable"), oid_to_hex(&obj->oid));
 848
 849                        if (obj->type == OBJ_TREE) {
 850                                struct tree *item = (struct tree *) obj;
 851                                item->buffer = NULL;
 852                                obj->parsed = 0;
 853                        }
 854                        if (obj->type == OBJ_COMMIT) {
 855                                struct commit *commit = (struct commit *) obj;
 856                                if (detach_commit_buffer(commit, NULL) != data)
 857                                        BUG("parse_object_buffer transmogrified our buffer");
 858                        }
 859                        obj->flags |= FLAG_CHECKED;
 860                }
 861                read_unlock();
 862        }
 863
 864        free(new_data);
 865}
 866
 867/*
 868 * This function is part of find_unresolved_deltas(). There are two
 869 * walkers going in the opposite ways.
 870 *
 871 * The first one in find_unresolved_deltas() traverses down from
 872 * parent node to children, deflating nodes along the way. However,
 873 * memory for deflated nodes is limited by delta_base_cache_limit, so
 874 * at some point parent node's deflated content may be freed.
 875 *
 876 * The second walker is this function, which goes from current node up
 877 * to top parent if necessary to deflate the node. In normal
 878 * situation, its parent node would be already deflated, so it just
 879 * needs to apply delta.
 880 *
 881 * In the worst case scenario, parent node is no longer deflated because
 882 * we're running out of delta_base_cache_limit; we need to re-deflate
 883 * parents, possibly up to the top base.
 884 *
 885 * All deflated objects here are subject to be freed if we exceed
 886 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 887 * just need to make sure the last node is not freed.
 888 */
 889static void *get_base_data(struct base_data *c)
 890{
 891        if (!c->data) {
 892                struct object_entry *obj = c->obj;
 893                struct base_data **delta = NULL;
 894                int delta_nr = 0, delta_alloc = 0;
 895
 896                while (is_delta_type(c->obj->type) && !c->data) {
 897                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 898                        delta[delta_nr++] = c;
 899                        c = c->base;
 900                }
 901                if (!delta_nr) {
 902                        c->data = get_data_from_pack(obj);
 903                        c->size = obj->size;
 904                        get_thread_data()->base_cache_used += c->size;
 905                        prune_base_data(c);
 906                }
 907                for (; delta_nr > 0; delta_nr--) {
 908                        void *base, *raw;
 909                        c = delta[delta_nr - 1];
 910                        obj = c->obj;
 911                        base = get_base_data(c->base);
 912                        raw = get_data_from_pack(obj);
 913                        c->data = patch_delta(
 914                                base, c->base->size,
 915                                raw, obj->size,
 916                                &c->size);
 917                        free(raw);
 918                        if (!c->data)
 919                                bad_object(obj->idx.offset, _("failed to apply delta"));
 920                        get_thread_data()->base_cache_used += c->size;
 921                        prune_base_data(c);
 922                }
 923                free(delta);
 924        }
 925        return c->data;
 926}
 927
 928static void resolve_delta(struct object_entry *delta_obj,
 929                          struct base_data *base, struct base_data *result)
 930{
 931        void *base_data, *delta_data;
 932
 933        if (show_stat) {
 934                int i = delta_obj - objects;
 935                int j = base->obj - objects;
 936                obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 937                deepest_delta_lock();
 938                if (deepest_delta < obj_stat[i].delta_depth)
 939                        deepest_delta = obj_stat[i].delta_depth;
 940                deepest_delta_unlock();
 941                obj_stat[i].base_object_no = j;
 942        }
 943        delta_data = get_data_from_pack(delta_obj);
 944        base_data = get_base_data(base);
 945        result->obj = delta_obj;
 946        result->data = patch_delta(base_data, base->size,
 947                                   delta_data, delta_obj->size, &result->size);
 948        free(delta_data);
 949        if (!result->data)
 950                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 951        hash_object_file(result->data, result->size,
 952                         type_name(delta_obj->real_type), &delta_obj->idx.oid);
 953        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 954                    &delta_obj->idx.oid);
 955        counter_lock();
 956        nr_resolved_deltas++;
 957        counter_unlock();
 958}
 959
 960/*
 961 * Standard boolean compare-and-swap: atomically check whether "*type" is
 962 * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 963 * and return false.
 964 */
 965static int compare_and_swap_type(signed char *type,
 966                                 enum object_type want,
 967                                 enum object_type set)
 968{
 969        enum object_type old;
 970
 971        type_cas_lock();
 972        old = *type;
 973        if (old == want)
 974                *type = set;
 975        type_cas_unlock();
 976
 977        return old == want;
 978}
 979
 980static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 981                                                  struct base_data *prev_base)
 982{
 983        if (base->ref_last == -1 && base->ofs_last == -1) {
 984                find_ref_delta_children(&base->obj->idx.oid,
 985                                        &base->ref_first, &base->ref_last,
 986                                        OBJ_REF_DELTA);
 987
 988                find_ofs_delta_children(base->obj->idx.offset,
 989                                        &base->ofs_first, &base->ofs_last,
 990                                        OBJ_OFS_DELTA);
 991
 992                if (base->ref_last == -1 && base->ofs_last == -1) {
 993                        free(base->data);
 994                        return NULL;
 995                }
 996
 997                link_base_data(prev_base, base);
 998        }
 999
1000        if (base->ref_first <= base->ref_last) {
1001                struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
1002                struct base_data *result = alloc_base_data();
1003
1004                if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
1005                                           base->obj->real_type))
1006                        BUG("child->real_type != OBJ_REF_DELTA");
1007
1008                resolve_delta(child, base, result);
1009                if (base->ref_first == base->ref_last && base->ofs_last == -1)
1010                        free_base_data(base);
1011
1012                base->ref_first++;
1013                return result;
1014        }
1015
1016        if (base->ofs_first <= base->ofs_last) {
1017                struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
1018                struct base_data *result = alloc_base_data();
1019
1020                assert(child->real_type == OBJ_OFS_DELTA);
1021                child->real_type = base->obj->real_type;
1022                resolve_delta(child, base, result);
1023                if (base->ofs_first == base->ofs_last)
1024                        free_base_data(base);
1025
1026                base->ofs_first++;
1027                return result;
1028        }
1029
1030        unlink_base_data(base);
1031        return NULL;
1032}
1033
1034static void find_unresolved_deltas(struct base_data *base)
1035{
1036        struct base_data *new_base, *prev_base = NULL;
1037        for (;;) {
1038                new_base = find_unresolved_deltas_1(base, prev_base);
1039
1040                if (new_base) {
1041                        prev_base = base;
1042                        base = new_base;
1043                } else {
1044                        free(base);
1045                        base = prev_base;
1046                        if (!base)
1047                                return;
1048                        prev_base = base->base;
1049                }
1050        }
1051}
1052
1053static int compare_ofs_delta_entry(const void *a, const void *b)
1054{
1055        const struct ofs_delta_entry *delta_a = a;
1056        const struct ofs_delta_entry *delta_b = b;
1057
1058        return delta_a->offset < delta_b->offset ? -1 :
1059               delta_a->offset > delta_b->offset ?  1 :
1060               0;
1061}
1062
1063static int compare_ref_delta_entry(const void *a, const void *b)
1064{
1065        const struct ref_delta_entry *delta_a = a;
1066        const struct ref_delta_entry *delta_b = b;
1067
1068        return oidcmp(&delta_a->oid, &delta_b->oid);
1069}
1070
1071static void resolve_base(struct object_entry *obj)
1072{
1073        struct base_data *base_obj = alloc_base_data();
1074        base_obj->obj = obj;
1075        base_obj->data = NULL;
1076        find_unresolved_deltas(base_obj);
1077}
1078
1079static void *threaded_second_pass(void *data)
1080{
1081        set_thread_data(data);
1082        for (;;) {
1083                int i;
1084                counter_lock();
1085                display_progress(progress, nr_resolved_deltas);
1086                counter_unlock();
1087                work_lock();
1088                while (nr_dispatched < nr_objects &&
1089                       is_delta_type(objects[nr_dispatched].type))
1090                        nr_dispatched++;
1091                if (nr_dispatched >= nr_objects) {
1092                        work_unlock();
1093                        break;
1094                }
1095                i = nr_dispatched++;
1096                work_unlock();
1097
1098                resolve_base(&objects[i]);
1099        }
1100        return NULL;
1101}
1102
1103/*
1104 * First pass:
1105 * - find locations of all objects;
1106 * - calculate SHA1 of all non-delta objects;
1107 * - remember base (SHA1 or offset) for all deltas.
1108 */
1109static void parse_pack_objects(unsigned char *hash)
1110{
1111        int i, nr_delays = 0;
1112        struct ofs_delta_entry *ofs_delta = ofs_deltas;
1113        struct object_id ref_delta_oid;
1114        struct stat st;
1115
1116        if (verbose)
1117                progress = start_progress(
1118                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1119                                nr_objects);
1120        for (i = 0; i < nr_objects; i++) {
1121                struct object_entry *obj = &objects[i];
1122                void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1123                                              &ref_delta_oid,
1124                                              &obj->idx.oid);
1125                obj->real_type = obj->type;
1126                if (obj->type == OBJ_OFS_DELTA) {
1127                        nr_ofs_deltas++;
1128                        ofs_delta->obj_no = i;
1129                        ofs_delta++;
1130                } else if (obj->type == OBJ_REF_DELTA) {
1131                        ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1132                        oidcpy(&ref_deltas[nr_ref_deltas].oid, &ref_delta_oid);
1133                        ref_deltas[nr_ref_deltas].obj_no = i;
1134                        nr_ref_deltas++;
1135                } else if (!data) {
1136                        /* large blobs, check later */
1137                        obj->real_type = OBJ_BAD;
1138                        nr_delays++;
1139                } else
1140                        sha1_object(data, NULL, obj->size, obj->type,
1141                                    &obj->idx.oid);
1142                free(data);
1143                display_progress(progress, i+1);
1144        }
1145        objects[i].idx.offset = consumed_bytes;
1146        stop_progress(&progress);
1147
1148        /* Check pack integrity */
1149        flush();
1150        the_hash_algo->final_fn(hash, &input_ctx);
1151        if (!hasheq(fill(the_hash_algo->rawsz), hash))
1152                die(_("pack is corrupted (SHA1 mismatch)"));
1153        use(the_hash_algo->rawsz);
1154
1155        /* If input_fd is a file, we should have reached its end now. */
1156        if (fstat(input_fd, &st))
1157                die_errno(_("cannot fstat packfile"));
1158        if (S_ISREG(st.st_mode) &&
1159                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1160                die(_("pack has junk at the end"));
1161
1162        for (i = 0; i < nr_objects; i++) {
1163                struct object_entry *obj = &objects[i];
1164                if (obj->real_type != OBJ_BAD)
1165                        continue;
1166                obj->real_type = obj->type;
1167                sha1_object(NULL, obj, obj->size, obj->type,
1168                            &obj->idx.oid);
1169                nr_delays--;
1170        }
1171        if (nr_delays)
1172                die(_("confusion beyond insanity in parse_pack_objects()"));
1173}
1174
1175/*
1176 * Second pass:
1177 * - for all non-delta objects, look if it is used as a base for
1178 *   deltas;
1179 * - if used as a base, uncompress the object and apply all deltas,
1180 *   recursively checking if the resulting object is used as a base
1181 *   for some more deltas.
1182 */
1183static void resolve_deltas(void)
1184{
1185        int i;
1186
1187        if (!nr_ofs_deltas && !nr_ref_deltas)
1188                return;
1189
1190        /* Sort deltas by base SHA1/offset for fast searching */
1191        QSORT(ofs_deltas, nr_ofs_deltas, compare_ofs_delta_entry);
1192        QSORT(ref_deltas, nr_ref_deltas, compare_ref_delta_entry);
1193
1194        if (verbose || show_resolving_progress)
1195                progress = start_progress(_("Resolving deltas"),
1196                                          nr_ref_deltas + nr_ofs_deltas);
1197
1198        nr_dispatched = 0;
1199        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1200                init_thread();
1201                for (i = 0; i < nr_threads; i++) {
1202                        int ret = pthread_create(&thread_data[i].thread, NULL,
1203                                                 threaded_second_pass, thread_data + i);
1204                        if (ret)
1205                                die(_("unable to create thread: %s"),
1206                                    strerror(ret));
1207                }
1208                for (i = 0; i < nr_threads; i++)
1209                        pthread_join(thread_data[i].thread, NULL);
1210                cleanup_thread();
1211                return;
1212        }
1213
1214        for (i = 0; i < nr_objects; i++) {
1215                struct object_entry *obj = &objects[i];
1216
1217                if (is_delta_type(obj->type))
1218                        continue;
1219                resolve_base(obj);
1220                display_progress(progress, nr_resolved_deltas);
1221        }
1222}
1223
1224/*
1225 * Third pass:
1226 * - append objects to convert thin pack to full pack if required
1227 * - write the final pack hash
1228 */
1229static void fix_unresolved_deltas(struct hashfile *f);
1230static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_hash)
1231{
1232        if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1233                stop_progress(&progress);
1234                /* Flush remaining pack final hash. */
1235                flush();
1236                return;
1237        }
1238
1239        if (fix_thin_pack) {
1240                struct hashfile *f;
1241                unsigned char read_hash[GIT_MAX_RAWSZ], tail_hash[GIT_MAX_RAWSZ];
1242                struct strbuf msg = STRBUF_INIT;
1243                int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1244                int nr_objects_initial = nr_objects;
1245                if (nr_unresolved <= 0)
1246                        die(_("confusion beyond insanity"));
1247                REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1248                memset(objects + nr_objects + 1, 0,
1249                       nr_unresolved * sizeof(*objects));
1250                f = hashfd(output_fd, curr_pack);
1251                fix_unresolved_deltas(f);
1252                strbuf_addf(&msg, Q_("completed with %d local object",
1253                                     "completed with %d local objects",
1254                                     nr_objects - nr_objects_initial),
1255                            nr_objects - nr_objects_initial);
1256                stop_progress_msg(&progress, msg.buf);
1257                strbuf_release(&msg);
1258                finalize_hashfile(f, tail_hash, 0);
1259                hashcpy(read_hash, pack_hash);
1260                fixup_pack_header_footer(output_fd, pack_hash,
1261                                         curr_pack, nr_objects,
1262                                         read_hash, consumed_bytes-the_hash_algo->rawsz);
1263                if (!hasheq(read_hash, tail_hash))
1264                        die(_("Unexpected tail checksum for %s "
1265                              "(disk corruption?)"), curr_pack);
1266        }
1267        if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1268                die(Q_("pack has %d unresolved delta",
1269                       "pack has %d unresolved deltas",
1270                       nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1271                    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1272}
1273
1274static int write_compressed(struct hashfile *f, void *in, unsigned int size)
1275{
1276        git_zstream stream;
1277        int status;
1278        unsigned char outbuf[4096];
1279
1280        git_deflate_init(&stream, zlib_compression_level);
1281        stream.next_in = in;
1282        stream.avail_in = size;
1283
1284        do {
1285                stream.next_out = outbuf;
1286                stream.avail_out = sizeof(outbuf);
1287                status = git_deflate(&stream, Z_FINISH);
1288                hashwrite(f, outbuf, sizeof(outbuf) - stream.avail_out);
1289        } while (status == Z_OK);
1290
1291        if (status != Z_STREAM_END)
1292                die(_("unable to deflate appended object (%d)"), status);
1293        size = stream.total_out;
1294        git_deflate_end(&stream);
1295        return size;
1296}
1297
1298static struct object_entry *append_obj_to_pack(struct hashfile *f,
1299                               const unsigned char *sha1, void *buf,
1300                               unsigned long size, enum object_type type)
1301{
1302        struct object_entry *obj = &objects[nr_objects++];
1303        unsigned char header[10];
1304        unsigned long s = size;
1305        int n = 0;
1306        unsigned char c = (type << 4) | (s & 15);
1307        s >>= 4;
1308        while (s) {
1309                header[n++] = c | 0x80;
1310                c = s & 0x7f;
1311                s >>= 7;
1312        }
1313        header[n++] = c;
1314        crc32_begin(f);
1315        hashwrite(f, header, n);
1316        obj[0].size = size;
1317        obj[0].hdr_size = n;
1318        obj[0].type = type;
1319        obj[0].real_type = type;
1320        obj[1].idx.offset = obj[0].idx.offset + n;
1321        obj[1].idx.offset += write_compressed(f, buf, size);
1322        obj[0].idx.crc32 = crc32_end(f);
1323        hashflush(f);
1324        hashcpy(obj->idx.oid.hash, sha1);
1325        return obj;
1326}
1327
1328static int delta_pos_compare(const void *_a, const void *_b)
1329{
1330        struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1331        struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1332        return a->obj_no - b->obj_no;
1333}
1334
1335static void fix_unresolved_deltas(struct hashfile *f)
1336{
1337        struct ref_delta_entry **sorted_by_pos;
1338        int i;
1339
1340        /*
1341         * Since many unresolved deltas may well be themselves base objects
1342         * for more unresolved deltas, we really want to include the
1343         * smallest number of base objects that would cover as much delta
1344         * as possible by picking the
1345         * trunc deltas first, allowing for other deltas to resolve without
1346         * additional base objects.  Since most base objects are to be found
1347         * before deltas depending on them, a good heuristic is to start
1348         * resolving deltas in the same order as their position in the pack.
1349         */
1350        ALLOC_ARRAY(sorted_by_pos, nr_ref_deltas);
1351        for (i = 0; i < nr_ref_deltas; i++)
1352                sorted_by_pos[i] = &ref_deltas[i];
1353        QSORT(sorted_by_pos, nr_ref_deltas, delta_pos_compare);
1354
1355        if (has_promisor_remote()) {
1356                /*
1357                 * Prefetch the delta bases.
1358                 */
1359                struct oid_array to_fetch = OID_ARRAY_INIT;
1360                for (i = 0; i < nr_ref_deltas; i++) {
1361                        struct ref_delta_entry *d = sorted_by_pos[i];
1362                        if (!oid_object_info_extended(the_repository, &d->oid,
1363                                                      NULL,
1364                                                      OBJECT_INFO_FOR_PREFETCH))
1365                                continue;
1366                        oid_array_append(&to_fetch, &d->oid);
1367                }
1368                if (to_fetch.nr)
1369                        promisor_remote_get_direct(the_repository,
1370                                                   to_fetch.oid, to_fetch.nr);
1371                oid_array_clear(&to_fetch);
1372        }
1373
1374        for (i = 0; i < nr_ref_deltas; i++) {
1375                struct ref_delta_entry *d = sorted_by_pos[i];
1376                enum object_type type;
1377                struct base_data *base_obj = alloc_base_data();
1378
1379                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1380                        continue;
1381                base_obj->data = read_object_file(&d->oid, &type,
1382                                                  &base_obj->size);
1383                if (!base_obj->data)
1384                        continue;
1385
1386                if (check_object_signature(&d->oid, base_obj->data,
1387                                base_obj->size, type_name(type)))
1388                        die(_("local object %s is corrupt"), oid_to_hex(&d->oid));
1389                base_obj->obj = append_obj_to_pack(f, d->oid.hash,
1390                                        base_obj->data, base_obj->size, type);
1391                find_unresolved_deltas(base_obj);
1392                display_progress(progress, nr_resolved_deltas);
1393        }
1394        free(sorted_by_pos);
1395}
1396
1397static const char *derive_filename(const char *pack_name, const char *suffix,
1398                                   struct strbuf *buf)
1399{
1400        size_t len;
1401        if (!strip_suffix(pack_name, ".pack", &len))
1402                die(_("packfile name '%s' does not end with '.pack'"),
1403                    pack_name);
1404        strbuf_add(buf, pack_name, len);
1405        strbuf_addch(buf, '.');
1406        strbuf_addstr(buf, suffix);
1407        return buf->buf;
1408}
1409
1410static void write_special_file(const char *suffix, const char *msg,
1411                               const char *pack_name, const unsigned char *hash,
1412                               const char **report)
1413{
1414        struct strbuf name_buf = STRBUF_INIT;
1415        const char *filename;
1416        int fd;
1417        int msg_len = strlen(msg);
1418
1419        if (pack_name)
1420                filename = derive_filename(pack_name, suffix, &name_buf);
1421        else
1422                filename = odb_pack_name(&name_buf, hash, suffix);
1423
1424        fd = odb_pack_keep(filename);
1425        if (fd < 0) {
1426                if (errno != EEXIST)
1427                        die_errno(_("cannot write %s file '%s'"),
1428                                  suffix, filename);
1429        } else {
1430                if (msg_len > 0) {
1431                        write_or_die(fd, msg, msg_len);
1432                        write_or_die(fd, "\n", 1);
1433                }
1434                if (close(fd) != 0)
1435                        die_errno(_("cannot close written %s file '%s'"),
1436                                  suffix, filename);
1437                if (report)
1438                        *report = suffix;
1439        }
1440        strbuf_release(&name_buf);
1441}
1442
1443static void final(const char *final_pack_name, const char *curr_pack_name,
1444                  const char *final_index_name, const char *curr_index_name,
1445                  const char *keep_msg, const char *promisor_msg,
1446                  unsigned char *hash)
1447{
1448        const char *report = "pack";
1449        struct strbuf pack_name = STRBUF_INIT;
1450        struct strbuf index_name = STRBUF_INIT;
1451        int err;
1452
1453        if (!from_stdin) {
1454                close(input_fd);
1455        } else {
1456                fsync_or_die(output_fd, curr_pack_name);
1457                err = close(output_fd);
1458                if (err)
1459                        die_errno(_("error while closing pack file"));
1460        }
1461
1462        if (keep_msg)
1463                write_special_file("keep", keep_msg, final_pack_name, hash,
1464                                   &report);
1465        if (promisor_msg)
1466                write_special_file("promisor", promisor_msg, final_pack_name,
1467                                   hash, NULL);
1468
1469        if (final_pack_name != curr_pack_name) {
1470                if (!final_pack_name)
1471                        final_pack_name = odb_pack_name(&pack_name, hash, "pack");
1472                if (finalize_object_file(curr_pack_name, final_pack_name))
1473                        die(_("cannot store pack file"));
1474        } else if (from_stdin)
1475                chmod(final_pack_name, 0444);
1476
1477        if (final_index_name != curr_index_name) {
1478                if (!final_index_name)
1479                        final_index_name = odb_pack_name(&index_name, hash, "idx");
1480                if (finalize_object_file(curr_index_name, final_index_name))
1481                        die(_("cannot store index file"));
1482        } else
1483                chmod(final_index_name, 0444);
1484
1485        if (do_fsck_object) {
1486                struct packed_git *p;
1487                p = add_packed_git(final_index_name, strlen(final_index_name), 0);
1488                if (p)
1489                        install_packed_git(the_repository, p);
1490        }
1491
1492        if (!from_stdin) {
1493                printf("%s\n", sha1_to_hex(hash));
1494        } else {
1495                struct strbuf buf = STRBUF_INIT;
1496
1497                strbuf_addf(&buf, "%s\t%s\n", report, sha1_to_hex(hash));
1498                write_or_die(1, buf.buf, buf.len);
1499                strbuf_release(&buf);
1500
1501                /*
1502                 * Let's just mimic git-unpack-objects here and write
1503                 * the last part of the input buffer to stdout.
1504                 */
1505                while (input_len) {
1506                        err = xwrite(1, input_buffer + input_offset, input_len);
1507                        if (err <= 0)
1508                                break;
1509                        input_len -= err;
1510                        input_offset += err;
1511                }
1512        }
1513
1514        strbuf_release(&index_name);
1515        strbuf_release(&pack_name);
1516}
1517
1518static int git_index_pack_config(const char *k, const char *v, void *cb)
1519{
1520        struct pack_idx_option *opts = cb;
1521
1522        if (!strcmp(k, "pack.indexversion")) {
1523                opts->version = git_config_int(k, v);
1524                if (opts->version > 2)
1525                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1526                return 0;
1527        }
1528        if (!strcmp(k, "pack.threads")) {
1529                nr_threads = git_config_int(k, v);
1530                if (nr_threads < 0)
1531                        die(_("invalid number of threads specified (%d)"),
1532                            nr_threads);
1533                if (!HAVE_THREADS && nr_threads != 1) {
1534                        warning(_("no threads support, ignoring %s"), k);
1535                        nr_threads = 1;
1536                }
1537                return 0;
1538        }
1539        return git_default_config(k, v, cb);
1540}
1541
1542static int cmp_uint32(const void *a_, const void *b_)
1543{
1544        uint32_t a = *((uint32_t *)a_);
1545        uint32_t b = *((uint32_t *)b_);
1546
1547        return (a < b) ? -1 : (a != b);
1548}
1549
1550static void read_v2_anomalous_offsets(struct packed_git *p,
1551                                      struct pack_idx_option *opts)
1552{
1553        const uint32_t *idx1, *idx2;
1554        uint32_t i;
1555        const uint32_t hashwords = the_hash_algo->rawsz / sizeof(uint32_t);
1556
1557        /* The address of the 4-byte offset table */
1558        idx1 = (((const uint32_t *)p->index_data)
1559                + 2 /* 8-byte header */
1560                + 256 /* fan out */
1561                + hashwords * p->num_objects /* object ID table */
1562                + p->num_objects /* CRC32 table */
1563                );
1564
1565        /* The address of the 8-byte offset table */
1566        idx2 = idx1 + p->num_objects;
1567
1568        for (i = 0; i < p->num_objects; i++) {
1569                uint32_t off = ntohl(idx1[i]);
1570                if (!(off & 0x80000000))
1571                        continue;
1572                off = off & 0x7fffffff;
1573                check_pack_index_ptr(p, &idx2[off * 2]);
1574                if (idx2[off * 2])
1575                        continue;
1576                /*
1577                 * The real offset is ntohl(idx2[off * 2]) in high 4
1578                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1579                 * octets.  But idx2[off * 2] is Zero!!!
1580                 */
1581                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1582                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1583        }
1584
1585        QSORT(opts->anomaly, opts->anomaly_nr, cmp_uint32);
1586}
1587
1588static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1589{
1590        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1591
1592        if (!p)
1593                die(_("Cannot open existing pack file '%s'"), pack_name);
1594        if (open_pack_index(p))
1595                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1596
1597        /* Read the attributes from the existing idx file */
1598        opts->version = p->index_version;
1599
1600        if (opts->version == 2)
1601                read_v2_anomalous_offsets(p, opts);
1602
1603        /*
1604         * Get rid of the idx file as we do not need it anymore.
1605         * NEEDSWORK: extract this bit from free_pack_by_name() in
1606         * sha1-file.c, perhaps?  It shouldn't matter very much as we
1607         * know we haven't installed this pack (hence we never have
1608         * read anything from it).
1609         */
1610        close_pack_index(p);
1611        free(p);
1612}
1613
1614static void show_pack_info(int stat_only)
1615{
1616        int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1617        unsigned long *chain_histogram = NULL;
1618
1619        if (deepest_delta)
1620                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1621
1622        for (i = 0; i < nr_objects; i++) {
1623                struct object_entry *obj = &objects[i];
1624
1625                if (is_delta_type(obj->type))
1626                        chain_histogram[obj_stat[i].delta_depth - 1]++;
1627                if (stat_only)
1628                        continue;
1629                printf("%s %-6s %"PRIuMAX" %"PRIuMAX" %"PRIuMAX,
1630                       oid_to_hex(&obj->idx.oid),
1631                       type_name(obj->real_type), (uintmax_t)obj->size,
1632                       (uintmax_t)(obj[1].idx.offset - obj->idx.offset),
1633                       (uintmax_t)obj->idx.offset);
1634                if (is_delta_type(obj->type)) {
1635                        struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1636                        printf(" %u %s", obj_stat[i].delta_depth,
1637                               oid_to_hex(&bobj->idx.oid));
1638                }
1639                putchar('\n');
1640        }
1641
1642        if (baseobjects)
1643                printf_ln(Q_("non delta: %d object",
1644                             "non delta: %d objects",
1645                             baseobjects),
1646                          baseobjects);
1647        for (i = 0; i < deepest_delta; i++) {
1648                if (!chain_histogram[i])
1649                        continue;
1650                printf_ln(Q_("chain length = %d: %lu object",
1651                             "chain length = %d: %lu objects",
1652                             chain_histogram[i]),
1653                          i + 1,
1654                          chain_histogram[i]);
1655        }
1656}
1657
1658int cmd_index_pack(int argc, const char **argv, const char *prefix)
1659{
1660        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1661        const char *curr_index;
1662        const char *index_name = NULL, *pack_name = NULL;
1663        const char *keep_msg = NULL;
1664        const char *promisor_msg = NULL;
1665        struct strbuf index_name_buf = STRBUF_INIT;
1666        struct pack_idx_entry **idx_objects;
1667        struct pack_idx_option opts;
1668        unsigned char pack_hash[GIT_MAX_RAWSZ];
1669        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1670        int report_end_of_input = 0;
1671
1672        /*
1673         * index-pack never needs to fetch missing objects except when
1674         * REF_DELTA bases are missing (which are explicitly handled). It only
1675         * accesses the repo to do hash collision checks and to check which
1676         * REF_DELTA bases need to be fetched.
1677         */
1678        fetch_if_missing = 0;
1679
1680        if (argc == 2 && !strcmp(argv[1], "-h"))
1681                usage(index_pack_usage);
1682
1683        read_replace_refs = 0;
1684        fsck_options.walk = mark_link;
1685
1686        reset_pack_idx_option(&opts);
1687        git_config(git_index_pack_config, &opts);
1688        if (prefix && chdir(prefix))
1689                die(_("Cannot come back to cwd"));
1690
1691        for (i = 1; i < argc; i++) {
1692                const char *arg = argv[i];
1693
1694                if (*arg == '-') {
1695                        if (!strcmp(arg, "--stdin")) {
1696                                from_stdin = 1;
1697                        } else if (!strcmp(arg, "--fix-thin")) {
1698                                fix_thin_pack = 1;
1699                        } else if (skip_to_optional_arg(arg, "--strict", &arg)) {
1700                                strict = 1;
1701                                do_fsck_object = 1;
1702                                fsck_set_msg_types(&fsck_options, arg);
1703                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1704                                strict = 1;
1705                                check_self_contained_and_connected = 1;
1706                        } else if (!strcmp(arg, "--fsck-objects")) {
1707                                do_fsck_object = 1;
1708                        } else if (!strcmp(arg, "--verify")) {
1709                                verify = 1;
1710                        } else if (!strcmp(arg, "--verify-stat")) {
1711                                verify = 1;
1712                                show_stat = 1;
1713                        } else if (!strcmp(arg, "--verify-stat-only")) {
1714                                verify = 1;
1715                                show_stat = 1;
1716                                stat_only = 1;
1717                        } else if (skip_to_optional_arg(arg, "--keep", &keep_msg)) {
1718                                ; /* nothing to do */
1719                        } else if (skip_to_optional_arg(arg, "--promisor", &promisor_msg)) {
1720                                ; /* already parsed */
1721                        } else if (starts_with(arg, "--threads=")) {
1722                                char *end;
1723                                nr_threads = strtoul(arg+10, &end, 0);
1724                                if (!arg[10] || *end || nr_threads < 0)
1725                                        usage(index_pack_usage);
1726                                if (!HAVE_THREADS && nr_threads != 1) {
1727                                        warning(_("no threads support, ignoring %s"), arg);
1728                                        nr_threads = 1;
1729                                }
1730                        } else if (starts_with(arg, "--pack_header=")) {
1731                                struct pack_header *hdr;
1732                                char *c;
1733
1734                                hdr = (struct pack_header *)input_buffer;
1735                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1736                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1737                                if (*c != ',')
1738                                        die(_("bad %s"), arg);
1739                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1740                                if (*c)
1741                                        die(_("bad %s"), arg);
1742                                input_len = sizeof(*hdr);
1743                        } else if (!strcmp(arg, "-v")) {
1744                                verbose = 1;
1745                        } else if (!strcmp(arg, "--show-resolving-progress")) {
1746                                show_resolving_progress = 1;
1747                        } else if (!strcmp(arg, "--report-end-of-input")) {
1748                                report_end_of_input = 1;
1749                        } else if (!strcmp(arg, "-o")) {
1750                                if (index_name || (i+1) >= argc)
1751                                        usage(index_pack_usage);
1752                                index_name = argv[++i];
1753                        } else if (starts_with(arg, "--index-version=")) {
1754                                char *c;
1755                                opts.version = strtoul(arg + 16, &c, 10);
1756                                if (opts.version > 2)
1757                                        die(_("bad %s"), arg);
1758                                if (*c == ',')
1759                                        opts.off32_limit = strtoul(c+1, &c, 0);
1760                                if (*c || opts.off32_limit & 0x80000000)
1761                                        die(_("bad %s"), arg);
1762                        } else if (skip_prefix(arg, "--max-input-size=", &arg)) {
1763                                max_input_size = strtoumax(arg, NULL, 10);
1764                        } else
1765                                usage(index_pack_usage);
1766                        continue;
1767                }
1768
1769                if (pack_name)
1770                        usage(index_pack_usage);
1771                pack_name = arg;
1772        }
1773
1774        if (!pack_name && !from_stdin)
1775                usage(index_pack_usage);
1776        if (fix_thin_pack && !from_stdin)
1777                die(_("--fix-thin cannot be used without --stdin"));
1778        if (from_stdin && !startup_info->have_repository)
1779                die(_("--stdin requires a git repository"));
1780        if (!index_name && pack_name)
1781                index_name = derive_filename(pack_name, "idx", &index_name_buf);
1782
1783        if (verify) {
1784                if (!index_name)
1785                        die(_("--verify with no packfile name given"));
1786                read_idx_option(&opts, index_name);
1787                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1788        }
1789        if (strict)
1790                opts.flags |= WRITE_IDX_STRICT;
1791
1792        if (HAVE_THREADS && !nr_threads) {
1793                nr_threads = online_cpus();
1794                /* An experiment showed that more threads does not mean faster */
1795                if (nr_threads > 3)
1796                        nr_threads = 3;
1797        }
1798
1799        curr_pack = open_pack_file(pack_name);
1800        parse_pack_header();
1801        objects = xcalloc(st_add(nr_objects, 1), sizeof(struct object_entry));
1802        if (show_stat)
1803                obj_stat = xcalloc(st_add(nr_objects, 1), sizeof(struct object_stat));
1804        ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
1805        parse_pack_objects(pack_hash);
1806        if (report_end_of_input)
1807                write_in_full(2, "\0", 1);
1808        resolve_deltas();
1809        conclude_pack(fix_thin_pack, curr_pack, pack_hash);
1810        free(ofs_deltas);
1811        free(ref_deltas);
1812        if (strict)
1813                foreign_nr = check_objects();
1814
1815        if (show_stat)
1816                show_pack_info(stat_only);
1817
1818        ALLOC_ARRAY(idx_objects, nr_objects);
1819        for (i = 0; i < nr_objects; i++)
1820                idx_objects[i] = &objects[i].idx;
1821        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_hash);
1822        free(idx_objects);
1823
1824        if (!verify)
1825                final(pack_name, curr_pack,
1826                      index_name, curr_index,
1827                      keep_msg, promisor_msg,
1828                      pack_hash);
1829        else
1830                close(input_fd);
1831
1832        if (do_fsck_object && fsck_finish(&fsck_options))
1833                die(_("fsck error in pack objects"));
1834
1835        free(objects);
1836        strbuf_release(&index_name_buf);
1837        if (pack_name == NULL)
1838                free((void *) curr_pack);
1839        if (index_name == NULL)
1840                free((void *) curr_index);
1841
1842        /*
1843         * Let the caller know this pack is not self contained
1844         */
1845        if (check_self_contained_and_connected && foreign_nr)
1846                return 1;
1847
1848        return 0;
1849}