builtin / index-pack.con commit builtin rebase: support `fork-point` option (92d0d74)
   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#ifndef NO_PTHREADS
  46        pthread_t thread;
  47#endif
  48        struct base_data *base_cache;
  49        size_t base_cache_used;
  50        int pack_fd;
  51};
  52
  53/* Remember to update object flag allocation in object.h */
  54#define FLAG_LINK (1u<<20)
  55#define FLAG_CHECKED (1u<<21)
  56
  57struct ofs_delta_entry {
  58        off_t offset;
  59        int obj_no;
  60};
  61
  62struct ref_delta_entry {
  63        struct object_id oid;
  64        int obj_no;
  65};
  66
  67static struct object_entry *objects;
  68static struct object_stat *obj_stat;
  69static struct ofs_delta_entry *ofs_deltas;
  70static struct ref_delta_entry *ref_deltas;
  71static struct thread_local nothread_data;
  72static int nr_objects;
  73static int nr_ofs_deltas;
  74static int nr_ref_deltas;
  75static int ref_deltas_alloc;
  76static int nr_resolved_deltas;
  77static int nr_threads;
  78
  79static int from_stdin;
  80static int strict;
  81static int do_fsck_object;
  82static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
  83static int verbose;
  84static int show_resolving_progress;
  85static int show_stat;
  86static int check_self_contained_and_connected;
  87
  88static struct progress *progress;
  89
  90/* We always read in 4kB chunks. */
  91static unsigned char input_buffer[4096];
  92static unsigned int input_offset, input_len;
  93static off_t consumed_bytes;
  94static off_t max_input_size;
  95static unsigned deepest_delta;
  96static git_hash_ctx input_ctx;
  97static uint32_t input_crc32;
  98static int input_fd, output_fd;
  99static const char *curr_pack;
 100
 101#ifndef NO_PTHREADS
 102
 103static struct thread_local *thread_data;
 104static int nr_dispatched;
 105static int threads_active;
 106
 107static pthread_mutex_t read_mutex;
 108#define read_lock()             lock_mutex(&read_mutex)
 109#define read_unlock()           unlock_mutex(&read_mutex)
 110
 111static pthread_mutex_t counter_mutex;
 112#define counter_lock()          lock_mutex(&counter_mutex)
 113#define counter_unlock()        unlock_mutex(&counter_mutex)
 114
 115static pthread_mutex_t work_mutex;
 116#define work_lock()             lock_mutex(&work_mutex)
 117#define work_unlock()           unlock_mutex(&work_mutex)
 118
 119static pthread_mutex_t deepest_delta_mutex;
 120#define deepest_delta_lock()    lock_mutex(&deepest_delta_mutex)
 121#define deepest_delta_unlock()  unlock_mutex(&deepest_delta_mutex)
 122
 123static pthread_mutex_t type_cas_mutex;
 124#define type_cas_lock()         lock_mutex(&type_cas_mutex)
 125#define type_cas_unlock()       unlock_mutex(&type_cas_mutex)
 126
 127static pthread_key_t key;
 128
 129static inline void lock_mutex(pthread_mutex_t *mutex)
 130{
 131        if (threads_active)
 132                pthread_mutex_lock(mutex);
 133}
 134
 135static inline void unlock_mutex(pthread_mutex_t *mutex)
 136{
 137        if (threads_active)
 138                pthread_mutex_unlock(mutex);
 139}
 140
 141/*
 142 * Mutex and conditional variable can't be statically-initialized on Windows.
 143 */
 144static void init_thread(void)
 145{
 146        int i;
 147        init_recursive_mutex(&read_mutex);
 148        pthread_mutex_init(&counter_mutex, NULL);
 149        pthread_mutex_init(&work_mutex, NULL);
 150        pthread_mutex_init(&type_cas_mutex, NULL);
 151        if (show_stat)
 152                pthread_mutex_init(&deepest_delta_mutex, NULL);
 153        pthread_key_create(&key, NULL);
 154        thread_data = xcalloc(nr_threads, sizeof(*thread_data));
 155        for (i = 0; i < nr_threads; i++) {
 156                thread_data[i].pack_fd = open(curr_pack, O_RDONLY);
 157                if (thread_data[i].pack_fd == -1)
 158                        die_errno(_("unable to open %s"), curr_pack);
 159        }
 160
 161        threads_active = 1;
 162}
 163
 164static void cleanup_thread(void)
 165{
 166        int i;
 167        if (!threads_active)
 168                return;
 169        threads_active = 0;
 170        pthread_mutex_destroy(&read_mutex);
 171        pthread_mutex_destroy(&counter_mutex);
 172        pthread_mutex_destroy(&work_mutex);
 173        pthread_mutex_destroy(&type_cas_mutex);
 174        if (show_stat)
 175                pthread_mutex_destroy(&deepest_delta_mutex);
 176        for (i = 0; i < nr_threads; i++)
 177                close(thread_data[i].pack_fd);
 178        pthread_key_delete(key);
 179        free(thread_data);
 180}
 181
 182#else
 183
 184#define read_lock()
 185#define read_unlock()
 186
 187#define counter_lock()
 188#define counter_unlock()
 189
 190#define work_lock()
 191#define work_unlock()
 192
 193#define deepest_delta_lock()
 194#define deepest_delta_unlock()
 195
 196#define type_cas_lock()
 197#define type_cas_unlock()
 198
 199#endif
 200
 201
 202static int mark_link(struct object *obj, int type, void *data, struct fsck_options *options)
 203{
 204        if (!obj)
 205                return -1;
 206
 207        if (type != OBJ_ANY && obj->type != type)
 208                die(_("object type mismatch at %s"), oid_to_hex(&obj->oid));
 209
 210        obj->flags |= FLAG_LINK;
 211        return 0;
 212}
 213
 214/* The content of each linked object must have been checked
 215   or it must be already present in the object database */
 216static unsigned check_object(struct object *obj)
 217{
 218        if (!obj)
 219                return 0;
 220
 221        if (!(obj->flags & FLAG_LINK))
 222                return 0;
 223
 224        if (!(obj->flags & FLAG_CHECKED)) {
 225                unsigned long size;
 226                int type = oid_object_info(the_repository, &obj->oid, &size);
 227                if (type <= 0)
 228                        die(_("did not receive expected object %s"),
 229                              oid_to_hex(&obj->oid));
 230                if (type != obj->type)
 231                        die(_("object %s: expected type %s, found %s"),
 232                            oid_to_hex(&obj->oid),
 233                            type_name(obj->type), type_name(type));
 234                obj->flags |= FLAG_CHECKED;
 235                return 1;
 236        }
 237
 238        return 0;
 239}
 240
 241static unsigned check_objects(void)
 242{
 243        unsigned i, max, foreign_nr = 0;
 244
 245        max = get_max_object_index();
 246        for (i = 0; i < max; i++)
 247                foreign_nr += check_object(get_indexed_object(i));
 248        return foreign_nr;
 249}
 250
 251
 252/* Discard current buffer used content. */
 253static void flush(void)
 254{
 255        if (input_offset) {
 256                if (output_fd >= 0)
 257                        write_or_die(output_fd, input_buffer, input_offset);
 258                the_hash_algo->update_fn(&input_ctx, input_buffer, input_offset);
 259                memmove(input_buffer, input_buffer + input_offset, input_len);
 260                input_offset = 0;
 261        }
 262}
 263
 264/*
 265 * Make sure at least "min" bytes are available in the buffer, and
 266 * return the pointer to the buffer.
 267 */
 268static void *fill(int min)
 269{
 270        if (min <= input_len)
 271                return input_buffer + input_offset;
 272        if (min > sizeof(input_buffer))
 273                die(Q_("cannot fill %d byte",
 274                       "cannot fill %d bytes",
 275                       min),
 276                    min);
 277        flush();
 278        do {
 279                ssize_t ret = xread(input_fd, input_buffer + input_len,
 280                                sizeof(input_buffer) - input_len);
 281                if (ret <= 0) {
 282                        if (!ret)
 283                                die(_("early EOF"));
 284                        die_errno(_("read error on input"));
 285                }
 286                input_len += ret;
 287                if (from_stdin)
 288                        display_throughput(progress, consumed_bytes + input_len);
 289        } while (input_len < min);
 290        return input_buffer;
 291}
 292
 293static void use(int bytes)
 294{
 295        if (bytes > input_len)
 296                die(_("used more bytes than were available"));
 297        input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
 298        input_len -= bytes;
 299        input_offset += bytes;
 300
 301        /* make sure off_t is sufficiently large not to wrap */
 302        if (signed_add_overflows(consumed_bytes, bytes))
 303                die(_("pack too large for current definition of off_t"));
 304        consumed_bytes += bytes;
 305        if (max_input_size && consumed_bytes > max_input_size)
 306                die(_("pack exceeds maximum allowed size"));
 307}
 308
 309static const char *open_pack_file(const char *pack_name)
 310{
 311        if (from_stdin) {
 312                input_fd = 0;
 313                if (!pack_name) {
 314                        struct strbuf tmp_file = STRBUF_INIT;
 315                        output_fd = odb_mkstemp(&tmp_file,
 316                                                "pack/tmp_pack_XXXXXX");
 317                        pack_name = strbuf_detach(&tmp_file, NULL);
 318                } else {
 319                        output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
 320                        if (output_fd < 0)
 321                                die_errno(_("unable to create '%s'"), pack_name);
 322                }
 323                nothread_data.pack_fd = output_fd;
 324        } else {
 325                input_fd = open(pack_name, O_RDONLY);
 326                if (input_fd < 0)
 327                        die_errno(_("cannot open packfile '%s'"), pack_name);
 328                output_fd = -1;
 329                nothread_data.pack_fd = input_fd;
 330        }
 331        the_hash_algo->init_fn(&input_ctx);
 332        return pack_name;
 333}
 334
 335static void parse_pack_header(void)
 336{
 337        struct pack_header *hdr = fill(sizeof(struct pack_header));
 338
 339        /* Header consistency check */
 340        if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 341                die(_("pack signature mismatch"));
 342        if (!pack_version_ok(hdr->hdr_version))
 343                die(_("pack version %"PRIu32" unsupported"),
 344                        ntohl(hdr->hdr_version));
 345
 346        nr_objects = ntohl(hdr->hdr_entries);
 347        use(sizeof(struct pack_header));
 348}
 349
 350static NORETURN void bad_object(off_t offset, const char *format,
 351                       ...) __attribute__((format (printf, 2, 3)));
 352
 353static NORETURN void bad_object(off_t offset, const char *format, ...)
 354{
 355        va_list params;
 356        char buf[1024];
 357
 358        va_start(params, format);
 359        vsnprintf(buf, sizeof(buf), format, params);
 360        va_end(params);
 361        die(_("pack has bad object at offset %"PRIuMAX": %s"),
 362            (uintmax_t)offset, buf);
 363}
 364
 365static inline struct thread_local *get_thread_data(void)
 366{
 367#ifndef NO_PTHREADS
 368        if (threads_active)
 369                return pthread_getspecific(key);
 370        assert(!threads_active &&
 371               "This should only be reached when all threads are gone");
 372#endif
 373        return &nothread_data;
 374}
 375
 376#ifndef NO_PTHREADS
 377static void set_thread_data(struct thread_local *data)
 378{
 379        if (threads_active)
 380                pthread_setspecific(key, data);
 381}
 382#endif
 383
 384static struct base_data *alloc_base_data(void)
 385{
 386        struct base_data *base = xcalloc(1, sizeof(struct base_data));
 387        base->ref_last = -1;
 388        base->ofs_last = -1;
 389        return base;
 390}
 391
 392static void free_base_data(struct base_data *c)
 393{
 394        if (c->data) {
 395                FREE_AND_NULL(c->data);
 396                get_thread_data()->base_cache_used -= c->size;
 397        }
 398}
 399
 400static void prune_base_data(struct base_data *retain)
 401{
 402        struct base_data *b;
 403        struct thread_local *data = get_thread_data();
 404        for (b = data->base_cache;
 405             data->base_cache_used > delta_base_cache_limit && b;
 406             b = b->child) {
 407                if (b->data && b != retain)
 408                        free_base_data(b);
 409        }
 410}
 411
 412static void link_base_data(struct base_data *base, struct base_data *c)
 413{
 414        if (base)
 415                base->child = c;
 416        else
 417                get_thread_data()->base_cache = c;
 418
 419        c->base = base;
 420        c->child = NULL;
 421        if (c->data)
 422                get_thread_data()->base_cache_used += c->size;
 423        prune_base_data(c);
 424}
 425
 426static void unlink_base_data(struct base_data *c)
 427{
 428        struct base_data *base = c->base;
 429        if (base)
 430                base->child = NULL;
 431        else
 432                get_thread_data()->base_cache = NULL;
 433        free_base_data(c);
 434}
 435
 436static int is_delta_type(enum object_type type)
 437{
 438        return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
 439}
 440
 441static void *unpack_entry_data(off_t offset, unsigned long size,
 442                               enum object_type type, struct object_id *oid)
 443{
 444        static char fixed_buf[8192];
 445        int status;
 446        git_zstream stream;
 447        void *buf;
 448        git_hash_ctx c;
 449        char hdr[32];
 450        int hdrlen;
 451
 452        if (!is_delta_type(type)) {
 453                hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(type), size) + 1;
 454                the_hash_algo->init_fn(&c);
 455                the_hash_algo->update_fn(&c, hdr, hdrlen);
 456        } else
 457                oid = NULL;
 458        if (type == OBJ_BLOB && size > big_file_threshold)
 459                buf = fixed_buf;
 460        else
 461                buf = xmallocz(size);
 462
 463        memset(&stream, 0, sizeof(stream));
 464        git_inflate_init(&stream);
 465        stream.next_out = buf;
 466        stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
 467
 468        do {
 469                unsigned char *last_out = stream.next_out;
 470                stream.next_in = fill(1);
 471                stream.avail_in = input_len;
 472                status = git_inflate(&stream, 0);
 473                use(input_len - stream.avail_in);
 474                if (oid)
 475                        the_hash_algo->update_fn(&c, last_out, stream.next_out - last_out);
 476                if (buf == fixed_buf) {
 477                        stream.next_out = buf;
 478                        stream.avail_out = sizeof(fixed_buf);
 479                }
 480        } while (status == Z_OK);
 481        if (stream.total_out != size || status != Z_STREAM_END)
 482                bad_object(offset, _("inflate returned %d"), status);
 483        git_inflate_end(&stream);
 484        if (oid)
 485                the_hash_algo->final_fn(oid->hash, &c);
 486        return buf == fixed_buf ? NULL : buf;
 487}
 488
 489static void *unpack_raw_entry(struct object_entry *obj,
 490                              off_t *ofs_offset,
 491                              struct object_id *ref_oid,
 492                              struct object_id *oid)
 493{
 494        unsigned char *p;
 495        unsigned long size, c;
 496        off_t base_offset;
 497        unsigned shift;
 498        void *data;
 499
 500        obj->idx.offset = consumed_bytes;
 501        input_crc32 = crc32(0, NULL, 0);
 502
 503        p = fill(1);
 504        c = *p;
 505        use(1);
 506        obj->type = (c >> 4) & 7;
 507        size = (c & 15);
 508        shift = 4;
 509        while (c & 0x80) {
 510                p = fill(1);
 511                c = *p;
 512                use(1);
 513                size += (c & 0x7f) << shift;
 514                shift += 7;
 515        }
 516        obj->size = size;
 517
 518        switch (obj->type) {
 519        case OBJ_REF_DELTA:
 520                hashcpy(ref_oid->hash, fill(the_hash_algo->rawsz));
 521                use(the_hash_algo->rawsz);
 522                break;
 523        case OBJ_OFS_DELTA:
 524                p = fill(1);
 525                c = *p;
 526                use(1);
 527                base_offset = c & 127;
 528                while (c & 128) {
 529                        base_offset += 1;
 530                        if (!base_offset || MSB(base_offset, 7))
 531                                bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
 532                        p = fill(1);
 533                        c = *p;
 534                        use(1);
 535                        base_offset = (base_offset << 7) + (c & 127);
 536                }
 537                *ofs_offset = obj->idx.offset - base_offset;
 538                if (*ofs_offset <= 0 || *ofs_offset >= obj->idx.offset)
 539                        bad_object(obj->idx.offset, _("delta base offset is out of bound"));
 540                break;
 541        case OBJ_COMMIT:
 542        case OBJ_TREE:
 543        case OBJ_BLOB:
 544        case OBJ_TAG:
 545                break;
 546        default:
 547                bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
 548        }
 549        obj->hdr_size = consumed_bytes - obj->idx.offset;
 550
 551        data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, oid);
 552        obj->idx.crc32 = input_crc32;
 553        return data;
 554}
 555
 556static void *unpack_data(struct object_entry *obj,
 557                         int (*consume)(const unsigned char *, unsigned long, void *),
 558                         void *cb_data)
 559{
 560        off_t from = obj[0].idx.offset + obj[0].hdr_size;
 561        off_t len = obj[1].idx.offset - from;
 562        unsigned char *data, *inbuf;
 563        git_zstream stream;
 564        int status;
 565
 566        data = xmallocz(consume ? 64*1024 : obj->size);
 567        inbuf = xmalloc((len < 64*1024) ? (int)len : 64*1024);
 568
 569        memset(&stream, 0, sizeof(stream));
 570        git_inflate_init(&stream);
 571        stream.next_out = data;
 572        stream.avail_out = consume ? 64*1024 : obj->size;
 573
 574        do {
 575                ssize_t n = (len < 64*1024) ? (ssize_t)len : 64*1024;
 576                n = xpread(get_thread_data()->pack_fd, inbuf, n, from);
 577                if (n < 0)
 578                        die_errno(_("cannot pread pack file"));
 579                if (!n)
 580                        die(Q_("premature end of pack file, %"PRIuMAX" byte missing",
 581                               "premature end of pack file, %"PRIuMAX" bytes missing",
 582                               (unsigned int)len),
 583                            (uintmax_t)len);
 584                from += n;
 585                len -= n;
 586                stream.next_in = inbuf;
 587                stream.avail_in = n;
 588                if (!consume)
 589                        status = git_inflate(&stream, 0);
 590                else {
 591                        do {
 592                                status = git_inflate(&stream, 0);
 593                                if (consume(data, stream.next_out - data, cb_data)) {
 594                                        free(inbuf);
 595                                        free(data);
 596                                        return NULL;
 597                                }
 598                                stream.next_out = data;
 599                                stream.avail_out = 64*1024;
 600                        } while (status == Z_OK && stream.avail_in);
 601                }
 602        } while (len && status == Z_OK && !stream.avail_in);
 603
 604        /* This has been inflated OK when first encountered, so... */
 605        if (status != Z_STREAM_END || stream.total_out != obj->size)
 606                die(_("serious inflate inconsistency"));
 607
 608        git_inflate_end(&stream);
 609        free(inbuf);
 610        if (consume) {
 611                FREE_AND_NULL(data);
 612        }
 613        return data;
 614}
 615
 616static void *get_data_from_pack(struct object_entry *obj)
 617{
 618        return unpack_data(obj, NULL, NULL);
 619}
 620
 621static int compare_ofs_delta_bases(off_t offset1, off_t offset2,
 622                                   enum object_type type1,
 623                                   enum object_type type2)
 624{
 625        int cmp = type1 - type2;
 626        if (cmp)
 627                return cmp;
 628        return offset1 < offset2 ? -1 :
 629               offset1 > offset2 ?  1 :
 630               0;
 631}
 632
 633static int find_ofs_delta(const off_t offset, enum object_type type)
 634{
 635        int first = 0, last = nr_ofs_deltas;
 636
 637        while (first < last) {
 638                int next = first + (last - first) / 2;
 639                struct ofs_delta_entry *delta = &ofs_deltas[next];
 640                int cmp;
 641
 642                cmp = compare_ofs_delta_bases(offset, delta->offset,
 643                                              type, objects[delta->obj_no].type);
 644                if (!cmp)
 645                        return next;
 646                if (cmp < 0) {
 647                        last = next;
 648                        continue;
 649                }
 650                first = next+1;
 651        }
 652        return -first-1;
 653}
 654
 655static void find_ofs_delta_children(off_t offset,
 656                                    int *first_index, int *last_index,
 657                                    enum object_type type)
 658{
 659        int first = find_ofs_delta(offset, type);
 660        int last = first;
 661        int end = nr_ofs_deltas - 1;
 662
 663        if (first < 0) {
 664                *first_index = 0;
 665                *last_index = -1;
 666                return;
 667        }
 668        while (first > 0 && ofs_deltas[first - 1].offset == offset)
 669                --first;
 670        while (last < end && ofs_deltas[last + 1].offset == offset)
 671                ++last;
 672        *first_index = first;
 673        *last_index = last;
 674}
 675
 676static int compare_ref_delta_bases(const struct object_id *oid1,
 677                                   const struct object_id *oid2,
 678                                   enum object_type type1,
 679                                   enum object_type type2)
 680{
 681        int cmp = type1 - type2;
 682        if (cmp)
 683                return cmp;
 684        return oidcmp(oid1, oid2);
 685}
 686
 687static int find_ref_delta(const struct object_id *oid, enum object_type type)
 688{
 689        int first = 0, last = nr_ref_deltas;
 690
 691        while (first < last) {
 692                int next = first + (last - first) / 2;
 693                struct ref_delta_entry *delta = &ref_deltas[next];
 694                int cmp;
 695
 696                cmp = compare_ref_delta_bases(oid, &delta->oid,
 697                                              type, objects[delta->obj_no].type);
 698                if (!cmp)
 699                        return next;
 700                if (cmp < 0) {
 701                        last = next;
 702                        continue;
 703                }
 704                first = next+1;
 705        }
 706        return -first-1;
 707}
 708
 709static void find_ref_delta_children(const struct object_id *oid,
 710                                    int *first_index, int *last_index,
 711                                    enum object_type type)
 712{
 713        int first = find_ref_delta(oid, type);
 714        int last = first;
 715        int end = nr_ref_deltas - 1;
 716
 717        if (first < 0) {
 718                *first_index = 0;
 719                *last_index = -1;
 720                return;
 721        }
 722        while (first > 0 && !oidcmp(&ref_deltas[first - 1].oid, oid))
 723                --first;
 724        while (last < end && !oidcmp(&ref_deltas[last + 1].oid, oid))
 725                ++last;
 726        *first_index = first;
 727        *last_index = last;
 728}
 729
 730struct compare_data {
 731        struct object_entry *entry;
 732        struct git_istream *st;
 733        unsigned char *buf;
 734        unsigned long buf_size;
 735};
 736
 737static int compare_objects(const unsigned char *buf, unsigned long size,
 738                           void *cb_data)
 739{
 740        struct compare_data *data = cb_data;
 741
 742        if (data->buf_size < size) {
 743                free(data->buf);
 744                data->buf = xmalloc(size);
 745                data->buf_size = size;
 746        }
 747
 748        while (size) {
 749                ssize_t len = read_istream(data->st, data->buf, size);
 750                if (len == 0)
 751                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 752                            oid_to_hex(&data->entry->idx.oid));
 753                if (len < 0)
 754                        die(_("unable to read %s"),
 755                            oid_to_hex(&data->entry->idx.oid));
 756                if (memcmp(buf, data->buf, len))
 757                        die(_("SHA1 COLLISION FOUND WITH %s !"),
 758                            oid_to_hex(&data->entry->idx.oid));
 759                size -= len;
 760                buf += len;
 761        }
 762        return 0;
 763}
 764
 765static int check_collison(struct object_entry *entry)
 766{
 767        struct compare_data data;
 768        enum object_type type;
 769        unsigned long size;
 770
 771        if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
 772                return -1;
 773
 774        memset(&data, 0, sizeof(data));
 775        data.entry = entry;
 776        data.st = open_istream(&entry->idx.oid, &type, &size, NULL);
 777        if (!data.st)
 778                return -1;
 779        if (size != entry->size || type != entry->type)
 780                die(_("SHA1 COLLISION FOUND WITH %s !"),
 781                    oid_to_hex(&entry->idx.oid));
 782        unpack_data(entry, compare_objects, &data);
 783        close_istream(data.st);
 784        free(data.buf);
 785        return 0;
 786}
 787
 788static void sha1_object(const void *data, struct object_entry *obj_entry,
 789                        unsigned long size, enum object_type type,
 790                        const struct object_id *oid)
 791{
 792        void *new_data = NULL;
 793        int collision_test_needed = 0;
 794
 795        assert(data || obj_entry);
 796
 797        if (startup_info->have_repository) {
 798                read_lock();
 799                collision_test_needed =
 800                        has_sha1_file_with_flags(oid->hash, OBJECT_INFO_QUICK);
 801                read_unlock();
 802        }
 803
 804        if (collision_test_needed && !data) {
 805                read_lock();
 806                if (!check_collison(obj_entry))
 807                        collision_test_needed = 0;
 808                read_unlock();
 809        }
 810        if (collision_test_needed) {
 811                void *has_data;
 812                enum object_type has_type;
 813                unsigned long has_size;
 814                read_lock();
 815                has_type = oid_object_info(the_repository, oid, &has_size);
 816                if (has_type < 0)
 817                        die(_("cannot read existing object info %s"), oid_to_hex(oid));
 818                if (has_type != type || has_size != size)
 819                        die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 820                has_data = read_object_file(oid, &has_type, &has_size);
 821                read_unlock();
 822                if (!data)
 823                        data = new_data = get_data_from_pack(obj_entry);
 824                if (!has_data)
 825                        die(_("cannot read existing object %s"), oid_to_hex(oid));
 826                if (size != has_size || type != has_type ||
 827                    memcmp(data, has_data, size) != 0)
 828                        die(_("SHA1 COLLISION FOUND WITH %s !"), oid_to_hex(oid));
 829                free(has_data);
 830        }
 831
 832        if (strict || do_fsck_object) {
 833                read_lock();
 834                if (type == OBJ_BLOB) {
 835                        struct blob *blob = lookup_blob(the_repository, oid);
 836                        if (blob)
 837                                blob->object.flags |= FLAG_CHECKED;
 838                        else
 839                                die(_("invalid blob object %s"), oid_to_hex(oid));
 840                        if (do_fsck_object &&
 841                            fsck_object(&blob->object, (void *)data, size, &fsck_options))
 842                                die(_("fsck error in packed object"));
 843                } else {
 844                        struct object *obj;
 845                        int eaten;
 846                        void *buf = (void *) data;
 847
 848                        assert(data && "data can only be NULL for large _blobs_");
 849
 850                        /*
 851                         * we do not need to free the memory here, as the
 852                         * buf is deleted by the caller.
 853                         */
 854                        obj = parse_object_buffer(the_repository, oid, type,
 855                                                  size, buf,
 856                                                  &eaten);
 857                        if (!obj)
 858                                die(_("invalid %s"), type_name(type));
 859                        if (do_fsck_object &&
 860                            fsck_object(obj, buf, size, &fsck_options))
 861                                die(_("fsck error in packed object"));
 862                        if (strict && fsck_walk(obj, NULL, &fsck_options))
 863                                die(_("Not all child objects of %s are reachable"), oid_to_hex(&obj->oid));
 864
 865                        if (obj->type == OBJ_TREE) {
 866                                struct tree *item = (struct tree *) obj;
 867                                item->buffer = NULL;
 868                                obj->parsed = 0;
 869                        }
 870                        if (obj->type == OBJ_COMMIT) {
 871                                struct commit *commit = (struct commit *) obj;
 872                                if (detach_commit_buffer(commit, NULL) != data)
 873                                        BUG("parse_object_buffer transmogrified our buffer");
 874                        }
 875                        obj->flags |= FLAG_CHECKED;
 876                }
 877                read_unlock();
 878        }
 879
 880        free(new_data);
 881}
 882
 883/*
 884 * This function is part of find_unresolved_deltas(). There are two
 885 * walkers going in the opposite ways.
 886 *
 887 * The first one in find_unresolved_deltas() traverses down from
 888 * parent node to children, deflating nodes along the way. However,
 889 * memory for deflated nodes is limited by delta_base_cache_limit, so
 890 * at some point parent node's deflated content may be freed.
 891 *
 892 * The second walker is this function, which goes from current node up
 893 * to top parent if necessary to deflate the node. In normal
 894 * situation, its parent node would be already deflated, so it just
 895 * needs to apply delta.
 896 *
 897 * In the worst case scenario, parent node is no longer deflated because
 898 * we're running out of delta_base_cache_limit; we need to re-deflate
 899 * parents, possibly up to the top base.
 900 *
 901 * All deflated objects here are subject to be freed if we exceed
 902 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 903 * just need to make sure the last node is not freed.
 904 */
 905static void *get_base_data(struct base_data *c)
 906{
 907        if (!c->data) {
 908                struct object_entry *obj = c->obj;
 909                struct base_data **delta = NULL;
 910                int delta_nr = 0, delta_alloc = 0;
 911
 912                while (is_delta_type(c->obj->type) && !c->data) {
 913                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 914                        delta[delta_nr++] = c;
 915                        c = c->base;
 916                }
 917                if (!delta_nr) {
 918                        c->data = get_data_from_pack(obj);
 919                        c->size = obj->size;
 920                        get_thread_data()->base_cache_used += c->size;
 921                        prune_base_data(c);
 922                }
 923                for (; delta_nr > 0; delta_nr--) {
 924                        void *base, *raw;
 925                        c = delta[delta_nr - 1];
 926                        obj = c->obj;
 927                        base = get_base_data(c->base);
 928                        raw = get_data_from_pack(obj);
 929                        c->data = patch_delta(
 930                                base, c->base->size,
 931                                raw, obj->size,
 932                                &c->size);
 933                        free(raw);
 934                        if (!c->data)
 935                                bad_object(obj->idx.offset, _("failed to apply delta"));
 936                        get_thread_data()->base_cache_used += c->size;
 937                        prune_base_data(c);
 938                }
 939                free(delta);
 940        }
 941        return c->data;
 942}
 943
 944static void resolve_delta(struct object_entry *delta_obj,
 945                          struct base_data *base, struct base_data *result)
 946{
 947        void *base_data, *delta_data;
 948
 949        if (show_stat) {
 950                int i = delta_obj - objects;
 951                int j = base->obj - objects;
 952                obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 953                deepest_delta_lock();
 954                if (deepest_delta < obj_stat[i].delta_depth)
 955                        deepest_delta = obj_stat[i].delta_depth;
 956                deepest_delta_unlock();
 957                obj_stat[i].base_object_no = j;
 958        }
 959        delta_data = get_data_from_pack(delta_obj);
 960        base_data = get_base_data(base);
 961        result->obj = delta_obj;
 962        result->data = patch_delta(base_data, base->size,
 963                                   delta_data, delta_obj->size, &result->size);
 964        free(delta_data);
 965        if (!result->data)
 966                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 967        hash_object_file(result->data, result->size,
 968                         type_name(delta_obj->real_type), &delta_obj->idx.oid);
 969        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 970                    &delta_obj->idx.oid);
 971        counter_lock();
 972        nr_resolved_deltas++;
 973        counter_unlock();
 974}
 975
 976/*
 977 * Standard boolean compare-and-swap: atomically check whether "*type" is
 978 * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 979 * and return false.
 980 */
 981static int compare_and_swap_type(signed char *type,
 982                                 enum object_type want,
 983                                 enum object_type set)
 984{
 985        enum object_type old;
 986
 987        type_cas_lock();
 988        old = *type;
 989        if (old == want)
 990                *type = set;
 991        type_cas_unlock();
 992
 993        return old == want;
 994}
 995
 996static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 997                                                  struct base_data *prev_base)
 998{
 999        if (base->ref_last == -1 && base->ofs_last == -1) {
1000                find_ref_delta_children(&base->obj->idx.oid,
1001                                        &base->ref_first, &base->ref_last,
1002                                        OBJ_REF_DELTA);
1003
1004                find_ofs_delta_children(base->obj->idx.offset,
1005                                        &base->ofs_first, &base->ofs_last,
1006                                        OBJ_OFS_DELTA);
1007
1008                if (base->ref_last == -1 && base->ofs_last == -1) {
1009                        free(base->data);
1010                        return NULL;
1011                }
1012
1013                link_base_data(prev_base, base);
1014        }
1015
1016        if (base->ref_first <= base->ref_last) {
1017                struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
1018                struct base_data *result = alloc_base_data();
1019
1020                if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
1021                                           base->obj->real_type))
1022                        BUG("child->real_type != OBJ_REF_DELTA");
1023
1024                resolve_delta(child, base, result);
1025                if (base->ref_first == base->ref_last && base->ofs_last == -1)
1026                        free_base_data(base);
1027
1028                base->ref_first++;
1029                return result;
1030        }
1031
1032        if (base->ofs_first <= base->ofs_last) {
1033                struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
1034                struct base_data *result = alloc_base_data();
1035
1036                assert(child->real_type == OBJ_OFS_DELTA);
1037                child->real_type = base->obj->real_type;
1038                resolve_delta(child, base, result);
1039                if (base->ofs_first == base->ofs_last)
1040                        free_base_data(base);
1041
1042                base->ofs_first++;
1043                return result;
1044        }
1045
1046        unlink_base_data(base);
1047        return NULL;
1048}
1049
1050static void find_unresolved_deltas(struct base_data *base)
1051{
1052        struct base_data *new_base, *prev_base = NULL;
1053        for (;;) {
1054                new_base = find_unresolved_deltas_1(base, prev_base);
1055
1056                if (new_base) {
1057                        prev_base = base;
1058                        base = new_base;
1059                } else {
1060                        free(base);
1061                        base = prev_base;
1062                        if (!base)
1063                                return;
1064                        prev_base = base->base;
1065                }
1066        }
1067}
1068
1069static int compare_ofs_delta_entry(const void *a, const void *b)
1070{
1071        const struct ofs_delta_entry *delta_a = a;
1072        const struct ofs_delta_entry *delta_b = b;
1073
1074        return delta_a->offset < delta_b->offset ? -1 :
1075               delta_a->offset > delta_b->offset ?  1 :
1076               0;
1077}
1078
1079static int compare_ref_delta_entry(const void *a, const void *b)
1080{
1081        const struct ref_delta_entry *delta_a = a;
1082        const struct ref_delta_entry *delta_b = b;
1083
1084        return oidcmp(&delta_a->oid, &delta_b->oid);
1085}
1086
1087static void resolve_base(struct object_entry *obj)
1088{
1089        struct base_data *base_obj = alloc_base_data();
1090        base_obj->obj = obj;
1091        base_obj->data = NULL;
1092        find_unresolved_deltas(base_obj);
1093}
1094
1095#ifndef NO_PTHREADS
1096static void *threaded_second_pass(void *data)
1097{
1098        set_thread_data(data);
1099        for (;;) {
1100                int i;
1101                counter_lock();
1102                display_progress(progress, nr_resolved_deltas);
1103                counter_unlock();
1104                work_lock();
1105                while (nr_dispatched < nr_objects &&
1106                       is_delta_type(objects[nr_dispatched].type))
1107                        nr_dispatched++;
1108                if (nr_dispatched >= nr_objects) {
1109                        work_unlock();
1110                        break;
1111                }
1112                i = nr_dispatched++;
1113                work_unlock();
1114
1115                resolve_base(&objects[i]);
1116        }
1117        return NULL;
1118}
1119#endif
1120
1121/*
1122 * First pass:
1123 * - find locations of all objects;
1124 * - calculate SHA1 of all non-delta objects;
1125 * - remember base (SHA1 or offset) for all deltas.
1126 */
1127static void parse_pack_objects(unsigned char *hash)
1128{
1129        int i, nr_delays = 0;
1130        struct ofs_delta_entry *ofs_delta = ofs_deltas;
1131        struct object_id ref_delta_oid;
1132        struct stat st;
1133
1134        if (verbose)
1135                progress = start_progress(
1136                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1137                                nr_objects);
1138        for (i = 0; i < nr_objects; i++) {
1139                struct object_entry *obj = &objects[i];
1140                void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1141                                              &ref_delta_oid,
1142                                              &obj->idx.oid);
1143                obj->real_type = obj->type;
1144                if (obj->type == OBJ_OFS_DELTA) {
1145                        nr_ofs_deltas++;
1146                        ofs_delta->obj_no = i;
1147                        ofs_delta++;
1148                } else if (obj->type == OBJ_REF_DELTA) {
1149                        ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1150                        oidcpy(&ref_deltas[nr_ref_deltas].oid, &ref_delta_oid);
1151                        ref_deltas[nr_ref_deltas].obj_no = i;
1152                        nr_ref_deltas++;
1153                } else if (!data) {
1154                        /* large blobs, check later */
1155                        obj->real_type = OBJ_BAD;
1156                        nr_delays++;
1157                } else
1158                        sha1_object(data, NULL, obj->size, obj->type,
1159                                    &obj->idx.oid);
1160                free(data);
1161                display_progress(progress, i+1);
1162        }
1163        objects[i].idx.offset = consumed_bytes;
1164        stop_progress(&progress);
1165
1166        /* Check pack integrity */
1167        flush();
1168        the_hash_algo->final_fn(hash, &input_ctx);
1169        if (hashcmp(fill(the_hash_algo->rawsz), hash))
1170                die(_("pack is corrupted (SHA1 mismatch)"));
1171        use(the_hash_algo->rawsz);
1172
1173        /* If input_fd is a file, we should have reached its end now. */
1174        if (fstat(input_fd, &st))
1175                die_errno(_("cannot fstat packfile"));
1176        if (S_ISREG(st.st_mode) &&
1177                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1178                die(_("pack has junk at the end"));
1179
1180        for (i = 0; i < nr_objects; i++) {
1181                struct object_entry *obj = &objects[i];
1182                if (obj->real_type != OBJ_BAD)
1183                        continue;
1184                obj->real_type = obj->type;
1185                sha1_object(NULL, obj, obj->size, obj->type,
1186                            &obj->idx.oid);
1187                nr_delays--;
1188        }
1189        if (nr_delays)
1190                die(_("confusion beyond insanity in parse_pack_objects()"));
1191}
1192
1193/*
1194 * Second pass:
1195 * - for all non-delta objects, look if it is used as a base for
1196 *   deltas;
1197 * - if used as a base, uncompress the object and apply all deltas,
1198 *   recursively checking if the resulting object is used as a base
1199 *   for some more deltas.
1200 */
1201static void resolve_deltas(void)
1202{
1203        int i;
1204
1205        if (!nr_ofs_deltas && !nr_ref_deltas)
1206                return;
1207
1208        /* Sort deltas by base SHA1/offset for fast searching */
1209        QSORT(ofs_deltas, nr_ofs_deltas, compare_ofs_delta_entry);
1210        QSORT(ref_deltas, nr_ref_deltas, compare_ref_delta_entry);
1211
1212        if (verbose || show_resolving_progress)
1213                progress = start_progress(_("Resolving deltas"),
1214                                          nr_ref_deltas + nr_ofs_deltas);
1215
1216#ifndef NO_PTHREADS
1217        nr_dispatched = 0;
1218        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1219                init_thread();
1220                for (i = 0; i < nr_threads; i++) {
1221                        int ret = pthread_create(&thread_data[i].thread, NULL,
1222                                                 threaded_second_pass, thread_data + i);
1223                        if (ret)
1224                                die(_("unable to create thread: %s"),
1225                                    strerror(ret));
1226                }
1227                for (i = 0; i < nr_threads; i++)
1228                        pthread_join(thread_data[i].thread, NULL);
1229                cleanup_thread();
1230                return;
1231        }
1232#endif
1233
1234        for (i = 0; i < nr_objects; i++) {
1235                struct object_entry *obj = &objects[i];
1236
1237                if (is_delta_type(obj->type))
1238                        continue;
1239                resolve_base(obj);
1240                display_progress(progress, nr_resolved_deltas);
1241        }
1242}
1243
1244/*
1245 * Third pass:
1246 * - append objects to convert thin pack to full pack if required
1247 * - write the final pack hash
1248 */
1249static void fix_unresolved_deltas(struct hashfile *f);
1250static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_hash)
1251{
1252        if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1253                stop_progress(&progress);
1254                /* Flush remaining pack final hash. */
1255                flush();
1256                return;
1257        }
1258
1259        if (fix_thin_pack) {
1260                struct hashfile *f;
1261                unsigned char read_hash[GIT_MAX_RAWSZ], tail_hash[GIT_MAX_RAWSZ];
1262                struct strbuf msg = STRBUF_INIT;
1263                int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1264                int nr_objects_initial = nr_objects;
1265                if (nr_unresolved <= 0)
1266                        die(_("confusion beyond insanity"));
1267                REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1268                memset(objects + nr_objects + 1, 0,
1269                       nr_unresolved * sizeof(*objects));
1270                f = hashfd(output_fd, curr_pack);
1271                fix_unresolved_deltas(f);
1272                strbuf_addf(&msg, Q_("completed with %d local object",
1273                                     "completed with %d local objects",
1274                                     nr_objects - nr_objects_initial),
1275                            nr_objects - nr_objects_initial);
1276                stop_progress_msg(&progress, msg.buf);
1277                strbuf_release(&msg);
1278                finalize_hashfile(f, tail_hash, 0);
1279                hashcpy(read_hash, pack_hash);
1280                fixup_pack_header_footer(output_fd, pack_hash,
1281                                         curr_pack, nr_objects,
1282                                         read_hash, consumed_bytes-the_hash_algo->rawsz);
1283                if (hashcmp(read_hash, tail_hash) != 0)
1284                        die(_("Unexpected tail checksum for %s "
1285                              "(disk corruption?)"), curr_pack);
1286        }
1287        if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1288                die(Q_("pack has %d unresolved delta",
1289                       "pack has %d unresolved deltas",
1290                       nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1291                    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1292}
1293
1294static int write_compressed(struct hashfile *f, void *in, unsigned int size)
1295{
1296        git_zstream stream;
1297        int status;
1298        unsigned char outbuf[4096];
1299
1300        git_deflate_init(&stream, zlib_compression_level);
1301        stream.next_in = in;
1302        stream.avail_in = size;
1303
1304        do {
1305                stream.next_out = outbuf;
1306                stream.avail_out = sizeof(outbuf);
1307                status = git_deflate(&stream, Z_FINISH);
1308                hashwrite(f, outbuf, sizeof(outbuf) - stream.avail_out);
1309        } while (status == Z_OK);
1310
1311        if (status != Z_STREAM_END)
1312                die(_("unable to deflate appended object (%d)"), status);
1313        size = stream.total_out;
1314        git_deflate_end(&stream);
1315        return size;
1316}
1317
1318static struct object_entry *append_obj_to_pack(struct hashfile *f,
1319                               const unsigned char *sha1, void *buf,
1320                               unsigned long size, enum object_type type)
1321{
1322        struct object_entry *obj = &objects[nr_objects++];
1323        unsigned char header[10];
1324        unsigned long s = size;
1325        int n = 0;
1326        unsigned char c = (type << 4) | (s & 15);
1327        s >>= 4;
1328        while (s) {
1329                header[n++] = c | 0x80;
1330                c = s & 0x7f;
1331                s >>= 7;
1332        }
1333        header[n++] = c;
1334        crc32_begin(f);
1335        hashwrite(f, header, n);
1336        obj[0].size = size;
1337        obj[0].hdr_size = n;
1338        obj[0].type = type;
1339        obj[0].real_type = type;
1340        obj[1].idx.offset = obj[0].idx.offset + n;
1341        obj[1].idx.offset += write_compressed(f, buf, size);
1342        obj[0].idx.crc32 = crc32_end(f);
1343        hashflush(f);
1344        hashcpy(obj->idx.oid.hash, sha1);
1345        return obj;
1346}
1347
1348static int delta_pos_compare(const void *_a, const void *_b)
1349{
1350        struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1351        struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1352        return a->obj_no - b->obj_no;
1353}
1354
1355static void fix_unresolved_deltas(struct hashfile *f)
1356{
1357        struct ref_delta_entry **sorted_by_pos;
1358        int i;
1359
1360        /*
1361         * Since many unresolved deltas may well be themselves base objects
1362         * for more unresolved deltas, we really want to include the
1363         * smallest number of base objects that would cover as much delta
1364         * as possible by picking the
1365         * trunc deltas first, allowing for other deltas to resolve without
1366         * additional base objects.  Since most base objects are to be found
1367         * before deltas depending on them, a good heuristic is to start
1368         * resolving deltas in the same order as their position in the pack.
1369         */
1370        ALLOC_ARRAY(sorted_by_pos, nr_ref_deltas);
1371        for (i = 0; i < nr_ref_deltas; i++)
1372                sorted_by_pos[i] = &ref_deltas[i];
1373        QSORT(sorted_by_pos, nr_ref_deltas, delta_pos_compare);
1374
1375        for (i = 0; i < nr_ref_deltas; i++) {
1376                struct ref_delta_entry *d = sorted_by_pos[i];
1377                enum object_type type;
1378                struct base_data *base_obj = alloc_base_data();
1379
1380                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1381                        continue;
1382                base_obj->data = read_object_file(&d->oid, &type,
1383                                                  &base_obj->size);
1384                if (!base_obj->data)
1385                        continue;
1386
1387                if (check_object_signature(&d->oid, base_obj->data,
1388                                base_obj->size, type_name(type)))
1389                        die(_("local object %s is corrupt"), oid_to_hex(&d->oid));
1390                base_obj->obj = append_obj_to_pack(f, d->oid.hash,
1391                                        base_obj->data, base_obj->size, type);
1392                find_unresolved_deltas(base_obj);
1393                display_progress(progress, nr_resolved_deltas);
1394        }
1395        free(sorted_by_pos);
1396}
1397
1398static const char *derive_filename(const char *pack_name, const char *suffix,
1399                                   struct strbuf *buf)
1400{
1401        size_t len;
1402        if (!strip_suffix(pack_name, ".pack", &len))
1403                die(_("packfile name '%s' does not end with '.pack'"),
1404                    pack_name);
1405        strbuf_add(buf, pack_name, len);
1406        strbuf_addch(buf, '.');
1407        strbuf_addstr(buf, suffix);
1408        return buf->buf;
1409}
1410
1411static void write_special_file(const char *suffix, const char *msg,
1412                               const char *pack_name, const unsigned char *hash,
1413                               const char **report)
1414{
1415        struct strbuf name_buf = STRBUF_INIT;
1416        const char *filename;
1417        int fd;
1418        int msg_len = strlen(msg);
1419
1420        if (pack_name)
1421                filename = derive_filename(pack_name, suffix, &name_buf);
1422        else
1423                filename = odb_pack_name(&name_buf, hash, suffix);
1424
1425        fd = odb_pack_keep(filename);
1426        if (fd < 0) {
1427                if (errno != EEXIST)
1428                        die_errno(_("cannot write %s file '%s'"),
1429                                  suffix, filename);
1430        } else {
1431                if (msg_len > 0) {
1432                        write_or_die(fd, msg, msg_len);
1433                        write_or_die(fd, "\n", 1);
1434                }
1435                if (close(fd) != 0)
1436                        die_errno(_("cannot close written %s file '%s'"),
1437                                  suffix, filename);
1438                if (report)
1439                        *report = suffix;
1440        }
1441        strbuf_release(&name_buf);
1442}
1443
1444static void final(const char *final_pack_name, const char *curr_pack_name,
1445                  const char *final_index_name, const char *curr_index_name,
1446                  const char *keep_msg, const char *promisor_msg,
1447                  unsigned char *hash)
1448{
1449        const char *report = "pack";
1450        struct strbuf pack_name = STRBUF_INIT;
1451        struct strbuf index_name = STRBUF_INIT;
1452        int err;
1453
1454        if (!from_stdin) {
1455                close(input_fd);
1456        } else {
1457                fsync_or_die(output_fd, curr_pack_name);
1458                err = close(output_fd);
1459                if (err)
1460                        die_errno(_("error while closing pack file"));
1461        }
1462
1463        if (keep_msg)
1464                write_special_file("keep", keep_msg, final_pack_name, hash,
1465                                   &report);
1466        if (promisor_msg)
1467                write_special_file("promisor", promisor_msg, final_pack_name,
1468                                   hash, NULL);
1469
1470        if (final_pack_name != curr_pack_name) {
1471                if (!final_pack_name)
1472                        final_pack_name = odb_pack_name(&pack_name, hash, "pack");
1473                if (finalize_object_file(curr_pack_name, final_pack_name))
1474                        die(_("cannot store pack file"));
1475        } else if (from_stdin)
1476                chmod(final_pack_name, 0444);
1477
1478        if (final_index_name != curr_index_name) {
1479                if (!final_index_name)
1480                        final_index_name = odb_pack_name(&index_name, hash, "idx");
1481                if (finalize_object_file(curr_index_name, final_index_name))
1482                        die(_("cannot store index file"));
1483        } else
1484                chmod(final_index_name, 0444);
1485
1486        if (do_fsck_object) {
1487                struct packed_git *p;
1488                p = add_packed_git(final_index_name, strlen(final_index_name), 0);
1489                if (p)
1490                        install_packed_git(the_repository, p);
1491        }
1492
1493        if (!from_stdin) {
1494                printf("%s\n", sha1_to_hex(hash));
1495        } else {
1496                struct strbuf buf = STRBUF_INIT;
1497
1498                strbuf_addf(&buf, "%s\t%s\n", report, sha1_to_hex(hash));
1499                write_or_die(1, buf.buf, buf.len);
1500                strbuf_release(&buf);
1501
1502                /*
1503                 * Let's just mimic git-unpack-objects here and write
1504                 * the last part of the input buffer to stdout.
1505                 */
1506                while (input_len) {
1507                        err = xwrite(1, input_buffer + input_offset, input_len);
1508                        if (err <= 0)
1509                                break;
1510                        input_len -= err;
1511                        input_offset += err;
1512                }
1513        }
1514
1515        strbuf_release(&index_name);
1516        strbuf_release(&pack_name);
1517}
1518
1519static int git_index_pack_config(const char *k, const char *v, void *cb)
1520{
1521        struct pack_idx_option *opts = cb;
1522
1523        if (!strcmp(k, "pack.indexversion")) {
1524                opts->version = git_config_int(k, v);
1525                if (opts->version > 2)
1526                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1527                return 0;
1528        }
1529        if (!strcmp(k, "pack.threads")) {
1530                nr_threads = git_config_int(k, v);
1531                if (nr_threads < 0)
1532                        die(_("invalid number of threads specified (%d)"),
1533                            nr_threads);
1534#ifdef NO_PTHREADS
1535                if (nr_threads != 1)
1536                        warning(_("no threads support, ignoring %s"), k);
1537                nr_threads = 1;
1538#endif
1539                return 0;
1540        }
1541        return git_default_config(k, v, cb);
1542}
1543
1544static int cmp_uint32(const void *a_, const void *b_)
1545{
1546        uint32_t a = *((uint32_t *)a_);
1547        uint32_t b = *((uint32_t *)b_);
1548
1549        return (a < b) ? -1 : (a != b);
1550}
1551
1552static void read_v2_anomalous_offsets(struct packed_git *p,
1553                                      struct pack_idx_option *opts)
1554{
1555        const uint32_t *idx1, *idx2;
1556        uint32_t i;
1557        const uint32_t hashwords = the_hash_algo->rawsz / sizeof(uint32_t);
1558
1559        /* The address of the 4-byte offset table */
1560        idx1 = (((const uint32_t *)p->index_data)
1561                + 2 /* 8-byte header */
1562                + 256 /* fan out */
1563                + hashwords * p->num_objects /* object ID table */
1564                + p->num_objects /* CRC32 table */
1565                );
1566
1567        /* The address of the 8-byte offset table */
1568        idx2 = idx1 + p->num_objects;
1569
1570        for (i = 0; i < p->num_objects; i++) {
1571                uint32_t off = ntohl(idx1[i]);
1572                if (!(off & 0x80000000))
1573                        continue;
1574                off = off & 0x7fffffff;
1575                check_pack_index_ptr(p, &idx2[off * 2]);
1576                if (idx2[off * 2])
1577                        continue;
1578                /*
1579                 * The real offset is ntohl(idx2[off * 2]) in high 4
1580                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1581                 * octets.  But idx2[off * 2] is Zero!!!
1582                 */
1583                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1584                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1585        }
1586
1587        QSORT(opts->anomaly, opts->anomaly_nr, cmp_uint32);
1588}
1589
1590static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1591{
1592        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1593
1594        if (!p)
1595                die(_("Cannot open existing pack file '%s'"), pack_name);
1596        if (open_pack_index(p))
1597                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1598
1599        /* Read the attributes from the existing idx file */
1600        opts->version = p->index_version;
1601
1602        if (opts->version == 2)
1603                read_v2_anomalous_offsets(p, opts);
1604
1605        /*
1606         * Get rid of the idx file as we do not need it anymore.
1607         * NEEDSWORK: extract this bit from free_pack_by_name() in
1608         * sha1-file.c, perhaps?  It shouldn't matter very much as we
1609         * know we haven't installed this pack (hence we never have
1610         * read anything from it).
1611         */
1612        close_pack_index(p);
1613        free(p);
1614}
1615
1616static void show_pack_info(int stat_only)
1617{
1618        int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1619        unsigned long *chain_histogram = NULL;
1620
1621        if (deepest_delta)
1622                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1623
1624        for (i = 0; i < nr_objects; i++) {
1625                struct object_entry *obj = &objects[i];
1626
1627                if (is_delta_type(obj->type))
1628                        chain_histogram[obj_stat[i].delta_depth - 1]++;
1629                if (stat_only)
1630                        continue;
1631                printf("%s %-6s %lu %lu %"PRIuMAX,
1632                       oid_to_hex(&obj->idx.oid),
1633                       type_name(obj->real_type), obj->size,
1634                       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1635                       (uintmax_t)obj->idx.offset);
1636                if (is_delta_type(obj->type)) {
1637                        struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1638                        printf(" %u %s", obj_stat[i].delta_depth,
1639                               oid_to_hex(&bobj->idx.oid));
1640                }
1641                putchar('\n');
1642        }
1643
1644        if (baseobjects)
1645                printf_ln(Q_("non delta: %d object",
1646                             "non delta: %d objects",
1647                             baseobjects),
1648                          baseobjects);
1649        for (i = 0; i < deepest_delta; i++) {
1650                if (!chain_histogram[i])
1651                        continue;
1652                printf_ln(Q_("chain length = %d: %lu object",
1653                             "chain length = %d: %lu objects",
1654                             chain_histogram[i]),
1655                          i + 1,
1656                          chain_histogram[i]);
1657        }
1658}
1659
1660int cmd_index_pack(int argc, const char **argv, const char *prefix)
1661{
1662        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1663        const char *curr_index;
1664        const char *index_name = NULL, *pack_name = NULL;
1665        const char *keep_msg = NULL;
1666        const char *promisor_msg = NULL;
1667        struct strbuf index_name_buf = STRBUF_INIT;
1668        struct pack_idx_entry **idx_objects;
1669        struct pack_idx_option opts;
1670        unsigned char pack_hash[GIT_MAX_RAWSZ];
1671        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1672        int report_end_of_input = 0;
1673
1674        /*
1675         * index-pack never needs to fetch missing objects, since it only
1676         * accesses the repo to do hash collision checks
1677         */
1678        fetch_if_missing = 0;
1679
1680        if (argc == 2 && !strcmp(argv[1], "-h"))
1681                usage(index_pack_usage);
1682
1683        check_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#ifdef NO_PTHREADS
1727                                if (nr_threads != 1)
1728                                        warning(_("no threads support, "
1729                                                  "ignoring %s"), arg);
1730                                nr_threads = 1;
1731#endif
1732                        } else if (starts_with(arg, "--pack_header=")) {
1733                                struct pack_header *hdr;
1734                                char *c;
1735
1736                                hdr = (struct pack_header *)input_buffer;
1737                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1738                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1739                                if (*c != ',')
1740                                        die(_("bad %s"), arg);
1741                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1742                                if (*c)
1743                                        die(_("bad %s"), arg);
1744                                input_len = sizeof(*hdr);
1745                        } else if (!strcmp(arg, "-v")) {
1746                                verbose = 1;
1747                        } else if (!strcmp(arg, "--show-resolving-progress")) {
1748                                show_resolving_progress = 1;
1749                        } else if (!strcmp(arg, "--report-end-of-input")) {
1750                                report_end_of_input = 1;
1751                        } else if (!strcmp(arg, "-o")) {
1752                                if (index_name || (i+1) >= argc)
1753                                        usage(index_pack_usage);
1754                                index_name = argv[++i];
1755                        } else if (starts_with(arg, "--index-version=")) {
1756                                char *c;
1757                                opts.version = strtoul(arg + 16, &c, 10);
1758                                if (opts.version > 2)
1759                                        die(_("bad %s"), arg);
1760                                if (*c == ',')
1761                                        opts.off32_limit = strtoul(c+1, &c, 0);
1762                                if (*c || opts.off32_limit & 0x80000000)
1763                                        die(_("bad %s"), arg);
1764                        } else if (skip_prefix(arg, "--max-input-size=", &arg)) {
1765                                max_input_size = strtoumax(arg, NULL, 10);
1766                        } else
1767                                usage(index_pack_usage);
1768                        continue;
1769                }
1770
1771                if (pack_name)
1772                        usage(index_pack_usage);
1773                pack_name = arg;
1774        }
1775
1776        if (!pack_name && !from_stdin)
1777                usage(index_pack_usage);
1778        if (fix_thin_pack && !from_stdin)
1779                die(_("--fix-thin cannot be used without --stdin"));
1780        if (from_stdin && !startup_info->have_repository)
1781                die(_("--stdin requires a git repository"));
1782        if (!index_name && pack_name)
1783                index_name = derive_filename(pack_name, "idx", &index_name_buf);
1784
1785        if (verify) {
1786                if (!index_name)
1787                        die(_("--verify with no packfile name given"));
1788                read_idx_option(&opts, index_name);
1789                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1790        }
1791        if (strict)
1792                opts.flags |= WRITE_IDX_STRICT;
1793
1794#ifndef NO_PTHREADS
1795        if (!nr_threads) {
1796                nr_threads = online_cpus();
1797                /* An experiment showed that more threads does not mean faster */
1798                if (nr_threads > 3)
1799                        nr_threads = 3;
1800        }
1801#endif
1802
1803        curr_pack = open_pack_file(pack_name);
1804        parse_pack_header();
1805        objects = xcalloc(st_add(nr_objects, 1), sizeof(struct object_entry));
1806        if (show_stat)
1807                obj_stat = xcalloc(st_add(nr_objects, 1), sizeof(struct object_stat));
1808        ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
1809        parse_pack_objects(pack_hash);
1810        if (report_end_of_input)
1811                write_in_full(2, "\0", 1);
1812        resolve_deltas();
1813        conclude_pack(fix_thin_pack, curr_pack, pack_hash);
1814        free(ofs_deltas);
1815        free(ref_deltas);
1816        if (strict)
1817                foreign_nr = check_objects();
1818
1819        if (show_stat)
1820                show_pack_info(stat_only);
1821
1822        ALLOC_ARRAY(idx_objects, nr_objects);
1823        for (i = 0; i < nr_objects; i++)
1824                idx_objects[i] = &objects[i].idx;
1825        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_hash);
1826        free(idx_objects);
1827
1828        if (!verify)
1829                final(pack_name, curr_pack,
1830                      index_name, curr_index,
1831                      keep_msg, promisor_msg,
1832                      pack_hash);
1833        else
1834                close(input_fd);
1835
1836        if (do_fsck_object && fsck_finish(&fsck_options))
1837                die(_("fsck error in pack objects"));
1838
1839        free(objects);
1840        strbuf_release(&index_name_buf);
1841        if (pack_name == NULL)
1842                free((void *) curr_pack);
1843        if (index_name == NULL)
1844                free((void *) curr_index);
1845
1846        /*
1847         * Let the caller know this pack is not self contained
1848         */
1849        if (check_self_contained_and_connected && foreign_nr)
1850                return 1;
1851
1852        return 0;
1853}