builtin / index-pack.con commit gc --auto: exclude base pack if not enough mem to "repack -ad" (9806f5a)
   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(&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(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(oid);
 836                        if (blob)
 837                                blob->object.flags |= FLAG_CHECKED;
 838                        else
 839                                die(_("invalid blob object %s"), oid_to_hex(oid));
 840                } else {
 841                        struct object *obj;
 842                        int eaten;
 843                        void *buf = (void *) data;
 844
 845                        assert(data && "data can only be NULL for large _blobs_");
 846
 847                        /*
 848                         * we do not need to free the memory here, as the
 849                         * buf is deleted by the caller.
 850                         */
 851                        obj = parse_object_buffer(oid, type, size, buf,
 852                                                  &eaten);
 853                        if (!obj)
 854                                die(_("invalid %s"), type_name(type));
 855                        if (do_fsck_object &&
 856                            fsck_object(obj, buf, size, &fsck_options))
 857                                die(_("Error in object"));
 858                        if (strict && fsck_walk(obj, NULL, &fsck_options))
 859                                die(_("Not all child objects of %s are reachable"), oid_to_hex(&obj->oid));
 860
 861                        if (obj->type == OBJ_TREE) {
 862                                struct tree *item = (struct tree *) obj;
 863                                item->buffer = NULL;
 864                                obj->parsed = 0;
 865                        }
 866                        if (obj->type == OBJ_COMMIT) {
 867                                struct commit *commit = (struct commit *) obj;
 868                                if (detach_commit_buffer(commit, NULL) != data)
 869                                        die("BUG: parse_object_buffer transmogrified our buffer");
 870                        }
 871                        obj->flags |= FLAG_CHECKED;
 872                }
 873                read_unlock();
 874        }
 875
 876        free(new_data);
 877}
 878
 879/*
 880 * This function is part of find_unresolved_deltas(). There are two
 881 * walkers going in the opposite ways.
 882 *
 883 * The first one in find_unresolved_deltas() traverses down from
 884 * parent node to children, deflating nodes along the way. However,
 885 * memory for deflated nodes is limited by delta_base_cache_limit, so
 886 * at some point parent node's deflated content may be freed.
 887 *
 888 * The second walker is this function, which goes from current node up
 889 * to top parent if necessary to deflate the node. In normal
 890 * situation, its parent node would be already deflated, so it just
 891 * needs to apply delta.
 892 *
 893 * In the worst case scenario, parent node is no longer deflated because
 894 * we're running out of delta_base_cache_limit; we need to re-deflate
 895 * parents, possibly up to the top base.
 896 *
 897 * All deflated objects here are subject to be freed if we exceed
 898 * delta_base_cache_limit, just like in find_unresolved_deltas(), we
 899 * just need to make sure the last node is not freed.
 900 */
 901static void *get_base_data(struct base_data *c)
 902{
 903        if (!c->data) {
 904                struct object_entry *obj = c->obj;
 905                struct base_data **delta = NULL;
 906                int delta_nr = 0, delta_alloc = 0;
 907
 908                while (is_delta_type(c->obj->type) && !c->data) {
 909                        ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
 910                        delta[delta_nr++] = c;
 911                        c = c->base;
 912                }
 913                if (!delta_nr) {
 914                        c->data = get_data_from_pack(obj);
 915                        c->size = obj->size;
 916                        get_thread_data()->base_cache_used += c->size;
 917                        prune_base_data(c);
 918                }
 919                for (; delta_nr > 0; delta_nr--) {
 920                        void *base, *raw;
 921                        c = delta[delta_nr - 1];
 922                        obj = c->obj;
 923                        base = get_base_data(c->base);
 924                        raw = get_data_from_pack(obj);
 925                        c->data = patch_delta(
 926                                base, c->base->size,
 927                                raw, obj->size,
 928                                &c->size);
 929                        free(raw);
 930                        if (!c->data)
 931                                bad_object(obj->idx.offset, _("failed to apply delta"));
 932                        get_thread_data()->base_cache_used += c->size;
 933                        prune_base_data(c);
 934                }
 935                free(delta);
 936        }
 937        return c->data;
 938}
 939
 940static void resolve_delta(struct object_entry *delta_obj,
 941                          struct base_data *base, struct base_data *result)
 942{
 943        void *base_data, *delta_data;
 944
 945        if (show_stat) {
 946                int i = delta_obj - objects;
 947                int j = base->obj - objects;
 948                obj_stat[i].delta_depth = obj_stat[j].delta_depth + 1;
 949                deepest_delta_lock();
 950                if (deepest_delta < obj_stat[i].delta_depth)
 951                        deepest_delta = obj_stat[i].delta_depth;
 952                deepest_delta_unlock();
 953                obj_stat[i].base_object_no = j;
 954        }
 955        delta_data = get_data_from_pack(delta_obj);
 956        base_data = get_base_data(base);
 957        result->obj = delta_obj;
 958        result->data = patch_delta(base_data, base->size,
 959                                   delta_data, delta_obj->size, &result->size);
 960        free(delta_data);
 961        if (!result->data)
 962                bad_object(delta_obj->idx.offset, _("failed to apply delta"));
 963        hash_object_file(result->data, result->size,
 964                         type_name(delta_obj->real_type), &delta_obj->idx.oid);
 965        sha1_object(result->data, NULL, result->size, delta_obj->real_type,
 966                    &delta_obj->idx.oid);
 967        counter_lock();
 968        nr_resolved_deltas++;
 969        counter_unlock();
 970}
 971
 972/*
 973 * Standard boolean compare-and-swap: atomically check whether "*type" is
 974 * "want"; if so, swap in "set" and return true. Otherwise, leave it untouched
 975 * and return false.
 976 */
 977static int compare_and_swap_type(signed char *type,
 978                                 enum object_type want,
 979                                 enum object_type set)
 980{
 981        enum object_type old;
 982
 983        type_cas_lock();
 984        old = *type;
 985        if (old == want)
 986                *type = set;
 987        type_cas_unlock();
 988
 989        return old == want;
 990}
 991
 992static struct base_data *find_unresolved_deltas_1(struct base_data *base,
 993                                                  struct base_data *prev_base)
 994{
 995        if (base->ref_last == -1 && base->ofs_last == -1) {
 996                find_ref_delta_children(&base->obj->idx.oid,
 997                                        &base->ref_first, &base->ref_last,
 998                                        OBJ_REF_DELTA);
 999
1000                find_ofs_delta_children(base->obj->idx.offset,
1001                                        &base->ofs_first, &base->ofs_last,
1002                                        OBJ_OFS_DELTA);
1003
1004                if (base->ref_last == -1 && base->ofs_last == -1) {
1005                        free(base->data);
1006                        return NULL;
1007                }
1008
1009                link_base_data(prev_base, base);
1010        }
1011
1012        if (base->ref_first <= base->ref_last) {
1013                struct object_entry *child = objects + ref_deltas[base->ref_first].obj_no;
1014                struct base_data *result = alloc_base_data();
1015
1016                if (!compare_and_swap_type(&child->real_type, OBJ_REF_DELTA,
1017                                           base->obj->real_type))
1018                        die("BUG: child->real_type != OBJ_REF_DELTA");
1019
1020                resolve_delta(child, base, result);
1021                if (base->ref_first == base->ref_last && base->ofs_last == -1)
1022                        free_base_data(base);
1023
1024                base->ref_first++;
1025                return result;
1026        }
1027
1028        if (base->ofs_first <= base->ofs_last) {
1029                struct object_entry *child = objects + ofs_deltas[base->ofs_first].obj_no;
1030                struct base_data *result = alloc_base_data();
1031
1032                assert(child->real_type == OBJ_OFS_DELTA);
1033                child->real_type = base->obj->real_type;
1034                resolve_delta(child, base, result);
1035                if (base->ofs_first == base->ofs_last)
1036                        free_base_data(base);
1037
1038                base->ofs_first++;
1039                return result;
1040        }
1041
1042        unlink_base_data(base);
1043        return NULL;
1044}
1045
1046static void find_unresolved_deltas(struct base_data *base)
1047{
1048        struct base_data *new_base, *prev_base = NULL;
1049        for (;;) {
1050                new_base = find_unresolved_deltas_1(base, prev_base);
1051
1052                if (new_base) {
1053                        prev_base = base;
1054                        base = new_base;
1055                } else {
1056                        free(base);
1057                        base = prev_base;
1058                        if (!base)
1059                                return;
1060                        prev_base = base->base;
1061                }
1062        }
1063}
1064
1065static int compare_ofs_delta_entry(const void *a, const void *b)
1066{
1067        const struct ofs_delta_entry *delta_a = a;
1068        const struct ofs_delta_entry *delta_b = b;
1069
1070        return delta_a->offset < delta_b->offset ? -1 :
1071               delta_a->offset > delta_b->offset ?  1 :
1072               0;
1073}
1074
1075static int compare_ref_delta_entry(const void *a, const void *b)
1076{
1077        const struct ref_delta_entry *delta_a = a;
1078        const struct ref_delta_entry *delta_b = b;
1079
1080        return oidcmp(&delta_a->oid, &delta_b->oid);
1081}
1082
1083static void resolve_base(struct object_entry *obj)
1084{
1085        struct base_data *base_obj = alloc_base_data();
1086        base_obj->obj = obj;
1087        base_obj->data = NULL;
1088        find_unresolved_deltas(base_obj);
1089}
1090
1091#ifndef NO_PTHREADS
1092static void *threaded_second_pass(void *data)
1093{
1094        set_thread_data(data);
1095        for (;;) {
1096                int i;
1097                counter_lock();
1098                display_progress(progress, nr_resolved_deltas);
1099                counter_unlock();
1100                work_lock();
1101                while (nr_dispatched < nr_objects &&
1102                       is_delta_type(objects[nr_dispatched].type))
1103                        nr_dispatched++;
1104                if (nr_dispatched >= nr_objects) {
1105                        work_unlock();
1106                        break;
1107                }
1108                i = nr_dispatched++;
1109                work_unlock();
1110
1111                resolve_base(&objects[i]);
1112        }
1113        return NULL;
1114}
1115#endif
1116
1117/*
1118 * First pass:
1119 * - find locations of all objects;
1120 * - calculate SHA1 of all non-delta objects;
1121 * - remember base (SHA1 or offset) for all deltas.
1122 */
1123static void parse_pack_objects(unsigned char *hash)
1124{
1125        int i, nr_delays = 0;
1126        struct ofs_delta_entry *ofs_delta = ofs_deltas;
1127        struct object_id ref_delta_oid;
1128        struct stat st;
1129
1130        if (verbose)
1131                progress = start_progress(
1132                                from_stdin ? _("Receiving objects") : _("Indexing objects"),
1133                                nr_objects);
1134        for (i = 0; i < nr_objects; i++) {
1135                struct object_entry *obj = &objects[i];
1136                void *data = unpack_raw_entry(obj, &ofs_delta->offset,
1137                                              &ref_delta_oid,
1138                                              &obj->idx.oid);
1139                obj->real_type = obj->type;
1140                if (obj->type == OBJ_OFS_DELTA) {
1141                        nr_ofs_deltas++;
1142                        ofs_delta->obj_no = i;
1143                        ofs_delta++;
1144                } else if (obj->type == OBJ_REF_DELTA) {
1145                        ALLOC_GROW(ref_deltas, nr_ref_deltas + 1, ref_deltas_alloc);
1146                        oidcpy(&ref_deltas[nr_ref_deltas].oid, &ref_delta_oid);
1147                        ref_deltas[nr_ref_deltas].obj_no = i;
1148                        nr_ref_deltas++;
1149                } else if (!data) {
1150                        /* large blobs, check later */
1151                        obj->real_type = OBJ_BAD;
1152                        nr_delays++;
1153                } else
1154                        sha1_object(data, NULL, obj->size, obj->type,
1155                                    &obj->idx.oid);
1156                free(data);
1157                display_progress(progress, i+1);
1158        }
1159        objects[i].idx.offset = consumed_bytes;
1160        stop_progress(&progress);
1161
1162        /* Check pack integrity */
1163        flush();
1164        the_hash_algo->final_fn(hash, &input_ctx);
1165        if (hashcmp(fill(the_hash_algo->rawsz), hash))
1166                die(_("pack is corrupted (SHA1 mismatch)"));
1167        use(the_hash_algo->rawsz);
1168
1169        /* If input_fd is a file, we should have reached its end now. */
1170        if (fstat(input_fd, &st))
1171                die_errno(_("cannot fstat packfile"));
1172        if (S_ISREG(st.st_mode) &&
1173                        lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
1174                die(_("pack has junk at the end"));
1175
1176        for (i = 0; i < nr_objects; i++) {
1177                struct object_entry *obj = &objects[i];
1178                if (obj->real_type != OBJ_BAD)
1179                        continue;
1180                obj->real_type = obj->type;
1181                sha1_object(NULL, obj, obj->size, obj->type,
1182                            &obj->idx.oid);
1183                nr_delays--;
1184        }
1185        if (nr_delays)
1186                die(_("confusion beyond insanity in parse_pack_objects()"));
1187}
1188
1189/*
1190 * Second pass:
1191 * - for all non-delta objects, look if it is used as a base for
1192 *   deltas;
1193 * - if used as a base, uncompress the object and apply all deltas,
1194 *   recursively checking if the resulting object is used as a base
1195 *   for some more deltas.
1196 */
1197static void resolve_deltas(void)
1198{
1199        int i;
1200
1201        if (!nr_ofs_deltas && !nr_ref_deltas)
1202                return;
1203
1204        /* Sort deltas by base SHA1/offset for fast searching */
1205        QSORT(ofs_deltas, nr_ofs_deltas, compare_ofs_delta_entry);
1206        QSORT(ref_deltas, nr_ref_deltas, compare_ref_delta_entry);
1207
1208        if (verbose || show_resolving_progress)
1209                progress = start_progress(_("Resolving deltas"),
1210                                          nr_ref_deltas + nr_ofs_deltas);
1211
1212#ifndef NO_PTHREADS
1213        nr_dispatched = 0;
1214        if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
1215                init_thread();
1216                for (i = 0; i < nr_threads; i++) {
1217                        int ret = pthread_create(&thread_data[i].thread, NULL,
1218                                                 threaded_second_pass, thread_data + i);
1219                        if (ret)
1220                                die(_("unable to create thread: %s"),
1221                                    strerror(ret));
1222                }
1223                for (i = 0; i < nr_threads; i++)
1224                        pthread_join(thread_data[i].thread, NULL);
1225                cleanup_thread();
1226                return;
1227        }
1228#endif
1229
1230        for (i = 0; i < nr_objects; i++) {
1231                struct object_entry *obj = &objects[i];
1232
1233                if (is_delta_type(obj->type))
1234                        continue;
1235                resolve_base(obj);
1236                display_progress(progress, nr_resolved_deltas);
1237        }
1238}
1239
1240/*
1241 * Third pass:
1242 * - append objects to convert thin pack to full pack if required
1243 * - write the final pack hash
1244 */
1245static void fix_unresolved_deltas(struct hashfile *f);
1246static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_hash)
1247{
1248        if (nr_ref_deltas + nr_ofs_deltas == nr_resolved_deltas) {
1249                stop_progress(&progress);
1250                /* Flush remaining pack final hash. */
1251                flush();
1252                return;
1253        }
1254
1255        if (fix_thin_pack) {
1256                struct hashfile *f;
1257                unsigned char read_hash[GIT_MAX_RAWSZ], tail_hash[GIT_MAX_RAWSZ];
1258                struct strbuf msg = STRBUF_INIT;
1259                int nr_unresolved = nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas;
1260                int nr_objects_initial = nr_objects;
1261                if (nr_unresolved <= 0)
1262                        die(_("confusion beyond insanity"));
1263                REALLOC_ARRAY(objects, nr_objects + nr_unresolved + 1);
1264                memset(objects + nr_objects + 1, 0,
1265                       nr_unresolved * sizeof(*objects));
1266                f = hashfd(output_fd, curr_pack);
1267                fix_unresolved_deltas(f);
1268                strbuf_addf(&msg, Q_("completed with %d local object",
1269                                     "completed with %d local objects",
1270                                     nr_objects - nr_objects_initial),
1271                            nr_objects - nr_objects_initial);
1272                stop_progress_msg(&progress, msg.buf);
1273                strbuf_release(&msg);
1274                hashclose(f, tail_hash, 0);
1275                hashcpy(read_hash, pack_hash);
1276                fixup_pack_header_footer(output_fd, pack_hash,
1277                                         curr_pack, nr_objects,
1278                                         read_hash, consumed_bytes-the_hash_algo->rawsz);
1279                if (hashcmp(read_hash, tail_hash) != 0)
1280                        die(_("Unexpected tail checksum for %s "
1281                              "(disk corruption?)"), curr_pack);
1282        }
1283        if (nr_ofs_deltas + nr_ref_deltas != nr_resolved_deltas)
1284                die(Q_("pack has %d unresolved delta",
1285                       "pack has %d unresolved deltas",
1286                       nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas),
1287                    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
1288}
1289
1290static int write_compressed(struct hashfile *f, void *in, unsigned int size)
1291{
1292        git_zstream stream;
1293        int status;
1294        unsigned char outbuf[4096];
1295
1296        git_deflate_init(&stream, zlib_compression_level);
1297        stream.next_in = in;
1298        stream.avail_in = size;
1299
1300        do {
1301                stream.next_out = outbuf;
1302                stream.avail_out = sizeof(outbuf);
1303                status = git_deflate(&stream, Z_FINISH);
1304                hashwrite(f, outbuf, sizeof(outbuf) - stream.avail_out);
1305        } while (status == Z_OK);
1306
1307        if (status != Z_STREAM_END)
1308                die(_("unable to deflate appended object (%d)"), status);
1309        size = stream.total_out;
1310        git_deflate_end(&stream);
1311        return size;
1312}
1313
1314static struct object_entry *append_obj_to_pack(struct hashfile *f,
1315                               const unsigned char *sha1, void *buf,
1316                               unsigned long size, enum object_type type)
1317{
1318        struct object_entry *obj = &objects[nr_objects++];
1319        unsigned char header[10];
1320        unsigned long s = size;
1321        int n = 0;
1322        unsigned char c = (type << 4) | (s & 15);
1323        s >>= 4;
1324        while (s) {
1325                header[n++] = c | 0x80;
1326                c = s & 0x7f;
1327                s >>= 7;
1328        }
1329        header[n++] = c;
1330        crc32_begin(f);
1331        hashwrite(f, header, n);
1332        obj[0].size = size;
1333        obj[0].hdr_size = n;
1334        obj[0].type = type;
1335        obj[0].real_type = type;
1336        obj[1].idx.offset = obj[0].idx.offset + n;
1337        obj[1].idx.offset += write_compressed(f, buf, size);
1338        obj[0].idx.crc32 = crc32_end(f);
1339        hashflush(f);
1340        hashcpy(obj->idx.oid.hash, sha1);
1341        return obj;
1342}
1343
1344static int delta_pos_compare(const void *_a, const void *_b)
1345{
1346        struct ref_delta_entry *a = *(struct ref_delta_entry **)_a;
1347        struct ref_delta_entry *b = *(struct ref_delta_entry **)_b;
1348        return a->obj_no - b->obj_no;
1349}
1350
1351static void fix_unresolved_deltas(struct hashfile *f)
1352{
1353        struct ref_delta_entry **sorted_by_pos;
1354        int i;
1355
1356        /*
1357         * Since many unresolved deltas may well be themselves base objects
1358         * for more unresolved deltas, we really want to include the
1359         * smallest number of base objects that would cover as much delta
1360         * as possible by picking the
1361         * trunc deltas first, allowing for other deltas to resolve without
1362         * additional base objects.  Since most base objects are to be found
1363         * before deltas depending on them, a good heuristic is to start
1364         * resolving deltas in the same order as their position in the pack.
1365         */
1366        ALLOC_ARRAY(sorted_by_pos, nr_ref_deltas);
1367        for (i = 0; i < nr_ref_deltas; i++)
1368                sorted_by_pos[i] = &ref_deltas[i];
1369        QSORT(sorted_by_pos, nr_ref_deltas, delta_pos_compare);
1370
1371        for (i = 0; i < nr_ref_deltas; i++) {
1372                struct ref_delta_entry *d = sorted_by_pos[i];
1373                enum object_type type;
1374                struct base_data *base_obj = alloc_base_data();
1375
1376                if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
1377                        continue;
1378                base_obj->data = read_object_file(&d->oid, &type,
1379                                                  &base_obj->size);
1380                if (!base_obj->data)
1381                        continue;
1382
1383                if (check_object_signature(&d->oid, base_obj->data,
1384                                base_obj->size, type_name(type)))
1385                        die(_("local object %s is corrupt"), oid_to_hex(&d->oid));
1386                base_obj->obj = append_obj_to_pack(f, d->oid.hash,
1387                                        base_obj->data, base_obj->size, type);
1388                find_unresolved_deltas(base_obj);
1389                display_progress(progress, nr_resolved_deltas);
1390        }
1391        free(sorted_by_pos);
1392}
1393
1394static const char *derive_filename(const char *pack_name, const char *suffix,
1395                                   struct strbuf *buf)
1396{
1397        size_t len;
1398        if (!strip_suffix(pack_name, ".pack", &len))
1399                die(_("packfile name '%s' does not end with '.pack'"),
1400                    pack_name);
1401        strbuf_add(buf, pack_name, len);
1402        strbuf_addch(buf, '.');
1403        strbuf_addstr(buf, suffix);
1404        return buf->buf;
1405}
1406
1407static void write_special_file(const char *suffix, const char *msg,
1408                               const char *pack_name, const unsigned char *hash,
1409                               const char **report)
1410{
1411        struct strbuf name_buf = STRBUF_INIT;
1412        const char *filename;
1413        int fd;
1414        int msg_len = strlen(msg);
1415
1416        if (pack_name)
1417                filename = derive_filename(pack_name, suffix, &name_buf);
1418        else
1419                filename = odb_pack_name(&name_buf, hash, suffix);
1420
1421        fd = odb_pack_keep(filename);
1422        if (fd < 0) {
1423                if (errno != EEXIST)
1424                        die_errno(_("cannot write %s file '%s'"),
1425                                  suffix, filename);
1426        } else {
1427                if (msg_len > 0) {
1428                        write_or_die(fd, msg, msg_len);
1429                        write_or_die(fd, "\n", 1);
1430                }
1431                if (close(fd) != 0)
1432                        die_errno(_("cannot close written %s file '%s'"),
1433                                  suffix, filename);
1434                if (report)
1435                        *report = suffix;
1436        }
1437        strbuf_release(&name_buf);
1438}
1439
1440static void final(const char *final_pack_name, const char *curr_pack_name,
1441                  const char *final_index_name, const char *curr_index_name,
1442                  const char *keep_msg, const char *promisor_msg,
1443                  unsigned char *hash)
1444{
1445        const char *report = "pack";
1446        struct strbuf pack_name = STRBUF_INIT;
1447        struct strbuf index_name = STRBUF_INIT;
1448        int err;
1449
1450        if (!from_stdin) {
1451                close(input_fd);
1452        } else {
1453                fsync_or_die(output_fd, curr_pack_name);
1454                err = close(output_fd);
1455                if (err)
1456                        die_errno(_("error while closing pack file"));
1457        }
1458
1459        if (keep_msg)
1460                write_special_file("keep", keep_msg, final_pack_name, hash,
1461                                   &report);
1462        if (promisor_msg)
1463                write_special_file("promisor", promisor_msg, final_pack_name,
1464                                   hash, NULL);
1465
1466        if (final_pack_name != curr_pack_name) {
1467                if (!final_pack_name)
1468                        final_pack_name = odb_pack_name(&pack_name, hash, "pack");
1469                if (finalize_object_file(curr_pack_name, final_pack_name))
1470                        die(_("cannot store pack file"));
1471        } else if (from_stdin)
1472                chmod(final_pack_name, 0444);
1473
1474        if (final_index_name != curr_index_name) {
1475                if (!final_index_name)
1476                        final_index_name = odb_pack_name(&index_name, hash, "idx");
1477                if (finalize_object_file(curr_index_name, final_index_name))
1478                        die(_("cannot store index file"));
1479        } else
1480                chmod(final_index_name, 0444);
1481
1482        if (!from_stdin) {
1483                printf("%s\n", sha1_to_hex(hash));
1484        } else {
1485                struct strbuf buf = STRBUF_INIT;
1486
1487                strbuf_addf(&buf, "%s\t%s\n", report, sha1_to_hex(hash));
1488                write_or_die(1, buf.buf, buf.len);
1489                strbuf_release(&buf);
1490
1491                /*
1492                 * Let's just mimic git-unpack-objects here and write
1493                 * the last part of the input buffer to stdout.
1494                 */
1495                while (input_len) {
1496                        err = xwrite(1, input_buffer + input_offset, input_len);
1497                        if (err <= 0)
1498                                break;
1499                        input_len -= err;
1500                        input_offset += err;
1501                }
1502        }
1503
1504        strbuf_release(&index_name);
1505        strbuf_release(&pack_name);
1506}
1507
1508static int git_index_pack_config(const char *k, const char *v, void *cb)
1509{
1510        struct pack_idx_option *opts = cb;
1511
1512        if (!strcmp(k, "pack.indexversion")) {
1513                opts->version = git_config_int(k, v);
1514                if (opts->version > 2)
1515                        die(_("bad pack.indexversion=%"PRIu32), opts->version);
1516                return 0;
1517        }
1518        if (!strcmp(k, "pack.threads")) {
1519                nr_threads = git_config_int(k, v);
1520                if (nr_threads < 0)
1521                        die(_("invalid number of threads specified (%d)"),
1522                            nr_threads);
1523#ifdef NO_PTHREADS
1524                if (nr_threads != 1)
1525                        warning(_("no threads support, ignoring %s"), k);
1526                nr_threads = 1;
1527#endif
1528                return 0;
1529        }
1530        return git_default_config(k, v, cb);
1531}
1532
1533static int cmp_uint32(const void *a_, const void *b_)
1534{
1535        uint32_t a = *((uint32_t *)a_);
1536        uint32_t b = *((uint32_t *)b_);
1537
1538        return (a < b) ? -1 : (a != b);
1539}
1540
1541static void read_v2_anomalous_offsets(struct packed_git *p,
1542                                      struct pack_idx_option *opts)
1543{
1544        const uint32_t *idx1, *idx2;
1545        uint32_t i;
1546
1547        /* The address of the 4-byte offset table */
1548        idx1 = (((const uint32_t *)p->index_data)
1549                + 2 /* 8-byte header */
1550                + 256 /* fan out */
1551                + 5 * p->num_objects /* 20-byte SHA-1 table */
1552                + p->num_objects /* CRC32 table */
1553                );
1554
1555        /* The address of the 8-byte offset table */
1556        idx2 = idx1 + p->num_objects;
1557
1558        for (i = 0; i < p->num_objects; i++) {
1559                uint32_t off = ntohl(idx1[i]);
1560                if (!(off & 0x80000000))
1561                        continue;
1562                off = off & 0x7fffffff;
1563                check_pack_index_ptr(p, &idx2[off * 2]);
1564                if (idx2[off * 2])
1565                        continue;
1566                /*
1567                 * The real offset is ntohl(idx2[off * 2]) in high 4
1568                 * octets, and ntohl(idx2[off * 2 + 1]) in low 4
1569                 * octets.  But idx2[off * 2] is Zero!!!
1570                 */
1571                ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
1572                opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
1573        }
1574
1575        QSORT(opts->anomaly, opts->anomaly_nr, cmp_uint32);
1576}
1577
1578static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
1579{
1580        struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
1581
1582        if (!p)
1583                die(_("Cannot open existing pack file '%s'"), pack_name);
1584        if (open_pack_index(p))
1585                die(_("Cannot open existing pack idx file for '%s'"), pack_name);
1586
1587        /* Read the attributes from the existing idx file */
1588        opts->version = p->index_version;
1589
1590        if (opts->version == 2)
1591                read_v2_anomalous_offsets(p, opts);
1592
1593        /*
1594         * Get rid of the idx file as we do not need it anymore.
1595         * NEEDSWORK: extract this bit from free_pack_by_name() in
1596         * sha1_file.c, perhaps?  It shouldn't matter very much as we
1597         * know we haven't installed this pack (hence we never have
1598         * read anything from it).
1599         */
1600        close_pack_index(p);
1601        free(p);
1602}
1603
1604static void show_pack_info(int stat_only)
1605{
1606        int i, baseobjects = nr_objects - nr_ref_deltas - nr_ofs_deltas;
1607        unsigned long *chain_histogram = NULL;
1608
1609        if (deepest_delta)
1610                chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
1611
1612        for (i = 0; i < nr_objects; i++) {
1613                struct object_entry *obj = &objects[i];
1614
1615                if (is_delta_type(obj->type))
1616                        chain_histogram[obj_stat[i].delta_depth - 1]++;
1617                if (stat_only)
1618                        continue;
1619                printf("%s %-6s %lu %lu %"PRIuMAX,
1620                       oid_to_hex(&obj->idx.oid),
1621                       type_name(obj->real_type), obj->size,
1622                       (unsigned long)(obj[1].idx.offset - obj->idx.offset),
1623                       (uintmax_t)obj->idx.offset);
1624                if (is_delta_type(obj->type)) {
1625                        struct object_entry *bobj = &objects[obj_stat[i].base_object_no];
1626                        printf(" %u %s", obj_stat[i].delta_depth,
1627                               oid_to_hex(&bobj->idx.oid));
1628                }
1629                putchar('\n');
1630        }
1631
1632        if (baseobjects)
1633                printf_ln(Q_("non delta: %d object",
1634                             "non delta: %d objects",
1635                             baseobjects),
1636                          baseobjects);
1637        for (i = 0; i < deepest_delta; i++) {
1638                if (!chain_histogram[i])
1639                        continue;
1640                printf_ln(Q_("chain length = %d: %lu object",
1641                             "chain length = %d: %lu objects",
1642                             chain_histogram[i]),
1643                          i + 1,
1644                          chain_histogram[i]);
1645        }
1646}
1647
1648int cmd_index_pack(int argc, const char **argv, const char *prefix)
1649{
1650        int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
1651        const char *curr_index;
1652        const char *index_name = NULL, *pack_name = NULL;
1653        const char *keep_msg = NULL;
1654        const char *promisor_msg = NULL;
1655        struct strbuf index_name_buf = STRBUF_INIT;
1656        struct pack_idx_entry **idx_objects;
1657        struct pack_idx_option opts;
1658        unsigned char pack_hash[GIT_MAX_RAWSZ];
1659        unsigned foreign_nr = 1;        /* zero is a "good" value, assume bad */
1660        int report_end_of_input = 0;
1661
1662        /*
1663         * index-pack never needs to fetch missing objects, since it only
1664         * accesses the repo to do hash collision checks
1665         */
1666        fetch_if_missing = 0;
1667
1668        if (argc == 2 && !strcmp(argv[1], "-h"))
1669                usage(index_pack_usage);
1670
1671        check_replace_refs = 0;
1672        fsck_options.walk = mark_link;
1673
1674        reset_pack_idx_option(&opts);
1675        git_config(git_index_pack_config, &opts);
1676        if (prefix && chdir(prefix))
1677                die(_("Cannot come back to cwd"));
1678
1679        for (i = 1; i < argc; i++) {
1680                const char *arg = argv[i];
1681
1682                if (*arg == '-') {
1683                        if (!strcmp(arg, "--stdin")) {
1684                                from_stdin = 1;
1685                        } else if (!strcmp(arg, "--fix-thin")) {
1686                                fix_thin_pack = 1;
1687                        } else if (skip_to_optional_arg(arg, "--strict", &arg)) {
1688                                strict = 1;
1689                                do_fsck_object = 1;
1690                                fsck_set_msg_types(&fsck_options, arg);
1691                        } else if (!strcmp(arg, "--check-self-contained-and-connected")) {
1692                                strict = 1;
1693                                check_self_contained_and_connected = 1;
1694                        } else if (!strcmp(arg, "--fsck-objects")) {
1695                                do_fsck_object = 1;
1696                        } else if (!strcmp(arg, "--verify")) {
1697                                verify = 1;
1698                        } else if (!strcmp(arg, "--verify-stat")) {
1699                                verify = 1;
1700                                show_stat = 1;
1701                        } else if (!strcmp(arg, "--verify-stat-only")) {
1702                                verify = 1;
1703                                show_stat = 1;
1704                                stat_only = 1;
1705                        } else if (skip_to_optional_arg(arg, "--keep", &keep_msg)) {
1706                                ; /* nothing to do */
1707                        } else if (skip_to_optional_arg(arg, "--promisor", &promisor_msg)) {
1708                                ; /* already parsed */
1709                        } else if (starts_with(arg, "--threads=")) {
1710                                char *end;
1711                                nr_threads = strtoul(arg+10, &end, 0);
1712                                if (!arg[10] || *end || nr_threads < 0)
1713                                        usage(index_pack_usage);
1714#ifdef NO_PTHREADS
1715                                if (nr_threads != 1)
1716                                        warning(_("no threads support, "
1717                                                  "ignoring %s"), arg);
1718                                nr_threads = 1;
1719#endif
1720                        } else if (starts_with(arg, "--pack_header=")) {
1721                                struct pack_header *hdr;
1722                                char *c;
1723
1724                                hdr = (struct pack_header *)input_buffer;
1725                                hdr->hdr_signature = htonl(PACK_SIGNATURE);
1726                                hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
1727                                if (*c != ',')
1728                                        die(_("bad %s"), arg);
1729                                hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
1730                                if (*c)
1731                                        die(_("bad %s"), arg);
1732                                input_len = sizeof(*hdr);
1733                        } else if (!strcmp(arg, "-v")) {
1734                                verbose = 1;
1735                        } else if (!strcmp(arg, "--show-resolving-progress")) {
1736                                show_resolving_progress = 1;
1737                        } else if (!strcmp(arg, "--report-end-of-input")) {
1738                                report_end_of_input = 1;
1739                        } else if (!strcmp(arg, "-o")) {
1740                                if (index_name || (i+1) >= argc)
1741                                        usage(index_pack_usage);
1742                                index_name = argv[++i];
1743                        } else if (starts_with(arg, "--index-version=")) {
1744                                char *c;
1745                                opts.version = strtoul(arg + 16, &c, 10);
1746                                if (opts.version > 2)
1747                                        die(_("bad %s"), arg);
1748                                if (*c == ',')
1749                                        opts.off32_limit = strtoul(c+1, &c, 0);
1750                                if (*c || opts.off32_limit & 0x80000000)
1751                                        die(_("bad %s"), arg);
1752                        } else if (skip_prefix(arg, "--max-input-size=", &arg)) {
1753                                max_input_size = strtoumax(arg, NULL, 10);
1754                        } else
1755                                usage(index_pack_usage);
1756                        continue;
1757                }
1758
1759                if (pack_name)
1760                        usage(index_pack_usage);
1761                pack_name = arg;
1762        }
1763
1764        if (!pack_name && !from_stdin)
1765                usage(index_pack_usage);
1766        if (fix_thin_pack && !from_stdin)
1767                die(_("--fix-thin cannot be used without --stdin"));
1768        if (from_stdin && !startup_info->have_repository)
1769                die(_("--stdin requires a git repository"));
1770        if (!index_name && pack_name)
1771                index_name = derive_filename(pack_name, "idx", &index_name_buf);
1772
1773        if (verify) {
1774                if (!index_name)
1775                        die(_("--verify with no packfile name given"));
1776                read_idx_option(&opts, index_name);
1777                opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
1778        }
1779        if (strict)
1780                opts.flags |= WRITE_IDX_STRICT;
1781
1782#ifndef NO_PTHREADS
1783        if (!nr_threads) {
1784                nr_threads = online_cpus();
1785                /* An experiment showed that more threads does not mean faster */
1786                if (nr_threads > 3)
1787                        nr_threads = 3;
1788        }
1789#endif
1790
1791        curr_pack = open_pack_file(pack_name);
1792        parse_pack_header();
1793        objects = xcalloc(st_add(nr_objects, 1), sizeof(struct object_entry));
1794        if (show_stat)
1795                obj_stat = xcalloc(st_add(nr_objects, 1), sizeof(struct object_stat));
1796        ofs_deltas = xcalloc(nr_objects, sizeof(struct ofs_delta_entry));
1797        parse_pack_objects(pack_hash);
1798        if (report_end_of_input)
1799                write_in_full(2, "\0", 1);
1800        resolve_deltas();
1801        conclude_pack(fix_thin_pack, curr_pack, pack_hash);
1802        free(ofs_deltas);
1803        free(ref_deltas);
1804        if (strict)
1805                foreign_nr = check_objects();
1806
1807        if (show_stat)
1808                show_pack_info(stat_only);
1809
1810        ALLOC_ARRAY(idx_objects, nr_objects);
1811        for (i = 0; i < nr_objects; i++)
1812                idx_objects[i] = &objects[i].idx;
1813        curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_hash);
1814        free(idx_objects);
1815
1816        if (!verify)
1817                final(pack_name, curr_pack,
1818                      index_name, curr_index,
1819                      keep_msg, promisor_msg,
1820                      pack_hash);
1821        else
1822                close(input_fd);
1823        free(objects);
1824        strbuf_release(&index_name_buf);
1825        if (pack_name == NULL)
1826                free((void *) curr_pack);
1827        if (index_name == NULL)
1828                free((void *) curr_index);
1829
1830        /*
1831         * Let the caller know this pack is not self contained
1832         */
1833        if (check_self_contained_and_connected && foreign_nr)
1834                return 1;
1835
1836        return 0;
1837}