411aefd6875b2d35ee4a12d1a043ba50027021b3
   1#include "builtin.h"
   2#include "cache.h"
   3#include "repository.h"
   4#include "config.h"
   5#include "attr.h"
   6#include "object.h"
   7#include "blob.h"
   8#include "commit.h"
   9#include "tag.h"
  10#include "tree.h"
  11#include "delta.h"
  12#include "pack.h"
  13#include "pack-revindex.h"
  14#include "csum-file.h"
  15#include "tree-walk.h"
  16#include "diff.h"
  17#include "revision.h"
  18#include "list-objects.h"
  19#include "list-objects-filter.h"
  20#include "list-objects-filter-options.h"
  21#include "pack-objects.h"
  22#include "progress.h"
  23#include "refs.h"
  24#include "streaming.h"
  25#include "thread-utils.h"
  26#include "pack-bitmap.h"
  27#include "delta-islands.h"
  28#include "reachable.h"
  29#include "sha1-array.h"
  30#include "argv-array.h"
  31#include "list.h"
  32#include "packfile.h"
  33#include "object-store.h"
  34#include "dir.h"
  35#include "midx.h"
  36
  37#define IN_PACK(obj) oe_in_pack(&to_pack, obj)
  38#define SIZE(obj) oe_size(&to_pack, obj)
  39#define SET_SIZE(obj,size) oe_set_size(&to_pack, obj, size)
  40#define DELTA_SIZE(obj) oe_delta_size(&to_pack, obj)
  41#define DELTA(obj) oe_delta(&to_pack, obj)
  42#define DELTA_CHILD(obj) oe_delta_child(&to_pack, obj)
  43#define DELTA_SIBLING(obj) oe_delta_sibling(&to_pack, obj)
  44#define SET_DELTA(obj, val) oe_set_delta(&to_pack, obj, val)
  45#define SET_DELTA_EXT(obj, oid) oe_set_delta_ext(&to_pack, obj, oid)
  46#define SET_DELTA_SIZE(obj, val) oe_set_delta_size(&to_pack, obj, val)
  47#define SET_DELTA_CHILD(obj, val) oe_set_delta_child(&to_pack, obj, val)
  48#define SET_DELTA_SIBLING(obj, val) oe_set_delta_sibling(&to_pack, obj, val)
  49
  50static const char *pack_usage[] = {
  51        N_("git pack-objects --stdout [<options>...] [< <ref-list> | < <object-list>]"),
  52        N_("git pack-objects [<options>...] <base-name> [< <ref-list> | < <object-list>]"),
  53        NULL
  54};
  55
  56/*
  57 * Objects we are going to pack are collected in the `to_pack` structure.
  58 * It contains an array (dynamically expanded) of the object data, and a map
  59 * that can resolve SHA1s to their position in the array.
  60 */
  61static struct packing_data to_pack;
  62
  63static struct pack_idx_entry **written_list;
  64static uint32_t nr_result, nr_written, nr_seen;
  65static struct bitmap_index *bitmap_git;
  66static uint32_t write_layer;
  67
  68static int non_empty;
  69static int reuse_delta = 1, reuse_object = 1;
  70static int keep_unreachable, unpack_unreachable, include_tag;
  71static timestamp_t unpack_unreachable_expiration;
  72static int pack_loose_unreachable;
  73static int local;
  74static int have_non_local_packs;
  75static int incremental;
  76static int ignore_packed_keep_on_disk;
  77static int ignore_packed_keep_in_core;
  78static int allow_ofs_delta;
  79static struct pack_idx_option pack_idx_opts;
  80static const char *base_name;
  81static int progress = 1;
  82static int window = 10;
  83static unsigned long pack_size_limit;
  84static int depth = 50;
  85static int delta_search_threads;
  86static int pack_to_stdout;
  87static int thin;
  88static int num_preferred_base;
  89static struct progress *progress_state;
  90
  91static struct packed_git *reuse_packfile;
  92static uint32_t reuse_packfile_objects;
  93static off_t reuse_packfile_offset;
  94
  95static int use_bitmap_index_default = 1;
  96static int use_bitmap_index = -1;
  97static int write_bitmap_index;
  98static uint16_t write_bitmap_options;
  99
 100static int exclude_promisor_objects;
 101
 102static int use_delta_islands;
 103
 104static unsigned long delta_cache_size = 0;
 105static unsigned long max_delta_cache_size = DEFAULT_DELTA_CACHE_SIZE;
 106static unsigned long cache_max_small_delta_size = 1000;
 107
 108static unsigned long window_memory_limit = 0;
 109
 110static struct list_objects_filter_options filter_options;
 111
 112enum missing_action {
 113        MA_ERROR = 0,      /* fail if any missing objects are encountered */
 114        MA_ALLOW_ANY,      /* silently allow ALL missing objects */
 115        MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
 116};
 117static enum missing_action arg_missing_action;
 118static show_object_fn fn_show_object;
 119
 120/*
 121 * stats
 122 */
 123static uint32_t written, written_delta;
 124static uint32_t reused, reused_delta;
 125
 126/*
 127 * Indexed commits
 128 */
 129static struct commit **indexed_commits;
 130static unsigned int indexed_commits_nr;
 131static unsigned int indexed_commits_alloc;
 132
 133static void index_commit_for_bitmap(struct commit *commit)
 134{
 135        if (indexed_commits_nr >= indexed_commits_alloc) {
 136                indexed_commits_alloc = (indexed_commits_alloc + 32) * 2;
 137                REALLOC_ARRAY(indexed_commits, indexed_commits_alloc);
 138        }
 139
 140        indexed_commits[indexed_commits_nr++] = commit;
 141}
 142
 143static void *get_delta(struct object_entry *entry)
 144{
 145        unsigned long size, base_size, delta_size;
 146        void *buf, *base_buf, *delta_buf;
 147        enum object_type type;
 148
 149        buf = read_object_file(&entry->idx.oid, &type, &size);
 150        if (!buf)
 151                die(_("unable to read %s"), oid_to_hex(&entry->idx.oid));
 152        base_buf = read_object_file(&DELTA(entry)->idx.oid, &type,
 153                                    &base_size);
 154        if (!base_buf)
 155                die("unable to read %s",
 156                    oid_to_hex(&DELTA(entry)->idx.oid));
 157        delta_buf = diff_delta(base_buf, base_size,
 158                               buf, size, &delta_size, 0);
 159        /*
 160         * We succesfully computed this delta once but dropped it for
 161         * memory reasons. Something is very wrong if this time we
 162         * recompute and create a different delta.
 163         */
 164        if (!delta_buf || delta_size != DELTA_SIZE(entry))
 165                BUG("delta size changed");
 166        free(buf);
 167        free(base_buf);
 168        return delta_buf;
 169}
 170
 171static unsigned long do_compress(void **pptr, unsigned long size)
 172{
 173        git_zstream stream;
 174        void *in, *out;
 175        unsigned long maxsize;
 176
 177        git_deflate_init(&stream, pack_compression_level);
 178        maxsize = git_deflate_bound(&stream, size);
 179
 180        in = *pptr;
 181        out = xmalloc(maxsize);
 182        *pptr = out;
 183
 184        stream.next_in = in;
 185        stream.avail_in = size;
 186        stream.next_out = out;
 187        stream.avail_out = maxsize;
 188        while (git_deflate(&stream, Z_FINISH) == Z_OK)
 189                ; /* nothing */
 190        git_deflate_end(&stream);
 191
 192        free(in);
 193        return stream.total_out;
 194}
 195
 196static unsigned long write_large_blob_data(struct git_istream *st, struct hashfile *f,
 197                                           const struct object_id *oid)
 198{
 199        git_zstream stream;
 200        unsigned char ibuf[1024 * 16];
 201        unsigned char obuf[1024 * 16];
 202        unsigned long olen = 0;
 203
 204        git_deflate_init(&stream, pack_compression_level);
 205
 206        for (;;) {
 207                ssize_t readlen;
 208                int zret = Z_OK;
 209                readlen = read_istream(st, ibuf, sizeof(ibuf));
 210                if (readlen == -1)
 211                        die(_("unable to read %s"), oid_to_hex(oid));
 212
 213                stream.next_in = ibuf;
 214                stream.avail_in = readlen;
 215                while ((stream.avail_in || readlen == 0) &&
 216                       (zret == Z_OK || zret == Z_BUF_ERROR)) {
 217                        stream.next_out = obuf;
 218                        stream.avail_out = sizeof(obuf);
 219                        zret = git_deflate(&stream, readlen ? 0 : Z_FINISH);
 220                        hashwrite(f, obuf, stream.next_out - obuf);
 221                        olen += stream.next_out - obuf;
 222                }
 223                if (stream.avail_in)
 224                        die(_("deflate error (%d)"), zret);
 225                if (readlen == 0) {
 226                        if (zret != Z_STREAM_END)
 227                                die(_("deflate error (%d)"), zret);
 228                        break;
 229                }
 230        }
 231        git_deflate_end(&stream);
 232        return olen;
 233}
 234
 235/*
 236 * we are going to reuse the existing object data as is.  make
 237 * sure it is not corrupt.
 238 */
 239static int check_pack_inflate(struct packed_git *p,
 240                struct pack_window **w_curs,
 241                off_t offset,
 242                off_t len,
 243                unsigned long expect)
 244{
 245        git_zstream stream;
 246        unsigned char fakebuf[4096], *in;
 247        int st;
 248
 249        memset(&stream, 0, sizeof(stream));
 250        git_inflate_init(&stream);
 251        do {
 252                in = use_pack(p, w_curs, offset, &stream.avail_in);
 253                stream.next_in = in;
 254                stream.next_out = fakebuf;
 255                stream.avail_out = sizeof(fakebuf);
 256                st = git_inflate(&stream, Z_FINISH);
 257                offset += stream.next_in - in;
 258        } while (st == Z_OK || st == Z_BUF_ERROR);
 259        git_inflate_end(&stream);
 260        return (st == Z_STREAM_END &&
 261                stream.total_out == expect &&
 262                stream.total_in == len) ? 0 : -1;
 263}
 264
 265static void copy_pack_data(struct hashfile *f,
 266                struct packed_git *p,
 267                struct pack_window **w_curs,
 268                off_t offset,
 269                off_t len)
 270{
 271        unsigned char *in;
 272        unsigned long avail;
 273
 274        while (len) {
 275                in = use_pack(p, w_curs, offset, &avail);
 276                if (avail > len)
 277                        avail = (unsigned long)len;
 278                hashwrite(f, in, avail);
 279                offset += avail;
 280                len -= avail;
 281        }
 282}
 283
 284/* Return 0 if we will bust the pack-size limit */
 285static unsigned long write_no_reuse_object(struct hashfile *f, struct object_entry *entry,
 286                                           unsigned long limit, int usable_delta)
 287{
 288        unsigned long size, datalen;
 289        unsigned char header[MAX_PACK_OBJECT_HEADER],
 290                      dheader[MAX_PACK_OBJECT_HEADER];
 291        unsigned hdrlen;
 292        enum object_type type;
 293        void *buf;
 294        struct git_istream *st = NULL;
 295        const unsigned hashsz = the_hash_algo->rawsz;
 296
 297        if (!usable_delta) {
 298                if (oe_type(entry) == OBJ_BLOB &&
 299                    oe_size_greater_than(&to_pack, entry, big_file_threshold) &&
 300                    (st = open_istream(&entry->idx.oid, &type, &size, NULL)) != NULL)
 301                        buf = NULL;
 302                else {
 303                        buf = read_object_file(&entry->idx.oid, &type, &size);
 304                        if (!buf)
 305                                die(_("unable to read %s"),
 306                                    oid_to_hex(&entry->idx.oid));
 307                }
 308                /*
 309                 * make sure no cached delta data remains from a
 310                 * previous attempt before a pack split occurred.
 311                 */
 312                FREE_AND_NULL(entry->delta_data);
 313                entry->z_delta_size = 0;
 314        } else if (entry->delta_data) {
 315                size = DELTA_SIZE(entry);
 316                buf = entry->delta_data;
 317                entry->delta_data = NULL;
 318                type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 319                        OBJ_OFS_DELTA : OBJ_REF_DELTA;
 320        } else {
 321                buf = get_delta(entry);
 322                size = DELTA_SIZE(entry);
 323                type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 324                        OBJ_OFS_DELTA : OBJ_REF_DELTA;
 325        }
 326
 327        if (st) /* large blob case, just assume we don't compress well */
 328                datalen = size;
 329        else if (entry->z_delta_size)
 330                datalen = entry->z_delta_size;
 331        else
 332                datalen = do_compress(&buf, size);
 333
 334        /*
 335         * The object header is a byte of 'type' followed by zero or
 336         * more bytes of length.
 337         */
 338        hdrlen = encode_in_pack_object_header(header, sizeof(header),
 339                                              type, size);
 340
 341        if (type == OBJ_OFS_DELTA) {
 342                /*
 343                 * Deltas with relative base contain an additional
 344                 * encoding of the relative offset for the delta
 345                 * base from this object's position in the pack.
 346                 */
 347                off_t ofs = entry->idx.offset - DELTA(entry)->idx.offset;
 348                unsigned pos = sizeof(dheader) - 1;
 349                dheader[pos] = ofs & 127;
 350                while (ofs >>= 7)
 351                        dheader[--pos] = 128 | (--ofs & 127);
 352                if (limit && hdrlen + sizeof(dheader) - pos + datalen + hashsz >= limit) {
 353                        if (st)
 354                                close_istream(st);
 355                        free(buf);
 356                        return 0;
 357                }
 358                hashwrite(f, header, hdrlen);
 359                hashwrite(f, dheader + pos, sizeof(dheader) - pos);
 360                hdrlen += sizeof(dheader) - pos;
 361        } else if (type == OBJ_REF_DELTA) {
 362                /*
 363                 * Deltas with a base reference contain
 364                 * additional bytes for the base object ID.
 365                 */
 366                if (limit && hdrlen + hashsz + datalen + hashsz >= limit) {
 367                        if (st)
 368                                close_istream(st);
 369                        free(buf);
 370                        return 0;
 371                }
 372                hashwrite(f, header, hdrlen);
 373                hashwrite(f, DELTA(entry)->idx.oid.hash, hashsz);
 374                hdrlen += hashsz;
 375        } else {
 376                if (limit && hdrlen + datalen + hashsz >= limit) {
 377                        if (st)
 378                                close_istream(st);
 379                        free(buf);
 380                        return 0;
 381                }
 382                hashwrite(f, header, hdrlen);
 383        }
 384        if (st) {
 385                datalen = write_large_blob_data(st, f, &entry->idx.oid);
 386                close_istream(st);
 387        } else {
 388                hashwrite(f, buf, datalen);
 389                free(buf);
 390        }
 391
 392        return hdrlen + datalen;
 393}
 394
 395/* Return 0 if we will bust the pack-size limit */
 396static off_t write_reuse_object(struct hashfile *f, struct object_entry *entry,
 397                                unsigned long limit, int usable_delta)
 398{
 399        struct packed_git *p = IN_PACK(entry);
 400        struct pack_window *w_curs = NULL;
 401        struct revindex_entry *revidx;
 402        off_t offset;
 403        enum object_type type = oe_type(entry);
 404        off_t datalen;
 405        unsigned char header[MAX_PACK_OBJECT_HEADER],
 406                      dheader[MAX_PACK_OBJECT_HEADER];
 407        unsigned hdrlen;
 408        const unsigned hashsz = the_hash_algo->rawsz;
 409        unsigned long entry_size = SIZE(entry);
 410
 411        if (DELTA(entry))
 412                type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 413                        OBJ_OFS_DELTA : OBJ_REF_DELTA;
 414        hdrlen = encode_in_pack_object_header(header, sizeof(header),
 415                                              type, entry_size);
 416
 417        offset = entry->in_pack_offset;
 418        revidx = find_pack_revindex(p, offset);
 419        datalen = revidx[1].offset - offset;
 420        if (!pack_to_stdout && p->index_version > 1 &&
 421            check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 422                error(_("bad packed object CRC for %s"),
 423                      oid_to_hex(&entry->idx.oid));
 424                unuse_pack(&w_curs);
 425                return write_no_reuse_object(f, entry, limit, usable_delta);
 426        }
 427
 428        offset += entry->in_pack_header_size;
 429        datalen -= entry->in_pack_header_size;
 430
 431        if (!pack_to_stdout && p->index_version == 1 &&
 432            check_pack_inflate(p, &w_curs, offset, datalen, entry_size)) {
 433                error(_("corrupt packed object for %s"),
 434                      oid_to_hex(&entry->idx.oid));
 435                unuse_pack(&w_curs);
 436                return write_no_reuse_object(f, entry, limit, usable_delta);
 437        }
 438
 439        if (type == OBJ_OFS_DELTA) {
 440                off_t ofs = entry->idx.offset - DELTA(entry)->idx.offset;
 441                unsigned pos = sizeof(dheader) - 1;
 442                dheader[pos] = ofs & 127;
 443                while (ofs >>= 7)
 444                        dheader[--pos] = 128 | (--ofs & 127);
 445                if (limit && hdrlen + sizeof(dheader) - pos + datalen + hashsz >= limit) {
 446                        unuse_pack(&w_curs);
 447                        return 0;
 448                }
 449                hashwrite(f, header, hdrlen);
 450                hashwrite(f, dheader + pos, sizeof(dheader) - pos);
 451                hdrlen += sizeof(dheader) - pos;
 452                reused_delta++;
 453        } else if (type == OBJ_REF_DELTA) {
 454                if (limit && hdrlen + hashsz + datalen + hashsz >= limit) {
 455                        unuse_pack(&w_curs);
 456                        return 0;
 457                }
 458                hashwrite(f, header, hdrlen);
 459                hashwrite(f, DELTA(entry)->idx.oid.hash, hashsz);
 460                hdrlen += hashsz;
 461                reused_delta++;
 462        } else {
 463                if (limit && hdrlen + datalen + hashsz >= limit) {
 464                        unuse_pack(&w_curs);
 465                        return 0;
 466                }
 467                hashwrite(f, header, hdrlen);
 468        }
 469        copy_pack_data(f, p, &w_curs, offset, datalen);
 470        unuse_pack(&w_curs);
 471        reused++;
 472        return hdrlen + datalen;
 473}
 474
 475/* Return 0 if we will bust the pack-size limit */
 476static off_t write_object(struct hashfile *f,
 477                          struct object_entry *entry,
 478                          off_t write_offset)
 479{
 480        unsigned long limit;
 481        off_t len;
 482        int usable_delta, to_reuse;
 483
 484        if (!pack_to_stdout)
 485                crc32_begin(f);
 486
 487        /* apply size limit if limited packsize and not first object */
 488        if (!pack_size_limit || !nr_written)
 489                limit = 0;
 490        else if (pack_size_limit <= write_offset)
 491                /*
 492                 * the earlier object did not fit the limit; avoid
 493                 * mistaking this with unlimited (i.e. limit = 0).
 494                 */
 495                limit = 1;
 496        else
 497                limit = pack_size_limit - write_offset;
 498
 499        if (!DELTA(entry))
 500                usable_delta = 0;       /* no delta */
 501        else if (!pack_size_limit)
 502               usable_delta = 1;        /* unlimited packfile */
 503        else if (DELTA(entry)->idx.offset == (off_t)-1)
 504                usable_delta = 0;       /* base was written to another pack */
 505        else if (DELTA(entry)->idx.offset)
 506                usable_delta = 1;       /* base already exists in this pack */
 507        else
 508                usable_delta = 0;       /* base could end up in another pack */
 509
 510        if (!reuse_object)
 511                to_reuse = 0;   /* explicit */
 512        else if (!IN_PACK(entry))
 513                to_reuse = 0;   /* can't reuse what we don't have */
 514        else if (oe_type(entry) == OBJ_REF_DELTA ||
 515                 oe_type(entry) == OBJ_OFS_DELTA)
 516                                /* check_object() decided it for us ... */
 517                to_reuse = usable_delta;
 518                                /* ... but pack split may override that */
 519        else if (oe_type(entry) != entry->in_pack_type)
 520                to_reuse = 0;   /* pack has delta which is unusable */
 521        else if (DELTA(entry))
 522                to_reuse = 0;   /* we want to pack afresh */
 523        else
 524                to_reuse = 1;   /* we have it in-pack undeltified,
 525                                 * and we do not need to deltify it.
 526                                 */
 527
 528        if (!to_reuse)
 529                len = write_no_reuse_object(f, entry, limit, usable_delta);
 530        else
 531                len = write_reuse_object(f, entry, limit, usable_delta);
 532        if (!len)
 533                return 0;
 534
 535        if (usable_delta)
 536                written_delta++;
 537        written++;
 538        if (!pack_to_stdout)
 539                entry->idx.crc32 = crc32_end(f);
 540        return len;
 541}
 542
 543enum write_one_status {
 544        WRITE_ONE_SKIP = -1, /* already written */
 545        WRITE_ONE_BREAK = 0, /* writing this will bust the limit; not written */
 546        WRITE_ONE_WRITTEN = 1, /* normal */
 547        WRITE_ONE_RECURSIVE = 2 /* already scheduled to be written */
 548};
 549
 550static enum write_one_status write_one(struct hashfile *f,
 551                                       struct object_entry *e,
 552                                       off_t *offset)
 553{
 554        off_t size;
 555        int recursing;
 556
 557        /*
 558         * we set offset to 1 (which is an impossible value) to mark
 559         * the fact that this object is involved in "write its base
 560         * first before writing a deltified object" recursion.
 561         */
 562        recursing = (e->idx.offset == 1);
 563        if (recursing) {
 564                warning(_("recursive delta detected for object %s"),
 565                        oid_to_hex(&e->idx.oid));
 566                return WRITE_ONE_RECURSIVE;
 567        } else if (e->idx.offset || e->preferred_base) {
 568                /* offset is non zero if object is written already. */
 569                return WRITE_ONE_SKIP;
 570        }
 571
 572        /* if we are deltified, write out base object first. */
 573        if (DELTA(e)) {
 574                e->idx.offset = 1; /* now recurse */
 575                switch (write_one(f, DELTA(e), offset)) {
 576                case WRITE_ONE_RECURSIVE:
 577                        /* we cannot depend on this one */
 578                        SET_DELTA(e, NULL);
 579                        break;
 580                default:
 581                        break;
 582                case WRITE_ONE_BREAK:
 583                        e->idx.offset = recursing;
 584                        return WRITE_ONE_BREAK;
 585                }
 586        }
 587
 588        e->idx.offset = *offset;
 589        size = write_object(f, e, *offset);
 590        if (!size) {
 591                e->idx.offset = recursing;
 592                return WRITE_ONE_BREAK;
 593        }
 594        written_list[nr_written++] = &e->idx;
 595
 596        /* make sure off_t is sufficiently large not to wrap */
 597        if (signed_add_overflows(*offset, size))
 598                die(_("pack too large for current definition of off_t"));
 599        *offset += size;
 600        return WRITE_ONE_WRITTEN;
 601}
 602
 603static int mark_tagged(const char *path, const struct object_id *oid, int flag,
 604                       void *cb_data)
 605{
 606        struct object_id peeled;
 607        struct object_entry *entry = packlist_find(&to_pack, oid->hash, NULL);
 608
 609        if (entry)
 610                entry->tagged = 1;
 611        if (!peel_ref(path, &peeled)) {
 612                entry = packlist_find(&to_pack, peeled.hash, NULL);
 613                if (entry)
 614                        entry->tagged = 1;
 615        }
 616        return 0;
 617}
 618
 619static inline void add_to_write_order(struct object_entry **wo,
 620                               unsigned int *endp,
 621                               struct object_entry *e)
 622{
 623        if (e->filled || oe_layer(&to_pack, e) != write_layer)
 624                return;
 625        wo[(*endp)++] = e;
 626        e->filled = 1;
 627}
 628
 629static void add_descendants_to_write_order(struct object_entry **wo,
 630                                           unsigned int *endp,
 631                                           struct object_entry *e)
 632{
 633        int add_to_order = 1;
 634        while (e) {
 635                if (add_to_order) {
 636                        struct object_entry *s;
 637                        /* add this node... */
 638                        add_to_write_order(wo, endp, e);
 639                        /* all its siblings... */
 640                        for (s = DELTA_SIBLING(e); s; s = DELTA_SIBLING(s)) {
 641                                add_to_write_order(wo, endp, s);
 642                        }
 643                }
 644                /* drop down a level to add left subtree nodes if possible */
 645                if (DELTA_CHILD(e)) {
 646                        add_to_order = 1;
 647                        e = DELTA_CHILD(e);
 648                } else {
 649                        add_to_order = 0;
 650                        /* our sibling might have some children, it is next */
 651                        if (DELTA_SIBLING(e)) {
 652                                e = DELTA_SIBLING(e);
 653                                continue;
 654                        }
 655                        /* go back to our parent node */
 656                        e = DELTA(e);
 657                        while (e && !DELTA_SIBLING(e)) {
 658                                /* we're on the right side of a subtree, keep
 659                                 * going up until we can go right again */
 660                                e = DELTA(e);
 661                        }
 662                        if (!e) {
 663                                /* done- we hit our original root node */
 664                                return;
 665                        }
 666                        /* pass it off to sibling at this level */
 667                        e = DELTA_SIBLING(e);
 668                }
 669        };
 670}
 671
 672static void add_family_to_write_order(struct object_entry **wo,
 673                                      unsigned int *endp,
 674                                      struct object_entry *e)
 675{
 676        struct object_entry *root;
 677
 678        for (root = e; DELTA(root); root = DELTA(root))
 679                ; /* nothing */
 680        add_descendants_to_write_order(wo, endp, root);
 681}
 682
 683static void compute_layer_order(struct object_entry **wo, unsigned int *wo_end)
 684{
 685        unsigned int i, last_untagged;
 686        struct object_entry *objects = to_pack.objects;
 687
 688        for (i = 0; i < to_pack.nr_objects; i++) {
 689                if (objects[i].tagged)
 690                        break;
 691                add_to_write_order(wo, wo_end, &objects[i]);
 692        }
 693        last_untagged = i;
 694
 695        /*
 696         * Then fill all the tagged tips.
 697         */
 698        for (; i < to_pack.nr_objects; i++) {
 699                if (objects[i].tagged)
 700                        add_to_write_order(wo, wo_end, &objects[i]);
 701        }
 702
 703        /*
 704         * And then all remaining commits and tags.
 705         */
 706        for (i = last_untagged; i < to_pack.nr_objects; i++) {
 707                if (oe_type(&objects[i]) != OBJ_COMMIT &&
 708                    oe_type(&objects[i]) != OBJ_TAG)
 709                        continue;
 710                add_to_write_order(wo, wo_end, &objects[i]);
 711        }
 712
 713        /*
 714         * And then all the trees.
 715         */
 716        for (i = last_untagged; i < to_pack.nr_objects; i++) {
 717                if (oe_type(&objects[i]) != OBJ_TREE)
 718                        continue;
 719                add_to_write_order(wo, wo_end, &objects[i]);
 720        }
 721
 722        /*
 723         * Finally all the rest in really tight order
 724         */
 725        for (i = last_untagged; i < to_pack.nr_objects; i++) {
 726                if (!objects[i].filled && oe_layer(&to_pack, &objects[i]) == write_layer)
 727                        add_family_to_write_order(wo, wo_end, &objects[i]);
 728        }
 729}
 730
 731static struct object_entry **compute_write_order(void)
 732{
 733        uint32_t max_layers = 1;
 734        unsigned int i, wo_end;
 735
 736        struct object_entry **wo;
 737        struct object_entry *objects = to_pack.objects;
 738
 739        for (i = 0; i < to_pack.nr_objects; i++) {
 740                objects[i].tagged = 0;
 741                objects[i].filled = 0;
 742                SET_DELTA_CHILD(&objects[i], NULL);
 743                SET_DELTA_SIBLING(&objects[i], NULL);
 744        }
 745
 746        /*
 747         * Fully connect delta_child/delta_sibling network.
 748         * Make sure delta_sibling is sorted in the original
 749         * recency order.
 750         */
 751        for (i = to_pack.nr_objects; i > 0;) {
 752                struct object_entry *e = &objects[--i];
 753                if (!DELTA(e))
 754                        continue;
 755                /* Mark me as the first child */
 756                e->delta_sibling_idx = DELTA(e)->delta_child_idx;
 757                SET_DELTA_CHILD(DELTA(e), e);
 758        }
 759
 760        /*
 761         * Mark objects that are at the tip of tags.
 762         */
 763        for_each_tag_ref(mark_tagged, NULL);
 764
 765        if (use_delta_islands)
 766                max_layers = compute_pack_layers(&to_pack);
 767
 768        ALLOC_ARRAY(wo, to_pack.nr_objects);
 769        wo_end = 0;
 770
 771        for (; write_layer < max_layers; ++write_layer)
 772                compute_layer_order(wo, &wo_end);
 773
 774        if (wo_end != to_pack.nr_objects)
 775                die(_("ordered %u objects, expected %"PRIu32),
 776                    wo_end, to_pack.nr_objects);
 777
 778        return wo;
 779}
 780
 781static off_t write_reused_pack(struct hashfile *f)
 782{
 783        unsigned char buffer[8192];
 784        off_t to_write, total;
 785        int fd;
 786
 787        if (!is_pack_valid(reuse_packfile))
 788                die(_("packfile is invalid: %s"), reuse_packfile->pack_name);
 789
 790        fd = git_open(reuse_packfile->pack_name);
 791        if (fd < 0)
 792                die_errno(_("unable to open packfile for reuse: %s"),
 793                          reuse_packfile->pack_name);
 794
 795        if (lseek(fd, sizeof(struct pack_header), SEEK_SET) == -1)
 796                die_errno(_("unable to seek in reused packfile"));
 797
 798        if (reuse_packfile_offset < 0)
 799                reuse_packfile_offset = reuse_packfile->pack_size - the_hash_algo->rawsz;
 800
 801        total = to_write = reuse_packfile_offset - sizeof(struct pack_header);
 802
 803        while (to_write) {
 804                int read_pack = xread(fd, buffer, sizeof(buffer));
 805
 806                if (read_pack <= 0)
 807                        die_errno(_("unable to read from reused packfile"));
 808
 809                if (read_pack > to_write)
 810                        read_pack = to_write;
 811
 812                hashwrite(f, buffer, read_pack);
 813                to_write -= read_pack;
 814
 815                /*
 816                 * We don't know the actual number of objects written,
 817                 * only how many bytes written, how many bytes total, and
 818                 * how many objects total. So we can fake it by pretending all
 819                 * objects we are writing are the same size. This gives us a
 820                 * smooth progress meter, and at the end it matches the true
 821                 * answer.
 822                 */
 823                written = reuse_packfile_objects *
 824                                (((double)(total - to_write)) / total);
 825                display_progress(progress_state, written);
 826        }
 827
 828        close(fd);
 829        written = reuse_packfile_objects;
 830        display_progress(progress_state, written);
 831        return reuse_packfile_offset - sizeof(struct pack_header);
 832}
 833
 834static const char no_split_warning[] = N_(
 835"disabling bitmap writing, packs are split due to pack.packSizeLimit"
 836);
 837
 838static void write_pack_file(void)
 839{
 840        uint32_t i = 0, j;
 841        struct hashfile *f;
 842        off_t offset;
 843        uint32_t nr_remaining = nr_result;
 844        time_t last_mtime = 0;
 845        struct object_entry **write_order;
 846
 847        if (progress > pack_to_stdout)
 848                progress_state = start_progress(_("Writing objects"), nr_result);
 849        ALLOC_ARRAY(written_list, to_pack.nr_objects);
 850        write_order = compute_write_order();
 851
 852        do {
 853                struct object_id oid;
 854                char *pack_tmp_name = NULL;
 855
 856                if (pack_to_stdout)
 857                        f = hashfd_throughput(1, "<stdout>", progress_state);
 858                else
 859                        f = create_tmp_packfile(&pack_tmp_name);
 860
 861                offset = write_pack_header(f, nr_remaining);
 862
 863                if (reuse_packfile) {
 864                        off_t packfile_size;
 865                        assert(pack_to_stdout);
 866
 867                        packfile_size = write_reused_pack(f);
 868                        offset += packfile_size;
 869                }
 870
 871                nr_written = 0;
 872                for (; i < to_pack.nr_objects; i++) {
 873                        struct object_entry *e = write_order[i];
 874                        if (write_one(f, e, &offset) == WRITE_ONE_BREAK)
 875                                break;
 876                        display_progress(progress_state, written);
 877                }
 878
 879                /*
 880                 * Did we write the wrong # entries in the header?
 881                 * If so, rewrite it like in fast-import
 882                 */
 883                if (pack_to_stdout) {
 884                        finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_CLOSE);
 885                } else if (nr_written == nr_remaining) {
 886                        finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
 887                } else {
 888                        int fd = finalize_hashfile(f, oid.hash, 0);
 889                        fixup_pack_header_footer(fd, oid.hash, pack_tmp_name,
 890                                                 nr_written, oid.hash, offset);
 891                        close(fd);
 892                        if (write_bitmap_index) {
 893                                warning(_(no_split_warning));
 894                                write_bitmap_index = 0;
 895                        }
 896                }
 897
 898                if (!pack_to_stdout) {
 899                        struct stat st;
 900                        struct strbuf tmpname = STRBUF_INIT;
 901
 902                        /*
 903                         * Packs are runtime accessed in their mtime
 904                         * order since newer packs are more likely to contain
 905                         * younger objects.  So if we are creating multiple
 906                         * packs then we should modify the mtime of later ones
 907                         * to preserve this property.
 908                         */
 909                        if (stat(pack_tmp_name, &st) < 0) {
 910                                warning_errno(_("failed to stat %s"), pack_tmp_name);
 911                        } else if (!last_mtime) {
 912                                last_mtime = st.st_mtime;
 913                        } else {
 914                                struct utimbuf utb;
 915                                utb.actime = st.st_atime;
 916                                utb.modtime = --last_mtime;
 917                                if (utime(pack_tmp_name, &utb) < 0)
 918                                        warning_errno(_("failed utime() on %s"), pack_tmp_name);
 919                        }
 920
 921                        strbuf_addf(&tmpname, "%s-", base_name);
 922
 923                        if (write_bitmap_index) {
 924                                bitmap_writer_set_checksum(oid.hash);
 925                                bitmap_writer_build_type_index(
 926                                        &to_pack, written_list, nr_written);
 927                        }
 928
 929                        finish_tmp_packfile(&tmpname, pack_tmp_name,
 930                                            written_list, nr_written,
 931                                            &pack_idx_opts, oid.hash);
 932
 933                        if (write_bitmap_index) {
 934                                strbuf_addf(&tmpname, "%s.bitmap", oid_to_hex(&oid));
 935
 936                                stop_progress(&progress_state);
 937
 938                                bitmap_writer_show_progress(progress);
 939                                bitmap_writer_reuse_bitmaps(&to_pack);
 940                                bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
 941                                bitmap_writer_build(&to_pack);
 942                                bitmap_writer_finish(written_list, nr_written,
 943                                                     tmpname.buf, write_bitmap_options);
 944                                write_bitmap_index = 0;
 945                        }
 946
 947                        strbuf_release(&tmpname);
 948                        free(pack_tmp_name);
 949                        puts(oid_to_hex(&oid));
 950                }
 951
 952                /* mark written objects as written to previous pack */
 953                for (j = 0; j < nr_written; j++) {
 954                        written_list[j]->offset = (off_t)-1;
 955                }
 956                nr_remaining -= nr_written;
 957        } while (nr_remaining && i < to_pack.nr_objects);
 958
 959        free(written_list);
 960        free(write_order);
 961        stop_progress(&progress_state);
 962        if (written != nr_result)
 963                die(_("wrote %"PRIu32" objects while expecting %"PRIu32),
 964                    written, nr_result);
 965}
 966
 967static int no_try_delta(const char *path)
 968{
 969        static struct attr_check *check;
 970
 971        if (!check)
 972                check = attr_check_initl("delta", NULL);
 973        git_check_attr(&the_index, path, check);
 974        if (ATTR_FALSE(check->items[0].value))
 975                return 1;
 976        return 0;
 977}
 978
 979/*
 980 * When adding an object, check whether we have already added it
 981 * to our packing list. If so, we can skip. However, if we are
 982 * being asked to excludei t, but the previous mention was to include
 983 * it, make sure to adjust its flags and tweak our numbers accordingly.
 984 *
 985 * As an optimization, we pass out the index position where we would have
 986 * found the item, since that saves us from having to look it up again a
 987 * few lines later when we want to add the new entry.
 988 */
 989static int have_duplicate_entry(const struct object_id *oid,
 990                                int exclude,
 991                                uint32_t *index_pos)
 992{
 993        struct object_entry *entry;
 994
 995        entry = packlist_find(&to_pack, oid->hash, index_pos);
 996        if (!entry)
 997                return 0;
 998
 999        if (exclude) {
1000                if (!entry->preferred_base)
1001                        nr_result--;
1002                entry->preferred_base = 1;
1003        }
1004
1005        return 1;
1006}
1007
1008static int want_found_object(int exclude, struct packed_git *p)
1009{
1010        if (exclude)
1011                return 1;
1012        if (incremental)
1013                return 0;
1014
1015        /*
1016         * When asked to do --local (do not include an object that appears in a
1017         * pack we borrow from elsewhere) or --honor-pack-keep (do not include
1018         * an object that appears in a pack marked with .keep), finding a pack
1019         * that matches the criteria is sufficient for us to decide to omit it.
1020         * However, even if this pack does not satisfy the criteria, we need to
1021         * make sure no copy of this object appears in _any_ pack that makes us
1022         * to omit the object, so we need to check all the packs.
1023         *
1024         * We can however first check whether these options can possible matter;
1025         * if they do not matter we know we want the object in generated pack.
1026         * Otherwise, we signal "-1" at the end to tell the caller that we do
1027         * not know either way, and it needs to check more packs.
1028         */
1029        if (!ignore_packed_keep_on_disk &&
1030            !ignore_packed_keep_in_core &&
1031            (!local || !have_non_local_packs))
1032                return 1;
1033
1034        if (local && !p->pack_local)
1035                return 0;
1036        if (p->pack_local &&
1037            ((ignore_packed_keep_on_disk && p->pack_keep) ||
1038             (ignore_packed_keep_in_core && p->pack_keep_in_core)))
1039                return 0;
1040
1041        /* we don't know yet; keep looking for more packs */
1042        return -1;
1043}
1044
1045/*
1046 * Check whether we want the object in the pack (e.g., we do not want
1047 * objects found in non-local stores if the "--local" option was used).
1048 *
1049 * If the caller already knows an existing pack it wants to take the object
1050 * from, that is passed in *found_pack and *found_offset; otherwise this
1051 * function finds if there is any pack that has the object and returns the pack
1052 * and its offset in these variables.
1053 */
1054static int want_object_in_pack(const struct object_id *oid,
1055                               int exclude,
1056                               struct packed_git **found_pack,
1057                               off_t *found_offset)
1058{
1059        int want;
1060        struct list_head *pos;
1061        struct multi_pack_index *m;
1062
1063        if (!exclude && local && has_loose_object_nonlocal(oid))
1064                return 0;
1065
1066        /*
1067         * If we already know the pack object lives in, start checks from that
1068         * pack - in the usual case when neither --local was given nor .keep files
1069         * are present we will determine the answer right now.
1070         */
1071        if (*found_pack) {
1072                want = want_found_object(exclude, *found_pack);
1073                if (want != -1)
1074                        return want;
1075        }
1076
1077        for (m = get_multi_pack_index(the_repository); m; m = m->next) {
1078                struct pack_entry e;
1079                if (fill_midx_entry(oid, &e, m)) {
1080                        struct packed_git *p = e.p;
1081                        off_t offset;
1082
1083                        if (p == *found_pack)
1084                                offset = *found_offset;
1085                        else
1086                                offset = find_pack_entry_one(oid->hash, p);
1087
1088                        if (offset) {
1089                                if (!*found_pack) {
1090                                        if (!is_pack_valid(p))
1091                                                continue;
1092                                        *found_offset = offset;
1093                                        *found_pack = p;
1094                                }
1095                                want = want_found_object(exclude, p);
1096                                if (want != -1)
1097                                        return want;
1098                        }
1099                }
1100        }
1101
1102        list_for_each(pos, get_packed_git_mru(the_repository)) {
1103                struct packed_git *p = list_entry(pos, struct packed_git, mru);
1104                off_t offset;
1105
1106                if (p == *found_pack)
1107                        offset = *found_offset;
1108                else
1109                        offset = find_pack_entry_one(oid->hash, p);
1110
1111                if (offset) {
1112                        if (!*found_pack) {
1113                                if (!is_pack_valid(p))
1114                                        continue;
1115                                *found_offset = offset;
1116                                *found_pack = p;
1117                        }
1118                        want = want_found_object(exclude, p);
1119                        if (!exclude && want > 0)
1120                                list_move(&p->mru,
1121                                          get_packed_git_mru(the_repository));
1122                        if (want != -1)
1123                                return want;
1124                }
1125        }
1126
1127        return 1;
1128}
1129
1130static void create_object_entry(const struct object_id *oid,
1131                                enum object_type type,
1132                                uint32_t hash,
1133                                int exclude,
1134                                int no_try_delta,
1135                                uint32_t index_pos,
1136                                struct packed_git *found_pack,
1137                                off_t found_offset)
1138{
1139        struct object_entry *entry;
1140
1141        entry = packlist_alloc(&to_pack, oid->hash, index_pos);
1142        entry->hash = hash;
1143        oe_set_type(entry, type);
1144        if (exclude)
1145                entry->preferred_base = 1;
1146        else
1147                nr_result++;
1148        if (found_pack) {
1149                oe_set_in_pack(&to_pack, entry, found_pack);
1150                entry->in_pack_offset = found_offset;
1151        }
1152
1153        entry->no_try_delta = no_try_delta;
1154}
1155
1156static const char no_closure_warning[] = N_(
1157"disabling bitmap writing, as some objects are not being packed"
1158);
1159
1160static int add_object_entry(const struct object_id *oid, enum object_type type,
1161                            const char *name, int exclude)
1162{
1163        struct packed_git *found_pack = NULL;
1164        off_t found_offset = 0;
1165        uint32_t index_pos;
1166
1167        display_progress(progress_state, ++nr_seen);
1168
1169        if (have_duplicate_entry(oid, exclude, &index_pos))
1170                return 0;
1171
1172        if (!want_object_in_pack(oid, exclude, &found_pack, &found_offset)) {
1173                /* The pack is missing an object, so it will not have closure */
1174                if (write_bitmap_index) {
1175                        warning(_(no_closure_warning));
1176                        write_bitmap_index = 0;
1177                }
1178                return 0;
1179        }
1180
1181        create_object_entry(oid, type, pack_name_hash(name),
1182                            exclude, name && no_try_delta(name),
1183                            index_pos, found_pack, found_offset);
1184        return 1;
1185}
1186
1187static int add_object_entry_from_bitmap(const struct object_id *oid,
1188                                        enum object_type type,
1189                                        int flags, uint32_t name_hash,
1190                                        struct packed_git *pack, off_t offset)
1191{
1192        uint32_t index_pos;
1193
1194        display_progress(progress_state, ++nr_seen);
1195
1196        if (have_duplicate_entry(oid, 0, &index_pos))
1197                return 0;
1198
1199        if (!want_object_in_pack(oid, 0, &pack, &offset))
1200                return 0;
1201
1202        create_object_entry(oid, type, name_hash, 0, 0, index_pos, pack, offset);
1203        return 1;
1204}
1205
1206struct pbase_tree_cache {
1207        struct object_id oid;
1208        int ref;
1209        int temporary;
1210        void *tree_data;
1211        unsigned long tree_size;
1212};
1213
1214static struct pbase_tree_cache *(pbase_tree_cache[256]);
1215static int pbase_tree_cache_ix(const struct object_id *oid)
1216{
1217        return oid->hash[0] % ARRAY_SIZE(pbase_tree_cache);
1218}
1219static int pbase_tree_cache_ix_incr(int ix)
1220{
1221        return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
1222}
1223
1224static struct pbase_tree {
1225        struct pbase_tree *next;
1226        /* This is a phony "cache" entry; we are not
1227         * going to evict it or find it through _get()
1228         * mechanism -- this is for the toplevel node that
1229         * would almost always change with any commit.
1230         */
1231        struct pbase_tree_cache pcache;
1232} *pbase_tree;
1233
1234static struct pbase_tree_cache *pbase_tree_get(const struct object_id *oid)
1235{
1236        struct pbase_tree_cache *ent, *nent;
1237        void *data;
1238        unsigned long size;
1239        enum object_type type;
1240        int neigh;
1241        int my_ix = pbase_tree_cache_ix(oid);
1242        int available_ix = -1;
1243
1244        /* pbase-tree-cache acts as a limited hashtable.
1245         * your object will be found at your index or within a few
1246         * slots after that slot if it is cached.
1247         */
1248        for (neigh = 0; neigh < 8; neigh++) {
1249                ent = pbase_tree_cache[my_ix];
1250                if (ent && oideq(&ent->oid, oid)) {
1251                        ent->ref++;
1252                        return ent;
1253                }
1254                else if (((available_ix < 0) && (!ent || !ent->ref)) ||
1255                         ((0 <= available_ix) &&
1256                          (!ent && pbase_tree_cache[available_ix])))
1257                        available_ix = my_ix;
1258                if (!ent)
1259                        break;
1260                my_ix = pbase_tree_cache_ix_incr(my_ix);
1261        }
1262
1263        /* Did not find one.  Either we got a bogus request or
1264         * we need to read and perhaps cache.
1265         */
1266        data = read_object_file(oid, &type, &size);
1267        if (!data)
1268                return NULL;
1269        if (type != OBJ_TREE) {
1270                free(data);
1271                return NULL;
1272        }
1273
1274        /* We need to either cache or return a throwaway copy */
1275
1276        if (available_ix < 0)
1277                ent = NULL;
1278        else {
1279                ent = pbase_tree_cache[available_ix];
1280                my_ix = available_ix;
1281        }
1282
1283        if (!ent) {
1284                nent = xmalloc(sizeof(*nent));
1285                nent->temporary = (available_ix < 0);
1286        }
1287        else {
1288                /* evict and reuse */
1289                free(ent->tree_data);
1290                nent = ent;
1291        }
1292        oidcpy(&nent->oid, oid);
1293        nent->tree_data = data;
1294        nent->tree_size = size;
1295        nent->ref = 1;
1296        if (!nent->temporary)
1297                pbase_tree_cache[my_ix] = nent;
1298        return nent;
1299}
1300
1301static void pbase_tree_put(struct pbase_tree_cache *cache)
1302{
1303        if (!cache->temporary) {
1304                cache->ref--;
1305                return;
1306        }
1307        free(cache->tree_data);
1308        free(cache);
1309}
1310
1311static int name_cmp_len(const char *name)
1312{
1313        int i;
1314        for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
1315                ;
1316        return i;
1317}
1318
1319static void add_pbase_object(struct tree_desc *tree,
1320                             const char *name,
1321                             int cmplen,
1322                             const char *fullname)
1323{
1324        struct name_entry entry;
1325        int cmp;
1326
1327        while (tree_entry(tree,&entry)) {
1328                if (S_ISGITLINK(entry.mode))
1329                        continue;
1330                cmp = tree_entry_len(&entry) != cmplen ? 1 :
1331                      memcmp(name, entry.path, cmplen);
1332                if (cmp > 0)
1333                        continue;
1334                if (cmp < 0)
1335                        return;
1336                if (name[cmplen] != '/') {
1337                        add_object_entry(entry.oid,
1338                                         object_type(entry.mode),
1339                                         fullname, 1);
1340                        return;
1341                }
1342                if (S_ISDIR(entry.mode)) {
1343                        struct tree_desc sub;
1344                        struct pbase_tree_cache *tree;
1345                        const char *down = name+cmplen+1;
1346                        int downlen = name_cmp_len(down);
1347
1348                        tree = pbase_tree_get(entry.oid);
1349                        if (!tree)
1350                                return;
1351                        init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1352
1353                        add_pbase_object(&sub, down, downlen, fullname);
1354                        pbase_tree_put(tree);
1355                }
1356        }
1357}
1358
1359static unsigned *done_pbase_paths;
1360static int done_pbase_paths_num;
1361static int done_pbase_paths_alloc;
1362static int done_pbase_path_pos(unsigned hash)
1363{
1364        int lo = 0;
1365        int hi = done_pbase_paths_num;
1366        while (lo < hi) {
1367                int mi = lo + (hi - lo) / 2;
1368                if (done_pbase_paths[mi] == hash)
1369                        return mi;
1370                if (done_pbase_paths[mi] < hash)
1371                        hi = mi;
1372                else
1373                        lo = mi + 1;
1374        }
1375        return -lo-1;
1376}
1377
1378static int check_pbase_path(unsigned hash)
1379{
1380        int pos = done_pbase_path_pos(hash);
1381        if (0 <= pos)
1382                return 1;
1383        pos = -pos - 1;
1384        ALLOC_GROW(done_pbase_paths,
1385                   done_pbase_paths_num + 1,
1386                   done_pbase_paths_alloc);
1387        done_pbase_paths_num++;
1388        if (pos < done_pbase_paths_num)
1389                MOVE_ARRAY(done_pbase_paths + pos + 1, done_pbase_paths + pos,
1390                           done_pbase_paths_num - pos - 1);
1391        done_pbase_paths[pos] = hash;
1392        return 0;
1393}
1394
1395static void add_preferred_base_object(const char *name)
1396{
1397        struct pbase_tree *it;
1398        int cmplen;
1399        unsigned hash = pack_name_hash(name);
1400
1401        if (!num_preferred_base || check_pbase_path(hash))
1402                return;
1403
1404        cmplen = name_cmp_len(name);
1405        for (it = pbase_tree; it; it = it->next) {
1406                if (cmplen == 0) {
1407                        add_object_entry(&it->pcache.oid, OBJ_TREE, NULL, 1);
1408                }
1409                else {
1410                        struct tree_desc tree;
1411                        init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1412                        add_pbase_object(&tree, name, cmplen, name);
1413                }
1414        }
1415}
1416
1417static void add_preferred_base(struct object_id *oid)
1418{
1419        struct pbase_tree *it;
1420        void *data;
1421        unsigned long size;
1422        struct object_id tree_oid;
1423
1424        if (window <= num_preferred_base++)
1425                return;
1426
1427        data = read_object_with_reference(oid, tree_type, &size, &tree_oid);
1428        if (!data)
1429                return;
1430
1431        for (it = pbase_tree; it; it = it->next) {
1432                if (oideq(&it->pcache.oid, &tree_oid)) {
1433                        free(data);
1434                        return;
1435                }
1436        }
1437
1438        it = xcalloc(1, sizeof(*it));
1439        it->next = pbase_tree;
1440        pbase_tree = it;
1441
1442        oidcpy(&it->pcache.oid, &tree_oid);
1443        it->pcache.tree_data = data;
1444        it->pcache.tree_size = size;
1445}
1446
1447static void cleanup_preferred_base(void)
1448{
1449        struct pbase_tree *it;
1450        unsigned i;
1451
1452        it = pbase_tree;
1453        pbase_tree = NULL;
1454        while (it) {
1455                struct pbase_tree *tmp = it;
1456                it = tmp->next;
1457                free(tmp->pcache.tree_data);
1458                free(tmp);
1459        }
1460
1461        for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1462                if (!pbase_tree_cache[i])
1463                        continue;
1464                free(pbase_tree_cache[i]->tree_data);
1465                FREE_AND_NULL(pbase_tree_cache[i]);
1466        }
1467
1468        FREE_AND_NULL(done_pbase_paths);
1469        done_pbase_paths_num = done_pbase_paths_alloc = 0;
1470}
1471
1472/*
1473 * Return 1 iff the object specified by "delta" can be sent
1474 * literally as a delta against the base in "base_sha1". If
1475 * so, then *base_out will point to the entry in our packing
1476 * list, or NULL if we must use the external-base list.
1477 *
1478 * Depth value does not matter - find_deltas() will
1479 * never consider reused delta as the base object to
1480 * deltify other objects against, in order to avoid
1481 * circular deltas.
1482 */
1483static int can_reuse_delta(const unsigned char *base_sha1,
1484                           struct object_entry *delta,
1485                           struct object_entry **base_out)
1486{
1487        struct object_entry *base;
1488
1489        if (!base_sha1)
1490                return 0;
1491
1492        /*
1493         * First see if we're already sending the base (or it's explicitly in
1494         * our "excluded" list).
1495         */
1496        base = packlist_find(&to_pack, base_sha1, NULL);
1497        if (base) {
1498                if (!in_same_island(&delta->idx.oid, &base->idx.oid))
1499                        return 0;
1500                *base_out = base;
1501                return 1;
1502        }
1503
1504        /*
1505         * Otherwise, reachability bitmaps may tell us if the receiver has it,
1506         * even if it was buried too deep in history to make it into the
1507         * packing list.
1508         */
1509        if (thin && bitmap_has_sha1_in_uninteresting(bitmap_git, base_sha1)) {
1510                if (use_delta_islands) {
1511                        struct object_id base_oid;
1512                        hashcpy(base_oid.hash, base_sha1);
1513                        if (!in_same_island(&delta->idx.oid, &base_oid))
1514                                return 0;
1515                }
1516                *base_out = NULL;
1517                return 1;
1518        }
1519
1520        return 0;
1521}
1522
1523static void check_object(struct object_entry *entry)
1524{
1525        unsigned long canonical_size;
1526
1527        if (IN_PACK(entry)) {
1528                struct packed_git *p = IN_PACK(entry);
1529                struct pack_window *w_curs = NULL;
1530                const unsigned char *base_ref = NULL;
1531                struct object_entry *base_entry;
1532                unsigned long used, used_0;
1533                unsigned long avail;
1534                off_t ofs;
1535                unsigned char *buf, c;
1536                enum object_type type;
1537                unsigned long in_pack_size;
1538
1539                buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1540
1541                /*
1542                 * We want in_pack_type even if we do not reuse delta
1543                 * since non-delta representations could still be reused.
1544                 */
1545                used = unpack_object_header_buffer(buf, avail,
1546                                                   &type,
1547                                                   &in_pack_size);
1548                if (used == 0)
1549                        goto give_up;
1550
1551                if (type < 0)
1552                        BUG("invalid type %d", type);
1553                entry->in_pack_type = type;
1554
1555                /*
1556                 * Determine if this is a delta and if so whether we can
1557                 * reuse it or not.  Otherwise let's find out as cheaply as
1558                 * possible what the actual type and size for this object is.
1559                 */
1560                switch (entry->in_pack_type) {
1561                default:
1562                        /* Not a delta hence we've already got all we need. */
1563                        oe_set_type(entry, entry->in_pack_type);
1564                        SET_SIZE(entry, in_pack_size);
1565                        entry->in_pack_header_size = used;
1566                        if (oe_type(entry) < OBJ_COMMIT || oe_type(entry) > OBJ_BLOB)
1567                                goto give_up;
1568                        unuse_pack(&w_curs);
1569                        return;
1570                case OBJ_REF_DELTA:
1571                        if (reuse_delta && !entry->preferred_base)
1572                                base_ref = use_pack(p, &w_curs,
1573                                                entry->in_pack_offset + used, NULL);
1574                        entry->in_pack_header_size = used + the_hash_algo->rawsz;
1575                        break;
1576                case OBJ_OFS_DELTA:
1577                        buf = use_pack(p, &w_curs,
1578                                       entry->in_pack_offset + used, NULL);
1579                        used_0 = 0;
1580                        c = buf[used_0++];
1581                        ofs = c & 127;
1582                        while (c & 128) {
1583                                ofs += 1;
1584                                if (!ofs || MSB(ofs, 7)) {
1585                                        error(_("delta base offset overflow in pack for %s"),
1586                                              oid_to_hex(&entry->idx.oid));
1587                                        goto give_up;
1588                                }
1589                                c = buf[used_0++];
1590                                ofs = (ofs << 7) + (c & 127);
1591                        }
1592                        ofs = entry->in_pack_offset - ofs;
1593                        if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1594                                error(_("delta base offset out of bound for %s"),
1595                                      oid_to_hex(&entry->idx.oid));
1596                                goto give_up;
1597                        }
1598                        if (reuse_delta && !entry->preferred_base) {
1599                                struct revindex_entry *revidx;
1600                                revidx = find_pack_revindex(p, ofs);
1601                                if (!revidx)
1602                                        goto give_up;
1603                                base_ref = nth_packed_object_sha1(p, revidx->nr);
1604                        }
1605                        entry->in_pack_header_size = used + used_0;
1606                        break;
1607                }
1608
1609                if (can_reuse_delta(base_ref, entry, &base_entry)) {
1610                        oe_set_type(entry, entry->in_pack_type);
1611                        SET_SIZE(entry, in_pack_size); /* delta size */
1612                        SET_DELTA_SIZE(entry, in_pack_size);
1613
1614                        if (base_entry) {
1615                                SET_DELTA(entry, base_entry);
1616                                entry->delta_sibling_idx = base_entry->delta_child_idx;
1617                                SET_DELTA_CHILD(base_entry, entry);
1618                        } else {
1619                                SET_DELTA_EXT(entry, base_ref);
1620                        }
1621
1622                        unuse_pack(&w_curs);
1623                        return;
1624                }
1625
1626                if (oe_type(entry)) {
1627                        off_t delta_pos;
1628
1629                        /*
1630                         * This must be a delta and we already know what the
1631                         * final object type is.  Let's extract the actual
1632                         * object size from the delta header.
1633                         */
1634                        delta_pos = entry->in_pack_offset + entry->in_pack_header_size;
1635                        canonical_size = get_size_from_delta(p, &w_curs, delta_pos);
1636                        if (canonical_size == 0)
1637                                goto give_up;
1638                        SET_SIZE(entry, canonical_size);
1639                        unuse_pack(&w_curs);
1640                        return;
1641                }
1642
1643                /*
1644                 * No choice but to fall back to the recursive delta walk
1645                 * with sha1_object_info() to find about the object type
1646                 * at this point...
1647                 */
1648                give_up:
1649                unuse_pack(&w_curs);
1650        }
1651
1652        oe_set_type(entry,
1653                    oid_object_info(the_repository, &entry->idx.oid, &canonical_size));
1654        if (entry->type_valid) {
1655                SET_SIZE(entry, canonical_size);
1656        } else {
1657                /*
1658                 * Bad object type is checked in prepare_pack().  This is
1659                 * to permit a missing preferred base object to be ignored
1660                 * as a preferred base.  Doing so can result in a larger
1661                 * pack file, but the transfer will still take place.
1662                 */
1663        }
1664}
1665
1666static int pack_offset_sort(const void *_a, const void *_b)
1667{
1668        const struct object_entry *a = *(struct object_entry **)_a;
1669        const struct object_entry *b = *(struct object_entry **)_b;
1670        const struct packed_git *a_in_pack = IN_PACK(a);
1671        const struct packed_git *b_in_pack = IN_PACK(b);
1672
1673        /* avoid filesystem trashing with loose objects */
1674        if (!a_in_pack && !b_in_pack)
1675                return oidcmp(&a->idx.oid, &b->idx.oid);
1676
1677        if (a_in_pack < b_in_pack)
1678                return -1;
1679        if (a_in_pack > b_in_pack)
1680                return 1;
1681        return a->in_pack_offset < b->in_pack_offset ? -1 :
1682                        (a->in_pack_offset > b->in_pack_offset);
1683}
1684
1685/*
1686 * Drop an on-disk delta we were planning to reuse. Naively, this would
1687 * just involve blanking out the "delta" field, but we have to deal
1688 * with some extra book-keeping:
1689 *
1690 *   1. Removing ourselves from the delta_sibling linked list.
1691 *
1692 *   2. Updating our size/type to the non-delta representation. These were
1693 *      either not recorded initially (size) or overwritten with the delta type
1694 *      (type) when check_object() decided to reuse the delta.
1695 *
1696 *   3. Resetting our delta depth, as we are now a base object.
1697 */
1698static void drop_reused_delta(struct object_entry *entry)
1699{
1700        unsigned *idx = &to_pack.objects[entry->delta_idx - 1].delta_child_idx;
1701        struct object_info oi = OBJECT_INFO_INIT;
1702        enum object_type type;
1703        unsigned long size;
1704
1705        while (*idx) {
1706                struct object_entry *oe = &to_pack.objects[*idx - 1];
1707
1708                if (oe == entry)
1709                        *idx = oe->delta_sibling_idx;
1710                else
1711                        idx = &oe->delta_sibling_idx;
1712        }
1713        SET_DELTA(entry, NULL);
1714        entry->depth = 0;
1715
1716        oi.sizep = &size;
1717        oi.typep = &type;
1718        if (packed_object_info(the_repository, IN_PACK(entry), entry->in_pack_offset, &oi) < 0) {
1719                /*
1720                 * We failed to get the info from this pack for some reason;
1721                 * fall back to sha1_object_info, which may find another copy.
1722                 * And if that fails, the error will be recorded in oe_type(entry)
1723                 * and dealt with in prepare_pack().
1724                 */
1725                oe_set_type(entry,
1726                            oid_object_info(the_repository, &entry->idx.oid, &size));
1727        } else {
1728                oe_set_type(entry, type);
1729        }
1730        SET_SIZE(entry, size);
1731}
1732
1733/*
1734 * Follow the chain of deltas from this entry onward, throwing away any links
1735 * that cause us to hit a cycle (as determined by the DFS state flags in
1736 * the entries).
1737 *
1738 * We also detect too-long reused chains that would violate our --depth
1739 * limit.
1740 */
1741static void break_delta_chains(struct object_entry *entry)
1742{
1743        /*
1744         * The actual depth of each object we will write is stored as an int,
1745         * as it cannot exceed our int "depth" limit. But before we break
1746         * changes based no that limit, we may potentially go as deep as the
1747         * number of objects, which is elsewhere bounded to a uint32_t.
1748         */
1749        uint32_t total_depth;
1750        struct object_entry *cur, *next;
1751
1752        for (cur = entry, total_depth = 0;
1753             cur;
1754             cur = DELTA(cur), total_depth++) {
1755                if (cur->dfs_state == DFS_DONE) {
1756                        /*
1757                         * We've already seen this object and know it isn't
1758                         * part of a cycle. We do need to append its depth
1759                         * to our count.
1760                         */
1761                        total_depth += cur->depth;
1762                        break;
1763                }
1764
1765                /*
1766                 * We break cycles before looping, so an ACTIVE state (or any
1767                 * other cruft which made its way into the state variable)
1768                 * is a bug.
1769                 */
1770                if (cur->dfs_state != DFS_NONE)
1771                        BUG("confusing delta dfs state in first pass: %d",
1772                            cur->dfs_state);
1773
1774                /*
1775                 * Now we know this is the first time we've seen the object. If
1776                 * it's not a delta, we're done traversing, but we'll mark it
1777                 * done to save time on future traversals.
1778                 */
1779                if (!DELTA(cur)) {
1780                        cur->dfs_state = DFS_DONE;
1781                        break;
1782                }
1783
1784                /*
1785                 * Mark ourselves as active and see if the next step causes
1786                 * us to cycle to another active object. It's important to do
1787                 * this _before_ we loop, because it impacts where we make the
1788                 * cut, and thus how our total_depth counter works.
1789                 * E.g., We may see a partial loop like:
1790                 *
1791                 *   A -> B -> C -> D -> B
1792                 *
1793                 * Cutting B->C breaks the cycle. But now the depth of A is
1794                 * only 1, and our total_depth counter is at 3. The size of the
1795                 * error is always one less than the size of the cycle we
1796                 * broke. Commits C and D were "lost" from A's chain.
1797                 *
1798                 * If we instead cut D->B, then the depth of A is correct at 3.
1799                 * We keep all commits in the chain that we examined.
1800                 */
1801                cur->dfs_state = DFS_ACTIVE;
1802                if (DELTA(cur)->dfs_state == DFS_ACTIVE) {
1803                        drop_reused_delta(cur);
1804                        cur->dfs_state = DFS_DONE;
1805                        break;
1806                }
1807        }
1808
1809        /*
1810         * And now that we've gone all the way to the bottom of the chain, we
1811         * need to clear the active flags and set the depth fields as
1812         * appropriate. Unlike the loop above, which can quit when it drops a
1813         * delta, we need to keep going to look for more depth cuts. So we need
1814         * an extra "next" pointer to keep going after we reset cur->delta.
1815         */
1816        for (cur = entry; cur; cur = next) {
1817                next = DELTA(cur);
1818
1819                /*
1820                 * We should have a chain of zero or more ACTIVE states down to
1821                 * a final DONE. We can quit after the DONE, because either it
1822                 * has no bases, or we've already handled them in a previous
1823                 * call.
1824                 */
1825                if (cur->dfs_state == DFS_DONE)
1826                        break;
1827                else if (cur->dfs_state != DFS_ACTIVE)
1828                        BUG("confusing delta dfs state in second pass: %d",
1829                            cur->dfs_state);
1830
1831                /*
1832                 * If the total_depth is more than depth, then we need to snip
1833                 * the chain into two or more smaller chains that don't exceed
1834                 * the maximum depth. Most of the resulting chains will contain
1835                 * (depth + 1) entries (i.e., depth deltas plus one base), and
1836                 * the last chain (i.e., the one containing entry) will contain
1837                 * whatever entries are left over, namely
1838                 * (total_depth % (depth + 1)) of them.
1839                 *
1840                 * Since we are iterating towards decreasing depth, we need to
1841                 * decrement total_depth as we go, and we need to write to the
1842                 * entry what its final depth will be after all of the
1843                 * snipping. Since we're snipping into chains of length (depth
1844                 * + 1) entries, the final depth of an entry will be its
1845                 * original depth modulo (depth + 1). Any time we encounter an
1846                 * entry whose final depth is supposed to be zero, we snip it
1847                 * from its delta base, thereby making it so.
1848                 */
1849                cur->depth = (total_depth--) % (depth + 1);
1850                if (!cur->depth)
1851                        drop_reused_delta(cur);
1852
1853                cur->dfs_state = DFS_DONE;
1854        }
1855}
1856
1857static void get_object_details(void)
1858{
1859        uint32_t i;
1860        struct object_entry **sorted_by_offset;
1861
1862        if (progress)
1863                progress_state = start_progress(_("Counting objects"),
1864                                                to_pack.nr_objects);
1865
1866        sorted_by_offset = xcalloc(to_pack.nr_objects, sizeof(struct object_entry *));
1867        for (i = 0; i < to_pack.nr_objects; i++)
1868                sorted_by_offset[i] = to_pack.objects + i;
1869        QSORT(sorted_by_offset, to_pack.nr_objects, pack_offset_sort);
1870
1871        for (i = 0; i < to_pack.nr_objects; i++) {
1872                struct object_entry *entry = sorted_by_offset[i];
1873                check_object(entry);
1874                if (entry->type_valid &&
1875                    oe_size_greater_than(&to_pack, entry, big_file_threshold))
1876                        entry->no_try_delta = 1;
1877                display_progress(progress_state, i + 1);
1878        }
1879        stop_progress(&progress_state);
1880
1881        /*
1882         * This must happen in a second pass, since we rely on the delta
1883         * information for the whole list being completed.
1884         */
1885        for (i = 0; i < to_pack.nr_objects; i++)
1886                break_delta_chains(&to_pack.objects[i]);
1887
1888        free(sorted_by_offset);
1889}
1890
1891/*
1892 * We search for deltas in a list sorted by type, by filename hash, and then
1893 * by size, so that we see progressively smaller and smaller files.
1894 * That's because we prefer deltas to be from the bigger file
1895 * to the smaller -- deletes are potentially cheaper, but perhaps
1896 * more importantly, the bigger file is likely the more recent
1897 * one.  The deepest deltas are therefore the oldest objects which are
1898 * less susceptible to be accessed often.
1899 */
1900static int type_size_sort(const void *_a, const void *_b)
1901{
1902        const struct object_entry *a = *(struct object_entry **)_a;
1903        const struct object_entry *b = *(struct object_entry **)_b;
1904        enum object_type a_type = oe_type(a);
1905        enum object_type b_type = oe_type(b);
1906        unsigned long a_size = SIZE(a);
1907        unsigned long b_size = SIZE(b);
1908
1909        if (a_type > b_type)
1910                return -1;
1911        if (a_type < b_type)
1912                return 1;
1913        if (a->hash > b->hash)
1914                return -1;
1915        if (a->hash < b->hash)
1916                return 1;
1917        if (a->preferred_base > b->preferred_base)
1918                return -1;
1919        if (a->preferred_base < b->preferred_base)
1920                return 1;
1921        if (use_delta_islands) {
1922                int island_cmp = island_delta_cmp(&a->idx.oid, &b->idx.oid);
1923                if (island_cmp)
1924                        return island_cmp;
1925        }
1926        if (a_size > b_size)
1927                return -1;
1928        if (a_size < b_size)
1929                return 1;
1930        return a < b ? -1 : (a > b);  /* newest first */
1931}
1932
1933struct unpacked {
1934        struct object_entry *entry;
1935        void *data;
1936        struct delta_index *index;
1937        unsigned depth;
1938};
1939
1940static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1941                           unsigned long delta_size)
1942{
1943        if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1944                return 0;
1945
1946        if (delta_size < cache_max_small_delta_size)
1947                return 1;
1948
1949        /* cache delta, if objects are large enough compared to delta size */
1950        if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1951                return 1;
1952
1953        return 0;
1954}
1955
1956/* Protect access to object database */
1957static pthread_mutex_t read_mutex;
1958#define read_lock()             pthread_mutex_lock(&read_mutex)
1959#define read_unlock()           pthread_mutex_unlock(&read_mutex)
1960
1961/* Protect delta_cache_size */
1962static pthread_mutex_t cache_mutex;
1963#define cache_lock()            pthread_mutex_lock(&cache_mutex)
1964#define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1965
1966/*
1967 * Protect object list partitioning (e.g. struct thread_param) and
1968 * progress_state
1969 */
1970static pthread_mutex_t progress_mutex;
1971#define progress_lock()         pthread_mutex_lock(&progress_mutex)
1972#define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1973
1974/*
1975 * Access to struct object_entry is unprotected since each thread owns
1976 * a portion of the main object list. Just don't access object entries
1977 * ahead in the list because they can be stolen and would need
1978 * progress_mutex for protection.
1979 */
1980
1981/*
1982 * Return the size of the object without doing any delta
1983 * reconstruction (so non-deltas are true object sizes, but deltas
1984 * return the size of the delta data).
1985 */
1986unsigned long oe_get_size_slow(struct packing_data *pack,
1987                               const struct object_entry *e)
1988{
1989        struct packed_git *p;
1990        struct pack_window *w_curs;
1991        unsigned char *buf;
1992        enum object_type type;
1993        unsigned long used, avail, size;
1994
1995        if (e->type_ != OBJ_OFS_DELTA && e->type_ != OBJ_REF_DELTA) {
1996                read_lock();
1997                if (oid_object_info(the_repository, &e->idx.oid, &size) < 0)
1998                        die(_("unable to get size of %s"),
1999                            oid_to_hex(&e->idx.oid));
2000                read_unlock();
2001                return size;
2002        }
2003
2004        p = oe_in_pack(pack, e);
2005        if (!p)
2006                BUG("when e->type is a delta, it must belong to a pack");
2007
2008        read_lock();
2009        w_curs = NULL;
2010        buf = use_pack(p, &w_curs, e->in_pack_offset, &avail);
2011        used = unpack_object_header_buffer(buf, avail, &type, &size);
2012        if (used == 0)
2013                die(_("unable to parse object header of %s"),
2014                    oid_to_hex(&e->idx.oid));
2015
2016        unuse_pack(&w_curs);
2017        read_unlock();
2018        return size;
2019}
2020
2021static int try_delta(struct unpacked *trg, struct unpacked *src,
2022                     unsigned max_depth, unsigned long *mem_usage)
2023{
2024        struct object_entry *trg_entry = trg->entry;
2025        struct object_entry *src_entry = src->entry;
2026        unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
2027        unsigned ref_depth;
2028        enum object_type type;
2029        void *delta_buf;
2030
2031        /* Don't bother doing diffs between different types */
2032        if (oe_type(trg_entry) != oe_type(src_entry))
2033                return -1;
2034
2035        /*
2036         * We do not bother to try a delta that we discarded on an
2037         * earlier try, but only when reusing delta data.  Note that
2038         * src_entry that is marked as the preferred_base should always
2039         * be considered, as even if we produce a suboptimal delta against
2040         * it, we will still save the transfer cost, as we already know
2041         * the other side has it and we won't send src_entry at all.
2042         */
2043        if (reuse_delta && IN_PACK(trg_entry) &&
2044            IN_PACK(trg_entry) == IN_PACK(src_entry) &&
2045            !src_entry->preferred_base &&
2046            trg_entry->in_pack_type != OBJ_REF_DELTA &&
2047            trg_entry->in_pack_type != OBJ_OFS_DELTA)
2048                return 0;
2049
2050        /* Let's not bust the allowed depth. */
2051        if (src->depth >= max_depth)
2052                return 0;
2053
2054        /* Now some size filtering heuristics. */
2055        trg_size = SIZE(trg_entry);
2056        if (!DELTA(trg_entry)) {
2057                max_size = trg_size/2 - the_hash_algo->rawsz;
2058                ref_depth = 1;
2059        } else {
2060                max_size = DELTA_SIZE(trg_entry);
2061                ref_depth = trg->depth;
2062        }
2063        max_size = (uint64_t)max_size * (max_depth - src->depth) /
2064                                                (max_depth - ref_depth + 1);
2065        if (max_size == 0)
2066                return 0;
2067        src_size = SIZE(src_entry);
2068        sizediff = src_size < trg_size ? trg_size - src_size : 0;
2069        if (sizediff >= max_size)
2070                return 0;
2071        if (trg_size < src_size / 32)
2072                return 0;
2073
2074        if (!in_same_island(&trg->entry->idx.oid, &src->entry->idx.oid))
2075                return 0;
2076
2077        /* Load data if not already done */
2078        if (!trg->data) {
2079                read_lock();
2080                trg->data = read_object_file(&trg_entry->idx.oid, &type, &sz);
2081                read_unlock();
2082                if (!trg->data)
2083                        die(_("object %s cannot be read"),
2084                            oid_to_hex(&trg_entry->idx.oid));
2085                if (sz != trg_size)
2086                        die(_("object %s inconsistent object length (%"PRIuMAX" vs %"PRIuMAX")"),
2087                            oid_to_hex(&trg_entry->idx.oid), (uintmax_t)sz,
2088                            (uintmax_t)trg_size);
2089                *mem_usage += sz;
2090        }
2091        if (!src->data) {
2092                read_lock();
2093                src->data = read_object_file(&src_entry->idx.oid, &type, &sz);
2094                read_unlock();
2095                if (!src->data) {
2096                        if (src_entry->preferred_base) {
2097                                static int warned = 0;
2098                                if (!warned++)
2099                                        warning(_("object %s cannot be read"),
2100                                                oid_to_hex(&src_entry->idx.oid));
2101                                /*
2102                                 * Those objects are not included in the
2103                                 * resulting pack.  Be resilient and ignore
2104                                 * them if they can't be read, in case the
2105                                 * pack could be created nevertheless.
2106                                 */
2107                                return 0;
2108                        }
2109                        die(_("object %s cannot be read"),
2110                            oid_to_hex(&src_entry->idx.oid));
2111                }
2112                if (sz != src_size)
2113                        die(_("object %s inconsistent object length (%"PRIuMAX" vs %"PRIuMAX")"),
2114                            oid_to_hex(&src_entry->idx.oid), (uintmax_t)sz,
2115                            (uintmax_t)src_size);
2116                *mem_usage += sz;
2117        }
2118        if (!src->index) {
2119                src->index = create_delta_index(src->data, src_size);
2120                if (!src->index) {
2121                        static int warned = 0;
2122                        if (!warned++)
2123                                warning(_("suboptimal pack - out of memory"));
2124                        return 0;
2125                }
2126                *mem_usage += sizeof_delta_index(src->index);
2127        }
2128
2129        delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
2130        if (!delta_buf)
2131                return 0;
2132
2133        if (DELTA(trg_entry)) {
2134                /* Prefer only shallower same-sized deltas. */
2135                if (delta_size == DELTA_SIZE(trg_entry) &&
2136                    src->depth + 1 >= trg->depth) {
2137                        free(delta_buf);
2138                        return 0;
2139                }
2140        }
2141
2142        /*
2143         * Handle memory allocation outside of the cache
2144         * accounting lock.  Compiler will optimize the strangeness
2145         * away when NO_PTHREADS is defined.
2146         */
2147        free(trg_entry->delta_data);
2148        cache_lock();
2149        if (trg_entry->delta_data) {
2150                delta_cache_size -= DELTA_SIZE(trg_entry);
2151                trg_entry->delta_data = NULL;
2152        }
2153        if (delta_cacheable(src_size, trg_size, delta_size)) {
2154                delta_cache_size += delta_size;
2155                cache_unlock();
2156                trg_entry->delta_data = xrealloc(delta_buf, delta_size);
2157        } else {
2158                cache_unlock();
2159                free(delta_buf);
2160        }
2161
2162        SET_DELTA(trg_entry, src_entry);
2163        SET_DELTA_SIZE(trg_entry, delta_size);
2164        trg->depth = src->depth + 1;
2165
2166        return 1;
2167}
2168
2169static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
2170{
2171        struct object_entry *child = DELTA_CHILD(me);
2172        unsigned int m = n;
2173        while (child) {
2174                unsigned int c = check_delta_limit(child, n + 1);
2175                if (m < c)
2176                        m = c;
2177                child = DELTA_SIBLING(child);
2178        }
2179        return m;
2180}
2181
2182static unsigned long free_unpacked(struct unpacked *n)
2183{
2184        unsigned long freed_mem = sizeof_delta_index(n->index);
2185        free_delta_index(n->index);
2186        n->index = NULL;
2187        if (n->data) {
2188                freed_mem += SIZE(n->entry);
2189                FREE_AND_NULL(n->data);
2190        }
2191        n->entry = NULL;
2192        n->depth = 0;
2193        return freed_mem;
2194}
2195
2196static void find_deltas(struct object_entry **list, unsigned *list_size,
2197                        int window, int depth, unsigned *processed)
2198{
2199        uint32_t i, idx = 0, count = 0;
2200        struct unpacked *array;
2201        unsigned long mem_usage = 0;
2202
2203        array = xcalloc(window, sizeof(struct unpacked));
2204
2205        for (;;) {
2206                struct object_entry *entry;
2207                struct unpacked *n = array + idx;
2208                int j, max_depth, best_base = -1;
2209
2210                progress_lock();
2211                if (!*list_size) {
2212                        progress_unlock();
2213                        break;
2214                }
2215                entry = *list++;
2216                (*list_size)--;
2217                if (!entry->preferred_base) {
2218                        (*processed)++;
2219                        display_progress(progress_state, *processed);
2220                }
2221                progress_unlock();
2222
2223                mem_usage -= free_unpacked(n);
2224                n->entry = entry;
2225
2226                while (window_memory_limit &&
2227                       mem_usage > window_memory_limit &&
2228                       count > 1) {
2229                        uint32_t tail = (idx + window - count) % window;
2230                        mem_usage -= free_unpacked(array + tail);
2231                        count--;
2232                }
2233
2234                /* We do not compute delta to *create* objects we are not
2235                 * going to pack.
2236                 */
2237                if (entry->preferred_base)
2238                        goto next;
2239
2240                /*
2241                 * If the current object is at pack edge, take the depth the
2242                 * objects that depend on the current object into account
2243                 * otherwise they would become too deep.
2244                 */
2245                max_depth = depth;
2246                if (DELTA_CHILD(entry)) {
2247                        max_depth -= check_delta_limit(entry, 0);
2248                        if (max_depth <= 0)
2249                                goto next;
2250                }
2251
2252                j = window;
2253                while (--j > 0) {
2254                        int ret;
2255                        uint32_t other_idx = idx + j;
2256                        struct unpacked *m;
2257                        if (other_idx >= window)
2258                                other_idx -= window;
2259                        m = array + other_idx;
2260                        if (!m->entry)
2261                                break;
2262                        ret = try_delta(n, m, max_depth, &mem_usage);
2263                        if (ret < 0)
2264                                break;
2265                        else if (ret > 0)
2266                                best_base = other_idx;
2267                }
2268
2269                /*
2270                 * If we decided to cache the delta data, then it is best
2271                 * to compress it right away.  First because we have to do
2272                 * it anyway, and doing it here while we're threaded will
2273                 * save a lot of time in the non threaded write phase,
2274                 * as well as allow for caching more deltas within
2275                 * the same cache size limit.
2276                 * ...
2277                 * But only if not writing to stdout, since in that case
2278                 * the network is most likely throttling writes anyway,
2279                 * and therefore it is best to go to the write phase ASAP
2280                 * instead, as we can afford spending more time compressing
2281                 * between writes at that moment.
2282                 */
2283                if (entry->delta_data && !pack_to_stdout) {
2284                        unsigned long size;
2285
2286                        size = do_compress(&entry->delta_data, DELTA_SIZE(entry));
2287                        if (size < (1U << OE_Z_DELTA_BITS)) {
2288                                entry->z_delta_size = size;
2289                                cache_lock();
2290                                delta_cache_size -= DELTA_SIZE(entry);
2291                                delta_cache_size += entry->z_delta_size;
2292                                cache_unlock();
2293                        } else {
2294                                FREE_AND_NULL(entry->delta_data);
2295                                entry->z_delta_size = 0;
2296                        }
2297                }
2298
2299                /* if we made n a delta, and if n is already at max
2300                 * depth, leaving it in the window is pointless.  we
2301                 * should evict it first.
2302                 */
2303                if (DELTA(entry) && max_depth <= n->depth)
2304                        continue;
2305
2306                /*
2307                 * Move the best delta base up in the window, after the
2308                 * currently deltified object, to keep it longer.  It will
2309                 * be the first base object to be attempted next.
2310                 */
2311                if (DELTA(entry)) {
2312                        struct unpacked swap = array[best_base];
2313                        int dist = (window + idx - best_base) % window;
2314                        int dst = best_base;
2315                        while (dist--) {
2316                                int src = (dst + 1) % window;
2317                                array[dst] = array[src];
2318                                dst = src;
2319                        }
2320                        array[dst] = swap;
2321                }
2322
2323                next:
2324                idx++;
2325                if (count + 1 < window)
2326                        count++;
2327                if (idx >= window)
2328                        idx = 0;
2329        }
2330
2331        for (i = 0; i < window; ++i) {
2332                free_delta_index(array[i].index);
2333                free(array[i].data);
2334        }
2335        free(array);
2336}
2337
2338static void try_to_free_from_threads(size_t size)
2339{
2340        read_lock();
2341        release_pack_memory(size);
2342        read_unlock();
2343}
2344
2345static try_to_free_t old_try_to_free_routine;
2346
2347/*
2348 * The main object list is split into smaller lists, each is handed to
2349 * one worker.
2350 *
2351 * The main thread waits on the condition that (at least) one of the workers
2352 * has stopped working (which is indicated in the .working member of
2353 * struct thread_params).
2354 *
2355 * When a work thread has completed its work, it sets .working to 0 and
2356 * signals the main thread and waits on the condition that .data_ready
2357 * becomes 1.
2358 *
2359 * The main thread steals half of the work from the worker that has
2360 * most work left to hand it to the idle worker.
2361 */
2362
2363struct thread_params {
2364        pthread_t thread;
2365        struct object_entry **list;
2366        unsigned list_size;
2367        unsigned remaining;
2368        int window;
2369        int depth;
2370        int working;
2371        int data_ready;
2372        pthread_mutex_t mutex;
2373        pthread_cond_t cond;
2374        unsigned *processed;
2375};
2376
2377static pthread_cond_t progress_cond;
2378
2379/*
2380 * Mutex and conditional variable can't be statically-initialized on Windows.
2381 */
2382static void init_threaded_search(void)
2383{
2384        init_recursive_mutex(&read_mutex);
2385        pthread_mutex_init(&cache_mutex, NULL);
2386        pthread_mutex_init(&progress_mutex, NULL);
2387        pthread_cond_init(&progress_cond, NULL);
2388        old_try_to_free_routine = set_try_to_free_routine(try_to_free_from_threads);
2389}
2390
2391static void cleanup_threaded_search(void)
2392{
2393        set_try_to_free_routine(old_try_to_free_routine);
2394        pthread_cond_destroy(&progress_cond);
2395        pthread_mutex_destroy(&read_mutex);
2396        pthread_mutex_destroy(&cache_mutex);
2397        pthread_mutex_destroy(&progress_mutex);
2398}
2399
2400static void *threaded_find_deltas(void *arg)
2401{
2402        struct thread_params *me = arg;
2403
2404        progress_lock();
2405        while (me->remaining) {
2406                progress_unlock();
2407
2408                find_deltas(me->list, &me->remaining,
2409                            me->window, me->depth, me->processed);
2410
2411                progress_lock();
2412                me->working = 0;
2413                pthread_cond_signal(&progress_cond);
2414                progress_unlock();
2415
2416                /*
2417                 * We must not set ->data_ready before we wait on the
2418                 * condition because the main thread may have set it to 1
2419                 * before we get here. In order to be sure that new
2420                 * work is available if we see 1 in ->data_ready, it
2421                 * was initialized to 0 before this thread was spawned
2422                 * and we reset it to 0 right away.
2423                 */
2424                pthread_mutex_lock(&me->mutex);
2425                while (!me->data_ready)
2426                        pthread_cond_wait(&me->cond, &me->mutex);
2427                me->data_ready = 0;
2428                pthread_mutex_unlock(&me->mutex);
2429
2430                progress_lock();
2431        }
2432        progress_unlock();
2433        /* leave ->working 1 so that this doesn't get more work assigned */
2434        return NULL;
2435}
2436
2437static void ll_find_deltas(struct object_entry **list, unsigned list_size,
2438                           int window, int depth, unsigned *processed)
2439{
2440        struct thread_params *p;
2441        int i, ret, active_threads = 0;
2442
2443        init_threaded_search();
2444
2445        if (delta_search_threads <= 1) {
2446                find_deltas(list, &list_size, window, depth, processed);
2447                cleanup_threaded_search();
2448                return;
2449        }
2450        if (progress > pack_to_stdout)
2451                fprintf_ln(stderr, _("Delta compression using up to %d threads"),
2452                           delta_search_threads);
2453        p = xcalloc(delta_search_threads, sizeof(*p));
2454
2455        /* Partition the work amongst work threads. */
2456        for (i = 0; i < delta_search_threads; i++) {
2457                unsigned sub_size = list_size / (delta_search_threads - i);
2458
2459                /* don't use too small segments or no deltas will be found */
2460                if (sub_size < 2*window && i+1 < delta_search_threads)
2461                        sub_size = 0;
2462
2463                p[i].window = window;
2464                p[i].depth = depth;
2465                p[i].processed = processed;
2466                p[i].working = 1;
2467                p[i].data_ready = 0;
2468
2469                /* try to split chunks on "path" boundaries */
2470                while (sub_size && sub_size < list_size &&
2471                       list[sub_size]->hash &&
2472                       list[sub_size]->hash == list[sub_size-1]->hash)
2473                        sub_size++;
2474
2475                p[i].list = list;
2476                p[i].list_size = sub_size;
2477                p[i].remaining = sub_size;
2478
2479                list += sub_size;
2480                list_size -= sub_size;
2481        }
2482
2483        /* Start work threads. */
2484        for (i = 0; i < delta_search_threads; i++) {
2485                if (!p[i].list_size)
2486                        continue;
2487                pthread_mutex_init(&p[i].mutex, NULL);
2488                pthread_cond_init(&p[i].cond, NULL);
2489                ret = pthread_create(&p[i].thread, NULL,
2490                                     threaded_find_deltas, &p[i]);
2491                if (ret)
2492                        die(_("unable to create thread: %s"), strerror(ret));
2493                active_threads++;
2494        }
2495
2496        /*
2497         * Now let's wait for work completion.  Each time a thread is done
2498         * with its work, we steal half of the remaining work from the
2499         * thread with the largest number of unprocessed objects and give
2500         * it to that newly idle thread.  This ensure good load balancing
2501         * until the remaining object list segments are simply too short
2502         * to be worth splitting anymore.
2503         */
2504        while (active_threads) {
2505                struct thread_params *target = NULL;
2506                struct thread_params *victim = NULL;
2507                unsigned sub_size = 0;
2508
2509                progress_lock();
2510                for (;;) {
2511                        for (i = 0; !target && i < delta_search_threads; i++)
2512                                if (!p[i].working)
2513                                        target = &p[i];
2514                        if (target)
2515                                break;
2516                        pthread_cond_wait(&progress_cond, &progress_mutex);
2517                }
2518
2519                for (i = 0; i < delta_search_threads; i++)
2520                        if (p[i].remaining > 2*window &&
2521                            (!victim || victim->remaining < p[i].remaining))
2522                                victim = &p[i];
2523                if (victim) {
2524                        sub_size = victim->remaining / 2;
2525                        list = victim->list + victim->list_size - sub_size;
2526                        while (sub_size && list[0]->hash &&
2527                               list[0]->hash == list[-1]->hash) {
2528                                list++;
2529                                sub_size--;
2530                        }
2531                        if (!sub_size) {
2532                                /*
2533                                 * It is possible for some "paths" to have
2534                                 * so many objects that no hash boundary
2535                                 * might be found.  Let's just steal the
2536                                 * exact half in that case.
2537                                 */
2538                                sub_size = victim->remaining / 2;
2539                                list -= sub_size;
2540                        }
2541                        target->list = list;
2542                        victim->list_size -= sub_size;
2543                        victim->remaining -= sub_size;
2544                }
2545                target->list_size = sub_size;
2546                target->remaining = sub_size;
2547                target->working = 1;
2548                progress_unlock();
2549
2550                pthread_mutex_lock(&target->mutex);
2551                target->data_ready = 1;
2552                pthread_cond_signal(&target->cond);
2553                pthread_mutex_unlock(&target->mutex);
2554
2555                if (!sub_size) {
2556                        pthread_join(target->thread, NULL);
2557                        pthread_cond_destroy(&target->cond);
2558                        pthread_mutex_destroy(&target->mutex);
2559                        active_threads--;
2560                }
2561        }
2562        cleanup_threaded_search();
2563        free(p);
2564}
2565
2566static void add_tag_chain(const struct object_id *oid)
2567{
2568        struct tag *tag;
2569
2570        /*
2571         * We catch duplicates already in add_object_entry(), but we'd
2572         * prefer to do this extra check to avoid having to parse the
2573         * tag at all if we already know that it's being packed (e.g., if
2574         * it was included via bitmaps, we would not have parsed it
2575         * previously).
2576         */
2577        if (packlist_find(&to_pack, oid->hash, NULL))
2578                return;
2579
2580        tag = lookup_tag(the_repository, oid);
2581        while (1) {
2582                if (!tag || parse_tag(tag) || !tag->tagged)
2583                        die(_("unable to pack objects reachable from tag %s"),
2584                            oid_to_hex(oid));
2585
2586                add_object_entry(&tag->object.oid, OBJ_TAG, NULL, 0);
2587
2588                if (tag->tagged->type != OBJ_TAG)
2589                        return;
2590
2591                tag = (struct tag *)tag->tagged;
2592        }
2593}
2594
2595static int add_ref_tag(const char *path, const struct object_id *oid, int flag, void *cb_data)
2596{
2597        struct object_id peeled;
2598
2599        if (starts_with(path, "refs/tags/") && /* is a tag? */
2600            !peel_ref(path, &peeled)    && /* peelable? */
2601            packlist_find(&to_pack, peeled.hash, NULL))      /* object packed? */
2602                add_tag_chain(oid);
2603        return 0;
2604}
2605
2606static void prepare_pack(int window, int depth)
2607{
2608        struct object_entry **delta_list;
2609        uint32_t i, nr_deltas;
2610        unsigned n;
2611
2612        if (use_delta_islands)
2613                resolve_tree_islands(progress, &to_pack);
2614
2615        get_object_details();
2616
2617        /*
2618         * If we're locally repacking then we need to be doubly careful
2619         * from now on in order to make sure no stealth corruption gets
2620         * propagated to the new pack.  Clients receiving streamed packs
2621         * should validate everything they get anyway so no need to incur
2622         * the additional cost here in that case.
2623         */
2624        if (!pack_to_stdout)
2625                do_check_packed_object_crc = 1;
2626
2627        if (!to_pack.nr_objects || !window || !depth)
2628                return;
2629
2630        ALLOC_ARRAY(delta_list, to_pack.nr_objects);
2631        nr_deltas = n = 0;
2632
2633        for (i = 0; i < to_pack.nr_objects; i++) {
2634                struct object_entry *entry = to_pack.objects + i;
2635
2636                if (DELTA(entry))
2637                        /* This happens if we decided to reuse existing
2638                         * delta from a pack.  "reuse_delta &&" is implied.
2639                         */
2640                        continue;
2641
2642                if (!entry->type_valid ||
2643                    oe_size_less_than(&to_pack, entry, 50))
2644                        continue;
2645
2646                if (entry->no_try_delta)
2647                        continue;
2648
2649                if (!entry->preferred_base) {
2650                        nr_deltas++;
2651                        if (oe_type(entry) < 0)
2652                                die(_("unable to get type of object %s"),
2653                                    oid_to_hex(&entry->idx.oid));
2654                } else {
2655                        if (oe_type(entry) < 0) {
2656                                /*
2657                                 * This object is not found, but we
2658                                 * don't have to include it anyway.
2659                                 */
2660                                continue;
2661                        }
2662                }
2663
2664                delta_list[n++] = entry;
2665        }
2666
2667        if (nr_deltas && n > 1) {
2668                unsigned nr_done = 0;
2669                if (progress)
2670                        progress_state = start_progress(_("Compressing objects"),
2671                                                        nr_deltas);
2672                QSORT(delta_list, n, type_size_sort);
2673                ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
2674                stop_progress(&progress_state);
2675                if (nr_done != nr_deltas)
2676                        die(_("inconsistency with delta count"));
2677        }
2678        free(delta_list);
2679}
2680
2681static int git_pack_config(const char *k, const char *v, void *cb)
2682{
2683        if (!strcmp(k, "pack.window")) {
2684                window = git_config_int(k, v);
2685                return 0;
2686        }
2687        if (!strcmp(k, "pack.windowmemory")) {
2688                window_memory_limit = git_config_ulong(k, v);
2689                return 0;
2690        }
2691        if (!strcmp(k, "pack.depth")) {
2692                depth = git_config_int(k, v);
2693                return 0;
2694        }
2695        if (!strcmp(k, "pack.deltacachesize")) {
2696                max_delta_cache_size = git_config_int(k, v);
2697                return 0;
2698        }
2699        if (!strcmp(k, "pack.deltacachelimit")) {
2700                cache_max_small_delta_size = git_config_int(k, v);
2701                return 0;
2702        }
2703        if (!strcmp(k, "pack.writebitmaphashcache")) {
2704                if (git_config_bool(k, v))
2705                        write_bitmap_options |= BITMAP_OPT_HASH_CACHE;
2706                else
2707                        write_bitmap_options &= ~BITMAP_OPT_HASH_CACHE;
2708        }
2709        if (!strcmp(k, "pack.usebitmaps")) {
2710                use_bitmap_index_default = git_config_bool(k, v);
2711                return 0;
2712        }
2713        if (!strcmp(k, "pack.threads")) {
2714                delta_search_threads = git_config_int(k, v);
2715                if (delta_search_threads < 0)
2716                        die(_("invalid number of threads specified (%d)"),
2717                            delta_search_threads);
2718                if (!HAVE_THREADS && delta_search_threads != 1) {
2719                        warning(_("no threads support, ignoring %s"), k);
2720                        delta_search_threads = 0;
2721                }
2722                return 0;
2723        }
2724        if (!strcmp(k, "pack.indexversion")) {
2725                pack_idx_opts.version = git_config_int(k, v);
2726                if (pack_idx_opts.version > 2)
2727                        die(_("bad pack.indexversion=%"PRIu32),
2728                            pack_idx_opts.version);
2729                return 0;
2730        }
2731        return git_default_config(k, v, cb);
2732}
2733
2734static void read_object_list_from_stdin(void)
2735{
2736        char line[GIT_MAX_HEXSZ + 1 + PATH_MAX + 2];
2737        struct object_id oid;
2738        const char *p;
2739
2740        for (;;) {
2741                if (!fgets(line, sizeof(line), stdin)) {
2742                        if (feof(stdin))
2743                                break;
2744                        if (!ferror(stdin))
2745                                die("BUG: fgets returned NULL, not EOF, not error!");
2746                        if (errno != EINTR)
2747                                die_errno("fgets");
2748                        clearerr(stdin);
2749                        continue;
2750                }
2751                if (line[0] == '-') {
2752                        if (get_oid_hex(line+1, &oid))
2753                                die(_("expected edge object ID, got garbage:\n %s"),
2754                                    line);
2755                        add_preferred_base(&oid);
2756                        continue;
2757                }
2758                if (parse_oid_hex(line, &oid, &p))
2759                        die(_("expected object ID, got garbage:\n %s"), line);
2760
2761                add_preferred_base_object(p + 1);
2762                add_object_entry(&oid, OBJ_NONE, p + 1, 0);
2763        }
2764}
2765
2766/* Remember to update object flag allocation in object.h */
2767#define OBJECT_ADDED (1u<<20)
2768
2769static void show_commit(struct commit *commit, void *data)
2770{
2771        add_object_entry(&commit->object.oid, OBJ_COMMIT, NULL, 0);
2772        commit->object.flags |= OBJECT_ADDED;
2773
2774        if (write_bitmap_index)
2775                index_commit_for_bitmap(commit);
2776
2777        if (use_delta_islands)
2778                propagate_island_marks(commit);
2779}
2780
2781static void show_object(struct object *obj, const char *name, void *data)
2782{
2783        add_preferred_base_object(name);
2784        add_object_entry(&obj->oid, obj->type, name, 0);
2785        obj->flags |= OBJECT_ADDED;
2786
2787        if (use_delta_islands) {
2788                const char *p;
2789                unsigned depth;
2790                struct object_entry *ent;
2791
2792                /* the empty string is a root tree, which is depth 0 */
2793                depth = *name ? 1 : 0;
2794                for (p = strchr(name, '/'); p; p = strchr(p + 1, '/'))
2795                        depth++;
2796
2797                ent = packlist_find(&to_pack, obj->oid.hash, NULL);
2798                if (ent && depth > oe_tree_depth(&to_pack, ent))
2799                        oe_set_tree_depth(&to_pack, ent, depth);
2800        }
2801}
2802
2803static void show_object__ma_allow_any(struct object *obj, const char *name, void *data)
2804{
2805        assert(arg_missing_action == MA_ALLOW_ANY);
2806
2807        /*
2808         * Quietly ignore ALL missing objects.  This avoids problems with
2809         * staging them now and getting an odd error later.
2810         */
2811        if (!has_object_file(&obj->oid))
2812                return;
2813
2814        show_object(obj, name, data);
2815}
2816
2817static void show_object__ma_allow_promisor(struct object *obj, const char *name, void *data)
2818{
2819        assert(arg_missing_action == MA_ALLOW_PROMISOR);
2820
2821        /*
2822         * Quietly ignore EXPECTED missing objects.  This avoids problems with
2823         * staging them now and getting an odd error later.
2824         */
2825        if (!has_object_file(&obj->oid) && is_promisor_object(&obj->oid))
2826                return;
2827
2828        show_object(obj, name, data);
2829}
2830
2831static int option_parse_missing_action(const struct option *opt,
2832                                       const char *arg, int unset)
2833{
2834        assert(arg);
2835        assert(!unset);
2836
2837        if (!strcmp(arg, "error")) {
2838                arg_missing_action = MA_ERROR;
2839                fn_show_object = show_object;
2840                return 0;
2841        }
2842
2843        if (!strcmp(arg, "allow-any")) {
2844                arg_missing_action = MA_ALLOW_ANY;
2845                fetch_if_missing = 0;
2846                fn_show_object = show_object__ma_allow_any;
2847                return 0;
2848        }
2849
2850        if (!strcmp(arg, "allow-promisor")) {
2851                arg_missing_action = MA_ALLOW_PROMISOR;
2852                fetch_if_missing = 0;
2853                fn_show_object = show_object__ma_allow_promisor;
2854                return 0;
2855        }
2856
2857        die(_("invalid value for --missing"));
2858        return 0;
2859}
2860
2861static void show_edge(struct commit *commit)
2862{
2863        add_preferred_base(&commit->object.oid);
2864}
2865
2866struct in_pack_object {
2867        off_t offset;
2868        struct object *object;
2869};
2870
2871struct in_pack {
2872        unsigned int alloc;
2873        unsigned int nr;
2874        struct in_pack_object *array;
2875};
2876
2877static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
2878{
2879        in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->oid.hash, p);
2880        in_pack->array[in_pack->nr].object = object;
2881        in_pack->nr++;
2882}
2883
2884/*
2885 * Compare the objects in the offset order, in order to emulate the
2886 * "git rev-list --objects" output that produced the pack originally.
2887 */
2888static int ofscmp(const void *a_, const void *b_)
2889{
2890        struct in_pack_object *a = (struct in_pack_object *)a_;
2891        struct in_pack_object *b = (struct in_pack_object *)b_;
2892
2893        if (a->offset < b->offset)
2894                return -1;
2895        else if (a->offset > b->offset)
2896                return 1;
2897        else
2898                return oidcmp(&a->object->oid, &b->object->oid);
2899}
2900
2901static void add_objects_in_unpacked_packs(struct rev_info *revs)
2902{
2903        struct packed_git *p;
2904        struct in_pack in_pack;
2905        uint32_t i;
2906
2907        memset(&in_pack, 0, sizeof(in_pack));
2908
2909        for (p = get_all_packs(the_repository); p; p = p->next) {
2910                struct object_id oid;
2911                struct object *o;
2912
2913                if (!p->pack_local || p->pack_keep || p->pack_keep_in_core)
2914                        continue;
2915                if (open_pack_index(p))
2916                        die(_("cannot open pack index"));
2917
2918                ALLOC_GROW(in_pack.array,
2919                           in_pack.nr + p->num_objects,
2920                           in_pack.alloc);
2921
2922                for (i = 0; i < p->num_objects; i++) {
2923                        nth_packed_object_oid(&oid, p, i);
2924                        o = lookup_unknown_object(oid.hash);
2925                        if (!(o->flags & OBJECT_ADDED))
2926                                mark_in_pack_object(o, p, &in_pack);
2927                        o->flags |= OBJECT_ADDED;
2928                }
2929        }
2930
2931        if (in_pack.nr) {
2932                QSORT(in_pack.array, in_pack.nr, ofscmp);
2933                for (i = 0; i < in_pack.nr; i++) {
2934                        struct object *o = in_pack.array[i].object;
2935                        add_object_entry(&o->oid, o->type, "", 0);
2936                }
2937        }
2938        free(in_pack.array);
2939}
2940
2941static int add_loose_object(const struct object_id *oid, const char *path,
2942                            void *data)
2943{
2944        enum object_type type = oid_object_info(the_repository, oid, NULL);
2945
2946        if (type < 0) {
2947                warning(_("loose object at %s could not be examined"), path);
2948                return 0;
2949        }
2950
2951        add_object_entry(oid, type, "", 0);
2952        return 0;
2953}
2954
2955/*
2956 * We actually don't even have to worry about reachability here.
2957 * add_object_entry will weed out duplicates, so we just add every
2958 * loose object we find.
2959 */
2960static void add_unreachable_loose_objects(void)
2961{
2962        for_each_loose_file_in_objdir(get_object_directory(),
2963                                      add_loose_object,
2964                                      NULL, NULL, NULL);
2965}
2966
2967static int has_sha1_pack_kept_or_nonlocal(const struct object_id *oid)
2968{
2969        static struct packed_git *last_found = (void *)1;
2970        struct packed_git *p;
2971
2972        p = (last_found != (void *)1) ? last_found :
2973                                        get_all_packs(the_repository);
2974
2975        while (p) {
2976                if ((!p->pack_local || p->pack_keep ||
2977                                p->pack_keep_in_core) &&
2978                        find_pack_entry_one(oid->hash, p)) {
2979                        last_found = p;
2980                        return 1;
2981                }
2982                if (p == last_found)
2983                        p = get_all_packs(the_repository);
2984                else
2985                        p = p->next;
2986                if (p == last_found)
2987                        p = p->next;
2988        }
2989        return 0;
2990}
2991
2992/*
2993 * Store a list of sha1s that are should not be discarded
2994 * because they are either written too recently, or are
2995 * reachable from another object that was.
2996 *
2997 * This is filled by get_object_list.
2998 */
2999static struct oid_array recent_objects;
3000
3001static int loosened_object_can_be_discarded(const struct object_id *oid,
3002                                            timestamp_t mtime)
3003{
3004        if (!unpack_unreachable_expiration)
3005                return 0;
3006        if (mtime > unpack_unreachable_expiration)
3007                return 0;
3008        if (oid_array_lookup(&recent_objects, oid) >= 0)
3009                return 0;
3010        return 1;
3011}
3012
3013static void loosen_unused_packed_objects(struct rev_info *revs)
3014{
3015        struct packed_git *p;
3016        uint32_t i;
3017        struct object_id oid;
3018
3019        for (p = get_all_packs(the_repository); p; p = p->next) {
3020                if (!p->pack_local || p->pack_keep || p->pack_keep_in_core)
3021                        continue;
3022
3023                if (open_pack_index(p))
3024                        die(_("cannot open pack index"));
3025
3026                for (i = 0; i < p->num_objects; i++) {
3027                        nth_packed_object_oid(&oid, p, i);
3028                        if (!packlist_find(&to_pack, oid.hash, NULL) &&
3029                            !has_sha1_pack_kept_or_nonlocal(&oid) &&
3030                            !loosened_object_can_be_discarded(&oid, p->mtime))
3031                                if (force_object_loose(&oid, p->mtime))
3032                                        die(_("unable to force loose object"));
3033                }
3034        }
3035}
3036
3037/*
3038 * This tracks any options which pack-reuse code expects to be on, or which a
3039 * reader of the pack might not understand, and which would therefore prevent
3040 * blind reuse of what we have on disk.
3041 */
3042static int pack_options_allow_reuse(void)
3043{
3044        return pack_to_stdout &&
3045               allow_ofs_delta &&
3046               !ignore_packed_keep_on_disk &&
3047               !ignore_packed_keep_in_core &&
3048               (!local || !have_non_local_packs) &&
3049               !incremental;
3050}
3051
3052static int get_object_list_from_bitmap(struct rev_info *revs)
3053{
3054        if (!(bitmap_git = prepare_bitmap_walk(revs)))
3055                return -1;
3056
3057        if (pack_options_allow_reuse() &&
3058            !reuse_partial_packfile_from_bitmap(
3059                        bitmap_git,
3060                        &reuse_packfile,
3061                        &reuse_packfile_objects,
3062                        &reuse_packfile_offset)) {
3063                assert(reuse_packfile_objects);
3064                nr_result += reuse_packfile_objects;
3065                display_progress(progress_state, nr_result);
3066        }
3067
3068        traverse_bitmap_commit_list(bitmap_git, &add_object_entry_from_bitmap);
3069        return 0;
3070}
3071
3072static void record_recent_object(struct object *obj,
3073                                 const char *name,
3074                                 void *data)
3075{
3076        oid_array_append(&recent_objects, &obj->oid);
3077}
3078
3079static void record_recent_commit(struct commit *commit, void *data)
3080{
3081        oid_array_append(&recent_objects, &commit->object.oid);
3082}
3083
3084static void get_object_list(int ac, const char **av)
3085{
3086        struct rev_info revs;
3087        char line[1000];
3088        int flags = 0;
3089        int save_warning;
3090
3091        repo_init_revisions(the_repository, &revs, NULL);
3092        save_commit_buffer = 0;
3093        revs.allow_exclude_promisor_objects_opt = 1;
3094        setup_revisions(ac, av, &revs, NULL);
3095
3096        /* make sure shallows are read */
3097        is_repository_shallow(the_repository);
3098
3099        save_warning = warn_on_object_refname_ambiguity;
3100        warn_on_object_refname_ambiguity = 0;
3101
3102        while (fgets(line, sizeof(line), stdin) != NULL) {
3103                int len = strlen(line);
3104                if (len && line[len - 1] == '\n')
3105                        line[--len] = 0;
3106                if (!len)
3107                        break;
3108                if (*line == '-') {
3109                        if (!strcmp(line, "--not")) {
3110                                flags ^= UNINTERESTING;
3111                                write_bitmap_index = 0;
3112                                continue;
3113                        }
3114                        if (starts_with(line, "--shallow ")) {
3115                                struct object_id oid;
3116                                if (get_oid_hex(line + 10, &oid))
3117                                        die("not an SHA-1 '%s'", line + 10);
3118                                register_shallow(the_repository, &oid);
3119                                use_bitmap_index = 0;
3120                                continue;
3121                        }
3122                        die(_("not a rev '%s'"), line);
3123                }
3124                if (handle_revision_arg(line, &revs, flags, REVARG_CANNOT_BE_FILENAME))
3125                        die(_("bad revision '%s'"), line);
3126        }
3127
3128        warn_on_object_refname_ambiguity = save_warning;
3129
3130        if (use_bitmap_index && !get_object_list_from_bitmap(&revs))
3131                return;
3132
3133        if (use_delta_islands)
3134                load_delta_islands();
3135
3136        if (prepare_revision_walk(&revs))
3137                die(_("revision walk setup failed"));
3138        mark_edges_uninteresting(&revs, show_edge);
3139
3140        if (!fn_show_object)
3141                fn_show_object = show_object;
3142        traverse_commit_list_filtered(&filter_options, &revs,
3143                                      show_commit, fn_show_object, NULL,
3144                                      NULL);
3145
3146        if (unpack_unreachable_expiration) {
3147                revs.ignore_missing_links = 1;
3148                if (add_unseen_recent_objects_to_traversal(&revs,
3149                                unpack_unreachable_expiration))
3150                        die(_("unable to add recent objects"));
3151                if (prepare_revision_walk(&revs))
3152                        die(_("revision walk setup failed"));
3153                traverse_commit_list(&revs, record_recent_commit,
3154                                     record_recent_object, NULL);
3155        }
3156
3157        if (keep_unreachable)
3158                add_objects_in_unpacked_packs(&revs);
3159        if (pack_loose_unreachable)
3160                add_unreachable_loose_objects();
3161        if (unpack_unreachable)
3162                loosen_unused_packed_objects(&revs);
3163
3164        oid_array_clear(&recent_objects);
3165}
3166
3167static void add_extra_kept_packs(const struct string_list *names)
3168{
3169        struct packed_git *p;
3170
3171        if (!names->nr)
3172                return;
3173
3174        for (p = get_all_packs(the_repository); p; p = p->next) {
3175                const char *name = basename(p->pack_name);
3176                int i;
3177
3178                if (!p->pack_local)
3179                        continue;
3180
3181                for (i = 0; i < names->nr; i++)
3182                        if (!fspathcmp(name, names->items[i].string))
3183                                break;
3184
3185                if (i < names->nr) {
3186                        p->pack_keep_in_core = 1;
3187                        ignore_packed_keep_in_core = 1;
3188                        continue;
3189                }
3190        }
3191}
3192
3193static int option_parse_index_version(const struct option *opt,
3194                                      const char *arg, int unset)
3195{
3196        char *c;
3197        const char *val = arg;
3198
3199        BUG_ON_OPT_NEG(unset);
3200
3201        pack_idx_opts.version = strtoul(val, &c, 10);
3202        if (pack_idx_opts.version > 2)
3203                die(_("unsupported index version %s"), val);
3204        if (*c == ',' && c[1])
3205                pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
3206        if (*c || pack_idx_opts.off32_limit & 0x80000000)
3207                die(_("bad index version '%s'"), val);
3208        return 0;
3209}
3210
3211static int option_parse_unpack_unreachable(const struct option *opt,
3212                                           const char *arg, int unset)
3213{
3214        if (unset) {
3215                unpack_unreachable = 0;
3216                unpack_unreachable_expiration = 0;
3217        }
3218        else {
3219                unpack_unreachable = 1;
3220                if (arg)
3221                        unpack_unreachable_expiration = approxidate(arg);
3222        }
3223        return 0;
3224}
3225
3226int cmd_pack_objects(int argc, const char **argv, const char *prefix)
3227{
3228        int use_internal_rev_list = 0;
3229        int shallow = 0;
3230        int all_progress_implied = 0;
3231        struct argv_array rp = ARGV_ARRAY_INIT;
3232        int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
3233        int rev_list_index = 0;
3234        struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
3235        struct option pack_objects_options[] = {
3236                OPT_SET_INT('q', "quiet", &progress,
3237                            N_("do not show progress meter"), 0),
3238                OPT_SET_INT(0, "progress", &progress,
3239                            N_("show progress meter"), 1),
3240                OPT_SET_INT(0, "all-progress", &progress,
3241                            N_("show progress meter during object writing phase"), 2),
3242                OPT_BOOL(0, "all-progress-implied",
3243                         &all_progress_implied,
3244                         N_("similar to --all-progress when progress meter is shown")),
3245                { OPTION_CALLBACK, 0, "index-version", NULL, N_("<version>[,<offset>]"),
3246                  N_("write the pack index file in the specified idx format version"),
3247                  PARSE_OPT_NONEG, option_parse_index_version },
3248                OPT_MAGNITUDE(0, "max-pack-size", &pack_size_limit,
3249                              N_("maximum size of each output pack file")),
3250                OPT_BOOL(0, "local", &local,
3251                         N_("ignore borrowed objects from alternate object store")),
3252                OPT_BOOL(0, "incremental", &incremental,
3253                         N_("ignore packed objects")),
3254                OPT_INTEGER(0, "window", &window,
3255                            N_("limit pack window by objects")),
3256                OPT_MAGNITUDE(0, "window-memory", &window_memory_limit,
3257                              N_("limit pack window by memory in addition to object limit")),
3258                OPT_INTEGER(0, "depth", &depth,
3259                            N_("maximum length of delta chain allowed in the resulting pack")),
3260                OPT_BOOL(0, "reuse-delta", &reuse_delta,
3261                         N_("reuse existing deltas")),
3262                OPT_BOOL(0, "reuse-object", &reuse_object,
3263                         N_("reuse existing objects")),
3264                OPT_BOOL(0, "delta-base-offset", &allow_ofs_delta,
3265                         N_("use OFS_DELTA objects")),
3266                OPT_INTEGER(0, "threads", &delta_search_threads,
3267                            N_("use threads when searching for best delta matches")),
3268                OPT_BOOL(0, "non-empty", &non_empty,
3269                         N_("do not create an empty pack output")),
3270                OPT_BOOL(0, "revs", &use_internal_rev_list,
3271                         N_("read revision arguments from standard input")),
3272                OPT_SET_INT_F(0, "unpacked", &rev_list_unpacked,
3273                              N_("limit the objects to those that are not yet packed"),
3274                              1, PARSE_OPT_NONEG),
3275                OPT_SET_INT_F(0, "all", &rev_list_all,
3276                              N_("include objects reachable from any reference"),
3277                              1, PARSE_OPT_NONEG),
3278                OPT_SET_INT_F(0, "reflog", &rev_list_reflog,
3279                              N_("include objects referred by reflog entries"),
3280                              1, PARSE_OPT_NONEG),
3281                OPT_SET_INT_F(0, "indexed-objects", &rev_list_index,
3282                              N_("include objects referred to by the index"),
3283                              1, PARSE_OPT_NONEG),
3284                OPT_BOOL(0, "stdout", &pack_to_stdout,
3285                         N_("output pack to stdout")),
3286                OPT_BOOL(0, "include-tag", &include_tag,
3287                         N_("include tag objects that refer to objects to be packed")),
3288                OPT_BOOL(0, "keep-unreachable", &keep_unreachable,
3289                         N_("keep unreachable objects")),
3290                OPT_BOOL(0, "pack-loose-unreachable", &pack_loose_unreachable,
3291                         N_("pack loose unreachable objects")),
3292                { OPTION_CALLBACK, 0, "unpack-unreachable", NULL, N_("time"),
3293                  N_("unpack unreachable objects newer than <time>"),
3294                  PARSE_OPT_OPTARG, option_parse_unpack_unreachable },
3295                OPT_BOOL(0, "thin", &thin,
3296                         N_("create thin packs")),
3297                OPT_BOOL(0, "shallow", &shallow,
3298                         N_("create packs suitable for shallow fetches")),
3299                OPT_BOOL(0, "honor-pack-keep", &ignore_packed_keep_on_disk,
3300                         N_("ignore packs that have companion .keep file")),
3301                OPT_STRING_LIST(0, "keep-pack", &keep_pack_list, N_("name"),
3302                                N_("ignore this pack")),
3303                OPT_INTEGER(0, "compression", &pack_compression_level,
3304                            N_("pack compression level")),
3305                OPT_SET_INT(0, "keep-true-parents", &grafts_replace_parents,
3306                            N_("do not hide commits by grafts"), 0),
3307                OPT_BOOL(0, "use-bitmap-index", &use_bitmap_index,
3308                         N_("use a bitmap index if available to speed up counting objects")),
3309                OPT_BOOL(0, "write-bitmap-index", &write_bitmap_index,
3310                         N_("write a bitmap index together with the pack index")),
3311                OPT_PARSE_LIST_OBJECTS_FILTER(&filter_options),
3312                { OPTION_CALLBACK, 0, "missing", NULL, N_("action"),
3313                  N_("handling for missing objects"), PARSE_OPT_NONEG,
3314                  option_parse_missing_action },
3315                OPT_BOOL(0, "exclude-promisor-objects", &exclude_promisor_objects,
3316                         N_("do not pack objects in promisor packfiles")),
3317                OPT_BOOL(0, "delta-islands", &use_delta_islands,
3318                         N_("respect islands during delta compression")),
3319                OPT_END(),
3320        };
3321
3322        if (DFS_NUM_STATES > (1 << OE_DFS_STATE_BITS))
3323                BUG("too many dfs states, increase OE_DFS_STATE_BITS");
3324
3325        read_replace_refs = 0;
3326
3327        reset_pack_idx_option(&pack_idx_opts);
3328        git_config(git_pack_config, NULL);
3329
3330        progress = isatty(2);
3331        argc = parse_options(argc, argv, prefix, pack_objects_options,
3332                             pack_usage, 0);
3333
3334        if (argc) {
3335                base_name = argv[0];
3336                argc--;
3337        }
3338        if (pack_to_stdout != !base_name || argc)
3339                usage_with_options(pack_usage, pack_objects_options);
3340
3341        if (depth >= (1 << OE_DEPTH_BITS)) {
3342                warning(_("delta chain depth %d is too deep, forcing %d"),
3343                        depth, (1 << OE_DEPTH_BITS) - 1);
3344                depth = (1 << OE_DEPTH_BITS) - 1;
3345        }
3346        if (cache_max_small_delta_size >= (1U << OE_Z_DELTA_BITS)) {
3347                warning(_("pack.deltaCacheLimit is too high, forcing %d"),
3348                        (1U << OE_Z_DELTA_BITS) - 1);
3349                cache_max_small_delta_size = (1U << OE_Z_DELTA_BITS) - 1;
3350        }
3351
3352        argv_array_push(&rp, "pack-objects");
3353        if (thin) {
3354                use_internal_rev_list = 1;
3355                argv_array_push(&rp, shallow
3356                                ? "--objects-edge-aggressive"
3357                                : "--objects-edge");
3358        } else
3359                argv_array_push(&rp, "--objects");
3360
3361        if (rev_list_all) {
3362                use_internal_rev_list = 1;
3363                argv_array_push(&rp, "--all");
3364        }
3365        if (rev_list_reflog) {
3366                use_internal_rev_list = 1;
3367                argv_array_push(&rp, "--reflog");
3368        }
3369        if (rev_list_index) {
3370                use_internal_rev_list = 1;
3371                argv_array_push(&rp, "--indexed-objects");
3372        }
3373        if (rev_list_unpacked) {
3374                use_internal_rev_list = 1;
3375                argv_array_push(&rp, "--unpacked");
3376        }
3377
3378        if (exclude_promisor_objects) {
3379                use_internal_rev_list = 1;
3380                fetch_if_missing = 0;
3381                argv_array_push(&rp, "--exclude-promisor-objects");
3382        }
3383        if (unpack_unreachable || keep_unreachable || pack_loose_unreachable)
3384                use_internal_rev_list = 1;
3385
3386        if (!reuse_object)
3387                reuse_delta = 0;
3388        if (pack_compression_level == -1)
3389                pack_compression_level = Z_DEFAULT_COMPRESSION;
3390        else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
3391                die(_("bad pack compression level %d"), pack_compression_level);
3392
3393        if (!delta_search_threads)      /* --threads=0 means autodetect */
3394                delta_search_threads = online_cpus();
3395
3396        if (!HAVE_THREADS && delta_search_threads != 1)
3397                warning(_("no threads support, ignoring --threads"));
3398        if (!pack_to_stdout && !pack_size_limit)
3399                pack_size_limit = pack_size_limit_cfg;
3400        if (pack_to_stdout && pack_size_limit)
3401                die(_("--max-pack-size cannot be used to build a pack for transfer"));
3402        if (pack_size_limit && pack_size_limit < 1024*1024) {
3403                warning(_("minimum pack size limit is 1 MiB"));
3404                pack_size_limit = 1024*1024;
3405        }
3406
3407        if (!pack_to_stdout && thin)
3408                die(_("--thin cannot be used to build an indexable pack"));
3409
3410        if (keep_unreachable && unpack_unreachable)
3411                die(_("--keep-unreachable and --unpack-unreachable are incompatible"));
3412        if (!rev_list_all || !rev_list_reflog || !rev_list_index)
3413                unpack_unreachable_expiration = 0;
3414
3415        if (filter_options.choice) {
3416                if (!pack_to_stdout)
3417                        die(_("cannot use --filter without --stdout"));
3418                use_bitmap_index = 0;
3419        }
3420
3421        /*
3422         * "soft" reasons not to use bitmaps - for on-disk repack by default we want
3423         *
3424         * - to produce good pack (with bitmap index not-yet-packed objects are
3425         *   packed in suboptimal order).
3426         *
3427         * - to use more robust pack-generation codepath (avoiding possible
3428         *   bugs in bitmap code and possible bitmap index corruption).
3429         */
3430        if (!pack_to_stdout)
3431                use_bitmap_index_default = 0;
3432
3433        if (use_bitmap_index < 0)
3434                use_bitmap_index = use_bitmap_index_default;
3435
3436        /* "hard" reasons not to use bitmaps; these just won't work at all */
3437        if (!use_internal_rev_list || (!pack_to_stdout && write_bitmap_index) || is_repository_shallow(the_repository))
3438                use_bitmap_index = 0;
3439
3440        if (pack_to_stdout || !rev_list_all)
3441                write_bitmap_index = 0;
3442
3443        if (use_delta_islands)
3444                argv_array_push(&rp, "--topo-order");
3445
3446        if (progress && all_progress_implied)
3447                progress = 2;
3448
3449        add_extra_kept_packs(&keep_pack_list);
3450        if (ignore_packed_keep_on_disk) {
3451                struct packed_git *p;
3452                for (p = get_all_packs(the_repository); p; p = p->next)
3453                        if (p->pack_local && p->pack_keep)
3454                                break;
3455                if (!p) /* no keep-able packs found */
3456                        ignore_packed_keep_on_disk = 0;
3457        }
3458        if (local) {
3459                /*
3460                 * unlike ignore_packed_keep_on_disk above, we do not
3461                 * want to unset "local" based on looking at packs, as
3462                 * it also covers non-local objects
3463                 */
3464                struct packed_git *p;
3465                for (p = get_all_packs(the_repository); p; p = p->next) {
3466                        if (!p->pack_local) {
3467                                have_non_local_packs = 1;
3468                                break;
3469                        }
3470                }
3471        }
3472
3473        prepare_packing_data(&to_pack);
3474
3475        if (progress)
3476                progress_state = start_progress(_("Enumerating objects"), 0);
3477        if (!use_internal_rev_list)
3478                read_object_list_from_stdin();
3479        else {
3480                get_object_list(rp.argc, rp.argv);
3481                argv_array_clear(&rp);
3482        }
3483        cleanup_preferred_base();
3484        if (include_tag && nr_result)
3485                for_each_ref(add_ref_tag, NULL);
3486        stop_progress(&progress_state);
3487
3488        if (non_empty && !nr_result)
3489                return 0;
3490        if (nr_result)
3491                prepare_pack(window, depth);
3492        write_pack_file();
3493        if (progress)
3494                fprintf_ln(stderr,
3495                           _("Total %"PRIu32" (delta %"PRIu32"),"
3496                             " reused %"PRIu32" (delta %"PRIu32")"),
3497                           written, written_delta, reused, reused_delta);
3498        return 0;
3499}