builtin / pack-objects.con commit Merge branch 'nd/tree-walk-with-repo' (1eb0a12)
   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#include "trace2.h"
  37
  38#define IN_PACK(obj) oe_in_pack(&to_pack, obj)
  39#define SIZE(obj) oe_size(&to_pack, obj)
  40#define SET_SIZE(obj,size) oe_set_size(&to_pack, obj, size)
  41#define DELTA_SIZE(obj) oe_delta_size(&to_pack, obj)
  42#define DELTA(obj) oe_delta(&to_pack, obj)
  43#define DELTA_CHILD(obj) oe_delta_child(&to_pack, obj)
  44#define DELTA_SIBLING(obj) oe_delta_sibling(&to_pack, obj)
  45#define SET_DELTA(obj, val) oe_set_delta(&to_pack, obj, val)
  46#define SET_DELTA_EXT(obj, oid) oe_set_delta_ext(&to_pack, obj, oid)
  47#define SET_DELTA_SIZE(obj, val) oe_set_delta_size(&to_pack, obj, val)
  48#define SET_DELTA_CHILD(obj, val) oe_set_delta_child(&to_pack, obj, val)
  49#define SET_DELTA_SIBLING(obj, val) oe_set_delta_sibling(&to_pack, obj, val)
  50
  51static const char *pack_usage[] = {
  52        N_("git pack-objects --stdout [<options>...] [< <ref-list> | < <object-list>]"),
  53        N_("git pack-objects [<options>...] <base-name> [< <ref-list> | < <object-list>]"),
  54        NULL
  55};
  56
  57/*
  58 * Objects we are going to pack are collected in the `to_pack` structure.
  59 * It contains an array (dynamically expanded) of the object data, and a map
  60 * that can resolve SHA1s to their position in the array.
  61 */
  62static struct packing_data to_pack;
  63
  64static struct pack_idx_entry **written_list;
  65static uint32_t nr_result, nr_written, nr_seen;
  66static struct bitmap_index *bitmap_git;
  67static uint32_t write_layer;
  68
  69static int non_empty;
  70static int reuse_delta = 1, reuse_object = 1;
  71static int keep_unreachable, unpack_unreachable, include_tag;
  72static timestamp_t unpack_unreachable_expiration;
  73static int pack_loose_unreachable;
  74static int local;
  75static int have_non_local_packs;
  76static int incremental;
  77static int ignore_packed_keep_on_disk;
  78static int ignore_packed_keep_in_core;
  79static int allow_ofs_delta;
  80static struct pack_idx_option pack_idx_opts;
  81static const char *base_name;
  82static int progress = 1;
  83static int window = 10;
  84static unsigned long pack_size_limit;
  85static int depth = 50;
  86static int delta_search_threads;
  87static int pack_to_stdout;
  88static int sparse;
  89static int thin;
  90static int num_preferred_base;
  91static struct progress *progress_state;
  92
  93static struct packed_git *reuse_packfile;
  94static uint32_t reuse_packfile_objects;
  95static off_t reuse_packfile_offset;
  96
  97static int use_bitmap_index_default = 1;
  98static int use_bitmap_index = -1;
  99static int write_bitmap_index;
 100static uint16_t write_bitmap_options = BITMAP_OPT_HASH_CACHE;
 101
 102static int exclude_promisor_objects;
 103
 104static int use_delta_islands;
 105
 106static unsigned long delta_cache_size = 0;
 107static unsigned long max_delta_cache_size = DEFAULT_DELTA_CACHE_SIZE;
 108static unsigned long cache_max_small_delta_size = 1000;
 109
 110static unsigned long window_memory_limit = 0;
 111
 112static struct list_objects_filter_options filter_options;
 113
 114enum missing_action {
 115        MA_ERROR = 0,      /* fail if any missing objects are encountered */
 116        MA_ALLOW_ANY,      /* silently allow ALL missing objects */
 117        MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
 118};
 119static enum missing_action arg_missing_action;
 120static show_object_fn fn_show_object;
 121
 122/*
 123 * stats
 124 */
 125static uint32_t written, written_delta;
 126static uint32_t reused, reused_delta;
 127
 128/*
 129 * Indexed commits
 130 */
 131static struct commit **indexed_commits;
 132static unsigned int indexed_commits_nr;
 133static unsigned int indexed_commits_alloc;
 134
 135static void index_commit_for_bitmap(struct commit *commit)
 136{
 137        if (indexed_commits_nr >= indexed_commits_alloc) {
 138                indexed_commits_alloc = (indexed_commits_alloc + 32) * 2;
 139                REALLOC_ARRAY(indexed_commits, indexed_commits_alloc);
 140        }
 141
 142        indexed_commits[indexed_commits_nr++] = commit;
 143}
 144
 145static void *get_delta(struct object_entry *entry)
 146{
 147        unsigned long size, base_size, delta_size;
 148        void *buf, *base_buf, *delta_buf;
 149        enum object_type type;
 150
 151        buf = read_object_file(&entry->idx.oid, &type, &size);
 152        if (!buf)
 153                die(_("unable to read %s"), oid_to_hex(&entry->idx.oid));
 154        base_buf = read_object_file(&DELTA(entry)->idx.oid, &type,
 155                                    &base_size);
 156        if (!base_buf)
 157                die("unable to read %s",
 158                    oid_to_hex(&DELTA(entry)->idx.oid));
 159        delta_buf = diff_delta(base_buf, base_size,
 160                               buf, size, &delta_size, 0);
 161        /*
 162         * We succesfully computed this delta once but dropped it for
 163         * memory reasons. Something is very wrong if this time we
 164         * recompute and create a different delta.
 165         */
 166        if (!delta_buf || delta_size != DELTA_SIZE(entry))
 167                BUG("delta size changed");
 168        free(buf);
 169        free(base_buf);
 170        return delta_buf;
 171}
 172
 173static unsigned long do_compress(void **pptr, unsigned long size)
 174{
 175        git_zstream stream;
 176        void *in, *out;
 177        unsigned long maxsize;
 178
 179        git_deflate_init(&stream, pack_compression_level);
 180        maxsize = git_deflate_bound(&stream, size);
 181
 182        in = *pptr;
 183        out = xmalloc(maxsize);
 184        *pptr = out;
 185
 186        stream.next_in = in;
 187        stream.avail_in = size;
 188        stream.next_out = out;
 189        stream.avail_out = maxsize;
 190        while (git_deflate(&stream, Z_FINISH) == Z_OK)
 191                ; /* nothing */
 192        git_deflate_end(&stream);
 193
 194        free(in);
 195        return stream.total_out;
 196}
 197
 198static unsigned long write_large_blob_data(struct git_istream *st, struct hashfile *f,
 199                                           const struct object_id *oid)
 200{
 201        git_zstream stream;
 202        unsigned char ibuf[1024 * 16];
 203        unsigned char obuf[1024 * 16];
 204        unsigned long olen = 0;
 205
 206        git_deflate_init(&stream, pack_compression_level);
 207
 208        for (;;) {
 209                ssize_t readlen;
 210                int zret = Z_OK;
 211                readlen = read_istream(st, ibuf, sizeof(ibuf));
 212                if (readlen == -1)
 213                        die(_("unable to read %s"), oid_to_hex(oid));
 214
 215                stream.next_in = ibuf;
 216                stream.avail_in = readlen;
 217                while ((stream.avail_in || readlen == 0) &&
 218                       (zret == Z_OK || zret == Z_BUF_ERROR)) {
 219                        stream.next_out = obuf;
 220                        stream.avail_out = sizeof(obuf);
 221                        zret = git_deflate(&stream, readlen ? 0 : Z_FINISH);
 222                        hashwrite(f, obuf, stream.next_out - obuf);
 223                        olen += stream.next_out - obuf;
 224                }
 225                if (stream.avail_in)
 226                        die(_("deflate error (%d)"), zret);
 227                if (readlen == 0) {
 228                        if (zret != Z_STREAM_END)
 229                                die(_("deflate error (%d)"), zret);
 230                        break;
 231                }
 232        }
 233        git_deflate_end(&stream);
 234        return olen;
 235}
 236
 237/*
 238 * we are going to reuse the existing object data as is.  make
 239 * sure it is not corrupt.
 240 */
 241static int check_pack_inflate(struct packed_git *p,
 242                struct pack_window **w_curs,
 243                off_t offset,
 244                off_t len,
 245                unsigned long expect)
 246{
 247        git_zstream stream;
 248        unsigned char fakebuf[4096], *in;
 249        int st;
 250
 251        memset(&stream, 0, sizeof(stream));
 252        git_inflate_init(&stream);
 253        do {
 254                in = use_pack(p, w_curs, offset, &stream.avail_in);
 255                stream.next_in = in;
 256                stream.next_out = fakebuf;
 257                stream.avail_out = sizeof(fakebuf);
 258                st = git_inflate(&stream, Z_FINISH);
 259                offset += stream.next_in - in;
 260        } while (st == Z_OK || st == Z_BUF_ERROR);
 261        git_inflate_end(&stream);
 262        return (st == Z_STREAM_END &&
 263                stream.total_out == expect &&
 264                stream.total_in == len) ? 0 : -1;
 265}
 266
 267static void copy_pack_data(struct hashfile *f,
 268                struct packed_git *p,
 269                struct pack_window **w_curs,
 270                off_t offset,
 271                off_t len)
 272{
 273        unsigned char *in;
 274        unsigned long avail;
 275
 276        while (len) {
 277                in = use_pack(p, w_curs, offset, &avail);
 278                if (avail > len)
 279                        avail = (unsigned long)len;
 280                hashwrite(f, in, avail);
 281                offset += avail;
 282                len -= avail;
 283        }
 284}
 285
 286/* Return 0 if we will bust the pack-size limit */
 287static unsigned long write_no_reuse_object(struct hashfile *f, struct object_entry *entry,
 288                                           unsigned long limit, int usable_delta)
 289{
 290        unsigned long size, datalen;
 291        unsigned char header[MAX_PACK_OBJECT_HEADER],
 292                      dheader[MAX_PACK_OBJECT_HEADER];
 293        unsigned hdrlen;
 294        enum object_type type;
 295        void *buf;
 296        struct git_istream *st = NULL;
 297        const unsigned hashsz = the_hash_algo->rawsz;
 298
 299        if (!usable_delta) {
 300                if (oe_type(entry) == OBJ_BLOB &&
 301                    oe_size_greater_than(&to_pack, entry, big_file_threshold) &&
 302                    (st = open_istream(&entry->idx.oid, &type, &size, NULL)) != NULL)
 303                        buf = NULL;
 304                else {
 305                        buf = read_object_file(&entry->idx.oid, &type, &size);
 306                        if (!buf)
 307                                die(_("unable to read %s"),
 308                                    oid_to_hex(&entry->idx.oid));
 309                }
 310                /*
 311                 * make sure no cached delta data remains from a
 312                 * previous attempt before a pack split occurred.
 313                 */
 314                FREE_AND_NULL(entry->delta_data);
 315                entry->z_delta_size = 0;
 316        } else if (entry->delta_data) {
 317                size = DELTA_SIZE(entry);
 318                buf = entry->delta_data;
 319                entry->delta_data = NULL;
 320                type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 321                        OBJ_OFS_DELTA : OBJ_REF_DELTA;
 322        } else {
 323                buf = get_delta(entry);
 324                size = DELTA_SIZE(entry);
 325                type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 326                        OBJ_OFS_DELTA : OBJ_REF_DELTA;
 327        }
 328
 329        if (st) /* large blob case, just assume we don't compress well */
 330                datalen = size;
 331        else if (entry->z_delta_size)
 332                datalen = entry->z_delta_size;
 333        else
 334                datalen = do_compress(&buf, size);
 335
 336        /*
 337         * The object header is a byte of 'type' followed by zero or
 338         * more bytes of length.
 339         */
 340        hdrlen = encode_in_pack_object_header(header, sizeof(header),
 341                                              type, size);
 342
 343        if (type == OBJ_OFS_DELTA) {
 344                /*
 345                 * Deltas with relative base contain an additional
 346                 * encoding of the relative offset for the delta
 347                 * base from this object's position in the pack.
 348                 */
 349                off_t ofs = entry->idx.offset - DELTA(entry)->idx.offset;
 350                unsigned pos = sizeof(dheader) - 1;
 351                dheader[pos] = ofs & 127;
 352                while (ofs >>= 7)
 353                        dheader[--pos] = 128 | (--ofs & 127);
 354                if (limit && hdrlen + sizeof(dheader) - pos + datalen + hashsz >= limit) {
 355                        if (st)
 356                                close_istream(st);
 357                        free(buf);
 358                        return 0;
 359                }
 360                hashwrite(f, header, hdrlen);
 361                hashwrite(f, dheader + pos, sizeof(dheader) - pos);
 362                hdrlen += sizeof(dheader) - pos;
 363        } else if (type == OBJ_REF_DELTA) {
 364                /*
 365                 * Deltas with a base reference contain
 366                 * additional bytes for the base object ID.
 367                 */
 368                if (limit && hdrlen + hashsz + datalen + hashsz >= limit) {
 369                        if (st)
 370                                close_istream(st);
 371                        free(buf);
 372                        return 0;
 373                }
 374                hashwrite(f, header, hdrlen);
 375                hashwrite(f, DELTA(entry)->idx.oid.hash, hashsz);
 376                hdrlen += hashsz;
 377        } else {
 378                if (limit && hdrlen + datalen + hashsz >= limit) {
 379                        if (st)
 380                                close_istream(st);
 381                        free(buf);
 382                        return 0;
 383                }
 384                hashwrite(f, header, hdrlen);
 385        }
 386        if (st) {
 387                datalen = write_large_blob_data(st, f, &entry->idx.oid);
 388                close_istream(st);
 389        } else {
 390                hashwrite(f, buf, datalen);
 391                free(buf);
 392        }
 393
 394        return hdrlen + datalen;
 395}
 396
 397/* Return 0 if we will bust the pack-size limit */
 398static off_t write_reuse_object(struct hashfile *f, struct object_entry *entry,
 399                                unsigned long limit, int usable_delta)
 400{
 401        struct packed_git *p = IN_PACK(entry);
 402        struct pack_window *w_curs = NULL;
 403        struct revindex_entry *revidx;
 404        off_t offset;
 405        enum object_type type = oe_type(entry);
 406        off_t datalen;
 407        unsigned char header[MAX_PACK_OBJECT_HEADER],
 408                      dheader[MAX_PACK_OBJECT_HEADER];
 409        unsigned hdrlen;
 410        const unsigned hashsz = the_hash_algo->rawsz;
 411        unsigned long entry_size = SIZE(entry);
 412
 413        if (DELTA(entry))
 414                type = (allow_ofs_delta && DELTA(entry)->idx.offset) ?
 415                        OBJ_OFS_DELTA : OBJ_REF_DELTA;
 416        hdrlen = encode_in_pack_object_header(header, sizeof(header),
 417                                              type, entry_size);
 418
 419        offset = entry->in_pack_offset;
 420        revidx = find_pack_revindex(p, offset);
 421        datalen = revidx[1].offset - offset;
 422        if (!pack_to_stdout && p->index_version > 1 &&
 423            check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 424                error(_("bad packed object CRC for %s"),
 425                      oid_to_hex(&entry->idx.oid));
 426                unuse_pack(&w_curs);
 427                return write_no_reuse_object(f, entry, limit, usable_delta);
 428        }
 429
 430        offset += entry->in_pack_header_size;
 431        datalen -= entry->in_pack_header_size;
 432
 433        if (!pack_to_stdout && p->index_version == 1 &&
 434            check_pack_inflate(p, &w_curs, offset, datalen, entry_size)) {
 435                error(_("corrupt packed object for %s"),
 436                      oid_to_hex(&entry->idx.oid));
 437                unuse_pack(&w_curs);
 438                return write_no_reuse_object(f, entry, limit, usable_delta);
 439        }
 440
 441        if (type == OBJ_OFS_DELTA) {
 442                off_t ofs = entry->idx.offset - DELTA(entry)->idx.offset;
 443                unsigned pos = sizeof(dheader) - 1;
 444                dheader[pos] = ofs & 127;
 445                while (ofs >>= 7)
 446                        dheader[--pos] = 128 | (--ofs & 127);
 447                if (limit && hdrlen + sizeof(dheader) - pos + datalen + hashsz >= limit) {
 448                        unuse_pack(&w_curs);
 449                        return 0;
 450                }
 451                hashwrite(f, header, hdrlen);
 452                hashwrite(f, dheader + pos, sizeof(dheader) - pos);
 453                hdrlen += sizeof(dheader) - pos;
 454                reused_delta++;
 455        } else if (type == OBJ_REF_DELTA) {
 456                if (limit && hdrlen + hashsz + datalen + hashsz >= limit) {
 457                        unuse_pack(&w_curs);
 458                        return 0;
 459                }
 460                hashwrite(f, header, hdrlen);
 461                hashwrite(f, DELTA(entry)->idx.oid.hash, hashsz);
 462                hdrlen += hashsz;
 463                reused_delta++;
 464        } else {
 465                if (limit && hdrlen + datalen + hashsz >= limit) {
 466                        unuse_pack(&w_curs);
 467                        return 0;
 468                }
 469                hashwrite(f, header, hdrlen);
 470        }
 471        copy_pack_data(f, p, &w_curs, offset, datalen);
 472        unuse_pack(&w_curs);
 473        reused++;
 474        return hdrlen + datalen;
 475}
 476
 477/* Return 0 if we will bust the pack-size limit */
 478static off_t write_object(struct hashfile *f,
 479                          struct object_entry *entry,
 480                          off_t write_offset)
 481{
 482        unsigned long limit;
 483        off_t len;
 484        int usable_delta, to_reuse;
 485
 486        if (!pack_to_stdout)
 487                crc32_begin(f);
 488
 489        /* apply size limit if limited packsize and not first object */
 490        if (!pack_size_limit || !nr_written)
 491                limit = 0;
 492        else if (pack_size_limit <= write_offset)
 493                /*
 494                 * the earlier object did not fit the limit; avoid
 495                 * mistaking this with unlimited (i.e. limit = 0).
 496                 */
 497                limit = 1;
 498        else
 499                limit = pack_size_limit - write_offset;
 500
 501        if (!DELTA(entry))
 502                usable_delta = 0;       /* no delta */
 503        else if (!pack_size_limit)
 504               usable_delta = 1;        /* unlimited packfile */
 505        else if (DELTA(entry)->idx.offset == (off_t)-1)
 506                usable_delta = 0;       /* base was written to another pack */
 507        else if (DELTA(entry)->idx.offset)
 508                usable_delta = 1;       /* base already exists in this pack */
 509        else
 510                usable_delta = 0;       /* base could end up in another pack */
 511
 512        if (!reuse_object)
 513                to_reuse = 0;   /* explicit */
 514        else if (!IN_PACK(entry))
 515                to_reuse = 0;   /* can't reuse what we don't have */
 516        else if (oe_type(entry) == OBJ_REF_DELTA ||
 517                 oe_type(entry) == OBJ_OFS_DELTA)
 518                                /* check_object() decided it for us ... */
 519                to_reuse = usable_delta;
 520                                /* ... but pack split may override that */
 521        else if (oe_type(entry) != entry->in_pack_type)
 522                to_reuse = 0;   /* pack has delta which is unusable */
 523        else if (DELTA(entry))
 524                to_reuse = 0;   /* we want to pack afresh */
 525        else
 526                to_reuse = 1;   /* we have it in-pack undeltified,
 527                                 * and we do not need to deltify it.
 528                                 */
 529
 530        if (!to_reuse)
 531                len = write_no_reuse_object(f, entry, limit, usable_delta);
 532        else
 533                len = write_reuse_object(f, entry, limit, usable_delta);
 534        if (!len)
 535                return 0;
 536
 537        if (usable_delta)
 538                written_delta++;
 539        written++;
 540        if (!pack_to_stdout)
 541                entry->idx.crc32 = crc32_end(f);
 542        return len;
 543}
 544
 545enum write_one_status {
 546        WRITE_ONE_SKIP = -1, /* already written */
 547        WRITE_ONE_BREAK = 0, /* writing this will bust the limit; not written */
 548        WRITE_ONE_WRITTEN = 1, /* normal */
 549        WRITE_ONE_RECURSIVE = 2 /* already scheduled to be written */
 550};
 551
 552static enum write_one_status write_one(struct hashfile *f,
 553                                       struct object_entry *e,
 554                                       off_t *offset)
 555{
 556        off_t size;
 557        int recursing;
 558
 559        /*
 560         * we set offset to 1 (which is an impossible value) to mark
 561         * the fact that this object is involved in "write its base
 562         * first before writing a deltified object" recursion.
 563         */
 564        recursing = (e->idx.offset == 1);
 565        if (recursing) {
 566                warning(_("recursive delta detected for object %s"),
 567                        oid_to_hex(&e->idx.oid));
 568                return WRITE_ONE_RECURSIVE;
 569        } else if (e->idx.offset || e->preferred_base) {
 570                /* offset is non zero if object is written already. */
 571                return WRITE_ONE_SKIP;
 572        }
 573
 574        /* if we are deltified, write out base object first. */
 575        if (DELTA(e)) {
 576                e->idx.offset = 1; /* now recurse */
 577                switch (write_one(f, DELTA(e), offset)) {
 578                case WRITE_ONE_RECURSIVE:
 579                        /* we cannot depend on this one */
 580                        SET_DELTA(e, NULL);
 581                        break;
 582                default:
 583                        break;
 584                case WRITE_ONE_BREAK:
 585                        e->idx.offset = recursing;
 586                        return WRITE_ONE_BREAK;
 587                }
 588        }
 589
 590        e->idx.offset = *offset;
 591        size = write_object(f, e, *offset);
 592        if (!size) {
 593                e->idx.offset = recursing;
 594                return WRITE_ONE_BREAK;
 595        }
 596        written_list[nr_written++] = &e->idx;
 597
 598        /* make sure off_t is sufficiently large not to wrap */
 599        if (signed_add_overflows(*offset, size))
 600                die(_("pack too large for current definition of off_t"));
 601        *offset += size;
 602        return WRITE_ONE_WRITTEN;
 603}
 604
 605static int mark_tagged(const char *path, const struct object_id *oid, int flag,
 606                       void *cb_data)
 607{
 608        struct object_id peeled;
 609        struct object_entry *entry = packlist_find(&to_pack, oid, NULL);
 610
 611        if (entry)
 612                entry->tagged = 1;
 613        if (!peel_ref(path, &peeled)) {
 614                entry = packlist_find(&to_pack, &peeled, NULL);
 615                if (entry)
 616                        entry->tagged = 1;
 617        }
 618        return 0;
 619}
 620
 621static inline void add_to_write_order(struct object_entry **wo,
 622                               unsigned int *endp,
 623                               struct object_entry *e)
 624{
 625        if (e->filled || oe_layer(&to_pack, e) != write_layer)
 626                return;
 627        wo[(*endp)++] = e;
 628        e->filled = 1;
 629}
 630
 631static void add_descendants_to_write_order(struct object_entry **wo,
 632                                           unsigned int *endp,
 633                                           struct object_entry *e)
 634{
 635        int add_to_order = 1;
 636        while (e) {
 637                if (add_to_order) {
 638                        struct object_entry *s;
 639                        /* add this node... */
 640                        add_to_write_order(wo, endp, e);
 641                        /* all its siblings... */
 642                        for (s = DELTA_SIBLING(e); s; s = DELTA_SIBLING(s)) {
 643                                add_to_write_order(wo, endp, s);
 644                        }
 645                }
 646                /* drop down a level to add left subtree nodes if possible */
 647                if (DELTA_CHILD(e)) {
 648                        add_to_order = 1;
 649                        e = DELTA_CHILD(e);
 650                } else {
 651                        add_to_order = 0;
 652                        /* our sibling might have some children, it is next */
 653                        if (DELTA_SIBLING(e)) {
 654                                e = DELTA_SIBLING(e);
 655                                continue;
 656                        }
 657                        /* go back to our parent node */
 658                        e = DELTA(e);
 659                        while (e && !DELTA_SIBLING(e)) {
 660                                /* we're on the right side of a subtree, keep
 661                                 * going up until we can go right again */
 662                                e = DELTA(e);
 663                        }
 664                        if (!e) {
 665                                /* done- we hit our original root node */
 666                                return;
 667                        }
 668                        /* pass it off to sibling at this level */
 669                        e = DELTA_SIBLING(e);
 670                }
 671        };
 672}
 673
 674static void add_family_to_write_order(struct object_entry **wo,
 675                                      unsigned int *endp,
 676                                      struct object_entry *e)
 677{
 678        struct object_entry *root;
 679
 680        for (root = e; DELTA(root); root = DELTA(root))
 681                ; /* nothing */
 682        add_descendants_to_write_order(wo, endp, root);
 683}
 684
 685static void compute_layer_order(struct object_entry **wo, unsigned int *wo_end)
 686{
 687        unsigned int i, last_untagged;
 688        struct object_entry *objects = to_pack.objects;
 689
 690        for (i = 0; i < to_pack.nr_objects; i++) {
 691                if (objects[i].tagged)
 692                        break;
 693                add_to_write_order(wo, wo_end, &objects[i]);
 694        }
 695        last_untagged = i;
 696
 697        /*
 698         * Then fill all the tagged tips.
 699         */
 700        for (; i < to_pack.nr_objects; i++) {
 701                if (objects[i].tagged)
 702                        add_to_write_order(wo, wo_end, &objects[i]);
 703        }
 704
 705        /*
 706         * And then all remaining commits and tags.
 707         */
 708        for (i = last_untagged; i < to_pack.nr_objects; i++) {
 709                if (oe_type(&objects[i]) != OBJ_COMMIT &&
 710                    oe_type(&objects[i]) != OBJ_TAG)
 711                        continue;
 712                add_to_write_order(wo, wo_end, &objects[i]);
 713        }
 714
 715        /*
 716         * And then all the trees.
 717         */
 718        for (i = last_untagged; i < to_pack.nr_objects; i++) {
 719                if (oe_type(&objects[i]) != OBJ_TREE)
 720                        continue;
 721                add_to_write_order(wo, wo_end, &objects[i]);
 722        }
 723
 724        /*
 725         * Finally all the rest in really tight order
 726         */
 727        for (i = last_untagged; i < to_pack.nr_objects; i++) {
 728                if (!objects[i].filled && oe_layer(&to_pack, &objects[i]) == write_layer)
 729                        add_family_to_write_order(wo, wo_end, &objects[i]);
 730        }
 731}
 732
 733static struct object_entry **compute_write_order(void)
 734{
 735        uint32_t max_layers = 1;
 736        unsigned int i, wo_end;
 737
 738        struct object_entry **wo;
 739        struct object_entry *objects = to_pack.objects;
 740
 741        for (i = 0; i < to_pack.nr_objects; i++) {
 742                objects[i].tagged = 0;
 743                objects[i].filled = 0;
 744                SET_DELTA_CHILD(&objects[i], NULL);
 745                SET_DELTA_SIBLING(&objects[i], NULL);
 746        }
 747
 748        /*
 749         * Fully connect delta_child/delta_sibling network.
 750         * Make sure delta_sibling is sorted in the original
 751         * recency order.
 752         */
 753        for (i = to_pack.nr_objects; i > 0;) {
 754                struct object_entry *e = &objects[--i];
 755                if (!DELTA(e))
 756                        continue;
 757                /* Mark me as the first child */
 758                e->delta_sibling_idx = DELTA(e)->delta_child_idx;
 759                SET_DELTA_CHILD(DELTA(e), e);
 760        }
 761
 762        /*
 763         * Mark objects that are at the tip of tags.
 764         */
 765        for_each_tag_ref(mark_tagged, NULL);
 766
 767        if (use_delta_islands)
 768                max_layers = compute_pack_layers(&to_pack);
 769
 770        ALLOC_ARRAY(wo, to_pack.nr_objects);
 771        wo_end = 0;
 772
 773        for (; write_layer < max_layers; ++write_layer)
 774                compute_layer_order(wo, &wo_end);
 775
 776        if (wo_end != to_pack.nr_objects)
 777                die(_("ordered %u objects, expected %"PRIu32),
 778                    wo_end, to_pack.nr_objects);
 779
 780        return wo;
 781}
 782
 783static off_t write_reused_pack(struct hashfile *f)
 784{
 785        unsigned char buffer[8192];
 786        off_t to_write, total;
 787        int fd;
 788
 789        if (!is_pack_valid(reuse_packfile))
 790                die(_("packfile is invalid: %s"), reuse_packfile->pack_name);
 791
 792        fd = git_open(reuse_packfile->pack_name);
 793        if (fd < 0)
 794                die_errno(_("unable to open packfile for reuse: %s"),
 795                          reuse_packfile->pack_name);
 796
 797        if (lseek(fd, sizeof(struct pack_header), SEEK_SET) == -1)
 798                die_errno(_("unable to seek in reused packfile"));
 799
 800        if (reuse_packfile_offset < 0)
 801                reuse_packfile_offset = reuse_packfile->pack_size - the_hash_algo->rawsz;
 802
 803        total = to_write = reuse_packfile_offset - sizeof(struct pack_header);
 804
 805        while (to_write) {
 806                int read_pack = xread(fd, buffer, sizeof(buffer));
 807
 808                if (read_pack <= 0)
 809                        die_errno(_("unable to read from reused packfile"));
 810
 811                if (read_pack > to_write)
 812                        read_pack = to_write;
 813
 814                hashwrite(f, buffer, read_pack);
 815                to_write -= read_pack;
 816
 817                /*
 818                 * We don't know the actual number of objects written,
 819                 * only how many bytes written, how many bytes total, and
 820                 * how many objects total. So we can fake it by pretending all
 821                 * objects we are writing are the same size. This gives us a
 822                 * smooth progress meter, and at the end it matches the true
 823                 * answer.
 824                 */
 825                written = reuse_packfile_objects *
 826                                (((double)(total - to_write)) / total);
 827                display_progress(progress_state, written);
 828        }
 829
 830        close(fd);
 831        written = reuse_packfile_objects;
 832        display_progress(progress_state, written);
 833        return reuse_packfile_offset - sizeof(struct pack_header);
 834}
 835
 836static const char no_split_warning[] = N_(
 837"disabling bitmap writing, packs are split due to pack.packSizeLimit"
 838);
 839
 840static void write_pack_file(void)
 841{
 842        uint32_t i = 0, j;
 843        struct hashfile *f;
 844        off_t offset;
 845        uint32_t nr_remaining = nr_result;
 846        time_t last_mtime = 0;
 847        struct object_entry **write_order;
 848
 849        if (progress > pack_to_stdout)
 850                progress_state = start_progress(_("Writing objects"), nr_result);
 851        ALLOC_ARRAY(written_list, to_pack.nr_objects);
 852        write_order = compute_write_order();
 853
 854        do {
 855                struct object_id oid;
 856                char *pack_tmp_name = NULL;
 857
 858                if (pack_to_stdout)
 859                        f = hashfd_throughput(1, "<stdout>", progress_state);
 860                else
 861                        f = create_tmp_packfile(&pack_tmp_name);
 862
 863                offset = write_pack_header(f, nr_remaining);
 864
 865                if (reuse_packfile) {
 866                        off_t packfile_size;
 867                        assert(pack_to_stdout);
 868
 869                        packfile_size = write_reused_pack(f);
 870                        offset += packfile_size;
 871                }
 872
 873                nr_written = 0;
 874                for (; i < to_pack.nr_objects; i++) {
 875                        struct object_entry *e = write_order[i];
 876                        if (write_one(f, e, &offset) == WRITE_ONE_BREAK)
 877                                break;
 878                        display_progress(progress_state, written);
 879                }
 880
 881                /*
 882                 * Did we write the wrong # entries in the header?
 883                 * If so, rewrite it like in fast-import
 884                 */
 885                if (pack_to_stdout) {
 886                        finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_CLOSE);
 887                } else if (nr_written == nr_remaining) {
 888                        finalize_hashfile(f, oid.hash, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
 889                } else {
 890                        int fd = finalize_hashfile(f, oid.hash, 0);
 891                        fixup_pack_header_footer(fd, oid.hash, pack_tmp_name,
 892                                                 nr_written, oid.hash, offset);
 893                        close(fd);
 894                        if (write_bitmap_index) {
 895                                warning(_(no_split_warning));
 896                                write_bitmap_index = 0;
 897                        }
 898                }
 899
 900                if (!pack_to_stdout) {
 901                        struct stat st;
 902                        struct strbuf tmpname = STRBUF_INIT;
 903
 904                        /*
 905                         * Packs are runtime accessed in their mtime
 906                         * order since newer packs are more likely to contain
 907                         * younger objects.  So if we are creating multiple
 908                         * packs then we should modify the mtime of later ones
 909                         * to preserve this property.
 910                         */
 911                        if (stat(pack_tmp_name, &st) < 0) {
 912                                warning_errno(_("failed to stat %s"), pack_tmp_name);
 913                        } else if (!last_mtime) {
 914                                last_mtime = st.st_mtime;
 915                        } else {
 916                                struct utimbuf utb;
 917                                utb.actime = st.st_atime;
 918                                utb.modtime = --last_mtime;
 919                                if (utime(pack_tmp_name, &utb) < 0)
 920                                        warning_errno(_("failed utime() on %s"), pack_tmp_name);
 921                        }
 922
 923                        strbuf_addf(&tmpname, "%s-", base_name);
 924
 925                        if (write_bitmap_index) {
 926                                bitmap_writer_set_checksum(oid.hash);
 927                                bitmap_writer_build_type_index(
 928                                        &to_pack, written_list, nr_written);
 929                        }
 930
 931                        finish_tmp_packfile(&tmpname, pack_tmp_name,
 932                                            written_list, nr_written,
 933                                            &pack_idx_opts, oid.hash);
 934
 935                        if (write_bitmap_index) {
 936                                strbuf_addf(&tmpname, "%s.bitmap", oid_to_hex(&oid));
 937
 938                                stop_progress(&progress_state);
 939
 940                                bitmap_writer_show_progress(progress);
 941                                bitmap_writer_reuse_bitmaps(&to_pack);
 942                                bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
 943                                bitmap_writer_build(&to_pack);
 944                                bitmap_writer_finish(written_list, nr_written,
 945                                                     tmpname.buf, write_bitmap_options);
 946                                write_bitmap_index = 0;
 947                        }
 948
 949                        strbuf_release(&tmpname);
 950                        free(pack_tmp_name);
 951                        puts(oid_to_hex(&oid));
 952                }
 953
 954                /* mark written objects as written to previous pack */
 955                for (j = 0; j < nr_written; j++) {
 956                        written_list[j]->offset = (off_t)-1;
 957                }
 958                nr_remaining -= nr_written;
 959        } while (nr_remaining && i < to_pack.nr_objects);
 960
 961        free(written_list);
 962        free(write_order);
 963        stop_progress(&progress_state);
 964        if (written != nr_result)
 965                die(_("wrote %"PRIu32" objects while expecting %"PRIu32),
 966                    written, nr_result);
 967        trace2_data_intmax("pack-objects", the_repository,
 968                           "write_pack_file/wrote", nr_result);
 969}
 970
 971static int no_try_delta(const char *path)
 972{
 973        static struct attr_check *check;
 974
 975        if (!check)
 976                check = attr_check_initl("delta", NULL);
 977        git_check_attr(the_repository->index, path, check);
 978        if (ATTR_FALSE(check->items[0].value))
 979                return 1;
 980        return 0;
 981}
 982
 983/*
 984 * When adding an object, check whether we have already added it
 985 * to our packing list. If so, we can skip. However, if we are
 986 * being asked to excludei t, but the previous mention was to include
 987 * it, make sure to adjust its flags and tweak our numbers accordingly.
 988 *
 989 * As an optimization, we pass out the index position where we would have
 990 * found the item, since that saves us from having to look it up again a
 991 * few lines later when we want to add the new entry.
 992 */
 993static int have_duplicate_entry(const struct object_id *oid,
 994                                int exclude,
 995                                uint32_t *index_pos)
 996{
 997        struct object_entry *entry;
 998
 999        entry = packlist_find(&to_pack, oid, index_pos);
1000        if (!entry)
1001                return 0;
1002
1003        if (exclude) {
1004                if (!entry->preferred_base)
1005                        nr_result--;
1006                entry->preferred_base = 1;
1007        }
1008
1009        return 1;
1010}
1011
1012static int want_found_object(int exclude, struct packed_git *p)
1013{
1014        if (exclude)
1015                return 1;
1016        if (incremental)
1017                return 0;
1018
1019        /*
1020         * When asked to do --local (do not include an object that appears in a
1021         * pack we borrow from elsewhere) or --honor-pack-keep (do not include
1022         * an object that appears in a pack marked with .keep), finding a pack
1023         * that matches the criteria is sufficient for us to decide to omit it.
1024         * However, even if this pack does not satisfy the criteria, we need to
1025         * make sure no copy of this object appears in _any_ pack that makes us
1026         * to omit the object, so we need to check all the packs.
1027         *
1028         * We can however first check whether these options can possible matter;
1029         * if they do not matter we know we want the object in generated pack.
1030         * Otherwise, we signal "-1" at the end to tell the caller that we do
1031         * not know either way, and it needs to check more packs.
1032         */
1033        if (!ignore_packed_keep_on_disk &&
1034            !ignore_packed_keep_in_core &&
1035            (!local || !have_non_local_packs))
1036                return 1;
1037
1038        if (local && !p->pack_local)
1039                return 0;
1040        if (p->pack_local &&
1041            ((ignore_packed_keep_on_disk && p->pack_keep) ||
1042             (ignore_packed_keep_in_core && p->pack_keep_in_core)))
1043                return 0;
1044
1045        /* we don't know yet; keep looking for more packs */
1046        return -1;
1047}
1048
1049/*
1050 * Check whether we want the object in the pack (e.g., we do not want
1051 * objects found in non-local stores if the "--local" option was used).
1052 *
1053 * If the caller already knows an existing pack it wants to take the object
1054 * from, that is passed in *found_pack and *found_offset; otherwise this
1055 * function finds if there is any pack that has the object and returns the pack
1056 * and its offset in these variables.
1057 */
1058static int want_object_in_pack(const struct object_id *oid,
1059                               int exclude,
1060                               struct packed_git **found_pack,
1061                               off_t *found_offset)
1062{
1063        int want;
1064        struct list_head *pos;
1065        struct multi_pack_index *m;
1066
1067        if (!exclude && local && has_loose_object_nonlocal(oid))
1068                return 0;
1069
1070        /*
1071         * If we already know the pack object lives in, start checks from that
1072         * pack - in the usual case when neither --local was given nor .keep files
1073         * are present we will determine the answer right now.
1074         */
1075        if (*found_pack) {
1076                want = want_found_object(exclude, *found_pack);
1077                if (want != -1)
1078                        return want;
1079        }
1080
1081        for (m = get_multi_pack_index(the_repository); m; m = m->next) {
1082                struct pack_entry e;
1083                if (fill_midx_entry(the_repository, oid, &e, m)) {
1084                        struct packed_git *p = e.p;
1085                        off_t offset;
1086
1087                        if (p == *found_pack)
1088                                offset = *found_offset;
1089                        else
1090                                offset = find_pack_entry_one(oid->hash, p);
1091
1092                        if (offset) {
1093                                if (!*found_pack) {
1094                                        if (!is_pack_valid(p))
1095                                                continue;
1096                                        *found_offset = offset;
1097                                        *found_pack = p;
1098                                }
1099                                want = want_found_object(exclude, p);
1100                                if (want != -1)
1101                                        return want;
1102                        }
1103                }
1104        }
1105
1106        list_for_each(pos, get_packed_git_mru(the_repository)) {
1107                struct packed_git *p = list_entry(pos, struct packed_git, mru);
1108                off_t offset;
1109
1110                if (p == *found_pack)
1111                        offset = *found_offset;
1112                else
1113                        offset = find_pack_entry_one(oid->hash, p);
1114
1115                if (offset) {
1116                        if (!*found_pack) {
1117                                if (!is_pack_valid(p))
1118                                        continue;
1119                                *found_offset = offset;
1120                                *found_pack = p;
1121                        }
1122                        want = want_found_object(exclude, p);
1123                        if (!exclude && want > 0)
1124                                list_move(&p->mru,
1125                                          get_packed_git_mru(the_repository));
1126                        if (want != -1)
1127                                return want;
1128                }
1129        }
1130
1131        return 1;
1132}
1133
1134static void create_object_entry(const struct object_id *oid,
1135                                enum object_type type,
1136                                uint32_t hash,
1137                                int exclude,
1138                                int no_try_delta,
1139                                uint32_t index_pos,
1140                                struct packed_git *found_pack,
1141                                off_t found_offset)
1142{
1143        struct object_entry *entry;
1144
1145        entry = packlist_alloc(&to_pack, oid->hash, index_pos);
1146        entry->hash = hash;
1147        oe_set_type(entry, type);
1148        if (exclude)
1149                entry->preferred_base = 1;
1150        else
1151                nr_result++;
1152        if (found_pack) {
1153                oe_set_in_pack(&to_pack, entry, found_pack);
1154                entry->in_pack_offset = found_offset;
1155        }
1156
1157        entry->no_try_delta = no_try_delta;
1158}
1159
1160static const char no_closure_warning[] = N_(
1161"disabling bitmap writing, as some objects are not being packed"
1162);
1163
1164static int add_object_entry(const struct object_id *oid, enum object_type type,
1165                            const char *name, int exclude)
1166{
1167        struct packed_git *found_pack = NULL;
1168        off_t found_offset = 0;
1169        uint32_t index_pos;
1170
1171        display_progress(progress_state, ++nr_seen);
1172
1173        if (have_duplicate_entry(oid, exclude, &index_pos))
1174                return 0;
1175
1176        if (!want_object_in_pack(oid, exclude, &found_pack, &found_offset)) {
1177                /* The pack is missing an object, so it will not have closure */
1178                if (write_bitmap_index) {
1179                        warning(_(no_closure_warning));
1180                        write_bitmap_index = 0;
1181                }
1182                return 0;
1183        }
1184
1185        create_object_entry(oid, type, pack_name_hash(name),
1186                            exclude, name && no_try_delta(name),
1187                            index_pos, found_pack, found_offset);
1188        return 1;
1189}
1190
1191static int add_object_entry_from_bitmap(const struct object_id *oid,
1192                                        enum object_type type,
1193                                        int flags, uint32_t name_hash,
1194                                        struct packed_git *pack, off_t offset)
1195{
1196        uint32_t index_pos;
1197
1198        display_progress(progress_state, ++nr_seen);
1199
1200        if (have_duplicate_entry(oid, 0, &index_pos))
1201                return 0;
1202
1203        if (!want_object_in_pack(oid, 0, &pack, &offset))
1204                return 0;
1205
1206        create_object_entry(oid, type, name_hash, 0, 0, index_pos, pack, offset);
1207        return 1;
1208}
1209
1210struct pbase_tree_cache {
1211        struct object_id oid;
1212        int ref;
1213        int temporary;
1214        void *tree_data;
1215        unsigned long tree_size;
1216};
1217
1218static struct pbase_tree_cache *(pbase_tree_cache[256]);
1219static int pbase_tree_cache_ix(const struct object_id *oid)
1220{
1221        return oid->hash[0] % ARRAY_SIZE(pbase_tree_cache);
1222}
1223static int pbase_tree_cache_ix_incr(int ix)
1224{
1225        return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
1226}
1227
1228static struct pbase_tree {
1229        struct pbase_tree *next;
1230        /* This is a phony "cache" entry; we are not
1231         * going to evict it or find it through _get()
1232         * mechanism -- this is for the toplevel node that
1233         * would almost always change with any commit.
1234         */
1235        struct pbase_tree_cache pcache;
1236} *pbase_tree;
1237
1238static struct pbase_tree_cache *pbase_tree_get(const struct object_id *oid)
1239{
1240        struct pbase_tree_cache *ent, *nent;
1241        void *data;
1242        unsigned long size;
1243        enum object_type type;
1244        int neigh;
1245        int my_ix = pbase_tree_cache_ix(oid);
1246        int available_ix = -1;
1247
1248        /* pbase-tree-cache acts as a limited hashtable.
1249         * your object will be found at your index or within a few
1250         * slots after that slot if it is cached.
1251         */
1252        for (neigh = 0; neigh < 8; neigh++) {
1253                ent = pbase_tree_cache[my_ix];
1254                if (ent && oideq(&ent->oid, oid)) {
1255                        ent->ref++;
1256                        return ent;
1257                }
1258                else if (((available_ix < 0) && (!ent || !ent->ref)) ||
1259                         ((0 <= available_ix) &&
1260                          (!ent && pbase_tree_cache[available_ix])))
1261                        available_ix = my_ix;
1262                if (!ent)
1263                        break;
1264                my_ix = pbase_tree_cache_ix_incr(my_ix);
1265        }
1266
1267        /* Did not find one.  Either we got a bogus request or
1268         * we need to read and perhaps cache.
1269         */
1270        data = read_object_file(oid, &type, &size);
1271        if (!data)
1272                return NULL;
1273        if (type != OBJ_TREE) {
1274                free(data);
1275                return NULL;
1276        }
1277
1278        /* We need to either cache or return a throwaway copy */
1279
1280        if (available_ix < 0)
1281                ent = NULL;
1282        else {
1283                ent = pbase_tree_cache[available_ix];
1284                my_ix = available_ix;
1285        }
1286
1287        if (!ent) {
1288                nent = xmalloc(sizeof(*nent));
1289                nent->temporary = (available_ix < 0);
1290        }
1291        else {
1292                /* evict and reuse */
1293                free(ent->tree_data);
1294                nent = ent;
1295        }
1296        oidcpy(&nent->oid, oid);
1297        nent->tree_data = data;
1298        nent->tree_size = size;
1299        nent->ref = 1;
1300        if (!nent->temporary)
1301                pbase_tree_cache[my_ix] = nent;
1302        return nent;
1303}
1304
1305static void pbase_tree_put(struct pbase_tree_cache *cache)
1306{
1307        if (!cache->temporary) {
1308                cache->ref--;
1309                return;
1310        }
1311        free(cache->tree_data);
1312        free(cache);
1313}
1314
1315static int name_cmp_len(const char *name)
1316{
1317        int i;
1318        for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
1319                ;
1320        return i;
1321}
1322
1323static void add_pbase_object(struct tree_desc *tree,
1324                             const char *name,
1325                             int cmplen,
1326                             const char *fullname)
1327{
1328        struct name_entry entry;
1329        int cmp;
1330
1331        while (tree_entry(tree,&entry)) {
1332                if (S_ISGITLINK(entry.mode))
1333                        continue;
1334                cmp = tree_entry_len(&entry) != cmplen ? 1 :
1335                      memcmp(name, entry.path, cmplen);
1336                if (cmp > 0)
1337                        continue;
1338                if (cmp < 0)
1339                        return;
1340                if (name[cmplen] != '/') {
1341                        add_object_entry(&entry.oid,
1342                                         object_type(entry.mode),
1343                                         fullname, 1);
1344                        return;
1345                }
1346                if (S_ISDIR(entry.mode)) {
1347                        struct tree_desc sub;
1348                        struct pbase_tree_cache *tree;
1349                        const char *down = name+cmplen+1;
1350                        int downlen = name_cmp_len(down);
1351
1352                        tree = pbase_tree_get(&entry.oid);
1353                        if (!tree)
1354                                return;
1355                        init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1356
1357                        add_pbase_object(&sub, down, downlen, fullname);
1358                        pbase_tree_put(tree);
1359                }
1360        }
1361}
1362
1363static unsigned *done_pbase_paths;
1364static int done_pbase_paths_num;
1365static int done_pbase_paths_alloc;
1366static int done_pbase_path_pos(unsigned hash)
1367{
1368        int lo = 0;
1369        int hi = done_pbase_paths_num;
1370        while (lo < hi) {
1371                int mi = lo + (hi - lo) / 2;
1372                if (done_pbase_paths[mi] == hash)
1373                        return mi;
1374                if (done_pbase_paths[mi] < hash)
1375                        hi = mi;
1376                else
1377                        lo = mi + 1;
1378        }
1379        return -lo-1;
1380}
1381
1382static int check_pbase_path(unsigned hash)
1383{
1384        int pos = done_pbase_path_pos(hash);
1385        if (0 <= pos)
1386                return 1;
1387        pos = -pos - 1;
1388        ALLOC_GROW(done_pbase_paths,
1389                   done_pbase_paths_num + 1,
1390                   done_pbase_paths_alloc);
1391        done_pbase_paths_num++;
1392        if (pos < done_pbase_paths_num)
1393                MOVE_ARRAY(done_pbase_paths + pos + 1, done_pbase_paths + pos,
1394                           done_pbase_paths_num - pos - 1);
1395        done_pbase_paths[pos] = hash;
1396        return 0;
1397}
1398
1399static void add_preferred_base_object(const char *name)
1400{
1401        struct pbase_tree *it;
1402        int cmplen;
1403        unsigned hash = pack_name_hash(name);
1404
1405        if (!num_preferred_base || check_pbase_path(hash))
1406                return;
1407
1408        cmplen = name_cmp_len(name);
1409        for (it = pbase_tree; it; it = it->next) {
1410                if (cmplen == 0) {
1411                        add_object_entry(&it->pcache.oid, OBJ_TREE, NULL, 1);
1412                }
1413                else {
1414                        struct tree_desc tree;
1415                        init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1416                        add_pbase_object(&tree, name, cmplen, name);
1417                }
1418        }
1419}
1420
1421static void add_preferred_base(struct object_id *oid)
1422{
1423        struct pbase_tree *it;
1424        void *data;
1425        unsigned long size;
1426        struct object_id tree_oid;
1427
1428        if (window <= num_preferred_base++)
1429                return;
1430
1431        data = read_object_with_reference(the_repository, oid,
1432                                          tree_type, &size, &tree_oid);
1433        if (!data)
1434                return;
1435
1436        for (it = pbase_tree; it; it = it->next) {
1437                if (oideq(&it->pcache.oid, &tree_oid)) {
1438                        free(data);
1439                        return;
1440                }
1441        }
1442
1443        it = xcalloc(1, sizeof(*it));
1444        it->next = pbase_tree;
1445        pbase_tree = it;
1446
1447        oidcpy(&it->pcache.oid, &tree_oid);
1448        it->pcache.tree_data = data;
1449        it->pcache.tree_size = size;
1450}
1451
1452static void cleanup_preferred_base(void)
1453{
1454        struct pbase_tree *it;
1455        unsigned i;
1456
1457        it = pbase_tree;
1458        pbase_tree = NULL;
1459        while (it) {
1460                struct pbase_tree *tmp = it;
1461                it = tmp->next;
1462                free(tmp->pcache.tree_data);
1463                free(tmp);
1464        }
1465
1466        for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1467                if (!pbase_tree_cache[i])
1468                        continue;
1469                free(pbase_tree_cache[i]->tree_data);
1470                FREE_AND_NULL(pbase_tree_cache[i]);
1471        }
1472
1473        FREE_AND_NULL(done_pbase_paths);
1474        done_pbase_paths_num = done_pbase_paths_alloc = 0;
1475}
1476
1477/*
1478 * Return 1 iff the object specified by "delta" can be sent
1479 * literally as a delta against the base in "base_sha1". If
1480 * so, then *base_out will point to the entry in our packing
1481 * list, or NULL if we must use the external-base list.
1482 *
1483 * Depth value does not matter - find_deltas() will
1484 * never consider reused delta as the base object to
1485 * deltify other objects against, in order to avoid
1486 * circular deltas.
1487 */
1488static int can_reuse_delta(const unsigned char *base_sha1,
1489                           struct object_entry *delta,
1490                           struct object_entry **base_out)
1491{
1492        struct object_entry *base;
1493        struct object_id base_oid;
1494
1495        if (!base_sha1)
1496                return 0;
1497
1498        oidread(&base_oid, base_sha1);
1499
1500        /*
1501         * First see if we're already sending the base (or it's explicitly in
1502         * our "excluded" list).
1503         */
1504        base = packlist_find(&to_pack, &base_oid, NULL);
1505        if (base) {
1506                if (!in_same_island(&delta->idx.oid, &base->idx.oid))
1507                        return 0;
1508                *base_out = base;
1509                return 1;
1510        }
1511
1512        /*
1513         * Otherwise, reachability bitmaps may tell us if the receiver has it,
1514         * even if it was buried too deep in history to make it into the
1515         * packing list.
1516         */
1517        if (thin && bitmap_has_oid_in_uninteresting(bitmap_git, &base_oid)) {
1518                if (use_delta_islands) {
1519                        if (!in_same_island(&delta->idx.oid, &base_oid))
1520                                return 0;
1521                }
1522                *base_out = NULL;
1523                return 1;
1524        }
1525
1526        return 0;
1527}
1528
1529static void check_object(struct object_entry *entry)
1530{
1531        unsigned long canonical_size;
1532
1533        if (IN_PACK(entry)) {
1534                struct packed_git *p = IN_PACK(entry);
1535                struct pack_window *w_curs = NULL;
1536                const unsigned char *base_ref = NULL;
1537                struct object_entry *base_entry;
1538                unsigned long used, used_0;
1539                unsigned long avail;
1540                off_t ofs;
1541                unsigned char *buf, c;
1542                enum object_type type;
1543                unsigned long in_pack_size;
1544
1545                buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1546
1547                /*
1548                 * We want in_pack_type even if we do not reuse delta
1549                 * since non-delta representations could still be reused.
1550                 */
1551                used = unpack_object_header_buffer(buf, avail,
1552                                                   &type,
1553                                                   &in_pack_size);
1554                if (used == 0)
1555                        goto give_up;
1556
1557                if (type < 0)
1558                        BUG("invalid type %d", type);
1559                entry->in_pack_type = type;
1560
1561                /*
1562                 * Determine if this is a delta and if so whether we can
1563                 * reuse it or not.  Otherwise let's find out as cheaply as
1564                 * possible what the actual type and size for this object is.
1565                 */
1566                switch (entry->in_pack_type) {
1567                default:
1568                        /* Not a delta hence we've already got all we need. */
1569                        oe_set_type(entry, entry->in_pack_type);
1570                        SET_SIZE(entry, in_pack_size);
1571                        entry->in_pack_header_size = used;
1572                        if (oe_type(entry) < OBJ_COMMIT || oe_type(entry) > OBJ_BLOB)
1573                                goto give_up;
1574                        unuse_pack(&w_curs);
1575                        return;
1576                case OBJ_REF_DELTA:
1577                        if (reuse_delta && !entry->preferred_base)
1578                                base_ref = use_pack(p, &w_curs,
1579                                                entry->in_pack_offset + used, NULL);
1580                        entry->in_pack_header_size = used + the_hash_algo->rawsz;
1581                        break;
1582                case OBJ_OFS_DELTA:
1583                        buf = use_pack(p, &w_curs,
1584                                       entry->in_pack_offset + used, NULL);
1585                        used_0 = 0;
1586                        c = buf[used_0++];
1587                        ofs = c & 127;
1588                        while (c & 128) {
1589                                ofs += 1;
1590                                if (!ofs || MSB(ofs, 7)) {
1591                                        error(_("delta base offset overflow in pack for %s"),
1592                                              oid_to_hex(&entry->idx.oid));
1593                                        goto give_up;
1594                                }
1595                                c = buf[used_0++];
1596                                ofs = (ofs << 7) + (c & 127);
1597                        }
1598                        ofs = entry->in_pack_offset - ofs;
1599                        if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1600                                error(_("delta base offset out of bound for %s"),
1601                                      oid_to_hex(&entry->idx.oid));
1602                                goto give_up;
1603                        }
1604                        if (reuse_delta && !entry->preferred_base) {
1605                                struct revindex_entry *revidx;
1606                                revidx = find_pack_revindex(p, ofs);
1607                                if (!revidx)
1608                                        goto give_up;
1609                                base_ref = nth_packed_object_sha1(p, revidx->nr);
1610                        }
1611                        entry->in_pack_header_size = used + used_0;
1612                        break;
1613                }
1614
1615                if (can_reuse_delta(base_ref, entry, &base_entry)) {
1616                        oe_set_type(entry, entry->in_pack_type);
1617                        SET_SIZE(entry, in_pack_size); /* delta size */
1618                        SET_DELTA_SIZE(entry, in_pack_size);
1619
1620                        if (base_entry) {
1621                                SET_DELTA(entry, base_entry);
1622                                entry->delta_sibling_idx = base_entry->delta_child_idx;
1623                                SET_DELTA_CHILD(base_entry, entry);
1624                        } else {
1625                                SET_DELTA_EXT(entry, base_ref);
1626                        }
1627
1628                        unuse_pack(&w_curs);
1629                        return;
1630                }
1631
1632                if (oe_type(entry)) {
1633                        off_t delta_pos;
1634
1635                        /*
1636                         * This must be a delta and we already know what the
1637                         * final object type is.  Let's extract the actual
1638                         * object size from the delta header.
1639                         */
1640                        delta_pos = entry->in_pack_offset + entry->in_pack_header_size;
1641                        canonical_size = get_size_from_delta(p, &w_curs, delta_pos);
1642                        if (canonical_size == 0)
1643                                goto give_up;
1644                        SET_SIZE(entry, canonical_size);
1645                        unuse_pack(&w_curs);
1646                        return;
1647                }
1648
1649                /*
1650                 * No choice but to fall back to the recursive delta walk
1651                 * with oid_object_info() to find about the object type
1652                 * at this point...
1653                 */
1654                give_up:
1655                unuse_pack(&w_curs);
1656        }
1657
1658        oe_set_type(entry,
1659                    oid_object_info(the_repository, &entry->idx.oid, &canonical_size));
1660        if (entry->type_valid) {
1661                SET_SIZE(entry, canonical_size);
1662        } else {
1663                /*
1664                 * Bad object type is checked in prepare_pack().  This is
1665                 * to permit a missing preferred base object to be ignored
1666                 * as a preferred base.  Doing so can result in a larger
1667                 * pack file, but the transfer will still take place.
1668                 */
1669        }
1670}
1671
1672static int pack_offset_sort(const void *_a, const void *_b)
1673{
1674        const struct object_entry *a = *(struct object_entry **)_a;
1675        const struct object_entry *b = *(struct object_entry **)_b;
1676        const struct packed_git *a_in_pack = IN_PACK(a);
1677        const struct packed_git *b_in_pack = IN_PACK(b);
1678
1679        /* avoid filesystem trashing with loose objects */
1680        if (!a_in_pack && !b_in_pack)
1681                return oidcmp(&a->idx.oid, &b->idx.oid);
1682
1683        if (a_in_pack < b_in_pack)
1684                return -1;
1685        if (a_in_pack > b_in_pack)
1686                return 1;
1687        return a->in_pack_offset < b->in_pack_offset ? -1 :
1688                        (a->in_pack_offset > b->in_pack_offset);
1689}
1690
1691/*
1692 * Drop an on-disk delta we were planning to reuse. Naively, this would
1693 * just involve blanking out the "delta" field, but we have to deal
1694 * with some extra book-keeping:
1695 *
1696 *   1. Removing ourselves from the delta_sibling linked list.
1697 *
1698 *   2. Updating our size/type to the non-delta representation. These were
1699 *      either not recorded initially (size) or overwritten with the delta type
1700 *      (type) when check_object() decided to reuse the delta.
1701 *
1702 *   3. Resetting our delta depth, as we are now a base object.
1703 */
1704static void drop_reused_delta(struct object_entry *entry)
1705{
1706        unsigned *idx = &to_pack.objects[entry->delta_idx - 1].delta_child_idx;
1707        struct object_info oi = OBJECT_INFO_INIT;
1708        enum object_type type;
1709        unsigned long size;
1710
1711        while (*idx) {
1712                struct object_entry *oe = &to_pack.objects[*idx - 1];
1713
1714                if (oe == entry)
1715                        *idx = oe->delta_sibling_idx;
1716                else
1717                        idx = &oe->delta_sibling_idx;
1718        }
1719        SET_DELTA(entry, NULL);
1720        entry->depth = 0;
1721
1722        oi.sizep = &size;
1723        oi.typep = &type;
1724        if (packed_object_info(the_repository, IN_PACK(entry), entry->in_pack_offset, &oi) < 0) {
1725                /*
1726                 * We failed to get the info from this pack for some reason;
1727                 * fall back to oid_object_info, which may find another copy.
1728                 * And if that fails, the error will be recorded in oe_type(entry)
1729                 * and dealt with in prepare_pack().
1730                 */
1731                oe_set_type(entry,
1732                            oid_object_info(the_repository, &entry->idx.oid, &size));
1733        } else {
1734                oe_set_type(entry, type);
1735        }
1736        SET_SIZE(entry, size);
1737}
1738
1739/*
1740 * Follow the chain of deltas from this entry onward, throwing away any links
1741 * that cause us to hit a cycle (as determined by the DFS state flags in
1742 * the entries).
1743 *
1744 * We also detect too-long reused chains that would violate our --depth
1745 * limit.
1746 */
1747static void break_delta_chains(struct object_entry *entry)
1748{
1749        /*
1750         * The actual depth of each object we will write is stored as an int,
1751         * as it cannot exceed our int "depth" limit. But before we break
1752         * changes based no that limit, we may potentially go as deep as the
1753         * number of objects, which is elsewhere bounded to a uint32_t.
1754         */
1755        uint32_t total_depth;
1756        struct object_entry *cur, *next;
1757
1758        for (cur = entry, total_depth = 0;
1759             cur;
1760             cur = DELTA(cur), total_depth++) {
1761                if (cur->dfs_state == DFS_DONE) {
1762                        /*
1763                         * We've already seen this object and know it isn't
1764                         * part of a cycle. We do need to append its depth
1765                         * to our count.
1766                         */
1767                        total_depth += cur->depth;
1768                        break;
1769                }
1770
1771                /*
1772                 * We break cycles before looping, so an ACTIVE state (or any
1773                 * other cruft which made its way into the state variable)
1774                 * is a bug.
1775                 */
1776                if (cur->dfs_state != DFS_NONE)
1777                        BUG("confusing delta dfs state in first pass: %d",
1778                            cur->dfs_state);
1779
1780                /*
1781                 * Now we know this is the first time we've seen the object. If
1782                 * it's not a delta, we're done traversing, but we'll mark it
1783                 * done to save time on future traversals.
1784                 */
1785                if (!DELTA(cur)) {
1786                        cur->dfs_state = DFS_DONE;
1787                        break;
1788                }
1789
1790                /*
1791                 * Mark ourselves as active and see if the next step causes
1792                 * us to cycle to another active object. It's important to do
1793                 * this _before_ we loop, because it impacts where we make the
1794                 * cut, and thus how our total_depth counter works.
1795                 * E.g., We may see a partial loop like:
1796                 *
1797                 *   A -> B -> C -> D -> B
1798                 *
1799                 * Cutting B->C breaks the cycle. But now the depth of A is
1800                 * only 1, and our total_depth counter is at 3. The size of the
1801                 * error is always one less than the size of the cycle we
1802                 * broke. Commits C and D were "lost" from A's chain.
1803                 *
1804                 * If we instead cut D->B, then the depth of A is correct at 3.
1805                 * We keep all commits in the chain that we examined.
1806                 */
1807                cur->dfs_state = DFS_ACTIVE;
1808                if (DELTA(cur)->dfs_state == DFS_ACTIVE) {
1809                        drop_reused_delta(cur);
1810                        cur->dfs_state = DFS_DONE;
1811                        break;
1812                }
1813        }
1814
1815        /*
1816         * And now that we've gone all the way to the bottom of the chain, we
1817         * need to clear the active flags and set the depth fields as
1818         * appropriate. Unlike the loop above, which can quit when it drops a
1819         * delta, we need to keep going to look for more depth cuts. So we need
1820         * an extra "next" pointer to keep going after we reset cur->delta.
1821         */
1822        for (cur = entry; cur; cur = next) {
1823                next = DELTA(cur);
1824
1825                /*
1826                 * We should have a chain of zero or more ACTIVE states down to
1827                 * a final DONE. We can quit after the DONE, because either it
1828                 * has no bases, or we've already handled them in a previous
1829                 * call.
1830                 */
1831                if (cur->dfs_state == DFS_DONE)
1832                        break;
1833                else if (cur->dfs_state != DFS_ACTIVE)
1834                        BUG("confusing delta dfs state in second pass: %d",
1835                            cur->dfs_state);
1836
1837                /*
1838                 * If the total_depth is more than depth, then we need to snip
1839                 * the chain into two or more smaller chains that don't exceed
1840                 * the maximum depth. Most of the resulting chains will contain
1841                 * (depth + 1) entries (i.e., depth deltas plus one base), and
1842                 * the last chain (i.e., the one containing entry) will contain
1843                 * whatever entries are left over, namely
1844                 * (total_depth % (depth + 1)) of them.
1845                 *
1846                 * Since we are iterating towards decreasing depth, we need to
1847                 * decrement total_depth as we go, and we need to write to the
1848                 * entry what its final depth will be after all of the
1849                 * snipping. Since we're snipping into chains of length (depth
1850                 * + 1) entries, the final depth of an entry will be its
1851                 * original depth modulo (depth + 1). Any time we encounter an
1852                 * entry whose final depth is supposed to be zero, we snip it
1853                 * from its delta base, thereby making it so.
1854                 */
1855                cur->depth = (total_depth--) % (depth + 1);
1856                if (!cur->depth)
1857                        drop_reused_delta(cur);
1858
1859                cur->dfs_state = DFS_DONE;
1860        }
1861}
1862
1863static void get_object_details(void)
1864{
1865        uint32_t i;
1866        struct object_entry **sorted_by_offset;
1867
1868        if (progress)
1869                progress_state = start_progress(_("Counting objects"),
1870                                                to_pack.nr_objects);
1871
1872        sorted_by_offset = xcalloc(to_pack.nr_objects, sizeof(struct object_entry *));
1873        for (i = 0; i < to_pack.nr_objects; i++)
1874                sorted_by_offset[i] = to_pack.objects + i;
1875        QSORT(sorted_by_offset, to_pack.nr_objects, pack_offset_sort);
1876
1877        for (i = 0; i < to_pack.nr_objects; i++) {
1878                struct object_entry *entry = sorted_by_offset[i];
1879                check_object(entry);
1880                if (entry->type_valid &&
1881                    oe_size_greater_than(&to_pack, entry, big_file_threshold))
1882                        entry->no_try_delta = 1;
1883                display_progress(progress_state, i + 1);
1884        }
1885        stop_progress(&progress_state);
1886
1887        /*
1888         * This must happen in a second pass, since we rely on the delta
1889         * information for the whole list being completed.
1890         */
1891        for (i = 0; i < to_pack.nr_objects; i++)
1892                break_delta_chains(&to_pack.objects[i]);
1893
1894        free(sorted_by_offset);
1895}
1896
1897/*
1898 * We search for deltas in a list sorted by type, by filename hash, and then
1899 * by size, so that we see progressively smaller and smaller files.
1900 * That's because we prefer deltas to be from the bigger file
1901 * to the smaller -- deletes are potentially cheaper, but perhaps
1902 * more importantly, the bigger file is likely the more recent
1903 * one.  The deepest deltas are therefore the oldest objects which are
1904 * less susceptible to be accessed often.
1905 */
1906static int type_size_sort(const void *_a, const void *_b)
1907{
1908        const struct object_entry *a = *(struct object_entry **)_a;
1909        const struct object_entry *b = *(struct object_entry **)_b;
1910        const enum object_type a_type = oe_type(a);
1911        const enum object_type b_type = oe_type(b);
1912        const unsigned long a_size = SIZE(a);
1913        const unsigned long b_size = SIZE(b);
1914
1915        if (a_type > b_type)
1916                return -1;
1917        if (a_type < b_type)
1918                return 1;
1919        if (a->hash > b->hash)
1920                return -1;
1921        if (a->hash < b->hash)
1922                return 1;
1923        if (a->preferred_base > b->preferred_base)
1924                return -1;
1925        if (a->preferred_base < b->preferred_base)
1926                return 1;
1927        if (use_delta_islands) {
1928                const int island_cmp = island_delta_cmp(&a->idx.oid, &b->idx.oid);
1929                if (island_cmp)
1930                        return island_cmp;
1931        }
1932        if (a_size > b_size)
1933                return -1;
1934        if (a_size < b_size)
1935                return 1;
1936        return a < b ? -1 : (a > b);  /* newest first */
1937}
1938
1939struct unpacked {
1940        struct object_entry *entry;
1941        void *data;
1942        struct delta_index *index;
1943        unsigned depth;
1944};
1945
1946static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1947                           unsigned long delta_size)
1948{
1949        if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1950                return 0;
1951
1952        if (delta_size < cache_max_small_delta_size)
1953                return 1;
1954
1955        /* cache delta, if objects are large enough compared to delta size */
1956        if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1957                return 1;
1958
1959        return 0;
1960}
1961
1962/* Protect delta_cache_size */
1963static pthread_mutex_t cache_mutex;
1964#define cache_lock()            pthread_mutex_lock(&cache_mutex)
1965#define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1966
1967/*
1968 * Protect object list partitioning (e.g. struct thread_param) and
1969 * progress_state
1970 */
1971static pthread_mutex_t progress_mutex;
1972#define progress_lock()         pthread_mutex_lock(&progress_mutex)
1973#define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1974
1975/*
1976 * Access to struct object_entry is unprotected since each thread owns
1977 * a portion of the main object list. Just don't access object entries
1978 * ahead in the list because they can be stolen and would need
1979 * progress_mutex for protection.
1980 */
1981
1982/*
1983 * Return the size of the object without doing any delta
1984 * reconstruction (so non-deltas are true object sizes, but deltas
1985 * return the size of the delta data).
1986 */
1987unsigned long oe_get_size_slow(struct packing_data *pack,
1988                               const struct object_entry *e)
1989{
1990        struct packed_git *p;
1991        struct pack_window *w_curs;
1992        unsigned char *buf;
1993        enum object_type type;
1994        unsigned long used, avail, size;
1995
1996        if (e->type_ != OBJ_OFS_DELTA && e->type_ != OBJ_REF_DELTA) {
1997                packing_data_lock(&to_pack);
1998                if (oid_object_info(the_repository, &e->idx.oid, &size) < 0)
1999                        die(_("unable to get size of %s"),
2000                            oid_to_hex(&e->idx.oid));
2001                packing_data_unlock(&to_pack);
2002                return size;
2003        }
2004
2005        p = oe_in_pack(pack, e);
2006        if (!p)
2007                BUG("when e->type is a delta, it must belong to a pack");
2008
2009        packing_data_lock(&to_pack);
2010        w_curs = NULL;
2011        buf = use_pack(p, &w_curs, e->in_pack_offset, &avail);
2012        used = unpack_object_header_buffer(buf, avail, &type, &size);
2013        if (used == 0)
2014                die(_("unable to parse object header of %s"),
2015                    oid_to_hex(&e->idx.oid));
2016
2017        unuse_pack(&w_curs);
2018        packing_data_unlock(&to_pack);
2019        return size;
2020}
2021
2022static int try_delta(struct unpacked *trg, struct unpacked *src,
2023                     unsigned max_depth, unsigned long *mem_usage)
2024{
2025        struct object_entry *trg_entry = trg->entry;
2026        struct object_entry *src_entry = src->entry;
2027        unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
2028        unsigned ref_depth;
2029        enum object_type type;
2030        void *delta_buf;
2031
2032        /* Don't bother doing diffs between different types */
2033        if (oe_type(trg_entry) != oe_type(src_entry))
2034                return -1;
2035
2036        /*
2037         * We do not bother to try a delta that we discarded on an
2038         * earlier try, but only when reusing delta data.  Note that
2039         * src_entry that is marked as the preferred_base should always
2040         * be considered, as even if we produce a suboptimal delta against
2041         * it, we will still save the transfer cost, as we already know
2042         * the other side has it and we won't send src_entry at all.
2043         */
2044        if (reuse_delta && IN_PACK(trg_entry) &&
2045            IN_PACK(trg_entry) == IN_PACK(src_entry) &&
2046            !src_entry->preferred_base &&
2047            trg_entry->in_pack_type != OBJ_REF_DELTA &&
2048            trg_entry->in_pack_type != OBJ_OFS_DELTA)
2049                return 0;
2050
2051        /* Let's not bust the allowed depth. */
2052        if (src->depth >= max_depth)
2053                return 0;
2054
2055        /* Now some size filtering heuristics. */
2056        trg_size = SIZE(trg_entry);
2057        if (!DELTA(trg_entry)) {
2058                max_size = trg_size/2 - the_hash_algo->rawsz;
2059                ref_depth = 1;
2060        } else {
2061                max_size = DELTA_SIZE(trg_entry);
2062                ref_depth = trg->depth;
2063        }
2064        max_size = (uint64_t)max_size * (max_depth - src->depth) /
2065                                                (max_depth - ref_depth + 1);
2066        if (max_size == 0)
2067                return 0;
2068        src_size = SIZE(src_entry);
2069        sizediff = src_size < trg_size ? trg_size - src_size : 0;
2070        if (sizediff >= max_size)
2071                return 0;
2072        if (trg_size < src_size / 32)
2073                return 0;
2074
2075        if (!in_same_island(&trg->entry->idx.oid, &src->entry->idx.oid))
2076                return 0;
2077
2078        /* Load data if not already done */
2079        if (!trg->data) {
2080                packing_data_lock(&to_pack);
2081                trg->data = read_object_file(&trg_entry->idx.oid, &type, &sz);
2082                packing_data_unlock(&to_pack);
2083                if (!trg->data)
2084                        die(_("object %s cannot be read"),
2085                            oid_to_hex(&trg_entry->idx.oid));
2086                if (sz != trg_size)
2087                        die(_("object %s inconsistent object length (%"PRIuMAX" vs %"PRIuMAX")"),
2088                            oid_to_hex(&trg_entry->idx.oid), (uintmax_t)sz,
2089                            (uintmax_t)trg_size);
2090                *mem_usage += sz;
2091        }
2092        if (!src->data) {
2093                packing_data_lock(&to_pack);
2094                src->data = read_object_file(&src_entry->idx.oid, &type, &sz);
2095                packing_data_unlock(&to_pack);
2096                if (!src->data) {
2097                        if (src_entry->preferred_base) {
2098                                static int warned = 0;
2099                                if (!warned++)
2100                                        warning(_("object %s cannot be read"),
2101                                                oid_to_hex(&src_entry->idx.oid));
2102                                /*
2103                                 * Those objects are not included in the
2104                                 * resulting pack.  Be resilient and ignore
2105                                 * them if they can't be read, in case the
2106                                 * pack could be created nevertheless.
2107                                 */
2108                                return 0;
2109                        }
2110                        die(_("object %s cannot be read"),
2111                            oid_to_hex(&src_entry->idx.oid));
2112                }
2113                if (sz != src_size)
2114                        die(_("object %s inconsistent object length (%"PRIuMAX" vs %"PRIuMAX")"),
2115                            oid_to_hex(&src_entry->idx.oid), (uintmax_t)sz,
2116                            (uintmax_t)src_size);
2117                *mem_usage += sz;
2118        }
2119        if (!src->index) {
2120                src->index = create_delta_index(src->data, src_size);
2121                if (!src->index) {
2122                        static int warned = 0;
2123                        if (!warned++)
2124                                warning(_("suboptimal pack - out of memory"));
2125                        return 0;
2126                }
2127                *mem_usage += sizeof_delta_index(src->index);
2128        }
2129
2130        delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
2131        if (!delta_buf)
2132                return 0;
2133
2134        if (DELTA(trg_entry)) {
2135                /* Prefer only shallower same-sized deltas. */
2136                if (delta_size == DELTA_SIZE(trg_entry) &&
2137                    src->depth + 1 >= trg->depth) {
2138                        free(delta_buf);
2139                        return 0;
2140                }
2141        }
2142
2143        /*
2144         * Handle memory allocation outside of the cache
2145         * accounting lock.  Compiler will optimize the strangeness
2146         * away when NO_PTHREADS is defined.
2147         */
2148        free(trg_entry->delta_data);
2149        cache_lock();
2150        if (trg_entry->delta_data) {
2151                delta_cache_size -= DELTA_SIZE(trg_entry);
2152                trg_entry->delta_data = NULL;
2153        }
2154        if (delta_cacheable(src_size, trg_size, delta_size)) {
2155                delta_cache_size += delta_size;
2156                cache_unlock();
2157                trg_entry->delta_data = xrealloc(delta_buf, delta_size);
2158        } else {
2159                cache_unlock();
2160                free(delta_buf);
2161        }
2162
2163        SET_DELTA(trg_entry, src_entry);
2164        SET_DELTA_SIZE(trg_entry, delta_size);
2165        trg->depth = src->depth + 1;
2166
2167        return 1;
2168}
2169
2170static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
2171{
2172        struct object_entry *child = DELTA_CHILD(me);
2173        unsigned int m = n;
2174        while (child) {
2175                const unsigned int c = check_delta_limit(child, n + 1);
2176                if (m < c)
2177                        m = c;
2178                child = DELTA_SIBLING(child);
2179        }
2180        return m;
2181}
2182
2183static unsigned long free_unpacked(struct unpacked *n)
2184{
2185        unsigned long freed_mem = sizeof_delta_index(n->index);
2186        free_delta_index(n->index);
2187        n->index = NULL;
2188        if (n->data) {
2189                freed_mem += SIZE(n->entry);
2190                FREE_AND_NULL(n->data);
2191        }
2192        n->entry = NULL;
2193        n->depth = 0;
2194        return freed_mem;
2195}
2196
2197static void find_deltas(struct object_entry **list, unsigned *list_size,
2198                        int window, int depth, unsigned *processed)
2199{
2200        uint32_t i, idx = 0, count = 0;
2201        struct unpacked *array;
2202        unsigned long mem_usage = 0;
2203
2204        array = xcalloc(window, sizeof(struct unpacked));
2205
2206        for (;;) {
2207                struct object_entry *entry;
2208                struct unpacked *n = array + idx;
2209                int j, max_depth, best_base = -1;
2210
2211                progress_lock();
2212                if (!*list_size) {
2213                        progress_unlock();
2214                        break;
2215                }
2216                entry = *list++;
2217                (*list_size)--;
2218                if (!entry->preferred_base) {
2219                        (*processed)++;
2220                        display_progress(progress_state, *processed);
2221                }
2222                progress_unlock();
2223
2224                mem_usage -= free_unpacked(n);
2225                n->entry = entry;
2226
2227                while (window_memory_limit &&
2228                       mem_usage > window_memory_limit &&
2229                       count > 1) {
2230                        const uint32_t tail = (idx + window - count) % window;
2231                        mem_usage -= free_unpacked(array + tail);
2232                        count--;
2233                }
2234
2235                /* We do not compute delta to *create* objects we are not
2236                 * going to pack.
2237                 */
2238                if (entry->preferred_base)
2239                        goto next;
2240
2241                /*
2242                 * If the current object is at pack edge, take the depth the
2243                 * objects that depend on the current object into account
2244                 * otherwise they would become too deep.
2245                 */
2246                max_depth = depth;
2247                if (DELTA_CHILD(entry)) {
2248                        max_depth -= check_delta_limit(entry, 0);
2249                        if (max_depth <= 0)
2250                                goto next;
2251                }
2252
2253                j = window;
2254                while (--j > 0) {
2255                        int ret;
2256                        uint32_t other_idx = idx + j;
2257                        struct unpacked *m;
2258                        if (other_idx >= window)
2259                                other_idx -= window;
2260                        m = array + other_idx;
2261                        if (!m->entry)
2262                                break;
2263                        ret = try_delta(n, m, max_depth, &mem_usage);
2264                        if (ret < 0)
2265                                break;
2266                        else if (ret > 0)
2267                                best_base = other_idx;
2268                }
2269
2270                /*
2271                 * If we decided to cache the delta data, then it is best
2272                 * to compress it right away.  First because we have to do
2273                 * it anyway, and doing it here while we're threaded will
2274                 * save a lot of time in the non threaded write phase,
2275                 * as well as allow for caching more deltas within
2276                 * the same cache size limit.
2277                 * ...
2278                 * But only if not writing to stdout, since in that case
2279                 * the network is most likely throttling writes anyway,
2280                 * and therefore it is best to go to the write phase ASAP
2281                 * instead, as we can afford spending more time compressing
2282                 * between writes at that moment.
2283                 */
2284                if (entry->delta_data && !pack_to_stdout) {
2285                        unsigned long size;
2286
2287                        size = do_compress(&entry->delta_data, DELTA_SIZE(entry));
2288                        if (size < (1U << OE_Z_DELTA_BITS)) {
2289                                entry->z_delta_size = size;
2290                                cache_lock();
2291                                delta_cache_size -= DELTA_SIZE(entry);
2292                                delta_cache_size += entry->z_delta_size;
2293                                cache_unlock();
2294                        } else {
2295                                FREE_AND_NULL(entry->delta_data);
2296                                entry->z_delta_size = 0;
2297                        }
2298                }
2299
2300                /* if we made n a delta, and if n is already at max
2301                 * depth, leaving it in the window is pointless.  we
2302                 * should evict it first.
2303                 */
2304                if (DELTA(entry) && max_depth <= n->depth)
2305                        continue;
2306
2307                /*
2308                 * Move the best delta base up in the window, after the
2309                 * currently deltified object, to keep it longer.  It will
2310                 * be the first base object to be attempted next.
2311                 */
2312                if (DELTA(entry)) {
2313                        struct unpacked swap = array[best_base];
2314                        int dist = (window + idx - best_base) % window;
2315                        int dst = best_base;
2316                        while (dist--) {
2317                                int src = (dst + 1) % window;
2318                                array[dst] = array[src];
2319                                dst = src;
2320                        }
2321                        array[dst] = swap;
2322                }
2323
2324                next:
2325                idx++;
2326                if (count + 1 < window)
2327                        count++;
2328                if (idx >= window)
2329                        idx = 0;
2330        }
2331
2332        for (i = 0; i < window; ++i) {
2333                free_delta_index(array[i].index);
2334                free(array[i].data);
2335        }
2336        free(array);
2337}
2338
2339static void try_to_free_from_threads(size_t size)
2340{
2341        packing_data_lock(&to_pack);
2342        release_pack_memory(size);
2343        packing_data_unlock(&to_pack);
2344}
2345
2346static try_to_free_t old_try_to_free_routine;
2347
2348/*
2349 * The main object list is split into smaller lists, each is handed to
2350 * one worker.
2351 *
2352 * The main thread waits on the condition that (at least) one of the workers
2353 * has stopped working (which is indicated in the .working member of
2354 * struct thread_params).
2355 *
2356 * When a work thread has completed its work, it sets .working to 0 and
2357 * signals the main thread and waits on the condition that .data_ready
2358 * becomes 1.
2359 *
2360 * The main thread steals half of the work from the worker that has
2361 * most work left to hand it to the idle worker.
2362 */
2363
2364struct thread_params {
2365        pthread_t thread;
2366        struct object_entry **list;
2367        unsigned list_size;
2368        unsigned remaining;
2369        int window;
2370        int depth;
2371        int working;
2372        int data_ready;
2373        pthread_mutex_t mutex;
2374        pthread_cond_t cond;
2375        unsigned *processed;
2376};
2377
2378static pthread_cond_t progress_cond;
2379
2380/*
2381 * Mutex and conditional variable can't be statically-initialized on Windows.
2382 */
2383static void init_threaded_search(void)
2384{
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(&cache_mutex);
2396        pthread_mutex_destroy(&progress_mutex);
2397}
2398
2399static void *threaded_find_deltas(void *arg)
2400{
2401        struct thread_params *me = arg;
2402
2403        progress_lock();
2404        while (me->remaining) {
2405                progress_unlock();
2406
2407                find_deltas(me->list, &me->remaining,
2408                            me->window, me->depth, me->processed);
2409
2410                progress_lock();
2411                me->working = 0;
2412                pthread_cond_signal(&progress_cond);
2413                progress_unlock();
2414
2415                /*
2416                 * We must not set ->data_ready before we wait on the
2417                 * condition because the main thread may have set it to 1
2418                 * before we get here. In order to be sure that new
2419                 * work is available if we see 1 in ->data_ready, it
2420                 * was initialized to 0 before this thread was spawned
2421                 * and we reset it to 0 right away.
2422                 */
2423                pthread_mutex_lock(&me->mutex);
2424                while (!me->data_ready)
2425                        pthread_cond_wait(&me->cond, &me->mutex);
2426                me->data_ready = 0;
2427                pthread_mutex_unlock(&me->mutex);
2428
2429                progress_lock();
2430        }
2431        progress_unlock();
2432        /* leave ->working 1 so that this doesn't get more work assigned */
2433        return NULL;
2434}
2435
2436static void ll_find_deltas(struct object_entry **list, unsigned list_size,
2437                           int window, int depth, unsigned *processed)
2438{
2439        struct thread_params *p;
2440        int i, ret, active_threads = 0;
2441
2442        init_threaded_search();
2443
2444        if (delta_search_threads <= 1) {
2445                find_deltas(list, &list_size, window, depth, processed);
2446                cleanup_threaded_search();
2447                return;
2448        }
2449        if (progress > pack_to_stdout)
2450                fprintf_ln(stderr, _("Delta compression using up to %d threads"),
2451                           delta_search_threads);
2452        p = xcalloc(delta_search_threads, sizeof(*p));
2453
2454        /* Partition the work amongst work threads. */
2455        for (i = 0; i < delta_search_threads; i++) {
2456                unsigned sub_size = list_size / (delta_search_threads - i);
2457
2458                /* don't use too small segments or no deltas will be found */
2459                if (sub_size < 2*window && i+1 < delta_search_threads)
2460                        sub_size = 0;
2461
2462                p[i].window = window;
2463                p[i].depth = depth;
2464                p[i].processed = processed;
2465                p[i].working = 1;
2466                p[i].data_ready = 0;
2467
2468                /* try to split chunks on "path" boundaries */
2469                while (sub_size && sub_size < list_size &&
2470                       list[sub_size]->hash &&
2471                       list[sub_size]->hash == list[sub_size-1]->hash)
2472                        sub_size++;
2473
2474                p[i].list = list;
2475                p[i].list_size = sub_size;
2476                p[i].remaining = sub_size;
2477
2478                list += sub_size;
2479                list_size -= sub_size;
2480        }
2481
2482        /* Start work threads. */
2483        for (i = 0; i < delta_search_threads; i++) {
2484                if (!p[i].list_size)
2485                        continue;
2486                pthread_mutex_init(&p[i].mutex, NULL);
2487                pthread_cond_init(&p[i].cond, NULL);
2488                ret = pthread_create(&p[i].thread, NULL,
2489                                     threaded_find_deltas, &p[i]);
2490                if (ret)
2491                        die(_("unable to create thread: %s"), strerror(ret));
2492                active_threads++;
2493        }
2494
2495        /*
2496         * Now let's wait for work completion.  Each time a thread is done
2497         * with its work, we steal half of the remaining work from the
2498         * thread with the largest number of unprocessed objects and give
2499         * it to that newly idle thread.  This ensure good load balancing
2500         * until the remaining object list segments are simply too short
2501         * to be worth splitting anymore.
2502         */
2503        while (active_threads) {
2504                struct thread_params *target = NULL;
2505                struct thread_params *victim = NULL;
2506                unsigned sub_size = 0;
2507
2508                progress_lock();
2509                for (;;) {
2510                        for (i = 0; !target && i < delta_search_threads; i++)
2511                                if (!p[i].working)
2512                                        target = &p[i];
2513                        if (target)
2514                                break;
2515                        pthread_cond_wait(&progress_cond, &progress_mutex);
2516                }
2517
2518                for (i = 0; i < delta_search_threads; i++)
2519                        if (p[i].remaining > 2*window &&
2520                            (!victim || victim->remaining < p[i].remaining))
2521                                victim = &p[i];
2522                if (victim) {
2523                        sub_size = victim->remaining / 2;
2524                        list = victim->list + victim->list_size - sub_size;
2525                        while (sub_size && list[0]->hash &&
2526                               list[0]->hash == list[-1]->hash) {
2527                                list++;
2528                                sub_size--;
2529                        }
2530                        if (!sub_size) {
2531                                /*
2532                                 * It is possible for some "paths" to have
2533                                 * so many objects that no hash boundary
2534                                 * might be found.  Let's just steal the
2535                                 * exact half in that case.
2536                                 */
2537                                sub_size = victim->remaining / 2;
2538                                list -= sub_size;
2539                        }
2540                        target->list = list;
2541                        victim->list_size -= sub_size;
2542                        victim->remaining -= sub_size;
2543                }
2544                target->list_size = sub_size;
2545                target->remaining = sub_size;
2546                target->working = 1;
2547                progress_unlock();
2548
2549                pthread_mutex_lock(&target->mutex);
2550                target->data_ready = 1;
2551                pthread_cond_signal(&target->cond);
2552                pthread_mutex_unlock(&target->mutex);
2553
2554                if (!sub_size) {
2555                        pthread_join(target->thread, NULL);
2556                        pthread_cond_destroy(&target->cond);
2557                        pthread_mutex_destroy(&target->mutex);
2558                        active_threads--;
2559                }
2560        }
2561        cleanup_threaded_search();
2562        free(p);
2563}
2564
2565static void add_tag_chain(const struct object_id *oid)
2566{
2567        struct tag *tag;
2568
2569        /*
2570         * We catch duplicates already in add_object_entry(), but we'd
2571         * prefer to do this extra check to avoid having to parse the
2572         * tag at all if we already know that it's being packed (e.g., if
2573         * it was included via bitmaps, we would not have parsed it
2574         * previously).
2575         */
2576        if (packlist_find(&to_pack, oid, NULL))
2577                return;
2578
2579        tag = lookup_tag(the_repository, oid);
2580        while (1) {
2581                if (!tag || parse_tag(tag) || !tag->tagged)
2582                        die(_("unable to pack objects reachable from tag %s"),
2583                            oid_to_hex(oid));
2584
2585                add_object_entry(&tag->object.oid, OBJ_TAG, NULL, 0);
2586
2587                if (tag->tagged->type != OBJ_TAG)
2588                        return;
2589
2590                tag = (struct tag *)tag->tagged;
2591        }
2592}
2593
2594static int add_ref_tag(const char *path, const struct object_id *oid, int flag, void *cb_data)
2595{
2596        struct object_id peeled;
2597
2598        if (starts_with(path, "refs/tags/") && /* is a tag? */
2599            !peel_ref(path, &peeled)    && /* peelable? */
2600            packlist_find(&to_pack, &peeled, NULL))      /* object packed? */
2601                add_tag_chain(oid);
2602        return 0;
2603}
2604
2605static void prepare_pack(int window, int depth)
2606{
2607        struct object_entry **delta_list;
2608        uint32_t i, nr_deltas;
2609        unsigned n;
2610
2611        if (use_delta_islands)
2612                resolve_tree_islands(the_repository, progress, &to_pack);
2613
2614        get_object_details();
2615
2616        /*
2617         * If we're locally repacking then we need to be doubly careful
2618         * from now on in order to make sure no stealth corruption gets
2619         * propagated to the new pack.  Clients receiving streamed packs
2620         * should validate everything they get anyway so no need to incur
2621         * the additional cost here in that case.
2622         */
2623        if (!pack_to_stdout)
2624                do_check_packed_object_crc = 1;
2625
2626        if (!to_pack.nr_objects || !window || !depth)
2627                return;
2628
2629        ALLOC_ARRAY(delta_list, to_pack.nr_objects);
2630        nr_deltas = n = 0;
2631
2632        for (i = 0; i < to_pack.nr_objects; i++) {
2633                struct object_entry *entry = to_pack.objects + i;
2634
2635                if (DELTA(entry))
2636                        /* This happens if we decided to reuse existing
2637                         * delta from a pack.  "reuse_delta &&" is implied.
2638                         */
2639                        continue;
2640
2641                if (!entry->type_valid ||
2642                    oe_size_less_than(&to_pack, entry, 50))
2643                        continue;
2644
2645                if (entry->no_try_delta)
2646                        continue;
2647
2648                if (!entry->preferred_base) {
2649                        nr_deltas++;
2650                        if (oe_type(entry) < 0)
2651                                die(_("unable to get type of object %s"),
2652                                    oid_to_hex(&entry->idx.oid));
2653                } else {
2654                        if (oe_type(entry) < 0) {
2655                                /*
2656                                 * This object is not found, but we
2657                                 * don't have to include it anyway.
2658                                 */
2659                                continue;
2660                        }
2661                }
2662
2663                delta_list[n++] = entry;
2664        }
2665
2666        if (nr_deltas && n > 1) {
2667                unsigned nr_done = 0;
2668                if (progress)
2669                        progress_state = start_progress(_("Compressing objects"),
2670                                                        nr_deltas);
2671                QSORT(delta_list, n, type_size_sort);
2672                ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
2673                stop_progress(&progress_state);
2674                if (nr_done != nr_deltas)
2675                        die(_("inconsistency with delta count"));
2676        }
2677        free(delta_list);
2678}
2679
2680static int git_pack_config(const char *k, const char *v, void *cb)
2681{
2682        if (!strcmp(k, "pack.window")) {
2683                window = git_config_int(k, v);
2684                return 0;
2685        }
2686        if (!strcmp(k, "pack.windowmemory")) {
2687                window_memory_limit = git_config_ulong(k, v);
2688                return 0;
2689        }
2690        if (!strcmp(k, "pack.depth")) {
2691                depth = git_config_int(k, v);
2692                return 0;
2693        }
2694        if (!strcmp(k, "pack.deltacachesize")) {
2695                max_delta_cache_size = git_config_int(k, v);
2696                return 0;
2697        }
2698        if (!strcmp(k, "pack.deltacachelimit")) {
2699                cache_max_small_delta_size = git_config_int(k, v);
2700                return 0;
2701        }
2702        if (!strcmp(k, "pack.writebitmaphashcache")) {
2703                if (git_config_bool(k, v))
2704                        write_bitmap_options |= BITMAP_OPT_HASH_CACHE;
2705                else
2706                        write_bitmap_options &= ~BITMAP_OPT_HASH_CACHE;
2707        }
2708        if (!strcmp(k, "pack.usebitmaps")) {
2709                use_bitmap_index_default = git_config_bool(k, v);
2710                return 0;
2711        }
2712        if (!strcmp(k, "pack.usesparse")) {
2713                sparse = git_config_bool(k, v);
2714                return 0;
2715        }
2716        if (!strcmp(k, "pack.threads")) {
2717                delta_search_threads = git_config_int(k, v);
2718                if (delta_search_threads < 0)
2719                        die(_("invalid number of threads specified (%d)"),
2720                            delta_search_threads);
2721                if (!HAVE_THREADS && delta_search_threads != 1) {
2722                        warning(_("no threads support, ignoring %s"), k);
2723                        delta_search_threads = 0;
2724                }
2725                return 0;
2726        }
2727        if (!strcmp(k, "pack.indexversion")) {
2728                pack_idx_opts.version = git_config_int(k, v);
2729                if (pack_idx_opts.version > 2)
2730                        die(_("bad pack.indexversion=%"PRIu32),
2731                            pack_idx_opts.version);
2732                return 0;
2733        }
2734        return git_default_config(k, v, cb);
2735}
2736
2737static void read_object_list_from_stdin(void)
2738{
2739        char line[GIT_MAX_HEXSZ + 1 + PATH_MAX + 2];
2740        struct object_id oid;
2741        const char *p;
2742
2743        for (;;) {
2744                if (!fgets(line, sizeof(line), stdin)) {
2745                        if (feof(stdin))
2746                                break;
2747                        if (!ferror(stdin))
2748                                die("BUG: fgets returned NULL, not EOF, not error!");
2749                        if (errno != EINTR)
2750                                die_errno("fgets");
2751                        clearerr(stdin);
2752                        continue;
2753                }
2754                if (line[0] == '-') {
2755                        if (get_oid_hex(line+1, &oid))
2756                                die(_("expected edge object ID, got garbage:\n %s"),
2757                                    line);
2758                        add_preferred_base(&oid);
2759                        continue;
2760                }
2761                if (parse_oid_hex(line, &oid, &p))
2762                        die(_("expected object ID, got garbage:\n %s"), line);
2763
2764                add_preferred_base_object(p + 1);
2765                add_object_entry(&oid, OBJ_NONE, p + 1, 0);
2766        }
2767}
2768
2769/* Remember to update object flag allocation in object.h */
2770#define OBJECT_ADDED (1u<<20)
2771
2772static void show_commit(struct commit *commit, void *data)
2773{
2774        add_object_entry(&commit->object.oid, OBJ_COMMIT, NULL, 0);
2775        commit->object.flags |= OBJECT_ADDED;
2776
2777        if (write_bitmap_index)
2778                index_commit_for_bitmap(commit);
2779
2780        if (use_delta_islands)
2781                propagate_island_marks(commit);
2782}
2783
2784static void show_object(struct object *obj, const char *name, void *data)
2785{
2786        add_preferred_base_object(name);
2787        add_object_entry(&obj->oid, obj->type, name, 0);
2788        obj->flags |= OBJECT_ADDED;
2789
2790        if (use_delta_islands) {
2791                const char *p;
2792                unsigned depth;
2793                struct object_entry *ent;
2794
2795                /* the empty string is a root tree, which is depth 0 */
2796                depth = *name ? 1 : 0;
2797                for (p = strchr(name, '/'); p; p = strchr(p + 1, '/'))
2798                        depth++;
2799
2800                ent = packlist_find(&to_pack, &obj->oid, NULL);
2801                if (ent && depth > oe_tree_depth(&to_pack, ent))
2802                        oe_set_tree_depth(&to_pack, ent, depth);
2803        }
2804}
2805
2806static void show_object__ma_allow_any(struct object *obj, const char *name, void *data)
2807{
2808        assert(arg_missing_action == MA_ALLOW_ANY);
2809
2810        /*
2811         * Quietly ignore ALL missing objects.  This avoids problems with
2812         * staging them now and getting an odd error later.
2813         */
2814        if (!has_object_file(&obj->oid))
2815                return;
2816
2817        show_object(obj, name, data);
2818}
2819
2820static void show_object__ma_allow_promisor(struct object *obj, const char *name, void *data)
2821{
2822        assert(arg_missing_action == MA_ALLOW_PROMISOR);
2823
2824        /*
2825         * Quietly ignore EXPECTED missing objects.  This avoids problems with
2826         * staging them now and getting an odd error later.
2827         */
2828        if (!has_object_file(&obj->oid) && is_promisor_object(&obj->oid))
2829                return;
2830
2831        show_object(obj, name, data);
2832}
2833
2834static int option_parse_missing_action(const struct option *opt,
2835                                       const char *arg, int unset)
2836{
2837        assert(arg);
2838        assert(!unset);
2839
2840        if (!strcmp(arg, "error")) {
2841                arg_missing_action = MA_ERROR;
2842                fn_show_object = show_object;
2843                return 0;
2844        }
2845
2846        if (!strcmp(arg, "allow-any")) {
2847                arg_missing_action = MA_ALLOW_ANY;
2848                fetch_if_missing = 0;
2849                fn_show_object = show_object__ma_allow_any;
2850                return 0;
2851        }
2852
2853        if (!strcmp(arg, "allow-promisor")) {
2854                arg_missing_action = MA_ALLOW_PROMISOR;
2855                fetch_if_missing = 0;
2856                fn_show_object = show_object__ma_allow_promisor;
2857                return 0;
2858        }
2859
2860        die(_("invalid value for --missing"));
2861        return 0;
2862}
2863
2864static void show_edge(struct commit *commit)
2865{
2866        add_preferred_base(&commit->object.oid);
2867}
2868
2869struct in_pack_object {
2870        off_t offset;
2871        struct object *object;
2872};
2873
2874struct in_pack {
2875        unsigned int alloc;
2876        unsigned int nr;
2877        struct in_pack_object *array;
2878};
2879
2880static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
2881{
2882        in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->oid.hash, p);
2883        in_pack->array[in_pack->nr].object = object;
2884        in_pack->nr++;
2885}
2886
2887/*
2888 * Compare the objects in the offset order, in order to emulate the
2889 * "git rev-list --objects" output that produced the pack originally.
2890 */
2891static int ofscmp(const void *a_, const void *b_)
2892{
2893        struct in_pack_object *a = (struct in_pack_object *)a_;
2894        struct in_pack_object *b = (struct in_pack_object *)b_;
2895
2896        if (a->offset < b->offset)
2897                return -1;
2898        else if (a->offset > b->offset)
2899                return 1;
2900        else
2901                return oidcmp(&a->object->oid, &b->object->oid);
2902}
2903
2904static void add_objects_in_unpacked_packs(void)
2905{
2906        struct packed_git *p;
2907        struct in_pack in_pack;
2908        uint32_t i;
2909
2910        memset(&in_pack, 0, sizeof(in_pack));
2911
2912        for (p = get_all_packs(the_repository); p; p = p->next) {
2913                struct object_id oid;
2914                struct object *o;
2915
2916                if (!p->pack_local || p->pack_keep || p->pack_keep_in_core)
2917                        continue;
2918                if (open_pack_index(p))
2919                        die(_("cannot open pack index"));
2920
2921                ALLOC_GROW(in_pack.array,
2922                           in_pack.nr + p->num_objects,
2923                           in_pack.alloc);
2924
2925                for (i = 0; i < p->num_objects; i++) {
2926                        nth_packed_object_oid(&oid, p, i);
2927                        o = lookup_unknown_object(&oid);
2928                        if (!(o->flags & OBJECT_ADDED))
2929                                mark_in_pack_object(o, p, &in_pack);
2930                        o->flags |= OBJECT_ADDED;
2931                }
2932        }
2933
2934        if (in_pack.nr) {
2935                QSORT(in_pack.array, in_pack.nr, ofscmp);
2936                for (i = 0; i < in_pack.nr; i++) {
2937                        struct object *o = in_pack.array[i].object;
2938                        add_object_entry(&o->oid, o->type, "", 0);
2939                }
2940        }
2941        free(in_pack.array);
2942}
2943
2944static int add_loose_object(const struct object_id *oid, const char *path,
2945                            void *data)
2946{
2947        enum object_type type = oid_object_info(the_repository, oid, NULL);
2948
2949        if (type < 0) {
2950                warning(_("loose object at %s could not be examined"), path);
2951                return 0;
2952        }
2953
2954        add_object_entry(oid, type, "", 0);
2955        return 0;
2956}
2957
2958/*
2959 * We actually don't even have to worry about reachability here.
2960 * add_object_entry will weed out duplicates, so we just add every
2961 * loose object we find.
2962 */
2963static void add_unreachable_loose_objects(void)
2964{
2965        for_each_loose_file_in_objdir(get_object_directory(),
2966                                      add_loose_object,
2967                                      NULL, NULL, NULL);
2968}
2969
2970static int has_sha1_pack_kept_or_nonlocal(const struct object_id *oid)
2971{
2972        static struct packed_git *last_found = (void *)1;
2973        struct packed_git *p;
2974
2975        p = (last_found != (void *)1) ? last_found :
2976                                        get_all_packs(the_repository);
2977
2978        while (p) {
2979                if ((!p->pack_local || p->pack_keep ||
2980                                p->pack_keep_in_core) &&
2981                        find_pack_entry_one(oid->hash, p)) {
2982                        last_found = p;
2983                        return 1;
2984                }
2985                if (p == last_found)
2986                        p = get_all_packs(the_repository);
2987                else
2988                        p = p->next;
2989                if (p == last_found)
2990                        p = p->next;
2991        }
2992        return 0;
2993}
2994
2995/*
2996 * Store a list of sha1s that are should not be discarded
2997 * because they are either written too recently, or are
2998 * reachable from another object that was.
2999 *
3000 * This is filled by get_object_list.
3001 */
3002static struct oid_array recent_objects;
3003
3004static int loosened_object_can_be_discarded(const struct object_id *oid,
3005                                            timestamp_t mtime)
3006{
3007        if (!unpack_unreachable_expiration)
3008                return 0;
3009        if (mtime > unpack_unreachable_expiration)
3010                return 0;
3011        if (oid_array_lookup(&recent_objects, oid) >= 0)
3012                return 0;
3013        return 1;
3014}
3015
3016static void loosen_unused_packed_objects(void)
3017{
3018        struct packed_git *p;
3019        uint32_t i;
3020        struct object_id oid;
3021
3022        for (p = get_all_packs(the_repository); p; p = p->next) {
3023                if (!p->pack_local || p->pack_keep || p->pack_keep_in_core)
3024                        continue;
3025
3026                if (open_pack_index(p))
3027                        die(_("cannot open pack index"));
3028
3029                for (i = 0; i < p->num_objects; i++) {
3030                        nth_packed_object_oid(&oid, p, i);
3031                        if (!packlist_find(&to_pack, &oid, NULL) &&
3032                            !has_sha1_pack_kept_or_nonlocal(&oid) &&
3033                            !loosened_object_can_be_discarded(&oid, p->mtime))
3034                                if (force_object_loose(&oid, p->mtime))
3035                                        die(_("unable to force loose object"));
3036                }
3037        }
3038}
3039
3040/*
3041 * This tracks any options which pack-reuse code expects to be on, or which a
3042 * reader of the pack might not understand, and which would therefore prevent
3043 * blind reuse of what we have on disk.
3044 */
3045static int pack_options_allow_reuse(void)
3046{
3047        return pack_to_stdout &&
3048               allow_ofs_delta &&
3049               !ignore_packed_keep_on_disk &&
3050               !ignore_packed_keep_in_core &&
3051               (!local || !have_non_local_packs) &&
3052               !incremental;
3053}
3054
3055static int get_object_list_from_bitmap(struct rev_info *revs)
3056{
3057        if (!(bitmap_git = prepare_bitmap_walk(revs)))
3058                return -1;
3059
3060        if (pack_options_allow_reuse() &&
3061            !reuse_partial_packfile_from_bitmap(
3062                        bitmap_git,
3063                        &reuse_packfile,
3064                        &reuse_packfile_objects,
3065                        &reuse_packfile_offset)) {
3066                assert(reuse_packfile_objects);
3067                nr_result += reuse_packfile_objects;
3068                display_progress(progress_state, nr_result);
3069        }
3070
3071        traverse_bitmap_commit_list(bitmap_git, &add_object_entry_from_bitmap);
3072        return 0;
3073}
3074
3075static void record_recent_object(struct object *obj,
3076                                 const char *name,
3077                                 void *data)
3078{
3079        oid_array_append(&recent_objects, &obj->oid);
3080}
3081
3082static void record_recent_commit(struct commit *commit, void *data)
3083{
3084        oid_array_append(&recent_objects, &commit->object.oid);
3085}
3086
3087static void get_object_list(int ac, const char **av)
3088{
3089        struct rev_info revs;
3090        struct setup_revision_opt s_r_opt = {
3091                .allow_exclude_promisor_objects = 1,
3092        };
3093        char line[1000];
3094        int flags = 0;
3095        int save_warning;
3096
3097        repo_init_revisions(the_repository, &revs, NULL);
3098        save_commit_buffer = 0;
3099        setup_revisions(ac, av, &revs, &s_r_opt);
3100
3101        /* make sure shallows are read */
3102        is_repository_shallow(the_repository);
3103
3104        save_warning = warn_on_object_refname_ambiguity;
3105        warn_on_object_refname_ambiguity = 0;
3106
3107        while (fgets(line, sizeof(line), stdin) != NULL) {
3108                int len = strlen(line);
3109                if (len && line[len - 1] == '\n')
3110                        line[--len] = 0;
3111                if (!len)
3112                        break;
3113                if (*line == '-') {
3114                        if (!strcmp(line, "--not")) {
3115                                flags ^= UNINTERESTING;
3116                                write_bitmap_index = 0;
3117                                continue;
3118                        }
3119                        if (starts_with(line, "--shallow ")) {
3120                                struct object_id oid;
3121                                if (get_oid_hex(line + 10, &oid))
3122                                        die("not an SHA-1 '%s'", line + 10);
3123                                register_shallow(the_repository, &oid);
3124                                use_bitmap_index = 0;
3125                                continue;
3126                        }
3127                        die(_("not a rev '%s'"), line);
3128                }
3129                if (handle_revision_arg(line, &revs, flags, REVARG_CANNOT_BE_FILENAME))
3130                        die(_("bad revision '%s'"), line);
3131        }
3132
3133        warn_on_object_refname_ambiguity = save_warning;
3134
3135        if (use_bitmap_index && !get_object_list_from_bitmap(&revs))
3136                return;
3137
3138        if (use_delta_islands)
3139                load_delta_islands(the_repository, progress);
3140
3141        if (prepare_revision_walk(&revs))
3142                die(_("revision walk setup failed"));
3143        mark_edges_uninteresting(&revs, show_edge, sparse);
3144
3145        if (!fn_show_object)
3146                fn_show_object = show_object;
3147        traverse_commit_list_filtered(&filter_options, &revs,
3148                                      show_commit, fn_show_object, NULL,
3149                                      NULL);
3150
3151        if (unpack_unreachable_expiration) {
3152                revs.ignore_missing_links = 1;
3153                if (add_unseen_recent_objects_to_traversal(&revs,
3154                                unpack_unreachable_expiration))
3155                        die(_("unable to add recent objects"));
3156                if (prepare_revision_walk(&revs))
3157                        die(_("revision walk setup failed"));
3158                traverse_commit_list(&revs, record_recent_commit,
3159                                     record_recent_object, NULL);
3160        }
3161
3162        if (keep_unreachable)
3163                add_objects_in_unpacked_packs();
3164        if (pack_loose_unreachable)
3165                add_unreachable_loose_objects();
3166        if (unpack_unreachable)
3167                loosen_unused_packed_objects();
3168
3169        oid_array_clear(&recent_objects);
3170}
3171
3172static void add_extra_kept_packs(const struct string_list *names)
3173{
3174        struct packed_git *p;
3175
3176        if (!names->nr)
3177                return;
3178
3179        for (p = get_all_packs(the_repository); p; p = p->next) {
3180                const char *name = basename(p->pack_name);
3181                int i;
3182
3183                if (!p->pack_local)
3184                        continue;
3185
3186                for (i = 0; i < names->nr; i++)
3187                        if (!fspathcmp(name, names->items[i].string))
3188                                break;
3189
3190                if (i < names->nr) {
3191                        p->pack_keep_in_core = 1;
3192                        ignore_packed_keep_in_core = 1;
3193                        continue;
3194                }
3195        }
3196}
3197
3198static int option_parse_index_version(const struct option *opt,
3199                                      const char *arg, int unset)
3200{
3201        char *c;
3202        const char *val = arg;
3203
3204        BUG_ON_OPT_NEG(unset);
3205
3206        pack_idx_opts.version = strtoul(val, &c, 10);
3207        if (pack_idx_opts.version > 2)
3208                die(_("unsupported index version %s"), val);
3209        if (*c == ',' && c[1])
3210                pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
3211        if (*c || pack_idx_opts.off32_limit & 0x80000000)
3212                die(_("bad index version '%s'"), val);
3213        return 0;
3214}
3215
3216static int option_parse_unpack_unreachable(const struct option *opt,
3217                                           const char *arg, int unset)
3218{
3219        if (unset) {
3220                unpack_unreachable = 0;
3221                unpack_unreachable_expiration = 0;
3222        }
3223        else {
3224                unpack_unreachable = 1;
3225                if (arg)
3226                        unpack_unreachable_expiration = approxidate(arg);
3227        }
3228        return 0;
3229}
3230
3231int cmd_pack_objects(int argc, const char **argv, const char *prefix)
3232{
3233        int use_internal_rev_list = 0;
3234        int shallow = 0;
3235        int all_progress_implied = 0;
3236        struct argv_array rp = ARGV_ARRAY_INIT;
3237        int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
3238        int rev_list_index = 0;
3239        struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
3240        struct option pack_objects_options[] = {
3241                OPT_SET_INT('q', "quiet", &progress,
3242                            N_("do not show progress meter"), 0),
3243                OPT_SET_INT(0, "progress", &progress,
3244                            N_("show progress meter"), 1),
3245                OPT_SET_INT(0, "all-progress", &progress,
3246                            N_("show progress meter during object writing phase"), 2),
3247                OPT_BOOL(0, "all-progress-implied",
3248                         &all_progress_implied,
3249                         N_("similar to --all-progress when progress meter is shown")),
3250                { OPTION_CALLBACK, 0, "index-version", NULL, N_("<version>[,<offset>]"),
3251                  N_("write the pack index file in the specified idx format version"),
3252                  PARSE_OPT_NONEG, option_parse_index_version },
3253                OPT_MAGNITUDE(0, "max-pack-size", &pack_size_limit,
3254                              N_("maximum size of each output pack file")),
3255                OPT_BOOL(0, "local", &local,
3256                         N_("ignore borrowed objects from alternate object store")),
3257                OPT_BOOL(0, "incremental", &incremental,
3258                         N_("ignore packed objects")),
3259                OPT_INTEGER(0, "window", &window,
3260                            N_("limit pack window by objects")),
3261                OPT_MAGNITUDE(0, "window-memory", &window_memory_limit,
3262                              N_("limit pack window by memory in addition to object limit")),
3263                OPT_INTEGER(0, "depth", &depth,
3264                            N_("maximum length of delta chain allowed in the resulting pack")),
3265                OPT_BOOL(0, "reuse-delta", &reuse_delta,
3266                         N_("reuse existing deltas")),
3267                OPT_BOOL(0, "reuse-object", &reuse_object,
3268                         N_("reuse existing objects")),
3269                OPT_BOOL(0, "delta-base-offset", &allow_ofs_delta,
3270                         N_("use OFS_DELTA objects")),
3271                OPT_INTEGER(0, "threads", &delta_search_threads,
3272                            N_("use threads when searching for best delta matches")),
3273                OPT_BOOL(0, "non-empty", &non_empty,
3274                         N_("do not create an empty pack output")),
3275                OPT_BOOL(0, "revs", &use_internal_rev_list,
3276                         N_("read revision arguments from standard input")),
3277                OPT_SET_INT_F(0, "unpacked", &rev_list_unpacked,
3278                              N_("limit the objects to those that are not yet packed"),
3279                              1, PARSE_OPT_NONEG),
3280                OPT_SET_INT_F(0, "all", &rev_list_all,
3281                              N_("include objects reachable from any reference"),
3282                              1, PARSE_OPT_NONEG),
3283                OPT_SET_INT_F(0, "reflog", &rev_list_reflog,
3284                              N_("include objects referred by reflog entries"),
3285                              1, PARSE_OPT_NONEG),
3286                OPT_SET_INT_F(0, "indexed-objects", &rev_list_index,
3287                              N_("include objects referred to by the index"),
3288                              1, PARSE_OPT_NONEG),
3289                OPT_BOOL(0, "stdout", &pack_to_stdout,
3290                         N_("output pack to stdout")),
3291                OPT_BOOL(0, "include-tag", &include_tag,
3292                         N_("include tag objects that refer to objects to be packed")),
3293                OPT_BOOL(0, "keep-unreachable", &keep_unreachable,
3294                         N_("keep unreachable objects")),
3295                OPT_BOOL(0, "pack-loose-unreachable", &pack_loose_unreachable,
3296                         N_("pack loose unreachable objects")),
3297                { OPTION_CALLBACK, 0, "unpack-unreachable", NULL, N_("time"),
3298                  N_("unpack unreachable objects newer than <time>"),
3299                  PARSE_OPT_OPTARG, option_parse_unpack_unreachable },
3300                OPT_BOOL(0, "sparse", &sparse,
3301                         N_("use the sparse reachability algorithm")),
3302                OPT_BOOL(0, "thin", &thin,
3303                         N_("create thin packs")),
3304                OPT_BOOL(0, "shallow", &shallow,
3305                         N_("create packs suitable for shallow fetches")),
3306                OPT_BOOL(0, "honor-pack-keep", &ignore_packed_keep_on_disk,
3307                         N_("ignore packs that have companion .keep file")),
3308                OPT_STRING_LIST(0, "keep-pack", &keep_pack_list, N_("name"),
3309                                N_("ignore this pack")),
3310                OPT_INTEGER(0, "compression", &pack_compression_level,
3311                            N_("pack compression level")),
3312                OPT_SET_INT(0, "keep-true-parents", &grafts_replace_parents,
3313                            N_("do not hide commits by grafts"), 0),
3314                OPT_BOOL(0, "use-bitmap-index", &use_bitmap_index,
3315                         N_("use a bitmap index if available to speed up counting objects")),
3316                OPT_BOOL(0, "write-bitmap-index", &write_bitmap_index,
3317                         N_("write a bitmap index together with the pack index")),
3318                OPT_PARSE_LIST_OBJECTS_FILTER(&filter_options),
3319                { OPTION_CALLBACK, 0, "missing", NULL, N_("action"),
3320                  N_("handling for missing objects"), PARSE_OPT_NONEG,
3321                  option_parse_missing_action },
3322                OPT_BOOL(0, "exclude-promisor-objects", &exclude_promisor_objects,
3323                         N_("do not pack objects in promisor packfiles")),
3324                OPT_BOOL(0, "delta-islands", &use_delta_islands,
3325                         N_("respect islands during delta compression")),
3326                OPT_END(),
3327        };
3328
3329        if (DFS_NUM_STATES > (1 << OE_DFS_STATE_BITS))
3330                BUG("too many dfs states, increase OE_DFS_STATE_BITS");
3331
3332        read_replace_refs = 0;
3333
3334        sparse = git_env_bool("GIT_TEST_PACK_SPARSE", 0);
3335        reset_pack_idx_option(&pack_idx_opts);
3336        git_config(git_pack_config, NULL);
3337
3338        progress = isatty(2);
3339        argc = parse_options(argc, argv, prefix, pack_objects_options,
3340                             pack_usage, 0);
3341
3342        if (argc) {
3343                base_name = argv[0];
3344                argc--;
3345        }
3346        if (pack_to_stdout != !base_name || argc)
3347                usage_with_options(pack_usage, pack_objects_options);
3348
3349        if (depth >= (1 << OE_DEPTH_BITS)) {
3350                warning(_("delta chain depth %d is too deep, forcing %d"),
3351                        depth, (1 << OE_DEPTH_BITS) - 1);
3352                depth = (1 << OE_DEPTH_BITS) - 1;
3353        }
3354        if (cache_max_small_delta_size >= (1U << OE_Z_DELTA_BITS)) {
3355                warning(_("pack.deltaCacheLimit is too high, forcing %d"),
3356                        (1U << OE_Z_DELTA_BITS) - 1);
3357                cache_max_small_delta_size = (1U << OE_Z_DELTA_BITS) - 1;
3358        }
3359
3360        argv_array_push(&rp, "pack-objects");
3361        if (thin) {
3362                use_internal_rev_list = 1;
3363                argv_array_push(&rp, shallow
3364                                ? "--objects-edge-aggressive"
3365                                : "--objects-edge");
3366        } else
3367                argv_array_push(&rp, "--objects");
3368
3369        if (rev_list_all) {
3370                use_internal_rev_list = 1;
3371                argv_array_push(&rp, "--all");
3372        }
3373        if (rev_list_reflog) {
3374                use_internal_rev_list = 1;
3375                argv_array_push(&rp, "--reflog");
3376        }
3377        if (rev_list_index) {
3378                use_internal_rev_list = 1;
3379                argv_array_push(&rp, "--indexed-objects");
3380        }
3381        if (rev_list_unpacked) {
3382                use_internal_rev_list = 1;
3383                argv_array_push(&rp, "--unpacked");
3384        }
3385
3386        if (exclude_promisor_objects) {
3387                use_internal_rev_list = 1;
3388                fetch_if_missing = 0;
3389                argv_array_push(&rp, "--exclude-promisor-objects");
3390        }
3391        if (unpack_unreachable || keep_unreachable || pack_loose_unreachable)
3392                use_internal_rev_list = 1;
3393
3394        if (!reuse_object)
3395                reuse_delta = 0;
3396        if (pack_compression_level == -1)
3397                pack_compression_level = Z_DEFAULT_COMPRESSION;
3398        else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
3399                die(_("bad pack compression level %d"), pack_compression_level);
3400
3401        if (!delta_search_threads)      /* --threads=0 means autodetect */
3402                delta_search_threads = online_cpus();
3403
3404        if (!HAVE_THREADS && delta_search_threads != 1)
3405                warning(_("no threads support, ignoring --threads"));
3406        if (!pack_to_stdout && !pack_size_limit)
3407                pack_size_limit = pack_size_limit_cfg;
3408        if (pack_to_stdout && pack_size_limit)
3409                die(_("--max-pack-size cannot be used to build a pack for transfer"));
3410        if (pack_size_limit && pack_size_limit < 1024*1024) {
3411                warning(_("minimum pack size limit is 1 MiB"));
3412                pack_size_limit = 1024*1024;
3413        }
3414
3415        if (!pack_to_stdout && thin)
3416                die(_("--thin cannot be used to build an indexable pack"));
3417
3418        if (keep_unreachable && unpack_unreachable)
3419                die(_("--keep-unreachable and --unpack-unreachable are incompatible"));
3420        if (!rev_list_all || !rev_list_reflog || !rev_list_index)
3421                unpack_unreachable_expiration = 0;
3422
3423        if (filter_options.choice) {
3424                if (!pack_to_stdout)
3425                        die(_("cannot use --filter without --stdout"));
3426                use_bitmap_index = 0;
3427        }
3428
3429        /*
3430         * "soft" reasons not to use bitmaps - for on-disk repack by default we want
3431         *
3432         * - to produce good pack (with bitmap index not-yet-packed objects are
3433         *   packed in suboptimal order).
3434         *
3435         * - to use more robust pack-generation codepath (avoiding possible
3436         *   bugs in bitmap code and possible bitmap index corruption).
3437         */
3438        if (!pack_to_stdout)
3439                use_bitmap_index_default = 0;
3440
3441        if (use_bitmap_index < 0)
3442                use_bitmap_index = use_bitmap_index_default;
3443
3444        /* "hard" reasons not to use bitmaps; these just won't work at all */
3445        if (!use_internal_rev_list || (!pack_to_stdout && write_bitmap_index) || is_repository_shallow(the_repository))
3446                use_bitmap_index = 0;
3447
3448        if (pack_to_stdout || !rev_list_all)
3449                write_bitmap_index = 0;
3450
3451        if (use_delta_islands)
3452                argv_array_push(&rp, "--topo-order");
3453
3454        if (progress && all_progress_implied)
3455                progress = 2;
3456
3457        add_extra_kept_packs(&keep_pack_list);
3458        if (ignore_packed_keep_on_disk) {
3459                struct packed_git *p;
3460                for (p = get_all_packs(the_repository); p; p = p->next)
3461                        if (p->pack_local && p->pack_keep)
3462                                break;
3463                if (!p) /* no keep-able packs found */
3464                        ignore_packed_keep_on_disk = 0;
3465        }
3466        if (local) {
3467                /*
3468                 * unlike ignore_packed_keep_on_disk above, we do not
3469                 * want to unset "local" based on looking at packs, as
3470                 * it also covers non-local objects
3471                 */
3472                struct packed_git *p;
3473                for (p = get_all_packs(the_repository); p; p = p->next) {
3474                        if (!p->pack_local) {
3475                                have_non_local_packs = 1;
3476                                break;
3477                        }
3478                }
3479        }
3480
3481        trace2_region_enter("pack-objects", "enumerate-objects",
3482                            the_repository);
3483        prepare_packing_data(the_repository, &to_pack);
3484
3485        if (progress)
3486                progress_state = start_progress(_("Enumerating objects"), 0);
3487        if (!use_internal_rev_list)
3488                read_object_list_from_stdin();
3489        else {
3490                get_object_list(rp.argc, rp.argv);
3491                argv_array_clear(&rp);
3492        }
3493        cleanup_preferred_base();
3494        if (include_tag && nr_result)
3495                for_each_ref(add_ref_tag, NULL);
3496        stop_progress(&progress_state);
3497        trace2_region_leave("pack-objects", "enumerate-objects",
3498                            the_repository);
3499
3500        if (non_empty && !nr_result)
3501                return 0;
3502        if (nr_result) {
3503                trace2_region_enter("pack-objects", "prepare-pack",
3504                                    the_repository);
3505                prepare_pack(window, depth);
3506                trace2_region_leave("pack-objects", "prepare-pack",
3507                                    the_repository);
3508        }
3509
3510        trace2_region_enter("pack-objects", "write-pack-file", the_repository);
3511        write_pack_file();
3512        trace2_region_leave("pack-objects", "write-pack-file", the_repository);
3513
3514        if (progress)
3515                fprintf_ln(stderr,
3516                           _("Total %"PRIu32" (delta %"PRIu32"),"
3517                             " reused %"PRIu32" (delta %"PRIu32")"),
3518                           written, written_delta, reused, reused_delta);
3519        return 0;
3520}