builtin / pack-objects.con commit Merge branch 'gs/retire-mru' (8676223)
   1#include "builtin.h"
   2#include "cache.h"
   3#include "config.h"
   4#include "attr.h"
   5#include "object.h"
   6#include "blob.h"
   7#include "commit.h"
   8#include "tag.h"
   9#include "tree.h"
  10#include "delta.h"
  11#include "pack.h"
  12#include "pack-revindex.h"
  13#include "csum-file.h"
  14#include "tree-walk.h"
  15#include "diff.h"
  16#include "revision.h"
  17#include "list-objects.h"
  18#include "list-objects-filter.h"
  19#include "list-objects-filter-options.h"
  20#include "pack-objects.h"
  21#include "progress.h"
  22#include "refs.h"
  23#include "streaming.h"
  24#include "thread-utils.h"
  25#include "pack-bitmap.h"
  26#include "reachable.h"
  27#include "sha1-array.h"
  28#include "argv-array.h"
  29#include "list.h"
  30#include "packfile.h"
  31
  32static const char *pack_usage[] = {
  33        N_("git pack-objects --stdout [<options>...] [< <ref-list> | < <object-list>]"),
  34        N_("git pack-objects [<options>...] <base-name> [< <ref-list> | < <object-list>]"),
  35        NULL
  36};
  37
  38/*
  39 * Objects we are going to pack are collected in the `to_pack` structure.
  40 * It contains an array (dynamically expanded) of the object data, and a map
  41 * that can resolve SHA1s to their position in the array.
  42 */
  43static struct packing_data to_pack;
  44
  45static struct pack_idx_entry **written_list;
  46static uint32_t nr_result, nr_written;
  47
  48static int non_empty;
  49static int reuse_delta = 1, reuse_object = 1;
  50static int keep_unreachable, unpack_unreachable, include_tag;
  51static timestamp_t unpack_unreachable_expiration;
  52static int pack_loose_unreachable;
  53static int local;
  54static int have_non_local_packs;
  55static int incremental;
  56static int ignore_packed_keep;
  57static int allow_ofs_delta;
  58static struct pack_idx_option pack_idx_opts;
  59static const char *base_name;
  60static int progress = 1;
  61static int window = 10;
  62static unsigned long pack_size_limit;
  63static int depth = 50;
  64static int delta_search_threads;
  65static int pack_to_stdout;
  66static int num_preferred_base;
  67static struct progress *progress_state;
  68
  69static struct packed_git *reuse_packfile;
  70static uint32_t reuse_packfile_objects;
  71static off_t reuse_packfile_offset;
  72
  73static int use_bitmap_index_default = 1;
  74static int use_bitmap_index = -1;
  75static int write_bitmap_index;
  76static uint16_t write_bitmap_options;
  77
  78static int exclude_promisor_objects;
  79
  80static unsigned long delta_cache_size = 0;
  81static unsigned long max_delta_cache_size = 256 * 1024 * 1024;
  82static unsigned long cache_max_small_delta_size = 1000;
  83
  84static unsigned long window_memory_limit = 0;
  85
  86static struct list_objects_filter_options filter_options;
  87
  88enum missing_action {
  89        MA_ERROR = 0,      /* fail if any missing objects are encountered */
  90        MA_ALLOW_ANY,      /* silently allow ALL missing objects */
  91        MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
  92};
  93static enum missing_action arg_missing_action;
  94static show_object_fn fn_show_object;
  95
  96/*
  97 * stats
  98 */
  99static uint32_t written, written_delta;
 100static uint32_t reused, reused_delta;
 101
 102/*
 103 * Indexed commits
 104 */
 105static struct commit **indexed_commits;
 106static unsigned int indexed_commits_nr;
 107static unsigned int indexed_commits_alloc;
 108
 109static void index_commit_for_bitmap(struct commit *commit)
 110{
 111        if (indexed_commits_nr >= indexed_commits_alloc) {
 112                indexed_commits_alloc = (indexed_commits_alloc + 32) * 2;
 113                REALLOC_ARRAY(indexed_commits, indexed_commits_alloc);
 114        }
 115
 116        indexed_commits[indexed_commits_nr++] = commit;
 117}
 118
 119static void *get_delta(struct object_entry *entry)
 120{
 121        unsigned long size, base_size, delta_size;
 122        void *buf, *base_buf, *delta_buf;
 123        enum object_type type;
 124
 125        buf = read_sha1_file(entry->idx.oid.hash, &type, &size);
 126        if (!buf)
 127                die("unable to read %s", oid_to_hex(&entry->idx.oid));
 128        base_buf = read_sha1_file(entry->delta->idx.oid.hash, &type,
 129                                  &base_size);
 130        if (!base_buf)
 131                die("unable to read %s",
 132                    oid_to_hex(&entry->delta->idx.oid));
 133        delta_buf = diff_delta(base_buf, base_size,
 134                               buf, size, &delta_size, 0);
 135        if (!delta_buf || delta_size != entry->delta_size)
 136                die("delta size changed");
 137        free(buf);
 138        free(base_buf);
 139        return delta_buf;
 140}
 141
 142static unsigned long do_compress(void **pptr, unsigned long size)
 143{
 144        git_zstream stream;
 145        void *in, *out;
 146        unsigned long maxsize;
 147
 148        git_deflate_init(&stream, pack_compression_level);
 149        maxsize = git_deflate_bound(&stream, size);
 150
 151        in = *pptr;
 152        out = xmalloc(maxsize);
 153        *pptr = out;
 154
 155        stream.next_in = in;
 156        stream.avail_in = size;
 157        stream.next_out = out;
 158        stream.avail_out = maxsize;
 159        while (git_deflate(&stream, Z_FINISH) == Z_OK)
 160                ; /* nothing */
 161        git_deflate_end(&stream);
 162
 163        free(in);
 164        return stream.total_out;
 165}
 166
 167static unsigned long write_large_blob_data(struct git_istream *st, struct sha1file *f,
 168                                           const struct object_id *oid)
 169{
 170        git_zstream stream;
 171        unsigned char ibuf[1024 * 16];
 172        unsigned char obuf[1024 * 16];
 173        unsigned long olen = 0;
 174
 175        git_deflate_init(&stream, pack_compression_level);
 176
 177        for (;;) {
 178                ssize_t readlen;
 179                int zret = Z_OK;
 180                readlen = read_istream(st, ibuf, sizeof(ibuf));
 181                if (readlen == -1)
 182                        die(_("unable to read %s"), oid_to_hex(oid));
 183
 184                stream.next_in = ibuf;
 185                stream.avail_in = readlen;
 186                while ((stream.avail_in || readlen == 0) &&
 187                       (zret == Z_OK || zret == Z_BUF_ERROR)) {
 188                        stream.next_out = obuf;
 189                        stream.avail_out = sizeof(obuf);
 190                        zret = git_deflate(&stream, readlen ? 0 : Z_FINISH);
 191                        sha1write(f, obuf, stream.next_out - obuf);
 192                        olen += stream.next_out - obuf;
 193                }
 194                if (stream.avail_in)
 195                        die(_("deflate error (%d)"), zret);
 196                if (readlen == 0) {
 197                        if (zret != Z_STREAM_END)
 198                                die(_("deflate error (%d)"), zret);
 199                        break;
 200                }
 201        }
 202        git_deflate_end(&stream);
 203        return olen;
 204}
 205
 206/*
 207 * we are going to reuse the existing object data as is.  make
 208 * sure it is not corrupt.
 209 */
 210static int check_pack_inflate(struct packed_git *p,
 211                struct pack_window **w_curs,
 212                off_t offset,
 213                off_t len,
 214                unsigned long expect)
 215{
 216        git_zstream stream;
 217        unsigned char fakebuf[4096], *in;
 218        int st;
 219
 220        memset(&stream, 0, sizeof(stream));
 221        git_inflate_init(&stream);
 222        do {
 223                in = use_pack(p, w_curs, offset, &stream.avail_in);
 224                stream.next_in = in;
 225                stream.next_out = fakebuf;
 226                stream.avail_out = sizeof(fakebuf);
 227                st = git_inflate(&stream, Z_FINISH);
 228                offset += stream.next_in - in;
 229        } while (st == Z_OK || st == Z_BUF_ERROR);
 230        git_inflate_end(&stream);
 231        return (st == Z_STREAM_END &&
 232                stream.total_out == expect &&
 233                stream.total_in == len) ? 0 : -1;
 234}
 235
 236static void copy_pack_data(struct sha1file *f,
 237                struct packed_git *p,
 238                struct pack_window **w_curs,
 239                off_t offset,
 240                off_t len)
 241{
 242        unsigned char *in;
 243        unsigned long avail;
 244
 245        while (len) {
 246                in = use_pack(p, w_curs, offset, &avail);
 247                if (avail > len)
 248                        avail = (unsigned long)len;
 249                sha1write(f, in, avail);
 250                offset += avail;
 251                len -= avail;
 252        }
 253}
 254
 255/* Return 0 if we will bust the pack-size limit */
 256static unsigned long write_no_reuse_object(struct sha1file *f, struct object_entry *entry,
 257                                           unsigned long limit, int usable_delta)
 258{
 259        unsigned long size, datalen;
 260        unsigned char header[MAX_PACK_OBJECT_HEADER],
 261                      dheader[MAX_PACK_OBJECT_HEADER];
 262        unsigned hdrlen;
 263        enum object_type type;
 264        void *buf;
 265        struct git_istream *st = NULL;
 266
 267        if (!usable_delta) {
 268                if (entry->type == OBJ_BLOB &&
 269                    entry->size > big_file_threshold &&
 270                    (st = open_istream(entry->idx.oid.hash, &type, &size, NULL)) != NULL)
 271                        buf = NULL;
 272                else {
 273                        buf = read_sha1_file(entry->idx.oid.hash, &type,
 274                                             &size);
 275                        if (!buf)
 276                                die(_("unable to read %s"),
 277                                    oid_to_hex(&entry->idx.oid));
 278                }
 279                /*
 280                 * make sure no cached delta data remains from a
 281                 * previous attempt before a pack split occurred.
 282                 */
 283                FREE_AND_NULL(entry->delta_data);
 284                entry->z_delta_size = 0;
 285        } else if (entry->delta_data) {
 286                size = entry->delta_size;
 287                buf = entry->delta_data;
 288                entry->delta_data = NULL;
 289                type = (allow_ofs_delta && entry->delta->idx.offset) ?
 290                        OBJ_OFS_DELTA : OBJ_REF_DELTA;
 291        } else {
 292                buf = get_delta(entry);
 293                size = entry->delta_size;
 294                type = (allow_ofs_delta && entry->delta->idx.offset) ?
 295                        OBJ_OFS_DELTA : OBJ_REF_DELTA;
 296        }
 297
 298        if (st) /* large blob case, just assume we don't compress well */
 299                datalen = size;
 300        else if (entry->z_delta_size)
 301                datalen = entry->z_delta_size;
 302        else
 303                datalen = do_compress(&buf, size);
 304
 305        /*
 306         * The object header is a byte of 'type' followed by zero or
 307         * more bytes of length.
 308         */
 309        hdrlen = encode_in_pack_object_header(header, sizeof(header),
 310                                              type, size);
 311
 312        if (type == OBJ_OFS_DELTA) {
 313                /*
 314                 * Deltas with relative base contain an additional
 315                 * encoding of the relative offset for the delta
 316                 * base from this object's position in the pack.
 317                 */
 318                off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 319                unsigned pos = sizeof(dheader) - 1;
 320                dheader[pos] = ofs & 127;
 321                while (ofs >>= 7)
 322                        dheader[--pos] = 128 | (--ofs & 127);
 323                if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 324                        if (st)
 325                                close_istream(st);
 326                        free(buf);
 327                        return 0;
 328                }
 329                sha1write(f, header, hdrlen);
 330                sha1write(f, dheader + pos, sizeof(dheader) - pos);
 331                hdrlen += sizeof(dheader) - pos;
 332        } else if (type == OBJ_REF_DELTA) {
 333                /*
 334                 * Deltas with a base reference contain
 335                 * an additional 20 bytes for the base sha1.
 336                 */
 337                if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 338                        if (st)
 339                                close_istream(st);
 340                        free(buf);
 341                        return 0;
 342                }
 343                sha1write(f, header, hdrlen);
 344                sha1write(f, entry->delta->idx.oid.hash, 20);
 345                hdrlen += 20;
 346        } else {
 347                if (limit && hdrlen + datalen + 20 >= limit) {
 348                        if (st)
 349                                close_istream(st);
 350                        free(buf);
 351                        return 0;
 352                }
 353                sha1write(f, header, hdrlen);
 354        }
 355        if (st) {
 356                datalen = write_large_blob_data(st, f, &entry->idx.oid);
 357                close_istream(st);
 358        } else {
 359                sha1write(f, buf, datalen);
 360                free(buf);
 361        }
 362
 363        return hdrlen + datalen;
 364}
 365
 366/* Return 0 if we will bust the pack-size limit */
 367static off_t write_reuse_object(struct sha1file *f, struct object_entry *entry,
 368                                unsigned long limit, int usable_delta)
 369{
 370        struct packed_git *p = entry->in_pack;
 371        struct pack_window *w_curs = NULL;
 372        struct revindex_entry *revidx;
 373        off_t offset;
 374        enum object_type type = entry->type;
 375        off_t datalen;
 376        unsigned char header[MAX_PACK_OBJECT_HEADER],
 377                      dheader[MAX_PACK_OBJECT_HEADER];
 378        unsigned hdrlen;
 379
 380        if (entry->delta)
 381                type = (allow_ofs_delta && entry->delta->idx.offset) ?
 382                        OBJ_OFS_DELTA : OBJ_REF_DELTA;
 383        hdrlen = encode_in_pack_object_header(header, sizeof(header),
 384                                              type, entry->size);
 385
 386        offset = entry->in_pack_offset;
 387        revidx = find_pack_revindex(p, offset);
 388        datalen = revidx[1].offset - offset;
 389        if (!pack_to_stdout && p->index_version > 1 &&
 390            check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 391                error("bad packed object CRC for %s",
 392                      oid_to_hex(&entry->idx.oid));
 393                unuse_pack(&w_curs);
 394                return write_no_reuse_object(f, entry, limit, usable_delta);
 395        }
 396
 397        offset += entry->in_pack_header_size;
 398        datalen -= entry->in_pack_header_size;
 399
 400        if (!pack_to_stdout && p->index_version == 1 &&
 401            check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
 402                error("corrupt packed object for %s",
 403                      oid_to_hex(&entry->idx.oid));
 404                unuse_pack(&w_curs);
 405                return write_no_reuse_object(f, entry, limit, usable_delta);
 406        }
 407
 408        if (type == OBJ_OFS_DELTA) {
 409                off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 410                unsigned pos = sizeof(dheader) - 1;
 411                dheader[pos] = ofs & 127;
 412                while (ofs >>= 7)
 413                        dheader[--pos] = 128 | (--ofs & 127);
 414                if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 415                        unuse_pack(&w_curs);
 416                        return 0;
 417                }
 418                sha1write(f, header, hdrlen);
 419                sha1write(f, dheader + pos, sizeof(dheader) - pos);
 420                hdrlen += sizeof(dheader) - pos;
 421                reused_delta++;
 422        } else if (type == OBJ_REF_DELTA) {
 423                if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 424                        unuse_pack(&w_curs);
 425                        return 0;
 426                }
 427                sha1write(f, header, hdrlen);
 428                sha1write(f, entry->delta->idx.oid.hash, 20);
 429                hdrlen += 20;
 430                reused_delta++;
 431        } else {
 432                if (limit && hdrlen + datalen + 20 >= limit) {
 433                        unuse_pack(&w_curs);
 434                        return 0;
 435                }
 436                sha1write(f, header, hdrlen);
 437        }
 438        copy_pack_data(f, p, &w_curs, offset, datalen);
 439        unuse_pack(&w_curs);
 440        reused++;
 441        return hdrlen + datalen;
 442}
 443
 444/* Return 0 if we will bust the pack-size limit */
 445static off_t write_object(struct sha1file *f,
 446                          struct object_entry *entry,
 447                          off_t write_offset)
 448{
 449        unsigned long limit;
 450        off_t len;
 451        int usable_delta, to_reuse;
 452
 453        if (!pack_to_stdout)
 454                crc32_begin(f);
 455
 456        /* apply size limit if limited packsize and not first object */
 457        if (!pack_size_limit || !nr_written)
 458                limit = 0;
 459        else if (pack_size_limit <= write_offset)
 460                /*
 461                 * the earlier object did not fit the limit; avoid
 462                 * mistaking this with unlimited (i.e. limit = 0).
 463                 */
 464                limit = 1;
 465        else
 466                limit = pack_size_limit - write_offset;
 467
 468        if (!entry->delta)
 469                usable_delta = 0;       /* no delta */
 470        else if (!pack_size_limit)
 471               usable_delta = 1;        /* unlimited packfile */
 472        else if (entry->delta->idx.offset == (off_t)-1)
 473                usable_delta = 0;       /* base was written to another pack */
 474        else if (entry->delta->idx.offset)
 475                usable_delta = 1;       /* base already exists in this pack */
 476        else
 477                usable_delta = 0;       /* base could end up in another pack */
 478
 479        if (!reuse_object)
 480                to_reuse = 0;   /* explicit */
 481        else if (!entry->in_pack)
 482                to_reuse = 0;   /* can't reuse what we don't have */
 483        else if (entry->type == OBJ_REF_DELTA || entry->type == OBJ_OFS_DELTA)
 484                                /* check_object() decided it for us ... */
 485                to_reuse = usable_delta;
 486                                /* ... but pack split may override that */
 487        else if (entry->type != entry->in_pack_type)
 488                to_reuse = 0;   /* pack has delta which is unusable */
 489        else if (entry->delta)
 490                to_reuse = 0;   /* we want to pack afresh */
 491        else
 492                to_reuse = 1;   /* we have it in-pack undeltified,
 493                                 * and we do not need to deltify it.
 494                                 */
 495
 496        if (!to_reuse)
 497                len = write_no_reuse_object(f, entry, limit, usable_delta);
 498        else
 499                len = write_reuse_object(f, entry, limit, usable_delta);
 500        if (!len)
 501                return 0;
 502
 503        if (usable_delta)
 504                written_delta++;
 505        written++;
 506        if (!pack_to_stdout)
 507                entry->idx.crc32 = crc32_end(f);
 508        return len;
 509}
 510
 511enum write_one_status {
 512        WRITE_ONE_SKIP = -1, /* already written */
 513        WRITE_ONE_BREAK = 0, /* writing this will bust the limit; not written */
 514        WRITE_ONE_WRITTEN = 1, /* normal */
 515        WRITE_ONE_RECURSIVE = 2 /* already scheduled to be written */
 516};
 517
 518static enum write_one_status write_one(struct sha1file *f,
 519                                       struct object_entry *e,
 520                                       off_t *offset)
 521{
 522        off_t size;
 523        int recursing;
 524
 525        /*
 526         * we set offset to 1 (which is an impossible value) to mark
 527         * the fact that this object is involved in "write its base
 528         * first before writing a deltified object" recursion.
 529         */
 530        recursing = (e->idx.offset == 1);
 531        if (recursing) {
 532                warning("recursive delta detected for object %s",
 533                        oid_to_hex(&e->idx.oid));
 534                return WRITE_ONE_RECURSIVE;
 535        } else if (e->idx.offset || e->preferred_base) {
 536                /* offset is non zero if object is written already. */
 537                return WRITE_ONE_SKIP;
 538        }
 539
 540        /* if we are deltified, write out base object first. */
 541        if (e->delta) {
 542                e->idx.offset = 1; /* now recurse */
 543                switch (write_one(f, e->delta, offset)) {
 544                case WRITE_ONE_RECURSIVE:
 545                        /* we cannot depend on this one */
 546                        e->delta = NULL;
 547                        break;
 548                default:
 549                        break;
 550                case WRITE_ONE_BREAK:
 551                        e->idx.offset = recursing;
 552                        return WRITE_ONE_BREAK;
 553                }
 554        }
 555
 556        e->idx.offset = *offset;
 557        size = write_object(f, e, *offset);
 558        if (!size) {
 559                e->idx.offset = recursing;
 560                return WRITE_ONE_BREAK;
 561        }
 562        written_list[nr_written++] = &e->idx;
 563
 564        /* make sure off_t is sufficiently large not to wrap */
 565        if (signed_add_overflows(*offset, size))
 566                die("pack too large for current definition of off_t");
 567        *offset += size;
 568        return WRITE_ONE_WRITTEN;
 569}
 570
 571static int mark_tagged(const char *path, const struct object_id *oid, int flag,
 572                       void *cb_data)
 573{
 574        struct object_id peeled;
 575        struct object_entry *entry = packlist_find(&to_pack, oid->hash, NULL);
 576
 577        if (entry)
 578                entry->tagged = 1;
 579        if (!peel_ref(path, &peeled)) {
 580                entry = packlist_find(&to_pack, peeled.hash, NULL);
 581                if (entry)
 582                        entry->tagged = 1;
 583        }
 584        return 0;
 585}
 586
 587static inline void add_to_write_order(struct object_entry **wo,
 588                               unsigned int *endp,
 589                               struct object_entry *e)
 590{
 591        if (e->filled)
 592                return;
 593        wo[(*endp)++] = e;
 594        e->filled = 1;
 595}
 596
 597static void add_descendants_to_write_order(struct object_entry **wo,
 598                                           unsigned int *endp,
 599                                           struct object_entry *e)
 600{
 601        int add_to_order = 1;
 602        while (e) {
 603                if (add_to_order) {
 604                        struct object_entry *s;
 605                        /* add this node... */
 606                        add_to_write_order(wo, endp, e);
 607                        /* all its siblings... */
 608                        for (s = e->delta_sibling; s; s = s->delta_sibling) {
 609                                add_to_write_order(wo, endp, s);
 610                        }
 611                }
 612                /* drop down a level to add left subtree nodes if possible */
 613                if (e->delta_child) {
 614                        add_to_order = 1;
 615                        e = e->delta_child;
 616                } else {
 617                        add_to_order = 0;
 618                        /* our sibling might have some children, it is next */
 619                        if (e->delta_sibling) {
 620                                e = e->delta_sibling;
 621                                continue;
 622                        }
 623                        /* go back to our parent node */
 624                        e = e->delta;
 625                        while (e && !e->delta_sibling) {
 626                                /* we're on the right side of a subtree, keep
 627                                 * going up until we can go right again */
 628                                e = e->delta;
 629                        }
 630                        if (!e) {
 631                                /* done- we hit our original root node */
 632                                return;
 633                        }
 634                        /* pass it off to sibling at this level */
 635                        e = e->delta_sibling;
 636                }
 637        };
 638}
 639
 640static void add_family_to_write_order(struct object_entry **wo,
 641                                      unsigned int *endp,
 642                                      struct object_entry *e)
 643{
 644        struct object_entry *root;
 645
 646        for (root = e; root->delta; root = root->delta)
 647                ; /* nothing */
 648        add_descendants_to_write_order(wo, endp, root);
 649}
 650
 651static struct object_entry **compute_write_order(void)
 652{
 653        unsigned int i, wo_end, last_untagged;
 654
 655        struct object_entry **wo;
 656        struct object_entry *objects = to_pack.objects;
 657
 658        for (i = 0; i < to_pack.nr_objects; i++) {
 659                objects[i].tagged = 0;
 660                objects[i].filled = 0;
 661                objects[i].delta_child = NULL;
 662                objects[i].delta_sibling = NULL;
 663        }
 664
 665        /*
 666         * Fully connect delta_child/delta_sibling network.
 667         * Make sure delta_sibling is sorted in the original
 668         * recency order.
 669         */
 670        for (i = to_pack.nr_objects; i > 0;) {
 671                struct object_entry *e = &objects[--i];
 672                if (!e->delta)
 673                        continue;
 674                /* Mark me as the first child */
 675                e->delta_sibling = e->delta->delta_child;
 676                e->delta->delta_child = e;
 677        }
 678
 679        /*
 680         * Mark objects that are at the tip of tags.
 681         */
 682        for_each_tag_ref(mark_tagged, NULL);
 683
 684        /*
 685         * Give the objects in the original recency order until
 686         * we see a tagged tip.
 687         */
 688        ALLOC_ARRAY(wo, to_pack.nr_objects);
 689        for (i = wo_end = 0; i < to_pack.nr_objects; i++) {
 690                if (objects[i].tagged)
 691                        break;
 692                add_to_write_order(wo, &wo_end, &objects[i]);
 693        }
 694        last_untagged = i;
 695
 696        /*
 697         * Then fill all the tagged tips.
 698         */
 699        for (; i < to_pack.nr_objects; i++) {
 700                if (objects[i].tagged)
 701                        add_to_write_order(wo, &wo_end, &objects[i]);
 702        }
 703
 704        /*
 705         * And then all remaining commits and tags.
 706         */
 707        for (i = last_untagged; i < to_pack.nr_objects; i++) {
 708                if (objects[i].type != OBJ_COMMIT &&
 709                    objects[i].type != OBJ_TAG)
 710                        continue;
 711                add_to_write_order(wo, &wo_end, &objects[i]);
 712        }
 713
 714        /*
 715         * And then all the trees.
 716         */
 717        for (i = last_untagged; i < to_pack.nr_objects; i++) {
 718                if (objects[i].type != OBJ_TREE)
 719                        continue;
 720                add_to_write_order(wo, &wo_end, &objects[i]);
 721        }
 722
 723        /*
 724         * Finally all the rest in really tight order
 725         */
 726        for (i = last_untagged; i < to_pack.nr_objects; i++) {
 727                if (!objects[i].filled)
 728                        add_family_to_write_order(wo, &wo_end, &objects[i]);
 729        }
 730
 731        if (wo_end != to_pack.nr_objects)
 732                die("ordered %u objects, expected %"PRIu32, wo_end, to_pack.nr_objects);
 733
 734        return wo;
 735}
 736
 737static off_t write_reused_pack(struct sha1file *f)
 738{
 739        unsigned char buffer[8192];
 740        off_t to_write, total;
 741        int fd;
 742
 743        if (!is_pack_valid(reuse_packfile))
 744                die("packfile is invalid: %s", reuse_packfile->pack_name);
 745
 746        fd = git_open(reuse_packfile->pack_name);
 747        if (fd < 0)
 748                die_errno("unable to open packfile for reuse: %s",
 749                          reuse_packfile->pack_name);
 750
 751        if (lseek(fd, sizeof(struct pack_header), SEEK_SET) == -1)
 752                die_errno("unable to seek in reused packfile");
 753
 754        if (reuse_packfile_offset < 0)
 755                reuse_packfile_offset = reuse_packfile->pack_size - 20;
 756
 757        total = to_write = reuse_packfile_offset - sizeof(struct pack_header);
 758
 759        while (to_write) {
 760                int read_pack = xread(fd, buffer, sizeof(buffer));
 761
 762                if (read_pack <= 0)
 763                        die_errno("unable to read from reused packfile");
 764
 765                if (read_pack > to_write)
 766                        read_pack = to_write;
 767
 768                sha1write(f, buffer, read_pack);
 769                to_write -= read_pack;
 770
 771                /*
 772                 * We don't know the actual number of objects written,
 773                 * only how many bytes written, how many bytes total, and
 774                 * how many objects total. So we can fake it by pretending all
 775                 * objects we are writing are the same size. This gives us a
 776                 * smooth progress meter, and at the end it matches the true
 777                 * answer.
 778                 */
 779                written = reuse_packfile_objects *
 780                                (((double)(total - to_write)) / total);
 781                display_progress(progress_state, written);
 782        }
 783
 784        close(fd);
 785        written = reuse_packfile_objects;
 786        display_progress(progress_state, written);
 787        return reuse_packfile_offset - sizeof(struct pack_header);
 788}
 789
 790static const char no_split_warning[] = N_(
 791"disabling bitmap writing, packs are split due to pack.packSizeLimit"
 792);
 793
 794static void write_pack_file(void)
 795{
 796        uint32_t i = 0, j;
 797        struct sha1file *f;
 798        off_t offset;
 799        uint32_t nr_remaining = nr_result;
 800        time_t last_mtime = 0;
 801        struct object_entry **write_order;
 802
 803        if (progress > pack_to_stdout)
 804                progress_state = start_progress(_("Writing objects"), nr_result);
 805        ALLOC_ARRAY(written_list, to_pack.nr_objects);
 806        write_order = compute_write_order();
 807
 808        do {
 809                struct object_id oid;
 810                char *pack_tmp_name = NULL;
 811
 812                if (pack_to_stdout)
 813                        f = sha1fd_throughput(1, "<stdout>", progress_state);
 814                else
 815                        f = create_tmp_packfile(&pack_tmp_name);
 816
 817                offset = write_pack_header(f, nr_remaining);
 818
 819                if (reuse_packfile) {
 820                        off_t packfile_size;
 821                        assert(pack_to_stdout);
 822
 823                        packfile_size = write_reused_pack(f);
 824                        offset += packfile_size;
 825                }
 826
 827                nr_written = 0;
 828                for (; i < to_pack.nr_objects; i++) {
 829                        struct object_entry *e = write_order[i];
 830                        if (write_one(f, e, &offset) == WRITE_ONE_BREAK)
 831                                break;
 832                        display_progress(progress_state, written);
 833                }
 834
 835                /*
 836                 * Did we write the wrong # entries in the header?
 837                 * If so, rewrite it like in fast-import
 838                 */
 839                if (pack_to_stdout) {
 840                        sha1close(f, oid.hash, CSUM_CLOSE);
 841                } else if (nr_written == nr_remaining) {
 842                        sha1close(f, oid.hash, CSUM_FSYNC);
 843                } else {
 844                        int fd = sha1close(f, oid.hash, 0);
 845                        fixup_pack_header_footer(fd, oid.hash, pack_tmp_name,
 846                                                 nr_written, oid.hash, offset);
 847                        close(fd);
 848                        if (write_bitmap_index) {
 849                                warning(_(no_split_warning));
 850                                write_bitmap_index = 0;
 851                        }
 852                }
 853
 854                if (!pack_to_stdout) {
 855                        struct stat st;
 856                        struct strbuf tmpname = STRBUF_INIT;
 857
 858                        /*
 859                         * Packs are runtime accessed in their mtime
 860                         * order since newer packs are more likely to contain
 861                         * younger objects.  So if we are creating multiple
 862                         * packs then we should modify the mtime of later ones
 863                         * to preserve this property.
 864                         */
 865                        if (stat(pack_tmp_name, &st) < 0) {
 866                                warning_errno("failed to stat %s", pack_tmp_name);
 867                        } else if (!last_mtime) {
 868                                last_mtime = st.st_mtime;
 869                        } else {
 870                                struct utimbuf utb;
 871                                utb.actime = st.st_atime;
 872                                utb.modtime = --last_mtime;
 873                                if (utime(pack_tmp_name, &utb) < 0)
 874                                        warning_errno("failed utime() on %s", pack_tmp_name);
 875                        }
 876
 877                        strbuf_addf(&tmpname, "%s-", base_name);
 878
 879                        if (write_bitmap_index) {
 880                                bitmap_writer_set_checksum(oid.hash);
 881                                bitmap_writer_build_type_index(written_list, nr_written);
 882                        }
 883
 884                        finish_tmp_packfile(&tmpname, pack_tmp_name,
 885                                            written_list, nr_written,
 886                                            &pack_idx_opts, oid.hash);
 887
 888                        if (write_bitmap_index) {
 889                                strbuf_addf(&tmpname, "%s.bitmap", oid_to_hex(&oid));
 890
 891                                stop_progress(&progress_state);
 892
 893                                bitmap_writer_show_progress(progress);
 894                                bitmap_writer_reuse_bitmaps(&to_pack);
 895                                bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
 896                                bitmap_writer_build(&to_pack);
 897                                bitmap_writer_finish(written_list, nr_written,
 898                                                     tmpname.buf, write_bitmap_options);
 899                                write_bitmap_index = 0;
 900                        }
 901
 902                        strbuf_release(&tmpname);
 903                        free(pack_tmp_name);
 904                        puts(oid_to_hex(&oid));
 905                }
 906
 907                /* mark written objects as written to previous pack */
 908                for (j = 0; j < nr_written; j++) {
 909                        written_list[j]->offset = (off_t)-1;
 910                }
 911                nr_remaining -= nr_written;
 912        } while (nr_remaining && i < to_pack.nr_objects);
 913
 914        free(written_list);
 915        free(write_order);
 916        stop_progress(&progress_state);
 917        if (written != nr_result)
 918                die("wrote %"PRIu32" objects while expecting %"PRIu32,
 919                        written, nr_result);
 920}
 921
 922static int no_try_delta(const char *path)
 923{
 924        static struct attr_check *check;
 925
 926        if (!check)
 927                check = attr_check_initl("delta", NULL);
 928        if (git_check_attr(path, check))
 929                return 0;
 930        if (ATTR_FALSE(check->items[0].value))
 931                return 1;
 932        return 0;
 933}
 934
 935/*
 936 * When adding an object, check whether we have already added it
 937 * to our packing list. If so, we can skip. However, if we are
 938 * being asked to excludei t, but the previous mention was to include
 939 * it, make sure to adjust its flags and tweak our numbers accordingly.
 940 *
 941 * As an optimization, we pass out the index position where we would have
 942 * found the item, since that saves us from having to look it up again a
 943 * few lines later when we want to add the new entry.
 944 */
 945static int have_duplicate_entry(const struct object_id *oid,
 946                                int exclude,
 947                                uint32_t *index_pos)
 948{
 949        struct object_entry *entry;
 950
 951        entry = packlist_find(&to_pack, oid->hash, index_pos);
 952        if (!entry)
 953                return 0;
 954
 955        if (exclude) {
 956                if (!entry->preferred_base)
 957                        nr_result--;
 958                entry->preferred_base = 1;
 959        }
 960
 961        return 1;
 962}
 963
 964static int want_found_object(int exclude, struct packed_git *p)
 965{
 966        if (exclude)
 967                return 1;
 968        if (incremental)
 969                return 0;
 970
 971        /*
 972         * When asked to do --local (do not include an object that appears in a
 973         * pack we borrow from elsewhere) or --honor-pack-keep (do not include
 974         * an object that appears in a pack marked with .keep), finding a pack
 975         * that matches the criteria is sufficient for us to decide to omit it.
 976         * However, even if this pack does not satisfy the criteria, we need to
 977         * make sure no copy of this object appears in _any_ pack that makes us
 978         * to omit the object, so we need to check all the packs.
 979         *
 980         * We can however first check whether these options can possible matter;
 981         * if they do not matter we know we want the object in generated pack.
 982         * Otherwise, we signal "-1" at the end to tell the caller that we do
 983         * not know either way, and it needs to check more packs.
 984         */
 985        if (!ignore_packed_keep &&
 986            (!local || !have_non_local_packs))
 987                return 1;
 988
 989        if (local && !p->pack_local)
 990                return 0;
 991        if (ignore_packed_keep && p->pack_local && p->pack_keep)
 992                return 0;
 993
 994        /* we don't know yet; keep looking for more packs */
 995        return -1;
 996}
 997
 998/*
 999 * Check whether we want the object in the pack (e.g., we do not want
1000 * objects found in non-local stores if the "--local" option was used).
1001 *
1002 * If the caller already knows an existing pack it wants to take the object
1003 * from, that is passed in *found_pack and *found_offset; otherwise this
1004 * function finds if there is any pack that has the object and returns the pack
1005 * and its offset in these variables.
1006 */
1007static int want_object_in_pack(const struct object_id *oid,
1008                               int exclude,
1009                               struct packed_git **found_pack,
1010                               off_t *found_offset)
1011{
1012        int want;
1013        struct list_head *pos;
1014
1015        if (!exclude && local && has_loose_object_nonlocal(oid->hash))
1016                return 0;
1017
1018        /*
1019         * If we already know the pack object lives in, start checks from that
1020         * pack - in the usual case when neither --local was given nor .keep files
1021         * are present we will determine the answer right now.
1022         */
1023        if (*found_pack) {
1024                want = want_found_object(exclude, *found_pack);
1025                if (want != -1)
1026                        return want;
1027        }
1028
1029        list_for_each(pos, &packed_git_mru) {
1030                struct packed_git *p = list_entry(pos, struct packed_git, mru);
1031                off_t offset;
1032
1033                if (p == *found_pack)
1034                        offset = *found_offset;
1035                else
1036                        offset = find_pack_entry_one(oid->hash, p);
1037
1038                if (offset) {
1039                        if (!*found_pack) {
1040                                if (!is_pack_valid(p))
1041                                        continue;
1042                                *found_offset = offset;
1043                                *found_pack = p;
1044                        }
1045                        want = want_found_object(exclude, p);
1046                        if (!exclude && want > 0)
1047                                list_move(&p->mru, &packed_git_mru);
1048                        if (want != -1)
1049                                return want;
1050                }
1051        }
1052
1053        return 1;
1054}
1055
1056static void create_object_entry(const struct object_id *oid,
1057                                enum object_type type,
1058                                uint32_t hash,
1059                                int exclude,
1060                                int no_try_delta,
1061                                uint32_t index_pos,
1062                                struct packed_git *found_pack,
1063                                off_t found_offset)
1064{
1065        struct object_entry *entry;
1066
1067        entry = packlist_alloc(&to_pack, oid->hash, index_pos);
1068        entry->hash = hash;
1069        if (type)
1070                entry->type = type;
1071        if (exclude)
1072                entry->preferred_base = 1;
1073        else
1074                nr_result++;
1075        if (found_pack) {
1076                entry->in_pack = found_pack;
1077                entry->in_pack_offset = found_offset;
1078        }
1079
1080        entry->no_try_delta = no_try_delta;
1081}
1082
1083static const char no_closure_warning[] = N_(
1084"disabling bitmap writing, as some objects are not being packed"
1085);
1086
1087static int add_object_entry(const struct object_id *oid, enum object_type type,
1088                            const char *name, int exclude)
1089{
1090        struct packed_git *found_pack = NULL;
1091        off_t found_offset = 0;
1092        uint32_t index_pos;
1093
1094        if (have_duplicate_entry(oid, exclude, &index_pos))
1095                return 0;
1096
1097        if (!want_object_in_pack(oid, exclude, &found_pack, &found_offset)) {
1098                /* The pack is missing an object, so it will not have closure */
1099                if (write_bitmap_index) {
1100                        warning(_(no_closure_warning));
1101                        write_bitmap_index = 0;
1102                }
1103                return 0;
1104        }
1105
1106        create_object_entry(oid, type, pack_name_hash(name),
1107                            exclude, name && no_try_delta(name),
1108                            index_pos, found_pack, found_offset);
1109
1110        display_progress(progress_state, nr_result);
1111        return 1;
1112}
1113
1114static int add_object_entry_from_bitmap(const struct object_id *oid,
1115                                        enum object_type type,
1116                                        int flags, uint32_t name_hash,
1117                                        struct packed_git *pack, off_t offset)
1118{
1119        uint32_t index_pos;
1120
1121        if (have_duplicate_entry(oid, 0, &index_pos))
1122                return 0;
1123
1124        if (!want_object_in_pack(oid, 0, &pack, &offset))
1125                return 0;
1126
1127        create_object_entry(oid, type, name_hash, 0, 0, index_pos, pack, offset);
1128
1129        display_progress(progress_state, nr_result);
1130        return 1;
1131}
1132
1133struct pbase_tree_cache {
1134        struct object_id oid;
1135        int ref;
1136        int temporary;
1137        void *tree_data;
1138        unsigned long tree_size;
1139};
1140
1141static struct pbase_tree_cache *(pbase_tree_cache[256]);
1142static int pbase_tree_cache_ix(const struct object_id *oid)
1143{
1144        return oid->hash[0] % ARRAY_SIZE(pbase_tree_cache);
1145}
1146static int pbase_tree_cache_ix_incr(int ix)
1147{
1148        return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
1149}
1150
1151static struct pbase_tree {
1152        struct pbase_tree *next;
1153        /* This is a phony "cache" entry; we are not
1154         * going to evict it or find it through _get()
1155         * mechanism -- this is for the toplevel node that
1156         * would almost always change with any commit.
1157         */
1158        struct pbase_tree_cache pcache;
1159} *pbase_tree;
1160
1161static struct pbase_tree_cache *pbase_tree_get(const struct object_id *oid)
1162{
1163        struct pbase_tree_cache *ent, *nent;
1164        void *data;
1165        unsigned long size;
1166        enum object_type type;
1167        int neigh;
1168        int my_ix = pbase_tree_cache_ix(oid);
1169        int available_ix = -1;
1170
1171        /* pbase-tree-cache acts as a limited hashtable.
1172         * your object will be found at your index or within a few
1173         * slots after that slot if it is cached.
1174         */
1175        for (neigh = 0; neigh < 8; neigh++) {
1176                ent = pbase_tree_cache[my_ix];
1177                if (ent && !oidcmp(&ent->oid, oid)) {
1178                        ent->ref++;
1179                        return ent;
1180                }
1181                else if (((available_ix < 0) && (!ent || !ent->ref)) ||
1182                         ((0 <= available_ix) &&
1183                          (!ent && pbase_tree_cache[available_ix])))
1184                        available_ix = my_ix;
1185                if (!ent)
1186                        break;
1187                my_ix = pbase_tree_cache_ix_incr(my_ix);
1188        }
1189
1190        /* Did not find one.  Either we got a bogus request or
1191         * we need to read and perhaps cache.
1192         */
1193        data = read_sha1_file(oid->hash, &type, &size);
1194        if (!data)
1195                return NULL;
1196        if (type != OBJ_TREE) {
1197                free(data);
1198                return NULL;
1199        }
1200
1201        /* We need to either cache or return a throwaway copy */
1202
1203        if (available_ix < 0)
1204                ent = NULL;
1205        else {
1206                ent = pbase_tree_cache[available_ix];
1207                my_ix = available_ix;
1208        }
1209
1210        if (!ent) {
1211                nent = xmalloc(sizeof(*nent));
1212                nent->temporary = (available_ix < 0);
1213        }
1214        else {
1215                /* evict and reuse */
1216                free(ent->tree_data);
1217                nent = ent;
1218        }
1219        oidcpy(&nent->oid, oid);
1220        nent->tree_data = data;
1221        nent->tree_size = size;
1222        nent->ref = 1;
1223        if (!nent->temporary)
1224                pbase_tree_cache[my_ix] = nent;
1225        return nent;
1226}
1227
1228static void pbase_tree_put(struct pbase_tree_cache *cache)
1229{
1230        if (!cache->temporary) {
1231                cache->ref--;
1232                return;
1233        }
1234        free(cache->tree_data);
1235        free(cache);
1236}
1237
1238static int name_cmp_len(const char *name)
1239{
1240        int i;
1241        for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
1242                ;
1243        return i;
1244}
1245
1246static void add_pbase_object(struct tree_desc *tree,
1247                             const char *name,
1248                             int cmplen,
1249                             const char *fullname)
1250{
1251        struct name_entry entry;
1252        int cmp;
1253
1254        while (tree_entry(tree,&entry)) {
1255                if (S_ISGITLINK(entry.mode))
1256                        continue;
1257                cmp = tree_entry_len(&entry) != cmplen ? 1 :
1258                      memcmp(name, entry.path, cmplen);
1259                if (cmp > 0)
1260                        continue;
1261                if (cmp < 0)
1262                        return;
1263                if (name[cmplen] != '/') {
1264                        add_object_entry(entry.oid,
1265                                         object_type(entry.mode),
1266                                         fullname, 1);
1267                        return;
1268                }
1269                if (S_ISDIR(entry.mode)) {
1270                        struct tree_desc sub;
1271                        struct pbase_tree_cache *tree;
1272                        const char *down = name+cmplen+1;
1273                        int downlen = name_cmp_len(down);
1274
1275                        tree = pbase_tree_get(entry.oid);
1276                        if (!tree)
1277                                return;
1278                        init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1279
1280                        add_pbase_object(&sub, down, downlen, fullname);
1281                        pbase_tree_put(tree);
1282                }
1283        }
1284}
1285
1286static unsigned *done_pbase_paths;
1287static int done_pbase_paths_num;
1288static int done_pbase_paths_alloc;
1289static int done_pbase_path_pos(unsigned hash)
1290{
1291        int lo = 0;
1292        int hi = done_pbase_paths_num;
1293        while (lo < hi) {
1294                int mi = lo + (hi - lo) / 2;
1295                if (done_pbase_paths[mi] == hash)
1296                        return mi;
1297                if (done_pbase_paths[mi] < hash)
1298                        hi = mi;
1299                else
1300                        lo = mi + 1;
1301        }
1302        return -lo-1;
1303}
1304
1305static int check_pbase_path(unsigned hash)
1306{
1307        int pos = done_pbase_path_pos(hash);
1308        if (0 <= pos)
1309                return 1;
1310        pos = -pos - 1;
1311        ALLOC_GROW(done_pbase_paths,
1312                   done_pbase_paths_num + 1,
1313                   done_pbase_paths_alloc);
1314        done_pbase_paths_num++;
1315        if (pos < done_pbase_paths_num)
1316                MOVE_ARRAY(done_pbase_paths + pos + 1, done_pbase_paths + pos,
1317                           done_pbase_paths_num - pos - 1);
1318        done_pbase_paths[pos] = hash;
1319        return 0;
1320}
1321
1322static void add_preferred_base_object(const char *name)
1323{
1324        struct pbase_tree *it;
1325        int cmplen;
1326        unsigned hash = pack_name_hash(name);
1327
1328        if (!num_preferred_base || check_pbase_path(hash))
1329                return;
1330
1331        cmplen = name_cmp_len(name);
1332        for (it = pbase_tree; it; it = it->next) {
1333                if (cmplen == 0) {
1334                        add_object_entry(&it->pcache.oid, OBJ_TREE, NULL, 1);
1335                }
1336                else {
1337                        struct tree_desc tree;
1338                        init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1339                        add_pbase_object(&tree, name, cmplen, name);
1340                }
1341        }
1342}
1343
1344static void add_preferred_base(struct object_id *oid)
1345{
1346        struct pbase_tree *it;
1347        void *data;
1348        unsigned long size;
1349        struct object_id tree_oid;
1350
1351        if (window <= num_preferred_base++)
1352                return;
1353
1354        data = read_object_with_reference(oid->hash, tree_type, &size, tree_oid.hash);
1355        if (!data)
1356                return;
1357
1358        for (it = pbase_tree; it; it = it->next) {
1359                if (!oidcmp(&it->pcache.oid, &tree_oid)) {
1360                        free(data);
1361                        return;
1362                }
1363        }
1364
1365        it = xcalloc(1, sizeof(*it));
1366        it->next = pbase_tree;
1367        pbase_tree = it;
1368
1369        oidcpy(&it->pcache.oid, &tree_oid);
1370        it->pcache.tree_data = data;
1371        it->pcache.tree_size = size;
1372}
1373
1374static void cleanup_preferred_base(void)
1375{
1376        struct pbase_tree *it;
1377        unsigned i;
1378
1379        it = pbase_tree;
1380        pbase_tree = NULL;
1381        while (it) {
1382                struct pbase_tree *this = it;
1383                it = this->next;
1384                free(this->pcache.tree_data);
1385                free(this);
1386        }
1387
1388        for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1389                if (!pbase_tree_cache[i])
1390                        continue;
1391                free(pbase_tree_cache[i]->tree_data);
1392                FREE_AND_NULL(pbase_tree_cache[i]);
1393        }
1394
1395        FREE_AND_NULL(done_pbase_paths);
1396        done_pbase_paths_num = done_pbase_paths_alloc = 0;
1397}
1398
1399static void check_object(struct object_entry *entry)
1400{
1401        if (entry->in_pack) {
1402                struct packed_git *p = entry->in_pack;
1403                struct pack_window *w_curs = NULL;
1404                const unsigned char *base_ref = NULL;
1405                struct object_entry *base_entry;
1406                unsigned long used, used_0;
1407                unsigned long avail;
1408                off_t ofs;
1409                unsigned char *buf, c;
1410
1411                buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1412
1413                /*
1414                 * We want in_pack_type even if we do not reuse delta
1415                 * since non-delta representations could still be reused.
1416                 */
1417                used = unpack_object_header_buffer(buf, avail,
1418                                                   &entry->in_pack_type,
1419                                                   &entry->size);
1420                if (used == 0)
1421                        goto give_up;
1422
1423                /*
1424                 * Determine if this is a delta and if so whether we can
1425                 * reuse it or not.  Otherwise let's find out as cheaply as
1426                 * possible what the actual type and size for this object is.
1427                 */
1428                switch (entry->in_pack_type) {
1429                default:
1430                        /* Not a delta hence we've already got all we need. */
1431                        entry->type = entry->in_pack_type;
1432                        entry->in_pack_header_size = used;
1433                        if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1434                                goto give_up;
1435                        unuse_pack(&w_curs);
1436                        return;
1437                case OBJ_REF_DELTA:
1438                        if (reuse_delta && !entry->preferred_base)
1439                                base_ref = use_pack(p, &w_curs,
1440                                                entry->in_pack_offset + used, NULL);
1441                        entry->in_pack_header_size = used + 20;
1442                        break;
1443                case OBJ_OFS_DELTA:
1444                        buf = use_pack(p, &w_curs,
1445                                       entry->in_pack_offset + used, NULL);
1446                        used_0 = 0;
1447                        c = buf[used_0++];
1448                        ofs = c & 127;
1449                        while (c & 128) {
1450                                ofs += 1;
1451                                if (!ofs || MSB(ofs, 7)) {
1452                                        error("delta base offset overflow in pack for %s",
1453                                              oid_to_hex(&entry->idx.oid));
1454                                        goto give_up;
1455                                }
1456                                c = buf[used_0++];
1457                                ofs = (ofs << 7) + (c & 127);
1458                        }
1459                        ofs = entry->in_pack_offset - ofs;
1460                        if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1461                                error("delta base offset out of bound for %s",
1462                                      oid_to_hex(&entry->idx.oid));
1463                                goto give_up;
1464                        }
1465                        if (reuse_delta && !entry->preferred_base) {
1466                                struct revindex_entry *revidx;
1467                                revidx = find_pack_revindex(p, ofs);
1468                                if (!revidx)
1469                                        goto give_up;
1470                                base_ref = nth_packed_object_sha1(p, revidx->nr);
1471                        }
1472                        entry->in_pack_header_size = used + used_0;
1473                        break;
1474                }
1475
1476                if (base_ref && (base_entry = packlist_find(&to_pack, base_ref, NULL))) {
1477                        /*
1478                         * If base_ref was set above that means we wish to
1479                         * reuse delta data, and we even found that base
1480                         * in the list of objects we want to pack. Goodie!
1481                         *
1482                         * Depth value does not matter - find_deltas() will
1483                         * never consider reused delta as the base object to
1484                         * deltify other objects against, in order to avoid
1485                         * circular deltas.
1486                         */
1487                        entry->type = entry->in_pack_type;
1488                        entry->delta = base_entry;
1489                        entry->delta_size = entry->size;
1490                        entry->delta_sibling = base_entry->delta_child;
1491                        base_entry->delta_child = entry;
1492                        unuse_pack(&w_curs);
1493                        return;
1494                }
1495
1496                if (entry->type) {
1497                        /*
1498                         * This must be a delta and we already know what the
1499                         * final object type is.  Let's extract the actual
1500                         * object size from the delta header.
1501                         */
1502                        entry->size = get_size_from_delta(p, &w_curs,
1503                                        entry->in_pack_offset + entry->in_pack_header_size);
1504                        if (entry->size == 0)
1505                                goto give_up;
1506                        unuse_pack(&w_curs);
1507                        return;
1508                }
1509
1510                /*
1511                 * No choice but to fall back to the recursive delta walk
1512                 * with sha1_object_info() to find about the object type
1513                 * at this point...
1514                 */
1515                give_up:
1516                unuse_pack(&w_curs);
1517        }
1518
1519        entry->type = sha1_object_info(entry->idx.oid.hash, &entry->size);
1520        /*
1521         * The error condition is checked in prepare_pack().  This is
1522         * to permit a missing preferred base object to be ignored
1523         * as a preferred base.  Doing so can result in a larger
1524         * pack file, but the transfer will still take place.
1525         */
1526}
1527
1528static int pack_offset_sort(const void *_a, const void *_b)
1529{
1530        const struct object_entry *a = *(struct object_entry **)_a;
1531        const struct object_entry *b = *(struct object_entry **)_b;
1532
1533        /* avoid filesystem trashing with loose objects */
1534        if (!a->in_pack && !b->in_pack)
1535                return oidcmp(&a->idx.oid, &b->idx.oid);
1536
1537        if (a->in_pack < b->in_pack)
1538                return -1;
1539        if (a->in_pack > b->in_pack)
1540                return 1;
1541        return a->in_pack_offset < b->in_pack_offset ? -1 :
1542                        (a->in_pack_offset > b->in_pack_offset);
1543}
1544
1545/*
1546 * Drop an on-disk delta we were planning to reuse. Naively, this would
1547 * just involve blanking out the "delta" field, but we have to deal
1548 * with some extra book-keeping:
1549 *
1550 *   1. Removing ourselves from the delta_sibling linked list.
1551 *
1552 *   2. Updating our size/type to the non-delta representation. These were
1553 *      either not recorded initially (size) or overwritten with the delta type
1554 *      (type) when check_object() decided to reuse the delta.
1555 *
1556 *   3. Resetting our delta depth, as we are now a base object.
1557 */
1558static void drop_reused_delta(struct object_entry *entry)
1559{
1560        struct object_entry **p = &entry->delta->delta_child;
1561        struct object_info oi = OBJECT_INFO_INIT;
1562
1563        while (*p) {
1564                if (*p == entry)
1565                        *p = (*p)->delta_sibling;
1566                else
1567                        p = &(*p)->delta_sibling;
1568        }
1569        entry->delta = NULL;
1570        entry->depth = 0;
1571
1572        oi.sizep = &entry->size;
1573        oi.typep = &entry->type;
1574        if (packed_object_info(entry->in_pack, entry->in_pack_offset, &oi) < 0) {
1575                /*
1576                 * We failed to get the info from this pack for some reason;
1577                 * fall back to sha1_object_info, which may find another copy.
1578                 * And if that fails, the error will be recorded in entry->type
1579                 * and dealt with in prepare_pack().
1580                 */
1581                entry->type = sha1_object_info(entry->idx.oid.hash,
1582                                               &entry->size);
1583        }
1584}
1585
1586/*
1587 * Follow the chain of deltas from this entry onward, throwing away any links
1588 * that cause us to hit a cycle (as determined by the DFS state flags in
1589 * the entries).
1590 *
1591 * We also detect too-long reused chains that would violate our --depth
1592 * limit.
1593 */
1594static void break_delta_chains(struct object_entry *entry)
1595{
1596        /*
1597         * The actual depth of each object we will write is stored as an int,
1598         * as it cannot exceed our int "depth" limit. But before we break
1599         * changes based no that limit, we may potentially go as deep as the
1600         * number of objects, which is elsewhere bounded to a uint32_t.
1601         */
1602        uint32_t total_depth;
1603        struct object_entry *cur, *next;
1604
1605        for (cur = entry, total_depth = 0;
1606             cur;
1607             cur = cur->delta, total_depth++) {
1608                if (cur->dfs_state == DFS_DONE) {
1609                        /*
1610                         * We've already seen this object and know it isn't
1611                         * part of a cycle. We do need to append its depth
1612                         * to our count.
1613                         */
1614                        total_depth += cur->depth;
1615                        break;
1616                }
1617
1618                /*
1619                 * We break cycles before looping, so an ACTIVE state (or any
1620                 * other cruft which made its way into the state variable)
1621                 * is a bug.
1622                 */
1623                if (cur->dfs_state != DFS_NONE)
1624                        die("BUG: confusing delta dfs state in first pass: %d",
1625                            cur->dfs_state);
1626
1627                /*
1628                 * Now we know this is the first time we've seen the object. If
1629                 * it's not a delta, we're done traversing, but we'll mark it
1630                 * done to save time on future traversals.
1631                 */
1632                if (!cur->delta) {
1633                        cur->dfs_state = DFS_DONE;
1634                        break;
1635                }
1636
1637                /*
1638                 * Mark ourselves as active and see if the next step causes
1639                 * us to cycle to another active object. It's important to do
1640                 * this _before_ we loop, because it impacts where we make the
1641                 * cut, and thus how our total_depth counter works.
1642                 * E.g., We may see a partial loop like:
1643                 *
1644                 *   A -> B -> C -> D -> B
1645                 *
1646                 * Cutting B->C breaks the cycle. But now the depth of A is
1647                 * only 1, and our total_depth counter is at 3. The size of the
1648                 * error is always one less than the size of the cycle we
1649                 * broke. Commits C and D were "lost" from A's chain.
1650                 *
1651                 * If we instead cut D->B, then the depth of A is correct at 3.
1652                 * We keep all commits in the chain that we examined.
1653                 */
1654                cur->dfs_state = DFS_ACTIVE;
1655                if (cur->delta->dfs_state == DFS_ACTIVE) {
1656                        drop_reused_delta(cur);
1657                        cur->dfs_state = DFS_DONE;
1658                        break;
1659                }
1660        }
1661
1662        /*
1663         * And now that we've gone all the way to the bottom of the chain, we
1664         * need to clear the active flags and set the depth fields as
1665         * appropriate. Unlike the loop above, which can quit when it drops a
1666         * delta, we need to keep going to look for more depth cuts. So we need
1667         * an extra "next" pointer to keep going after we reset cur->delta.
1668         */
1669        for (cur = entry; cur; cur = next) {
1670                next = cur->delta;
1671
1672                /*
1673                 * We should have a chain of zero or more ACTIVE states down to
1674                 * a final DONE. We can quit after the DONE, because either it
1675                 * has no bases, or we've already handled them in a previous
1676                 * call.
1677                 */
1678                if (cur->dfs_state == DFS_DONE)
1679                        break;
1680                else if (cur->dfs_state != DFS_ACTIVE)
1681                        die("BUG: confusing delta dfs state in second pass: %d",
1682                            cur->dfs_state);
1683
1684                /*
1685                 * If the total_depth is more than depth, then we need to snip
1686                 * the chain into two or more smaller chains that don't exceed
1687                 * the maximum depth. Most of the resulting chains will contain
1688                 * (depth + 1) entries (i.e., depth deltas plus one base), and
1689                 * the last chain (i.e., the one containing entry) will contain
1690                 * whatever entries are left over, namely
1691                 * (total_depth % (depth + 1)) of them.
1692                 *
1693                 * Since we are iterating towards decreasing depth, we need to
1694                 * decrement total_depth as we go, and we need to write to the
1695                 * entry what its final depth will be after all of the
1696                 * snipping. Since we're snipping into chains of length (depth
1697                 * + 1) entries, the final depth of an entry will be its
1698                 * original depth modulo (depth + 1). Any time we encounter an
1699                 * entry whose final depth is supposed to be zero, we snip it
1700                 * from its delta base, thereby making it so.
1701                 */
1702                cur->depth = (total_depth--) % (depth + 1);
1703                if (!cur->depth)
1704                        drop_reused_delta(cur);
1705
1706                cur->dfs_state = DFS_DONE;
1707        }
1708}
1709
1710static void get_object_details(void)
1711{
1712        uint32_t i;
1713        struct object_entry **sorted_by_offset;
1714
1715        sorted_by_offset = xcalloc(to_pack.nr_objects, sizeof(struct object_entry *));
1716        for (i = 0; i < to_pack.nr_objects; i++)
1717                sorted_by_offset[i] = to_pack.objects + i;
1718        QSORT(sorted_by_offset, to_pack.nr_objects, pack_offset_sort);
1719
1720        for (i = 0; i < to_pack.nr_objects; i++) {
1721                struct object_entry *entry = sorted_by_offset[i];
1722                check_object(entry);
1723                if (big_file_threshold < entry->size)
1724                        entry->no_try_delta = 1;
1725        }
1726
1727        /*
1728         * This must happen in a second pass, since we rely on the delta
1729         * information for the whole list being completed.
1730         */
1731        for (i = 0; i < to_pack.nr_objects; i++)
1732                break_delta_chains(&to_pack.objects[i]);
1733
1734        free(sorted_by_offset);
1735}
1736
1737/*
1738 * We search for deltas in a list sorted by type, by filename hash, and then
1739 * by size, so that we see progressively smaller and smaller files.
1740 * That's because we prefer deltas to be from the bigger file
1741 * to the smaller -- deletes are potentially cheaper, but perhaps
1742 * more importantly, the bigger file is likely the more recent
1743 * one.  The deepest deltas are therefore the oldest objects which are
1744 * less susceptible to be accessed often.
1745 */
1746static int type_size_sort(const void *_a, const void *_b)
1747{
1748        const struct object_entry *a = *(struct object_entry **)_a;
1749        const struct object_entry *b = *(struct object_entry **)_b;
1750
1751        if (a->type > b->type)
1752                return -1;
1753        if (a->type < b->type)
1754                return 1;
1755        if (a->hash > b->hash)
1756                return -1;
1757        if (a->hash < b->hash)
1758                return 1;
1759        if (a->preferred_base > b->preferred_base)
1760                return -1;
1761        if (a->preferred_base < b->preferred_base)
1762                return 1;
1763        if (a->size > b->size)
1764                return -1;
1765        if (a->size < b->size)
1766                return 1;
1767        return a < b ? -1 : (a > b);  /* newest first */
1768}
1769
1770struct unpacked {
1771        struct object_entry *entry;
1772        void *data;
1773        struct delta_index *index;
1774        unsigned depth;
1775};
1776
1777static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1778                           unsigned long delta_size)
1779{
1780        if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1781                return 0;
1782
1783        if (delta_size < cache_max_small_delta_size)
1784                return 1;
1785
1786        /* cache delta, if objects are large enough compared to delta size */
1787        if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1788                return 1;
1789
1790        return 0;
1791}
1792
1793#ifndef NO_PTHREADS
1794
1795static pthread_mutex_t read_mutex;
1796#define read_lock()             pthread_mutex_lock(&read_mutex)
1797#define read_unlock()           pthread_mutex_unlock(&read_mutex)
1798
1799static pthread_mutex_t cache_mutex;
1800#define cache_lock()            pthread_mutex_lock(&cache_mutex)
1801#define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1802
1803static pthread_mutex_t progress_mutex;
1804#define progress_lock()         pthread_mutex_lock(&progress_mutex)
1805#define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1806
1807#else
1808
1809#define read_lock()             (void)0
1810#define read_unlock()           (void)0
1811#define cache_lock()            (void)0
1812#define cache_unlock()          (void)0
1813#define progress_lock()         (void)0
1814#define progress_unlock()       (void)0
1815
1816#endif
1817
1818static int try_delta(struct unpacked *trg, struct unpacked *src,
1819                     unsigned max_depth, unsigned long *mem_usage)
1820{
1821        struct object_entry *trg_entry = trg->entry;
1822        struct object_entry *src_entry = src->entry;
1823        unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1824        unsigned ref_depth;
1825        enum object_type type;
1826        void *delta_buf;
1827
1828        /* Don't bother doing diffs between different types */
1829        if (trg_entry->type != src_entry->type)
1830                return -1;
1831
1832        /*
1833         * We do not bother to try a delta that we discarded on an
1834         * earlier try, but only when reusing delta data.  Note that
1835         * src_entry that is marked as the preferred_base should always
1836         * be considered, as even if we produce a suboptimal delta against
1837         * it, we will still save the transfer cost, as we already know
1838         * the other side has it and we won't send src_entry at all.
1839         */
1840        if (reuse_delta && trg_entry->in_pack &&
1841            trg_entry->in_pack == src_entry->in_pack &&
1842            !src_entry->preferred_base &&
1843            trg_entry->in_pack_type != OBJ_REF_DELTA &&
1844            trg_entry->in_pack_type != OBJ_OFS_DELTA)
1845                return 0;
1846
1847        /* Let's not bust the allowed depth. */
1848        if (src->depth >= max_depth)
1849                return 0;
1850
1851        /* Now some size filtering heuristics. */
1852        trg_size = trg_entry->size;
1853        if (!trg_entry->delta) {
1854                max_size = trg_size/2 - 20;
1855                ref_depth = 1;
1856        } else {
1857                max_size = trg_entry->delta_size;
1858                ref_depth = trg->depth;
1859        }
1860        max_size = (uint64_t)max_size * (max_depth - src->depth) /
1861                                                (max_depth - ref_depth + 1);
1862        if (max_size == 0)
1863                return 0;
1864        src_size = src_entry->size;
1865        sizediff = src_size < trg_size ? trg_size - src_size : 0;
1866        if (sizediff >= max_size)
1867                return 0;
1868        if (trg_size < src_size / 32)
1869                return 0;
1870
1871        /* Load data if not already done */
1872        if (!trg->data) {
1873                read_lock();
1874                trg->data = read_sha1_file(trg_entry->idx.oid.hash, &type,
1875                                           &sz);
1876                read_unlock();
1877                if (!trg->data)
1878                        die("object %s cannot be read",
1879                            oid_to_hex(&trg_entry->idx.oid));
1880                if (sz != trg_size)
1881                        die("object %s inconsistent object length (%lu vs %lu)",
1882                            oid_to_hex(&trg_entry->idx.oid), sz,
1883                            trg_size);
1884                *mem_usage += sz;
1885        }
1886        if (!src->data) {
1887                read_lock();
1888                src->data = read_sha1_file(src_entry->idx.oid.hash, &type,
1889                                           &sz);
1890                read_unlock();
1891                if (!src->data) {
1892                        if (src_entry->preferred_base) {
1893                                static int warned = 0;
1894                                if (!warned++)
1895                                        warning("object %s cannot be read",
1896                                                oid_to_hex(&src_entry->idx.oid));
1897                                /*
1898                                 * Those objects are not included in the
1899                                 * resulting pack.  Be resilient and ignore
1900                                 * them if they can't be read, in case the
1901                                 * pack could be created nevertheless.
1902                                 */
1903                                return 0;
1904                        }
1905                        die("object %s cannot be read",
1906                            oid_to_hex(&src_entry->idx.oid));
1907                }
1908                if (sz != src_size)
1909                        die("object %s inconsistent object length (%lu vs %lu)",
1910                            oid_to_hex(&src_entry->idx.oid), sz,
1911                            src_size);
1912                *mem_usage += sz;
1913        }
1914        if (!src->index) {
1915                src->index = create_delta_index(src->data, src_size);
1916                if (!src->index) {
1917                        static int warned = 0;
1918                        if (!warned++)
1919                                warning("suboptimal pack - out of memory");
1920                        return 0;
1921                }
1922                *mem_usage += sizeof_delta_index(src->index);
1923        }
1924
1925        delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1926        if (!delta_buf)
1927                return 0;
1928
1929        if (trg_entry->delta) {
1930                /* Prefer only shallower same-sized deltas. */
1931                if (delta_size == trg_entry->delta_size &&
1932                    src->depth + 1 >= trg->depth) {
1933                        free(delta_buf);
1934                        return 0;
1935                }
1936        }
1937
1938        /*
1939         * Handle memory allocation outside of the cache
1940         * accounting lock.  Compiler will optimize the strangeness
1941         * away when NO_PTHREADS is defined.
1942         */
1943        free(trg_entry->delta_data);
1944        cache_lock();
1945        if (trg_entry->delta_data) {
1946                delta_cache_size -= trg_entry->delta_size;
1947                trg_entry->delta_data = NULL;
1948        }
1949        if (delta_cacheable(src_size, trg_size, delta_size)) {
1950                delta_cache_size += delta_size;
1951                cache_unlock();
1952                trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1953        } else {
1954                cache_unlock();
1955                free(delta_buf);
1956        }
1957
1958        trg_entry->delta = src_entry;
1959        trg_entry->delta_size = delta_size;
1960        trg->depth = src->depth + 1;
1961
1962        return 1;
1963}
1964
1965static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1966{
1967        struct object_entry *child = me->delta_child;
1968        unsigned int m = n;
1969        while (child) {
1970                unsigned int c = check_delta_limit(child, n + 1);
1971                if (m < c)
1972                        m = c;
1973                child = child->delta_sibling;
1974        }
1975        return m;
1976}
1977
1978static unsigned long free_unpacked(struct unpacked *n)
1979{
1980        unsigned long freed_mem = sizeof_delta_index(n->index);
1981        free_delta_index(n->index);
1982        n->index = NULL;
1983        if (n->data) {
1984                freed_mem += n->entry->size;
1985                FREE_AND_NULL(n->data);
1986        }
1987        n->entry = NULL;
1988        n->depth = 0;
1989        return freed_mem;
1990}
1991
1992static void find_deltas(struct object_entry **list, unsigned *list_size,
1993                        int window, int depth, unsigned *processed)
1994{
1995        uint32_t i, idx = 0, count = 0;
1996        struct unpacked *array;
1997        unsigned long mem_usage = 0;
1998
1999        array = xcalloc(window, sizeof(struct unpacked));
2000
2001        for (;;) {
2002                struct object_entry *entry;
2003                struct unpacked *n = array + idx;
2004                int j, max_depth, best_base = -1;
2005
2006                progress_lock();
2007                if (!*list_size) {
2008                        progress_unlock();
2009                        break;
2010                }
2011                entry = *list++;
2012                (*list_size)--;
2013                if (!entry->preferred_base) {
2014                        (*processed)++;
2015                        display_progress(progress_state, *processed);
2016                }
2017                progress_unlock();
2018
2019                mem_usage -= free_unpacked(n);
2020                n->entry = entry;
2021
2022                while (window_memory_limit &&
2023                       mem_usage > window_memory_limit &&
2024                       count > 1) {
2025                        uint32_t tail = (idx + window - count) % window;
2026                        mem_usage -= free_unpacked(array + tail);
2027                        count--;
2028                }
2029
2030                /* We do not compute delta to *create* objects we are not
2031                 * going to pack.
2032                 */
2033                if (entry->preferred_base)
2034                        goto next;
2035
2036                /*
2037                 * If the current object is at pack edge, take the depth the
2038                 * objects that depend on the current object into account
2039                 * otherwise they would become too deep.
2040                 */
2041                max_depth = depth;
2042                if (entry->delta_child) {
2043                        max_depth -= check_delta_limit(entry, 0);
2044                        if (max_depth <= 0)
2045                                goto next;
2046                }
2047
2048                j = window;
2049                while (--j > 0) {
2050                        int ret;
2051                        uint32_t other_idx = idx + j;
2052                        struct unpacked *m;
2053                        if (other_idx >= window)
2054                                other_idx -= window;
2055                        m = array + other_idx;
2056                        if (!m->entry)
2057                                break;
2058                        ret = try_delta(n, m, max_depth, &mem_usage);
2059                        if (ret < 0)
2060                                break;
2061                        else if (ret > 0)
2062                                best_base = other_idx;
2063                }
2064
2065                /*
2066                 * If we decided to cache the delta data, then it is best
2067                 * to compress it right away.  First because we have to do
2068                 * it anyway, and doing it here while we're threaded will
2069                 * save a lot of time in the non threaded write phase,
2070                 * as well as allow for caching more deltas within
2071                 * the same cache size limit.
2072                 * ...
2073                 * But only if not writing to stdout, since in that case
2074                 * the network is most likely throttling writes anyway,
2075                 * and therefore it is best to go to the write phase ASAP
2076                 * instead, as we can afford spending more time compressing
2077                 * between writes at that moment.
2078                 */
2079                if (entry->delta_data && !pack_to_stdout) {
2080                        entry->z_delta_size = do_compress(&entry->delta_data,
2081                                                          entry->delta_size);
2082                        cache_lock();
2083                        delta_cache_size -= entry->delta_size;
2084                        delta_cache_size += entry->z_delta_size;
2085                        cache_unlock();
2086                }
2087
2088                /* if we made n a delta, and if n is already at max
2089                 * depth, leaving it in the window is pointless.  we
2090                 * should evict it first.
2091                 */
2092                if (entry->delta && max_depth <= n->depth)
2093                        continue;
2094
2095                /*
2096                 * Move the best delta base up in the window, after the
2097                 * currently deltified object, to keep it longer.  It will
2098                 * be the first base object to be attempted next.
2099                 */
2100                if (entry->delta) {
2101                        struct unpacked swap = array[best_base];
2102                        int dist = (window + idx - best_base) % window;
2103                        int dst = best_base;
2104                        while (dist--) {
2105                                int src = (dst + 1) % window;
2106                                array[dst] = array[src];
2107                                dst = src;
2108                        }
2109                        array[dst] = swap;
2110                }
2111
2112                next:
2113                idx++;
2114                if (count + 1 < window)
2115                        count++;
2116                if (idx >= window)
2117                        idx = 0;
2118        }
2119
2120        for (i = 0; i < window; ++i) {
2121                free_delta_index(array[i].index);
2122                free(array[i].data);
2123        }
2124        free(array);
2125}
2126
2127#ifndef NO_PTHREADS
2128
2129static void try_to_free_from_threads(size_t size)
2130{
2131        read_lock();
2132        release_pack_memory(size);
2133        read_unlock();
2134}
2135
2136static try_to_free_t old_try_to_free_routine;
2137
2138/*
2139 * The main thread waits on the condition that (at least) one of the workers
2140 * has stopped working (which is indicated in the .working member of
2141 * struct thread_params).
2142 * When a work thread has completed its work, it sets .working to 0 and
2143 * signals the main thread and waits on the condition that .data_ready
2144 * becomes 1.
2145 */
2146
2147struct thread_params {
2148        pthread_t thread;
2149        struct object_entry **list;
2150        unsigned list_size;
2151        unsigned remaining;
2152        int window;
2153        int depth;
2154        int working;
2155        int data_ready;
2156        pthread_mutex_t mutex;
2157        pthread_cond_t cond;
2158        unsigned *processed;
2159};
2160
2161static pthread_cond_t progress_cond;
2162
2163/*
2164 * Mutex and conditional variable can't be statically-initialized on Windows.
2165 */
2166static void init_threaded_search(void)
2167{
2168        init_recursive_mutex(&read_mutex);
2169        pthread_mutex_init(&cache_mutex, NULL);
2170        pthread_mutex_init(&progress_mutex, NULL);
2171        pthread_cond_init(&progress_cond, NULL);
2172        old_try_to_free_routine = set_try_to_free_routine(try_to_free_from_threads);
2173}
2174
2175static void cleanup_threaded_search(void)
2176{
2177        set_try_to_free_routine(old_try_to_free_routine);
2178        pthread_cond_destroy(&progress_cond);
2179        pthread_mutex_destroy(&read_mutex);
2180        pthread_mutex_destroy(&cache_mutex);
2181        pthread_mutex_destroy(&progress_mutex);
2182}
2183
2184static void *threaded_find_deltas(void *arg)
2185{
2186        struct thread_params *me = arg;
2187
2188        progress_lock();
2189        while (me->remaining) {
2190                progress_unlock();
2191
2192                find_deltas(me->list, &me->remaining,
2193                            me->window, me->depth, me->processed);
2194
2195                progress_lock();
2196                me->working = 0;
2197                pthread_cond_signal(&progress_cond);
2198                progress_unlock();
2199
2200                /*
2201                 * We must not set ->data_ready before we wait on the
2202                 * condition because the main thread may have set it to 1
2203                 * before we get here. In order to be sure that new
2204                 * work is available if we see 1 in ->data_ready, it
2205                 * was initialized to 0 before this thread was spawned
2206                 * and we reset it to 0 right away.
2207                 */
2208                pthread_mutex_lock(&me->mutex);
2209                while (!me->data_ready)
2210                        pthread_cond_wait(&me->cond, &me->mutex);
2211                me->data_ready = 0;
2212                pthread_mutex_unlock(&me->mutex);
2213
2214                progress_lock();
2215        }
2216        progress_unlock();
2217        /* leave ->working 1 so that this doesn't get more work assigned */
2218        return NULL;
2219}
2220
2221static void ll_find_deltas(struct object_entry **list, unsigned list_size,
2222                           int window, int depth, unsigned *processed)
2223{
2224        struct thread_params *p;
2225        int i, ret, active_threads = 0;
2226
2227        init_threaded_search();
2228
2229        if (delta_search_threads <= 1) {
2230                find_deltas(list, &list_size, window, depth, processed);
2231                cleanup_threaded_search();
2232                return;
2233        }
2234        if (progress > pack_to_stdout)
2235                fprintf(stderr, "Delta compression using up to %d threads.\n",
2236                                delta_search_threads);
2237        p = xcalloc(delta_search_threads, sizeof(*p));
2238
2239        /* Partition the work amongst work threads. */
2240        for (i = 0; i < delta_search_threads; i++) {
2241                unsigned sub_size = list_size / (delta_search_threads - i);
2242
2243                /* don't use too small segments or no deltas will be found */
2244                if (sub_size < 2*window && i+1 < delta_search_threads)
2245                        sub_size = 0;
2246
2247                p[i].window = window;
2248                p[i].depth = depth;
2249                p[i].processed = processed;
2250                p[i].working = 1;
2251                p[i].data_ready = 0;
2252
2253                /* try to split chunks on "path" boundaries */
2254                while (sub_size && sub_size < list_size &&
2255                       list[sub_size]->hash &&
2256                       list[sub_size]->hash == list[sub_size-1]->hash)
2257                        sub_size++;
2258
2259                p[i].list = list;
2260                p[i].list_size = sub_size;
2261                p[i].remaining = sub_size;
2262
2263                list += sub_size;
2264                list_size -= sub_size;
2265        }
2266
2267        /* Start work threads. */
2268        for (i = 0; i < delta_search_threads; i++) {
2269                if (!p[i].list_size)
2270                        continue;
2271                pthread_mutex_init(&p[i].mutex, NULL);
2272                pthread_cond_init(&p[i].cond, NULL);
2273                ret = pthread_create(&p[i].thread, NULL,
2274                                     threaded_find_deltas, &p[i]);
2275                if (ret)
2276                        die("unable to create thread: %s", strerror(ret));
2277                active_threads++;
2278        }
2279
2280        /*
2281         * Now let's wait for work completion.  Each time a thread is done
2282         * with its work, we steal half of the remaining work from the
2283         * thread with the largest number of unprocessed objects and give
2284         * it to that newly idle thread.  This ensure good load balancing
2285         * until the remaining object list segments are simply too short
2286         * to be worth splitting anymore.
2287         */
2288        while (active_threads) {
2289                struct thread_params *target = NULL;
2290                struct thread_params *victim = NULL;
2291                unsigned sub_size = 0;
2292
2293                progress_lock();
2294                for (;;) {
2295                        for (i = 0; !target && i < delta_search_threads; i++)
2296                                if (!p[i].working)
2297                                        target = &p[i];
2298                        if (target)
2299                                break;
2300                        pthread_cond_wait(&progress_cond, &progress_mutex);
2301                }
2302
2303                for (i = 0; i < delta_search_threads; i++)
2304                        if (p[i].remaining > 2*window &&
2305                            (!victim || victim->remaining < p[i].remaining))
2306                                victim = &p[i];
2307                if (victim) {
2308                        sub_size = victim->remaining / 2;
2309                        list = victim->list + victim->list_size - sub_size;
2310                        while (sub_size && list[0]->hash &&
2311                               list[0]->hash == list[-1]->hash) {
2312                                list++;
2313                                sub_size--;
2314                        }
2315                        if (!sub_size) {
2316                                /*
2317                                 * It is possible for some "paths" to have
2318                                 * so many objects that no hash boundary
2319                                 * might be found.  Let's just steal the
2320                                 * exact half in that case.
2321                                 */
2322                                sub_size = victim->remaining / 2;
2323                                list -= sub_size;
2324                        }
2325                        target->list = list;
2326                        victim->list_size -= sub_size;
2327                        victim->remaining -= sub_size;
2328                }
2329                target->list_size = sub_size;
2330                target->remaining = sub_size;
2331                target->working = 1;
2332                progress_unlock();
2333
2334                pthread_mutex_lock(&target->mutex);
2335                target->data_ready = 1;
2336                pthread_cond_signal(&target->cond);
2337                pthread_mutex_unlock(&target->mutex);
2338
2339                if (!sub_size) {
2340                        pthread_join(target->thread, NULL);
2341                        pthread_cond_destroy(&target->cond);
2342                        pthread_mutex_destroy(&target->mutex);
2343                        active_threads--;
2344                }
2345        }
2346        cleanup_threaded_search();
2347        free(p);
2348}
2349
2350#else
2351#define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
2352#endif
2353
2354static void add_tag_chain(const struct object_id *oid)
2355{
2356        struct tag *tag;
2357
2358        /*
2359         * We catch duplicates already in add_object_entry(), but we'd
2360         * prefer to do this extra check to avoid having to parse the
2361         * tag at all if we already know that it's being packed (e.g., if
2362         * it was included via bitmaps, we would not have parsed it
2363         * previously).
2364         */
2365        if (packlist_find(&to_pack, oid->hash, NULL))
2366                return;
2367
2368        tag = lookup_tag(oid);
2369        while (1) {
2370                if (!tag || parse_tag(tag) || !tag->tagged)
2371                        die("unable to pack objects reachable from tag %s",
2372                            oid_to_hex(oid));
2373
2374                add_object_entry(&tag->object.oid, OBJ_TAG, NULL, 0);
2375
2376                if (tag->tagged->type != OBJ_TAG)
2377                        return;
2378
2379                tag = (struct tag *)tag->tagged;
2380        }
2381}
2382
2383static int add_ref_tag(const char *path, const struct object_id *oid, int flag, void *cb_data)
2384{
2385        struct object_id peeled;
2386
2387        if (starts_with(path, "refs/tags/") && /* is a tag? */
2388            !peel_ref(path, &peeled)    && /* peelable? */
2389            packlist_find(&to_pack, peeled.hash, NULL))      /* object packed? */
2390                add_tag_chain(oid);
2391        return 0;
2392}
2393
2394static void prepare_pack(int window, int depth)
2395{
2396        struct object_entry **delta_list;
2397        uint32_t i, nr_deltas;
2398        unsigned n;
2399
2400        get_object_details();
2401
2402        /*
2403         * If we're locally repacking then we need to be doubly careful
2404         * from now on in order to make sure no stealth corruption gets
2405         * propagated to the new pack.  Clients receiving streamed packs
2406         * should validate everything they get anyway so no need to incur
2407         * the additional cost here in that case.
2408         */
2409        if (!pack_to_stdout)
2410                do_check_packed_object_crc = 1;
2411
2412        if (!to_pack.nr_objects || !window || !depth)
2413                return;
2414
2415        ALLOC_ARRAY(delta_list, to_pack.nr_objects);
2416        nr_deltas = n = 0;
2417
2418        for (i = 0; i < to_pack.nr_objects; i++) {
2419                struct object_entry *entry = to_pack.objects + i;
2420
2421                if (entry->delta)
2422                        /* This happens if we decided to reuse existing
2423                         * delta from a pack.  "reuse_delta &&" is implied.
2424                         */
2425                        continue;
2426
2427                if (entry->size < 50)
2428                        continue;
2429
2430                if (entry->no_try_delta)
2431                        continue;
2432
2433                if (!entry->preferred_base) {
2434                        nr_deltas++;
2435                        if (entry->type < 0)
2436                                die("unable to get type of object %s",
2437                                    oid_to_hex(&entry->idx.oid));
2438                } else {
2439                        if (entry->type < 0) {
2440                                /*
2441                                 * This object is not found, but we
2442                                 * don't have to include it anyway.
2443                                 */
2444                                continue;
2445                        }
2446                }
2447
2448                delta_list[n++] = entry;
2449        }
2450
2451        if (nr_deltas && n > 1) {
2452                unsigned nr_done = 0;
2453                if (progress)
2454                        progress_state = start_progress(_("Compressing objects"),
2455                                                        nr_deltas);
2456                QSORT(delta_list, n, type_size_sort);
2457                ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
2458                stop_progress(&progress_state);
2459                if (nr_done != nr_deltas)
2460                        die("inconsistency with delta count");
2461        }
2462        free(delta_list);
2463}
2464
2465static int git_pack_config(const char *k, const char *v, void *cb)
2466{
2467        if (!strcmp(k, "pack.window")) {
2468                window = git_config_int(k, v);
2469                return 0;
2470        }
2471        if (!strcmp(k, "pack.windowmemory")) {
2472                window_memory_limit = git_config_ulong(k, v);
2473                return 0;
2474        }
2475        if (!strcmp(k, "pack.depth")) {
2476                depth = git_config_int(k, v);
2477                return 0;
2478        }
2479        if (!strcmp(k, "pack.deltacachesize")) {
2480                max_delta_cache_size = git_config_int(k, v);
2481                return 0;
2482        }
2483        if (!strcmp(k, "pack.deltacachelimit")) {
2484                cache_max_small_delta_size = git_config_int(k, v);
2485                return 0;
2486        }
2487        if (!strcmp(k, "pack.writebitmaphashcache")) {
2488                if (git_config_bool(k, v))
2489                        write_bitmap_options |= BITMAP_OPT_HASH_CACHE;
2490                else
2491                        write_bitmap_options &= ~BITMAP_OPT_HASH_CACHE;
2492        }
2493        if (!strcmp(k, "pack.usebitmaps")) {
2494                use_bitmap_index_default = git_config_bool(k, v);
2495                return 0;
2496        }
2497        if (!strcmp(k, "pack.threads")) {
2498                delta_search_threads = git_config_int(k, v);
2499                if (delta_search_threads < 0)
2500                        die("invalid number of threads specified (%d)",
2501                            delta_search_threads);
2502#ifdef NO_PTHREADS
2503                if (delta_search_threads != 1) {
2504                        warning("no threads support, ignoring %s", k);
2505                        delta_search_threads = 0;
2506                }
2507#endif
2508                return 0;
2509        }
2510        if (!strcmp(k, "pack.indexversion")) {
2511                pack_idx_opts.version = git_config_int(k, v);
2512                if (pack_idx_opts.version > 2)
2513                        die("bad pack.indexversion=%"PRIu32,
2514                            pack_idx_opts.version);
2515                return 0;
2516        }
2517        return git_default_config(k, v, cb);
2518}
2519
2520static void read_object_list_from_stdin(void)
2521{
2522        char line[GIT_MAX_HEXSZ + 1 + PATH_MAX + 2];
2523        struct object_id oid;
2524        const char *p;
2525
2526        for (;;) {
2527                if (!fgets(line, sizeof(line), stdin)) {
2528                        if (feof(stdin))
2529                                break;
2530                        if (!ferror(stdin))
2531                                die("fgets returned NULL, not EOF, not error!");
2532                        if (errno != EINTR)
2533                                die_errno("fgets");
2534                        clearerr(stdin);
2535                        continue;
2536                }
2537                if (line[0] == '-') {
2538                        if (get_oid_hex(line+1, &oid))
2539                                die("expected edge object ID, got garbage:\n %s",
2540                                    line);
2541                        add_preferred_base(&oid);
2542                        continue;
2543                }
2544                if (parse_oid_hex(line, &oid, &p))
2545                        die("expected object ID, got garbage:\n %s", line);
2546
2547                add_preferred_base_object(p + 1);
2548                add_object_entry(&oid, 0, p + 1, 0);
2549        }
2550}
2551
2552#define OBJECT_ADDED (1u<<20)
2553
2554static void show_commit(struct commit *commit, void *data)
2555{
2556        add_object_entry(&commit->object.oid, OBJ_COMMIT, NULL, 0);
2557        commit->object.flags |= OBJECT_ADDED;
2558
2559        if (write_bitmap_index)
2560                index_commit_for_bitmap(commit);
2561}
2562
2563static void show_object(struct object *obj, const char *name, void *data)
2564{
2565        add_preferred_base_object(name);
2566        add_object_entry(&obj->oid, obj->type, name, 0);
2567        obj->flags |= OBJECT_ADDED;
2568}
2569
2570static void show_object__ma_allow_any(struct object *obj, const char *name, void *data)
2571{
2572        assert(arg_missing_action == MA_ALLOW_ANY);
2573
2574        /*
2575         * Quietly ignore ALL missing objects.  This avoids problems with
2576         * staging them now and getting an odd error later.
2577         */
2578        if (!has_object_file(&obj->oid))
2579                return;
2580
2581        show_object(obj, name, data);
2582}
2583
2584static void show_object__ma_allow_promisor(struct object *obj, const char *name, void *data)
2585{
2586        assert(arg_missing_action == MA_ALLOW_PROMISOR);
2587
2588        /*
2589         * Quietly ignore EXPECTED missing objects.  This avoids problems with
2590         * staging them now and getting an odd error later.
2591         */
2592        if (!has_object_file(&obj->oid) && is_promisor_object(&obj->oid))
2593                return;
2594
2595        show_object(obj, name, data);
2596}
2597
2598static int option_parse_missing_action(const struct option *opt,
2599                                       const char *arg, int unset)
2600{
2601        assert(arg);
2602        assert(!unset);
2603
2604        if (!strcmp(arg, "error")) {
2605                arg_missing_action = MA_ERROR;
2606                fn_show_object = show_object;
2607                return 0;
2608        }
2609
2610        if (!strcmp(arg, "allow-any")) {
2611                arg_missing_action = MA_ALLOW_ANY;
2612                fetch_if_missing = 0;
2613                fn_show_object = show_object__ma_allow_any;
2614                return 0;
2615        }
2616
2617        if (!strcmp(arg, "allow-promisor")) {
2618                arg_missing_action = MA_ALLOW_PROMISOR;
2619                fetch_if_missing = 0;
2620                fn_show_object = show_object__ma_allow_promisor;
2621                return 0;
2622        }
2623
2624        die(_("invalid value for --missing"));
2625        return 0;
2626}
2627
2628static void show_edge(struct commit *commit)
2629{
2630        add_preferred_base(&commit->object.oid);
2631}
2632
2633struct in_pack_object {
2634        off_t offset;
2635        struct object *object;
2636};
2637
2638struct in_pack {
2639        unsigned int alloc;
2640        unsigned int nr;
2641        struct in_pack_object *array;
2642};
2643
2644static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
2645{
2646        in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->oid.hash, p);
2647        in_pack->array[in_pack->nr].object = object;
2648        in_pack->nr++;
2649}
2650
2651/*
2652 * Compare the objects in the offset order, in order to emulate the
2653 * "git rev-list --objects" output that produced the pack originally.
2654 */
2655static int ofscmp(const void *a_, const void *b_)
2656{
2657        struct in_pack_object *a = (struct in_pack_object *)a_;
2658        struct in_pack_object *b = (struct in_pack_object *)b_;
2659
2660        if (a->offset < b->offset)
2661                return -1;
2662        else if (a->offset > b->offset)
2663                return 1;
2664        else
2665                return oidcmp(&a->object->oid, &b->object->oid);
2666}
2667
2668static void add_objects_in_unpacked_packs(struct rev_info *revs)
2669{
2670        struct packed_git *p;
2671        struct in_pack in_pack;
2672        uint32_t i;
2673
2674        memset(&in_pack, 0, sizeof(in_pack));
2675
2676        for (p = packed_git; p; p = p->next) {
2677                struct object_id oid;
2678                struct object *o;
2679
2680                if (!p->pack_local || p->pack_keep)
2681                        continue;
2682                if (open_pack_index(p))
2683                        die("cannot open pack index");
2684
2685                ALLOC_GROW(in_pack.array,
2686                           in_pack.nr + p->num_objects,
2687                           in_pack.alloc);
2688
2689                for (i = 0; i < p->num_objects; i++) {
2690                        nth_packed_object_oid(&oid, p, i);
2691                        o = lookup_unknown_object(oid.hash);
2692                        if (!(o->flags & OBJECT_ADDED))
2693                                mark_in_pack_object(o, p, &in_pack);
2694                        o->flags |= OBJECT_ADDED;
2695                }
2696        }
2697
2698        if (in_pack.nr) {
2699                QSORT(in_pack.array, in_pack.nr, ofscmp);
2700                for (i = 0; i < in_pack.nr; i++) {
2701                        struct object *o = in_pack.array[i].object;
2702                        add_object_entry(&o->oid, o->type, "", 0);
2703                }
2704        }
2705        free(in_pack.array);
2706}
2707
2708static int add_loose_object(const struct object_id *oid, const char *path,
2709                            void *data)
2710{
2711        enum object_type type = sha1_object_info(oid->hash, NULL);
2712
2713        if (type < 0) {
2714                warning("loose object at %s could not be examined", path);
2715                return 0;
2716        }
2717
2718        add_object_entry(oid, type, "", 0);
2719        return 0;
2720}
2721
2722/*
2723 * We actually don't even have to worry about reachability here.
2724 * add_object_entry will weed out duplicates, so we just add every
2725 * loose object we find.
2726 */
2727static void add_unreachable_loose_objects(void)
2728{
2729        for_each_loose_file_in_objdir(get_object_directory(),
2730                                      add_loose_object,
2731                                      NULL, NULL, NULL);
2732}
2733
2734static int has_sha1_pack_kept_or_nonlocal(const struct object_id *oid)
2735{
2736        static struct packed_git *last_found = (void *)1;
2737        struct packed_git *p;
2738
2739        p = (last_found != (void *)1) ? last_found : packed_git;
2740
2741        while (p) {
2742                if ((!p->pack_local || p->pack_keep) &&
2743                        find_pack_entry_one(oid->hash, p)) {
2744                        last_found = p;
2745                        return 1;
2746                }
2747                if (p == last_found)
2748                        p = packed_git;
2749                else
2750                        p = p->next;
2751                if (p == last_found)
2752                        p = p->next;
2753        }
2754        return 0;
2755}
2756
2757/*
2758 * Store a list of sha1s that are should not be discarded
2759 * because they are either written too recently, or are
2760 * reachable from another object that was.
2761 *
2762 * This is filled by get_object_list.
2763 */
2764static struct oid_array recent_objects;
2765
2766static int loosened_object_can_be_discarded(const struct object_id *oid,
2767                                            timestamp_t mtime)
2768{
2769        if (!unpack_unreachable_expiration)
2770                return 0;
2771        if (mtime > unpack_unreachable_expiration)
2772                return 0;
2773        if (oid_array_lookup(&recent_objects, oid) >= 0)
2774                return 0;
2775        return 1;
2776}
2777
2778static void loosen_unused_packed_objects(struct rev_info *revs)
2779{
2780        struct packed_git *p;
2781        uint32_t i;
2782        struct object_id oid;
2783
2784        for (p = packed_git; p; p = p->next) {
2785                if (!p->pack_local || p->pack_keep)
2786                        continue;
2787
2788                if (open_pack_index(p))
2789                        die("cannot open pack index");
2790
2791                for (i = 0; i < p->num_objects; i++) {
2792                        nth_packed_object_oid(&oid, p, i);
2793                        if (!packlist_find(&to_pack, oid.hash, NULL) &&
2794                            !has_sha1_pack_kept_or_nonlocal(&oid) &&
2795                            !loosened_object_can_be_discarded(&oid, p->mtime))
2796                                if (force_object_loose(oid.hash, p->mtime))
2797                                        die("unable to force loose object");
2798                }
2799        }
2800}
2801
2802/*
2803 * This tracks any options which pack-reuse code expects to be on, or which a
2804 * reader of the pack might not understand, and which would therefore prevent
2805 * blind reuse of what we have on disk.
2806 */
2807static int pack_options_allow_reuse(void)
2808{
2809        return pack_to_stdout &&
2810               allow_ofs_delta &&
2811               !ignore_packed_keep &&
2812               (!local || !have_non_local_packs) &&
2813               !incremental;
2814}
2815
2816static int get_object_list_from_bitmap(struct rev_info *revs)
2817{
2818        if (prepare_bitmap_walk(revs) < 0)
2819                return -1;
2820
2821        if (pack_options_allow_reuse() &&
2822            !reuse_partial_packfile_from_bitmap(
2823                        &reuse_packfile,
2824                        &reuse_packfile_objects,
2825                        &reuse_packfile_offset)) {
2826                assert(reuse_packfile_objects);
2827                nr_result += reuse_packfile_objects;
2828                display_progress(progress_state, nr_result);
2829        }
2830
2831        traverse_bitmap_commit_list(&add_object_entry_from_bitmap);
2832        return 0;
2833}
2834
2835static void record_recent_object(struct object *obj,
2836                                 const char *name,
2837                                 void *data)
2838{
2839        oid_array_append(&recent_objects, &obj->oid);
2840}
2841
2842static void record_recent_commit(struct commit *commit, void *data)
2843{
2844        oid_array_append(&recent_objects, &commit->object.oid);
2845}
2846
2847static void get_object_list(int ac, const char **av)
2848{
2849        struct rev_info revs;
2850        char line[1000];
2851        int flags = 0;
2852
2853        init_revisions(&revs, NULL);
2854        save_commit_buffer = 0;
2855        setup_revisions(ac, av, &revs, NULL);
2856
2857        /* make sure shallows are read */
2858        is_repository_shallow();
2859
2860        while (fgets(line, sizeof(line), stdin) != NULL) {
2861                int len = strlen(line);
2862                if (len && line[len - 1] == '\n')
2863                        line[--len] = 0;
2864                if (!len)
2865                        break;
2866                if (*line == '-') {
2867                        if (!strcmp(line, "--not")) {
2868                                flags ^= UNINTERESTING;
2869                                write_bitmap_index = 0;
2870                                continue;
2871                        }
2872                        if (starts_with(line, "--shallow ")) {
2873                                struct object_id oid;
2874                                if (get_oid_hex(line + 10, &oid))
2875                                        die("not an SHA-1 '%s'", line + 10);
2876                                register_shallow(&oid);
2877                                use_bitmap_index = 0;
2878                                continue;
2879                        }
2880                        die("not a rev '%s'", line);
2881                }
2882                if (handle_revision_arg(line, &revs, flags, REVARG_CANNOT_BE_FILENAME))
2883                        die("bad revision '%s'", line);
2884        }
2885
2886        if (use_bitmap_index && !get_object_list_from_bitmap(&revs))
2887                return;
2888
2889        if (prepare_revision_walk(&revs))
2890                die("revision walk setup failed");
2891        mark_edges_uninteresting(&revs, show_edge);
2892
2893        if (!fn_show_object)
2894                fn_show_object = show_object;
2895        traverse_commit_list_filtered(&filter_options, &revs,
2896                                      show_commit, fn_show_object, NULL,
2897                                      NULL);
2898
2899        if (unpack_unreachable_expiration) {
2900                revs.ignore_missing_links = 1;
2901                if (add_unseen_recent_objects_to_traversal(&revs,
2902                                unpack_unreachable_expiration))
2903                        die("unable to add recent objects");
2904                if (prepare_revision_walk(&revs))
2905                        die("revision walk setup failed");
2906                traverse_commit_list(&revs, record_recent_commit,
2907                                     record_recent_object, NULL);
2908        }
2909
2910        if (keep_unreachable)
2911                add_objects_in_unpacked_packs(&revs);
2912        if (pack_loose_unreachable)
2913                add_unreachable_loose_objects();
2914        if (unpack_unreachable)
2915                loosen_unused_packed_objects(&revs);
2916
2917        oid_array_clear(&recent_objects);
2918}
2919
2920static int option_parse_index_version(const struct option *opt,
2921                                      const char *arg, int unset)
2922{
2923        char *c;
2924        const char *val = arg;
2925        pack_idx_opts.version = strtoul(val, &c, 10);
2926        if (pack_idx_opts.version > 2)
2927                die(_("unsupported index version %s"), val);
2928        if (*c == ',' && c[1])
2929                pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
2930        if (*c || pack_idx_opts.off32_limit & 0x80000000)
2931                die(_("bad index version '%s'"), val);
2932        return 0;
2933}
2934
2935static int option_parse_unpack_unreachable(const struct option *opt,
2936                                           const char *arg, int unset)
2937{
2938        if (unset) {
2939                unpack_unreachable = 0;
2940                unpack_unreachable_expiration = 0;
2941        }
2942        else {
2943                unpack_unreachable = 1;
2944                if (arg)
2945                        unpack_unreachable_expiration = approxidate(arg);
2946        }
2947        return 0;
2948}
2949
2950int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2951{
2952        int use_internal_rev_list = 0;
2953        int thin = 0;
2954        int shallow = 0;
2955        int all_progress_implied = 0;
2956        struct argv_array rp = ARGV_ARRAY_INIT;
2957        int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
2958        int rev_list_index = 0;
2959        struct option pack_objects_options[] = {
2960                OPT_SET_INT('q', "quiet", &progress,
2961                            N_("do not show progress meter"), 0),
2962                OPT_SET_INT(0, "progress", &progress,
2963                            N_("show progress meter"), 1),
2964                OPT_SET_INT(0, "all-progress", &progress,
2965                            N_("show progress meter during object writing phase"), 2),
2966                OPT_BOOL(0, "all-progress-implied",
2967                         &all_progress_implied,
2968                         N_("similar to --all-progress when progress meter is shown")),
2969                { OPTION_CALLBACK, 0, "index-version", NULL, N_("version[,offset]"),
2970                  N_("write the pack index file in the specified idx format version"),
2971                  0, option_parse_index_version },
2972                OPT_MAGNITUDE(0, "max-pack-size", &pack_size_limit,
2973                              N_("maximum size of each output pack file")),
2974                OPT_BOOL(0, "local", &local,
2975                         N_("ignore borrowed objects from alternate object store")),
2976                OPT_BOOL(0, "incremental", &incremental,
2977                         N_("ignore packed objects")),
2978                OPT_INTEGER(0, "window", &window,
2979                            N_("limit pack window by objects")),
2980                OPT_MAGNITUDE(0, "window-memory", &window_memory_limit,
2981                              N_("limit pack window by memory in addition to object limit")),
2982                OPT_INTEGER(0, "depth", &depth,
2983                            N_("maximum length of delta chain allowed in the resulting pack")),
2984                OPT_BOOL(0, "reuse-delta", &reuse_delta,
2985                         N_("reuse existing deltas")),
2986                OPT_BOOL(0, "reuse-object", &reuse_object,
2987                         N_("reuse existing objects")),
2988                OPT_BOOL(0, "delta-base-offset", &allow_ofs_delta,
2989                         N_("use OFS_DELTA objects")),
2990                OPT_INTEGER(0, "threads", &delta_search_threads,
2991                            N_("use threads when searching for best delta matches")),
2992                OPT_BOOL(0, "non-empty", &non_empty,
2993                         N_("do not create an empty pack output")),
2994                OPT_BOOL(0, "revs", &use_internal_rev_list,
2995                         N_("read revision arguments from standard input")),
2996                { OPTION_SET_INT, 0, "unpacked", &rev_list_unpacked, NULL,
2997                  N_("limit the objects to those that are not yet packed"),
2998                  PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2999                { OPTION_SET_INT, 0, "all", &rev_list_all, NULL,
3000                  N_("include objects reachable from any reference"),
3001                  PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
3002                { OPTION_SET_INT, 0, "reflog", &rev_list_reflog, NULL,
3003                  N_("include objects referred by reflog entries"),
3004                  PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
3005                { OPTION_SET_INT, 0, "indexed-objects", &rev_list_index, NULL,
3006                  N_("include objects referred to by the index"),
3007                  PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
3008                OPT_BOOL(0, "stdout", &pack_to_stdout,
3009                         N_("output pack to stdout")),
3010                OPT_BOOL(0, "include-tag", &include_tag,
3011                         N_("include tag objects that refer to objects to be packed")),
3012                OPT_BOOL(0, "keep-unreachable", &keep_unreachable,
3013                         N_("keep unreachable objects")),
3014                OPT_BOOL(0, "pack-loose-unreachable", &pack_loose_unreachable,
3015                         N_("pack loose unreachable objects")),
3016                { OPTION_CALLBACK, 0, "unpack-unreachable", NULL, N_("time"),
3017                  N_("unpack unreachable objects newer than <time>"),
3018                  PARSE_OPT_OPTARG, option_parse_unpack_unreachable },
3019                OPT_BOOL(0, "thin", &thin,
3020                         N_("create thin packs")),
3021                OPT_BOOL(0, "shallow", &shallow,
3022                         N_("create packs suitable for shallow fetches")),
3023                OPT_BOOL(0, "honor-pack-keep", &ignore_packed_keep,
3024                         N_("ignore packs that have companion .keep file")),
3025                OPT_INTEGER(0, "compression", &pack_compression_level,
3026                            N_("pack compression level")),
3027                OPT_SET_INT(0, "keep-true-parents", &grafts_replace_parents,
3028                            N_("do not hide commits by grafts"), 0),
3029                OPT_BOOL(0, "use-bitmap-index", &use_bitmap_index,
3030                         N_("use a bitmap index if available to speed up counting objects")),
3031                OPT_BOOL(0, "write-bitmap-index", &write_bitmap_index,
3032                         N_("write a bitmap index together with the pack index")),
3033                OPT_PARSE_LIST_OBJECTS_FILTER(&filter_options),
3034                { OPTION_CALLBACK, 0, "missing", NULL, N_("action"),
3035                  N_("handling for missing objects"), PARSE_OPT_NONEG,
3036                  option_parse_missing_action },
3037                OPT_BOOL(0, "exclude-promisor-objects", &exclude_promisor_objects,
3038                         N_("do not pack objects in promisor packfiles")),
3039                OPT_END(),
3040        };
3041
3042        check_replace_refs = 0;
3043
3044        reset_pack_idx_option(&pack_idx_opts);
3045        git_config(git_pack_config, NULL);
3046
3047        progress = isatty(2);
3048        argc = parse_options(argc, argv, prefix, pack_objects_options,
3049                             pack_usage, 0);
3050
3051        if (argc) {
3052                base_name = argv[0];
3053                argc--;
3054        }
3055        if (pack_to_stdout != !base_name || argc)
3056                usage_with_options(pack_usage, pack_objects_options);
3057
3058        argv_array_push(&rp, "pack-objects");
3059        if (thin) {
3060                use_internal_rev_list = 1;
3061                argv_array_push(&rp, shallow
3062                                ? "--objects-edge-aggressive"
3063                                : "--objects-edge");
3064        } else
3065                argv_array_push(&rp, "--objects");
3066
3067        if (rev_list_all) {
3068                use_internal_rev_list = 1;
3069                argv_array_push(&rp, "--all");
3070        }
3071        if (rev_list_reflog) {
3072                use_internal_rev_list = 1;
3073                argv_array_push(&rp, "--reflog");
3074        }
3075        if (rev_list_index) {
3076                use_internal_rev_list = 1;
3077                argv_array_push(&rp, "--indexed-objects");
3078        }
3079        if (rev_list_unpacked) {
3080                use_internal_rev_list = 1;
3081                argv_array_push(&rp, "--unpacked");
3082        }
3083
3084        if (exclude_promisor_objects) {
3085                use_internal_rev_list = 1;
3086                fetch_if_missing = 0;
3087                argv_array_push(&rp, "--exclude-promisor-objects");
3088        }
3089
3090        if (!reuse_object)
3091                reuse_delta = 0;
3092        if (pack_compression_level == -1)
3093                pack_compression_level = Z_DEFAULT_COMPRESSION;
3094        else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
3095                die("bad pack compression level %d", pack_compression_level);
3096
3097        if (!delta_search_threads)      /* --threads=0 means autodetect */
3098                delta_search_threads = online_cpus();
3099
3100#ifdef NO_PTHREADS
3101        if (delta_search_threads != 1)
3102                warning("no threads support, ignoring --threads");
3103#endif
3104        if (!pack_to_stdout && !pack_size_limit)
3105                pack_size_limit = pack_size_limit_cfg;
3106        if (pack_to_stdout && pack_size_limit)
3107                die("--max-pack-size cannot be used to build a pack for transfer.");
3108        if (pack_size_limit && pack_size_limit < 1024*1024) {
3109                warning("minimum pack size limit is 1 MiB");
3110                pack_size_limit = 1024*1024;
3111        }
3112
3113        if (!pack_to_stdout && thin)
3114                die("--thin cannot be used to build an indexable pack.");
3115
3116        if (keep_unreachable && unpack_unreachable)
3117                die("--keep-unreachable and --unpack-unreachable are incompatible.");
3118        if (!rev_list_all || !rev_list_reflog || !rev_list_index)
3119                unpack_unreachable_expiration = 0;
3120
3121        if (filter_options.choice) {
3122                if (!pack_to_stdout)
3123                        die("cannot use --filter without --stdout.");
3124                use_bitmap_index = 0;
3125        }
3126
3127        /*
3128         * "soft" reasons not to use bitmaps - for on-disk repack by default we want
3129         *
3130         * - to produce good pack (with bitmap index not-yet-packed objects are
3131         *   packed in suboptimal order).
3132         *
3133         * - to use more robust pack-generation codepath (avoiding possible
3134         *   bugs in bitmap code and possible bitmap index corruption).
3135         */
3136        if (!pack_to_stdout)
3137                use_bitmap_index_default = 0;
3138
3139        if (use_bitmap_index < 0)
3140                use_bitmap_index = use_bitmap_index_default;
3141
3142        /* "hard" reasons not to use bitmaps; these just won't work at all */
3143        if (!use_internal_rev_list || (!pack_to_stdout && write_bitmap_index) || is_repository_shallow())
3144                use_bitmap_index = 0;
3145
3146        if (pack_to_stdout || !rev_list_all)
3147                write_bitmap_index = 0;
3148
3149        if (progress && all_progress_implied)
3150                progress = 2;
3151
3152        prepare_packed_git();
3153        if (ignore_packed_keep) {
3154                struct packed_git *p;
3155                for (p = packed_git; p; p = p->next)
3156                        if (p->pack_local && p->pack_keep)
3157                                break;
3158                if (!p) /* no keep-able packs found */
3159                        ignore_packed_keep = 0;
3160        }
3161        if (local) {
3162                /*
3163                 * unlike ignore_packed_keep above, we do not want to
3164                 * unset "local" based on looking at packs, as it
3165                 * also covers non-local objects
3166                 */
3167                struct packed_git *p;
3168                for (p = packed_git; p; p = p->next) {
3169                        if (!p->pack_local) {
3170                                have_non_local_packs = 1;
3171                                break;
3172                        }
3173                }
3174        }
3175
3176        if (progress)
3177                progress_state = start_progress(_("Counting objects"), 0);
3178        if (!use_internal_rev_list)
3179                read_object_list_from_stdin();
3180        else {
3181                get_object_list(rp.argc, rp.argv);
3182                argv_array_clear(&rp);
3183        }
3184        cleanup_preferred_base();
3185        if (include_tag && nr_result)
3186                for_each_ref(add_ref_tag, NULL);
3187        stop_progress(&progress_state);
3188
3189        if (non_empty && !nr_result)
3190                return 0;
3191        if (nr_result)
3192                prepare_pack(window, depth);
3193        write_pack_file();
3194        if (progress)
3195                fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
3196                        " reused %"PRIu32" (delta %"PRIu32")\n",
3197                        written, written_delta, reused, reused_delta);
3198        return 0;
3199}