builtin / pack-objects.con commit Merge branch 'os/gitweb-highlight-uncaptured' (fd6db67)
   1#include "builtin.h"
   2#include "cache.h"
   3#include "attr.h"
   4#include "object.h"
   5#include "blob.h"
   6#include "commit.h"
   7#include "tag.h"
   8#include "tree.h"
   9#include "delta.h"
  10#include "pack.h"
  11#include "pack-revindex.h"
  12#include "csum-file.h"
  13#include "tree-walk.h"
  14#include "diff.h"
  15#include "revision.h"
  16#include "list-objects.h"
  17#include "progress.h"
  18#include "refs.h"
  19#include "streaming.h"
  20#include "thread-utils.h"
  21
  22static const char *pack_usage[] = {
  23        N_("git pack-objects --stdout [options...] [< ref-list | < object-list]"),
  24        N_("git pack-objects [options...] base-name [< ref-list | < object-list]"),
  25        NULL
  26};
  27
  28struct object_entry {
  29        struct pack_idx_entry idx;
  30        unsigned long size;     /* uncompressed size */
  31        struct packed_git *in_pack;     /* already in pack */
  32        off_t in_pack_offset;
  33        struct object_entry *delta;     /* delta base object */
  34        struct object_entry *delta_child; /* deltified objects who bases me */
  35        struct object_entry *delta_sibling; /* other deltified objects who
  36                                             * uses the same base as me
  37                                             */
  38        void *delta_data;       /* cached delta (uncompressed) */
  39        unsigned long delta_size;       /* delta data size (uncompressed) */
  40        unsigned long z_delta_size;     /* delta data size (compressed) */
  41        unsigned int hash;      /* name hint hash */
  42        enum object_type type;
  43        enum object_type in_pack_type;  /* could be delta */
  44        unsigned char in_pack_header_size;
  45        unsigned char preferred_base; /* we do not pack this, but is available
  46                                       * to be used as the base object to delta
  47                                       * objects against.
  48                                       */
  49        unsigned char no_try_delta;
  50        unsigned char tagged; /* near the very tip of refs */
  51        unsigned char filled; /* assigned write-order */
  52};
  53
  54/*
  55 * Objects we are going to pack are collected in objects array (dynamically
  56 * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  57 * in the order we see -- typically rev-list --objects order that gives us
  58 * nice "minimum seek" order.
  59 */
  60static struct object_entry *objects;
  61static struct pack_idx_entry **written_list;
  62static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
  63
  64static int non_empty;
  65static int reuse_delta = 1, reuse_object = 1;
  66static int keep_unreachable, unpack_unreachable, include_tag;
  67static unsigned long unpack_unreachable_expiration;
  68static int local;
  69static int incremental;
  70static int ignore_packed_keep;
  71static int allow_ofs_delta;
  72static struct pack_idx_option pack_idx_opts;
  73static const char *base_name;
  74static int progress = 1;
  75static int window = 10;
  76static unsigned long pack_size_limit;
  77static int depth = 50;
  78static int delta_search_threads;
  79static int pack_to_stdout;
  80static int num_preferred_base;
  81static struct progress *progress_state;
  82static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  83static int pack_compression_seen;
  84
  85static unsigned long delta_cache_size = 0;
  86static unsigned long max_delta_cache_size = 256 * 1024 * 1024;
  87static unsigned long cache_max_small_delta_size = 1000;
  88
  89static unsigned long window_memory_limit = 0;
  90
  91/*
  92 * The object names in objects array are hashed with this hashtable,
  93 * to help looking up the entry by object name.
  94 * This hashtable is built after all the objects are seen.
  95 */
  96static int *object_ix;
  97static int object_ix_hashsz;
  98static struct object_entry *locate_object_entry(const unsigned char *sha1);
  99
 100/*
 101 * stats
 102 */
 103static uint32_t written, written_delta;
 104static uint32_t reused, reused_delta;
 105
 106
 107static void *get_delta(struct object_entry *entry)
 108{
 109        unsigned long size, base_size, delta_size;
 110        void *buf, *base_buf, *delta_buf;
 111        enum object_type type;
 112
 113        buf = read_sha1_file(entry->idx.sha1, &type, &size);
 114        if (!buf)
 115                die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 116        base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
 117        if (!base_buf)
 118                die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 119        delta_buf = diff_delta(base_buf, base_size,
 120                               buf, size, &delta_size, 0);
 121        if (!delta_buf || delta_size != entry->delta_size)
 122                die("delta size changed");
 123        free(buf);
 124        free(base_buf);
 125        return delta_buf;
 126}
 127
 128static unsigned long do_compress(void **pptr, unsigned long size)
 129{
 130        git_zstream stream;
 131        void *in, *out;
 132        unsigned long maxsize;
 133
 134        memset(&stream, 0, sizeof(stream));
 135        git_deflate_init(&stream, pack_compression_level);
 136        maxsize = git_deflate_bound(&stream, size);
 137
 138        in = *pptr;
 139        out = xmalloc(maxsize);
 140        *pptr = out;
 141
 142        stream.next_in = in;
 143        stream.avail_in = size;
 144        stream.next_out = out;
 145        stream.avail_out = maxsize;
 146        while (git_deflate(&stream, Z_FINISH) == Z_OK)
 147                ; /* nothing */
 148        git_deflate_end(&stream);
 149
 150        free(in);
 151        return stream.total_out;
 152}
 153
 154static unsigned long write_large_blob_data(struct git_istream *st, struct sha1file *f,
 155                                           const unsigned char *sha1)
 156{
 157        git_zstream stream;
 158        unsigned char ibuf[1024 * 16];
 159        unsigned char obuf[1024 * 16];
 160        unsigned long olen = 0;
 161
 162        memset(&stream, 0, sizeof(stream));
 163        git_deflate_init(&stream, pack_compression_level);
 164
 165        for (;;) {
 166                ssize_t readlen;
 167                int zret = Z_OK;
 168                readlen = read_istream(st, ibuf, sizeof(ibuf));
 169                if (readlen == -1)
 170                        die(_("unable to read %s"), sha1_to_hex(sha1));
 171
 172                stream.next_in = ibuf;
 173                stream.avail_in = readlen;
 174                while ((stream.avail_in || readlen == 0) &&
 175                       (zret == Z_OK || zret == Z_BUF_ERROR)) {
 176                        stream.next_out = obuf;
 177                        stream.avail_out = sizeof(obuf);
 178                        zret = git_deflate(&stream, readlen ? 0 : Z_FINISH);
 179                        sha1write(f, obuf, stream.next_out - obuf);
 180                        olen += stream.next_out - obuf;
 181                }
 182                if (stream.avail_in)
 183                        die(_("deflate error (%d)"), zret);
 184                if (readlen == 0) {
 185                        if (zret != Z_STREAM_END)
 186                                die(_("deflate error (%d)"), zret);
 187                        break;
 188                }
 189        }
 190        git_deflate_end(&stream);
 191        return olen;
 192}
 193
 194/*
 195 * we are going to reuse the existing object data as is.  make
 196 * sure it is not corrupt.
 197 */
 198static int check_pack_inflate(struct packed_git *p,
 199                struct pack_window **w_curs,
 200                off_t offset,
 201                off_t len,
 202                unsigned long expect)
 203{
 204        git_zstream stream;
 205        unsigned char fakebuf[4096], *in;
 206        int st;
 207
 208        memset(&stream, 0, sizeof(stream));
 209        git_inflate_init(&stream);
 210        do {
 211                in = use_pack(p, w_curs, offset, &stream.avail_in);
 212                stream.next_in = in;
 213                stream.next_out = fakebuf;
 214                stream.avail_out = sizeof(fakebuf);
 215                st = git_inflate(&stream, Z_FINISH);
 216                offset += stream.next_in - in;
 217        } while (st == Z_OK || st == Z_BUF_ERROR);
 218        git_inflate_end(&stream);
 219        return (st == Z_STREAM_END &&
 220                stream.total_out == expect &&
 221                stream.total_in == len) ? 0 : -1;
 222}
 223
 224static void copy_pack_data(struct sha1file *f,
 225                struct packed_git *p,
 226                struct pack_window **w_curs,
 227                off_t offset,
 228                off_t len)
 229{
 230        unsigned char *in;
 231        unsigned long avail;
 232
 233        while (len) {
 234                in = use_pack(p, w_curs, offset, &avail);
 235                if (avail > len)
 236                        avail = (unsigned long)len;
 237                sha1write(f, in, avail);
 238                offset += avail;
 239                len -= avail;
 240        }
 241}
 242
 243/* Return 0 if we will bust the pack-size limit */
 244static unsigned long write_no_reuse_object(struct sha1file *f, struct object_entry *entry,
 245                                           unsigned long limit, int usable_delta)
 246{
 247        unsigned long size, datalen;
 248        unsigned char header[10], dheader[10];
 249        unsigned hdrlen;
 250        enum object_type type;
 251        void *buf;
 252        struct git_istream *st = NULL;
 253
 254        if (!usable_delta) {
 255                if (entry->type == OBJ_BLOB &&
 256                    entry->size > big_file_threshold &&
 257                    (st = open_istream(entry->idx.sha1, &type, &size, NULL)) != NULL)
 258                        buf = NULL;
 259                else {
 260                        buf = read_sha1_file(entry->idx.sha1, &type, &size);
 261                        if (!buf)
 262                                die(_("unable to read %s"), sha1_to_hex(entry->idx.sha1));
 263                }
 264                /*
 265                 * make sure no cached delta data remains from a
 266                 * previous attempt before a pack split occurred.
 267                 */
 268                free(entry->delta_data);
 269                entry->delta_data = NULL;
 270                entry->z_delta_size = 0;
 271        } else if (entry->delta_data) {
 272                size = entry->delta_size;
 273                buf = entry->delta_data;
 274                entry->delta_data = NULL;
 275                type = (allow_ofs_delta && entry->delta->idx.offset) ?
 276                        OBJ_OFS_DELTA : OBJ_REF_DELTA;
 277        } else {
 278                buf = get_delta(entry);
 279                size = entry->delta_size;
 280                type = (allow_ofs_delta && entry->delta->idx.offset) ?
 281                        OBJ_OFS_DELTA : OBJ_REF_DELTA;
 282        }
 283
 284        if (st) /* large blob case, just assume we don't compress well */
 285                datalen = size;
 286        else if (entry->z_delta_size)
 287                datalen = entry->z_delta_size;
 288        else
 289                datalen = do_compress(&buf, size);
 290
 291        /*
 292         * The object header is a byte of 'type' followed by zero or
 293         * more bytes of length.
 294         */
 295        hdrlen = encode_in_pack_object_header(type, size, header);
 296
 297        if (type == OBJ_OFS_DELTA) {
 298                /*
 299                 * Deltas with relative base contain an additional
 300                 * encoding of the relative offset for the delta
 301                 * base from this object's position in the pack.
 302                 */
 303                off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 304                unsigned pos = sizeof(dheader) - 1;
 305                dheader[pos] = ofs & 127;
 306                while (ofs >>= 7)
 307                        dheader[--pos] = 128 | (--ofs & 127);
 308                if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 309                        if (st)
 310                                close_istream(st);
 311                        free(buf);
 312                        return 0;
 313                }
 314                sha1write(f, header, hdrlen);
 315                sha1write(f, dheader + pos, sizeof(dheader) - pos);
 316                hdrlen += sizeof(dheader) - pos;
 317        } else if (type == OBJ_REF_DELTA) {
 318                /*
 319                 * Deltas with a base reference contain
 320                 * an additional 20 bytes for the base sha1.
 321                 */
 322                if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 323                        if (st)
 324                                close_istream(st);
 325                        free(buf);
 326                        return 0;
 327                }
 328                sha1write(f, header, hdrlen);
 329                sha1write(f, entry->delta->idx.sha1, 20);
 330                hdrlen += 20;
 331        } else {
 332                if (limit && hdrlen + datalen + 20 >= limit) {
 333                        if (st)
 334                                close_istream(st);
 335                        free(buf);
 336                        return 0;
 337                }
 338                sha1write(f, header, hdrlen);
 339        }
 340        if (st) {
 341                datalen = write_large_blob_data(st, f, entry->idx.sha1);
 342                close_istream(st);
 343        } else {
 344                sha1write(f, buf, datalen);
 345                free(buf);
 346        }
 347
 348        return hdrlen + datalen;
 349}
 350
 351/* Return 0 if we will bust the pack-size limit */
 352static unsigned long write_reuse_object(struct sha1file *f, struct object_entry *entry,
 353                                        unsigned long limit, int usable_delta)
 354{
 355        struct packed_git *p = entry->in_pack;
 356        struct pack_window *w_curs = NULL;
 357        struct revindex_entry *revidx;
 358        off_t offset;
 359        enum object_type type = entry->type;
 360        unsigned long datalen;
 361        unsigned char header[10], dheader[10];
 362        unsigned hdrlen;
 363
 364        if (entry->delta)
 365                type = (allow_ofs_delta && entry->delta->idx.offset) ?
 366                        OBJ_OFS_DELTA : OBJ_REF_DELTA;
 367        hdrlen = encode_in_pack_object_header(type, entry->size, header);
 368
 369        offset = entry->in_pack_offset;
 370        revidx = find_pack_revindex(p, offset);
 371        datalen = revidx[1].offset - offset;
 372        if (!pack_to_stdout && p->index_version > 1 &&
 373            check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 374                error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 375                unuse_pack(&w_curs);
 376                return write_no_reuse_object(f, entry, limit, usable_delta);
 377        }
 378
 379        offset += entry->in_pack_header_size;
 380        datalen -= entry->in_pack_header_size;
 381
 382        if (!pack_to_stdout && p->index_version == 1 &&
 383            check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
 384                error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 385                unuse_pack(&w_curs);
 386                return write_no_reuse_object(f, entry, limit, usable_delta);
 387        }
 388
 389        if (type == OBJ_OFS_DELTA) {
 390                off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 391                unsigned pos = sizeof(dheader) - 1;
 392                dheader[pos] = ofs & 127;
 393                while (ofs >>= 7)
 394                        dheader[--pos] = 128 | (--ofs & 127);
 395                if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 396                        unuse_pack(&w_curs);
 397                        return 0;
 398                }
 399                sha1write(f, header, hdrlen);
 400                sha1write(f, dheader + pos, sizeof(dheader) - pos);
 401                hdrlen += sizeof(dheader) - pos;
 402                reused_delta++;
 403        } else if (type == OBJ_REF_DELTA) {
 404                if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 405                        unuse_pack(&w_curs);
 406                        return 0;
 407                }
 408                sha1write(f, header, hdrlen);
 409                sha1write(f, entry->delta->idx.sha1, 20);
 410                hdrlen += 20;
 411                reused_delta++;
 412        } else {
 413                if (limit && hdrlen + datalen + 20 >= limit) {
 414                        unuse_pack(&w_curs);
 415                        return 0;
 416                }
 417                sha1write(f, header, hdrlen);
 418        }
 419        copy_pack_data(f, p, &w_curs, offset, datalen);
 420        unuse_pack(&w_curs);
 421        reused++;
 422        return hdrlen + datalen;
 423}
 424
 425/* Return 0 if we will bust the pack-size limit */
 426static unsigned long write_object(struct sha1file *f,
 427                                  struct object_entry *entry,
 428                                  off_t write_offset)
 429{
 430        unsigned long limit, len;
 431        int usable_delta, to_reuse;
 432
 433        if (!pack_to_stdout)
 434                crc32_begin(f);
 435
 436        /* apply size limit if limited packsize and not first object */
 437        if (!pack_size_limit || !nr_written)
 438                limit = 0;
 439        else if (pack_size_limit <= write_offset)
 440                /*
 441                 * the earlier object did not fit the limit; avoid
 442                 * mistaking this with unlimited (i.e. limit = 0).
 443                 */
 444                limit = 1;
 445        else
 446                limit = pack_size_limit - write_offset;
 447
 448        if (!entry->delta)
 449                usable_delta = 0;       /* no delta */
 450        else if (!pack_size_limit)
 451               usable_delta = 1;        /* unlimited packfile */
 452        else if (entry->delta->idx.offset == (off_t)-1)
 453                usable_delta = 0;       /* base was written to another pack */
 454        else if (entry->delta->idx.offset)
 455                usable_delta = 1;       /* base already exists in this pack */
 456        else
 457                usable_delta = 0;       /* base could end up in another pack */
 458
 459        if (!reuse_object)
 460                to_reuse = 0;   /* explicit */
 461        else if (!entry->in_pack)
 462                to_reuse = 0;   /* can't reuse what we don't have */
 463        else if (entry->type == OBJ_REF_DELTA || entry->type == OBJ_OFS_DELTA)
 464                                /* check_object() decided it for us ... */
 465                to_reuse = usable_delta;
 466                                /* ... but pack split may override that */
 467        else if (entry->type != entry->in_pack_type)
 468                to_reuse = 0;   /* pack has delta which is unusable */
 469        else if (entry->delta)
 470                to_reuse = 0;   /* we want to pack afresh */
 471        else
 472                to_reuse = 1;   /* we have it in-pack undeltified,
 473                                 * and we do not need to deltify it.
 474                                 */
 475
 476        if (!to_reuse)
 477                len = write_no_reuse_object(f, entry, limit, usable_delta);
 478        else
 479                len = write_reuse_object(f, entry, limit, usable_delta);
 480        if (!len)
 481                return 0;
 482
 483        if (usable_delta)
 484                written_delta++;
 485        written++;
 486        if (!pack_to_stdout)
 487                entry->idx.crc32 = crc32_end(f);
 488        return len;
 489}
 490
 491enum write_one_status {
 492        WRITE_ONE_SKIP = -1, /* already written */
 493        WRITE_ONE_BREAK = 0, /* writing this will bust the limit; not written */
 494        WRITE_ONE_WRITTEN = 1, /* normal */
 495        WRITE_ONE_RECURSIVE = 2 /* already scheduled to be written */
 496};
 497
 498static enum write_one_status write_one(struct sha1file *f,
 499                                       struct object_entry *e,
 500                                       off_t *offset)
 501{
 502        unsigned long size;
 503        int recursing;
 504
 505        /*
 506         * we set offset to 1 (which is an impossible value) to mark
 507         * the fact that this object is involved in "write its base
 508         * first before writing a deltified object" recursion.
 509         */
 510        recursing = (e->idx.offset == 1);
 511        if (recursing) {
 512                warning("recursive delta detected for object %s",
 513                        sha1_to_hex(e->idx.sha1));
 514                return WRITE_ONE_RECURSIVE;
 515        } else if (e->idx.offset || e->preferred_base) {
 516                /* offset is non zero if object is written already. */
 517                return WRITE_ONE_SKIP;
 518        }
 519
 520        /* if we are deltified, write out base object first. */
 521        if (e->delta) {
 522                e->idx.offset = 1; /* now recurse */
 523                switch (write_one(f, e->delta, offset)) {
 524                case WRITE_ONE_RECURSIVE:
 525                        /* we cannot depend on this one */
 526                        e->delta = NULL;
 527                        break;
 528                default:
 529                        break;
 530                case WRITE_ONE_BREAK:
 531                        e->idx.offset = recursing;
 532                        return WRITE_ONE_BREAK;
 533                }
 534        }
 535
 536        e->idx.offset = *offset;
 537        size = write_object(f, e, *offset);
 538        if (!size) {
 539                e->idx.offset = recursing;
 540                return WRITE_ONE_BREAK;
 541        }
 542        written_list[nr_written++] = &e->idx;
 543
 544        /* make sure off_t is sufficiently large not to wrap */
 545        if (signed_add_overflows(*offset, size))
 546                die("pack too large for current definition of off_t");
 547        *offset += size;
 548        return WRITE_ONE_WRITTEN;
 549}
 550
 551static int mark_tagged(const char *path, const unsigned char *sha1, int flag,
 552                       void *cb_data)
 553{
 554        unsigned char peeled[20];
 555        struct object_entry *entry = locate_object_entry(sha1);
 556
 557        if (entry)
 558                entry->tagged = 1;
 559        if (!peel_ref(path, peeled)) {
 560                entry = locate_object_entry(peeled);
 561                if (entry)
 562                        entry->tagged = 1;
 563        }
 564        return 0;
 565}
 566
 567static inline void add_to_write_order(struct object_entry **wo,
 568                               unsigned int *endp,
 569                               struct object_entry *e)
 570{
 571        if (e->filled)
 572                return;
 573        wo[(*endp)++] = e;
 574        e->filled = 1;
 575}
 576
 577static void add_descendants_to_write_order(struct object_entry **wo,
 578                                           unsigned int *endp,
 579                                           struct object_entry *e)
 580{
 581        int add_to_order = 1;
 582        while (e) {
 583                if (add_to_order) {
 584                        struct object_entry *s;
 585                        /* add this node... */
 586                        add_to_write_order(wo, endp, e);
 587                        /* all its siblings... */
 588                        for (s = e->delta_sibling; s; s = s->delta_sibling) {
 589                                add_to_write_order(wo, endp, s);
 590                        }
 591                }
 592                /* drop down a level to add left subtree nodes if possible */
 593                if (e->delta_child) {
 594                        add_to_order = 1;
 595                        e = e->delta_child;
 596                } else {
 597                        add_to_order = 0;
 598                        /* our sibling might have some children, it is next */
 599                        if (e->delta_sibling) {
 600                                e = e->delta_sibling;
 601                                continue;
 602                        }
 603                        /* go back to our parent node */
 604                        e = e->delta;
 605                        while (e && !e->delta_sibling) {
 606                                /* we're on the right side of a subtree, keep
 607                                 * going up until we can go right again */
 608                                e = e->delta;
 609                        }
 610                        if (!e) {
 611                                /* done- we hit our original root node */
 612                                return;
 613                        }
 614                        /* pass it off to sibling at this level */
 615                        e = e->delta_sibling;
 616                }
 617        };
 618}
 619
 620static void add_family_to_write_order(struct object_entry **wo,
 621                                      unsigned int *endp,
 622                                      struct object_entry *e)
 623{
 624        struct object_entry *root;
 625
 626        for (root = e; root->delta; root = root->delta)
 627                ; /* nothing */
 628        add_descendants_to_write_order(wo, endp, root);
 629}
 630
 631static struct object_entry **compute_write_order(void)
 632{
 633        unsigned int i, wo_end, last_untagged;
 634
 635        struct object_entry **wo = xmalloc(nr_objects * sizeof(*wo));
 636
 637        for (i = 0; i < nr_objects; i++) {
 638                objects[i].tagged = 0;
 639                objects[i].filled = 0;
 640                objects[i].delta_child = NULL;
 641                objects[i].delta_sibling = NULL;
 642        }
 643
 644        /*
 645         * Fully connect delta_child/delta_sibling network.
 646         * Make sure delta_sibling is sorted in the original
 647         * recency order.
 648         */
 649        for (i = nr_objects; i > 0;) {
 650                struct object_entry *e = &objects[--i];
 651                if (!e->delta)
 652                        continue;
 653                /* Mark me as the first child */
 654                e->delta_sibling = e->delta->delta_child;
 655                e->delta->delta_child = e;
 656        }
 657
 658        /*
 659         * Mark objects that are at the tip of tags.
 660         */
 661        for_each_tag_ref(mark_tagged, NULL);
 662
 663        /*
 664         * Give the objects in the original recency order until
 665         * we see a tagged tip.
 666         */
 667        for (i = wo_end = 0; i < nr_objects; i++) {
 668                if (objects[i].tagged)
 669                        break;
 670                add_to_write_order(wo, &wo_end, &objects[i]);
 671        }
 672        last_untagged = i;
 673
 674        /*
 675         * Then fill all the tagged tips.
 676         */
 677        for (; i < nr_objects; i++) {
 678                if (objects[i].tagged)
 679                        add_to_write_order(wo, &wo_end, &objects[i]);
 680        }
 681
 682        /*
 683         * And then all remaining commits and tags.
 684         */
 685        for (i = last_untagged; i < nr_objects; i++) {
 686                if (objects[i].type != OBJ_COMMIT &&
 687                    objects[i].type != OBJ_TAG)
 688                        continue;
 689                add_to_write_order(wo, &wo_end, &objects[i]);
 690        }
 691
 692        /*
 693         * And then all the trees.
 694         */
 695        for (i = last_untagged; i < nr_objects; i++) {
 696                if (objects[i].type != OBJ_TREE)
 697                        continue;
 698                add_to_write_order(wo, &wo_end, &objects[i]);
 699        }
 700
 701        /*
 702         * Finally all the rest in really tight order
 703         */
 704        for (i = last_untagged; i < nr_objects; i++) {
 705                if (!objects[i].filled)
 706                        add_family_to_write_order(wo, &wo_end, &objects[i]);
 707        }
 708
 709        if (wo_end != nr_objects)
 710                die("ordered %u objects, expected %"PRIu32, wo_end, nr_objects);
 711
 712        return wo;
 713}
 714
 715static void write_pack_file(void)
 716{
 717        uint32_t i = 0, j;
 718        struct sha1file *f;
 719        off_t offset;
 720        uint32_t nr_remaining = nr_result;
 721        time_t last_mtime = 0;
 722        struct object_entry **write_order;
 723
 724        if (progress > pack_to_stdout)
 725                progress_state = start_progress("Writing objects", nr_result);
 726        written_list = xmalloc(nr_objects * sizeof(*written_list));
 727        write_order = compute_write_order();
 728
 729        do {
 730                unsigned char sha1[20];
 731                char *pack_tmp_name = NULL;
 732
 733                if (pack_to_stdout)
 734                        f = sha1fd_throughput(1, "<stdout>", progress_state);
 735                else
 736                        f = create_tmp_packfile(&pack_tmp_name);
 737
 738                offset = write_pack_header(f, nr_remaining);
 739                if (!offset)
 740                        die_errno("unable to write pack header");
 741                nr_written = 0;
 742                for (; i < nr_objects; i++) {
 743                        struct object_entry *e = write_order[i];
 744                        if (write_one(f, e, &offset) == WRITE_ONE_BREAK)
 745                                break;
 746                        display_progress(progress_state, written);
 747                }
 748
 749                /*
 750                 * Did we write the wrong # entries in the header?
 751                 * If so, rewrite it like in fast-import
 752                 */
 753                if (pack_to_stdout) {
 754                        sha1close(f, sha1, CSUM_CLOSE);
 755                } else if (nr_written == nr_remaining) {
 756                        sha1close(f, sha1, CSUM_FSYNC);
 757                } else {
 758                        int fd = sha1close(f, sha1, 0);
 759                        fixup_pack_header_footer(fd, sha1, pack_tmp_name,
 760                                                 nr_written, sha1, offset);
 761                        close(fd);
 762                }
 763
 764                if (!pack_to_stdout) {
 765                        struct stat st;
 766                        char tmpname[PATH_MAX];
 767
 768                        /*
 769                         * Packs are runtime accessed in their mtime
 770                         * order since newer packs are more likely to contain
 771                         * younger objects.  So if we are creating multiple
 772                         * packs then we should modify the mtime of later ones
 773                         * to preserve this property.
 774                         */
 775                        if (stat(pack_tmp_name, &st) < 0) {
 776                                warning("failed to stat %s: %s",
 777                                        pack_tmp_name, strerror(errno));
 778                        } else if (!last_mtime) {
 779                                last_mtime = st.st_mtime;
 780                        } else {
 781                                struct utimbuf utb;
 782                                utb.actime = st.st_atime;
 783                                utb.modtime = --last_mtime;
 784                                if (utime(pack_tmp_name, &utb) < 0)
 785                                        warning("failed utime() on %s: %s",
 786                                                tmpname, strerror(errno));
 787                        }
 788
 789                        /* Enough space for "-<sha-1>.pack"? */
 790                        if (sizeof(tmpname) <= strlen(base_name) + 50)
 791                                die("pack base name '%s' too long", base_name);
 792                        snprintf(tmpname, sizeof(tmpname), "%s-", base_name);
 793                        finish_tmp_packfile(tmpname, pack_tmp_name,
 794                                            written_list, nr_written,
 795                                            &pack_idx_opts, sha1);
 796                        free(pack_tmp_name);
 797                        puts(sha1_to_hex(sha1));
 798                }
 799
 800                /* mark written objects as written to previous pack */
 801                for (j = 0; j < nr_written; j++) {
 802                        written_list[j]->offset = (off_t)-1;
 803                }
 804                nr_remaining -= nr_written;
 805        } while (nr_remaining && i < nr_objects);
 806
 807        free(written_list);
 808        free(write_order);
 809        stop_progress(&progress_state);
 810        if (written != nr_result)
 811                die("wrote %"PRIu32" objects while expecting %"PRIu32,
 812                        written, nr_result);
 813}
 814
 815static int locate_object_entry_hash(const unsigned char *sha1)
 816{
 817        int i;
 818        unsigned int ui;
 819        memcpy(&ui, sha1, sizeof(unsigned int));
 820        i = ui % object_ix_hashsz;
 821        while (0 < object_ix[i]) {
 822                if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 823                        return i;
 824                if (++i == object_ix_hashsz)
 825                        i = 0;
 826        }
 827        return -1 - i;
 828}
 829
 830static struct object_entry *locate_object_entry(const unsigned char *sha1)
 831{
 832        int i;
 833
 834        if (!object_ix_hashsz)
 835                return NULL;
 836
 837        i = locate_object_entry_hash(sha1);
 838        if (0 <= i)
 839                return &objects[object_ix[i]-1];
 840        return NULL;
 841}
 842
 843static void rehash_objects(void)
 844{
 845        uint32_t i;
 846        struct object_entry *oe;
 847
 848        object_ix_hashsz = nr_objects * 3;
 849        if (object_ix_hashsz < 1024)
 850                object_ix_hashsz = 1024;
 851        object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 852        memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 853        for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 854                int ix = locate_object_entry_hash(oe->idx.sha1);
 855                if (0 <= ix)
 856                        continue;
 857                ix = -1 - ix;
 858                object_ix[ix] = i + 1;
 859        }
 860}
 861
 862static unsigned name_hash(const char *name)
 863{
 864        unsigned c, hash = 0;
 865
 866        if (!name)
 867                return 0;
 868
 869        /*
 870         * This effectively just creates a sortable number from the
 871         * last sixteen non-whitespace characters. Last characters
 872         * count "most", so things that end in ".c" sort together.
 873         */
 874        while ((c = *name++) != 0) {
 875                if (isspace(c))
 876                        continue;
 877                hash = (hash >> 2) + (c << 24);
 878        }
 879        return hash;
 880}
 881
 882static void setup_delta_attr_check(struct git_attr_check *check)
 883{
 884        static struct git_attr *attr_delta;
 885
 886        if (!attr_delta)
 887                attr_delta = git_attr("delta");
 888
 889        check[0].attr = attr_delta;
 890}
 891
 892static int no_try_delta(const char *path)
 893{
 894        struct git_attr_check check[1];
 895
 896        setup_delta_attr_check(check);
 897        if (git_check_attr(path, ARRAY_SIZE(check), check))
 898                return 0;
 899        if (ATTR_FALSE(check->value))
 900                return 1;
 901        return 0;
 902}
 903
 904static int add_object_entry(const unsigned char *sha1, enum object_type type,
 905                            const char *name, int exclude)
 906{
 907        struct object_entry *entry;
 908        struct packed_git *p, *found_pack = NULL;
 909        off_t found_offset = 0;
 910        int ix;
 911        unsigned hash = name_hash(name);
 912
 913        ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 914        if (ix >= 0) {
 915                if (exclude) {
 916                        entry = objects + object_ix[ix] - 1;
 917                        if (!entry->preferred_base)
 918                                nr_result--;
 919                        entry->preferred_base = 1;
 920                }
 921                return 0;
 922        }
 923
 924        if (!exclude && local && has_loose_object_nonlocal(sha1))
 925                return 0;
 926
 927        for (p = packed_git; p; p = p->next) {
 928                off_t offset = find_pack_entry_one(sha1, p);
 929                if (offset) {
 930                        if (!found_pack) {
 931                                if (!is_pack_valid(p)) {
 932                                        warning("packfile %s cannot be accessed", p->pack_name);
 933                                        continue;
 934                                }
 935                                found_offset = offset;
 936                                found_pack = p;
 937                        }
 938                        if (exclude)
 939                                break;
 940                        if (incremental)
 941                                return 0;
 942                        if (local && !p->pack_local)
 943                                return 0;
 944                        if (ignore_packed_keep && p->pack_local && p->pack_keep)
 945                                return 0;
 946                }
 947        }
 948
 949        if (nr_objects >= nr_alloc) {
 950                nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 951                objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 952        }
 953
 954        entry = objects + nr_objects++;
 955        memset(entry, 0, sizeof(*entry));
 956        hashcpy(entry->idx.sha1, sha1);
 957        entry->hash = hash;
 958        if (type)
 959                entry->type = type;
 960        if (exclude)
 961                entry->preferred_base = 1;
 962        else
 963                nr_result++;
 964        if (found_pack) {
 965                entry->in_pack = found_pack;
 966                entry->in_pack_offset = found_offset;
 967        }
 968
 969        if (object_ix_hashsz * 3 <= nr_objects * 4)
 970                rehash_objects();
 971        else
 972                object_ix[-1 - ix] = nr_objects;
 973
 974        display_progress(progress_state, nr_objects);
 975
 976        if (name && no_try_delta(name))
 977                entry->no_try_delta = 1;
 978
 979        return 1;
 980}
 981
 982struct pbase_tree_cache {
 983        unsigned char sha1[20];
 984        int ref;
 985        int temporary;
 986        void *tree_data;
 987        unsigned long tree_size;
 988};
 989
 990static struct pbase_tree_cache *(pbase_tree_cache[256]);
 991static int pbase_tree_cache_ix(const unsigned char *sha1)
 992{
 993        return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 994}
 995static int pbase_tree_cache_ix_incr(int ix)
 996{
 997        return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 998}
 999
1000static struct pbase_tree {
1001        struct pbase_tree *next;
1002        /* This is a phony "cache" entry; we are not
1003         * going to evict it nor find it through _get()
1004         * mechanism -- this is for the toplevel node that
1005         * would almost always change with any commit.
1006         */
1007        struct pbase_tree_cache pcache;
1008} *pbase_tree;
1009
1010static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
1011{
1012        struct pbase_tree_cache *ent, *nent;
1013        void *data;
1014        unsigned long size;
1015        enum object_type type;
1016        int neigh;
1017        int my_ix = pbase_tree_cache_ix(sha1);
1018        int available_ix = -1;
1019
1020        /* pbase-tree-cache acts as a limited hashtable.
1021         * your object will be found at your index or within a few
1022         * slots after that slot if it is cached.
1023         */
1024        for (neigh = 0; neigh < 8; neigh++) {
1025                ent = pbase_tree_cache[my_ix];
1026                if (ent && !hashcmp(ent->sha1, sha1)) {
1027                        ent->ref++;
1028                        return ent;
1029                }
1030                else if (((available_ix < 0) && (!ent || !ent->ref)) ||
1031                         ((0 <= available_ix) &&
1032                          (!ent && pbase_tree_cache[available_ix])))
1033                        available_ix = my_ix;
1034                if (!ent)
1035                        break;
1036                my_ix = pbase_tree_cache_ix_incr(my_ix);
1037        }
1038
1039        /* Did not find one.  Either we got a bogus request or
1040         * we need to read and perhaps cache.
1041         */
1042        data = read_sha1_file(sha1, &type, &size);
1043        if (!data)
1044                return NULL;
1045        if (type != OBJ_TREE) {
1046                free(data);
1047                return NULL;
1048        }
1049
1050        /* We need to either cache or return a throwaway copy */
1051
1052        if (available_ix < 0)
1053                ent = NULL;
1054        else {
1055                ent = pbase_tree_cache[available_ix];
1056                my_ix = available_ix;
1057        }
1058
1059        if (!ent) {
1060                nent = xmalloc(sizeof(*nent));
1061                nent->temporary = (available_ix < 0);
1062        }
1063        else {
1064                /* evict and reuse */
1065                free(ent->tree_data);
1066                nent = ent;
1067        }
1068        hashcpy(nent->sha1, sha1);
1069        nent->tree_data = data;
1070        nent->tree_size = size;
1071        nent->ref = 1;
1072        if (!nent->temporary)
1073                pbase_tree_cache[my_ix] = nent;
1074        return nent;
1075}
1076
1077static void pbase_tree_put(struct pbase_tree_cache *cache)
1078{
1079        if (!cache->temporary) {
1080                cache->ref--;
1081                return;
1082        }
1083        free(cache->tree_data);
1084        free(cache);
1085}
1086
1087static int name_cmp_len(const char *name)
1088{
1089        int i;
1090        for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
1091                ;
1092        return i;
1093}
1094
1095static void add_pbase_object(struct tree_desc *tree,
1096                             const char *name,
1097                             int cmplen,
1098                             const char *fullname)
1099{
1100        struct name_entry entry;
1101        int cmp;
1102
1103        while (tree_entry(tree,&entry)) {
1104                if (S_ISGITLINK(entry.mode))
1105                        continue;
1106                cmp = tree_entry_len(&entry) != cmplen ? 1 :
1107                      memcmp(name, entry.path, cmplen);
1108                if (cmp > 0)
1109                        continue;
1110                if (cmp < 0)
1111                        return;
1112                if (name[cmplen] != '/') {
1113                        add_object_entry(entry.sha1,
1114                                         object_type(entry.mode),
1115                                         fullname, 1);
1116                        return;
1117                }
1118                if (S_ISDIR(entry.mode)) {
1119                        struct tree_desc sub;
1120                        struct pbase_tree_cache *tree;
1121                        const char *down = name+cmplen+1;
1122                        int downlen = name_cmp_len(down);
1123
1124                        tree = pbase_tree_get(entry.sha1);
1125                        if (!tree)
1126                                return;
1127                        init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1128
1129                        add_pbase_object(&sub, down, downlen, fullname);
1130                        pbase_tree_put(tree);
1131                }
1132        }
1133}
1134
1135static unsigned *done_pbase_paths;
1136static int done_pbase_paths_num;
1137static int done_pbase_paths_alloc;
1138static int done_pbase_path_pos(unsigned hash)
1139{
1140        int lo = 0;
1141        int hi = done_pbase_paths_num;
1142        while (lo < hi) {
1143                int mi = (hi + lo) / 2;
1144                if (done_pbase_paths[mi] == hash)
1145                        return mi;
1146                if (done_pbase_paths[mi] < hash)
1147                        hi = mi;
1148                else
1149                        lo = mi + 1;
1150        }
1151        return -lo-1;
1152}
1153
1154static int check_pbase_path(unsigned hash)
1155{
1156        int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
1157        if (0 <= pos)
1158                return 1;
1159        pos = -pos - 1;
1160        if (done_pbase_paths_alloc <= done_pbase_paths_num) {
1161                done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
1162                done_pbase_paths = xrealloc(done_pbase_paths,
1163                                            done_pbase_paths_alloc *
1164                                            sizeof(unsigned));
1165        }
1166        done_pbase_paths_num++;
1167        if (pos < done_pbase_paths_num)
1168                memmove(done_pbase_paths + pos + 1,
1169                        done_pbase_paths + pos,
1170                        (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
1171        done_pbase_paths[pos] = hash;
1172        return 0;
1173}
1174
1175static void add_preferred_base_object(const char *name)
1176{
1177        struct pbase_tree *it;
1178        int cmplen;
1179        unsigned hash = name_hash(name);
1180
1181        if (!num_preferred_base || check_pbase_path(hash))
1182                return;
1183
1184        cmplen = name_cmp_len(name);
1185        for (it = pbase_tree; it; it = it->next) {
1186                if (cmplen == 0) {
1187                        add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
1188                }
1189                else {
1190                        struct tree_desc tree;
1191                        init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1192                        add_pbase_object(&tree, name, cmplen, name);
1193                }
1194        }
1195}
1196
1197static void add_preferred_base(unsigned char *sha1)
1198{
1199        struct pbase_tree *it;
1200        void *data;
1201        unsigned long size;
1202        unsigned char tree_sha1[20];
1203
1204        if (window <= num_preferred_base++)
1205                return;
1206
1207        data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
1208        if (!data)
1209                return;
1210
1211        for (it = pbase_tree; it; it = it->next) {
1212                if (!hashcmp(it->pcache.sha1, tree_sha1)) {
1213                        free(data);
1214                        return;
1215                }
1216        }
1217
1218        it = xcalloc(1, sizeof(*it));
1219        it->next = pbase_tree;
1220        pbase_tree = it;
1221
1222        hashcpy(it->pcache.sha1, tree_sha1);
1223        it->pcache.tree_data = data;
1224        it->pcache.tree_size = size;
1225}
1226
1227static void cleanup_preferred_base(void)
1228{
1229        struct pbase_tree *it;
1230        unsigned i;
1231
1232        it = pbase_tree;
1233        pbase_tree = NULL;
1234        while (it) {
1235                struct pbase_tree *this = it;
1236                it = this->next;
1237                free(this->pcache.tree_data);
1238                free(this);
1239        }
1240
1241        for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1242                if (!pbase_tree_cache[i])
1243                        continue;
1244                free(pbase_tree_cache[i]->tree_data);
1245                free(pbase_tree_cache[i]);
1246                pbase_tree_cache[i] = NULL;
1247        }
1248
1249        free(done_pbase_paths);
1250        done_pbase_paths = NULL;
1251        done_pbase_paths_num = done_pbase_paths_alloc = 0;
1252}
1253
1254static void check_object(struct object_entry *entry)
1255{
1256        if (entry->in_pack) {
1257                struct packed_git *p = entry->in_pack;
1258                struct pack_window *w_curs = NULL;
1259                const unsigned char *base_ref = NULL;
1260                struct object_entry *base_entry;
1261                unsigned long used, used_0;
1262                unsigned long avail;
1263                off_t ofs;
1264                unsigned char *buf, c;
1265
1266                buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1267
1268                /*
1269                 * We want in_pack_type even if we do not reuse delta
1270                 * since non-delta representations could still be reused.
1271                 */
1272                used = unpack_object_header_buffer(buf, avail,
1273                                                   &entry->in_pack_type,
1274                                                   &entry->size);
1275                if (used == 0)
1276                        goto give_up;
1277
1278                /*
1279                 * Determine if this is a delta and if so whether we can
1280                 * reuse it or not.  Otherwise let's find out as cheaply as
1281                 * possible what the actual type and size for this object is.
1282                 */
1283                switch (entry->in_pack_type) {
1284                default:
1285                        /* Not a delta hence we've already got all we need. */
1286                        entry->type = entry->in_pack_type;
1287                        entry->in_pack_header_size = used;
1288                        if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1289                                goto give_up;
1290                        unuse_pack(&w_curs);
1291                        return;
1292                case OBJ_REF_DELTA:
1293                        if (reuse_delta && !entry->preferred_base)
1294                                base_ref = use_pack(p, &w_curs,
1295                                                entry->in_pack_offset + used, NULL);
1296                        entry->in_pack_header_size = used + 20;
1297                        break;
1298                case OBJ_OFS_DELTA:
1299                        buf = use_pack(p, &w_curs,
1300                                       entry->in_pack_offset + used, NULL);
1301                        used_0 = 0;
1302                        c = buf[used_0++];
1303                        ofs = c & 127;
1304                        while (c & 128) {
1305                                ofs += 1;
1306                                if (!ofs || MSB(ofs, 7)) {
1307                                        error("delta base offset overflow in pack for %s",
1308                                              sha1_to_hex(entry->idx.sha1));
1309                                        goto give_up;
1310                                }
1311                                c = buf[used_0++];
1312                                ofs = (ofs << 7) + (c & 127);
1313                        }
1314                        ofs = entry->in_pack_offset - ofs;
1315                        if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1316                                error("delta base offset out of bound for %s",
1317                                      sha1_to_hex(entry->idx.sha1));
1318                                goto give_up;
1319                        }
1320                        if (reuse_delta && !entry->preferred_base) {
1321                                struct revindex_entry *revidx;
1322                                revidx = find_pack_revindex(p, ofs);
1323                                if (!revidx)
1324                                        goto give_up;
1325                                base_ref = nth_packed_object_sha1(p, revidx->nr);
1326                        }
1327                        entry->in_pack_header_size = used + used_0;
1328                        break;
1329                }
1330
1331                if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1332                        /*
1333                         * If base_ref was set above that means we wish to
1334                         * reuse delta data, and we even found that base
1335                         * in the list of objects we want to pack. Goodie!
1336                         *
1337                         * Depth value does not matter - find_deltas() will
1338                         * never consider reused delta as the base object to
1339                         * deltify other objects against, in order to avoid
1340                         * circular deltas.
1341                         */
1342                        entry->type = entry->in_pack_type;
1343                        entry->delta = base_entry;
1344                        entry->delta_size = entry->size;
1345                        entry->delta_sibling = base_entry->delta_child;
1346                        base_entry->delta_child = entry;
1347                        unuse_pack(&w_curs);
1348                        return;
1349                }
1350
1351                if (entry->type) {
1352                        /*
1353                         * This must be a delta and we already know what the
1354                         * final object type is.  Let's extract the actual
1355                         * object size from the delta header.
1356                         */
1357                        entry->size = get_size_from_delta(p, &w_curs,
1358                                        entry->in_pack_offset + entry->in_pack_header_size);
1359                        if (entry->size == 0)
1360                                goto give_up;
1361                        unuse_pack(&w_curs);
1362                        return;
1363                }
1364
1365                /*
1366                 * No choice but to fall back to the recursive delta walk
1367                 * with sha1_object_info() to find about the object type
1368                 * at this point...
1369                 */
1370                give_up:
1371                unuse_pack(&w_curs);
1372        }
1373
1374        entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1375        /*
1376         * The error condition is checked in prepare_pack().  This is
1377         * to permit a missing preferred base object to be ignored
1378         * as a preferred base.  Doing so can result in a larger
1379         * pack file, but the transfer will still take place.
1380         */
1381}
1382
1383static int pack_offset_sort(const void *_a, const void *_b)
1384{
1385        const struct object_entry *a = *(struct object_entry **)_a;
1386        const struct object_entry *b = *(struct object_entry **)_b;
1387
1388        /* avoid filesystem trashing with loose objects */
1389        if (!a->in_pack && !b->in_pack)
1390                return hashcmp(a->idx.sha1, b->idx.sha1);
1391
1392        if (a->in_pack < b->in_pack)
1393                return -1;
1394        if (a->in_pack > b->in_pack)
1395                return 1;
1396        return a->in_pack_offset < b->in_pack_offset ? -1 :
1397                        (a->in_pack_offset > b->in_pack_offset);
1398}
1399
1400static void get_object_details(void)
1401{
1402        uint32_t i;
1403        struct object_entry **sorted_by_offset;
1404
1405        sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1406        for (i = 0; i < nr_objects; i++)
1407                sorted_by_offset[i] = objects + i;
1408        qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1409
1410        for (i = 0; i < nr_objects; i++) {
1411                struct object_entry *entry = sorted_by_offset[i];
1412                check_object(entry);
1413                if (big_file_threshold < entry->size)
1414                        entry->no_try_delta = 1;
1415        }
1416
1417        free(sorted_by_offset);
1418}
1419
1420/*
1421 * We search for deltas in a list sorted by type, by filename hash, and then
1422 * by size, so that we see progressively smaller and smaller files.
1423 * That's because we prefer deltas to be from the bigger file
1424 * to the smaller -- deletes are potentially cheaper, but perhaps
1425 * more importantly, the bigger file is likely the more recent
1426 * one.  The deepest deltas are therefore the oldest objects which are
1427 * less susceptible to be accessed often.
1428 */
1429static int type_size_sort(const void *_a, const void *_b)
1430{
1431        const struct object_entry *a = *(struct object_entry **)_a;
1432        const struct object_entry *b = *(struct object_entry **)_b;
1433
1434        if (a->type > b->type)
1435                return -1;
1436        if (a->type < b->type)
1437                return 1;
1438        if (a->hash > b->hash)
1439                return -1;
1440        if (a->hash < b->hash)
1441                return 1;
1442        if (a->preferred_base > b->preferred_base)
1443                return -1;
1444        if (a->preferred_base < b->preferred_base)
1445                return 1;
1446        if (a->size > b->size)
1447                return -1;
1448        if (a->size < b->size)
1449                return 1;
1450        return a < b ? -1 : (a > b);  /* newest first */
1451}
1452
1453struct unpacked {
1454        struct object_entry *entry;
1455        void *data;
1456        struct delta_index *index;
1457        unsigned depth;
1458};
1459
1460static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1461                           unsigned long delta_size)
1462{
1463        if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1464                return 0;
1465
1466        if (delta_size < cache_max_small_delta_size)
1467                return 1;
1468
1469        /* cache delta, if objects are large enough compared to delta size */
1470        if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1471                return 1;
1472
1473        return 0;
1474}
1475
1476#ifndef NO_PTHREADS
1477
1478static pthread_mutex_t read_mutex;
1479#define read_lock()             pthread_mutex_lock(&read_mutex)
1480#define read_unlock()           pthread_mutex_unlock(&read_mutex)
1481
1482static pthread_mutex_t cache_mutex;
1483#define cache_lock()            pthread_mutex_lock(&cache_mutex)
1484#define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1485
1486static pthread_mutex_t progress_mutex;
1487#define progress_lock()         pthread_mutex_lock(&progress_mutex)
1488#define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1489
1490#else
1491
1492#define read_lock()             (void)0
1493#define read_unlock()           (void)0
1494#define cache_lock()            (void)0
1495#define cache_unlock()          (void)0
1496#define progress_lock()         (void)0
1497#define progress_unlock()       (void)0
1498
1499#endif
1500
1501static int try_delta(struct unpacked *trg, struct unpacked *src,
1502                     unsigned max_depth, unsigned long *mem_usage)
1503{
1504        struct object_entry *trg_entry = trg->entry;
1505        struct object_entry *src_entry = src->entry;
1506        unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1507        unsigned ref_depth;
1508        enum object_type type;
1509        void *delta_buf;
1510
1511        /* Don't bother doing diffs between different types */
1512        if (trg_entry->type != src_entry->type)
1513                return -1;
1514
1515        /*
1516         * We do not bother to try a delta that we discarded on an
1517         * earlier try, but only when reusing delta data.  Note that
1518         * src_entry that is marked as the preferred_base should always
1519         * be considered, as even if we produce a suboptimal delta against
1520         * it, we will still save the transfer cost, as we already know
1521         * the other side has it and we won't send src_entry at all.
1522         */
1523        if (reuse_delta && trg_entry->in_pack &&
1524            trg_entry->in_pack == src_entry->in_pack &&
1525            !src_entry->preferred_base &&
1526            trg_entry->in_pack_type != OBJ_REF_DELTA &&
1527            trg_entry->in_pack_type != OBJ_OFS_DELTA)
1528                return 0;
1529
1530        /* Let's not bust the allowed depth. */
1531        if (src->depth >= max_depth)
1532                return 0;
1533
1534        /* Now some size filtering heuristics. */
1535        trg_size = trg_entry->size;
1536        if (!trg_entry->delta) {
1537                max_size = trg_size/2 - 20;
1538                ref_depth = 1;
1539        } else {
1540                max_size = trg_entry->delta_size;
1541                ref_depth = trg->depth;
1542        }
1543        max_size = (uint64_t)max_size * (max_depth - src->depth) /
1544                                                (max_depth - ref_depth + 1);
1545        if (max_size == 0)
1546                return 0;
1547        src_size = src_entry->size;
1548        sizediff = src_size < trg_size ? trg_size - src_size : 0;
1549        if (sizediff >= max_size)
1550                return 0;
1551        if (trg_size < src_size / 32)
1552                return 0;
1553
1554        /* Load data if not already done */
1555        if (!trg->data) {
1556                read_lock();
1557                trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1558                read_unlock();
1559                if (!trg->data)
1560                        die("object %s cannot be read",
1561                            sha1_to_hex(trg_entry->idx.sha1));
1562                if (sz != trg_size)
1563                        die("object %s inconsistent object length (%lu vs %lu)",
1564                            sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1565                *mem_usage += sz;
1566        }
1567        if (!src->data) {
1568                read_lock();
1569                src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1570                read_unlock();
1571                if (!src->data) {
1572                        if (src_entry->preferred_base) {
1573                                static int warned = 0;
1574                                if (!warned++)
1575                                        warning("object %s cannot be read",
1576                                                sha1_to_hex(src_entry->idx.sha1));
1577                                /*
1578                                 * Those objects are not included in the
1579                                 * resulting pack.  Be resilient and ignore
1580                                 * them if they can't be read, in case the
1581                                 * pack could be created nevertheless.
1582                                 */
1583                                return 0;
1584                        }
1585                        die("object %s cannot be read",
1586                            sha1_to_hex(src_entry->idx.sha1));
1587                }
1588                if (sz != src_size)
1589                        die("object %s inconsistent object length (%lu vs %lu)",
1590                            sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1591                *mem_usage += sz;
1592        }
1593        if (!src->index) {
1594                src->index = create_delta_index(src->data, src_size);
1595                if (!src->index) {
1596                        static int warned = 0;
1597                        if (!warned++)
1598                                warning("suboptimal pack - out of memory");
1599                        return 0;
1600                }
1601                *mem_usage += sizeof_delta_index(src->index);
1602        }
1603
1604        delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1605        if (!delta_buf)
1606                return 0;
1607
1608        if (trg_entry->delta) {
1609                /* Prefer only shallower same-sized deltas. */
1610                if (delta_size == trg_entry->delta_size &&
1611                    src->depth + 1 >= trg->depth) {
1612                        free(delta_buf);
1613                        return 0;
1614                }
1615        }
1616
1617        /*
1618         * Handle memory allocation outside of the cache
1619         * accounting lock.  Compiler will optimize the strangeness
1620         * away when NO_PTHREADS is defined.
1621         */
1622        free(trg_entry->delta_data);
1623        cache_lock();
1624        if (trg_entry->delta_data) {
1625                delta_cache_size -= trg_entry->delta_size;
1626                trg_entry->delta_data = NULL;
1627        }
1628        if (delta_cacheable(src_size, trg_size, delta_size)) {
1629                delta_cache_size += delta_size;
1630                cache_unlock();
1631                trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1632        } else {
1633                cache_unlock();
1634                free(delta_buf);
1635        }
1636
1637        trg_entry->delta = src_entry;
1638        trg_entry->delta_size = delta_size;
1639        trg->depth = src->depth + 1;
1640
1641        return 1;
1642}
1643
1644static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1645{
1646        struct object_entry *child = me->delta_child;
1647        unsigned int m = n;
1648        while (child) {
1649                unsigned int c = check_delta_limit(child, n + 1);
1650                if (m < c)
1651                        m = c;
1652                child = child->delta_sibling;
1653        }
1654        return m;
1655}
1656
1657static unsigned long free_unpacked(struct unpacked *n)
1658{
1659        unsigned long freed_mem = sizeof_delta_index(n->index);
1660        free_delta_index(n->index);
1661        n->index = NULL;
1662        if (n->data) {
1663                freed_mem += n->entry->size;
1664                free(n->data);
1665                n->data = NULL;
1666        }
1667        n->entry = NULL;
1668        n->depth = 0;
1669        return freed_mem;
1670}
1671
1672static void find_deltas(struct object_entry **list, unsigned *list_size,
1673                        int window, int depth, unsigned *processed)
1674{
1675        uint32_t i, idx = 0, count = 0;
1676        struct unpacked *array;
1677        unsigned long mem_usage = 0;
1678
1679        array = xcalloc(window, sizeof(struct unpacked));
1680
1681        for (;;) {
1682                struct object_entry *entry;
1683                struct unpacked *n = array + idx;
1684                int j, max_depth, best_base = -1;
1685
1686                progress_lock();
1687                if (!*list_size) {
1688                        progress_unlock();
1689                        break;
1690                }
1691                entry = *list++;
1692                (*list_size)--;
1693                if (!entry->preferred_base) {
1694                        (*processed)++;
1695                        display_progress(progress_state, *processed);
1696                }
1697                progress_unlock();
1698
1699                mem_usage -= free_unpacked(n);
1700                n->entry = entry;
1701
1702                while (window_memory_limit &&
1703                       mem_usage > window_memory_limit &&
1704                       count > 1) {
1705                        uint32_t tail = (idx + window - count) % window;
1706                        mem_usage -= free_unpacked(array + tail);
1707                        count--;
1708                }
1709
1710                /* We do not compute delta to *create* objects we are not
1711                 * going to pack.
1712                 */
1713                if (entry->preferred_base)
1714                        goto next;
1715
1716                /*
1717                 * If the current object is at pack edge, take the depth the
1718                 * objects that depend on the current object into account
1719                 * otherwise they would become too deep.
1720                 */
1721                max_depth = depth;
1722                if (entry->delta_child) {
1723                        max_depth -= check_delta_limit(entry, 0);
1724                        if (max_depth <= 0)
1725                                goto next;
1726                }
1727
1728                j = window;
1729                while (--j > 0) {
1730                        int ret;
1731                        uint32_t other_idx = idx + j;
1732                        struct unpacked *m;
1733                        if (other_idx >= window)
1734                                other_idx -= window;
1735                        m = array + other_idx;
1736                        if (!m->entry)
1737                                break;
1738                        ret = try_delta(n, m, max_depth, &mem_usage);
1739                        if (ret < 0)
1740                                break;
1741                        else if (ret > 0)
1742                                best_base = other_idx;
1743                }
1744
1745                /*
1746                 * If we decided to cache the delta data, then it is best
1747                 * to compress it right away.  First because we have to do
1748                 * it anyway, and doing it here while we're threaded will
1749                 * save a lot of time in the non threaded write phase,
1750                 * as well as allow for caching more deltas within
1751                 * the same cache size limit.
1752                 * ...
1753                 * But only if not writing to stdout, since in that case
1754                 * the network is most likely throttling writes anyway,
1755                 * and therefore it is best to go to the write phase ASAP
1756                 * instead, as we can afford spending more time compressing
1757                 * between writes at that moment.
1758                 */
1759                if (entry->delta_data && !pack_to_stdout) {
1760                        entry->z_delta_size = do_compress(&entry->delta_data,
1761                                                          entry->delta_size);
1762                        cache_lock();
1763                        delta_cache_size -= entry->delta_size;
1764                        delta_cache_size += entry->z_delta_size;
1765                        cache_unlock();
1766                }
1767
1768                /* if we made n a delta, and if n is already at max
1769                 * depth, leaving it in the window is pointless.  we
1770                 * should evict it first.
1771                 */
1772                if (entry->delta && max_depth <= n->depth)
1773                        continue;
1774
1775                /*
1776                 * Move the best delta base up in the window, after the
1777                 * currently deltified object, to keep it longer.  It will
1778                 * be the first base object to be attempted next.
1779                 */
1780                if (entry->delta) {
1781                        struct unpacked swap = array[best_base];
1782                        int dist = (window + idx - best_base) % window;
1783                        int dst = best_base;
1784                        while (dist--) {
1785                                int src = (dst + 1) % window;
1786                                array[dst] = array[src];
1787                                dst = src;
1788                        }
1789                        array[dst] = swap;
1790                }
1791
1792                next:
1793                idx++;
1794                if (count + 1 < window)
1795                        count++;
1796                if (idx >= window)
1797                        idx = 0;
1798        }
1799
1800        for (i = 0; i < window; ++i) {
1801                free_delta_index(array[i].index);
1802                free(array[i].data);
1803        }
1804        free(array);
1805}
1806
1807#ifndef NO_PTHREADS
1808
1809static void try_to_free_from_threads(size_t size)
1810{
1811        read_lock();
1812        release_pack_memory(size, -1);
1813        read_unlock();
1814}
1815
1816static try_to_free_t old_try_to_free_routine;
1817
1818/*
1819 * The main thread waits on the condition that (at least) one of the workers
1820 * has stopped working (which is indicated in the .working member of
1821 * struct thread_params).
1822 * When a work thread has completed its work, it sets .working to 0 and
1823 * signals the main thread and waits on the condition that .data_ready
1824 * becomes 1.
1825 */
1826
1827struct thread_params {
1828        pthread_t thread;
1829        struct object_entry **list;
1830        unsigned list_size;
1831        unsigned remaining;
1832        int window;
1833        int depth;
1834        int working;
1835        int data_ready;
1836        pthread_mutex_t mutex;
1837        pthread_cond_t cond;
1838        unsigned *processed;
1839};
1840
1841static pthread_cond_t progress_cond;
1842
1843/*
1844 * Mutex and conditional variable can't be statically-initialized on Windows.
1845 */
1846static void init_threaded_search(void)
1847{
1848        init_recursive_mutex(&read_mutex);
1849        pthread_mutex_init(&cache_mutex, NULL);
1850        pthread_mutex_init(&progress_mutex, NULL);
1851        pthread_cond_init(&progress_cond, NULL);
1852        old_try_to_free_routine = set_try_to_free_routine(try_to_free_from_threads);
1853}
1854
1855static void cleanup_threaded_search(void)
1856{
1857        set_try_to_free_routine(old_try_to_free_routine);
1858        pthread_cond_destroy(&progress_cond);
1859        pthread_mutex_destroy(&read_mutex);
1860        pthread_mutex_destroy(&cache_mutex);
1861        pthread_mutex_destroy(&progress_mutex);
1862}
1863
1864static void *threaded_find_deltas(void *arg)
1865{
1866        struct thread_params *me = arg;
1867
1868        while (me->remaining) {
1869                find_deltas(me->list, &me->remaining,
1870                            me->window, me->depth, me->processed);
1871
1872                progress_lock();
1873                me->working = 0;
1874                pthread_cond_signal(&progress_cond);
1875                progress_unlock();
1876
1877                /*
1878                 * We must not set ->data_ready before we wait on the
1879                 * condition because the main thread may have set it to 1
1880                 * before we get here. In order to be sure that new
1881                 * work is available if we see 1 in ->data_ready, it
1882                 * was initialized to 0 before this thread was spawned
1883                 * and we reset it to 0 right away.
1884                 */
1885                pthread_mutex_lock(&me->mutex);
1886                while (!me->data_ready)
1887                        pthread_cond_wait(&me->cond, &me->mutex);
1888                me->data_ready = 0;
1889                pthread_mutex_unlock(&me->mutex);
1890        }
1891        /* leave ->working 1 so that this doesn't get more work assigned */
1892        return NULL;
1893}
1894
1895static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1896                           int window, int depth, unsigned *processed)
1897{
1898        struct thread_params *p;
1899        int i, ret, active_threads = 0;
1900
1901        init_threaded_search();
1902
1903        if (!delta_search_threads)      /* --threads=0 means autodetect */
1904                delta_search_threads = online_cpus();
1905        if (delta_search_threads <= 1) {
1906                find_deltas(list, &list_size, window, depth, processed);
1907                cleanup_threaded_search();
1908                return;
1909        }
1910        if (progress > pack_to_stdout)
1911                fprintf(stderr, "Delta compression using up to %d threads.\n",
1912                                delta_search_threads);
1913        p = xcalloc(delta_search_threads, sizeof(*p));
1914
1915        /* Partition the work amongst work threads. */
1916        for (i = 0; i < delta_search_threads; i++) {
1917                unsigned sub_size = list_size / (delta_search_threads - i);
1918
1919                /* don't use too small segments or no deltas will be found */
1920                if (sub_size < 2*window && i+1 < delta_search_threads)
1921                        sub_size = 0;
1922
1923                p[i].window = window;
1924                p[i].depth = depth;
1925                p[i].processed = processed;
1926                p[i].working = 1;
1927                p[i].data_ready = 0;
1928
1929                /* try to split chunks on "path" boundaries */
1930                while (sub_size && sub_size < list_size &&
1931                       list[sub_size]->hash &&
1932                       list[sub_size]->hash == list[sub_size-1]->hash)
1933                        sub_size++;
1934
1935                p[i].list = list;
1936                p[i].list_size = sub_size;
1937                p[i].remaining = sub_size;
1938
1939                list += sub_size;
1940                list_size -= sub_size;
1941        }
1942
1943        /* Start work threads. */
1944        for (i = 0; i < delta_search_threads; i++) {
1945                if (!p[i].list_size)
1946                        continue;
1947                pthread_mutex_init(&p[i].mutex, NULL);
1948                pthread_cond_init(&p[i].cond, NULL);
1949                ret = pthread_create(&p[i].thread, NULL,
1950                                     threaded_find_deltas, &p[i]);
1951                if (ret)
1952                        die("unable to create thread: %s", strerror(ret));
1953                active_threads++;
1954        }
1955
1956        /*
1957         * Now let's wait for work completion.  Each time a thread is done
1958         * with its work, we steal half of the remaining work from the
1959         * thread with the largest number of unprocessed objects and give
1960         * it to that newly idle thread.  This ensure good load balancing
1961         * until the remaining object list segments are simply too short
1962         * to be worth splitting anymore.
1963         */
1964        while (active_threads) {
1965                struct thread_params *target = NULL;
1966                struct thread_params *victim = NULL;
1967                unsigned sub_size = 0;
1968
1969                progress_lock();
1970                for (;;) {
1971                        for (i = 0; !target && i < delta_search_threads; i++)
1972                                if (!p[i].working)
1973                                        target = &p[i];
1974                        if (target)
1975                                break;
1976                        pthread_cond_wait(&progress_cond, &progress_mutex);
1977                }
1978
1979                for (i = 0; i < delta_search_threads; i++)
1980                        if (p[i].remaining > 2*window &&
1981                            (!victim || victim->remaining < p[i].remaining))
1982                                victim = &p[i];
1983                if (victim) {
1984                        sub_size = victim->remaining / 2;
1985                        list = victim->list + victim->list_size - sub_size;
1986                        while (sub_size && list[0]->hash &&
1987                               list[0]->hash == list[-1]->hash) {
1988                                list++;
1989                                sub_size--;
1990                        }
1991                        if (!sub_size) {
1992                                /*
1993                                 * It is possible for some "paths" to have
1994                                 * so many objects that no hash boundary
1995                                 * might be found.  Let's just steal the
1996                                 * exact half in that case.
1997                                 */
1998                                sub_size = victim->remaining / 2;
1999                                list -= sub_size;
2000                        }
2001                        target->list = list;
2002                        victim->list_size -= sub_size;
2003                        victim->remaining -= sub_size;
2004                }
2005                target->list_size = sub_size;
2006                target->remaining = sub_size;
2007                target->working = 1;
2008                progress_unlock();
2009
2010                pthread_mutex_lock(&target->mutex);
2011                target->data_ready = 1;
2012                pthread_cond_signal(&target->cond);
2013                pthread_mutex_unlock(&target->mutex);
2014
2015                if (!sub_size) {
2016                        pthread_join(target->thread, NULL);
2017                        pthread_cond_destroy(&target->cond);
2018                        pthread_mutex_destroy(&target->mutex);
2019                        active_threads--;
2020                }
2021        }
2022        cleanup_threaded_search();
2023        free(p);
2024}
2025
2026#else
2027#define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
2028#endif
2029
2030static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
2031{
2032        unsigned char peeled[20];
2033
2034        if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
2035            !peel_ref(path, peeled)        && /* peelable? */
2036            locate_object_entry(peeled))      /* object packed? */
2037                add_object_entry(sha1, OBJ_TAG, NULL, 0);
2038        return 0;
2039}
2040
2041static void prepare_pack(int window, int depth)
2042{
2043        struct object_entry **delta_list;
2044        uint32_t i, nr_deltas;
2045        unsigned n;
2046
2047        get_object_details();
2048
2049        /*
2050         * If we're locally repacking then we need to be doubly careful
2051         * from now on in order to make sure no stealth corruption gets
2052         * propagated to the new pack.  Clients receiving streamed packs
2053         * should validate everything they get anyway so no need to incur
2054         * the additional cost here in that case.
2055         */
2056        if (!pack_to_stdout)
2057                do_check_packed_object_crc = 1;
2058
2059        if (!nr_objects || !window || !depth)
2060                return;
2061
2062        delta_list = xmalloc(nr_objects * sizeof(*delta_list));
2063        nr_deltas = n = 0;
2064
2065        for (i = 0; i < nr_objects; i++) {
2066                struct object_entry *entry = objects + i;
2067
2068                if (entry->delta)
2069                        /* This happens if we decided to reuse existing
2070                         * delta from a pack.  "reuse_delta &&" is implied.
2071                         */
2072                        continue;
2073
2074                if (entry->size < 50)
2075                        continue;
2076
2077                if (entry->no_try_delta)
2078                        continue;
2079
2080                if (!entry->preferred_base) {
2081                        nr_deltas++;
2082                        if (entry->type < 0)
2083                                die("unable to get type of object %s",
2084                                    sha1_to_hex(entry->idx.sha1));
2085                } else {
2086                        if (entry->type < 0) {
2087                                /*
2088                                 * This object is not found, but we
2089                                 * don't have to include it anyway.
2090                                 */
2091                                continue;
2092                        }
2093                }
2094
2095                delta_list[n++] = entry;
2096        }
2097
2098        if (nr_deltas && n > 1) {
2099                unsigned nr_done = 0;
2100                if (progress)
2101                        progress_state = start_progress("Compressing objects",
2102                                                        nr_deltas);
2103                qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
2104                ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
2105                stop_progress(&progress_state);
2106                if (nr_done != nr_deltas)
2107                        die("inconsistency with delta count");
2108        }
2109        free(delta_list);
2110}
2111
2112static int git_pack_config(const char *k, const char *v, void *cb)
2113{
2114        if (!strcmp(k, "pack.window")) {
2115                window = git_config_int(k, v);
2116                return 0;
2117        }
2118        if (!strcmp(k, "pack.windowmemory")) {
2119                window_memory_limit = git_config_ulong(k, v);
2120                return 0;
2121        }
2122        if (!strcmp(k, "pack.depth")) {
2123                depth = git_config_int(k, v);
2124                return 0;
2125        }
2126        if (!strcmp(k, "pack.compression")) {
2127                int level = git_config_int(k, v);
2128                if (level == -1)
2129                        level = Z_DEFAULT_COMPRESSION;
2130                else if (level < 0 || level > Z_BEST_COMPRESSION)
2131                        die("bad pack compression level %d", level);
2132                pack_compression_level = level;
2133                pack_compression_seen = 1;
2134                return 0;
2135        }
2136        if (!strcmp(k, "pack.deltacachesize")) {
2137                max_delta_cache_size = git_config_int(k, v);
2138                return 0;
2139        }
2140        if (!strcmp(k, "pack.deltacachelimit")) {
2141                cache_max_small_delta_size = git_config_int(k, v);
2142                return 0;
2143        }
2144        if (!strcmp(k, "pack.threads")) {
2145                delta_search_threads = git_config_int(k, v);
2146                if (delta_search_threads < 0)
2147                        die("invalid number of threads specified (%d)",
2148                            delta_search_threads);
2149#ifdef NO_PTHREADS
2150                if (delta_search_threads != 1)
2151                        warning("no threads support, ignoring %s", k);
2152#endif
2153                return 0;
2154        }
2155        if (!strcmp(k, "pack.indexversion")) {
2156                pack_idx_opts.version = git_config_int(k, v);
2157                if (pack_idx_opts.version > 2)
2158                        die("bad pack.indexversion=%"PRIu32,
2159                            pack_idx_opts.version);
2160                return 0;
2161        }
2162        return git_default_config(k, v, cb);
2163}
2164
2165static void read_object_list_from_stdin(void)
2166{
2167        char line[40 + 1 + PATH_MAX + 2];
2168        unsigned char sha1[20];
2169
2170        for (;;) {
2171                if (!fgets(line, sizeof(line), stdin)) {
2172                        if (feof(stdin))
2173                                break;
2174                        if (!ferror(stdin))
2175                                die("fgets returned NULL, not EOF, not error!");
2176                        if (errno != EINTR)
2177                                die_errno("fgets");
2178                        clearerr(stdin);
2179                        continue;
2180                }
2181                if (line[0] == '-') {
2182                        if (get_sha1_hex(line+1, sha1))
2183                                die("expected edge sha1, got garbage:\n %s",
2184                                    line);
2185                        add_preferred_base(sha1);
2186                        continue;
2187                }
2188                if (get_sha1_hex(line, sha1))
2189                        die("expected sha1, got garbage:\n %s", line);
2190
2191                add_preferred_base_object(line+41);
2192                add_object_entry(sha1, 0, line+41, 0);
2193        }
2194}
2195
2196#define OBJECT_ADDED (1u<<20)
2197
2198static void show_commit(struct commit *commit, void *data)
2199{
2200        add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
2201        commit->object.flags |= OBJECT_ADDED;
2202}
2203
2204static void show_object(struct object *obj,
2205                        const struct name_path *path, const char *last,
2206                        void *data)
2207{
2208        char *name = path_name(path, last);
2209
2210        add_preferred_base_object(name);
2211        add_object_entry(obj->sha1, obj->type, name, 0);
2212        obj->flags |= OBJECT_ADDED;
2213
2214        /*
2215         * We will have generated the hash from the name,
2216         * but not saved a pointer to it - we can free it
2217         */
2218        free((char *)name);
2219}
2220
2221static void show_edge(struct commit *commit)
2222{
2223        add_preferred_base(commit->object.sha1);
2224}
2225
2226struct in_pack_object {
2227        off_t offset;
2228        struct object *object;
2229};
2230
2231struct in_pack {
2232        int alloc;
2233        int nr;
2234        struct in_pack_object *array;
2235};
2236
2237static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
2238{
2239        in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
2240        in_pack->array[in_pack->nr].object = object;
2241        in_pack->nr++;
2242}
2243
2244/*
2245 * Compare the objects in the offset order, in order to emulate the
2246 * "git rev-list --objects" output that produced the pack originally.
2247 */
2248static int ofscmp(const void *a_, const void *b_)
2249{
2250        struct in_pack_object *a = (struct in_pack_object *)a_;
2251        struct in_pack_object *b = (struct in_pack_object *)b_;
2252
2253        if (a->offset < b->offset)
2254                return -1;
2255        else if (a->offset > b->offset)
2256                return 1;
2257        else
2258                return hashcmp(a->object->sha1, b->object->sha1);
2259}
2260
2261static void add_objects_in_unpacked_packs(struct rev_info *revs)
2262{
2263        struct packed_git *p;
2264        struct in_pack in_pack;
2265        uint32_t i;
2266
2267        memset(&in_pack, 0, sizeof(in_pack));
2268
2269        for (p = packed_git; p; p = p->next) {
2270                const unsigned char *sha1;
2271                struct object *o;
2272
2273                if (!p->pack_local || p->pack_keep)
2274                        continue;
2275                if (open_pack_index(p))
2276                        die("cannot open pack index");
2277
2278                ALLOC_GROW(in_pack.array,
2279                           in_pack.nr + p->num_objects,
2280                           in_pack.alloc);
2281
2282                for (i = 0; i < p->num_objects; i++) {
2283                        sha1 = nth_packed_object_sha1(p, i);
2284                        o = lookup_unknown_object(sha1);
2285                        if (!(o->flags & OBJECT_ADDED))
2286                                mark_in_pack_object(o, p, &in_pack);
2287                        o->flags |= OBJECT_ADDED;
2288                }
2289        }
2290
2291        if (in_pack.nr) {
2292                qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
2293                      ofscmp);
2294                for (i = 0; i < in_pack.nr; i++) {
2295                        struct object *o = in_pack.array[i].object;
2296                        add_object_entry(o->sha1, o->type, "", 0);
2297                }
2298        }
2299        free(in_pack.array);
2300}
2301
2302static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2303{
2304        static struct packed_git *last_found = (void *)1;
2305        struct packed_git *p;
2306
2307        p = (last_found != (void *)1) ? last_found : packed_git;
2308
2309        while (p) {
2310                if ((!p->pack_local || p->pack_keep) &&
2311                        find_pack_entry_one(sha1, p)) {
2312                        last_found = p;
2313                        return 1;
2314                }
2315                if (p == last_found)
2316                        p = packed_git;
2317                else
2318                        p = p->next;
2319                if (p == last_found)
2320                        p = p->next;
2321        }
2322        return 0;
2323}
2324
2325static void loosen_unused_packed_objects(struct rev_info *revs)
2326{
2327        struct packed_git *p;
2328        uint32_t i;
2329        const unsigned char *sha1;
2330
2331        for (p = packed_git; p; p = p->next) {
2332                if (!p->pack_local || p->pack_keep)
2333                        continue;
2334
2335                if (unpack_unreachable_expiration &&
2336                    p->mtime < unpack_unreachable_expiration)
2337                        continue;
2338
2339                if (open_pack_index(p))
2340                        die("cannot open pack index");
2341
2342                for (i = 0; i < p->num_objects; i++) {
2343                        sha1 = nth_packed_object_sha1(p, i);
2344                        if (!locate_object_entry(sha1) &&
2345                                !has_sha1_pack_kept_or_nonlocal(sha1))
2346                                if (force_object_loose(sha1, p->mtime))
2347                                        die("unable to force loose object");
2348                }
2349        }
2350}
2351
2352static void get_object_list(int ac, const char **av)
2353{
2354        struct rev_info revs;
2355        char line[1000];
2356        int flags = 0;
2357
2358        init_revisions(&revs, NULL);
2359        save_commit_buffer = 0;
2360        setup_revisions(ac, av, &revs, NULL);
2361
2362        while (fgets(line, sizeof(line), stdin) != NULL) {
2363                int len = strlen(line);
2364                if (len && line[len - 1] == '\n')
2365                        line[--len] = 0;
2366                if (!len)
2367                        break;
2368                if (*line == '-') {
2369                        if (!strcmp(line, "--not")) {
2370                                flags ^= UNINTERESTING;
2371                                continue;
2372                        }
2373                        die("not a rev '%s'", line);
2374                }
2375                if (handle_revision_arg(line, &revs, flags, REVARG_CANNOT_BE_FILENAME))
2376                        die("bad revision '%s'", line);
2377        }
2378
2379        if (prepare_revision_walk(&revs))
2380                die("revision walk setup failed");
2381        mark_edges_uninteresting(revs.commits, &revs, show_edge);
2382        traverse_commit_list(&revs, show_commit, show_object, NULL);
2383
2384        if (keep_unreachable)
2385                add_objects_in_unpacked_packs(&revs);
2386        if (unpack_unreachable)
2387                loosen_unused_packed_objects(&revs);
2388}
2389
2390static int option_parse_index_version(const struct option *opt,
2391                                      const char *arg, int unset)
2392{
2393        char *c;
2394        const char *val = arg;
2395        pack_idx_opts.version = strtoul(val, &c, 10);
2396        if (pack_idx_opts.version > 2)
2397                die(_("unsupported index version %s"), val);
2398        if (*c == ',' && c[1])
2399                pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
2400        if (*c || pack_idx_opts.off32_limit & 0x80000000)
2401                die(_("bad index version '%s'"), val);
2402        return 0;
2403}
2404
2405static int option_parse_unpack_unreachable(const struct option *opt,
2406                                           const char *arg, int unset)
2407{
2408        if (unset) {
2409                unpack_unreachable = 0;
2410                unpack_unreachable_expiration = 0;
2411        }
2412        else {
2413                unpack_unreachable = 1;
2414                if (arg)
2415                        unpack_unreachable_expiration = approxidate(arg);
2416        }
2417        return 0;
2418}
2419
2420static int option_parse_ulong(const struct option *opt,
2421                              const char *arg, int unset)
2422{
2423        if (unset)
2424                die(_("option %s does not accept negative form"),
2425                    opt->long_name);
2426
2427        if (!git_parse_ulong(arg, opt->value))
2428                die(_("unable to parse value '%s' for option %s"),
2429                    arg, opt->long_name);
2430        return 0;
2431}
2432
2433#define OPT_ULONG(s, l, v, h) \
2434        { OPTION_CALLBACK, (s), (l), (v), "n", (h),     \
2435          PARSE_OPT_NONEG, option_parse_ulong }
2436
2437int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2438{
2439        int use_internal_rev_list = 0;
2440        int thin = 0;
2441        int all_progress_implied = 0;
2442        const char *rp_av[6];
2443        int rp_ac = 0;
2444        int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
2445        struct option pack_objects_options[] = {
2446                OPT_SET_INT('q', "quiet", &progress,
2447                            N_("do not show progress meter"), 0),
2448                OPT_SET_INT(0, "progress", &progress,
2449                            N_("show progress meter"), 1),
2450                OPT_SET_INT(0, "all-progress", &progress,
2451                            N_("show progress meter during object writing phase"), 2),
2452                OPT_BOOL(0, "all-progress-implied",
2453                         &all_progress_implied,
2454                         N_("similar to --all-progress when progress meter is shown")),
2455                { OPTION_CALLBACK, 0, "index-version", NULL, N_("version[,offset]"),
2456                  N_("write the pack index file in the specified idx format version"),
2457                  0, option_parse_index_version },
2458                OPT_ULONG(0, "max-pack-size", &pack_size_limit,
2459                          N_("maximum size of each output pack file")),
2460                OPT_BOOL(0, "local", &local,
2461                         N_("ignore borrowed objects from alternate object store")),
2462                OPT_BOOL(0, "incremental", &incremental,
2463                         N_("ignore packed objects")),
2464                OPT_INTEGER(0, "window", &window,
2465                            N_("limit pack window by objects")),
2466                OPT_ULONG(0, "window-memory", &window_memory_limit,
2467                          N_("limit pack window by memory in addition to object limit")),
2468                OPT_INTEGER(0, "depth", &depth,
2469                            N_("maximum length of delta chain allowed in the resulting pack")),
2470                OPT_BOOL(0, "reuse-delta", &reuse_delta,
2471                         N_("reuse existing deltas")),
2472                OPT_BOOL(0, "reuse-object", &reuse_object,
2473                         N_("reuse existing objects")),
2474                OPT_BOOL(0, "delta-base-offset", &allow_ofs_delta,
2475                         N_("use OFS_DELTA objects")),
2476                OPT_INTEGER(0, "threads", &delta_search_threads,
2477                            N_("use threads when searching for best delta matches")),
2478                OPT_BOOL(0, "non-empty", &non_empty,
2479                         N_("do not create an empty pack output")),
2480                OPT_BOOL(0, "revs", &use_internal_rev_list,
2481                         N_("read revision arguments from standard input")),
2482                { OPTION_SET_INT, 0, "unpacked", &rev_list_unpacked, NULL,
2483                  N_("limit the objects to those that are not yet packed"),
2484                  PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2485                { OPTION_SET_INT, 0, "all", &rev_list_all, NULL,
2486                  N_("include objects reachable from any reference"),
2487                  PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2488                { OPTION_SET_INT, 0, "reflog", &rev_list_reflog, NULL,
2489                  N_("include objects referred by reflog entries"),
2490                  PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2491                OPT_BOOL(0, "stdout", &pack_to_stdout,
2492                         N_("output pack to stdout")),
2493                OPT_BOOL(0, "include-tag", &include_tag,
2494                         N_("include tag objects that refer to objects to be packed")),
2495                OPT_BOOL(0, "keep-unreachable", &keep_unreachable,
2496                         N_("keep unreachable objects")),
2497                { OPTION_CALLBACK, 0, "unpack-unreachable", NULL, N_("time"),
2498                  N_("unpack unreachable objects newer than <time>"),
2499                  PARSE_OPT_OPTARG, option_parse_unpack_unreachable },
2500                OPT_BOOL(0, "thin", &thin,
2501                         N_("create thin packs")),
2502                OPT_BOOL(0, "honor-pack-keep", &ignore_packed_keep,
2503                         N_("ignore packs that have companion .keep file")),
2504                OPT_INTEGER(0, "compression", &pack_compression_level,
2505                            N_("pack compression level")),
2506                OPT_SET_INT(0, "keep-true-parents", &grafts_replace_parents,
2507                            N_("do not hide commits by grafts"), 0),
2508                OPT_END(),
2509        };
2510
2511        read_replace_refs = 0;
2512
2513        reset_pack_idx_option(&pack_idx_opts);
2514        git_config(git_pack_config, NULL);
2515        if (!pack_compression_seen && core_compression_seen)
2516                pack_compression_level = core_compression_level;
2517
2518        progress = isatty(2);
2519        argc = parse_options(argc, argv, prefix, pack_objects_options,
2520                             pack_usage, 0);
2521
2522        if (argc) {
2523                base_name = argv[0];
2524                argc--;
2525        }
2526        if (pack_to_stdout != !base_name || argc)
2527                usage_with_options(pack_usage, pack_objects_options);
2528
2529        rp_av[rp_ac++] = "pack-objects";
2530        if (thin) {
2531                use_internal_rev_list = 1;
2532                rp_av[rp_ac++] = "--objects-edge";
2533        } else
2534                rp_av[rp_ac++] = "--objects";
2535
2536        if (rev_list_all) {
2537                use_internal_rev_list = 1;
2538                rp_av[rp_ac++] = "--all";
2539        }
2540        if (rev_list_reflog) {
2541                use_internal_rev_list = 1;
2542                rp_av[rp_ac++] = "--reflog";
2543        }
2544        if (rev_list_unpacked) {
2545                use_internal_rev_list = 1;
2546                rp_av[rp_ac++] = "--unpacked";
2547        }
2548
2549        if (!reuse_object)
2550                reuse_delta = 0;
2551        if (pack_compression_level == -1)
2552                pack_compression_level = Z_DEFAULT_COMPRESSION;
2553        else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
2554                die("bad pack compression level %d", pack_compression_level);
2555#ifdef NO_PTHREADS
2556        if (delta_search_threads != 1)
2557                warning("no threads support, ignoring --threads");
2558#endif
2559        if (!pack_to_stdout && !pack_size_limit)
2560                pack_size_limit = pack_size_limit_cfg;
2561        if (pack_to_stdout && pack_size_limit)
2562                die("--max-pack-size cannot be used to build a pack for transfer.");
2563        if (pack_size_limit && pack_size_limit < 1024*1024) {
2564                warning("minimum pack size limit is 1 MiB");
2565                pack_size_limit = 1024*1024;
2566        }
2567
2568        if (!pack_to_stdout && thin)
2569                die("--thin cannot be used to build an indexable pack.");
2570
2571        if (keep_unreachable && unpack_unreachable)
2572                die("--keep-unreachable and --unpack-unreachable are incompatible.");
2573
2574        if (progress && all_progress_implied)
2575                progress = 2;
2576
2577        prepare_packed_git();
2578
2579        if (progress)
2580                progress_state = start_progress("Counting objects", 0);
2581        if (!use_internal_rev_list)
2582                read_object_list_from_stdin();
2583        else {
2584                rp_av[rp_ac] = NULL;
2585                get_object_list(rp_ac, rp_av);
2586        }
2587        cleanup_preferred_base();
2588        if (include_tag && nr_result)
2589                for_each_ref(add_ref_tag, NULL);
2590        stop_progress(&progress_state);
2591
2592        if (non_empty && !nr_result)
2593                return 0;
2594        if (nr_result)
2595                prepare_pack(window, depth);
2596        write_pack_file();
2597        if (progress)
2598                fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2599                        " reused %"PRIu32" (delta %"PRIu32")\n",
2600                        written, written_delta, reused, reused_delta);
2601        return 0;
2602}