builtin-pack-objects.con commit Improve error output of git-rebase (9b752a6)
   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
  20#ifdef THREADED_DELTA_SEARCH
  21#include "thread-utils.h"
  22#include <pthread.h>
  23#endif
  24
  25static const char pack_usage[] = "\
  26git-pack-objects [{ -q | --progress | --all-progress }] \n\
  27        [--max-pack-size=N] [--local] [--incremental] \n\
  28        [--window=N] [--window-memory=N] [--depth=N] \n\
  29        [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
  30        [--threads=N] [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
  31        [--stdout | base-name] [--include-tag] \n\
  32        [--keep-unreachable | --unpack-unreachable] \n\
  33        [<ref-list | <object-list]";
  34
  35struct object_entry {
  36        struct pack_idx_entry idx;
  37        unsigned long size;     /* uncompressed size */
  38        struct packed_git *in_pack;     /* already in pack */
  39        off_t in_pack_offset;
  40        struct object_entry *delta;     /* delta base object */
  41        struct object_entry *delta_child; /* deltified objects who bases me */
  42        struct object_entry *delta_sibling; /* other deltified objects who
  43                                             * uses the same base as me
  44                                             */
  45        void *delta_data;       /* cached delta (uncompressed) */
  46        unsigned long delta_size;       /* delta data size (uncompressed) */
  47        unsigned long z_delta_size;     /* delta data size (compressed) */
  48        unsigned int hash;      /* name hint hash */
  49        enum object_type type;
  50        enum object_type in_pack_type;  /* could be delta */
  51        unsigned char in_pack_header_size;
  52        unsigned char preferred_base; /* we do not pack this, but is available
  53                                       * to be used as the base object to delta
  54                                       * objects against.
  55                                       */
  56        unsigned char no_try_delta;
  57};
  58
  59/*
  60 * Objects we are going to pack are collected in objects array (dynamically
  61 * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  62 * in the order we see -- typically rev-list --objects order that gives us
  63 * nice "minimum seek" order.
  64 */
  65static struct object_entry *objects;
  66static struct pack_idx_entry **written_list;
  67static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
  68
  69static int non_empty;
  70static int reuse_delta = 1, reuse_object = 1;
  71static int keep_unreachable, unpack_unreachable, include_tag;
  72static int local;
  73static int incremental;
  74static int allow_ofs_delta;
  75static const char *base_name;
  76static int progress = 1;
  77static int window = 10;
  78static uint32_t pack_size_limit, pack_size_limit_cfg;
  79static int depth = 50;
  80static int delta_search_threads = 1;
  81static int pack_to_stdout;
  82static int num_preferred_base;
  83static struct progress *progress_state;
  84static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  85static int pack_compression_seen;
  86
  87static unsigned long delta_cache_size = 0;
  88static unsigned long max_delta_cache_size = 0;
  89static unsigned long cache_max_small_delta_size = 1000;
  90
  91static unsigned long window_memory_limit = 0;
  92
  93/*
  94 * The object names in objects array are hashed with this hashtable,
  95 * to help looking up the entry by object name.
  96 * This hashtable is built after all the objects are seen.
  97 */
  98static int *object_ix;
  99static int object_ix_hashsz;
 100
 101/*
 102 * stats
 103 */
 104static uint32_t written, written_delta;
 105static uint32_t reused, reused_delta;
 106
 107
 108static void *get_delta(struct object_entry *entry)
 109{
 110        unsigned long size, base_size, delta_size;
 111        void *buf, *base_buf, *delta_buf;
 112        enum object_type type;
 113
 114        buf = read_sha1_file(entry->idx.sha1, &type, &size);
 115        if (!buf)
 116                die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 117        base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
 118        if (!base_buf)
 119                die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 120        delta_buf = diff_delta(base_buf, base_size,
 121                               buf, size, &delta_size, 0);
 122        if (!delta_buf || delta_size != entry->delta_size)
 123                die("delta size changed");
 124        free(buf);
 125        free(base_buf);
 126        return delta_buf;
 127}
 128
 129static unsigned long do_compress(void **pptr, unsigned long size)
 130{
 131        z_stream stream;
 132        void *in, *out;
 133        unsigned long maxsize;
 134
 135        memset(&stream, 0, sizeof(stream));
 136        deflateInit(&stream, pack_compression_level);
 137        maxsize = deflateBound(&stream, size);
 138
 139        in = *pptr;
 140        out = xmalloc(maxsize);
 141        *pptr = out;
 142
 143        stream.next_in = in;
 144        stream.avail_in = size;
 145        stream.next_out = out;
 146        stream.avail_out = maxsize;
 147        while (deflate(&stream, Z_FINISH) == Z_OK)
 148                ; /* nothing */
 149        deflateEnd(&stream);
 150
 151        free(in);
 152        return stream.total_out;
 153}
 154
 155/*
 156 * The per-object header is a pretty dense thing, which is
 157 *  - first byte: low four bits are "size", then three bits of "type",
 158 *    and the high bit is "size continues".
 159 *  - each byte afterwards: low seven bits are size continuation,
 160 *    with the high bit being "size continues"
 161 */
 162static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 163{
 164        int n = 1;
 165        unsigned char c;
 166
 167        if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 168                die("bad type %d", type);
 169
 170        c = (type << 4) | (size & 15);
 171        size >>= 4;
 172        while (size) {
 173                *hdr++ = c | 0x80;
 174                c = size & 0x7f;
 175                size >>= 7;
 176                n++;
 177        }
 178        *hdr = c;
 179        return n;
 180}
 181
 182/*
 183 * we are going to reuse the existing object data as is.  make
 184 * sure it is not corrupt.
 185 */
 186static int check_pack_inflate(struct packed_git *p,
 187                struct pack_window **w_curs,
 188                off_t offset,
 189                off_t len,
 190                unsigned long expect)
 191{
 192        z_stream stream;
 193        unsigned char fakebuf[4096], *in;
 194        int st;
 195
 196        memset(&stream, 0, sizeof(stream));
 197        inflateInit(&stream);
 198        do {
 199                in = use_pack(p, w_curs, offset, &stream.avail_in);
 200                stream.next_in = in;
 201                stream.next_out = fakebuf;
 202                stream.avail_out = sizeof(fakebuf);
 203                st = inflate(&stream, Z_FINISH);
 204                offset += stream.next_in - in;
 205        } while (st == Z_OK || st == Z_BUF_ERROR);
 206        inflateEnd(&stream);
 207        return (st == Z_STREAM_END &&
 208                stream.total_out == expect &&
 209                stream.total_in == len) ? 0 : -1;
 210}
 211
 212static void copy_pack_data(struct sha1file *f,
 213                struct packed_git *p,
 214                struct pack_window **w_curs,
 215                off_t offset,
 216                off_t len)
 217{
 218        unsigned char *in;
 219        unsigned int avail;
 220
 221        while (len) {
 222                in = use_pack(p, w_curs, offset, &avail);
 223                if (avail > len)
 224                        avail = (unsigned int)len;
 225                sha1write(f, in, avail);
 226                offset += avail;
 227                len -= avail;
 228        }
 229}
 230
 231static unsigned long write_object(struct sha1file *f,
 232                                  struct object_entry *entry,
 233                                  off_t write_offset)
 234{
 235        unsigned long size, limit, datalen;
 236        void *buf;
 237        unsigned char header[10], dheader[10];
 238        unsigned hdrlen;
 239        enum object_type type;
 240        int usable_delta, to_reuse;
 241
 242        if (!pack_to_stdout)
 243                crc32_begin(f);
 244
 245        type = entry->type;
 246
 247        /* write limit if limited packsize and not first object */
 248        limit = pack_size_limit && nr_written ?
 249                        pack_size_limit - write_offset : 0;
 250
 251        if (!entry->delta)
 252                usable_delta = 0;       /* no delta */
 253        else if (!pack_size_limit)
 254               usable_delta = 1;        /* unlimited packfile */
 255        else if (entry->delta->idx.offset == (off_t)-1)
 256                usable_delta = 0;       /* base was written to another pack */
 257        else if (entry->delta->idx.offset)
 258                usable_delta = 1;       /* base already exists in this pack */
 259        else
 260                usable_delta = 0;       /* base could end up in another pack */
 261
 262        if (!reuse_object)
 263                to_reuse = 0;   /* explicit */
 264        else if (!entry->in_pack)
 265                to_reuse = 0;   /* can't reuse what we don't have */
 266        else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
 267                                /* check_object() decided it for us ... */
 268                to_reuse = usable_delta;
 269                                /* ... but pack split may override that */
 270        else if (type != entry->in_pack_type)
 271                to_reuse = 0;   /* pack has delta which is unusable */
 272        else if (entry->delta)
 273                to_reuse = 0;   /* we want to pack afresh */
 274        else
 275                to_reuse = 1;   /* we have it in-pack undeltified,
 276                                 * and we do not need to deltify it.
 277                                 */
 278
 279        if (!to_reuse) {
 280                if (!usable_delta) {
 281                        buf = read_sha1_file(entry->idx.sha1, &type, &size);
 282                        if (!buf)
 283                                die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 284                        /*
 285                         * make sure no cached delta data remains from a
 286                         * previous attempt before a pack split occured.
 287                         */
 288                        free(entry->delta_data);
 289                        entry->delta_data = NULL;
 290                        entry->z_delta_size = 0;
 291                } else if (entry->delta_data) {
 292                        size = entry->delta_size;
 293                        buf = entry->delta_data;
 294                        entry->delta_data = NULL;
 295                        type = (allow_ofs_delta && entry->delta->idx.offset) ?
 296                                OBJ_OFS_DELTA : OBJ_REF_DELTA;
 297                } else {
 298                        buf = get_delta(entry);
 299                        size = entry->delta_size;
 300                        type = (allow_ofs_delta && entry->delta->idx.offset) ?
 301                                OBJ_OFS_DELTA : OBJ_REF_DELTA;
 302                }
 303
 304                if (entry->z_delta_size)
 305                        datalen = entry->z_delta_size;
 306                else
 307                        datalen = do_compress(&buf, size);
 308
 309                /*
 310                 * The object header is a byte of 'type' followed by zero or
 311                 * more bytes of length.
 312                 */
 313                hdrlen = encode_header(type, size, header);
 314
 315                if (type == OBJ_OFS_DELTA) {
 316                        /*
 317                         * Deltas with relative base contain an additional
 318                         * encoding of the relative offset for the delta
 319                         * base from this object's position in the pack.
 320                         */
 321                        off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 322                        unsigned pos = sizeof(dheader) - 1;
 323                        dheader[pos] = ofs & 127;
 324                        while (ofs >>= 7)
 325                                dheader[--pos] = 128 | (--ofs & 127);
 326                        if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 327                                free(buf);
 328                                return 0;
 329                        }
 330                        sha1write(f, header, hdrlen);
 331                        sha1write(f, dheader + pos, sizeof(dheader) - pos);
 332                        hdrlen += sizeof(dheader) - pos;
 333                } else if (type == OBJ_REF_DELTA) {
 334                        /*
 335                         * Deltas with a base reference contain
 336                         * an additional 20 bytes for the base sha1.
 337                         */
 338                        if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 339                                free(buf);
 340                                return 0;
 341                        }
 342                        sha1write(f, header, hdrlen);
 343                        sha1write(f, entry->delta->idx.sha1, 20);
 344                        hdrlen += 20;
 345                } else {
 346                        if (limit && hdrlen + datalen + 20 >= limit) {
 347                                free(buf);
 348                                return 0;
 349                        }
 350                        sha1write(f, header, hdrlen);
 351                }
 352                sha1write(f, buf, datalen);
 353                free(buf);
 354        }
 355        else {
 356                struct packed_git *p = entry->in_pack;
 357                struct pack_window *w_curs = NULL;
 358                struct revindex_entry *revidx;
 359                off_t offset;
 360
 361                if (entry->delta) {
 362                        type = (allow_ofs_delta && entry->delta->idx.offset) ?
 363                                OBJ_OFS_DELTA : OBJ_REF_DELTA;
 364                        reused_delta++;
 365                }
 366                hdrlen = encode_header(type, entry->size, header);
 367                offset = entry->in_pack_offset;
 368                revidx = find_pack_revindex(p, offset);
 369                datalen = revidx[1].offset - offset;
 370                if (!pack_to_stdout && p->index_version > 1 &&
 371                    check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
 372                        die("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 373                offset += entry->in_pack_header_size;
 374                datalen -= entry->in_pack_header_size;
 375                if (type == OBJ_OFS_DELTA) {
 376                        off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 377                        unsigned pos = sizeof(dheader) - 1;
 378                        dheader[pos] = ofs & 127;
 379                        while (ofs >>= 7)
 380                                dheader[--pos] = 128 | (--ofs & 127);
 381                        if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit)
 382                                return 0;
 383                        sha1write(f, header, hdrlen);
 384                        sha1write(f, dheader + pos, sizeof(dheader) - pos);
 385                        hdrlen += sizeof(dheader) - pos;
 386                } else if (type == OBJ_REF_DELTA) {
 387                        if (limit && hdrlen + 20 + datalen + 20 >= limit)
 388                                return 0;
 389                        sha1write(f, header, hdrlen);
 390                        sha1write(f, entry->delta->idx.sha1, 20);
 391                        hdrlen += 20;
 392                } else {
 393                        if (limit && hdrlen + datalen + 20 >= limit)
 394                                return 0;
 395                        sha1write(f, header, hdrlen);
 396                }
 397
 398                if (!pack_to_stdout && p->index_version == 1 &&
 399                    check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
 400                        die("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 401                copy_pack_data(f, p, &w_curs, offset, datalen);
 402                unuse_pack(&w_curs);
 403                reused++;
 404        }
 405        if (usable_delta)
 406                written_delta++;
 407        written++;
 408        if (!pack_to_stdout)
 409                entry->idx.crc32 = crc32_end(f);
 410        return hdrlen + datalen;
 411}
 412
 413static off_t write_one(struct sha1file *f,
 414                               struct object_entry *e,
 415                               off_t offset)
 416{
 417        unsigned long size;
 418
 419        /* offset is non zero if object is written already. */
 420        if (e->idx.offset || e->preferred_base)
 421                return offset;
 422
 423        /* if we are deltified, write out base object first. */
 424        if (e->delta) {
 425                offset = write_one(f, e->delta, offset);
 426                if (!offset)
 427                        return 0;
 428        }
 429
 430        e->idx.offset = offset;
 431        size = write_object(f, e, offset);
 432        if (!size) {
 433                e->idx.offset = 0;
 434                return 0;
 435        }
 436        written_list[nr_written++] = &e->idx;
 437
 438        /* make sure off_t is sufficiently large not to wrap */
 439        if (offset > offset + size)
 440                die("pack too large for current definition of off_t");
 441        return offset + size;
 442}
 443
 444/* forward declaration for write_pack_file */
 445static int adjust_perm(const char *path, mode_t mode);
 446
 447static void write_pack_file(void)
 448{
 449        uint32_t i = 0, j;
 450        struct sha1file *f;
 451        off_t offset, offset_one, last_obj_offset = 0;
 452        struct pack_header hdr;
 453        uint32_t nr_remaining = nr_result;
 454        time_t last_mtime = 0;
 455
 456        if (progress > pack_to_stdout)
 457                progress_state = start_progress("Writing objects", nr_result);
 458        written_list = xmalloc(nr_objects * sizeof(*written_list));
 459
 460        do {
 461                unsigned char sha1[20];
 462                char *pack_tmp_name = NULL;
 463
 464                if (pack_to_stdout) {
 465                        f = sha1fd_throughput(1, "<stdout>", progress_state);
 466                } else {
 467                        char tmpname[PATH_MAX];
 468                        int fd;
 469                        snprintf(tmpname, sizeof(tmpname),
 470                                 "%s/tmp_pack_XXXXXX", get_object_directory());
 471                        fd = xmkstemp(tmpname);
 472                        pack_tmp_name = xstrdup(tmpname);
 473                        f = sha1fd(fd, pack_tmp_name);
 474                }
 475
 476                hdr.hdr_signature = htonl(PACK_SIGNATURE);
 477                hdr.hdr_version = htonl(PACK_VERSION);
 478                hdr.hdr_entries = htonl(nr_remaining);
 479                sha1write(f, &hdr, sizeof(hdr));
 480                offset = sizeof(hdr);
 481                nr_written = 0;
 482                for (; i < nr_objects; i++) {
 483                        last_obj_offset = offset;
 484                        offset_one = write_one(f, objects + i, offset);
 485                        if (!offset_one)
 486                                break;
 487                        offset = offset_one;
 488                        display_progress(progress_state, written);
 489                }
 490
 491                /*
 492                 * Did we write the wrong # entries in the header?
 493                 * If so, rewrite it like in fast-import
 494                 */
 495                if (pack_to_stdout) {
 496                        sha1close(f, sha1, CSUM_CLOSE);
 497                } else if (nr_written == nr_remaining) {
 498                        sha1close(f, sha1, CSUM_FSYNC);
 499                } else {
 500                        int fd = sha1close(f, NULL, 0);
 501                        fixup_pack_header_footer(fd, sha1, pack_tmp_name, nr_written);
 502                        fsync_or_die(fd, pack_tmp_name);
 503                        close(fd);
 504                }
 505
 506                if (!pack_to_stdout) {
 507                        mode_t mode = umask(0);
 508                        struct stat st;
 509                        char *idx_tmp_name, tmpname[PATH_MAX];
 510
 511                        umask(mode);
 512                        mode = 0444 & ~mode;
 513
 514                        idx_tmp_name = write_idx_file(NULL, written_list,
 515                                                      nr_written, sha1);
 516
 517                        snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 518                                 base_name, sha1_to_hex(sha1));
 519                        if (adjust_perm(pack_tmp_name, mode))
 520                                die("unable to make temporary pack file readable: %s",
 521                                    strerror(errno));
 522                        if (rename(pack_tmp_name, tmpname))
 523                                die("unable to rename temporary pack file: %s",
 524                                    strerror(errno));
 525
 526                        /*
 527                         * Packs are runtime accessed in their mtime
 528                         * order since newer packs are more likely to contain
 529                         * younger objects.  So if we are creating multiple
 530                         * packs then we should modify the mtime of later ones
 531                         * to preserve this property.
 532                         */
 533                        if (stat(tmpname, &st) < 0) {
 534                                warning("failed to stat %s: %s",
 535                                        tmpname, strerror(errno));
 536                        } else if (!last_mtime) {
 537                                last_mtime = st.st_mtime;
 538                        } else {
 539                                struct utimbuf utb;
 540                                utb.actime = st.st_atime;
 541                                utb.modtime = --last_mtime;
 542                                if (utime(tmpname, &utb) < 0)
 543                                        warning("failed utime() on %s: %s",
 544                                                tmpname, strerror(errno));
 545                        }
 546
 547                        snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 548                                 base_name, sha1_to_hex(sha1));
 549                        if (adjust_perm(idx_tmp_name, mode))
 550                                die("unable to make temporary index file readable: %s",
 551                                    strerror(errno));
 552                        if (rename(idx_tmp_name, tmpname))
 553                                die("unable to rename temporary index file: %s",
 554                                    strerror(errno));
 555
 556                        free(idx_tmp_name);
 557                        free(pack_tmp_name);
 558                        puts(sha1_to_hex(sha1));
 559                }
 560
 561                /* mark written objects as written to previous pack */
 562                for (j = 0; j < nr_written; j++) {
 563                        written_list[j]->offset = (off_t)-1;
 564                }
 565                nr_remaining -= nr_written;
 566        } while (nr_remaining && i < nr_objects);
 567
 568        free(written_list);
 569        stop_progress(&progress_state);
 570        if (written != nr_result)
 571                die("wrote %"PRIu32" objects while expecting %"PRIu32,
 572                        written, nr_result);
 573        /*
 574         * We have scanned through [0 ... i).  Since we have written
 575         * the correct number of objects,  the remaining [i ... nr_objects)
 576         * items must be either already written (due to out-of-order delta base)
 577         * or a preferred base.  Count those which are neither and complain if any.
 578         */
 579        for (j = 0; i < nr_objects; i++) {
 580                struct object_entry *e = objects + i;
 581                j += !e->idx.offset && !e->preferred_base;
 582        }
 583        if (j)
 584                die("wrote %"PRIu32" objects as expected but %"PRIu32
 585                        " unwritten", written, j);
 586}
 587
 588static int locate_object_entry_hash(const unsigned char *sha1)
 589{
 590        int i;
 591        unsigned int ui;
 592        memcpy(&ui, sha1, sizeof(unsigned int));
 593        i = ui % object_ix_hashsz;
 594        while (0 < object_ix[i]) {
 595                if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 596                        return i;
 597                if (++i == object_ix_hashsz)
 598                        i = 0;
 599        }
 600        return -1 - i;
 601}
 602
 603static struct object_entry *locate_object_entry(const unsigned char *sha1)
 604{
 605        int i;
 606
 607        if (!object_ix_hashsz)
 608                return NULL;
 609
 610        i = locate_object_entry_hash(sha1);
 611        if (0 <= i)
 612                return &objects[object_ix[i]-1];
 613        return NULL;
 614}
 615
 616static void rehash_objects(void)
 617{
 618        uint32_t i;
 619        struct object_entry *oe;
 620
 621        object_ix_hashsz = nr_objects * 3;
 622        if (object_ix_hashsz < 1024)
 623                object_ix_hashsz = 1024;
 624        object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 625        memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 626        for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 627                int ix = locate_object_entry_hash(oe->idx.sha1);
 628                if (0 <= ix)
 629                        continue;
 630                ix = -1 - ix;
 631                object_ix[ix] = i + 1;
 632        }
 633}
 634
 635static unsigned name_hash(const char *name)
 636{
 637        unsigned char c;
 638        unsigned hash = 0;
 639
 640        if (!name)
 641                return 0;
 642
 643        /*
 644         * This effectively just creates a sortable number from the
 645         * last sixteen non-whitespace characters. Last characters
 646         * count "most", so things that end in ".c" sort together.
 647         */
 648        while ((c = *name++) != 0) {
 649                if (isspace(c))
 650                        continue;
 651                hash = (hash >> 2) + (c << 24);
 652        }
 653        return hash;
 654}
 655
 656static void setup_delta_attr_check(struct git_attr_check *check)
 657{
 658        static struct git_attr *attr_delta;
 659
 660        if (!attr_delta)
 661                attr_delta = git_attr("delta", 5);
 662
 663        check[0].attr = attr_delta;
 664}
 665
 666static int no_try_delta(const char *path)
 667{
 668        struct git_attr_check check[1];
 669
 670        setup_delta_attr_check(check);
 671        if (git_checkattr(path, ARRAY_SIZE(check), check))
 672                return 0;
 673        if (ATTR_FALSE(check->value))
 674                return 1;
 675        return 0;
 676}
 677
 678static int add_object_entry(const unsigned char *sha1, enum object_type type,
 679                            const char *name, int exclude)
 680{
 681        struct object_entry *entry;
 682        struct packed_git *p, *found_pack = NULL;
 683        off_t found_offset = 0;
 684        int ix;
 685        unsigned hash = name_hash(name);
 686
 687        ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 688        if (ix >= 0) {
 689                if (exclude) {
 690                        entry = objects + object_ix[ix] - 1;
 691                        if (!entry->preferred_base)
 692                                nr_result--;
 693                        entry->preferred_base = 1;
 694                }
 695                return 0;
 696        }
 697
 698        for (p = packed_git; p; p = p->next) {
 699                off_t offset = find_pack_entry_one(sha1, p);
 700                if (offset) {
 701                        if (!found_pack) {
 702                                found_offset = offset;
 703                                found_pack = p;
 704                        }
 705                        if (exclude)
 706                                break;
 707                        if (incremental)
 708                                return 0;
 709                        if (local && !p->pack_local)
 710                                return 0;
 711                }
 712        }
 713
 714        if (nr_objects >= nr_alloc) {
 715                nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 716                objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 717        }
 718
 719        entry = objects + nr_objects++;
 720        memset(entry, 0, sizeof(*entry));
 721        hashcpy(entry->idx.sha1, sha1);
 722        entry->hash = hash;
 723        if (type)
 724                entry->type = type;
 725        if (exclude)
 726                entry->preferred_base = 1;
 727        else
 728                nr_result++;
 729        if (found_pack) {
 730                entry->in_pack = found_pack;
 731                entry->in_pack_offset = found_offset;
 732        }
 733
 734        if (object_ix_hashsz * 3 <= nr_objects * 4)
 735                rehash_objects();
 736        else
 737                object_ix[-1 - ix] = nr_objects;
 738
 739        display_progress(progress_state, nr_objects);
 740
 741        if (name && no_try_delta(name))
 742                entry->no_try_delta = 1;
 743
 744        return 1;
 745}
 746
 747struct pbase_tree_cache {
 748        unsigned char sha1[20];
 749        int ref;
 750        int temporary;
 751        void *tree_data;
 752        unsigned long tree_size;
 753};
 754
 755static struct pbase_tree_cache *(pbase_tree_cache[256]);
 756static int pbase_tree_cache_ix(const unsigned char *sha1)
 757{
 758        return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 759}
 760static int pbase_tree_cache_ix_incr(int ix)
 761{
 762        return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 763}
 764
 765static struct pbase_tree {
 766        struct pbase_tree *next;
 767        /* This is a phony "cache" entry; we are not
 768         * going to evict it nor find it through _get()
 769         * mechanism -- this is for the toplevel node that
 770         * would almost always change with any commit.
 771         */
 772        struct pbase_tree_cache pcache;
 773} *pbase_tree;
 774
 775static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 776{
 777        struct pbase_tree_cache *ent, *nent;
 778        void *data;
 779        unsigned long size;
 780        enum object_type type;
 781        int neigh;
 782        int my_ix = pbase_tree_cache_ix(sha1);
 783        int available_ix = -1;
 784
 785        /* pbase-tree-cache acts as a limited hashtable.
 786         * your object will be found at your index or within a few
 787         * slots after that slot if it is cached.
 788         */
 789        for (neigh = 0; neigh < 8; neigh++) {
 790                ent = pbase_tree_cache[my_ix];
 791                if (ent && !hashcmp(ent->sha1, sha1)) {
 792                        ent->ref++;
 793                        return ent;
 794                }
 795                else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 796                         ((0 <= available_ix) &&
 797                          (!ent && pbase_tree_cache[available_ix])))
 798                        available_ix = my_ix;
 799                if (!ent)
 800                        break;
 801                my_ix = pbase_tree_cache_ix_incr(my_ix);
 802        }
 803
 804        /* Did not find one.  Either we got a bogus request or
 805         * we need to read and perhaps cache.
 806         */
 807        data = read_sha1_file(sha1, &type, &size);
 808        if (!data)
 809                return NULL;
 810        if (type != OBJ_TREE) {
 811                free(data);
 812                return NULL;
 813        }
 814
 815        /* We need to either cache or return a throwaway copy */
 816
 817        if (available_ix < 0)
 818                ent = NULL;
 819        else {
 820                ent = pbase_tree_cache[available_ix];
 821                my_ix = available_ix;
 822        }
 823
 824        if (!ent) {
 825                nent = xmalloc(sizeof(*nent));
 826                nent->temporary = (available_ix < 0);
 827        }
 828        else {
 829                /* evict and reuse */
 830                free(ent->tree_data);
 831                nent = ent;
 832        }
 833        hashcpy(nent->sha1, sha1);
 834        nent->tree_data = data;
 835        nent->tree_size = size;
 836        nent->ref = 1;
 837        if (!nent->temporary)
 838                pbase_tree_cache[my_ix] = nent;
 839        return nent;
 840}
 841
 842static void pbase_tree_put(struct pbase_tree_cache *cache)
 843{
 844        if (!cache->temporary) {
 845                cache->ref--;
 846                return;
 847        }
 848        free(cache->tree_data);
 849        free(cache);
 850}
 851
 852static int name_cmp_len(const char *name)
 853{
 854        int i;
 855        for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 856                ;
 857        return i;
 858}
 859
 860static void add_pbase_object(struct tree_desc *tree,
 861                             const char *name,
 862                             int cmplen,
 863                             const char *fullname)
 864{
 865        struct name_entry entry;
 866        int cmp;
 867
 868        while (tree_entry(tree,&entry)) {
 869                if (S_ISGITLINK(entry.mode))
 870                        continue;
 871                cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 872                      memcmp(name, entry.path, cmplen);
 873                if (cmp > 0)
 874                        continue;
 875                if (cmp < 0)
 876                        return;
 877                if (name[cmplen] != '/') {
 878                        add_object_entry(entry.sha1,
 879                                         object_type(entry.mode),
 880                                         fullname, 1);
 881                        return;
 882                }
 883                if (S_ISDIR(entry.mode)) {
 884                        struct tree_desc sub;
 885                        struct pbase_tree_cache *tree;
 886                        const char *down = name+cmplen+1;
 887                        int downlen = name_cmp_len(down);
 888
 889                        tree = pbase_tree_get(entry.sha1);
 890                        if (!tree)
 891                                return;
 892                        init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 893
 894                        add_pbase_object(&sub, down, downlen, fullname);
 895                        pbase_tree_put(tree);
 896                }
 897        }
 898}
 899
 900static unsigned *done_pbase_paths;
 901static int done_pbase_paths_num;
 902static int done_pbase_paths_alloc;
 903static int done_pbase_path_pos(unsigned hash)
 904{
 905        int lo = 0;
 906        int hi = done_pbase_paths_num;
 907        while (lo < hi) {
 908                int mi = (hi + lo) / 2;
 909                if (done_pbase_paths[mi] == hash)
 910                        return mi;
 911                if (done_pbase_paths[mi] < hash)
 912                        hi = mi;
 913                else
 914                        lo = mi + 1;
 915        }
 916        return -lo-1;
 917}
 918
 919static int check_pbase_path(unsigned hash)
 920{
 921        int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 922        if (0 <= pos)
 923                return 1;
 924        pos = -pos - 1;
 925        if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 926                done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 927                done_pbase_paths = xrealloc(done_pbase_paths,
 928                                            done_pbase_paths_alloc *
 929                                            sizeof(unsigned));
 930        }
 931        done_pbase_paths_num++;
 932        if (pos < done_pbase_paths_num)
 933                memmove(done_pbase_paths + pos + 1,
 934                        done_pbase_paths + pos,
 935                        (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 936        done_pbase_paths[pos] = hash;
 937        return 0;
 938}
 939
 940static void add_preferred_base_object(const char *name)
 941{
 942        struct pbase_tree *it;
 943        int cmplen;
 944        unsigned hash = name_hash(name);
 945
 946        if (!num_preferred_base || check_pbase_path(hash))
 947                return;
 948
 949        cmplen = name_cmp_len(name);
 950        for (it = pbase_tree; it; it = it->next) {
 951                if (cmplen == 0) {
 952                        add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 953                }
 954                else {
 955                        struct tree_desc tree;
 956                        init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 957                        add_pbase_object(&tree, name, cmplen, name);
 958                }
 959        }
 960}
 961
 962static void add_preferred_base(unsigned char *sha1)
 963{
 964        struct pbase_tree *it;
 965        void *data;
 966        unsigned long size;
 967        unsigned char tree_sha1[20];
 968
 969        if (window <= num_preferred_base++)
 970                return;
 971
 972        data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 973        if (!data)
 974                return;
 975
 976        for (it = pbase_tree; it; it = it->next) {
 977                if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 978                        free(data);
 979                        return;
 980                }
 981        }
 982
 983        it = xcalloc(1, sizeof(*it));
 984        it->next = pbase_tree;
 985        pbase_tree = it;
 986
 987        hashcpy(it->pcache.sha1, tree_sha1);
 988        it->pcache.tree_data = data;
 989        it->pcache.tree_size = size;
 990}
 991
 992static void check_object(struct object_entry *entry)
 993{
 994        if (entry->in_pack) {
 995                struct packed_git *p = entry->in_pack;
 996                struct pack_window *w_curs = NULL;
 997                const unsigned char *base_ref = NULL;
 998                struct object_entry *base_entry;
 999                unsigned long used, used_0;
1000                unsigned int avail;
1001                off_t ofs;
1002                unsigned char *buf, c;
1003
1004                buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1005
1006                /*
1007                 * We want in_pack_type even if we do not reuse delta
1008                 * since non-delta representations could still be reused.
1009                 */
1010                used = unpack_object_header_gently(buf, avail,
1011                                                   &entry->in_pack_type,
1012                                                   &entry->size);
1013
1014                /*
1015                 * Determine if this is a delta and if so whether we can
1016                 * reuse it or not.  Otherwise let's find out as cheaply as
1017                 * possible what the actual type and size for this object is.
1018                 */
1019                switch (entry->in_pack_type) {
1020                default:
1021                        /* Not a delta hence we've already got all we need. */
1022                        entry->type = entry->in_pack_type;
1023                        entry->in_pack_header_size = used;
1024                        unuse_pack(&w_curs);
1025                        return;
1026                case OBJ_REF_DELTA:
1027                        if (reuse_delta && !entry->preferred_base)
1028                                base_ref = use_pack(p, &w_curs,
1029                                                entry->in_pack_offset + used, NULL);
1030                        entry->in_pack_header_size = used + 20;
1031                        break;
1032                case OBJ_OFS_DELTA:
1033                        buf = use_pack(p, &w_curs,
1034                                       entry->in_pack_offset + used, NULL);
1035                        used_0 = 0;
1036                        c = buf[used_0++];
1037                        ofs = c & 127;
1038                        while (c & 128) {
1039                                ofs += 1;
1040                                if (!ofs || MSB(ofs, 7))
1041                                        die("delta base offset overflow in pack for %s",
1042                                            sha1_to_hex(entry->idx.sha1));
1043                                c = buf[used_0++];
1044                                ofs = (ofs << 7) + (c & 127);
1045                        }
1046                        if (ofs >= entry->in_pack_offset)
1047                                die("delta base offset out of bound for %s",
1048                                    sha1_to_hex(entry->idx.sha1));
1049                        ofs = entry->in_pack_offset - ofs;
1050                        if (reuse_delta && !entry->preferred_base) {
1051                                struct revindex_entry *revidx;
1052                                revidx = find_pack_revindex(p, ofs);
1053                                base_ref = nth_packed_object_sha1(p, revidx->nr);
1054                        }
1055                        entry->in_pack_header_size = used + used_0;
1056                        break;
1057                }
1058
1059                if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1060                        /*
1061                         * If base_ref was set above that means we wish to
1062                         * reuse delta data, and we even found that base
1063                         * in the list of objects we want to pack. Goodie!
1064                         *
1065                         * Depth value does not matter - find_deltas() will
1066                         * never consider reused delta as the base object to
1067                         * deltify other objects against, in order to avoid
1068                         * circular deltas.
1069                         */
1070                        entry->type = entry->in_pack_type;
1071                        entry->delta = base_entry;
1072                        entry->delta_sibling = base_entry->delta_child;
1073                        base_entry->delta_child = entry;
1074                        unuse_pack(&w_curs);
1075                        return;
1076                }
1077
1078                if (entry->type) {
1079                        /*
1080                         * This must be a delta and we already know what the
1081                         * final object type is.  Let's extract the actual
1082                         * object size from the delta header.
1083                         */
1084                        entry->size = get_size_from_delta(p, &w_curs,
1085                                        entry->in_pack_offset + entry->in_pack_header_size);
1086                        unuse_pack(&w_curs);
1087                        return;
1088                }
1089
1090                /*
1091                 * No choice but to fall back to the recursive delta walk
1092                 * with sha1_object_info() to find about the object type
1093                 * at this point...
1094                 */
1095                unuse_pack(&w_curs);
1096        }
1097
1098        entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1099        if (entry->type < 0)
1100                die("unable to get type of object %s",
1101                    sha1_to_hex(entry->idx.sha1));
1102}
1103
1104static int pack_offset_sort(const void *_a, const void *_b)
1105{
1106        const struct object_entry *a = *(struct object_entry **)_a;
1107        const struct object_entry *b = *(struct object_entry **)_b;
1108
1109        /* avoid filesystem trashing with loose objects */
1110        if (!a->in_pack && !b->in_pack)
1111                return hashcmp(a->idx.sha1, b->idx.sha1);
1112
1113        if (a->in_pack < b->in_pack)
1114                return -1;
1115        if (a->in_pack > b->in_pack)
1116                return 1;
1117        return a->in_pack_offset < b->in_pack_offset ? -1 :
1118                        (a->in_pack_offset > b->in_pack_offset);
1119}
1120
1121static void get_object_details(void)
1122{
1123        uint32_t i;
1124        struct object_entry **sorted_by_offset;
1125
1126        sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1127        for (i = 0; i < nr_objects; i++)
1128                sorted_by_offset[i] = objects + i;
1129        qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1130
1131        for (i = 0; i < nr_objects; i++)
1132                check_object(sorted_by_offset[i]);
1133
1134        free(sorted_by_offset);
1135}
1136
1137/*
1138 * We search for deltas in a list sorted by type, by filename hash, and then
1139 * by size, so that we see progressively smaller and smaller files.
1140 * That's because we prefer deltas to be from the bigger file
1141 * to the smaller -- deletes are potentially cheaper, but perhaps
1142 * more importantly, the bigger file is likely the more recent
1143 * one.  The deepest deltas are therefore the oldest objects which are
1144 * less susceptible to be accessed often.
1145 */
1146static int type_size_sort(const void *_a, const void *_b)
1147{
1148        const struct object_entry *a = *(struct object_entry **)_a;
1149        const struct object_entry *b = *(struct object_entry **)_b;
1150
1151        if (a->type > b->type)
1152                return -1;
1153        if (a->type < b->type)
1154                return 1;
1155        if (a->hash > b->hash)
1156                return -1;
1157        if (a->hash < b->hash)
1158                return 1;
1159        if (a->preferred_base > b->preferred_base)
1160                return -1;
1161        if (a->preferred_base < b->preferred_base)
1162                return 1;
1163        if (a->size > b->size)
1164                return -1;
1165        if (a->size < b->size)
1166                return 1;
1167        return a < b ? -1 : (a > b);  /* newest first */
1168}
1169
1170struct unpacked {
1171        struct object_entry *entry;
1172        void *data;
1173        struct delta_index *index;
1174        unsigned depth;
1175};
1176
1177static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1178                           unsigned long delta_size)
1179{
1180        if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1181                return 0;
1182
1183        if (delta_size < cache_max_small_delta_size)
1184                return 1;
1185
1186        /* cache delta, if objects are large enough compared to delta size */
1187        if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1188                return 1;
1189
1190        return 0;
1191}
1192
1193#ifdef THREADED_DELTA_SEARCH
1194
1195static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1196#define read_lock()             pthread_mutex_lock(&read_mutex)
1197#define read_unlock()           pthread_mutex_unlock(&read_mutex)
1198
1199static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1200#define cache_lock()            pthread_mutex_lock(&cache_mutex)
1201#define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1202
1203static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1204#define progress_lock()         pthread_mutex_lock(&progress_mutex)
1205#define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1206
1207#else
1208
1209#define read_lock()             (void)0
1210#define read_unlock()           (void)0
1211#define cache_lock()            (void)0
1212#define cache_unlock()          (void)0
1213#define progress_lock()         (void)0
1214#define progress_unlock()       (void)0
1215
1216#endif
1217
1218static int try_delta(struct unpacked *trg, struct unpacked *src,
1219                     unsigned max_depth, unsigned long *mem_usage)
1220{
1221        struct object_entry *trg_entry = trg->entry;
1222        struct object_entry *src_entry = src->entry;
1223        unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1224        unsigned ref_depth;
1225        enum object_type type;
1226        void *delta_buf;
1227
1228        /* Don't bother doing diffs between different types */
1229        if (trg_entry->type != src_entry->type)
1230                return -1;
1231
1232        /*
1233         * We do not bother to try a delta that we discarded
1234         * on an earlier try, but only when reusing delta data.
1235         */
1236        if (reuse_delta && trg_entry->in_pack &&
1237            trg_entry->in_pack == src_entry->in_pack &&
1238            trg_entry->in_pack_type != OBJ_REF_DELTA &&
1239            trg_entry->in_pack_type != OBJ_OFS_DELTA)
1240                return 0;
1241
1242        /* Let's not bust the allowed depth. */
1243        if (src->depth >= max_depth)
1244                return 0;
1245
1246        /* Now some size filtering heuristics. */
1247        trg_size = trg_entry->size;
1248        if (!trg_entry->delta) {
1249                max_size = trg_size/2 - 20;
1250                ref_depth = 1;
1251        } else {
1252                max_size = trg_entry->delta_size;
1253                ref_depth = trg->depth;
1254        }
1255        max_size = max_size * (max_depth - src->depth) /
1256                                                (max_depth - ref_depth + 1);
1257        if (max_size == 0)
1258                return 0;
1259        src_size = src_entry->size;
1260        sizediff = src_size < trg_size ? trg_size - src_size : 0;
1261        if (sizediff >= max_size)
1262                return 0;
1263        if (trg_size < src_size / 32)
1264                return 0;
1265
1266        /* Load data if not already done */
1267        if (!trg->data) {
1268                read_lock();
1269                trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1270                read_unlock();
1271                if (!trg->data)
1272                        die("object %s cannot be read",
1273                            sha1_to_hex(trg_entry->idx.sha1));
1274                if (sz != trg_size)
1275                        die("object %s inconsistent object length (%lu vs %lu)",
1276                            sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1277                *mem_usage += sz;
1278        }
1279        if (!src->data) {
1280                read_lock();
1281                src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1282                read_unlock();
1283                if (!src->data)
1284                        die("object %s cannot be read",
1285                            sha1_to_hex(src_entry->idx.sha1));
1286                if (sz != src_size)
1287                        die("object %s inconsistent object length (%lu vs %lu)",
1288                            sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1289                *mem_usage += sz;
1290        }
1291        if (!src->index) {
1292                src->index = create_delta_index(src->data, src_size);
1293                if (!src->index) {
1294                        static int warned = 0;
1295                        if (!warned++)
1296                                warning("suboptimal pack - out of memory");
1297                        return 0;
1298                }
1299                *mem_usage += sizeof_delta_index(src->index);
1300        }
1301
1302        delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1303        if (!delta_buf)
1304                return 0;
1305
1306        if (trg_entry->delta) {
1307                /* Prefer only shallower same-sized deltas. */
1308                if (delta_size == trg_entry->delta_size &&
1309                    src->depth + 1 >= trg->depth) {
1310                        free(delta_buf);
1311                        return 0;
1312                }
1313        }
1314
1315        /*
1316         * Handle memory allocation outside of the cache
1317         * accounting lock.  Compiler will optimize the strangeness
1318         * away when THREADED_DELTA_SEARCH is not defined.
1319         */
1320        free(trg_entry->delta_data);
1321        cache_lock();
1322        if (trg_entry->delta_data) {
1323                delta_cache_size -= trg_entry->delta_size;
1324                trg_entry->delta_data = NULL;
1325        }
1326        if (delta_cacheable(src_size, trg_size, delta_size)) {
1327                delta_cache_size += delta_size;
1328                cache_unlock();
1329                trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1330        } else {
1331                cache_unlock();
1332                free(delta_buf);
1333        }
1334
1335        trg_entry->delta = src_entry;
1336        trg_entry->delta_size = delta_size;
1337        trg->depth = src->depth + 1;
1338
1339        return 1;
1340}
1341
1342static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1343{
1344        struct object_entry *child = me->delta_child;
1345        unsigned int m = n;
1346        while (child) {
1347                unsigned int c = check_delta_limit(child, n + 1);
1348                if (m < c)
1349                        m = c;
1350                child = child->delta_sibling;
1351        }
1352        return m;
1353}
1354
1355static unsigned long free_unpacked(struct unpacked *n)
1356{
1357        unsigned long freed_mem = sizeof_delta_index(n->index);
1358        free_delta_index(n->index);
1359        n->index = NULL;
1360        if (n->data) {
1361                freed_mem += n->entry->size;
1362                free(n->data);
1363                n->data = NULL;
1364        }
1365        n->entry = NULL;
1366        n->depth = 0;
1367        return freed_mem;
1368}
1369
1370static void find_deltas(struct object_entry **list, unsigned *list_size,
1371                        int window, int depth, unsigned *processed)
1372{
1373        uint32_t i, idx = 0, count = 0;
1374        unsigned int array_size = window * sizeof(struct unpacked);
1375        struct unpacked *array;
1376        unsigned long mem_usage = 0;
1377
1378        array = xmalloc(array_size);
1379        memset(array, 0, array_size);
1380
1381        for (;;) {
1382                struct object_entry *entry = *list++;
1383                struct unpacked *n = array + idx;
1384                int j, max_depth, best_base = -1;
1385
1386                progress_lock();
1387                if (!*list_size) {
1388                        progress_unlock();
1389                        break;
1390                }
1391                (*list_size)--;
1392                if (!entry->preferred_base) {
1393                        (*processed)++;
1394                        display_progress(progress_state, *processed);
1395                }
1396                progress_unlock();
1397
1398                mem_usage -= free_unpacked(n);
1399                n->entry = entry;
1400
1401                while (window_memory_limit &&
1402                       mem_usage > window_memory_limit &&
1403                       count > 1) {
1404                        uint32_t tail = (idx + window - count) % window;
1405                        mem_usage -= free_unpacked(array + tail);
1406                        count--;
1407                }
1408
1409                /* We do not compute delta to *create* objects we are not
1410                 * going to pack.
1411                 */
1412                if (entry->preferred_base)
1413                        goto next;
1414
1415                /*
1416                 * If the current object is at pack edge, take the depth the
1417                 * objects that depend on the current object into account
1418                 * otherwise they would become too deep.
1419                 */
1420                max_depth = depth;
1421                if (entry->delta_child) {
1422                        max_depth -= check_delta_limit(entry, 0);
1423                        if (max_depth <= 0)
1424                                goto next;
1425                }
1426
1427                j = window;
1428                while (--j > 0) {
1429                        int ret;
1430                        uint32_t other_idx = idx + j;
1431                        struct unpacked *m;
1432                        if (other_idx >= window)
1433                                other_idx -= window;
1434                        m = array + other_idx;
1435                        if (!m->entry)
1436                                break;
1437                        ret = try_delta(n, m, max_depth, &mem_usage);
1438                        if (ret < 0)
1439                                break;
1440                        else if (ret > 0)
1441                                best_base = other_idx;
1442                }
1443
1444                /*
1445                 * If we decided to cache the delta data, then it is best
1446                 * to compress it right away.  First because we have to do
1447                 * it anyway, and doing it here while we're threaded will
1448                 * save a lot of time in the non threaded write phase,
1449                 * as well as allow for caching more deltas within
1450                 * the same cache size limit.
1451                 * ...
1452                 * But only if not writing to stdout, since in that case
1453                 * the network is most likely throttling writes anyway,
1454                 * and therefore it is best to go to the write phase ASAP
1455                 * instead, as we can afford spending more time compressing
1456                 * between writes at that moment.
1457                 */
1458                if (entry->delta_data && !pack_to_stdout) {
1459                        entry->z_delta_size = do_compress(&entry->delta_data,
1460                                                          entry->delta_size);
1461                        cache_lock();
1462                        delta_cache_size -= entry->delta_size;
1463                        delta_cache_size += entry->z_delta_size;
1464                        cache_unlock();
1465                }
1466
1467                /* if we made n a delta, and if n is already at max
1468                 * depth, leaving it in the window is pointless.  we
1469                 * should evict it first.
1470                 */
1471                if (entry->delta && max_depth <= n->depth)
1472                        continue;
1473
1474                /*
1475                 * Move the best delta base up in the window, after the
1476                 * currently deltified object, to keep it longer.  It will
1477                 * be the first base object to be attempted next.
1478                 */
1479                if (entry->delta) {
1480                        struct unpacked swap = array[best_base];
1481                        int dist = (window + idx - best_base) % window;
1482                        int dst = best_base;
1483                        while (dist--) {
1484                                int src = (dst + 1) % window;
1485                                array[dst] = array[src];
1486                                dst = src;
1487                        }
1488                        array[dst] = swap;
1489                }
1490
1491                next:
1492                idx++;
1493                if (count + 1 < window)
1494                        count++;
1495                if (idx >= window)
1496                        idx = 0;
1497        }
1498
1499        for (i = 0; i < window; ++i) {
1500                free_delta_index(array[i].index);
1501                free(array[i].data);
1502        }
1503        free(array);
1504}
1505
1506#ifdef THREADED_DELTA_SEARCH
1507
1508/*
1509 * The main thread waits on the condition that (at least) one of the workers
1510 * has stopped working (which is indicated in the .working member of
1511 * struct thread_params).
1512 * When a work thread has completed its work, it sets .working to 0 and
1513 * signals the main thread and waits on the condition that .data_ready
1514 * becomes 1.
1515 */
1516
1517struct thread_params {
1518        pthread_t thread;
1519        struct object_entry **list;
1520        unsigned list_size;
1521        unsigned remaining;
1522        int window;
1523        int depth;
1524        int working;
1525        int data_ready;
1526        pthread_mutex_t mutex;
1527        pthread_cond_t cond;
1528        unsigned *processed;
1529};
1530
1531static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
1532
1533static void *threaded_find_deltas(void *arg)
1534{
1535        struct thread_params *me = arg;
1536
1537        while (me->remaining) {
1538                find_deltas(me->list, &me->remaining,
1539                            me->window, me->depth, me->processed);
1540
1541                progress_lock();
1542                me->working = 0;
1543                pthread_cond_signal(&progress_cond);
1544                progress_unlock();
1545
1546                /*
1547                 * We must not set ->data_ready before we wait on the
1548                 * condition because the main thread may have set it to 1
1549                 * before we get here. In order to be sure that new
1550                 * work is available if we see 1 in ->data_ready, it
1551                 * was initialized to 0 before this thread was spawned
1552                 * and we reset it to 0 right away.
1553                 */
1554                pthread_mutex_lock(&me->mutex);
1555                while (!me->data_ready)
1556                        pthread_cond_wait(&me->cond, &me->mutex);
1557                me->data_ready = 0;
1558                pthread_mutex_unlock(&me->mutex);
1559        }
1560        /* leave ->working 1 so that this doesn't get more work assigned */
1561        return NULL;
1562}
1563
1564static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1565                           int window, int depth, unsigned *processed)
1566{
1567        struct thread_params p[delta_search_threads];
1568        int i, ret, active_threads = 0;
1569
1570        if (delta_search_threads <= 1) {
1571                find_deltas(list, &list_size, window, depth, processed);
1572                return;
1573        }
1574
1575        /* Partition the work amongst work threads. */
1576        for (i = 0; i < delta_search_threads; i++) {
1577                unsigned sub_size = list_size / (delta_search_threads - i);
1578
1579                p[i].window = window;
1580                p[i].depth = depth;
1581                p[i].processed = processed;
1582                p[i].working = 1;
1583                p[i].data_ready = 0;
1584
1585                /* try to split chunks on "path" boundaries */
1586                while (sub_size && sub_size < list_size &&
1587                       list[sub_size]->hash &&
1588                       list[sub_size]->hash == list[sub_size-1]->hash)
1589                        sub_size++;
1590
1591                p[i].list = list;
1592                p[i].list_size = sub_size;
1593                p[i].remaining = sub_size;
1594
1595                list += sub_size;
1596                list_size -= sub_size;
1597        }
1598
1599        /* Start work threads. */
1600        for (i = 0; i < delta_search_threads; i++) {
1601                if (!p[i].list_size)
1602                        continue;
1603                pthread_mutex_init(&p[i].mutex, NULL);
1604                pthread_cond_init(&p[i].cond, NULL);
1605                ret = pthread_create(&p[i].thread, NULL,
1606                                     threaded_find_deltas, &p[i]);
1607                if (ret)
1608                        die("unable to create thread: %s", strerror(ret));
1609                active_threads++;
1610        }
1611
1612        /*
1613         * Now let's wait for work completion.  Each time a thread is done
1614         * with its work, we steal half of the remaining work from the
1615         * thread with the largest number of unprocessed objects and give
1616         * it to that newly idle thread.  This ensure good load balancing
1617         * until the remaining object list segments are simply too short
1618         * to be worth splitting anymore.
1619         */
1620        while (active_threads) {
1621                struct thread_params *target = NULL;
1622                struct thread_params *victim = NULL;
1623                unsigned sub_size = 0;
1624
1625                progress_lock();
1626                for (;;) {
1627                        for (i = 0; !target && i < delta_search_threads; i++)
1628                                if (!p[i].working)
1629                                        target = &p[i];
1630                        if (target)
1631                                break;
1632                        pthread_cond_wait(&progress_cond, &progress_mutex);
1633                }
1634
1635                for (i = 0; i < delta_search_threads; i++)
1636                        if (p[i].remaining > 2*window &&
1637                            (!victim || victim->remaining < p[i].remaining))
1638                                victim = &p[i];
1639                if (victim) {
1640                        sub_size = victim->remaining / 2;
1641                        list = victim->list + victim->list_size - sub_size;
1642                        while (sub_size && list[0]->hash &&
1643                               list[0]->hash == list[-1]->hash) {
1644                                list++;
1645                                sub_size--;
1646                        }
1647                        if (!sub_size) {
1648                                /*
1649                                 * It is possible for some "paths" to have
1650                                 * so many objects that no hash boundary
1651                                 * might be found.  Let's just steal the
1652                                 * exact half in that case.
1653                                 */
1654                                sub_size = victim->remaining / 2;
1655                                list -= sub_size;
1656                        }
1657                        target->list = list;
1658                        victim->list_size -= sub_size;
1659                        victim->remaining -= sub_size;
1660                }
1661                target->list_size = sub_size;
1662                target->remaining = sub_size;
1663                target->working = 1;
1664                progress_unlock();
1665
1666                pthread_mutex_lock(&target->mutex);
1667                target->data_ready = 1;
1668                pthread_cond_signal(&target->cond);
1669                pthread_mutex_unlock(&target->mutex);
1670
1671                if (!sub_size) {
1672                        pthread_join(target->thread, NULL);
1673                        pthread_cond_destroy(&target->cond);
1674                        pthread_mutex_destroy(&target->mutex);
1675                        active_threads--;
1676                }
1677        }
1678}
1679
1680#else
1681#define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1682#endif
1683
1684static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1685{
1686        unsigned char peeled[20];
1687
1688        if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1689            !peel_ref(path, peeled)        && /* peelable? */
1690            !is_null_sha1(peeled)          && /* annotated tag? */
1691            locate_object_entry(peeled))      /* object packed? */
1692                add_object_entry(sha1, OBJ_TAG, NULL, 0);
1693        return 0;
1694}
1695
1696static void prepare_pack(int window, int depth)
1697{
1698        struct object_entry **delta_list;
1699        uint32_t i, nr_deltas;
1700        unsigned n;
1701
1702        get_object_details();
1703
1704        if (!nr_objects || !window || !depth)
1705                return;
1706
1707        delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1708        nr_deltas = n = 0;
1709
1710        for (i = 0; i < nr_objects; i++) {
1711                struct object_entry *entry = objects + i;
1712
1713                if (entry->delta)
1714                        /* This happens if we decided to reuse existing
1715                         * delta from a pack.  "reuse_delta &&" is implied.
1716                         */
1717                        continue;
1718
1719                if (entry->size < 50)
1720                        continue;
1721
1722                if (entry->no_try_delta)
1723                        continue;
1724
1725                if (!entry->preferred_base)
1726                        nr_deltas++;
1727
1728                delta_list[n++] = entry;
1729        }
1730
1731        if (nr_deltas && n > 1) {
1732                unsigned nr_done = 0;
1733                if (progress)
1734                        progress_state = start_progress("Compressing objects",
1735                                                        nr_deltas);
1736                qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1737                ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1738                stop_progress(&progress_state);
1739                if (nr_done != nr_deltas)
1740                        die("inconsistency with delta count");
1741        }
1742        free(delta_list);
1743}
1744
1745static int git_pack_config(const char *k, const char *v, void *cb)
1746{
1747        if(!strcmp(k, "pack.window")) {
1748                window = git_config_int(k, v);
1749                return 0;
1750        }
1751        if (!strcmp(k, "pack.windowmemory")) {
1752                window_memory_limit = git_config_ulong(k, v);
1753                return 0;
1754        }
1755        if (!strcmp(k, "pack.depth")) {
1756                depth = git_config_int(k, v);
1757                return 0;
1758        }
1759        if (!strcmp(k, "pack.compression")) {
1760                int level = git_config_int(k, v);
1761                if (level == -1)
1762                        level = Z_DEFAULT_COMPRESSION;
1763                else if (level < 0 || level > Z_BEST_COMPRESSION)
1764                        die("bad pack compression level %d", level);
1765                pack_compression_level = level;
1766                pack_compression_seen = 1;
1767                return 0;
1768        }
1769        if (!strcmp(k, "pack.deltacachesize")) {
1770                max_delta_cache_size = git_config_int(k, v);
1771                return 0;
1772        }
1773        if (!strcmp(k, "pack.deltacachelimit")) {
1774                cache_max_small_delta_size = git_config_int(k, v);
1775                return 0;
1776        }
1777        if (!strcmp(k, "pack.threads")) {
1778                delta_search_threads = git_config_int(k, v);
1779                if (delta_search_threads < 0)
1780                        die("invalid number of threads specified (%d)",
1781                            delta_search_threads);
1782#ifndef THREADED_DELTA_SEARCH
1783                if (delta_search_threads != 1)
1784                        warning("no threads support, ignoring %s", k);
1785#endif
1786                return 0;
1787        }
1788        if (!strcmp(k, "pack.indexversion")) {
1789                pack_idx_default_version = git_config_int(k, v);
1790                if (pack_idx_default_version > 2)
1791                        die("bad pack.indexversion=%"PRIu32,
1792                                pack_idx_default_version);
1793                return 0;
1794        }
1795        if (!strcmp(k, "pack.packsizelimit")) {
1796                pack_size_limit_cfg = git_config_ulong(k, v);
1797                return 0;
1798        }
1799        return git_default_config(k, v, cb);
1800}
1801
1802static void read_object_list_from_stdin(void)
1803{
1804        char line[40 + 1 + PATH_MAX + 2];
1805        unsigned char sha1[20];
1806
1807        for (;;) {
1808                if (!fgets(line, sizeof(line), stdin)) {
1809                        if (feof(stdin))
1810                                break;
1811                        if (!ferror(stdin))
1812                                die("fgets returned NULL, not EOF, not error!");
1813                        if (errno != EINTR)
1814                                die("fgets: %s", strerror(errno));
1815                        clearerr(stdin);
1816                        continue;
1817                }
1818                if (line[0] == '-') {
1819                        if (get_sha1_hex(line+1, sha1))
1820                                die("expected edge sha1, got garbage:\n %s",
1821                                    line);
1822                        add_preferred_base(sha1);
1823                        continue;
1824                }
1825                if (get_sha1_hex(line, sha1))
1826                        die("expected sha1, got garbage:\n %s", line);
1827
1828                add_preferred_base_object(line+41);
1829                add_object_entry(sha1, 0, line+41, 0);
1830        }
1831}
1832
1833#define OBJECT_ADDED (1u<<20)
1834
1835static void show_commit(struct commit *commit)
1836{
1837        add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1838        commit->object.flags |= OBJECT_ADDED;
1839}
1840
1841static void show_object(struct object_array_entry *p)
1842{
1843        add_preferred_base_object(p->name);
1844        add_object_entry(p->item->sha1, p->item->type, p->name, 0);
1845        p->item->flags |= OBJECT_ADDED;
1846}
1847
1848static void show_edge(struct commit *commit)
1849{
1850        add_preferred_base(commit->object.sha1);
1851}
1852
1853struct in_pack_object {
1854        off_t offset;
1855        struct object *object;
1856};
1857
1858struct in_pack {
1859        int alloc;
1860        int nr;
1861        struct in_pack_object *array;
1862};
1863
1864static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1865{
1866        in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1867        in_pack->array[in_pack->nr].object = object;
1868        in_pack->nr++;
1869}
1870
1871/*
1872 * Compare the objects in the offset order, in order to emulate the
1873 * "git-rev-list --objects" output that produced the pack originally.
1874 */
1875static int ofscmp(const void *a_, const void *b_)
1876{
1877        struct in_pack_object *a = (struct in_pack_object *)a_;
1878        struct in_pack_object *b = (struct in_pack_object *)b_;
1879
1880        if (a->offset < b->offset)
1881                return -1;
1882        else if (a->offset > b->offset)
1883                return 1;
1884        else
1885                return hashcmp(a->object->sha1, b->object->sha1);
1886}
1887
1888static void add_objects_in_unpacked_packs(struct rev_info *revs)
1889{
1890        struct packed_git *p;
1891        struct in_pack in_pack;
1892        uint32_t i;
1893
1894        memset(&in_pack, 0, sizeof(in_pack));
1895
1896        for (p = packed_git; p; p = p->next) {
1897                const unsigned char *sha1;
1898                struct object *o;
1899
1900                for (i = 0; i < revs->num_ignore_packed; i++) {
1901                        if (matches_pack_name(p, revs->ignore_packed[i]))
1902                                break;
1903                }
1904                if (revs->num_ignore_packed <= i)
1905                        continue;
1906                if (open_pack_index(p))
1907                        die("cannot open pack index");
1908
1909                ALLOC_GROW(in_pack.array,
1910                           in_pack.nr + p->num_objects,
1911                           in_pack.alloc);
1912
1913                for (i = 0; i < p->num_objects; i++) {
1914                        sha1 = nth_packed_object_sha1(p, i);
1915                        o = lookup_unknown_object(sha1);
1916                        if (!(o->flags & OBJECT_ADDED))
1917                                mark_in_pack_object(o, p, &in_pack);
1918                        o->flags |= OBJECT_ADDED;
1919                }
1920        }
1921
1922        if (in_pack.nr) {
1923                qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
1924                      ofscmp);
1925                for (i = 0; i < in_pack.nr; i++) {
1926                        struct object *o = in_pack.array[i].object;
1927                        add_object_entry(o->sha1, o->type, "", 0);
1928                }
1929        }
1930        free(in_pack.array);
1931}
1932
1933static void loosen_unused_packed_objects(struct rev_info *revs)
1934{
1935        struct packed_git *p;
1936        uint32_t i;
1937        const unsigned char *sha1;
1938
1939        for (p = packed_git; p; p = p->next) {
1940                for (i = 0; i < revs->num_ignore_packed; i++) {
1941                        if (matches_pack_name(p, revs->ignore_packed[i]))
1942                                break;
1943                }
1944                if (revs->num_ignore_packed <= i)
1945                        continue;
1946
1947                if (open_pack_index(p))
1948                        die("cannot open pack index");
1949
1950                for (i = 0; i < p->num_objects; i++) {
1951                        sha1 = nth_packed_object_sha1(p, i);
1952                        if (!locate_object_entry(sha1))
1953                                if (force_object_loose(sha1, p->mtime))
1954                                        die("unable to force loose object");
1955                }
1956        }
1957}
1958
1959static void get_object_list(int ac, const char **av)
1960{
1961        struct rev_info revs;
1962        char line[1000];
1963        int flags = 0;
1964
1965        init_revisions(&revs, NULL);
1966        save_commit_buffer = 0;
1967        setup_revisions(ac, av, &revs, NULL);
1968
1969        while (fgets(line, sizeof(line), stdin) != NULL) {
1970                int len = strlen(line);
1971                if (len && line[len - 1] == '\n')
1972                        line[--len] = 0;
1973                if (!len)
1974                        break;
1975                if (*line == '-') {
1976                        if (!strcmp(line, "--not")) {
1977                                flags ^= UNINTERESTING;
1978                                continue;
1979                        }
1980                        die("not a rev '%s'", line);
1981                }
1982                if (handle_revision_arg(line, &revs, flags, 1))
1983                        die("bad revision '%s'", line);
1984        }
1985
1986        if (prepare_revision_walk(&revs))
1987                die("revision walk setup failed");
1988        mark_edges_uninteresting(revs.commits, &revs, show_edge);
1989        traverse_commit_list(&revs, show_commit, show_object);
1990
1991        if (keep_unreachable)
1992                add_objects_in_unpacked_packs(&revs);
1993        if (unpack_unreachable)
1994                loosen_unused_packed_objects(&revs);
1995}
1996
1997static int adjust_perm(const char *path, mode_t mode)
1998{
1999        if (chmod(path, mode))
2000                return -1;
2001        return adjust_shared_perm(path);
2002}
2003
2004int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2005{
2006        int use_internal_rev_list = 0;
2007        int thin = 0;
2008        uint32_t i;
2009        const char **rp_av;
2010        int rp_ac_alloc = 64;
2011        int rp_ac;
2012
2013        rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2014
2015        rp_av[0] = "pack-objects";
2016        rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2017        rp_ac = 2;
2018
2019        git_config(git_pack_config, NULL);
2020        if (!pack_compression_seen && core_compression_seen)
2021                pack_compression_level = core_compression_level;
2022
2023        progress = isatty(2);
2024        for (i = 1; i < argc; i++) {
2025                const char *arg = argv[i];
2026
2027                if (*arg != '-')
2028                        break;
2029
2030                if (!strcmp("--non-empty", arg)) {
2031                        non_empty = 1;
2032                        continue;
2033                }
2034                if (!strcmp("--local", arg)) {
2035                        local = 1;
2036                        continue;
2037                }
2038                if (!strcmp("--incremental", arg)) {
2039                        incremental = 1;
2040                        continue;
2041                }
2042                if (!prefixcmp(arg, "--compression=")) {
2043                        char *end;
2044                        int level = strtoul(arg+14, &end, 0);
2045                        if (!arg[14] || *end)
2046                                usage(pack_usage);
2047                        if (level == -1)
2048                                level = Z_DEFAULT_COMPRESSION;
2049                        else if (level < 0 || level > Z_BEST_COMPRESSION)
2050                                die("bad pack compression level %d", level);
2051                        pack_compression_level = level;
2052                        continue;
2053                }
2054                if (!prefixcmp(arg, "--max-pack-size=")) {
2055                        char *end;
2056                        pack_size_limit_cfg = 0;
2057                        pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2058                        if (!arg[16] || *end)
2059                                usage(pack_usage);
2060                        continue;
2061                }
2062                if (!prefixcmp(arg, "--window=")) {
2063                        char *end;
2064                        window = strtoul(arg+9, &end, 0);
2065                        if (!arg[9] || *end)
2066                                usage(pack_usage);
2067                        continue;
2068                }
2069                if (!prefixcmp(arg, "--window-memory=")) {
2070                        if (!git_parse_ulong(arg+16, &window_memory_limit))
2071                                usage(pack_usage);
2072                        continue;
2073                }
2074                if (!prefixcmp(arg, "--threads=")) {
2075                        char *end;
2076                        delta_search_threads = strtoul(arg+10, &end, 0);
2077                        if (!arg[10] || *end || delta_search_threads < 0)
2078                                usage(pack_usage);
2079#ifndef THREADED_DELTA_SEARCH
2080                        if (delta_search_threads != 1)
2081                                warning("no threads support, "
2082                                        "ignoring %s", arg);
2083#endif
2084                        continue;
2085                }
2086                if (!prefixcmp(arg, "--depth=")) {
2087                        char *end;
2088                        depth = strtoul(arg+8, &end, 0);
2089                        if (!arg[8] || *end)
2090                                usage(pack_usage);
2091                        continue;
2092                }
2093                if (!strcmp("--progress", arg)) {
2094                        progress = 1;
2095                        continue;
2096                }
2097                if (!strcmp("--all-progress", arg)) {
2098                        progress = 2;
2099                        continue;
2100                }
2101                if (!strcmp("-q", arg)) {
2102                        progress = 0;
2103                        continue;
2104                }
2105                if (!strcmp("--no-reuse-delta", arg)) {
2106                        reuse_delta = 0;
2107                        continue;
2108                }
2109                if (!strcmp("--no-reuse-object", arg)) {
2110                        reuse_object = reuse_delta = 0;
2111                        continue;
2112                }
2113                if (!strcmp("--delta-base-offset", arg)) {
2114                        allow_ofs_delta = 1;
2115                        continue;
2116                }
2117                if (!strcmp("--stdout", arg)) {
2118                        pack_to_stdout = 1;
2119                        continue;
2120                }
2121                if (!strcmp("--revs", arg)) {
2122                        use_internal_rev_list = 1;
2123                        continue;
2124                }
2125                if (!strcmp("--keep-unreachable", arg)) {
2126                        keep_unreachable = 1;
2127                        continue;
2128                }
2129                if (!strcmp("--unpack-unreachable", arg)) {
2130                        unpack_unreachable = 1;
2131                        continue;
2132                }
2133                if (!strcmp("--include-tag", arg)) {
2134                        include_tag = 1;
2135                        continue;
2136                }
2137                if (!strcmp("--unpacked", arg) ||
2138                    !prefixcmp(arg, "--unpacked=") ||
2139                    !strcmp("--reflog", arg) ||
2140                    !strcmp("--all", arg)) {
2141                        use_internal_rev_list = 1;
2142                        if (rp_ac >= rp_ac_alloc - 1) {
2143                                rp_ac_alloc = alloc_nr(rp_ac_alloc);
2144                                rp_av = xrealloc(rp_av,
2145                                                 rp_ac_alloc * sizeof(*rp_av));
2146                        }
2147                        rp_av[rp_ac++] = arg;
2148                        continue;
2149                }
2150                if (!strcmp("--thin", arg)) {
2151                        use_internal_rev_list = 1;
2152                        thin = 1;
2153                        rp_av[1] = "--objects-edge";
2154                        continue;
2155                }
2156                if (!prefixcmp(arg, "--index-version=")) {
2157                        char *c;
2158                        pack_idx_default_version = strtoul(arg + 16, &c, 10);
2159                        if (pack_idx_default_version > 2)
2160                                die("bad %s", arg);
2161                        if (*c == ',')
2162                                pack_idx_off32_limit = strtoul(c+1, &c, 0);
2163                        if (*c || pack_idx_off32_limit & 0x80000000)
2164                                die("bad %s", arg);
2165                        continue;
2166                }
2167                usage(pack_usage);
2168        }
2169
2170        /* Traditionally "pack-objects [options] base extra" failed;
2171         * we would however want to take refs parameter that would
2172         * have been given to upstream rev-list ourselves, which means
2173         * we somehow want to say what the base name is.  So the
2174         * syntax would be:
2175         *
2176         * pack-objects [options] base <refs...>
2177         *
2178         * in other words, we would treat the first non-option as the
2179         * base_name and send everything else to the internal revision
2180         * walker.
2181         */
2182
2183        if (!pack_to_stdout)
2184                base_name = argv[i++];
2185
2186        if (pack_to_stdout != !base_name)
2187                usage(pack_usage);
2188
2189        if (!pack_to_stdout && !pack_size_limit)
2190                pack_size_limit = pack_size_limit_cfg;
2191
2192        if (pack_to_stdout && pack_size_limit)
2193                die("--max-pack-size cannot be used to build a pack for transfer.");
2194
2195        if (!pack_to_stdout && thin)
2196                die("--thin cannot be used to build an indexable pack.");
2197
2198        if (keep_unreachable && unpack_unreachable)
2199                die("--keep-unreachable and --unpack-unreachable are incompatible.");
2200
2201#ifdef THREADED_DELTA_SEARCH
2202        if (!delta_search_threads)      /* --threads=0 means autodetect */
2203                delta_search_threads = online_cpus();
2204#endif
2205
2206        prepare_packed_git();
2207
2208        if (progress)
2209                progress_state = start_progress("Counting objects", 0);
2210        if (!use_internal_rev_list)
2211                read_object_list_from_stdin();
2212        else {
2213                rp_av[rp_ac] = NULL;
2214                get_object_list(rp_ac, rp_av);
2215        }
2216        if (include_tag && nr_result)
2217                for_each_ref(add_ref_tag, NULL);
2218        stop_progress(&progress_state);
2219
2220        if (non_empty && !nr_result)
2221                return 0;
2222        if (nr_result)
2223                prepare_pack(window, depth);
2224        write_pack_file();
2225        if (progress)
2226                fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2227                        " reused %"PRIu32" (delta %"PRIu32")\n",
2228                        written, written_delta, reused, reused_delta);
2229        return 0;
2230}