builtin-pack-objects.con commit Add a small patch-mode testing library (b319ef7)
   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 ignore_packed_keep;
  75static int allow_ofs_delta;
  76static const char *base_name;
  77static int progress = 1;
  78static int window = 10;
  79static uint32_t pack_size_limit, pack_size_limit_cfg;
  80static int depth = 50;
  81static int delta_search_threads;
  82static int pack_to_stdout;
  83static int num_preferred_base;
  84static struct progress *progress_state;
  85static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  86static int pack_compression_seen;
  87
  88static unsigned long delta_cache_size = 0;
  89static unsigned long max_delta_cache_size = 0;
  90static unsigned long cache_max_small_delta_size = 1000;
  91
  92static unsigned long window_memory_limit = 0;
  93
  94/*
  95 * The object names in objects array are hashed with this hashtable,
  96 * to help looking up the entry by object name.
  97 * This hashtable is built after all the objects are seen.
  98 */
  99static int *object_ix;
 100static int object_ix_hashsz;
 101
 102/*
 103 * stats
 104 */
 105static uint32_t written, written_delta;
 106static uint32_t reused, reused_delta;
 107
 108
 109static void *get_delta(struct object_entry *entry)
 110{
 111        unsigned long size, base_size, delta_size;
 112        void *buf, *base_buf, *delta_buf;
 113        enum object_type type;
 114
 115        buf = read_sha1_file(entry->idx.sha1, &type, &size);
 116        if (!buf)
 117                die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 118        base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
 119        if (!base_buf)
 120                die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 121        delta_buf = diff_delta(base_buf, base_size,
 122                               buf, size, &delta_size, 0);
 123        if (!delta_buf || delta_size != entry->delta_size)
 124                die("delta size changed");
 125        free(buf);
 126        free(base_buf);
 127        return delta_buf;
 128}
 129
 130static unsigned long do_compress(void **pptr, unsigned long size)
 131{
 132        z_stream stream;
 133        void *in, *out;
 134        unsigned long maxsize;
 135
 136        memset(&stream, 0, sizeof(stream));
 137        deflateInit(&stream, pack_compression_level);
 138        maxsize = deflateBound(&stream, size);
 139
 140        in = *pptr;
 141        out = xmalloc(maxsize);
 142        *pptr = out;
 143
 144        stream.next_in = in;
 145        stream.avail_in = size;
 146        stream.next_out = out;
 147        stream.avail_out = maxsize;
 148        while (deflate(&stream, Z_FINISH) == Z_OK)
 149                ; /* nothing */
 150        deflateEnd(&stream);
 151
 152        free(in);
 153        return stream.total_out;
 154}
 155
 156/*
 157 * The per-object header is a pretty dense thing, which is
 158 *  - first byte: low four bits are "size", then three bits of "type",
 159 *    and the high bit is "size continues".
 160 *  - each byte afterwards: low seven bits are size continuation,
 161 *    with the high bit being "size continues"
 162 */
 163static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 164{
 165        int n = 1;
 166        unsigned char c;
 167
 168        if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 169                die("bad type %d", type);
 170
 171        c = (type << 4) | (size & 15);
 172        size >>= 4;
 173        while (size) {
 174                *hdr++ = c | 0x80;
 175                c = size & 0x7f;
 176                size >>= 7;
 177                n++;
 178        }
 179        *hdr = c;
 180        return n;
 181}
 182
 183/*
 184 * we are going to reuse the existing object data as is.  make
 185 * sure it is not corrupt.
 186 */
 187static int check_pack_inflate(struct packed_git *p,
 188                struct pack_window **w_curs,
 189                off_t offset,
 190                off_t len,
 191                unsigned long expect)
 192{
 193        z_stream stream;
 194        unsigned char fakebuf[4096], *in;
 195        int st;
 196
 197        memset(&stream, 0, sizeof(stream));
 198        git_inflate_init(&stream);
 199        do {
 200                in = use_pack(p, w_curs, offset, &stream.avail_in);
 201                stream.next_in = in;
 202                stream.next_out = fakebuf;
 203                stream.avail_out = sizeof(fakebuf);
 204                st = git_inflate(&stream, Z_FINISH);
 205                offset += stream.next_in - in;
 206        } while (st == Z_OK || st == Z_BUF_ERROR);
 207        git_inflate_end(&stream);
 208        return (st == Z_STREAM_END &&
 209                stream.total_out == expect &&
 210                stream.total_in == len) ? 0 : -1;
 211}
 212
 213static void copy_pack_data(struct sha1file *f,
 214                struct packed_git *p,
 215                struct pack_window **w_curs,
 216                off_t offset,
 217                off_t len)
 218{
 219        unsigned char *in;
 220        unsigned int avail;
 221
 222        while (len) {
 223                in = use_pack(p, w_curs, offset, &avail);
 224                if (avail > len)
 225                        avail = (unsigned int)len;
 226                sha1write(f, in, avail);
 227                offset += avail;
 228                len -= avail;
 229        }
 230}
 231
 232static unsigned long write_object(struct sha1file *f,
 233                                  struct object_entry *entry,
 234                                  off_t write_offset)
 235{
 236        unsigned long size, limit, datalen;
 237        void *buf;
 238        unsigned char header[10], dheader[10];
 239        unsigned hdrlen;
 240        enum object_type type;
 241        int usable_delta, to_reuse;
 242
 243        if (!pack_to_stdout)
 244                crc32_begin(f);
 245
 246        type = entry->type;
 247
 248        /* write limit if limited packsize and not first object */
 249        if (!pack_size_limit || !nr_written)
 250                limit = 0;
 251        else if (pack_size_limit <= write_offset)
 252                /*
 253                 * the earlier object did not fit the limit; avoid
 254                 * mistaking this with unlimited (i.e. limit = 0).
 255                 */
 256                limit = 1;
 257        else
 258                limit = pack_size_limit - write_offset;
 259
 260        if (!entry->delta)
 261                usable_delta = 0;       /* no delta */
 262        else if (!pack_size_limit)
 263               usable_delta = 1;        /* unlimited packfile */
 264        else if (entry->delta->idx.offset == (off_t)-1)
 265                usable_delta = 0;       /* base was written to another pack */
 266        else if (entry->delta->idx.offset)
 267                usable_delta = 1;       /* base already exists in this pack */
 268        else
 269                usable_delta = 0;       /* base could end up in another pack */
 270
 271        if (!reuse_object)
 272                to_reuse = 0;   /* explicit */
 273        else if (!entry->in_pack)
 274                to_reuse = 0;   /* can't reuse what we don't have */
 275        else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
 276                                /* check_object() decided it for us ... */
 277                to_reuse = usable_delta;
 278                                /* ... but pack split may override that */
 279        else if (type != entry->in_pack_type)
 280                to_reuse = 0;   /* pack has delta which is unusable */
 281        else if (entry->delta)
 282                to_reuse = 0;   /* we want to pack afresh */
 283        else
 284                to_reuse = 1;   /* we have it in-pack undeltified,
 285                                 * and we do not need to deltify it.
 286                                 */
 287
 288        if (!to_reuse) {
 289                no_reuse:
 290                if (!usable_delta) {
 291                        buf = read_sha1_file(entry->idx.sha1, &type, &size);
 292                        if (!buf)
 293                                die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 294                        /*
 295                         * make sure no cached delta data remains from a
 296                         * previous attempt before a pack split occurred.
 297                         */
 298                        free(entry->delta_data);
 299                        entry->delta_data = NULL;
 300                        entry->z_delta_size = 0;
 301                } else if (entry->delta_data) {
 302                        size = entry->delta_size;
 303                        buf = entry->delta_data;
 304                        entry->delta_data = NULL;
 305                        type = (allow_ofs_delta && entry->delta->idx.offset) ?
 306                                OBJ_OFS_DELTA : OBJ_REF_DELTA;
 307                } else {
 308                        buf = get_delta(entry);
 309                        size = entry->delta_size;
 310                        type = (allow_ofs_delta && entry->delta->idx.offset) ?
 311                                OBJ_OFS_DELTA : OBJ_REF_DELTA;
 312                }
 313
 314                if (entry->z_delta_size)
 315                        datalen = entry->z_delta_size;
 316                else
 317                        datalen = do_compress(&buf, size);
 318
 319                /*
 320                 * The object header is a byte of 'type' followed by zero or
 321                 * more bytes of length.
 322                 */
 323                hdrlen = encode_header(type, size, header);
 324
 325                if (type == OBJ_OFS_DELTA) {
 326                        /*
 327                         * Deltas with relative base contain an additional
 328                         * encoding of the relative offset for the delta
 329                         * base from this object's position in the pack.
 330                         */
 331                        off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 332                        unsigned pos = sizeof(dheader) - 1;
 333                        dheader[pos] = ofs & 127;
 334                        while (ofs >>= 7)
 335                                dheader[--pos] = 128 | (--ofs & 127);
 336                        if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 337                                free(buf);
 338                                return 0;
 339                        }
 340                        sha1write(f, header, hdrlen);
 341                        sha1write(f, dheader + pos, sizeof(dheader) - pos);
 342                        hdrlen += sizeof(dheader) - pos;
 343                } else if (type == OBJ_REF_DELTA) {
 344                        /*
 345                         * Deltas with a base reference contain
 346                         * an additional 20 bytes for the base sha1.
 347                         */
 348                        if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 349                                free(buf);
 350                                return 0;
 351                        }
 352                        sha1write(f, header, hdrlen);
 353                        sha1write(f, entry->delta->idx.sha1, 20);
 354                        hdrlen += 20;
 355                } else {
 356                        if (limit && hdrlen + datalen + 20 >= limit) {
 357                                free(buf);
 358                                return 0;
 359                        }
 360                        sha1write(f, header, hdrlen);
 361                }
 362                sha1write(f, buf, datalen);
 363                free(buf);
 364        }
 365        else {
 366                struct packed_git *p = entry->in_pack;
 367                struct pack_window *w_curs = NULL;
 368                struct revindex_entry *revidx;
 369                off_t offset;
 370
 371                if (entry->delta)
 372                        type = (allow_ofs_delta && entry->delta->idx.offset) ?
 373                                OBJ_OFS_DELTA : OBJ_REF_DELTA;
 374                hdrlen = encode_header(type, entry->size, header);
 375
 376                offset = entry->in_pack_offset;
 377                revidx = find_pack_revindex(p, offset);
 378                datalen = revidx[1].offset - offset;
 379                if (!pack_to_stdout && p->index_version > 1 &&
 380                    check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 381                        error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 382                        unuse_pack(&w_curs);
 383                        goto no_reuse;
 384                }
 385
 386                offset += entry->in_pack_header_size;
 387                datalen -= entry->in_pack_header_size;
 388                if (!pack_to_stdout && p->index_version == 1 &&
 389                    check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
 390                        error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 391                        unuse_pack(&w_curs);
 392                        goto no_reuse;
 393                }
 394
 395                if (type == OBJ_OFS_DELTA) {
 396                        off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 397                        unsigned pos = sizeof(dheader) - 1;
 398                        dheader[pos] = ofs & 127;
 399                        while (ofs >>= 7)
 400                                dheader[--pos] = 128 | (--ofs & 127);
 401                        if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 402                                unuse_pack(&w_curs);
 403                                return 0;
 404                        }
 405                        sha1write(f, header, hdrlen);
 406                        sha1write(f, dheader + pos, sizeof(dheader) - pos);
 407                        hdrlen += sizeof(dheader) - pos;
 408                        reused_delta++;
 409                } else if (type == OBJ_REF_DELTA) {
 410                        if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 411                                unuse_pack(&w_curs);
 412                                return 0;
 413                        }
 414                        sha1write(f, header, hdrlen);
 415                        sha1write(f, entry->delta->idx.sha1, 20);
 416                        hdrlen += 20;
 417                        reused_delta++;
 418                } else {
 419                        if (limit && hdrlen + datalen + 20 >= limit) {
 420                                unuse_pack(&w_curs);
 421                                return 0;
 422                        }
 423                        sha1write(f, header, hdrlen);
 424                }
 425                copy_pack_data(f, p, &w_curs, offset, datalen);
 426                unuse_pack(&w_curs);
 427                reused++;
 428        }
 429        if (usable_delta)
 430                written_delta++;
 431        written++;
 432        if (!pack_to_stdout)
 433                entry->idx.crc32 = crc32_end(f);
 434        return hdrlen + datalen;
 435}
 436
 437static int write_one(struct sha1file *f,
 438                               struct object_entry *e,
 439                               off_t *offset)
 440{
 441        unsigned long size;
 442
 443        /* offset is non zero if object is written already. */
 444        if (e->idx.offset || e->preferred_base)
 445                return 1;
 446
 447        /* if we are deltified, write out base object first. */
 448        if (e->delta && !write_one(f, e->delta, offset))
 449                return 0;
 450
 451        e->idx.offset = *offset;
 452        size = write_object(f, e, *offset);
 453        if (!size) {
 454                e->idx.offset = 0;
 455                return 0;
 456        }
 457        written_list[nr_written++] = &e->idx;
 458
 459        /* make sure off_t is sufficiently large not to wrap */
 460        if (*offset > *offset + size)
 461                die("pack too large for current definition of off_t");
 462        *offset += size;
 463        return 1;
 464}
 465
 466/* forward declaration for write_pack_file */
 467static int adjust_perm(const char *path, mode_t mode);
 468
 469static void write_pack_file(void)
 470{
 471        uint32_t i = 0, j;
 472        struct sha1file *f;
 473        off_t offset;
 474        struct pack_header hdr;
 475        uint32_t nr_remaining = nr_result;
 476        time_t last_mtime = 0;
 477
 478        if (progress > pack_to_stdout)
 479                progress_state = start_progress("Writing objects", nr_result);
 480        written_list = xmalloc(nr_objects * sizeof(*written_list));
 481
 482        do {
 483                unsigned char sha1[20];
 484                char *pack_tmp_name = NULL;
 485
 486                if (pack_to_stdout) {
 487                        f = sha1fd_throughput(1, "<stdout>", progress_state);
 488                } else {
 489                        char tmpname[PATH_MAX];
 490                        int fd;
 491                        fd = odb_mkstemp(tmpname, sizeof(tmpname),
 492                                         "pack/tmp_pack_XXXXXX");
 493                        pack_tmp_name = xstrdup(tmpname);
 494                        f = sha1fd(fd, pack_tmp_name);
 495                }
 496
 497                hdr.hdr_signature = htonl(PACK_SIGNATURE);
 498                hdr.hdr_version = htonl(PACK_VERSION);
 499                hdr.hdr_entries = htonl(nr_remaining);
 500                sha1write(f, &hdr, sizeof(hdr));
 501                offset = sizeof(hdr);
 502                nr_written = 0;
 503                for (; i < nr_objects; i++) {
 504                        if (!write_one(f, objects + i, &offset))
 505                                break;
 506                        display_progress(progress_state, written);
 507                }
 508
 509                /*
 510                 * Did we write the wrong # entries in the header?
 511                 * If so, rewrite it like in fast-import
 512                 */
 513                if (pack_to_stdout) {
 514                        sha1close(f, sha1, CSUM_CLOSE);
 515                } else if (nr_written == nr_remaining) {
 516                        sha1close(f, sha1, CSUM_FSYNC);
 517                } else {
 518                        int fd = sha1close(f, sha1, 0);
 519                        fixup_pack_header_footer(fd, sha1, pack_tmp_name,
 520                                                 nr_written, sha1, offset);
 521                        close(fd);
 522                }
 523
 524                if (!pack_to_stdout) {
 525                        mode_t mode = umask(0);
 526                        struct stat st;
 527                        char *idx_tmp_name, tmpname[PATH_MAX];
 528
 529                        umask(mode);
 530                        mode = 0444 & ~mode;
 531
 532                        idx_tmp_name = write_idx_file(NULL, written_list,
 533                                                      nr_written, sha1);
 534
 535                        snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 536                                 base_name, sha1_to_hex(sha1));
 537                        free_pack_by_name(tmpname);
 538                        if (adjust_perm(pack_tmp_name, mode))
 539                                die_errno("unable to make temporary pack file readable");
 540                        if (rename(pack_tmp_name, tmpname))
 541                                die_errno("unable to rename temporary pack file");
 542
 543                        /*
 544                         * Packs are runtime accessed in their mtime
 545                         * order since newer packs are more likely to contain
 546                         * younger objects.  So if we are creating multiple
 547                         * packs then we should modify the mtime of later ones
 548                         * to preserve this property.
 549                         */
 550                        if (stat(tmpname, &st) < 0) {
 551                                warning("failed to stat %s: %s",
 552                                        tmpname, strerror(errno));
 553                        } else if (!last_mtime) {
 554                                last_mtime = st.st_mtime;
 555                        } else {
 556                                struct utimbuf utb;
 557                                utb.actime = st.st_atime;
 558                                utb.modtime = --last_mtime;
 559                                if (utime(tmpname, &utb) < 0)
 560                                        warning("failed utime() on %s: %s",
 561                                                tmpname, strerror(errno));
 562                        }
 563
 564                        snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 565                                 base_name, sha1_to_hex(sha1));
 566                        if (adjust_perm(idx_tmp_name, mode))
 567                                die_errno("unable to make temporary index file readable");
 568                        if (rename(idx_tmp_name, tmpname))
 569                                die_errno("unable to rename temporary index file");
 570
 571                        free(idx_tmp_name);
 572                        free(pack_tmp_name);
 573                        puts(sha1_to_hex(sha1));
 574                }
 575
 576                /* mark written objects as written to previous pack */
 577                for (j = 0; j < nr_written; j++) {
 578                        written_list[j]->offset = (off_t)-1;
 579                }
 580                nr_remaining -= nr_written;
 581        } while (nr_remaining && i < nr_objects);
 582
 583        free(written_list);
 584        stop_progress(&progress_state);
 585        if (written != nr_result)
 586                die("wrote %"PRIu32" objects while expecting %"PRIu32,
 587                        written, nr_result);
 588        /*
 589         * We have scanned through [0 ... i).  Since we have written
 590         * the correct number of objects,  the remaining [i ... nr_objects)
 591         * items must be either already written (due to out-of-order delta base)
 592         * or a preferred base.  Count those which are neither and complain if any.
 593         */
 594        for (j = 0; i < nr_objects; i++) {
 595                struct object_entry *e = objects + i;
 596                j += !e->idx.offset && !e->preferred_base;
 597        }
 598        if (j)
 599                die("wrote %"PRIu32" objects as expected but %"PRIu32
 600                        " unwritten", written, j);
 601}
 602
 603static int locate_object_entry_hash(const unsigned char *sha1)
 604{
 605        int i;
 606        unsigned int ui;
 607        memcpy(&ui, sha1, sizeof(unsigned int));
 608        i = ui % object_ix_hashsz;
 609        while (0 < object_ix[i]) {
 610                if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 611                        return i;
 612                if (++i == object_ix_hashsz)
 613                        i = 0;
 614        }
 615        return -1 - i;
 616}
 617
 618static struct object_entry *locate_object_entry(const unsigned char *sha1)
 619{
 620        int i;
 621
 622        if (!object_ix_hashsz)
 623                return NULL;
 624
 625        i = locate_object_entry_hash(sha1);
 626        if (0 <= i)
 627                return &objects[object_ix[i]-1];
 628        return NULL;
 629}
 630
 631static void rehash_objects(void)
 632{
 633        uint32_t i;
 634        struct object_entry *oe;
 635
 636        object_ix_hashsz = nr_objects * 3;
 637        if (object_ix_hashsz < 1024)
 638                object_ix_hashsz = 1024;
 639        object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 640        memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 641        for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 642                int ix = locate_object_entry_hash(oe->idx.sha1);
 643                if (0 <= ix)
 644                        continue;
 645                ix = -1 - ix;
 646                object_ix[ix] = i + 1;
 647        }
 648}
 649
 650static unsigned name_hash(const char *name)
 651{
 652        unsigned c, hash = 0;
 653
 654        if (!name)
 655                return 0;
 656
 657        /*
 658         * This effectively just creates a sortable number from the
 659         * last sixteen non-whitespace characters. Last characters
 660         * count "most", so things that end in ".c" sort together.
 661         */
 662        while ((c = *name++) != 0) {
 663                if (isspace(c))
 664                        continue;
 665                hash = (hash >> 2) + (c << 24);
 666        }
 667        return hash;
 668}
 669
 670static void setup_delta_attr_check(struct git_attr_check *check)
 671{
 672        static struct git_attr *attr_delta;
 673
 674        if (!attr_delta)
 675                attr_delta = git_attr("delta", 5);
 676
 677        check[0].attr = attr_delta;
 678}
 679
 680static int no_try_delta(const char *path)
 681{
 682        struct git_attr_check check[1];
 683
 684        setup_delta_attr_check(check);
 685        if (git_checkattr(path, ARRAY_SIZE(check), check))
 686                return 0;
 687        if (ATTR_FALSE(check->value))
 688                return 1;
 689        return 0;
 690}
 691
 692static int add_object_entry(const unsigned char *sha1, enum object_type type,
 693                            const char *name, int exclude)
 694{
 695        struct object_entry *entry;
 696        struct packed_git *p, *found_pack = NULL;
 697        off_t found_offset = 0;
 698        int ix;
 699        unsigned hash = name_hash(name);
 700
 701        ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 702        if (ix >= 0) {
 703                if (exclude) {
 704                        entry = objects + object_ix[ix] - 1;
 705                        if (!entry->preferred_base)
 706                                nr_result--;
 707                        entry->preferred_base = 1;
 708                }
 709                return 0;
 710        }
 711
 712        if (!exclude && local && has_loose_object_nonlocal(sha1))
 713                return 0;
 714
 715        for (p = packed_git; p; p = p->next) {
 716                off_t offset = find_pack_entry_one(sha1, p);
 717                if (offset) {
 718                        if (!found_pack) {
 719                                found_offset = offset;
 720                                found_pack = p;
 721                        }
 722                        if (exclude)
 723                                break;
 724                        if (incremental)
 725                                return 0;
 726                        if (local && !p->pack_local)
 727                                return 0;
 728                        if (ignore_packed_keep && p->pack_local && p->pack_keep)
 729                                return 0;
 730                }
 731        }
 732
 733        if (nr_objects >= nr_alloc) {
 734                nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 735                objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 736        }
 737
 738        entry = objects + nr_objects++;
 739        memset(entry, 0, sizeof(*entry));
 740        hashcpy(entry->idx.sha1, sha1);
 741        entry->hash = hash;
 742        if (type)
 743                entry->type = type;
 744        if (exclude)
 745                entry->preferred_base = 1;
 746        else
 747                nr_result++;
 748        if (found_pack) {
 749                entry->in_pack = found_pack;
 750                entry->in_pack_offset = found_offset;
 751        }
 752
 753        if (object_ix_hashsz * 3 <= nr_objects * 4)
 754                rehash_objects();
 755        else
 756                object_ix[-1 - ix] = nr_objects;
 757
 758        display_progress(progress_state, nr_objects);
 759
 760        if (name && no_try_delta(name))
 761                entry->no_try_delta = 1;
 762
 763        return 1;
 764}
 765
 766struct pbase_tree_cache {
 767        unsigned char sha1[20];
 768        int ref;
 769        int temporary;
 770        void *tree_data;
 771        unsigned long tree_size;
 772};
 773
 774static struct pbase_tree_cache *(pbase_tree_cache[256]);
 775static int pbase_tree_cache_ix(const unsigned char *sha1)
 776{
 777        return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 778}
 779static int pbase_tree_cache_ix_incr(int ix)
 780{
 781        return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 782}
 783
 784static struct pbase_tree {
 785        struct pbase_tree *next;
 786        /* This is a phony "cache" entry; we are not
 787         * going to evict it nor find it through _get()
 788         * mechanism -- this is for the toplevel node that
 789         * would almost always change with any commit.
 790         */
 791        struct pbase_tree_cache pcache;
 792} *pbase_tree;
 793
 794static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 795{
 796        struct pbase_tree_cache *ent, *nent;
 797        void *data;
 798        unsigned long size;
 799        enum object_type type;
 800        int neigh;
 801        int my_ix = pbase_tree_cache_ix(sha1);
 802        int available_ix = -1;
 803
 804        /* pbase-tree-cache acts as a limited hashtable.
 805         * your object will be found at your index or within a few
 806         * slots after that slot if it is cached.
 807         */
 808        for (neigh = 0; neigh < 8; neigh++) {
 809                ent = pbase_tree_cache[my_ix];
 810                if (ent && !hashcmp(ent->sha1, sha1)) {
 811                        ent->ref++;
 812                        return ent;
 813                }
 814                else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 815                         ((0 <= available_ix) &&
 816                          (!ent && pbase_tree_cache[available_ix])))
 817                        available_ix = my_ix;
 818                if (!ent)
 819                        break;
 820                my_ix = pbase_tree_cache_ix_incr(my_ix);
 821        }
 822
 823        /* Did not find one.  Either we got a bogus request or
 824         * we need to read and perhaps cache.
 825         */
 826        data = read_sha1_file(sha1, &type, &size);
 827        if (!data)
 828                return NULL;
 829        if (type != OBJ_TREE) {
 830                free(data);
 831                return NULL;
 832        }
 833
 834        /* We need to either cache or return a throwaway copy */
 835
 836        if (available_ix < 0)
 837                ent = NULL;
 838        else {
 839                ent = pbase_tree_cache[available_ix];
 840                my_ix = available_ix;
 841        }
 842
 843        if (!ent) {
 844                nent = xmalloc(sizeof(*nent));
 845                nent->temporary = (available_ix < 0);
 846        }
 847        else {
 848                /* evict and reuse */
 849                free(ent->tree_data);
 850                nent = ent;
 851        }
 852        hashcpy(nent->sha1, sha1);
 853        nent->tree_data = data;
 854        nent->tree_size = size;
 855        nent->ref = 1;
 856        if (!nent->temporary)
 857                pbase_tree_cache[my_ix] = nent;
 858        return nent;
 859}
 860
 861static void pbase_tree_put(struct pbase_tree_cache *cache)
 862{
 863        if (!cache->temporary) {
 864                cache->ref--;
 865                return;
 866        }
 867        free(cache->tree_data);
 868        free(cache);
 869}
 870
 871static int name_cmp_len(const char *name)
 872{
 873        int i;
 874        for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 875                ;
 876        return i;
 877}
 878
 879static void add_pbase_object(struct tree_desc *tree,
 880                             const char *name,
 881                             int cmplen,
 882                             const char *fullname)
 883{
 884        struct name_entry entry;
 885        int cmp;
 886
 887        while (tree_entry(tree,&entry)) {
 888                if (S_ISGITLINK(entry.mode))
 889                        continue;
 890                cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 891                      memcmp(name, entry.path, cmplen);
 892                if (cmp > 0)
 893                        continue;
 894                if (cmp < 0)
 895                        return;
 896                if (name[cmplen] != '/') {
 897                        add_object_entry(entry.sha1,
 898                                         object_type(entry.mode),
 899                                         fullname, 1);
 900                        return;
 901                }
 902                if (S_ISDIR(entry.mode)) {
 903                        struct tree_desc sub;
 904                        struct pbase_tree_cache *tree;
 905                        const char *down = name+cmplen+1;
 906                        int downlen = name_cmp_len(down);
 907
 908                        tree = pbase_tree_get(entry.sha1);
 909                        if (!tree)
 910                                return;
 911                        init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 912
 913                        add_pbase_object(&sub, down, downlen, fullname);
 914                        pbase_tree_put(tree);
 915                }
 916        }
 917}
 918
 919static unsigned *done_pbase_paths;
 920static int done_pbase_paths_num;
 921static int done_pbase_paths_alloc;
 922static int done_pbase_path_pos(unsigned hash)
 923{
 924        int lo = 0;
 925        int hi = done_pbase_paths_num;
 926        while (lo < hi) {
 927                int mi = (hi + lo) / 2;
 928                if (done_pbase_paths[mi] == hash)
 929                        return mi;
 930                if (done_pbase_paths[mi] < hash)
 931                        hi = mi;
 932                else
 933                        lo = mi + 1;
 934        }
 935        return -lo-1;
 936}
 937
 938static int check_pbase_path(unsigned hash)
 939{
 940        int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 941        if (0 <= pos)
 942                return 1;
 943        pos = -pos - 1;
 944        if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 945                done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 946                done_pbase_paths = xrealloc(done_pbase_paths,
 947                                            done_pbase_paths_alloc *
 948                                            sizeof(unsigned));
 949        }
 950        done_pbase_paths_num++;
 951        if (pos < done_pbase_paths_num)
 952                memmove(done_pbase_paths + pos + 1,
 953                        done_pbase_paths + pos,
 954                        (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 955        done_pbase_paths[pos] = hash;
 956        return 0;
 957}
 958
 959static void add_preferred_base_object(const char *name)
 960{
 961        struct pbase_tree *it;
 962        int cmplen;
 963        unsigned hash = name_hash(name);
 964
 965        if (!num_preferred_base || check_pbase_path(hash))
 966                return;
 967
 968        cmplen = name_cmp_len(name);
 969        for (it = pbase_tree; it; it = it->next) {
 970                if (cmplen == 0) {
 971                        add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 972                }
 973                else {
 974                        struct tree_desc tree;
 975                        init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 976                        add_pbase_object(&tree, name, cmplen, name);
 977                }
 978        }
 979}
 980
 981static void add_preferred_base(unsigned char *sha1)
 982{
 983        struct pbase_tree *it;
 984        void *data;
 985        unsigned long size;
 986        unsigned char tree_sha1[20];
 987
 988        if (window <= num_preferred_base++)
 989                return;
 990
 991        data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 992        if (!data)
 993                return;
 994
 995        for (it = pbase_tree; it; it = it->next) {
 996                if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 997                        free(data);
 998                        return;
 999                }
1000        }
1001
1002        it = xcalloc(1, sizeof(*it));
1003        it->next = pbase_tree;
1004        pbase_tree = it;
1005
1006        hashcpy(it->pcache.sha1, tree_sha1);
1007        it->pcache.tree_data = data;
1008        it->pcache.tree_size = size;
1009}
1010
1011static void check_object(struct object_entry *entry)
1012{
1013        if (entry->in_pack) {
1014                struct packed_git *p = entry->in_pack;
1015                struct pack_window *w_curs = NULL;
1016                const unsigned char *base_ref = NULL;
1017                struct object_entry *base_entry;
1018                unsigned long used, used_0;
1019                unsigned int avail;
1020                off_t ofs;
1021                unsigned char *buf, c;
1022
1023                buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1024
1025                /*
1026                 * We want in_pack_type even if we do not reuse delta
1027                 * since non-delta representations could still be reused.
1028                 */
1029                used = unpack_object_header_buffer(buf, avail,
1030                                                   &entry->in_pack_type,
1031                                                   &entry->size);
1032                if (used == 0)
1033                        goto give_up;
1034
1035                /*
1036                 * Determine if this is a delta and if so whether we can
1037                 * reuse it or not.  Otherwise let's find out as cheaply as
1038                 * possible what the actual type and size for this object is.
1039                 */
1040                switch (entry->in_pack_type) {
1041                default:
1042                        /* Not a delta hence we've already got all we need. */
1043                        entry->type = entry->in_pack_type;
1044                        entry->in_pack_header_size = used;
1045                        if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1046                                goto give_up;
1047                        unuse_pack(&w_curs);
1048                        return;
1049                case OBJ_REF_DELTA:
1050                        if (reuse_delta && !entry->preferred_base)
1051                                base_ref = use_pack(p, &w_curs,
1052                                                entry->in_pack_offset + used, NULL);
1053                        entry->in_pack_header_size = used + 20;
1054                        break;
1055                case OBJ_OFS_DELTA:
1056                        buf = use_pack(p, &w_curs,
1057                                       entry->in_pack_offset + used, NULL);
1058                        used_0 = 0;
1059                        c = buf[used_0++];
1060                        ofs = c & 127;
1061                        while (c & 128) {
1062                                ofs += 1;
1063                                if (!ofs || MSB(ofs, 7)) {
1064                                        error("delta base offset overflow in pack for %s",
1065                                              sha1_to_hex(entry->idx.sha1));
1066                                        goto give_up;
1067                                }
1068                                c = buf[used_0++];
1069                                ofs = (ofs << 7) + (c & 127);
1070                        }
1071                        ofs = entry->in_pack_offset - ofs;
1072                        if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1073                                error("delta base offset out of bound for %s",
1074                                      sha1_to_hex(entry->idx.sha1));
1075                                goto give_up;
1076                        }
1077                        if (reuse_delta && !entry->preferred_base) {
1078                                struct revindex_entry *revidx;
1079                                revidx = find_pack_revindex(p, ofs);
1080                                if (!revidx)
1081                                        goto give_up;
1082                                base_ref = nth_packed_object_sha1(p, revidx->nr);
1083                        }
1084                        entry->in_pack_header_size = used + used_0;
1085                        break;
1086                }
1087
1088                if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1089                        /*
1090                         * If base_ref was set above that means we wish to
1091                         * reuse delta data, and we even found that base
1092                         * in the list of objects we want to pack. Goodie!
1093                         *
1094                         * Depth value does not matter - find_deltas() will
1095                         * never consider reused delta as the base object to
1096                         * deltify other objects against, in order to avoid
1097                         * circular deltas.
1098                         */
1099                        entry->type = entry->in_pack_type;
1100                        entry->delta = base_entry;
1101                        entry->delta_size = entry->size;
1102                        entry->delta_sibling = base_entry->delta_child;
1103                        base_entry->delta_child = entry;
1104                        unuse_pack(&w_curs);
1105                        return;
1106                }
1107
1108                if (entry->type) {
1109                        /*
1110                         * This must be a delta and we already know what the
1111                         * final object type is.  Let's extract the actual
1112                         * object size from the delta header.
1113                         */
1114                        entry->size = get_size_from_delta(p, &w_curs,
1115                                        entry->in_pack_offset + entry->in_pack_header_size);
1116                        if (entry->size == 0)
1117                                goto give_up;
1118                        unuse_pack(&w_curs);
1119                        return;
1120                }
1121
1122                /*
1123                 * No choice but to fall back to the recursive delta walk
1124                 * with sha1_object_info() to find about the object type
1125                 * at this point...
1126                 */
1127                give_up:
1128                unuse_pack(&w_curs);
1129        }
1130
1131        entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1132        /*
1133         * The error condition is checked in prepare_pack().  This is
1134         * to permit a missing preferred base object to be ignored
1135         * as a preferred base.  Doing so can result in a larger
1136         * pack file, but the transfer will still take place.
1137         */
1138}
1139
1140static int pack_offset_sort(const void *_a, const void *_b)
1141{
1142        const struct object_entry *a = *(struct object_entry **)_a;
1143        const struct object_entry *b = *(struct object_entry **)_b;
1144
1145        /* avoid filesystem trashing with loose objects */
1146        if (!a->in_pack && !b->in_pack)
1147                return hashcmp(a->idx.sha1, b->idx.sha1);
1148
1149        if (a->in_pack < b->in_pack)
1150                return -1;
1151        if (a->in_pack > b->in_pack)
1152                return 1;
1153        return a->in_pack_offset < b->in_pack_offset ? -1 :
1154                        (a->in_pack_offset > b->in_pack_offset);
1155}
1156
1157static void get_object_details(void)
1158{
1159        uint32_t i;
1160        struct object_entry **sorted_by_offset;
1161
1162        sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1163        for (i = 0; i < nr_objects; i++)
1164                sorted_by_offset[i] = objects + i;
1165        qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1166
1167        for (i = 0; i < nr_objects; i++)
1168                check_object(sorted_by_offset[i]);
1169
1170        free(sorted_by_offset);
1171}
1172
1173/*
1174 * We search for deltas in a list sorted by type, by filename hash, and then
1175 * by size, so that we see progressively smaller and smaller files.
1176 * That's because we prefer deltas to be from the bigger file
1177 * to the smaller -- deletes are potentially cheaper, but perhaps
1178 * more importantly, the bigger file is likely the more recent
1179 * one.  The deepest deltas are therefore the oldest objects which are
1180 * less susceptible to be accessed often.
1181 */
1182static int type_size_sort(const void *_a, const void *_b)
1183{
1184        const struct object_entry *a = *(struct object_entry **)_a;
1185        const struct object_entry *b = *(struct object_entry **)_b;
1186
1187        if (a->type > b->type)
1188                return -1;
1189        if (a->type < b->type)
1190                return 1;
1191        if (a->hash > b->hash)
1192                return -1;
1193        if (a->hash < b->hash)
1194                return 1;
1195        if (a->preferred_base > b->preferred_base)
1196                return -1;
1197        if (a->preferred_base < b->preferred_base)
1198                return 1;
1199        if (a->size > b->size)
1200                return -1;
1201        if (a->size < b->size)
1202                return 1;
1203        return a < b ? -1 : (a > b);  /* newest first */
1204}
1205
1206struct unpacked {
1207        struct object_entry *entry;
1208        void *data;
1209        struct delta_index *index;
1210        unsigned depth;
1211};
1212
1213static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1214                           unsigned long delta_size)
1215{
1216        if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1217                return 0;
1218
1219        if (delta_size < cache_max_small_delta_size)
1220                return 1;
1221
1222        /* cache delta, if objects are large enough compared to delta size */
1223        if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1224                return 1;
1225
1226        return 0;
1227}
1228
1229#ifdef THREADED_DELTA_SEARCH
1230
1231static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1232#define read_lock()             pthread_mutex_lock(&read_mutex)
1233#define read_unlock()           pthread_mutex_unlock(&read_mutex)
1234
1235static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1236#define cache_lock()            pthread_mutex_lock(&cache_mutex)
1237#define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1238
1239static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1240#define progress_lock()         pthread_mutex_lock(&progress_mutex)
1241#define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1242
1243#else
1244
1245#define read_lock()             (void)0
1246#define read_unlock()           (void)0
1247#define cache_lock()            (void)0
1248#define cache_unlock()          (void)0
1249#define progress_lock()         (void)0
1250#define progress_unlock()       (void)0
1251
1252#endif
1253
1254static int try_delta(struct unpacked *trg, struct unpacked *src,
1255                     unsigned max_depth, unsigned long *mem_usage)
1256{
1257        struct object_entry *trg_entry = trg->entry;
1258        struct object_entry *src_entry = src->entry;
1259        unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1260        unsigned ref_depth;
1261        enum object_type type;
1262        void *delta_buf;
1263
1264        /* Don't bother doing diffs between different types */
1265        if (trg_entry->type != src_entry->type)
1266                return -1;
1267
1268        /*
1269         * We do not bother to try a delta that we discarded
1270         * on an earlier try, but only when reusing delta data.
1271         */
1272        if (reuse_delta && trg_entry->in_pack &&
1273            trg_entry->in_pack == src_entry->in_pack &&
1274            trg_entry->in_pack_type != OBJ_REF_DELTA &&
1275            trg_entry->in_pack_type != OBJ_OFS_DELTA)
1276                return 0;
1277
1278        /* Let's not bust the allowed depth. */
1279        if (src->depth >= max_depth)
1280                return 0;
1281
1282        /* Now some size filtering heuristics. */
1283        trg_size = trg_entry->size;
1284        if (!trg_entry->delta) {
1285                max_size = trg_size/2 - 20;
1286                ref_depth = 1;
1287        } else {
1288                max_size = trg_entry->delta_size;
1289                ref_depth = trg->depth;
1290        }
1291        max_size = (uint64_t)max_size * (max_depth - src->depth) /
1292                                                (max_depth - ref_depth + 1);
1293        if (max_size == 0)
1294                return 0;
1295        src_size = src_entry->size;
1296        sizediff = src_size < trg_size ? trg_size - src_size : 0;
1297        if (sizediff >= max_size)
1298                return 0;
1299        if (trg_size < src_size / 32)
1300                return 0;
1301
1302        /* Load data if not already done */
1303        if (!trg->data) {
1304                read_lock();
1305                trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1306                read_unlock();
1307                if (!trg->data)
1308                        die("object %s cannot be read",
1309                            sha1_to_hex(trg_entry->idx.sha1));
1310                if (sz != trg_size)
1311                        die("object %s inconsistent object length (%lu vs %lu)",
1312                            sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1313                *mem_usage += sz;
1314        }
1315        if (!src->data) {
1316                read_lock();
1317                src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1318                read_unlock();
1319                if (!src->data)
1320                        die("object %s cannot be read",
1321                            sha1_to_hex(src_entry->idx.sha1));
1322                if (sz != src_size)
1323                        die("object %s inconsistent object length (%lu vs %lu)",
1324                            sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1325                *mem_usage += sz;
1326        }
1327        if (!src->index) {
1328                src->index = create_delta_index(src->data, src_size);
1329                if (!src->index) {
1330                        static int warned = 0;
1331                        if (!warned++)
1332                                warning("suboptimal pack - out of memory");
1333                        return 0;
1334                }
1335                *mem_usage += sizeof_delta_index(src->index);
1336        }
1337
1338        delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1339        if (!delta_buf)
1340                return 0;
1341
1342        if (trg_entry->delta) {
1343                /* Prefer only shallower same-sized deltas. */
1344                if (delta_size == trg_entry->delta_size &&
1345                    src->depth + 1 >= trg->depth) {
1346                        free(delta_buf);
1347                        return 0;
1348                }
1349        }
1350
1351        /*
1352         * Handle memory allocation outside of the cache
1353         * accounting lock.  Compiler will optimize the strangeness
1354         * away when THREADED_DELTA_SEARCH is not defined.
1355         */
1356        free(trg_entry->delta_data);
1357        cache_lock();
1358        if (trg_entry->delta_data) {
1359                delta_cache_size -= trg_entry->delta_size;
1360                trg_entry->delta_data = NULL;
1361        }
1362        if (delta_cacheable(src_size, trg_size, delta_size)) {
1363                delta_cache_size += delta_size;
1364                cache_unlock();
1365                trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1366        } else {
1367                cache_unlock();
1368                free(delta_buf);
1369        }
1370
1371        trg_entry->delta = src_entry;
1372        trg_entry->delta_size = delta_size;
1373        trg->depth = src->depth + 1;
1374
1375        return 1;
1376}
1377
1378static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1379{
1380        struct object_entry *child = me->delta_child;
1381        unsigned int m = n;
1382        while (child) {
1383                unsigned int c = check_delta_limit(child, n + 1);
1384                if (m < c)
1385                        m = c;
1386                child = child->delta_sibling;
1387        }
1388        return m;
1389}
1390
1391static unsigned long free_unpacked(struct unpacked *n)
1392{
1393        unsigned long freed_mem = sizeof_delta_index(n->index);
1394        free_delta_index(n->index);
1395        n->index = NULL;
1396        if (n->data) {
1397                freed_mem += n->entry->size;
1398                free(n->data);
1399                n->data = NULL;
1400        }
1401        n->entry = NULL;
1402        n->depth = 0;
1403        return freed_mem;
1404}
1405
1406static void find_deltas(struct object_entry **list, unsigned *list_size,
1407                        int window, int depth, unsigned *processed)
1408{
1409        uint32_t i, idx = 0, count = 0;
1410        struct unpacked *array;
1411        unsigned long mem_usage = 0;
1412
1413        array = xcalloc(window, sizeof(struct unpacked));
1414
1415        for (;;) {
1416                struct object_entry *entry;
1417                struct unpacked *n = array + idx;
1418                int j, max_depth, best_base = -1;
1419
1420                progress_lock();
1421                if (!*list_size) {
1422                        progress_unlock();
1423                        break;
1424                }
1425                entry = *list++;
1426                (*list_size)--;
1427                if (!entry->preferred_base) {
1428                        (*processed)++;
1429                        display_progress(progress_state, *processed);
1430                }
1431                progress_unlock();
1432
1433                mem_usage -= free_unpacked(n);
1434                n->entry = entry;
1435
1436                while (window_memory_limit &&
1437                       mem_usage > window_memory_limit &&
1438                       count > 1) {
1439                        uint32_t tail = (idx + window - count) % window;
1440                        mem_usage -= free_unpacked(array + tail);
1441                        count--;
1442                }
1443
1444                /* We do not compute delta to *create* objects we are not
1445                 * going to pack.
1446                 */
1447                if (entry->preferred_base)
1448                        goto next;
1449
1450                /*
1451                 * If the current object is at pack edge, take the depth the
1452                 * objects that depend on the current object into account
1453                 * otherwise they would become too deep.
1454                 */
1455                max_depth = depth;
1456                if (entry->delta_child) {
1457                        max_depth -= check_delta_limit(entry, 0);
1458                        if (max_depth <= 0)
1459                                goto next;
1460                }
1461
1462                j = window;
1463                while (--j > 0) {
1464                        int ret;
1465                        uint32_t other_idx = idx + j;
1466                        struct unpacked *m;
1467                        if (other_idx >= window)
1468                                other_idx -= window;
1469                        m = array + other_idx;
1470                        if (!m->entry)
1471                                break;
1472                        ret = try_delta(n, m, max_depth, &mem_usage);
1473                        if (ret < 0)
1474                                break;
1475                        else if (ret > 0)
1476                                best_base = other_idx;
1477                }
1478
1479                /*
1480                 * If we decided to cache the delta data, then it is best
1481                 * to compress it right away.  First because we have to do
1482                 * it anyway, and doing it here while we're threaded will
1483                 * save a lot of time in the non threaded write phase,
1484                 * as well as allow for caching more deltas within
1485                 * the same cache size limit.
1486                 * ...
1487                 * But only if not writing to stdout, since in that case
1488                 * the network is most likely throttling writes anyway,
1489                 * and therefore it is best to go to the write phase ASAP
1490                 * instead, as we can afford spending more time compressing
1491                 * between writes at that moment.
1492                 */
1493                if (entry->delta_data && !pack_to_stdout) {
1494                        entry->z_delta_size = do_compress(&entry->delta_data,
1495                                                          entry->delta_size);
1496                        cache_lock();
1497                        delta_cache_size -= entry->delta_size;
1498                        delta_cache_size += entry->z_delta_size;
1499                        cache_unlock();
1500                }
1501
1502                /* if we made n a delta, and if n is already at max
1503                 * depth, leaving it in the window is pointless.  we
1504                 * should evict it first.
1505                 */
1506                if (entry->delta && max_depth <= n->depth)
1507                        continue;
1508
1509                /*
1510                 * Move the best delta base up in the window, after the
1511                 * currently deltified object, to keep it longer.  It will
1512                 * be the first base object to be attempted next.
1513                 */
1514                if (entry->delta) {
1515                        struct unpacked swap = array[best_base];
1516                        int dist = (window + idx - best_base) % window;
1517                        int dst = best_base;
1518                        while (dist--) {
1519                                int src = (dst + 1) % window;
1520                                array[dst] = array[src];
1521                                dst = src;
1522                        }
1523                        array[dst] = swap;
1524                }
1525
1526                next:
1527                idx++;
1528                if (count + 1 < window)
1529                        count++;
1530                if (idx >= window)
1531                        idx = 0;
1532        }
1533
1534        for (i = 0; i < window; ++i) {
1535                free_delta_index(array[i].index);
1536                free(array[i].data);
1537        }
1538        free(array);
1539}
1540
1541#ifdef THREADED_DELTA_SEARCH
1542
1543/*
1544 * The main thread waits on the condition that (at least) one of the workers
1545 * has stopped working (which is indicated in the .working member of
1546 * struct thread_params).
1547 * When a work thread has completed its work, it sets .working to 0 and
1548 * signals the main thread and waits on the condition that .data_ready
1549 * becomes 1.
1550 */
1551
1552struct thread_params {
1553        pthread_t thread;
1554        struct object_entry **list;
1555        unsigned list_size;
1556        unsigned remaining;
1557        int window;
1558        int depth;
1559        int working;
1560        int data_ready;
1561        pthread_mutex_t mutex;
1562        pthread_cond_t cond;
1563        unsigned *processed;
1564};
1565
1566static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
1567
1568static void *threaded_find_deltas(void *arg)
1569{
1570        struct thread_params *me = arg;
1571
1572        while (me->remaining) {
1573                find_deltas(me->list, &me->remaining,
1574                            me->window, me->depth, me->processed);
1575
1576                progress_lock();
1577                me->working = 0;
1578                pthread_cond_signal(&progress_cond);
1579                progress_unlock();
1580
1581                /*
1582                 * We must not set ->data_ready before we wait on the
1583                 * condition because the main thread may have set it to 1
1584                 * before we get here. In order to be sure that new
1585                 * work is available if we see 1 in ->data_ready, it
1586                 * was initialized to 0 before this thread was spawned
1587                 * and we reset it to 0 right away.
1588                 */
1589                pthread_mutex_lock(&me->mutex);
1590                while (!me->data_ready)
1591                        pthread_cond_wait(&me->cond, &me->mutex);
1592                me->data_ready = 0;
1593                pthread_mutex_unlock(&me->mutex);
1594        }
1595        /* leave ->working 1 so that this doesn't get more work assigned */
1596        return NULL;
1597}
1598
1599static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1600                           int window, int depth, unsigned *processed)
1601{
1602        struct thread_params p[delta_search_threads];
1603        int i, ret, active_threads = 0;
1604
1605        if (delta_search_threads <= 1) {
1606                find_deltas(list, &list_size, window, depth, processed);
1607                return;
1608        }
1609        if (progress > pack_to_stdout)
1610                fprintf(stderr, "Delta compression using up to %d threads.\n",
1611                                delta_search_threads);
1612
1613        /* Partition the work amongst work threads. */
1614        for (i = 0; i < delta_search_threads; i++) {
1615                unsigned sub_size = list_size / (delta_search_threads - i);
1616
1617                /* don't use too small segments or no deltas will be found */
1618                if (sub_size < 2*window && i+1 < delta_search_threads)
1619                        sub_size = 0;
1620
1621                p[i].window = window;
1622                p[i].depth = depth;
1623                p[i].processed = processed;
1624                p[i].working = 1;
1625                p[i].data_ready = 0;
1626
1627                /* try to split chunks on "path" boundaries */
1628                while (sub_size && sub_size < list_size &&
1629                       list[sub_size]->hash &&
1630                       list[sub_size]->hash == list[sub_size-1]->hash)
1631                        sub_size++;
1632
1633                p[i].list = list;
1634                p[i].list_size = sub_size;
1635                p[i].remaining = sub_size;
1636
1637                list += sub_size;
1638                list_size -= sub_size;
1639        }
1640
1641        /* Start work threads. */
1642        for (i = 0; i < delta_search_threads; i++) {
1643                if (!p[i].list_size)
1644                        continue;
1645                pthread_mutex_init(&p[i].mutex, NULL);
1646                pthread_cond_init(&p[i].cond, NULL);
1647                ret = pthread_create(&p[i].thread, NULL,
1648                                     threaded_find_deltas, &p[i]);
1649                if (ret)
1650                        die("unable to create thread: %s", strerror(ret));
1651                active_threads++;
1652        }
1653
1654        /*
1655         * Now let's wait for work completion.  Each time a thread is done
1656         * with its work, we steal half of the remaining work from the
1657         * thread with the largest number of unprocessed objects and give
1658         * it to that newly idle thread.  This ensure good load balancing
1659         * until the remaining object list segments are simply too short
1660         * to be worth splitting anymore.
1661         */
1662        while (active_threads) {
1663                struct thread_params *target = NULL;
1664                struct thread_params *victim = NULL;
1665                unsigned sub_size = 0;
1666
1667                progress_lock();
1668                for (;;) {
1669                        for (i = 0; !target && i < delta_search_threads; i++)
1670                                if (!p[i].working)
1671                                        target = &p[i];
1672                        if (target)
1673                                break;
1674                        pthread_cond_wait(&progress_cond, &progress_mutex);
1675                }
1676
1677                for (i = 0; i < delta_search_threads; i++)
1678                        if (p[i].remaining > 2*window &&
1679                            (!victim || victim->remaining < p[i].remaining))
1680                                victim = &p[i];
1681                if (victim) {
1682                        sub_size = victim->remaining / 2;
1683                        list = victim->list + victim->list_size - sub_size;
1684                        while (sub_size && list[0]->hash &&
1685                               list[0]->hash == list[-1]->hash) {
1686                                list++;
1687                                sub_size--;
1688                        }
1689                        if (!sub_size) {
1690                                /*
1691                                 * It is possible for some "paths" to have
1692                                 * so many objects that no hash boundary
1693                                 * might be found.  Let's just steal the
1694                                 * exact half in that case.
1695                                 */
1696                                sub_size = victim->remaining / 2;
1697                                list -= sub_size;
1698                        }
1699                        target->list = list;
1700                        victim->list_size -= sub_size;
1701                        victim->remaining -= sub_size;
1702                }
1703                target->list_size = sub_size;
1704                target->remaining = sub_size;
1705                target->working = 1;
1706                progress_unlock();
1707
1708                pthread_mutex_lock(&target->mutex);
1709                target->data_ready = 1;
1710                pthread_cond_signal(&target->cond);
1711                pthread_mutex_unlock(&target->mutex);
1712
1713                if (!sub_size) {
1714                        pthread_join(target->thread, NULL);
1715                        pthread_cond_destroy(&target->cond);
1716                        pthread_mutex_destroy(&target->mutex);
1717                        active_threads--;
1718                }
1719        }
1720}
1721
1722#else
1723#define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1724#endif
1725
1726static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1727{
1728        unsigned char peeled[20];
1729
1730        if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1731            !peel_ref(path, peeled)        && /* peelable? */
1732            !is_null_sha1(peeled)          && /* annotated tag? */
1733            locate_object_entry(peeled))      /* object packed? */
1734                add_object_entry(sha1, OBJ_TAG, NULL, 0);
1735        return 0;
1736}
1737
1738static void prepare_pack(int window, int depth)
1739{
1740        struct object_entry **delta_list;
1741        uint32_t i, nr_deltas;
1742        unsigned n;
1743
1744        get_object_details();
1745
1746        /*
1747         * If we're locally repacking then we need to be doubly careful
1748         * from now on in order to make sure no stealth corruption gets
1749         * propagated to the new pack.  Clients receiving streamed packs
1750         * should validate everything they get anyway so no need to incur
1751         * the additional cost here in that case.
1752         */
1753        if (!pack_to_stdout)
1754                do_check_packed_object_crc = 1;
1755
1756        if (!nr_objects || !window || !depth)
1757                return;
1758
1759        delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1760        nr_deltas = n = 0;
1761
1762        for (i = 0; i < nr_objects; i++) {
1763                struct object_entry *entry = objects + i;
1764
1765                if (entry->delta)
1766                        /* This happens if we decided to reuse existing
1767                         * delta from a pack.  "reuse_delta &&" is implied.
1768                         */
1769                        continue;
1770
1771                if (entry->size < 50)
1772                        continue;
1773
1774                if (entry->no_try_delta)
1775                        continue;
1776
1777                if (!entry->preferred_base) {
1778                        nr_deltas++;
1779                        if (entry->type < 0)
1780                                die("unable to get type of object %s",
1781                                    sha1_to_hex(entry->idx.sha1));
1782                } else {
1783                        if (entry->type < 0) {
1784                                /*
1785                                 * This object is not found, but we
1786                                 * don't have to include it anyway.
1787                                 */
1788                                continue;
1789                        }
1790                }
1791
1792                delta_list[n++] = entry;
1793        }
1794
1795        if (nr_deltas && n > 1) {
1796                unsigned nr_done = 0;
1797                if (progress)
1798                        progress_state = start_progress("Compressing objects",
1799                                                        nr_deltas);
1800                qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1801                ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1802                stop_progress(&progress_state);
1803                if (nr_done != nr_deltas)
1804                        die("inconsistency with delta count");
1805        }
1806        free(delta_list);
1807}
1808
1809static int git_pack_config(const char *k, const char *v, void *cb)
1810{
1811        if(!strcmp(k, "pack.window")) {
1812                window = git_config_int(k, v);
1813                return 0;
1814        }
1815        if (!strcmp(k, "pack.windowmemory")) {
1816                window_memory_limit = git_config_ulong(k, v);
1817                return 0;
1818        }
1819        if (!strcmp(k, "pack.depth")) {
1820                depth = git_config_int(k, v);
1821                return 0;
1822        }
1823        if (!strcmp(k, "pack.compression")) {
1824                int level = git_config_int(k, v);
1825                if (level == -1)
1826                        level = Z_DEFAULT_COMPRESSION;
1827                else if (level < 0 || level > Z_BEST_COMPRESSION)
1828                        die("bad pack compression level %d", level);
1829                pack_compression_level = level;
1830                pack_compression_seen = 1;
1831                return 0;
1832        }
1833        if (!strcmp(k, "pack.deltacachesize")) {
1834                max_delta_cache_size = git_config_int(k, v);
1835                return 0;
1836        }
1837        if (!strcmp(k, "pack.deltacachelimit")) {
1838                cache_max_small_delta_size = git_config_int(k, v);
1839                return 0;
1840        }
1841        if (!strcmp(k, "pack.threads")) {
1842                delta_search_threads = git_config_int(k, v);
1843                if (delta_search_threads < 0)
1844                        die("invalid number of threads specified (%d)",
1845                            delta_search_threads);
1846#ifndef THREADED_DELTA_SEARCH
1847                if (delta_search_threads != 1)
1848                        warning("no threads support, ignoring %s", k);
1849#endif
1850                return 0;
1851        }
1852        if (!strcmp(k, "pack.indexversion")) {
1853                pack_idx_default_version = git_config_int(k, v);
1854                if (pack_idx_default_version > 2)
1855                        die("bad pack.indexversion=%"PRIu32,
1856                                pack_idx_default_version);
1857                return 0;
1858        }
1859        if (!strcmp(k, "pack.packsizelimit")) {
1860                pack_size_limit_cfg = git_config_ulong(k, v);
1861                return 0;
1862        }
1863        return git_default_config(k, v, cb);
1864}
1865
1866static void read_object_list_from_stdin(void)
1867{
1868        char line[40 + 1 + PATH_MAX + 2];
1869        unsigned char sha1[20];
1870
1871        for (;;) {
1872                if (!fgets(line, sizeof(line), stdin)) {
1873                        if (feof(stdin))
1874                                break;
1875                        if (!ferror(stdin))
1876                                die("fgets returned NULL, not EOF, not error!");
1877                        if (errno != EINTR)
1878                                die_errno("fgets");
1879                        clearerr(stdin);
1880                        continue;
1881                }
1882                if (line[0] == '-') {
1883                        if (get_sha1_hex(line+1, sha1))
1884                                die("expected edge sha1, got garbage:\n %s",
1885                                    line);
1886                        add_preferred_base(sha1);
1887                        continue;
1888                }
1889                if (get_sha1_hex(line, sha1))
1890                        die("expected sha1, got garbage:\n %s", line);
1891
1892                add_preferred_base_object(line+41);
1893                add_object_entry(sha1, 0, line+41, 0);
1894        }
1895}
1896
1897#define OBJECT_ADDED (1u<<20)
1898
1899static void show_commit(struct commit *commit, void *data)
1900{
1901        add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1902        commit->object.flags |= OBJECT_ADDED;
1903}
1904
1905static void show_object(struct object *obj, const struct name_path *path, const char *last)
1906{
1907        char *name = path_name(path, last);
1908
1909        add_preferred_base_object(name);
1910        add_object_entry(obj->sha1, obj->type, name, 0);
1911        obj->flags |= OBJECT_ADDED;
1912
1913        /*
1914         * We will have generated the hash from the name,
1915         * but not saved a pointer to it - we can free it
1916         */
1917        free((char *)name);
1918}
1919
1920static void show_edge(struct commit *commit)
1921{
1922        add_preferred_base(commit->object.sha1);
1923}
1924
1925struct in_pack_object {
1926        off_t offset;
1927        struct object *object;
1928};
1929
1930struct in_pack {
1931        int alloc;
1932        int nr;
1933        struct in_pack_object *array;
1934};
1935
1936static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1937{
1938        in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1939        in_pack->array[in_pack->nr].object = object;
1940        in_pack->nr++;
1941}
1942
1943/*
1944 * Compare the objects in the offset order, in order to emulate the
1945 * "git rev-list --objects" output that produced the pack originally.
1946 */
1947static int ofscmp(const void *a_, const void *b_)
1948{
1949        struct in_pack_object *a = (struct in_pack_object *)a_;
1950        struct in_pack_object *b = (struct in_pack_object *)b_;
1951
1952        if (a->offset < b->offset)
1953                return -1;
1954        else if (a->offset > b->offset)
1955                return 1;
1956        else
1957                return hashcmp(a->object->sha1, b->object->sha1);
1958}
1959
1960static void add_objects_in_unpacked_packs(struct rev_info *revs)
1961{
1962        struct packed_git *p;
1963        struct in_pack in_pack;
1964        uint32_t i;
1965
1966        memset(&in_pack, 0, sizeof(in_pack));
1967
1968        for (p = packed_git; p; p = p->next) {
1969                const unsigned char *sha1;
1970                struct object *o;
1971
1972                if (!p->pack_local || p->pack_keep)
1973                        continue;
1974                if (open_pack_index(p))
1975                        die("cannot open pack index");
1976
1977                ALLOC_GROW(in_pack.array,
1978                           in_pack.nr + p->num_objects,
1979                           in_pack.alloc);
1980
1981                for (i = 0; i < p->num_objects; i++) {
1982                        sha1 = nth_packed_object_sha1(p, i);
1983                        o = lookup_unknown_object(sha1);
1984                        if (!(o->flags & OBJECT_ADDED))
1985                                mark_in_pack_object(o, p, &in_pack);
1986                        o->flags |= OBJECT_ADDED;
1987                }
1988        }
1989
1990        if (in_pack.nr) {
1991                qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
1992                      ofscmp);
1993                for (i = 0; i < in_pack.nr; i++) {
1994                        struct object *o = in_pack.array[i].object;
1995                        add_object_entry(o->sha1, o->type, "", 0);
1996                }
1997        }
1998        free(in_pack.array);
1999}
2000
2001static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2002{
2003        static struct packed_git *last_found = (void *)1;
2004        struct packed_git *p;
2005
2006        p = (last_found != (void *)1) ? last_found : packed_git;
2007
2008        while (p) {
2009                if ((!p->pack_local || p->pack_keep) &&
2010                        find_pack_entry_one(sha1, p)) {
2011                        last_found = p;
2012                        return 1;
2013                }
2014                if (p == last_found)
2015                        p = packed_git;
2016                else
2017                        p = p->next;
2018                if (p == last_found)
2019                        p = p->next;
2020        }
2021        return 0;
2022}
2023
2024static void loosen_unused_packed_objects(struct rev_info *revs)
2025{
2026        struct packed_git *p;
2027        uint32_t i;
2028        const unsigned char *sha1;
2029
2030        for (p = packed_git; p; p = p->next) {
2031                if (!p->pack_local || p->pack_keep)
2032                        continue;
2033
2034                if (open_pack_index(p))
2035                        die("cannot open pack index");
2036
2037                for (i = 0; i < p->num_objects; i++) {
2038                        sha1 = nth_packed_object_sha1(p, i);
2039                        if (!locate_object_entry(sha1) &&
2040                                !has_sha1_pack_kept_or_nonlocal(sha1))
2041                                if (force_object_loose(sha1, p->mtime))
2042                                        die("unable to force loose object");
2043                }
2044        }
2045}
2046
2047static void get_object_list(int ac, const char **av)
2048{
2049        struct rev_info revs;
2050        char line[1000];
2051        int flags = 0;
2052
2053        init_revisions(&revs, NULL);
2054        save_commit_buffer = 0;
2055        setup_revisions(ac, av, &revs, NULL);
2056
2057        while (fgets(line, sizeof(line), stdin) != NULL) {
2058                int len = strlen(line);
2059                if (len && line[len - 1] == '\n')
2060                        line[--len] = 0;
2061                if (!len)
2062                        break;
2063                if (*line == '-') {
2064                        if (!strcmp(line, "--not")) {
2065                                flags ^= UNINTERESTING;
2066                                continue;
2067                        }
2068                        die("not a rev '%s'", line);
2069                }
2070                if (handle_revision_arg(line, &revs, flags, 1))
2071                        die("bad revision '%s'", line);
2072        }
2073
2074        if (prepare_revision_walk(&revs))
2075                die("revision walk setup failed");
2076        mark_edges_uninteresting(revs.commits, &revs, show_edge);
2077        traverse_commit_list(&revs, show_commit, show_object, NULL);
2078
2079        if (keep_unreachable)
2080                add_objects_in_unpacked_packs(&revs);
2081        if (unpack_unreachable)
2082                loosen_unused_packed_objects(&revs);
2083}
2084
2085static int adjust_perm(const char *path, mode_t mode)
2086{
2087        if (chmod(path, mode))
2088                return -1;
2089        return adjust_shared_perm(path);
2090}
2091
2092int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2093{
2094        int use_internal_rev_list = 0;
2095        int thin = 0;
2096        uint32_t i;
2097        const char **rp_av;
2098        int rp_ac_alloc = 64;
2099        int rp_ac;
2100
2101        rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2102
2103        rp_av[0] = "pack-objects";
2104        rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2105        rp_ac = 2;
2106
2107        git_config(git_pack_config, NULL);
2108        if (!pack_compression_seen && core_compression_seen)
2109                pack_compression_level = core_compression_level;
2110
2111        progress = isatty(2);
2112        for (i = 1; i < argc; i++) {
2113                const char *arg = argv[i];
2114
2115                if (*arg != '-')
2116                        break;
2117
2118                if (!strcmp("--non-empty", arg)) {
2119                        non_empty = 1;
2120                        continue;
2121                }
2122                if (!strcmp("--local", arg)) {
2123                        local = 1;
2124                        continue;
2125                }
2126                if (!strcmp("--incremental", arg)) {
2127                        incremental = 1;
2128                        continue;
2129                }
2130                if (!strcmp("--honor-pack-keep", arg)) {
2131                        ignore_packed_keep = 1;
2132                        continue;
2133                }
2134                if (!prefixcmp(arg, "--compression=")) {
2135                        char *end;
2136                        int level = strtoul(arg+14, &end, 0);
2137                        if (!arg[14] || *end)
2138                                usage(pack_usage);
2139                        if (level == -1)
2140                                level = Z_DEFAULT_COMPRESSION;
2141                        else if (level < 0 || level > Z_BEST_COMPRESSION)
2142                                die("bad pack compression level %d", level);
2143                        pack_compression_level = level;
2144                        continue;
2145                }
2146                if (!prefixcmp(arg, "--max-pack-size=")) {
2147                        char *end;
2148                        pack_size_limit_cfg = 0;
2149                        pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2150                        if (!arg[16] || *end)
2151                                usage(pack_usage);
2152                        continue;
2153                }
2154                if (!prefixcmp(arg, "--window=")) {
2155                        char *end;
2156                        window = strtoul(arg+9, &end, 0);
2157                        if (!arg[9] || *end)
2158                                usage(pack_usage);
2159                        continue;
2160                }
2161                if (!prefixcmp(arg, "--window-memory=")) {
2162                        if (!git_parse_ulong(arg+16, &window_memory_limit))
2163                                usage(pack_usage);
2164                        continue;
2165                }
2166                if (!prefixcmp(arg, "--threads=")) {
2167                        char *end;
2168                        delta_search_threads = strtoul(arg+10, &end, 0);
2169                        if (!arg[10] || *end || delta_search_threads < 0)
2170                                usage(pack_usage);
2171#ifndef THREADED_DELTA_SEARCH
2172                        if (delta_search_threads != 1)
2173                                warning("no threads support, "
2174                                        "ignoring %s", arg);
2175#endif
2176                        continue;
2177                }
2178                if (!prefixcmp(arg, "--depth=")) {
2179                        char *end;
2180                        depth = strtoul(arg+8, &end, 0);
2181                        if (!arg[8] || *end)
2182                                usage(pack_usage);
2183                        continue;
2184                }
2185                if (!strcmp("--progress", arg)) {
2186                        progress = 1;
2187                        continue;
2188                }
2189                if (!strcmp("--all-progress", arg)) {
2190                        progress = 2;
2191                        continue;
2192                }
2193                if (!strcmp("-q", arg)) {
2194                        progress = 0;
2195                        continue;
2196                }
2197                if (!strcmp("--no-reuse-delta", arg)) {
2198                        reuse_delta = 0;
2199                        continue;
2200                }
2201                if (!strcmp("--no-reuse-object", arg)) {
2202                        reuse_object = reuse_delta = 0;
2203                        continue;
2204                }
2205                if (!strcmp("--delta-base-offset", arg)) {
2206                        allow_ofs_delta = 1;
2207                        continue;
2208                }
2209                if (!strcmp("--stdout", arg)) {
2210                        pack_to_stdout = 1;
2211                        continue;
2212                }
2213                if (!strcmp("--revs", arg)) {
2214                        use_internal_rev_list = 1;
2215                        continue;
2216                }
2217                if (!strcmp("--keep-unreachable", arg)) {
2218                        keep_unreachable = 1;
2219                        continue;
2220                }
2221                if (!strcmp("--unpack-unreachable", arg)) {
2222                        unpack_unreachable = 1;
2223                        continue;
2224                }
2225                if (!strcmp("--include-tag", arg)) {
2226                        include_tag = 1;
2227                        continue;
2228                }
2229                if (!strcmp("--unpacked", arg) ||
2230                    !strcmp("--reflog", arg) ||
2231                    !strcmp("--all", arg)) {
2232                        use_internal_rev_list = 1;
2233                        if (rp_ac >= rp_ac_alloc - 1) {
2234                                rp_ac_alloc = alloc_nr(rp_ac_alloc);
2235                                rp_av = xrealloc(rp_av,
2236                                                 rp_ac_alloc * sizeof(*rp_av));
2237                        }
2238                        rp_av[rp_ac++] = arg;
2239                        continue;
2240                }
2241                if (!strcmp("--thin", arg)) {
2242                        use_internal_rev_list = 1;
2243                        thin = 1;
2244                        rp_av[1] = "--objects-edge";
2245                        continue;
2246                }
2247                if (!prefixcmp(arg, "--index-version=")) {
2248                        char *c;
2249                        pack_idx_default_version = strtoul(arg + 16, &c, 10);
2250                        if (pack_idx_default_version > 2)
2251                                die("bad %s", arg);
2252                        if (*c == ',')
2253                                pack_idx_off32_limit = strtoul(c+1, &c, 0);
2254                        if (*c || pack_idx_off32_limit & 0x80000000)
2255                                die("bad %s", arg);
2256                        continue;
2257                }
2258                if (!strcmp(arg, "--keep-true-parents")) {
2259                        grafts_replace_parents = 0;
2260                        continue;
2261                }
2262                usage(pack_usage);
2263        }
2264
2265        /* Traditionally "pack-objects [options] base extra" failed;
2266         * we would however want to take refs parameter that would
2267         * have been given to upstream rev-list ourselves, which means
2268         * we somehow want to say what the base name is.  So the
2269         * syntax would be:
2270         *
2271         * pack-objects [options] base <refs...>
2272         *
2273         * in other words, we would treat the first non-option as the
2274         * base_name and send everything else to the internal revision
2275         * walker.
2276         */
2277
2278        if (!pack_to_stdout)
2279                base_name = argv[i++];
2280
2281        if (pack_to_stdout != !base_name)
2282                usage(pack_usage);
2283
2284        if (!pack_to_stdout && !pack_size_limit)
2285                pack_size_limit = pack_size_limit_cfg;
2286
2287        if (pack_to_stdout && pack_size_limit)
2288                die("--max-pack-size cannot be used to build a pack for transfer.");
2289
2290        if (!pack_to_stdout && thin)
2291                die("--thin cannot be used to build an indexable pack.");
2292
2293        if (keep_unreachable && unpack_unreachable)
2294                die("--keep-unreachable and --unpack-unreachable are incompatible.");
2295
2296#ifdef THREADED_DELTA_SEARCH
2297        if (!delta_search_threads)      /* --threads=0 means autodetect */
2298                delta_search_threads = online_cpus();
2299#endif
2300
2301        prepare_packed_git();
2302
2303        if (progress)
2304                progress_state = start_progress("Counting objects", 0);
2305        if (!use_internal_rev_list)
2306                read_object_list_from_stdin();
2307        else {
2308                rp_av[rp_ac] = NULL;
2309                get_object_list(rp_ac, rp_av);
2310        }
2311        if (include_tag && nr_result)
2312                for_each_ref(add_ref_tag, NULL);
2313        stop_progress(&progress_state);
2314
2315        if (non_empty && !nr_result)
2316                return 0;
2317        if (nr_result)
2318                prepare_pack(window, depth);
2319        write_pack_file();
2320        if (progress)
2321                fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2322                        " reused %"PRIu32" (delta %"PRIu32")\n",
2323                        written, written_delta, reused, reused_delta);
2324        return 0;
2325}