git.oblomov.eu Git - git/blob - builtin-pack-objects.c

   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
  25 static const char pack_usage[] =
  26   "git 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]*]\n"
  31   "        [--reflog] [--stdout | base-name] [--include-tag]\n"
  32   "        [--keep-unreachable | --unpack-unreachable \n"
  33   "        [<ref-list | <object-list]";
  34
  35 struct 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  */
  65 static struct object_entry *objects;
  66 static struct pack_idx_entry **written_list;
  67 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
  68
  69 static int non_empty;
  70 static int reuse_delta = 1, reuse_object = 1;
  71 static int keep_unreachable, unpack_unreachable, include_tag;
  72 static int local;
  73 static int incremental;
  74 static int ignore_packed_keep;
  75 static int allow_ofs_delta;
  76 static const char *base_name;
  77 static int progress = 1;
  78 static int window = 10;
  79 static uint32_t pack_size_limit, pack_size_limit_cfg;
  80 static int depth = 50;
  81 static int delta_search_threads;
  82 static int pack_to_stdout;
  83 static int num_preferred_base;
  84 static struct progress *progress_state;
  85 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  86 static int pack_compression_seen;
  87
  88 static unsigned long delta_cache_size = 0;
  89 static unsigned long max_delta_cache_size = 256 * 1024 * 1024;
  90 static unsigned long cache_max_small_delta_size = 1000;
  91
  92 static 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  */
  99 static int *object_ix;
 100 static int object_ix_hashsz;
 101
 102 /*
 103  * stats
 104  */
 105 static uint32_t written, written_delta;
 106 static uint32_t reused, reused_delta;
 107
 108
 109 static 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
 130 static 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  */
 163 static 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  */
 187 static 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
 213 static 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
 232 static 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
 437 static 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 */
 467 static int adjust_perm(const char *path, mode_t mode);
 468
 469 static 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
 603 static 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
 618 static 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
 631 static 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
 650 static 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
 670 static 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
 680 static 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
 692 static 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
 766 struct 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
 774 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 775 static int pbase_tree_cache_ix(const unsigned char *sha1)
 776 {
 777         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 778 }
 779 static int pbase_tree_cache_ix_incr(int ix)
 780 {
 781         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 782 }
 783
 784 static 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
 794 static 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
 861 static 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
 871 static 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
 879 static 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
 919 static unsigned *done_pbase_paths;
 920 static int done_pbase_paths_num;
 921 static int done_pbase_paths_alloc;
 922 static 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
 938 static 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
 959 static 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
 981 static 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
1011 static void cleanup_preferred_base(void)
1012 {
1013         struct pbase_tree *it;
1014         unsigned i;
1015
1016         it = pbase_tree;
1017         pbase_tree = NULL;
1018         while (it) {
1019                 struct pbase_tree *this = it;
1020                 it = this->next;
1021                 free(this->pcache.tree_data);
1022                 free(this);
1023         }
1024
1025         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1026                 if (!pbase_tree_cache[i])
1027                         continue;
1028                 free(pbase_tree_cache[i]->tree_data);
1029                 free(pbase_tree_cache[i]);
1030                 pbase_tree_cache[i] = NULL;
1031         }
1032
1033         free(done_pbase_paths);
1034         done_pbase_paths = NULL;
1035         done_pbase_paths_num = done_pbase_paths_alloc = 0;
1036 }
1037
1038 static void check_object(struct object_entry *entry)
1039 {
1040         if (entry->in_pack) {
1041                 struct packed_git *p = entry->in_pack;
1042                 struct pack_window *w_curs = NULL;
1043                 const unsigned char *base_ref = NULL;
1044                 struct object_entry *base_entry;
1045                 unsigned long used, used_0;
1046                 unsigned int avail;
1047                 off_t ofs;
1048                 unsigned char *buf, c;
1049
1050                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1051
1052                 /*
1053                  * We want in_pack_type even if we do not reuse delta
1054                  * since non-delta representations could still be reused.
1055                  */
1056                 used = unpack_object_header_buffer(buf, avail,
1057                                                    &entry->in_pack_type,
1058                                                    &entry->size);
1059                 if (used == 0)
1060                         goto give_up;
1061
1062                 /*
1063                  * Determine if this is a delta and if so whether we can
1064                  * reuse it or not.  Otherwise let's find out as cheaply as
1065                  * possible what the actual type and size for this object is.
1066                  */
1067                 switch (entry->in_pack_type) {
1068                 default:
1069                         /* Not a delta hence we've already got all we need. */
1070                         entry->type = entry->in_pack_type;
1071                         entry->in_pack_header_size = used;
1072                         if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1073                                 goto give_up;
1074                         unuse_pack(&w_curs);
1075                         return;
1076                 case OBJ_REF_DELTA:
1077                         if (reuse_delta && !entry->preferred_base)
1078                                 base_ref = use_pack(p, &w_curs,
1079                                                 entry->in_pack_offset + used, NULL);
1080                         entry->in_pack_header_size = used + 20;
1081                         break;
1082                 case OBJ_OFS_DELTA:
1083                         buf = use_pack(p, &w_curs,
1084                                        entry->in_pack_offset + used, NULL);
1085                         used_0 = 0;
1086                         c = buf[used_0++];
1087                         ofs = c & 127;
1088                         while (c & 128) {
1089                                 ofs += 1;
1090                                 if (!ofs || MSB(ofs, 7)) {
1091                                         error("delta base offset overflow in pack for %s",
1092                                               sha1_to_hex(entry->idx.sha1));
1093                                         goto give_up;
1094                                 }
1095                                 c = buf[used_0++];
1096                                 ofs = (ofs << 7) + (c & 127);
1097                         }
1098                         ofs = entry->in_pack_offset - ofs;
1099                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1100                                 error("delta base offset out of bound for %s",
1101                                       sha1_to_hex(entry->idx.sha1));
1102                                 goto give_up;
1103                         }
1104                         if (reuse_delta && !entry->preferred_base) {
1105                                 struct revindex_entry *revidx;
1106                                 revidx = find_pack_revindex(p, ofs);
1107                                 if (!revidx)
1108                                         goto give_up;
1109                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1110                         }
1111                         entry->in_pack_header_size = used + used_0;
1112                         break;
1113                 }
1114
1115                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1116                         /*
1117                          * If base_ref was set above that means we wish to
1118                          * reuse delta data, and we even found that base
1119                          * in the list of objects we want to pack. Goodie!
1120                          *
1121                          * Depth value does not matter - find_deltas() will
1122                          * never consider reused delta as the base object to
1123                          * deltify other objects against, in order to avoid
1124                          * circular deltas.
1125                          */
1126                         entry->type = entry->in_pack_type;
1127                         entry->delta = base_entry;
1128                         entry->delta_size = entry->size;
1129                         entry->delta_sibling = base_entry->delta_child;
1130                         base_entry->delta_child = entry;
1131                         unuse_pack(&w_curs);
1132                         return;
1133                 }
1134
1135                 if (entry->type) {
1136                         /*
1137                          * This must be a delta and we already know what the
1138                          * final object type is.  Let's extract the actual
1139                          * object size from the delta header.
1140                          */
1141                         entry->size = get_size_from_delta(p, &w_curs,
1142                                         entry->in_pack_offset + entry->in_pack_header_size);
1143                         if (entry->size == 0)
1144                                 goto give_up;
1145                         unuse_pack(&w_curs);
1146                         return;
1147                 }
1148
1149                 /*
1150                  * No choice but to fall back to the recursive delta walk
1151                  * with sha1_object_info() to find about the object type
1152                  * at this point...
1153                  */
1154                 give_up:
1155                 unuse_pack(&w_curs);
1156         }
1157
1158         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1159         /*
1160          * The error condition is checked in prepare_pack().  This is
1161          * to permit a missing preferred base object to be ignored
1162          * as a preferred base.  Doing so can result in a larger
1163          * pack file, but the transfer will still take place.
1164          */
1165 }
1166
1167 static int pack_offset_sort(const void *_a, const void *_b)
1168 {
1169         const struct object_entry *a = *(struct object_entry **)_a;
1170         const struct object_entry *b = *(struct object_entry **)_b;
1171
1172         /* avoid filesystem trashing with loose objects */
1173         if (!a->in_pack && !b->in_pack)
1174                 return hashcmp(a->idx.sha1, b->idx.sha1);
1175
1176         if (a->in_pack < b->in_pack)
1177                 return -1;
1178         if (a->in_pack > b->in_pack)
1179                 return 1;
1180         return a->in_pack_offset < b->in_pack_offset ? -1 :
1181                         (a->in_pack_offset > b->in_pack_offset);
1182 }
1183
1184 static void get_object_details(void)
1185 {
1186         uint32_t i;
1187         struct object_entry **sorted_by_offset;
1188
1189         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1190         for (i = 0; i < nr_objects; i++)
1191                 sorted_by_offset[i] = objects + i;
1192         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1193
1194         for (i = 0; i < nr_objects; i++)
1195                 check_object(sorted_by_offset[i]);
1196
1197         free(sorted_by_offset);
1198 }
1199
1200 /*
1201  * We search for deltas in a list sorted by type, by filename hash, and then
1202  * by size, so that we see progressively smaller and smaller files.
1203  * That's because we prefer deltas to be from the bigger file
1204  * to the smaller -- deletes are potentially cheaper, but perhaps
1205  * more importantly, the bigger file is likely the more recent
1206  * one.  The deepest deltas are therefore the oldest objects which are
1207  * less susceptible to be accessed often.
1208  */
1209 static int type_size_sort(const void *_a, const void *_b)
1210 {
1211         const struct object_entry *a = *(struct object_entry **)_a;
1212         const struct object_entry *b = *(struct object_entry **)_b;
1213
1214         if (a->type > b->type)
1215                 return -1;
1216         if (a->type < b->type)
1217                 return 1;
1218         if (a->hash > b->hash)
1219                 return -1;
1220         if (a->hash < b->hash)
1221                 return 1;
1222         if (a->preferred_base > b->preferred_base)
1223                 return -1;
1224         if (a->preferred_base < b->preferred_base)
1225                 return 1;
1226         if (a->size > b->size)
1227                 return -1;
1228         if (a->size < b->size)
1229                 return 1;
1230         return a < b ? -1 : (a > b);  /* newest first */
1231 }
1232
1233 struct unpacked {
1234         struct object_entry *entry;
1235         void *data;
1236         struct delta_index *index;
1237         unsigned depth;
1238 };
1239
1240 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1241                            unsigned long delta_size)
1242 {
1243         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1244                 return 0;
1245
1246         if (delta_size < cache_max_small_delta_size)
1247                 return 1;
1248
1249         /* cache delta, if objects are large enough compared to delta size */
1250         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1251                 return 1;
1252
1253         return 0;
1254 }
1255
1256 #ifdef THREADED_DELTA_SEARCH
1257
1258 static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1259 #define read_lock()             pthread_mutex_lock(&read_mutex)
1260 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1261
1262 static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1263 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1264 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1265
1266 static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1267 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1268 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1269
1270 #else
1271
1272 #define read_lock()             (void)0
1273 #define read_unlock()           (void)0
1274 #define cache_lock()            (void)0
1275 #define cache_unlock()          (void)0
1276 #define progress_lock()         (void)0
1277 #define progress_unlock()       (void)0
1278
1279 #endif
1280
1281 static int try_delta(struct unpacked *trg, struct unpacked *src,
1282                      unsigned max_depth, unsigned long *mem_usage)
1283 {
1284         struct object_entry *trg_entry = trg->entry;
1285         struct object_entry *src_entry = src->entry;
1286         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1287         unsigned ref_depth;
1288         enum object_type type;
1289         void *delta_buf;
1290
1291         /* Don't bother doing diffs between different types */
1292         if (trg_entry->type != src_entry->type)
1293                 return -1;
1294
1295         /*
1296          * We do not bother to try a delta that we discarded
1297          * on an earlier try, but only when reusing delta data.
1298          */
1299         if (reuse_delta && trg_entry->in_pack &&
1300             trg_entry->in_pack == src_entry->in_pack &&
1301             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1302             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1303                 return 0;
1304
1305         /* Let's not bust the allowed depth. */
1306         if (src->depth >= max_depth)
1307                 return 0;
1308
1309         /* Now some size filtering heuristics. */
1310         trg_size = trg_entry->size;
1311         if (!trg_entry->delta) {
1312                 max_size = trg_size/2 - 20;
1313                 ref_depth = 1;
1314         } else {
1315                 max_size = trg_entry->delta_size;
1316                 ref_depth = trg->depth;
1317         }
1318         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1319                                                 (max_depth - ref_depth + 1);
1320         if (max_size == 0)
1321                 return 0;
1322         src_size = src_entry->size;
1323         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1324         if (sizediff >= max_size)
1325                 return 0;
1326         if (trg_size < src_size / 32)
1327                 return 0;
1328
1329         /* Load data if not already done */
1330         if (!trg->data) {
1331                 read_lock();
1332                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1333                 read_unlock();
1334                 if (!trg->data)
1335                         die("object %s cannot be read",
1336                             sha1_to_hex(trg_entry->idx.sha1));
1337                 if (sz != trg_size)
1338                         die("object %s inconsistent object length (%lu vs %lu)",
1339                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1340                 *mem_usage += sz;
1341         }
1342         if (!src->data) {
1343                 read_lock();
1344                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1345                 read_unlock();
1346                 if (!src->data)
1347                         die("object %s cannot be read",
1348                             sha1_to_hex(src_entry->idx.sha1));
1349                 if (sz != src_size)
1350                         die("object %s inconsistent object length (%lu vs %lu)",
1351                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1352                 *mem_usage += sz;
1353         }
1354         if (!src->index) {
1355                 src->index = create_delta_index(src->data, src_size);
1356                 if (!src->index) {
1357                         static int warned = 0;
1358                         if (!warned++)
1359                                 warning("suboptimal pack - out of memory");
1360                         return 0;
1361                 }
1362                 *mem_usage += sizeof_delta_index(src->index);
1363         }
1364
1365         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1366         if (!delta_buf)
1367                 return 0;
1368
1369         if (trg_entry->delta) {
1370                 /* Prefer only shallower same-sized deltas. */
1371                 if (delta_size == trg_entry->delta_size &&
1372                     src->depth + 1 >= trg->depth) {
1373                         free(delta_buf);
1374                         return 0;
1375                 }
1376         }
1377
1378         /*
1379          * Handle memory allocation outside of the cache
1380          * accounting lock.  Compiler will optimize the strangeness
1381          * away when THREADED_DELTA_SEARCH is not defined.
1382          */
1383         free(trg_entry->delta_data);
1384         cache_lock();
1385         if (trg_entry->delta_data) {
1386                 delta_cache_size -= trg_entry->delta_size;
1387                 trg_entry->delta_data = NULL;
1388         }
1389         if (delta_cacheable(src_size, trg_size, delta_size)) {
1390                 delta_cache_size += delta_size;
1391                 cache_unlock();
1392                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1393         } else {
1394                 cache_unlock();
1395                 free(delta_buf);
1396         }
1397
1398         trg_entry->delta = src_entry;
1399         trg_entry->delta_size = delta_size;
1400         trg->depth = src->depth + 1;
1401
1402         return 1;
1403 }
1404
1405 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1406 {
1407         struct object_entry *child = me->delta_child;
1408         unsigned int m = n;
1409         while (child) {
1410                 unsigned int c = check_delta_limit(child, n + 1);
1411                 if (m < c)
1412                         m = c;
1413                 child = child->delta_sibling;
1414         }
1415         return m;
1416 }
1417
1418 static unsigned long free_unpacked(struct unpacked *n)
1419 {
1420         unsigned long freed_mem = sizeof_delta_index(n->index);
1421         free_delta_index(n->index);
1422         n->index = NULL;
1423         if (n->data) {
1424                 freed_mem += n->entry->size;
1425                 free(n->data);
1426                 n->data = NULL;
1427         }
1428         n->entry = NULL;
1429         n->depth = 0;
1430         return freed_mem;
1431 }
1432
1433 static void find_deltas(struct object_entry **list, unsigned *list_size,
1434                         int window, int depth, unsigned *processed)
1435 {
1436         uint32_t i, idx = 0, count = 0;
1437         struct unpacked *array;
1438         unsigned long mem_usage = 0;
1439
1440         array = xcalloc(window, sizeof(struct unpacked));
1441
1442         for (;;) {
1443                 struct object_entry *entry;
1444                 struct unpacked *n = array + idx;
1445                 int j, max_depth, best_base = -1;
1446
1447                 progress_lock();
1448                 if (!*list_size) {
1449                         progress_unlock();
1450                         break;
1451                 }
1452                 entry = *list++;
1453                 (*list_size)--;
1454                 if (!entry->preferred_base) {
1455                         (*processed)++;
1456                         display_progress(progress_state, *processed);
1457                 }
1458                 progress_unlock();
1459
1460                 mem_usage -= free_unpacked(n);
1461                 n->entry = entry;
1462
1463                 while (window_memory_limit &&
1464                        mem_usage > window_memory_limit &&
1465                        count > 1) {
1466                         uint32_t tail = (idx + window - count) % window;
1467                         mem_usage -= free_unpacked(array + tail);
1468                         count--;
1469                 }
1470
1471                 /* We do not compute delta to *create* objects we are not
1472                  * going to pack.
1473                  */
1474                 if (entry->preferred_base)
1475                         goto next;
1476
1477                 /*
1478                  * If the current object is at pack edge, take the depth the
1479                  * objects that depend on the current object into account
1480                  * otherwise they would become too deep.
1481                  */
1482                 max_depth = depth;
1483                 if (entry->delta_child) {
1484                         max_depth -= check_delta_limit(entry, 0);
1485                         if (max_depth <= 0)
1486                                 goto next;
1487                 }
1488
1489                 j = window;
1490                 while (--j > 0) {
1491                         int ret;
1492                         uint32_t other_idx = idx + j;
1493                         struct unpacked *m;
1494                         if (other_idx >= window)
1495                                 other_idx -= window;
1496                         m = array + other_idx;
1497                         if (!m->entry)
1498                                 break;
1499                         ret = try_delta(n, m, max_depth, &mem_usage);
1500                         if (ret < 0)
1501                                 break;
1502                         else if (ret > 0)
1503                                 best_base = other_idx;
1504                 }
1505
1506                 /*
1507                  * If we decided to cache the delta data, then it is best
1508                  * to compress it right away.  First because we have to do
1509                  * it anyway, and doing it here while we're threaded will
1510                  * save a lot of time in the non threaded write phase,
1511                  * as well as allow for caching more deltas within
1512                  * the same cache size limit.
1513                  * ...
1514                  * But only if not writing to stdout, since in that case
1515                  * the network is most likely throttling writes anyway,
1516                  * and therefore it is best to go to the write phase ASAP
1517                  * instead, as we can afford spending more time compressing
1518                  * between writes at that moment.
1519                  */
1520                 if (entry->delta_data && !pack_to_stdout) {
1521                         entry->z_delta_size = do_compress(&entry->delta_data,
1522                                                           entry->delta_size);
1523                         cache_lock();
1524                         delta_cache_size -= entry->delta_size;
1525                         delta_cache_size += entry->z_delta_size;
1526                         cache_unlock();
1527                 }
1528
1529                 /* if we made n a delta, and if n is already at max
1530                  * depth, leaving it in the window is pointless.  we
1531                  * should evict it first.
1532                  */
1533                 if (entry->delta && max_depth <= n->depth)
1534                         continue;
1535
1536                 /*
1537                  * Move the best delta base up in the window, after the
1538                  * currently deltified object, to keep it longer.  It will
1539                  * be the first base object to be attempted next.
1540                  */
1541                 if (entry->delta) {
1542                         struct unpacked swap = array[best_base];
1543                         int dist = (window + idx - best_base) % window;
1544                         int dst = best_base;
1545                         while (dist--) {
1546                                 int src = (dst + 1) % window;
1547                                 array[dst] = array[src];
1548                                 dst = src;
1549                         }
1550                         array[dst] = swap;
1551                 }
1552
1553                 next:
1554                 idx++;
1555                 if (count + 1 < window)
1556                         count++;
1557                 if (idx >= window)
1558                         idx = 0;
1559         }
1560
1561         for (i = 0; i < window; ++i) {
1562                 free_delta_index(array[i].index);
1563                 free(array[i].data);
1564         }
1565         free(array);
1566 }
1567
1568 #ifdef THREADED_DELTA_SEARCH
1569
1570 /*
1571  * The main thread waits on the condition that (at least) one of the workers
1572  * has stopped working (which is indicated in the .working member of
1573  * struct thread_params).
1574  * When a work thread has completed its work, it sets .working to 0 and
1575  * signals the main thread and waits on the condition that .data_ready
1576  * becomes 1.
1577  */
1578
1579 struct thread_params {
1580         pthread_t thread;
1581         struct object_entry **list;
1582         unsigned list_size;
1583         unsigned remaining;
1584         int window;
1585         int depth;
1586         int working;
1587         int data_ready;
1588         pthread_mutex_t mutex;
1589         pthread_cond_t cond;
1590         unsigned *processed;
1591 };
1592
1593 static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
1594
1595 static void *threaded_find_deltas(void *arg)
1596 {
1597         struct thread_params *me = arg;
1598
1599         while (me->remaining) {
1600                 find_deltas(me->list, &me->remaining,
1601                             me->window, me->depth, me->processed);
1602
1603                 progress_lock();
1604                 me->working = 0;
1605                 pthread_cond_signal(&progress_cond);
1606                 progress_unlock();
1607
1608                 /*
1609                  * We must not set ->data_ready before we wait on the
1610                  * condition because the main thread may have set it to 1
1611                  * before we get here. In order to be sure that new
1612                  * work is available if we see 1 in ->data_ready, it
1613                  * was initialized to 0 before this thread was spawned
1614                  * and we reset it to 0 right away.
1615                  */
1616                 pthread_mutex_lock(&me->mutex);
1617                 while (!me->data_ready)
1618                         pthread_cond_wait(&me->cond, &me->mutex);
1619                 me->data_ready = 0;
1620                 pthread_mutex_unlock(&me->mutex);
1621         }
1622         /* leave ->working 1 so that this doesn't get more work assigned */
1623         return NULL;
1624 }
1625
1626 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1627                            int window, int depth, unsigned *processed)
1628 {
1629         struct thread_params *p;
1630         int i, ret, active_threads = 0;
1631
1632         if (delta_search_threads <= 1) {
1633                 find_deltas(list, &list_size, window, depth, processed);
1634                 return;
1635         }
1636         if (progress > pack_to_stdout)
1637                 fprintf(stderr, "Delta compression using up to %d threads.\n",
1638                                 delta_search_threads);
1639         p = xcalloc(delta_search_threads, sizeof(*p));
1640
1641         /* Partition the work amongst work threads. */
1642         for (i = 0; i < delta_search_threads; i++) {
1643                 unsigned sub_size = list_size / (delta_search_threads - i);
1644
1645                 /* don't use too small segments or no deltas will be found */
1646                 if (sub_size < 2*window && i+1 < delta_search_threads)
1647                         sub_size = 0;
1648
1649                 p[i].window = window;
1650                 p[i].depth = depth;
1651                 p[i].processed = processed;
1652                 p[i].working = 1;
1653                 p[i].data_ready = 0;
1654
1655                 /* try to split chunks on "path" boundaries */
1656                 while (sub_size && sub_size < list_size &&
1657                        list[sub_size]->hash &&
1658                        list[sub_size]->hash == list[sub_size-1]->hash)
1659                         sub_size++;
1660
1661                 p[i].list = list;
1662                 p[i].list_size = sub_size;
1663                 p[i].remaining = sub_size;
1664
1665                 list += sub_size;
1666                 list_size -= sub_size;
1667         }
1668
1669         /* Start work threads. */
1670         for (i = 0; i < delta_search_threads; i++) {
1671                 if (!p[i].list_size)
1672                         continue;
1673                 pthread_mutex_init(&p[i].mutex, NULL);
1674                 pthread_cond_init(&p[i].cond, NULL);
1675                 ret = pthread_create(&p[i].thread, NULL,
1676                                      threaded_find_deltas, &p[i]);
1677                 if (ret)
1678                         die("unable to create thread: %s", strerror(ret));
1679                 active_threads++;
1680         }
1681
1682         /*
1683          * Now let's wait for work completion.  Each time a thread is done
1684          * with its work, we steal half of the remaining work from the
1685          * thread with the largest number of unprocessed objects and give
1686          * it to that newly idle thread.  This ensure good load balancing
1687          * until the remaining object list segments are simply too short
1688          * to be worth splitting anymore.
1689          */
1690         while (active_threads) {
1691                 struct thread_params *target = NULL;
1692                 struct thread_params *victim = NULL;
1693                 unsigned sub_size = 0;
1694
1695                 progress_lock();
1696                 for (;;) {
1697                         for (i = 0; !target && i < delta_search_threads; i++)
1698                                 if (!p[i].working)
1699                                         target = &p[i];
1700                         if (target)
1701                                 break;
1702                         pthread_cond_wait(&progress_cond, &progress_mutex);
1703                 }
1704
1705                 for (i = 0; i < delta_search_threads; i++)
1706                         if (p[i].remaining > 2*window &&
1707                             (!victim || victim->remaining < p[i].remaining))
1708                                 victim = &p[i];
1709                 if (victim) {
1710                         sub_size = victim->remaining / 2;
1711                         list = victim->list + victim->list_size - sub_size;
1712                         while (sub_size && list[0]->hash &&
1713                                list[0]->hash == list[-1]->hash) {
1714                                 list++;
1715                                 sub_size--;
1716                         }
1717                         if (!sub_size) {
1718                                 /*
1719                                  * It is possible for some "paths" to have
1720                                  * so many objects that no hash boundary
1721                                  * might be found.  Let's just steal the
1722                                  * exact half in that case.
1723                                  */
1724                                 sub_size = victim->remaining / 2;
1725                                 list -= sub_size;
1726                         }
1727                         target->list = list;
1728                         victim->list_size -= sub_size;
1729                         victim->remaining -= sub_size;
1730                 }
1731                 target->list_size = sub_size;
1732                 target->remaining = sub_size;
1733                 target->working = 1;
1734                 progress_unlock();
1735
1736                 pthread_mutex_lock(&target->mutex);
1737                 target->data_ready = 1;
1738                 pthread_cond_signal(&target->cond);
1739                 pthread_mutex_unlock(&target->mutex);
1740
1741                 if (!sub_size) {
1742                         pthread_join(target->thread, NULL);
1743                         pthread_cond_destroy(&target->cond);
1744                         pthread_mutex_destroy(&target->mutex);
1745                         active_threads--;
1746                 }
1747         }
1748         free(p);
1749 }
1750
1751 #else
1752 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1753 #endif
1754
1755 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1756 {
1757         unsigned char peeled[20];
1758
1759         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1760             !peel_ref(path, peeled)        && /* peelable? */
1761             !is_null_sha1(peeled)          && /* annotated tag? */
1762             locate_object_entry(peeled))      /* object packed? */
1763                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1764         return 0;
1765 }
1766
1767 static void prepare_pack(int window, int depth)
1768 {
1769         struct object_entry **delta_list;
1770         uint32_t i, nr_deltas;
1771         unsigned n;
1772
1773         get_object_details();
1774
1775         /*
1776          * If we're locally repacking then we need to be doubly careful
1777          * from now on in order to make sure no stealth corruption gets
1778          * propagated to the new pack.  Clients receiving streamed packs
1779          * should validate everything they get anyway so no need to incur
1780          * the additional cost here in that case.
1781          */
1782         if (!pack_to_stdout)
1783                 do_check_packed_object_crc = 1;
1784
1785         if (!nr_objects || !window || !depth)
1786                 return;
1787
1788         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1789         nr_deltas = n = 0;
1790
1791         for (i = 0; i < nr_objects; i++) {
1792                 struct object_entry *entry = objects + i;
1793
1794                 if (entry->delta)
1795                         /* This happens if we decided to reuse existing
1796                          * delta from a pack.  "reuse_delta &&" is implied.
1797                          */
1798                         continue;
1799
1800                 if (entry->size < 50)
1801                         continue;
1802
1803                 if (entry->no_try_delta)
1804                         continue;
1805
1806                 if (!entry->preferred_base) {
1807                         nr_deltas++;
1808                         if (entry->type < 0)
1809                                 die("unable to get type of object %s",
1810                                     sha1_to_hex(entry->idx.sha1));
1811                 } else {
1812                         if (entry->type < 0) {
1813                                 /*
1814                                  * This object is not found, but we
1815                                  * don't have to include it anyway.
1816                                  */
1817                                 continue;
1818                         }
1819                 }
1820
1821                 delta_list[n++] = entry;
1822         }
1823
1824         if (nr_deltas && n > 1) {
1825                 unsigned nr_done = 0;
1826                 if (progress)
1827                         progress_state = start_progress("Compressing objects",
1828                                                         nr_deltas);
1829                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1830                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1831                 stop_progress(&progress_state);
1832                 if (nr_done != nr_deltas)
1833                         die("inconsistency with delta count");
1834         }
1835         free(delta_list);
1836 }
1837
1838 static int git_pack_config(const char *k, const char *v, void *cb)
1839 {
1840         if (!strcmp(k, "pack.window")) {
1841                 window = git_config_int(k, v);
1842                 return 0;
1843         }
1844         if (!strcmp(k, "pack.windowmemory")) {
1845                 window_memory_limit = git_config_ulong(k, v);
1846                 return 0;
1847         }
1848         if (!strcmp(k, "pack.depth")) {
1849                 depth = git_config_int(k, v);
1850                 return 0;
1851         }
1852         if (!strcmp(k, "pack.compression")) {
1853                 int level = git_config_int(k, v);
1854                 if (level == -1)
1855                         level = Z_DEFAULT_COMPRESSION;
1856                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1857                         die("bad pack compression level %d", level);
1858                 pack_compression_level = level;
1859                 pack_compression_seen = 1;
1860                 return 0;
1861         }
1862         if (!strcmp(k, "pack.deltacachesize")) {
1863                 max_delta_cache_size = git_config_int(k, v);
1864                 return 0;
1865         }
1866         if (!strcmp(k, "pack.deltacachelimit")) {
1867                 cache_max_small_delta_size = git_config_int(k, v);
1868                 return 0;
1869         }
1870         if (!strcmp(k, "pack.threads")) {
1871                 delta_search_threads = git_config_int(k, v);
1872                 if (delta_search_threads < 0)
1873                         die("invalid number of threads specified (%d)",
1874                             delta_search_threads);
1875 #ifndef THREADED_DELTA_SEARCH
1876                 if (delta_search_threads != 1)
1877                         warning("no threads support, ignoring %s", k);
1878 #endif
1879                 return 0;
1880         }
1881         if (!strcmp(k, "pack.indexversion")) {
1882                 pack_idx_default_version = git_config_int(k, v);
1883                 if (pack_idx_default_version > 2)
1884                         die("bad pack.indexversion=%"PRIu32,
1885                                 pack_idx_default_version);
1886                 return 0;
1887         }
1888         if (!strcmp(k, "pack.packsizelimit")) {
1889                 pack_size_limit_cfg = git_config_ulong(k, v);
1890                 return 0;
1891         }
1892         return git_default_config(k, v, cb);
1893 }
1894
1895 static void read_object_list_from_stdin(void)
1896 {
1897         char line[40 + 1 + PATH_MAX + 2];
1898         unsigned char sha1[20];
1899
1900         for (;;) {
1901                 if (!fgets(line, sizeof(line), stdin)) {
1902                         if (feof(stdin))
1903                                 break;
1904                         if (!ferror(stdin))
1905                                 die("fgets returned NULL, not EOF, not error!");
1906                         if (errno != EINTR)
1907                                 die_errno("fgets");
1908                         clearerr(stdin);
1909                         continue;
1910                 }
1911                 if (line[0] == '-') {
1912                         if (get_sha1_hex(line+1, sha1))
1913                                 die("expected edge sha1, got garbage:\n %s",
1914                                     line);
1915                         add_preferred_base(sha1);
1916                         continue;
1917                 }
1918                 if (get_sha1_hex(line, sha1))
1919                         die("expected sha1, got garbage:\n %s", line);
1920
1921                 add_preferred_base_object(line+41);
1922                 add_object_entry(sha1, 0, line+41, 0);
1923         }
1924 }
1925
1926 #define OBJECT_ADDED (1u<<20)
1927
1928 static void show_commit(struct commit *commit, void *data)
1929 {
1930         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1931         commit->object.flags |= OBJECT_ADDED;
1932 }
1933
1934 static void show_object(struct object *obj, const struct name_path *path, const char *last)
1935 {
1936         char *name = path_name(path, last);
1937
1938         add_preferred_base_object(name);
1939         add_object_entry(obj->sha1, obj->type, name, 0);
1940         obj->flags |= OBJECT_ADDED;
1941
1942         /*
1943          * We will have generated the hash from the name,
1944          * but not saved a pointer to it - we can free it
1945          */
1946         free((char *)name);
1947 }
1948
1949 static void show_edge(struct commit *commit)
1950 {
1951         add_preferred_base(commit->object.sha1);
1952 }
1953
1954 struct in_pack_object {
1955         off_t offset;
1956         struct object *object;
1957 };
1958
1959 struct in_pack {
1960         int alloc;
1961         int nr;
1962         struct in_pack_object *array;
1963 };
1964
1965 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1966 {
1967         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1968         in_pack->array[in_pack->nr].object = object;
1969         in_pack->nr++;
1970 }
1971
1972 /*
1973  * Compare the objects in the offset order, in order to emulate the
1974  * "git rev-list --objects" output that produced the pack originally.
1975  */
1976 static int ofscmp(const void *a_, const void *b_)
1977 {
1978         struct in_pack_object *a = (struct in_pack_object *)a_;
1979         struct in_pack_object *b = (struct in_pack_object *)b_;
1980
1981         if (a->offset < b->offset)
1982                 return -1;
1983         else if (a->offset > b->offset)
1984                 return 1;
1985         else
1986                 return hashcmp(a->object->sha1, b->object->sha1);
1987 }
1988
1989 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1990 {
1991         struct packed_git *p;
1992         struct in_pack in_pack;
1993         uint32_t i;
1994
1995         memset(&in_pack, 0, sizeof(in_pack));
1996
1997         for (p = packed_git; p; p = p->next) {
1998                 const unsigned char *sha1;
1999                 struct object *o;
2000
2001                 if (!p->pack_local || p->pack_keep)
2002                         continue;
2003                 if (open_pack_index(p))
2004                         die("cannot open pack index");
2005
2006                 ALLOC_GROW(in_pack.array,
2007                            in_pack.nr + p->num_objects,
2008                            in_pack.alloc);
2009
2010                 for (i = 0; i < p->num_objects; i++) {
2011                         sha1 = nth_packed_object_sha1(p, i);
2012                         o = lookup_unknown_object(sha1);
2013                         if (!(o->flags & OBJECT_ADDED))
2014                                 mark_in_pack_object(o, p, &in_pack);
2015                         o->flags |= OBJECT_ADDED;
2016                 }
2017         }
2018
2019         if (in_pack.nr) {
2020                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
2021                       ofscmp);
2022                 for (i = 0; i < in_pack.nr; i++) {
2023                         struct object *o = in_pack.array[i].object;
2024                         add_object_entry(o->sha1, o->type, "", 0);
2025                 }
2026         }
2027         free(in_pack.array);
2028 }
2029
2030 static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2031 {
2032         static struct packed_git *last_found = (void *)1;
2033         struct packed_git *p;
2034
2035         p = (last_found != (void *)1) ? last_found : packed_git;
2036
2037         while (p) {
2038                 if ((!p->pack_local || p->pack_keep) &&
2039                         find_pack_entry_one(sha1, p)) {
2040                         last_found = p;
2041                         return 1;
2042                 }
2043                 if (p == last_found)
2044                         p = packed_git;
2045                 else
2046                         p = p->next;
2047                 if (p == last_found)
2048                         p = p->next;
2049         }
2050         return 0;
2051 }
2052
2053 static void loosen_unused_packed_objects(struct rev_info *revs)
2054 {
2055         struct packed_git *p;
2056         uint32_t i;
2057         const unsigned char *sha1;
2058
2059         for (p = packed_git; p; p = p->next) {
2060                 if (!p->pack_local || p->pack_keep)
2061                         continue;
2062
2063                 if (open_pack_index(p))
2064                         die("cannot open pack index");
2065
2066                 for (i = 0; i < p->num_objects; i++) {
2067                         sha1 = nth_packed_object_sha1(p, i);
2068                         if (!locate_object_entry(sha1) &&
2069                                 !has_sha1_pack_kept_or_nonlocal(sha1))
2070                                 if (force_object_loose(sha1, p->mtime))
2071                                         die("unable to force loose object");
2072                 }
2073         }
2074 }
2075
2076 static void get_object_list(int ac, const char **av)
2077 {
2078         struct rev_info revs;
2079         char line[1000];
2080         int flags = 0;
2081
2082         init_revisions(&revs, NULL);
2083         save_commit_buffer = 0;
2084         setup_revisions(ac, av, &revs, NULL);
2085
2086         while (fgets(line, sizeof(line), stdin) != NULL) {
2087                 int len = strlen(line);
2088                 if (len && line[len - 1] == '\n')
2089                         line[--len] = 0;
2090                 if (!len)
2091                         break;
2092                 if (*line == '-') {
2093                         if (!strcmp(line, "--not")) {
2094                                 flags ^= UNINTERESTING;
2095                                 continue;
2096                         }
2097                         die("not a rev '%s'", line);
2098                 }
2099                 if (handle_revision_arg(line, &revs, flags, 1))
2100                         die("bad revision '%s'", line);
2101         }
2102
2103         if (prepare_revision_walk(&revs))
2104                 die("revision walk setup failed");
2105         mark_edges_uninteresting(revs.commits, &revs, show_edge);
2106         traverse_commit_list(&revs, show_commit, show_object, NULL);
2107
2108         if (keep_unreachable)
2109                 add_objects_in_unpacked_packs(&revs);
2110         if (unpack_unreachable)
2111                 loosen_unused_packed_objects(&revs);
2112 }
2113
2114 static int adjust_perm(const char *path, mode_t mode)
2115 {
2116         if (chmod(path, mode))
2117                 return -1;
2118         return adjust_shared_perm(path);
2119 }
2120
2121 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2122 {
2123         int use_internal_rev_list = 0;
2124         int thin = 0;
2125         uint32_t i;
2126         const char **rp_av;
2127         int rp_ac_alloc = 64;
2128         int rp_ac;
2129
2130         read_replace_refs = 0;
2131
2132         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2133
2134         rp_av[0] = "pack-objects";
2135         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2136         rp_ac = 2;
2137
2138         git_config(git_pack_config, NULL);
2139         if (!pack_compression_seen && core_compression_seen)
2140                 pack_compression_level = core_compression_level;
2141
2142         progress = isatty(2);
2143         for (i = 1; i < argc; i++) {
2144                 const char *arg = argv[i];
2145
2146                 if (*arg != '-')
2147                         break;
2148
2149                 if (!strcmp("--non-empty", arg)) {
2150                         non_empty = 1;
2151                         continue;
2152                 }
2153                 if (!strcmp("--local", arg)) {
2154                         local = 1;
2155                         continue;
2156                 }
2157                 if (!strcmp("--incremental", arg)) {
2158                         incremental = 1;
2159                         continue;
2160                 }
2161                 if (!strcmp("--honor-pack-keep", arg)) {
2162                         ignore_packed_keep = 1;
2163                         continue;
2164                 }
2165                 if (!prefixcmp(arg, "--compression=")) {
2166                         char *end;
2167                         int level = strtoul(arg+14, &end, 0);
2168                         if (!arg[14] || *end)
2169                                 usage(pack_usage);
2170                         if (level == -1)
2171                                 level = Z_DEFAULT_COMPRESSION;
2172                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2173                                 die("bad pack compression level %d", level);
2174                         pack_compression_level = level;
2175                         continue;
2176                 }
2177                 if (!prefixcmp(arg, "--max-pack-size=")) {
2178                         char *end;
2179                         pack_size_limit_cfg = 0;
2180                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2181                         if (!arg[16] || *end)
2182                                 usage(pack_usage);
2183                         continue;
2184                 }
2185                 if (!prefixcmp(arg, "--window=")) {
2186                         char *end;
2187                         window = strtoul(arg+9, &end, 0);
2188                         if (!arg[9] || *end)
2189                                 usage(pack_usage);
2190                         continue;
2191                 }
2192                 if (!prefixcmp(arg, "--window-memory=")) {
2193                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2194                                 usage(pack_usage);
2195                         continue;
2196                 }
2197                 if (!prefixcmp(arg, "--threads=")) {
2198                         char *end;
2199                         delta_search_threads = strtoul(arg+10, &end, 0);
2200                         if (!arg[10] || *end || delta_search_threads < 0)
2201                                 usage(pack_usage);
2202 #ifndef THREADED_DELTA_SEARCH
2203                         if (delta_search_threads != 1)
2204                                 warning("no threads support, "
2205                                         "ignoring %s", arg);
2206 #endif
2207                         continue;
2208                 }
2209                 if (!prefixcmp(arg, "--depth=")) {
2210                         char *end;
2211                         depth = strtoul(arg+8, &end, 0);
2212                         if (!arg[8] || *end)
2213                                 usage(pack_usage);
2214                         continue;
2215                 }
2216                 if (!strcmp("--progress", arg)) {
2217                         progress = 1;
2218                         continue;
2219                 }
2220                 if (!strcmp("--all-progress", arg)) {
2221                         progress = 2;
2222                         continue;
2223                 }
2224                 if (!strcmp("-q", arg)) {
2225                         progress = 0;
2226                         continue;
2227                 }
2228                 if (!strcmp("--no-reuse-delta", arg)) {
2229                         reuse_delta = 0;
2230                         continue;
2231                 }
2232                 if (!strcmp("--no-reuse-object", arg)) {
2233                         reuse_object = reuse_delta = 0;
2234                         continue;
2235                 }
2236                 if (!strcmp("--delta-base-offset", arg)) {
2237                         allow_ofs_delta = 1;
2238                         continue;
2239                 }
2240                 if (!strcmp("--stdout", arg)) {
2241                         pack_to_stdout = 1;
2242                         continue;
2243                 }
2244                 if (!strcmp("--revs", arg)) {
2245                         use_internal_rev_list = 1;
2246                         continue;
2247                 }
2248                 if (!strcmp("--keep-unreachable", arg)) {
2249                         keep_unreachable = 1;
2250                         continue;
2251                 }
2252                 if (!strcmp("--unpack-unreachable", arg)) {
2253                         unpack_unreachable = 1;
2254                         continue;
2255                 }
2256                 if (!strcmp("--include-tag", arg)) {
2257                         include_tag = 1;
2258                         continue;
2259                 }
2260                 if (!strcmp("--unpacked", arg) ||
2261                     !strcmp("--reflog", arg) ||
2262                     !strcmp("--all", arg)) {
2263                         use_internal_rev_list = 1;
2264                         if (rp_ac >= rp_ac_alloc - 1) {
2265                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2266                                 rp_av = xrealloc(rp_av,
2267                                                  rp_ac_alloc * sizeof(*rp_av));
2268                         }
2269                         rp_av[rp_ac++] = arg;
2270                         continue;
2271                 }
2272                 if (!strcmp("--thin", arg)) {
2273                         use_internal_rev_list = 1;
2274                         thin = 1;
2275                         rp_av[1] = "--objects-edge";
2276                         continue;
2277                 }
2278                 if (!prefixcmp(arg, "--index-version=")) {
2279                         char *c;
2280                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2281                         if (pack_idx_default_version > 2)
2282                                 die("bad %s", arg);
2283                         if (*c == ',')
2284                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2285                         if (*c || pack_idx_off32_limit & 0x80000000)
2286                                 die("bad %s", arg);
2287                         continue;
2288                 }
2289                 if (!strcmp(arg, "--keep-true-parents")) {
2290                         grafts_replace_parents = 0;
2291                         continue;
2292                 }
2293                 usage(pack_usage);
2294         }
2295
2296         /* Traditionally "pack-objects [options] base extra" failed;
2297          * we would however want to take refs parameter that would
2298          * have been given to upstream rev-list ourselves, which means
2299          * we somehow want to say what the base name is.  So the
2300          * syntax would be:
2301          *
2302          * pack-objects [options] base <refs...>
2303          *
2304          * in other words, we would treat the first non-option as the
2305          * base_name and send everything else to the internal revision
2306          * walker.
2307          */
2308
2309         if (!pack_to_stdout)
2310                 base_name = argv[i++];
2311
2312         if (pack_to_stdout != !base_name)
2313                 usage(pack_usage);
2314
2315         if (!pack_to_stdout && !pack_size_limit)
2316                 pack_size_limit = pack_size_limit_cfg;
2317
2318         if (pack_to_stdout && pack_size_limit)
2319                 die("--max-pack-size cannot be used to build a pack for transfer.");
2320
2321         if (!pack_to_stdout && thin)
2322                 die("--thin cannot be used to build an indexable pack.");
2323
2324         if (keep_unreachable && unpack_unreachable)
2325                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2326
2327 #ifdef THREADED_DELTA_SEARCH
2328         if (!delta_search_threads)      /* --threads=0 means autodetect */
2329                 delta_search_threads = online_cpus();
2330 #endif
2331
2332         prepare_packed_git();
2333
2334         if (progress)
2335                 progress_state = start_progress("Counting objects", 0);
2336         if (!use_internal_rev_list)
2337                 read_object_list_from_stdin();
2338         else {
2339                 rp_av[rp_ac] = NULL;
2340                 get_object_list(rp_ac, rp_av);
2341         }
2342         cleanup_preferred_base();
2343         if (include_tag && nr_result)
2344                 for_each_ref(add_ref_tag, NULL);
2345         stop_progress(&progress_state);
2346
2347         if (non_empty && !nr_result)
2348                 return 0;
2349         if (nr_result)
2350                 prepare_pack(window, depth);
2351         write_pack_file();
2352         if (progress)
2353                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2354                         " reused %"PRIu32" (delta %"PRIu32")\n",
2355                         written, written_delta, reused, reused_delta);
2356         return 0;
2357 }