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   "        [--all-progress-implied]\n"
  28   "        [--max-pack-size=N] [--local] [--incremental]\n"
  29   "        [--window=N] [--window-memory=N] [--depth=N]\n"
  30   "        [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset]\n"
  31   "        [--threads=N] [--non-empty] [--revs [--unpacked | --all]*]\n"
  32   "        [--reflog] [--stdout | base-name] [--include-tag]\n"
  33   "        [--keep-unreachable | --unpack-unreachable \n"
  34   "        [<ref-list | <object-list]";
  35
  36 struct object_entry {
  37         struct pack_idx_entry idx;
  38         unsigned long size;     /* uncompressed size */
  39         struct packed_git *in_pack;     /* already in pack */
  40         off_t in_pack_offset;
  41         struct object_entry *delta;     /* delta base object */
  42         struct object_entry *delta_child; /* deltified objects who bases me */
  43         struct object_entry *delta_sibling; /* other deltified objects who
  44                                              * uses the same base as me
  45                                              */
  46         void *delta_data;       /* cached delta (uncompressed) */
  47         unsigned long delta_size;       /* delta data size (uncompressed) */
  48         unsigned long z_delta_size;     /* delta data size (compressed) */
  49         unsigned int hash;      /* name hint hash */
  50         enum object_type type;
  51         enum object_type in_pack_type;  /* could be delta */
  52         unsigned char in_pack_header_size;
  53         unsigned char preferred_base; /* we do not pack this, but is available
  54                                        * to be used as the base object to delta
  55                                        * objects against.
  56                                        */
  57         unsigned char no_try_delta;
  58 };
  59
  60 /*
  61  * Objects we are going to pack are collected in objects array (dynamically
  62  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  63  * in the order we see -- typically rev-list --objects order that gives us
  64  * nice "minimum seek" order.
  65  */
  66 static struct object_entry *objects;
  67 static struct pack_idx_entry **written_list;
  68 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
  69
  70 static int non_empty;
  71 static int reuse_delta = 1, reuse_object = 1;
  72 static int keep_unreachable, unpack_unreachable, include_tag;
  73 static int local;
  74 static int incremental;
  75 static int ignore_packed_keep;
  76 static int allow_ofs_delta;
  77 static const char *base_name;
  78 static int progress = 1;
  79 static int window = 10;
  80 static uint32_t pack_size_limit, pack_size_limit_cfg;
  81 static int depth = 50;
  82 static int delta_search_threads;
  83 static int pack_to_stdout;
  84 static int num_preferred_base;
  85 static struct progress *progress_state;
  86 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  87 static int pack_compression_seen;
  88
  89 static unsigned long delta_cache_size = 0;
  90 static unsigned long max_delta_cache_size = 256 * 1024 * 1024;
  91 static unsigned long cache_max_small_delta_size = 1000;
  92
  93 static unsigned long window_memory_limit = 0;
  94
  95 /*
  96  * The object names in objects array are hashed with this hashtable,
  97  * to help looking up the entry by object name.
  98  * This hashtable is built after all the objects are seen.
  99  */
 100 static int *object_ix;
 101 static int object_ix_hashsz;
 102
 103 /*
 104  * stats
 105  */
 106 static uint32_t written, written_delta;
 107 static uint32_t reused, reused_delta;
 108
 109
 110 static void *get_delta(struct object_entry *entry)
 111 {
 112         unsigned long size, base_size, delta_size;
 113         void *buf, *base_buf, *delta_buf;
 114         enum object_type type;
 115
 116         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 117         if (!buf)
 118                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 119         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
 120         if (!base_buf)
 121                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 122         delta_buf = diff_delta(base_buf, base_size,
 123                                buf, size, &delta_size, 0);
 124         if (!delta_buf || delta_size != entry->delta_size)
 125                 die("delta size changed");
 126         free(buf);
 127         free(base_buf);
 128         return delta_buf;
 129 }
 130
 131 static unsigned long do_compress(void **pptr, unsigned long size)
 132 {
 133         z_stream stream;
 134         void *in, *out;
 135         unsigned long maxsize;
 136
 137         memset(&stream, 0, sizeof(stream));
 138         deflateInit(&stream, pack_compression_level);
 139         maxsize = deflateBound(&stream, size);
 140
 141         in = *pptr;
 142         out = xmalloc(maxsize);
 143         *pptr = out;
 144
 145         stream.next_in = in;
 146         stream.avail_in = size;
 147         stream.next_out = out;
 148         stream.avail_out = maxsize;
 149         while (deflate(&stream, Z_FINISH) == Z_OK)
 150                 ; /* nothing */
 151         deflateEnd(&stream);
 152
 153         free(in);
 154         return stream.total_out;
 155 }
 156
 157 /*
 158  * The per-object header is a pretty dense thing, which is
 159  *  - first byte: low four bits are "size", then three bits of "type",
 160  *    and the high bit is "size continues".
 161  *  - each byte afterwards: low seven bits are size continuation,
 162  *    with the high bit being "size continues"
 163  */
 164 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 165 {
 166         int n = 1;
 167         unsigned char c;
 168
 169         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 170                 die("bad type %d", type);
 171
 172         c = (type << 4) | (size & 15);
 173         size >>= 4;
 174         while (size) {
 175                 *hdr++ = c | 0x80;
 176                 c = size & 0x7f;
 177                 size >>= 7;
 178                 n++;
 179         }
 180         *hdr = c;
 181         return n;
 182 }
 183
 184 /*
 185  * we are going to reuse the existing object data as is.  make
 186  * sure it is not corrupt.
 187  */
 188 static int check_pack_inflate(struct packed_git *p,
 189                 struct pack_window **w_curs,
 190                 off_t offset,
 191                 off_t len,
 192                 unsigned long expect)
 193 {
 194         z_stream stream;
 195         unsigned char fakebuf[4096], *in;
 196         int st;
 197
 198         memset(&stream, 0, sizeof(stream));
 199         git_inflate_init(&stream);
 200         do {
 201                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 202                 stream.next_in = in;
 203                 stream.next_out = fakebuf;
 204                 stream.avail_out = sizeof(fakebuf);
 205                 st = git_inflate(&stream, Z_FINISH);
 206                 offset += stream.next_in - in;
 207         } while (st == Z_OK || st == Z_BUF_ERROR);
 208         git_inflate_end(&stream);
 209         return (st == Z_STREAM_END &&
 210                 stream.total_out == expect &&
 211                 stream.total_in == len) ? 0 : -1;
 212 }
 213
 214 static void copy_pack_data(struct sha1file *f,
 215                 struct packed_git *p,
 216                 struct pack_window **w_curs,
 217                 off_t offset,
 218                 off_t len)
 219 {
 220         unsigned char *in;
 221         unsigned int avail;
 222
 223         while (len) {
 224                 in = use_pack(p, w_curs, offset, &avail);
 225                 if (avail > len)
 226                         avail = (unsigned int)len;
 227                 sha1write(f, in, avail);
 228                 offset += avail;
 229                 len -= avail;
 230         }
 231 }
 232
 233 static unsigned long write_object(struct sha1file *f,
 234                                   struct object_entry *entry,
 235                                   off_t write_offset)
 236 {
 237         unsigned long size, limit, datalen;
 238         void *buf;
 239         unsigned char header[10], dheader[10];
 240         unsigned hdrlen;
 241         enum object_type type;
 242         int usable_delta, to_reuse;
 243
 244         if (!pack_to_stdout)
 245                 crc32_begin(f);
 246
 247         type = entry->type;
 248
 249         /* write limit if limited packsize and not first object */
 250         if (!pack_size_limit || !nr_written)
 251                 limit = 0;
 252         else if (pack_size_limit <= write_offset)
 253                 /*
 254                  * the earlier object did not fit the limit; avoid
 255                  * mistaking this with unlimited (i.e. limit = 0).
 256                  */
 257                 limit = 1;
 258         else
 259                 limit = pack_size_limit - write_offset;
 260
 261         if (!entry->delta)
 262                 usable_delta = 0;       /* no delta */
 263         else if (!pack_size_limit)
 264                usable_delta = 1;        /* unlimited packfile */
 265         else if (entry->delta->idx.offset == (off_t)-1)
 266                 usable_delta = 0;       /* base was written to another pack */
 267         else if (entry->delta->idx.offset)
 268                 usable_delta = 1;       /* base already exists in this pack */
 269         else
 270                 usable_delta = 0;       /* base could end up in another pack */
 271
 272         if (!reuse_object)
 273                 to_reuse = 0;   /* explicit */
 274         else if (!entry->in_pack)
 275                 to_reuse = 0;   /* can't reuse what we don't have */
 276         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
 277                                 /* check_object() decided it for us ... */
 278                 to_reuse = usable_delta;
 279                                 /* ... but pack split may override that */
 280         else if (type != entry->in_pack_type)
 281                 to_reuse = 0;   /* pack has delta which is unusable */
 282         else if (entry->delta)
 283                 to_reuse = 0;   /* we want to pack afresh */
 284         else
 285                 to_reuse = 1;   /* we have it in-pack undeltified,
 286                                  * and we do not need to deltify it.
 287                                  */
 288
 289         if (!to_reuse) {
 290                 no_reuse:
 291                 if (!usable_delta) {
 292                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 293                         if (!buf)
 294                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 295                         /*
 296                          * make sure no cached delta data remains from a
 297                          * previous attempt before a pack split occurred.
 298                          */
 299                         free(entry->delta_data);
 300                         entry->delta_data = NULL;
 301                         entry->z_delta_size = 0;
 302                 } else if (entry->delta_data) {
 303                         size = entry->delta_size;
 304                         buf = entry->delta_data;
 305                         entry->delta_data = NULL;
 306                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 307                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 308                 } else {
 309                         buf = get_delta(entry);
 310                         size = entry->delta_size;
 311                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 312                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 313                 }
 314
 315                 if (entry->z_delta_size)
 316                         datalen = entry->z_delta_size;
 317                 else
 318                         datalen = do_compress(&buf, size);
 319
 320                 /*
 321                  * The object header is a byte of 'type' followed by zero or
 322                  * more bytes of length.
 323                  */
 324                 hdrlen = encode_header(type, size, header);
 325
 326                 if (type == OBJ_OFS_DELTA) {
 327                         /*
 328                          * Deltas with relative base contain an additional
 329                          * encoding of the relative offset for the delta
 330                          * base from this object's position in the pack.
 331                          */
 332                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 333                         unsigned pos = sizeof(dheader) - 1;
 334                         dheader[pos] = ofs & 127;
 335                         while (ofs >>= 7)
 336                                 dheader[--pos] = 128 | (--ofs & 127);
 337                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 338                                 free(buf);
 339                                 return 0;
 340                         }
 341                         sha1write(f, header, hdrlen);
 342                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 343                         hdrlen += sizeof(dheader) - pos;
 344                 } else if (type == OBJ_REF_DELTA) {
 345                         /*
 346                          * Deltas with a base reference contain
 347                          * an additional 20 bytes for the base sha1.
 348                          */
 349                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 350                                 free(buf);
 351                                 return 0;
 352                         }
 353                         sha1write(f, header, hdrlen);
 354                         sha1write(f, entry->delta->idx.sha1, 20);
 355                         hdrlen += 20;
 356                 } else {
 357                         if (limit && hdrlen + datalen + 20 >= limit) {
 358                                 free(buf);
 359                                 return 0;
 360                         }
 361                         sha1write(f, header, hdrlen);
 362                 }
 363                 sha1write(f, buf, datalen);
 364                 free(buf);
 365         }
 366         else {
 367                 struct packed_git *p = entry->in_pack;
 368                 struct pack_window *w_curs = NULL;
 369                 struct revindex_entry *revidx;
 370                 off_t offset;
 371
 372                 if (entry->delta)
 373                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 374                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 375                 hdrlen = encode_header(type, entry->size, header);
 376
 377                 offset = entry->in_pack_offset;
 378                 revidx = find_pack_revindex(p, offset);
 379                 datalen = revidx[1].offset - offset;
 380                 if (!pack_to_stdout && p->index_version > 1 &&
 381                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 382                         error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 383                         unuse_pack(&w_curs);
 384                         goto no_reuse;
 385                 }
 386
 387                 offset += entry->in_pack_header_size;
 388                 datalen -= entry->in_pack_header_size;
 389                 if (!pack_to_stdout && p->index_version == 1 &&
 390                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
 391                         error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 392                         unuse_pack(&w_curs);
 393                         goto no_reuse;
 394                 }
 395
 396                 if (type == OBJ_OFS_DELTA) {
 397                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 398                         unsigned pos = sizeof(dheader) - 1;
 399                         dheader[pos] = ofs & 127;
 400                         while (ofs >>= 7)
 401                                 dheader[--pos] = 128 | (--ofs & 127);
 402                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 403                                 unuse_pack(&w_curs);
 404                                 return 0;
 405                         }
 406                         sha1write(f, header, hdrlen);
 407                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 408                         hdrlen += sizeof(dheader) - pos;
 409                         reused_delta++;
 410                 } else if (type == OBJ_REF_DELTA) {
 411                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 412                                 unuse_pack(&w_curs);
 413                                 return 0;
 414                         }
 415                         sha1write(f, header, hdrlen);
 416                         sha1write(f, entry->delta->idx.sha1, 20);
 417                         hdrlen += 20;
 418                         reused_delta++;
 419                 } else {
 420                         if (limit && hdrlen + datalen + 20 >= limit) {
 421                                 unuse_pack(&w_curs);
 422                                 return 0;
 423                         }
 424                         sha1write(f, header, hdrlen);
 425                 }
 426                 copy_pack_data(f, p, &w_curs, offset, datalen);
 427                 unuse_pack(&w_curs);
 428                 reused++;
 429         }
 430         if (usable_delta)
 431                 written_delta++;
 432         written++;
 433         if (!pack_to_stdout)
 434                 entry->idx.crc32 = crc32_end(f);
 435         return hdrlen + datalen;
 436 }
 437
 438 static int write_one(struct sha1file *f,
 439                                struct object_entry *e,
 440                                off_t *offset)
 441 {
 442         unsigned long size;
 443
 444         /* offset is non zero if object is written already. */
 445         if (e->idx.offset || e->preferred_base)
 446                 return 1;
 447
 448         /* if we are deltified, write out base object first. */
 449         if (e->delta && !write_one(f, e->delta, offset))
 450                 return 0;
 451
 452         e->idx.offset = *offset;
 453         size = write_object(f, e, *offset);
 454         if (!size) {
 455                 e->idx.offset = 0;
 456                 return 0;
 457         }
 458         written_list[nr_written++] = &e->idx;
 459
 460         /* make sure off_t is sufficiently large not to wrap */
 461         if (*offset > *offset + size)
 462                 die("pack too large for current definition of off_t");
 463         *offset += size;
 464         return 1;
 465 }
 466
 467 /* forward declaration for write_pack_file */
 468 static int adjust_perm(const char *path, mode_t mode);
 469
 470 static void write_pack_file(void)
 471 {
 472         uint32_t i = 0, j;
 473         struct sha1file *f;
 474         off_t offset;
 475         struct pack_header hdr;
 476         uint32_t nr_remaining = nr_result;
 477         time_t last_mtime = 0;
 478
 479         if (progress > pack_to_stdout)
 480                 progress_state = start_progress("Writing objects", nr_result);
 481         written_list = xmalloc(nr_objects * sizeof(*written_list));
 482
 483         do {
 484                 unsigned char sha1[20];
 485                 char *pack_tmp_name = NULL;
 486
 487                 if (pack_to_stdout) {
 488                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 489                 } else {
 490                         char tmpname[PATH_MAX];
 491                         int fd;
 492                         fd = odb_mkstemp(tmpname, sizeof(tmpname),
 493                                          "pack/tmp_pack_XXXXXX");
 494                         pack_tmp_name = xstrdup(tmpname);
 495                         f = sha1fd(fd, pack_tmp_name);
 496                 }
 497
 498                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
 499                 hdr.hdr_version = htonl(PACK_VERSION);
 500                 hdr.hdr_entries = htonl(nr_remaining);
 501                 sha1write(f, &hdr, sizeof(hdr));
 502                 offset = sizeof(hdr);
 503                 nr_written = 0;
 504                 for (; i < nr_objects; i++) {
 505                         if (!write_one(f, objects + i, &offset))
 506                                 break;
 507                         display_progress(progress_state, written);
 508                 }
 509
 510                 /*
 511                  * Did we write the wrong # entries in the header?
 512                  * If so, rewrite it like in fast-import
 513                  */
 514                 if (pack_to_stdout) {
 515                         sha1close(f, sha1, CSUM_CLOSE);
 516                 } else if (nr_written == nr_remaining) {
 517                         sha1close(f, sha1, CSUM_FSYNC);
 518                 } else {
 519                         int fd = sha1close(f, sha1, 0);
 520                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
 521                                                  nr_written, sha1, offset);
 522                         close(fd);
 523                 }
 524
 525                 if (!pack_to_stdout) {
 526                         mode_t mode = umask(0);
 527                         struct stat st;
 528                         const char *idx_tmp_name;
 529                         char tmpname[PATH_MAX];
 530
 531                         umask(mode);
 532                         mode = 0444 & ~mode;
 533
 534                         idx_tmp_name = write_idx_file(NULL, written_list,
 535                                                       nr_written, sha1);
 536
 537                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 538                                  base_name, sha1_to_hex(sha1));
 539                         free_pack_by_name(tmpname);
 540                         if (adjust_perm(pack_tmp_name, mode))
 541                                 die_errno("unable to make temporary pack file readable");
 542                         if (rename(pack_tmp_name, tmpname))
 543                                 die_errno("unable to rename temporary pack file");
 544
 545                         /*
 546                          * Packs are runtime accessed in their mtime
 547                          * order since newer packs are more likely to contain
 548                          * younger objects.  So if we are creating multiple
 549                          * packs then we should modify the mtime of later ones
 550                          * to preserve this property.
 551                          */
 552                         if (stat(tmpname, &st) < 0) {
 553                                 warning("failed to stat %s: %s",
 554                                         tmpname, strerror(errno));
 555                         } else if (!last_mtime) {
 556                                 last_mtime = st.st_mtime;
 557                         } else {
 558                                 struct utimbuf utb;
 559                                 utb.actime = st.st_atime;
 560                                 utb.modtime = --last_mtime;
 561                                 if (utime(tmpname, &utb) < 0)
 562                                         warning("failed utime() on %s: %s",
 563                                                 tmpname, strerror(errno));
 564                         }
 565
 566                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 567                                  base_name, sha1_to_hex(sha1));
 568                         if (adjust_perm(idx_tmp_name, mode))
 569                                 die_errno("unable to make temporary index file readable");
 570                         if (rename(idx_tmp_name, tmpname))
 571                                 die_errno("unable to rename temporary index file");
 572
 573                         free((void *) idx_tmp_name);
 574                         free(pack_tmp_name);
 575                         puts(sha1_to_hex(sha1));
 576                 }
 577
 578                 /* mark written objects as written to previous pack */
 579                 for (j = 0; j < nr_written; j++) {
 580                         written_list[j]->offset = (off_t)-1;
 581                 }
 582                 nr_remaining -= nr_written;
 583         } while (nr_remaining && i < nr_objects);
 584
 585         free(written_list);
 586         stop_progress(&progress_state);
 587         if (written != nr_result)
 588                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
 589                         written, nr_result);
 590         /*
 591          * We have scanned through [0 ... i).  Since we have written
 592          * the correct number of objects,  the remaining [i ... nr_objects)
 593          * items must be either already written (due to out-of-order delta base)
 594          * or a preferred base.  Count those which are neither and complain if any.
 595          */
 596         for (j = 0; i < nr_objects; i++) {
 597                 struct object_entry *e = objects + i;
 598                 j += !e->idx.offset && !e->preferred_base;
 599         }
 600         if (j)
 601                 die("wrote %"PRIu32" objects as expected but %"PRIu32
 602                         " unwritten", written, j);
 603 }
 604
 605 static int locate_object_entry_hash(const unsigned char *sha1)
 606 {
 607         int i;
 608         unsigned int ui;
 609         memcpy(&ui, sha1, sizeof(unsigned int));
 610         i = ui % object_ix_hashsz;
 611         while (0 < object_ix[i]) {
 612                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 613                         return i;
 614                 if (++i == object_ix_hashsz)
 615                         i = 0;
 616         }
 617         return -1 - i;
 618 }
 619
 620 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 621 {
 622         int i;
 623
 624         if (!object_ix_hashsz)
 625                 return NULL;
 626
 627         i = locate_object_entry_hash(sha1);
 628         if (0 <= i)
 629                 return &objects[object_ix[i]-1];
 630         return NULL;
 631 }
 632
 633 static void rehash_objects(void)
 634 {
 635         uint32_t i;
 636         struct object_entry *oe;
 637
 638         object_ix_hashsz = nr_objects * 3;
 639         if (object_ix_hashsz < 1024)
 640                 object_ix_hashsz = 1024;
 641         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 642         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 643         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 644                 int ix = locate_object_entry_hash(oe->idx.sha1);
 645                 if (0 <= ix)
 646                         continue;
 647                 ix = -1 - ix;
 648                 object_ix[ix] = i + 1;
 649         }
 650 }
 651
 652 static unsigned name_hash(const char *name)
 653 {
 654         unsigned c, hash = 0;
 655
 656         if (!name)
 657                 return 0;
 658
 659         /*
 660          * This effectively just creates a sortable number from the
 661          * last sixteen non-whitespace characters. Last characters
 662          * count "most", so things that end in ".c" sort together.
 663          */
 664         while ((c = *name++) != 0) {
 665                 if (isspace(c))
 666                         continue;
 667                 hash = (hash >> 2) + (c << 24);
 668         }
 669         return hash;
 670 }
 671
 672 static void setup_delta_attr_check(struct git_attr_check *check)
 673 {
 674         static struct git_attr *attr_delta;
 675
 676         if (!attr_delta)
 677                 attr_delta = git_attr("delta");
 678
 679         check[0].attr = attr_delta;
 680 }
 681
 682 static int no_try_delta(const char *path)
 683 {
 684         struct git_attr_check check[1];
 685
 686         setup_delta_attr_check(check);
 687         if (git_checkattr(path, ARRAY_SIZE(check), check))
 688                 return 0;
 689         if (ATTR_FALSE(check->value))
 690                 return 1;
 691         return 0;
 692 }
 693
 694 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 695                             const char *name, int exclude)
 696 {
 697         struct object_entry *entry;
 698         struct packed_git *p, *found_pack = NULL;
 699         off_t found_offset = 0;
 700         int ix;
 701         unsigned hash = name_hash(name);
 702
 703         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 704         if (ix >= 0) {
 705                 if (exclude) {
 706                         entry = objects + object_ix[ix] - 1;
 707                         if (!entry->preferred_base)
 708                                 nr_result--;
 709                         entry->preferred_base = 1;
 710                 }
 711                 return 0;
 712         }
 713
 714         if (!exclude && local && has_loose_object_nonlocal(sha1))
 715                 return 0;
 716
 717         for (p = packed_git; p; p = p->next) {
 718                 off_t offset = find_pack_entry_one(sha1, p);
 719                 if (offset) {
 720                         if (!found_pack) {
 721                                 found_offset = offset;
 722                                 found_pack = p;
 723                         }
 724                         if (exclude)
 725                                 break;
 726                         if (incremental)
 727                                 return 0;
 728                         if (local && !p->pack_local)
 729                                 return 0;
 730                         if (ignore_packed_keep && p->pack_local && p->pack_keep)
 731                                 return 0;
 732                 }
 733         }
 734
 735         if (nr_objects >= nr_alloc) {
 736                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 737                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 738         }
 739
 740         entry = objects + nr_objects++;
 741         memset(entry, 0, sizeof(*entry));
 742         hashcpy(entry->idx.sha1, sha1);
 743         entry->hash = hash;
 744         if (type)
 745                 entry->type = type;
 746         if (exclude)
 747                 entry->preferred_base = 1;
 748         else
 749                 nr_result++;
 750         if (found_pack) {
 751                 entry->in_pack = found_pack;
 752                 entry->in_pack_offset = found_offset;
 753         }
 754
 755         if (object_ix_hashsz * 3 <= nr_objects * 4)
 756                 rehash_objects();
 757         else
 758                 object_ix[-1 - ix] = nr_objects;
 759
 760         display_progress(progress_state, nr_objects);
 761
 762         if (name && no_try_delta(name))
 763                 entry->no_try_delta = 1;
 764
 765         return 1;
 766 }
 767
 768 struct pbase_tree_cache {
 769         unsigned char sha1[20];
 770         int ref;
 771         int temporary;
 772         void *tree_data;
 773         unsigned long tree_size;
 774 };
 775
 776 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 777 static int pbase_tree_cache_ix(const unsigned char *sha1)
 778 {
 779         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 780 }
 781 static int pbase_tree_cache_ix_incr(int ix)
 782 {
 783         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 784 }
 785
 786 static struct pbase_tree {
 787         struct pbase_tree *next;
 788         /* This is a phony "cache" entry; we are not
 789          * going to evict it nor find it through _get()
 790          * mechanism -- this is for the toplevel node that
 791          * would almost always change with any commit.
 792          */
 793         struct pbase_tree_cache pcache;
 794 } *pbase_tree;
 795
 796 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 797 {
 798         struct pbase_tree_cache *ent, *nent;
 799         void *data;
 800         unsigned long size;
 801         enum object_type type;
 802         int neigh;
 803         int my_ix = pbase_tree_cache_ix(sha1);
 804         int available_ix = -1;
 805
 806         /* pbase-tree-cache acts as a limited hashtable.
 807          * your object will be found at your index or within a few
 808          * slots after that slot if it is cached.
 809          */
 810         for (neigh = 0; neigh < 8; neigh++) {
 811                 ent = pbase_tree_cache[my_ix];
 812                 if (ent && !hashcmp(ent->sha1, sha1)) {
 813                         ent->ref++;
 814                         return ent;
 815                 }
 816                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 817                          ((0 <= available_ix) &&
 818                           (!ent && pbase_tree_cache[available_ix])))
 819                         available_ix = my_ix;
 820                 if (!ent)
 821                         break;
 822                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 823         }
 824
 825         /* Did not find one.  Either we got a bogus request or
 826          * we need to read and perhaps cache.
 827          */
 828         data = read_sha1_file(sha1, &type, &size);
 829         if (!data)
 830                 return NULL;
 831         if (type != OBJ_TREE) {
 832                 free(data);
 833                 return NULL;
 834         }
 835
 836         /* We need to either cache or return a throwaway copy */
 837
 838         if (available_ix < 0)
 839                 ent = NULL;
 840         else {
 841                 ent = pbase_tree_cache[available_ix];
 842                 my_ix = available_ix;
 843         }
 844
 845         if (!ent) {
 846                 nent = xmalloc(sizeof(*nent));
 847                 nent->temporary = (available_ix < 0);
 848         }
 849         else {
 850                 /* evict and reuse */
 851                 free(ent->tree_data);
 852                 nent = ent;
 853         }
 854         hashcpy(nent->sha1, sha1);
 855         nent->tree_data = data;
 856         nent->tree_size = size;
 857         nent->ref = 1;
 858         if (!nent->temporary)
 859                 pbase_tree_cache[my_ix] = nent;
 860         return nent;
 861 }
 862
 863 static void pbase_tree_put(struct pbase_tree_cache *cache)
 864 {
 865         if (!cache->temporary) {
 866                 cache->ref--;
 867                 return;
 868         }
 869         free(cache->tree_data);
 870         free(cache);
 871 }
 872
 873 static int name_cmp_len(const char *name)
 874 {
 875         int i;
 876         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 877                 ;
 878         return i;
 879 }
 880
 881 static void add_pbase_object(struct tree_desc *tree,
 882                              const char *name,
 883                              int cmplen,
 884                              const char *fullname)
 885 {
 886         struct name_entry entry;
 887         int cmp;
 888
 889         while (tree_entry(tree,&entry)) {
 890                 if (S_ISGITLINK(entry.mode))
 891                         continue;
 892                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 893                       memcmp(name, entry.path, cmplen);
 894                 if (cmp > 0)
 895                         continue;
 896                 if (cmp < 0)
 897                         return;
 898                 if (name[cmplen] != '/') {
 899                         add_object_entry(entry.sha1,
 900                                          object_type(entry.mode),
 901                                          fullname, 1);
 902                         return;
 903                 }
 904                 if (S_ISDIR(entry.mode)) {
 905                         struct tree_desc sub;
 906                         struct pbase_tree_cache *tree;
 907                         const char *down = name+cmplen+1;
 908                         int downlen = name_cmp_len(down);
 909
 910                         tree = pbase_tree_get(entry.sha1);
 911                         if (!tree)
 912                                 return;
 913                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 914
 915                         add_pbase_object(&sub, down, downlen, fullname);
 916                         pbase_tree_put(tree);
 917                 }
 918         }
 919 }
 920
 921 static unsigned *done_pbase_paths;
 922 static int done_pbase_paths_num;
 923 static int done_pbase_paths_alloc;
 924 static int done_pbase_path_pos(unsigned hash)
 925 {
 926         int lo = 0;
 927         int hi = done_pbase_paths_num;
 928         while (lo < hi) {
 929                 int mi = (hi + lo) / 2;
 930                 if (done_pbase_paths[mi] == hash)
 931                         return mi;
 932                 if (done_pbase_paths[mi] < hash)
 933                         hi = mi;
 934                 else
 935                         lo = mi + 1;
 936         }
 937         return -lo-1;
 938 }
 939
 940 static int check_pbase_path(unsigned hash)
 941 {
 942         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 943         if (0 <= pos)
 944                 return 1;
 945         pos = -pos - 1;
 946         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 947                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 948                 done_pbase_paths = xrealloc(done_pbase_paths,
 949                                             done_pbase_paths_alloc *
 950                                             sizeof(unsigned));
 951         }
 952         done_pbase_paths_num++;
 953         if (pos < done_pbase_paths_num)
 954                 memmove(done_pbase_paths + pos + 1,
 955                         done_pbase_paths + pos,
 956                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 957         done_pbase_paths[pos] = hash;
 958         return 0;
 959 }
 960
 961 static void add_preferred_base_object(const char *name)
 962 {
 963         struct pbase_tree *it;
 964         int cmplen;
 965         unsigned hash = name_hash(name);
 966
 967         if (!num_preferred_base || check_pbase_path(hash))
 968                 return;
 969
 970         cmplen = name_cmp_len(name);
 971         for (it = pbase_tree; it; it = it->next) {
 972                 if (cmplen == 0) {
 973                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 974                 }
 975                 else {
 976                         struct tree_desc tree;
 977                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 978                         add_pbase_object(&tree, name, cmplen, name);
 979                 }
 980         }
 981 }
 982
 983 static void add_preferred_base(unsigned char *sha1)
 984 {
 985         struct pbase_tree *it;
 986         void *data;
 987         unsigned long size;
 988         unsigned char tree_sha1[20];
 989
 990         if (window <= num_preferred_base++)
 991                 return;
 992
 993         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 994         if (!data)
 995                 return;
 996
 997         for (it = pbase_tree; it; it = it->next) {
 998                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 999                         free(data);
1000                         return;
1001                 }
1002         }
1003
1004         it = xcalloc(1, sizeof(*it));
1005         it->next = pbase_tree;
1006         pbase_tree = it;
1007
1008         hashcpy(it->pcache.sha1, tree_sha1);
1009         it->pcache.tree_data = data;
1010         it->pcache.tree_size = size;
1011 }
1012
1013 static void cleanup_preferred_base(void)
1014 {
1015         struct pbase_tree *it;
1016         unsigned i;
1017
1018         it = pbase_tree;
1019         pbase_tree = NULL;
1020         while (it) {
1021                 struct pbase_tree *this = it;
1022                 it = this->next;
1023                 free(this->pcache.tree_data);
1024                 free(this);
1025         }
1026
1027         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1028                 if (!pbase_tree_cache[i])
1029                         continue;
1030                 free(pbase_tree_cache[i]->tree_data);
1031                 free(pbase_tree_cache[i]);
1032                 pbase_tree_cache[i] = NULL;
1033         }
1034
1035         free(done_pbase_paths);
1036         done_pbase_paths = NULL;
1037         done_pbase_paths_num = done_pbase_paths_alloc = 0;
1038 }
1039
1040 static void check_object(struct object_entry *entry)
1041 {
1042         if (entry->in_pack) {
1043                 struct packed_git *p = entry->in_pack;
1044                 struct pack_window *w_curs = NULL;
1045                 const unsigned char *base_ref = NULL;
1046                 struct object_entry *base_entry;
1047                 unsigned long used, used_0;
1048                 unsigned int avail;
1049                 off_t ofs;
1050                 unsigned char *buf, c;
1051
1052                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1053
1054                 /*
1055                  * We want in_pack_type even if we do not reuse delta
1056                  * since non-delta representations could still be reused.
1057                  */
1058                 used = unpack_object_header_buffer(buf, avail,
1059                                                    &entry->in_pack_type,
1060                                                    &entry->size);
1061                 if (used == 0)
1062                         goto give_up;
1063
1064                 /*
1065                  * Determine if this is a delta and if so whether we can
1066                  * reuse it or not.  Otherwise let's find out as cheaply as
1067                  * possible what the actual type and size for this object is.
1068                  */
1069                 switch (entry->in_pack_type) {
1070                 default:
1071                         /* Not a delta hence we've already got all we need. */
1072                         entry->type = entry->in_pack_type;
1073                         entry->in_pack_header_size = used;
1074                         if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1075                                 goto give_up;
1076                         unuse_pack(&w_curs);
1077                         return;
1078                 case OBJ_REF_DELTA:
1079                         if (reuse_delta && !entry->preferred_base)
1080                                 base_ref = use_pack(p, &w_curs,
1081                                                 entry->in_pack_offset + used, NULL);
1082                         entry->in_pack_header_size = used + 20;
1083                         break;
1084                 case OBJ_OFS_DELTA:
1085                         buf = use_pack(p, &w_curs,
1086                                        entry->in_pack_offset + used, NULL);
1087                         used_0 = 0;
1088                         c = buf[used_0++];
1089                         ofs = c & 127;
1090                         while (c & 128) {
1091                                 ofs += 1;
1092                                 if (!ofs || MSB(ofs, 7)) {
1093                                         error("delta base offset overflow in pack for %s",
1094                                               sha1_to_hex(entry->idx.sha1));
1095                                         goto give_up;
1096                                 }
1097                                 c = buf[used_0++];
1098                                 ofs = (ofs << 7) + (c & 127);
1099                         }
1100                         ofs = entry->in_pack_offset - ofs;
1101                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1102                                 error("delta base offset out of bound for %s",
1103                                       sha1_to_hex(entry->idx.sha1));
1104                                 goto give_up;
1105                         }
1106                         if (reuse_delta && !entry->preferred_base) {
1107                                 struct revindex_entry *revidx;
1108                                 revidx = find_pack_revindex(p, ofs);
1109                                 if (!revidx)
1110                                         goto give_up;
1111                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1112                         }
1113                         entry->in_pack_header_size = used + used_0;
1114                         break;
1115                 }
1116
1117                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1118                         /*
1119                          * If base_ref was set above that means we wish to
1120                          * reuse delta data, and we even found that base
1121                          * in the list of objects we want to pack. Goodie!
1122                          *
1123                          * Depth value does not matter - find_deltas() will
1124                          * never consider reused delta as the base object to
1125                          * deltify other objects against, in order to avoid
1126                          * circular deltas.
1127                          */
1128                         entry->type = entry->in_pack_type;
1129                         entry->delta = base_entry;
1130                         entry->delta_size = entry->size;
1131                         entry->delta_sibling = base_entry->delta_child;
1132                         base_entry->delta_child = entry;
1133                         unuse_pack(&w_curs);
1134                         return;
1135                 }
1136
1137                 if (entry->type) {
1138                         /*
1139                          * This must be a delta and we already know what the
1140                          * final object type is.  Let's extract the actual
1141                          * object size from the delta header.
1142                          */
1143                         entry->size = get_size_from_delta(p, &w_curs,
1144                                         entry->in_pack_offset + entry->in_pack_header_size);
1145                         if (entry->size == 0)
1146                                 goto give_up;
1147                         unuse_pack(&w_curs);
1148                         return;
1149                 }
1150
1151                 /*
1152                  * No choice but to fall back to the recursive delta walk
1153                  * with sha1_object_info() to find about the object type
1154                  * at this point...
1155                  */
1156                 give_up:
1157                 unuse_pack(&w_curs);
1158         }
1159
1160         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1161         /*
1162          * The error condition is checked in prepare_pack().  This is
1163          * to permit a missing preferred base object to be ignored
1164          * as a preferred base.  Doing so can result in a larger
1165          * pack file, but the transfer will still take place.
1166          */
1167 }
1168
1169 static int pack_offset_sort(const void *_a, const void *_b)
1170 {
1171         const struct object_entry *a = *(struct object_entry **)_a;
1172         const struct object_entry *b = *(struct object_entry **)_b;
1173
1174         /* avoid filesystem trashing with loose objects */
1175         if (!a->in_pack && !b->in_pack)
1176                 return hashcmp(a->idx.sha1, b->idx.sha1);
1177
1178         if (a->in_pack < b->in_pack)
1179                 return -1;
1180         if (a->in_pack > b->in_pack)
1181                 return 1;
1182         return a->in_pack_offset < b->in_pack_offset ? -1 :
1183                         (a->in_pack_offset > b->in_pack_offset);
1184 }
1185
1186 static void get_object_details(void)
1187 {
1188         uint32_t i;
1189         struct object_entry **sorted_by_offset;
1190
1191         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1192         for (i = 0; i < nr_objects; i++)
1193                 sorted_by_offset[i] = objects + i;
1194         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1195
1196         for (i = 0; i < nr_objects; i++)
1197                 check_object(sorted_by_offset[i]);
1198
1199         free(sorted_by_offset);
1200 }
1201
1202 /*
1203  * We search for deltas in a list sorted by type, by filename hash, and then
1204  * by size, so that we see progressively smaller and smaller files.
1205  * That's because we prefer deltas to be from the bigger file
1206  * to the smaller -- deletes are potentially cheaper, but perhaps
1207  * more importantly, the bigger file is likely the more recent
1208  * one.  The deepest deltas are therefore the oldest objects which are
1209  * less susceptible to be accessed often.
1210  */
1211 static int type_size_sort(const void *_a, const void *_b)
1212 {
1213         const struct object_entry *a = *(struct object_entry **)_a;
1214         const struct object_entry *b = *(struct object_entry **)_b;
1215
1216         if (a->type > b->type)
1217                 return -1;
1218         if (a->type < b->type)
1219                 return 1;
1220         if (a->hash > b->hash)
1221                 return -1;
1222         if (a->hash < b->hash)
1223                 return 1;
1224         if (a->preferred_base > b->preferred_base)
1225                 return -1;
1226         if (a->preferred_base < b->preferred_base)
1227                 return 1;
1228         if (a->size > b->size)
1229                 return -1;
1230         if (a->size < b->size)
1231                 return 1;
1232         return a < b ? -1 : (a > b);  /* newest first */
1233 }
1234
1235 struct unpacked {
1236         struct object_entry *entry;
1237         void *data;
1238         struct delta_index *index;
1239         unsigned depth;
1240 };
1241
1242 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1243                            unsigned long delta_size)
1244 {
1245         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1246                 return 0;
1247
1248         if (delta_size < cache_max_small_delta_size)
1249                 return 1;
1250
1251         /* cache delta, if objects are large enough compared to delta size */
1252         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1253                 return 1;
1254
1255         return 0;
1256 }
1257
1258 #ifdef THREADED_DELTA_SEARCH
1259
1260 static pthread_mutex_t read_mutex;
1261 #define read_lock()             pthread_mutex_lock(&read_mutex)
1262 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1263
1264 static pthread_mutex_t cache_mutex;
1265 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1266 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1267
1268 static pthread_mutex_t progress_mutex;
1269 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1270 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1271
1272 #else
1273
1274 #define read_lock()             (void)0
1275 #define read_unlock()           (void)0
1276 #define cache_lock()            (void)0
1277 #define cache_unlock()          (void)0
1278 #define progress_lock()         (void)0
1279 #define progress_unlock()       (void)0
1280
1281 #endif
1282
1283 static int try_delta(struct unpacked *trg, struct unpacked *src,
1284                      unsigned max_depth, unsigned long *mem_usage)
1285 {
1286         struct object_entry *trg_entry = trg->entry;
1287         struct object_entry *src_entry = src->entry;
1288         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1289         unsigned ref_depth;
1290         enum object_type type;
1291         void *delta_buf;
1292
1293         /* Don't bother doing diffs between different types */
1294         if (trg_entry->type != src_entry->type)
1295                 return -1;
1296
1297         /*
1298          * We do not bother to try a delta that we discarded
1299          * on an earlier try, but only when reusing delta data.
1300          */
1301         if (reuse_delta && trg_entry->in_pack &&
1302             trg_entry->in_pack == src_entry->in_pack &&
1303             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1304             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1305                 return 0;
1306
1307         /* Let's not bust the allowed depth. */
1308         if (src->depth >= max_depth)
1309                 return 0;
1310
1311         /* Now some size filtering heuristics. */
1312         trg_size = trg_entry->size;
1313         if (!trg_entry->delta) {
1314                 max_size = trg_size/2 - 20;
1315                 ref_depth = 1;
1316         } else {
1317                 max_size = trg_entry->delta_size;
1318                 ref_depth = trg->depth;
1319         }
1320         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1321                                                 (max_depth - ref_depth + 1);
1322         if (max_size == 0)
1323                 return 0;
1324         src_size = src_entry->size;
1325         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1326         if (sizediff >= max_size)
1327                 return 0;
1328         if (trg_size < src_size / 32)
1329                 return 0;
1330
1331         /* Load data if not already done */
1332         if (!trg->data) {
1333                 read_lock();
1334                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1335                 read_unlock();
1336                 if (!trg->data)
1337                         die("object %s cannot be read",
1338                             sha1_to_hex(trg_entry->idx.sha1));
1339                 if (sz != trg_size)
1340                         die("object %s inconsistent object length (%lu vs %lu)",
1341                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1342                 *mem_usage += sz;
1343         }
1344         if (!src->data) {
1345                 read_lock();
1346                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1347                 read_unlock();
1348                 if (!src->data)
1349                         die("object %s cannot be read",
1350                             sha1_to_hex(src_entry->idx.sha1));
1351                 if (sz != src_size)
1352                         die("object %s inconsistent object length (%lu vs %lu)",
1353                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1354                 *mem_usage += sz;
1355         }
1356         if (!src->index) {
1357                 src->index = create_delta_index(src->data, src_size);
1358                 if (!src->index) {
1359                         static int warned = 0;
1360                         if (!warned++)
1361                                 warning("suboptimal pack - out of memory");
1362                         return 0;
1363                 }
1364                 *mem_usage += sizeof_delta_index(src->index);
1365         }
1366
1367         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1368         if (!delta_buf)
1369                 return 0;
1370
1371         if (trg_entry->delta) {
1372                 /* Prefer only shallower same-sized deltas. */
1373                 if (delta_size == trg_entry->delta_size &&
1374                     src->depth + 1 >= trg->depth) {
1375                         free(delta_buf);
1376                         return 0;
1377                 }
1378         }
1379
1380         /*
1381          * Handle memory allocation outside of the cache
1382          * accounting lock.  Compiler will optimize the strangeness
1383          * away when THREADED_DELTA_SEARCH is not defined.
1384          */
1385         free(trg_entry->delta_data);
1386         cache_lock();
1387         if (trg_entry->delta_data) {
1388                 delta_cache_size -= trg_entry->delta_size;
1389                 trg_entry->delta_data = NULL;
1390         }
1391         if (delta_cacheable(src_size, trg_size, delta_size)) {
1392                 delta_cache_size += delta_size;
1393                 cache_unlock();
1394                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1395         } else {
1396                 cache_unlock();
1397                 free(delta_buf);
1398         }
1399
1400         trg_entry->delta = src_entry;
1401         trg_entry->delta_size = delta_size;
1402         trg->depth = src->depth + 1;
1403
1404         return 1;
1405 }
1406
1407 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1408 {
1409         struct object_entry *child = me->delta_child;
1410         unsigned int m = n;
1411         while (child) {
1412                 unsigned int c = check_delta_limit(child, n + 1);
1413                 if (m < c)
1414                         m = c;
1415                 child = child->delta_sibling;
1416         }
1417         return m;
1418 }
1419
1420 static unsigned long free_unpacked(struct unpacked *n)
1421 {
1422         unsigned long freed_mem = sizeof_delta_index(n->index);
1423         free_delta_index(n->index);
1424         n->index = NULL;
1425         if (n->data) {
1426                 freed_mem += n->entry->size;
1427                 free(n->data);
1428                 n->data = NULL;
1429         }
1430         n->entry = NULL;
1431         n->depth = 0;
1432         return freed_mem;
1433 }
1434
1435 static void find_deltas(struct object_entry **list, unsigned *list_size,
1436                         int window, int depth, unsigned *processed)
1437 {
1438         uint32_t i, idx = 0, count = 0;
1439         struct unpacked *array;
1440         unsigned long mem_usage = 0;
1441
1442         array = xcalloc(window, sizeof(struct unpacked));
1443
1444         for (;;) {
1445                 struct object_entry *entry;
1446                 struct unpacked *n = array + idx;
1447                 int j, max_depth, best_base = -1;
1448
1449                 progress_lock();
1450                 if (!*list_size) {
1451                         progress_unlock();
1452                         break;
1453                 }
1454                 entry = *list++;
1455                 (*list_size)--;
1456                 if (!entry->preferred_base) {
1457                         (*processed)++;
1458                         display_progress(progress_state, *processed);
1459                 }
1460                 progress_unlock();
1461
1462                 mem_usage -= free_unpacked(n);
1463                 n->entry = entry;
1464
1465                 while (window_memory_limit &&
1466                        mem_usage > window_memory_limit &&
1467                        count > 1) {
1468                         uint32_t tail = (idx + window - count) % window;
1469                         mem_usage -= free_unpacked(array + tail);
1470                         count--;
1471                 }
1472
1473                 /* We do not compute delta to *create* objects we are not
1474                  * going to pack.
1475                  */
1476                 if (entry->preferred_base)
1477                         goto next;
1478
1479                 /*
1480                  * If the current object is at pack edge, take the depth the
1481                  * objects that depend on the current object into account
1482                  * otherwise they would become too deep.
1483                  */
1484                 max_depth = depth;
1485                 if (entry->delta_child) {
1486                         max_depth -= check_delta_limit(entry, 0);
1487                         if (max_depth <= 0)
1488                                 goto next;
1489                 }
1490
1491                 j = window;
1492                 while (--j > 0) {
1493                         int ret;
1494                         uint32_t other_idx = idx + j;
1495                         struct unpacked *m;
1496                         if (other_idx >= window)
1497                                 other_idx -= window;
1498                         m = array + other_idx;
1499                         if (!m->entry)
1500                                 break;
1501                         ret = try_delta(n, m, max_depth, &mem_usage);
1502                         if (ret < 0)
1503                                 break;
1504                         else if (ret > 0)
1505                                 best_base = other_idx;
1506                 }
1507
1508                 /*
1509                  * If we decided to cache the delta data, then it is best
1510                  * to compress it right away.  First because we have to do
1511                  * it anyway, and doing it here while we're threaded will
1512                  * save a lot of time in the non threaded write phase,
1513                  * as well as allow for caching more deltas within
1514                  * the same cache size limit.
1515                  * ...
1516                  * But only if not writing to stdout, since in that case
1517                  * the network is most likely throttling writes anyway,
1518                  * and therefore it is best to go to the write phase ASAP
1519                  * instead, as we can afford spending more time compressing
1520                  * between writes at that moment.
1521                  */
1522                 if (entry->delta_data && !pack_to_stdout) {
1523                         entry->z_delta_size = do_compress(&entry->delta_data,
1524                                                           entry->delta_size);
1525                         cache_lock();
1526                         delta_cache_size -= entry->delta_size;
1527                         delta_cache_size += entry->z_delta_size;
1528                         cache_unlock();
1529                 }
1530
1531                 /* if we made n a delta, and if n is already at max
1532                  * depth, leaving it in the window is pointless.  we
1533                  * should evict it first.
1534                  */
1535                 if (entry->delta && max_depth <= n->depth)
1536                         continue;
1537
1538                 /*
1539                  * Move the best delta base up in the window, after the
1540                  * currently deltified object, to keep it longer.  It will
1541                  * be the first base object to be attempted next.
1542                  */
1543                 if (entry->delta) {
1544                         struct unpacked swap = array[best_base];
1545                         int dist = (window + idx - best_base) % window;
1546                         int dst = best_base;
1547                         while (dist--) {
1548                                 int src = (dst + 1) % window;
1549                                 array[dst] = array[src];
1550                                 dst = src;
1551                         }
1552                         array[dst] = swap;
1553                 }
1554
1555                 next:
1556                 idx++;
1557                 if (count + 1 < window)
1558                         count++;
1559                 if (idx >= window)
1560                         idx = 0;
1561         }
1562
1563         for (i = 0; i < window; ++i) {
1564                 free_delta_index(array[i].index);
1565                 free(array[i].data);
1566         }
1567         free(array);
1568 }
1569
1570 #ifdef THREADED_DELTA_SEARCH
1571
1572 /*
1573  * The main thread waits on the condition that (at least) one of the workers
1574  * has stopped working (which is indicated in the .working member of
1575  * struct thread_params).
1576  * When a work thread has completed its work, it sets .working to 0 and
1577  * signals the main thread and waits on the condition that .data_ready
1578  * becomes 1.
1579  */
1580
1581 struct thread_params {
1582         pthread_t thread;
1583         struct object_entry **list;
1584         unsigned list_size;
1585         unsigned remaining;
1586         int window;
1587         int depth;
1588         int working;
1589         int data_ready;
1590         pthread_mutex_t mutex;
1591         pthread_cond_t cond;
1592         unsigned *processed;
1593 };
1594
1595 static pthread_cond_t progress_cond;
1596
1597 /*
1598  * Mutex and conditional variable can't be statically-initialized on Windows.
1599  */
1600 static void init_threaded_search(void)
1601 {
1602         pthread_mutex_init(&read_mutex, NULL);
1603         pthread_mutex_init(&cache_mutex, NULL);
1604         pthread_mutex_init(&progress_mutex, NULL);
1605         pthread_cond_init(&progress_cond, NULL);
1606 }
1607
1608 static void cleanup_threaded_search(void)
1609 {
1610         pthread_cond_destroy(&progress_cond);
1611         pthread_mutex_destroy(&read_mutex);
1612         pthread_mutex_destroy(&cache_mutex);
1613         pthread_mutex_destroy(&progress_mutex);
1614 }
1615
1616 static void *threaded_find_deltas(void *arg)
1617 {
1618         struct thread_params *me = arg;
1619
1620         while (me->remaining) {
1621                 find_deltas(me->list, &me->remaining,
1622                             me->window, me->depth, me->processed);
1623
1624                 progress_lock();
1625                 me->working = 0;
1626                 pthread_cond_signal(&progress_cond);
1627                 progress_unlock();
1628
1629                 /*
1630                  * We must not set ->data_ready before we wait on the
1631                  * condition because the main thread may have set it to 1
1632                  * before we get here. In order to be sure that new
1633                  * work is available if we see 1 in ->data_ready, it
1634                  * was initialized to 0 before this thread was spawned
1635                  * and we reset it to 0 right away.
1636                  */
1637                 pthread_mutex_lock(&me->mutex);
1638                 while (!me->data_ready)
1639                         pthread_cond_wait(&me->cond, &me->mutex);
1640                 me->data_ready = 0;
1641                 pthread_mutex_unlock(&me->mutex);
1642         }
1643         /* leave ->working 1 so that this doesn't get more work assigned */
1644         return NULL;
1645 }
1646
1647 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1648                            int window, int depth, unsigned *processed)
1649 {
1650         struct thread_params *p;
1651         int i, ret, active_threads = 0;
1652
1653         init_threaded_search();
1654
1655         if (!delta_search_threads)      /* --threads=0 means autodetect */
1656                 delta_search_threads = online_cpus();
1657         if (delta_search_threads <= 1) {
1658                 find_deltas(list, &list_size, window, depth, processed);
1659                 cleanup_threaded_search();
1660                 return;
1661         }
1662         if (progress > pack_to_stdout)
1663                 fprintf(stderr, "Delta compression using up to %d threads.\n",
1664                                 delta_search_threads);
1665         p = xcalloc(delta_search_threads, sizeof(*p));
1666
1667         /* Partition the work amongst work threads. */
1668         for (i = 0; i < delta_search_threads; i++) {
1669                 unsigned sub_size = list_size / (delta_search_threads - i);
1670
1671                 /* don't use too small segments or no deltas will be found */
1672                 if (sub_size < 2*window && i+1 < delta_search_threads)
1673                         sub_size = 0;
1674
1675                 p[i].window = window;
1676                 p[i].depth = depth;
1677                 p[i].processed = processed;
1678                 p[i].working = 1;
1679                 p[i].data_ready = 0;
1680
1681                 /* try to split chunks on "path" boundaries */
1682                 while (sub_size && sub_size < list_size &&
1683                        list[sub_size]->hash &&
1684                        list[sub_size]->hash == list[sub_size-1]->hash)
1685                         sub_size++;
1686
1687                 p[i].list = list;
1688                 p[i].list_size = sub_size;
1689                 p[i].remaining = sub_size;
1690
1691                 list += sub_size;
1692                 list_size -= sub_size;
1693         }
1694
1695         /* Start work threads. */
1696         for (i = 0; i < delta_search_threads; i++) {
1697                 if (!p[i].list_size)
1698                         continue;
1699                 pthread_mutex_init(&p[i].mutex, NULL);
1700                 pthread_cond_init(&p[i].cond, NULL);
1701                 ret = pthread_create(&p[i].thread, NULL,
1702                                      threaded_find_deltas, &p[i]);
1703                 if (ret)
1704                         die("unable to create thread: %s", strerror(ret));
1705                 active_threads++;
1706         }
1707
1708         /*
1709          * Now let's wait for work completion.  Each time a thread is done
1710          * with its work, we steal half of the remaining work from the
1711          * thread with the largest number of unprocessed objects and give
1712          * it to that newly idle thread.  This ensure good load balancing
1713          * until the remaining object list segments are simply too short
1714          * to be worth splitting anymore.
1715          */
1716         while (active_threads) {
1717                 struct thread_params *target = NULL;
1718                 struct thread_params *victim = NULL;
1719                 unsigned sub_size = 0;
1720
1721                 progress_lock();
1722                 for (;;) {
1723                         for (i = 0; !target && i < delta_search_threads; i++)
1724                                 if (!p[i].working)
1725                                         target = &p[i];
1726                         if (target)
1727                                 break;
1728                         pthread_cond_wait(&progress_cond, &progress_mutex);
1729                 }
1730
1731                 for (i = 0; i < delta_search_threads; i++)
1732                         if (p[i].remaining > 2*window &&
1733                             (!victim || victim->remaining < p[i].remaining))
1734                                 victim = &p[i];
1735                 if (victim) {
1736                         sub_size = victim->remaining / 2;
1737                         list = victim->list + victim->list_size - sub_size;
1738                         while (sub_size && list[0]->hash &&
1739                                list[0]->hash == list[-1]->hash) {
1740                                 list++;
1741                                 sub_size--;
1742                         }
1743                         if (!sub_size) {
1744                                 /*
1745                                  * It is possible for some "paths" to have
1746                                  * so many objects that no hash boundary
1747                                  * might be found.  Let's just steal the
1748                                  * exact half in that case.
1749                                  */
1750                                 sub_size = victim->remaining / 2;
1751                                 list -= sub_size;
1752                         }
1753                         target->list = list;
1754                         victim->list_size -= sub_size;
1755                         victim->remaining -= sub_size;
1756                 }
1757                 target->list_size = sub_size;
1758                 target->remaining = sub_size;
1759                 target->working = 1;
1760                 progress_unlock();
1761
1762                 pthread_mutex_lock(&target->mutex);
1763                 target->data_ready = 1;
1764                 pthread_cond_signal(&target->cond);
1765                 pthread_mutex_unlock(&target->mutex);
1766
1767                 if (!sub_size) {
1768                         pthread_join(target->thread, NULL);
1769                         pthread_cond_destroy(&target->cond);
1770                         pthread_mutex_destroy(&target->mutex);
1771                         active_threads--;
1772                 }
1773         }
1774         cleanup_threaded_search();
1775         free(p);
1776 }
1777
1778 #else
1779 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1780 #endif
1781
1782 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1783 {
1784         unsigned char peeled[20];
1785
1786         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1787             !peel_ref(path, peeled)        && /* peelable? */
1788             !is_null_sha1(peeled)          && /* annotated tag? */
1789             locate_object_entry(peeled))      /* object packed? */
1790                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1791         return 0;
1792 }
1793
1794 static void prepare_pack(int window, int depth)
1795 {
1796         struct object_entry **delta_list;
1797         uint32_t i, nr_deltas;
1798         unsigned n;
1799
1800         get_object_details();
1801
1802         /*
1803          * If we're locally repacking then we need to be doubly careful
1804          * from now on in order to make sure no stealth corruption gets
1805          * propagated to the new pack.  Clients receiving streamed packs
1806          * should validate everything they get anyway so no need to incur
1807          * the additional cost here in that case.
1808          */
1809         if (!pack_to_stdout)
1810                 do_check_packed_object_crc = 1;
1811
1812         if (!nr_objects || !window || !depth)
1813                 return;
1814
1815         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1816         nr_deltas = n = 0;
1817
1818         for (i = 0; i < nr_objects; i++) {
1819                 struct object_entry *entry = objects + i;
1820
1821                 if (entry->delta)
1822                         /* This happens if we decided to reuse existing
1823                          * delta from a pack.  "reuse_delta &&" is implied.
1824                          */
1825                         continue;
1826
1827                 if (entry->size < 50)
1828                         continue;
1829
1830                 if (entry->no_try_delta)
1831                         continue;
1832
1833                 if (!entry->preferred_base) {
1834                         nr_deltas++;
1835                         if (entry->type < 0)
1836                                 die("unable to get type of object %s",
1837                                     sha1_to_hex(entry->idx.sha1));
1838                 } else {
1839                         if (entry->type < 0) {
1840                                 /*
1841                                  * This object is not found, but we
1842                                  * don't have to include it anyway.
1843                                  */
1844                                 continue;
1845                         }
1846                 }
1847
1848                 delta_list[n++] = entry;
1849         }
1850
1851         if (nr_deltas && n > 1) {
1852                 unsigned nr_done = 0;
1853                 if (progress)
1854                         progress_state = start_progress("Compressing objects",
1855                                                         nr_deltas);
1856                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1857                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1858                 stop_progress(&progress_state);
1859                 if (nr_done != nr_deltas)
1860                         die("inconsistency with delta count");
1861         }
1862         free(delta_list);
1863 }
1864
1865 static int git_pack_config(const char *k, const char *v, void *cb)
1866 {
1867         if (!strcmp(k, "pack.window")) {
1868                 window = git_config_int(k, v);
1869                 return 0;
1870         }
1871         if (!strcmp(k, "pack.windowmemory")) {
1872                 window_memory_limit = git_config_ulong(k, v);
1873                 return 0;
1874         }
1875         if (!strcmp(k, "pack.depth")) {
1876                 depth = git_config_int(k, v);
1877                 return 0;
1878         }
1879         if (!strcmp(k, "pack.compression")) {
1880                 int level = git_config_int(k, v);
1881                 if (level == -1)
1882                         level = Z_DEFAULT_COMPRESSION;
1883                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1884                         die("bad pack compression level %d", level);
1885                 pack_compression_level = level;
1886                 pack_compression_seen = 1;
1887                 return 0;
1888         }
1889         if (!strcmp(k, "pack.deltacachesize")) {
1890                 max_delta_cache_size = git_config_int(k, v);
1891                 return 0;
1892         }
1893         if (!strcmp(k, "pack.deltacachelimit")) {
1894                 cache_max_small_delta_size = git_config_int(k, v);
1895                 return 0;
1896         }
1897         if (!strcmp(k, "pack.threads")) {
1898                 delta_search_threads = git_config_int(k, v);
1899                 if (delta_search_threads < 0)
1900                         die("invalid number of threads specified (%d)",
1901                             delta_search_threads);
1902 #ifndef THREADED_DELTA_SEARCH
1903                 if (delta_search_threads != 1)
1904                         warning("no threads support, ignoring %s", k);
1905 #endif
1906                 return 0;
1907         }
1908         if (!strcmp(k, "pack.indexversion")) {
1909                 pack_idx_default_version = git_config_int(k, v);
1910                 if (pack_idx_default_version > 2)
1911                         die("bad pack.indexversion=%"PRIu32,
1912                                 pack_idx_default_version);
1913                 return 0;
1914         }
1915         if (!strcmp(k, "pack.packsizelimit")) {
1916                 pack_size_limit_cfg = git_config_ulong(k, v);
1917                 return 0;
1918         }
1919         return git_default_config(k, v, cb);
1920 }
1921
1922 static void read_object_list_from_stdin(void)
1923 {
1924         char line[40 + 1 + PATH_MAX + 2];
1925         unsigned char sha1[20];
1926
1927         for (;;) {
1928                 if (!fgets(line, sizeof(line), stdin)) {
1929                         if (feof(stdin))
1930                                 break;
1931                         if (!ferror(stdin))
1932                                 die("fgets returned NULL, not EOF, not error!");
1933                         if (errno != EINTR)
1934                                 die_errno("fgets");
1935                         clearerr(stdin);
1936                         continue;
1937                 }
1938                 if (line[0] == '-') {
1939                         if (get_sha1_hex(line+1, sha1))
1940                                 die("expected edge sha1, got garbage:\n %s",
1941                                     line);
1942                         add_preferred_base(sha1);
1943                         continue;
1944                 }
1945                 if (get_sha1_hex(line, sha1))
1946                         die("expected sha1, got garbage:\n %s", line);
1947
1948                 add_preferred_base_object(line+41);
1949                 add_object_entry(sha1, 0, line+41, 0);
1950         }
1951 }
1952
1953 #define OBJECT_ADDED (1u<<20)
1954
1955 static void show_commit(struct commit *commit, void *data)
1956 {
1957         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1958         commit->object.flags |= OBJECT_ADDED;
1959 }
1960
1961 static void show_object(struct object *obj, const struct name_path *path, const char *last)
1962 {
1963         char *name = path_name(path, last);
1964
1965         add_preferred_base_object(name);
1966         add_object_entry(obj->sha1, obj->type, name, 0);
1967         obj->flags |= OBJECT_ADDED;
1968
1969         /*
1970          * We will have generated the hash from the name,
1971          * but not saved a pointer to it - we can free it
1972          */
1973         free((char *)name);
1974 }
1975
1976 static void show_edge(struct commit *commit)
1977 {
1978         add_preferred_base(commit->object.sha1);
1979 }
1980
1981 struct in_pack_object {
1982         off_t offset;
1983         struct object *object;
1984 };
1985
1986 struct in_pack {
1987         int alloc;
1988         int nr;
1989         struct in_pack_object *array;
1990 };
1991
1992 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1993 {
1994         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1995         in_pack->array[in_pack->nr].object = object;
1996         in_pack->nr++;
1997 }
1998
1999 /*
2000  * Compare the objects in the offset order, in order to emulate the
2001  * "git rev-list --objects" output that produced the pack originally.
2002  */
2003 static int ofscmp(const void *a_, const void *b_)
2004 {
2005         struct in_pack_object *a = (struct in_pack_object *)a_;
2006         struct in_pack_object *b = (struct in_pack_object *)b_;
2007
2008         if (a->offset < b->offset)
2009                 return -1;
2010         else if (a->offset > b->offset)
2011                 return 1;
2012         else
2013                 return hashcmp(a->object->sha1, b->object->sha1);
2014 }
2015
2016 static void add_objects_in_unpacked_packs(struct rev_info *revs)
2017 {
2018         struct packed_git *p;
2019         struct in_pack in_pack;
2020         uint32_t i;
2021
2022         memset(&in_pack, 0, sizeof(in_pack));
2023
2024         for (p = packed_git; p; p = p->next) {
2025                 const unsigned char *sha1;
2026                 struct object *o;
2027
2028                 if (!p->pack_local || p->pack_keep)
2029                         continue;
2030                 if (open_pack_index(p))
2031                         die("cannot open pack index");
2032
2033                 ALLOC_GROW(in_pack.array,
2034                            in_pack.nr + p->num_objects,
2035                            in_pack.alloc);
2036
2037                 for (i = 0; i < p->num_objects; i++) {
2038                         sha1 = nth_packed_object_sha1(p, i);
2039                         o = lookup_unknown_object(sha1);
2040                         if (!(o->flags & OBJECT_ADDED))
2041                                 mark_in_pack_object(o, p, &in_pack);
2042                         o->flags |= OBJECT_ADDED;
2043                 }
2044         }
2045
2046         if (in_pack.nr) {
2047                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
2048                       ofscmp);
2049                 for (i = 0; i < in_pack.nr; i++) {
2050                         struct object *o = in_pack.array[i].object;
2051                         add_object_entry(o->sha1, o->type, "", 0);
2052                 }
2053         }
2054         free(in_pack.array);
2055 }
2056
2057 static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2058 {
2059         static struct packed_git *last_found = (void *)1;
2060         struct packed_git *p;
2061
2062         p = (last_found != (void *)1) ? last_found : packed_git;
2063
2064         while (p) {
2065                 if ((!p->pack_local || p->pack_keep) &&
2066                         find_pack_entry_one(sha1, p)) {
2067                         last_found = p;
2068                         return 1;
2069                 }
2070                 if (p == last_found)
2071                         p = packed_git;
2072                 else
2073                         p = p->next;
2074                 if (p == last_found)
2075                         p = p->next;
2076         }
2077         return 0;
2078 }
2079
2080 static void loosen_unused_packed_objects(struct rev_info *revs)
2081 {
2082         struct packed_git *p;
2083         uint32_t i;
2084         const unsigned char *sha1;
2085
2086         for (p = packed_git; p; p = p->next) {
2087                 if (!p->pack_local || p->pack_keep)
2088                         continue;
2089
2090                 if (open_pack_index(p))
2091                         die("cannot open pack index");
2092
2093                 for (i = 0; i < p->num_objects; i++) {
2094                         sha1 = nth_packed_object_sha1(p, i);
2095                         if (!locate_object_entry(sha1) &&
2096                                 !has_sha1_pack_kept_or_nonlocal(sha1))
2097                                 if (force_object_loose(sha1, p->mtime))
2098                                         die("unable to force loose object");
2099                 }
2100         }
2101 }
2102
2103 static void get_object_list(int ac, const char **av)
2104 {
2105         struct rev_info revs;
2106         char line[1000];
2107         int flags = 0;
2108
2109         init_revisions(&revs, NULL);
2110         save_commit_buffer = 0;
2111         setup_revisions(ac, av, &revs, NULL);
2112
2113         while (fgets(line, sizeof(line), stdin) != NULL) {
2114                 int len = strlen(line);
2115                 if (len && line[len - 1] == '\n')
2116                         line[--len] = 0;
2117                 if (!len)
2118                         break;
2119                 if (*line == '-') {
2120                         if (!strcmp(line, "--not")) {
2121                                 flags ^= UNINTERESTING;
2122                                 continue;
2123                         }
2124                         die("not a rev '%s'", line);
2125                 }
2126                 if (handle_revision_arg(line, &revs, flags, 1))
2127                         die("bad revision '%s'", line);
2128         }
2129
2130         if (prepare_revision_walk(&revs))
2131                 die("revision walk setup failed");
2132         mark_edges_uninteresting(revs.commits, &revs, show_edge);
2133         traverse_commit_list(&revs, show_commit, show_object, NULL);
2134
2135         if (keep_unreachable)
2136                 add_objects_in_unpacked_packs(&revs);
2137         if (unpack_unreachable)
2138                 loosen_unused_packed_objects(&revs);
2139 }
2140
2141 static int adjust_perm(const char *path, mode_t mode)
2142 {
2143         if (chmod(path, mode))
2144                 return -1;
2145         return adjust_shared_perm(path);
2146 }
2147
2148 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2149 {
2150         int use_internal_rev_list = 0;
2151         int thin = 0;
2152         int all_progress_implied = 0;
2153         uint32_t i;
2154         const char **rp_av;
2155         int rp_ac_alloc = 64;
2156         int rp_ac;
2157
2158         read_replace_refs = 0;
2159
2160         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2161
2162         rp_av[0] = "pack-objects";
2163         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2164         rp_ac = 2;
2165
2166         git_config(git_pack_config, NULL);
2167         if (!pack_compression_seen && core_compression_seen)
2168                 pack_compression_level = core_compression_level;
2169
2170         progress = isatty(2);
2171         for (i = 1; i < argc; i++) {
2172                 const char *arg = argv[i];
2173
2174                 if (*arg != '-')
2175                         break;
2176
2177                 if (!strcmp("--non-empty", arg)) {
2178                         non_empty = 1;
2179                         continue;
2180                 }
2181                 if (!strcmp("--local", arg)) {
2182                         local = 1;
2183                         continue;
2184                 }
2185                 if (!strcmp("--incremental", arg)) {
2186                         incremental = 1;
2187                         continue;
2188                 }
2189                 if (!strcmp("--honor-pack-keep", arg)) {
2190                         ignore_packed_keep = 1;
2191                         continue;
2192                 }
2193                 if (!prefixcmp(arg, "--compression=")) {
2194                         char *end;
2195                         int level = strtoul(arg+14, &end, 0);
2196                         if (!arg[14] || *end)
2197                                 usage(pack_usage);
2198                         if (level == -1)
2199                                 level = Z_DEFAULT_COMPRESSION;
2200                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2201                                 die("bad pack compression level %d", level);
2202                         pack_compression_level = level;
2203                         continue;
2204                 }
2205                 if (!prefixcmp(arg, "--max-pack-size=")) {
2206                         char *end;
2207                         pack_size_limit_cfg = 0;
2208                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2209                         if (!arg[16] || *end)
2210                                 usage(pack_usage);
2211                         continue;
2212                 }
2213                 if (!prefixcmp(arg, "--window=")) {
2214                         char *end;
2215                         window = strtoul(arg+9, &end, 0);
2216                         if (!arg[9] || *end)
2217                                 usage(pack_usage);
2218                         continue;
2219                 }
2220                 if (!prefixcmp(arg, "--window-memory=")) {
2221                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2222                                 usage(pack_usage);
2223                         continue;
2224                 }
2225                 if (!prefixcmp(arg, "--threads=")) {
2226                         char *end;
2227                         delta_search_threads = strtoul(arg+10, &end, 0);
2228                         if (!arg[10] || *end || delta_search_threads < 0)
2229                                 usage(pack_usage);
2230 #ifndef THREADED_DELTA_SEARCH
2231                         if (delta_search_threads != 1)
2232                                 warning("no threads support, "
2233                                         "ignoring %s", arg);
2234 #endif
2235                         continue;
2236                 }
2237                 if (!prefixcmp(arg, "--depth=")) {
2238                         char *end;
2239                         depth = strtoul(arg+8, &end, 0);
2240                         if (!arg[8] || *end)
2241                                 usage(pack_usage);
2242                         continue;
2243                 }
2244                 if (!strcmp("--progress", arg)) {
2245                         progress = 1;
2246                         continue;
2247                 }
2248                 if (!strcmp("--all-progress", arg)) {
2249                         progress = 2;
2250                         continue;
2251                 }
2252                 if (!strcmp("--all-progress-implied", arg)) {
2253                         all_progress_implied = 1;
2254                         continue;
2255                 }
2256                 if (!strcmp("-q", arg)) {
2257                         progress = 0;
2258                         continue;
2259                 }
2260                 if (!strcmp("--no-reuse-delta", arg)) {
2261                         reuse_delta = 0;
2262                         continue;
2263                 }
2264                 if (!strcmp("--no-reuse-object", arg)) {
2265                         reuse_object = reuse_delta = 0;
2266                         continue;
2267                 }
2268                 if (!strcmp("--delta-base-offset", arg)) {
2269                         allow_ofs_delta = 1;
2270                         continue;
2271                 }
2272                 if (!strcmp("--stdout", arg)) {
2273                         pack_to_stdout = 1;
2274                         continue;
2275                 }
2276                 if (!strcmp("--revs", arg)) {
2277                         use_internal_rev_list = 1;
2278                         continue;
2279                 }
2280                 if (!strcmp("--keep-unreachable", arg)) {
2281                         keep_unreachable = 1;
2282                         continue;
2283                 }
2284                 if (!strcmp("--unpack-unreachable", arg)) {
2285                         unpack_unreachable = 1;
2286                         continue;
2287                 }
2288                 if (!strcmp("--include-tag", arg)) {
2289                         include_tag = 1;
2290                         continue;
2291                 }
2292                 if (!strcmp("--unpacked", arg) ||
2293                     !strcmp("--reflog", arg) ||
2294                     !strcmp("--all", arg)) {
2295                         use_internal_rev_list = 1;
2296                         if (rp_ac >= rp_ac_alloc - 1) {
2297                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2298                                 rp_av = xrealloc(rp_av,
2299                                                  rp_ac_alloc * sizeof(*rp_av));
2300                         }
2301                         rp_av[rp_ac++] = arg;
2302                         continue;
2303                 }
2304                 if (!strcmp("--thin", arg)) {
2305                         use_internal_rev_list = 1;
2306                         thin = 1;
2307                         rp_av[1] = "--objects-edge";
2308                         continue;
2309                 }
2310                 if (!prefixcmp(arg, "--index-version=")) {
2311                         char *c;
2312                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2313                         if (pack_idx_default_version > 2)
2314                                 die("bad %s", arg);
2315                         if (*c == ',')
2316                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2317                         if (*c || pack_idx_off32_limit & 0x80000000)
2318                                 die("bad %s", arg);
2319                         continue;
2320                 }
2321                 if (!strcmp(arg, "--keep-true-parents")) {
2322                         grafts_replace_parents = 0;
2323                         continue;
2324                 }
2325                 usage(pack_usage);
2326         }
2327
2328         /* Traditionally "pack-objects [options] base extra" failed;
2329          * we would however want to take refs parameter that would
2330          * have been given to upstream rev-list ourselves, which means
2331          * we somehow want to say what the base name is.  So the
2332          * syntax would be:
2333          *
2334          * pack-objects [options] base <refs...>
2335          *
2336          * in other words, we would treat the first non-option as the
2337          * base_name and send everything else to the internal revision
2338          * walker.
2339          */
2340
2341         if (!pack_to_stdout)
2342                 base_name = argv[i++];
2343
2344         if (pack_to_stdout != !base_name)
2345                 usage(pack_usage);
2346
2347         if (!pack_to_stdout && !pack_size_limit)
2348                 pack_size_limit = pack_size_limit_cfg;
2349
2350         if (pack_to_stdout && pack_size_limit)
2351                 die("--max-pack-size cannot be used to build a pack for transfer.");
2352
2353         if (!pack_to_stdout && thin)
2354                 die("--thin cannot be used to build an indexable pack.");
2355
2356         if (keep_unreachable && unpack_unreachable)
2357                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2358
2359         if (progress && all_progress_implied)
2360                 progress = 2;
2361
2362         prepare_packed_git();
2363
2364         if (progress)
2365                 progress_state = start_progress("Counting objects", 0);
2366         if (!use_internal_rev_list)
2367                 read_object_list_from_stdin();
2368         else {
2369                 rp_av[rp_ac] = NULL;
2370                 get_object_list(rp_ac, rp_av);
2371         }
2372         cleanup_preferred_base();
2373         if (include_tag && nr_result)
2374                 for_each_ref(add_ref_tag, NULL);
2375         stop_progress(&progress_state);
2376
2377         if (non_empty && !nr_result)
2378                 return 0;
2379         if (nr_result)
2380                 prepare_pack(window, depth);
2381         write_pack_file();
2382         if (progress)
2383                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2384                         " reused %"PRIu32" (delta %"PRIu32")\n",
2385                         written, written_delta, reused, reused_delta);
2386         return 0;
2387 }