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