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 "csum-file.h"
  12 #include "tree-walk.h"
  13 #include "diff.h"
  14 #include "revision.h"
  15 #include "list-objects.h"
  16 #include "progress.h"
  17
  18 #ifdef THREADED_DELTA_SEARCH
  19 #include <pthread.h>
  20 #endif
  21
  22 static const char pack_usage[] = "\
  23 git-pack-objects [{ -q | --progress | --all-progress }] \n\
  24         [--max-pack-size=N] [--local] [--incremental] \n\
  25         [--window=N] [--window-memory=N] [--depth=N] \n\
  26         [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
  27         [--threads=N] [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
  28         [--stdout | base-name] [--keep-unreachable] [<ref-list | <object-list]";
  29
  30 struct object_entry {
  31         struct pack_idx_entry idx;
  32         unsigned long size;     /* uncompressed size */
  33         struct packed_git *in_pack;     /* already in pack */
  34         off_t in_pack_offset;
  35         struct object_entry *delta;     /* delta base object */
  36         struct object_entry *delta_child; /* deltified objects who bases me */
  37         struct object_entry *delta_sibling; /* other deltified objects who
  38                                              * uses the same base as me
  39                                              */
  40         void *delta_data;       /* cached delta (uncompressed) */
  41         unsigned long delta_size;       /* delta data size (uncompressed) */
  42         unsigned int hash;      /* name hint hash */
  43         enum object_type type;
  44         enum object_type in_pack_type;  /* could be delta */
  45         unsigned char in_pack_header_size;
  46         unsigned char preferred_base; /* we do not pack this, but is available
  47                                        * to be used as the base object to delta
  48                                        * objects against.
  49                                        */
  50         unsigned char no_try_delta;
  51 };
  52
  53 /*
  54  * Objects we are going to pack are collected in objects array (dynamically
  55  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  56  * in the order we see -- typically rev-list --objects order that gives us
  57  * nice "minimum seek" order.
  58  */
  59 static struct object_entry *objects;
  60 static struct object_entry **written_list;
  61 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
  62
  63 static int non_empty;
  64 static int no_reuse_delta, no_reuse_object, keep_unreachable;
  65 static int local;
  66 static int incremental;
  67 static int allow_ofs_delta;
  68 static const char *base_name;
  69 static int progress = 1;
  70 static int window = 10;
  71 static uint32_t pack_size_limit;
  72 static int depth = 50;
  73 static int delta_search_threads = 1;
  74 static int pack_to_stdout;
  75 static int num_preferred_base;
  76 static struct progress *progress_state;
  77 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  78 static int pack_compression_seen;
  79
  80 static unsigned long delta_cache_size = 0;
  81 static unsigned long max_delta_cache_size = 0;
  82 static unsigned long cache_max_small_delta_size = 1000;
  83
  84 static unsigned long window_memory_limit = 0;
  85
  86 /*
  87  * The object names in objects array are hashed with this hashtable,
  88  * to help looking up the entry by object name.
  89  * This hashtable is built after all the objects are seen.
  90  */
  91 static int *object_ix;
  92 static int object_ix_hashsz;
  93
  94 /*
  95  * Pack index for existing packs give us easy access to the offsets into
  96  * corresponding pack file where each object's data starts, but the entries
  97  * do not store the size of the compressed representation (uncompressed
  98  * size is easily available by examining the pack entry header).  It is
  99  * also rather expensive to find the sha1 for an object given its offset.
 100  *
 101  * We build a hashtable of existing packs (pack_revindex), and keep reverse
 102  * index here -- pack index file is sorted by object name mapping to offset;
 103  * this pack_revindex[].revindex array is a list of offset/index_nr pairs
 104  * ordered by offset, so if you know the offset of an object, next offset
 105  * is where its packed representation ends and the index_nr can be used to
 106  * get the object sha1 from the main index.
 107  */
 108 struct revindex_entry {
 109         off_t offset;
 110         unsigned int nr;
 111 };
 112 struct pack_revindex {
 113         struct packed_git *p;
 114         struct revindex_entry *revindex;
 115 };
 116 static struct  pack_revindex *pack_revindex;
 117 static int pack_revindex_hashsz;
 118
 119 /*
 120  * stats
 121  */
 122 static uint32_t written, written_delta;
 123 static uint32_t reused, reused_delta;
 124
 125 static int pack_revindex_ix(struct packed_git *p)
 126 {
 127         unsigned long ui = (unsigned long)p;
 128         int i;
 129
 130         ui = ui ^ (ui >> 16); /* defeat structure alignment */
 131         i = (int)(ui % pack_revindex_hashsz);
 132         while (pack_revindex[i].p) {
 133                 if (pack_revindex[i].p == p)
 134                         return i;
 135                 if (++i == pack_revindex_hashsz)
 136                         i = 0;
 137         }
 138         return -1 - i;
 139 }
 140
 141 static void prepare_pack_ix(void)
 142 {
 143         int num;
 144         struct packed_git *p;
 145         for (num = 0, p = packed_git; p; p = p->next)
 146                 num++;
 147         if (!num)
 148                 return;
 149         pack_revindex_hashsz = num * 11;
 150         pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
 151         for (p = packed_git; p; p = p->next) {
 152                 num = pack_revindex_ix(p);
 153                 num = - 1 - num;
 154                 pack_revindex[num].p = p;
 155         }
 156         /* revindex elements are lazily initialized */
 157 }
 158
 159 static int cmp_offset(const void *a_, const void *b_)
 160 {
 161         const struct revindex_entry *a = a_;
 162         const struct revindex_entry *b = b_;
 163         return (a->offset < b->offset) ? -1 : (a->offset > b->offset) ? 1 : 0;
 164 }
 165
 166 /*
 167  * Ordered list of offsets of objects in the pack.
 168  */
 169 static void prepare_pack_revindex(struct pack_revindex *rix)
 170 {
 171         struct packed_git *p = rix->p;
 172         int num_ent = p->num_objects;
 173         int i;
 174         const char *index = p->index_data;
 175
 176         rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1));
 177         index += 4 * 256;
 178
 179         if (p->index_version > 1) {
 180                 const uint32_t *off_32 =
 181                         (uint32_t *)(index + 8 + p->num_objects * (20 + 4));
 182                 const uint32_t *off_64 = off_32 + p->num_objects;
 183                 for (i = 0; i < num_ent; i++) {
 184                         uint32_t off = ntohl(*off_32++);
 185                         if (!(off & 0x80000000)) {
 186                                 rix->revindex[i].offset = off;
 187                         } else {
 188                                 rix->revindex[i].offset =
 189                                         ((uint64_t)ntohl(*off_64++)) << 32;
 190                                 rix->revindex[i].offset |=
 191                                         ntohl(*off_64++);
 192                         }
 193                         rix->revindex[i].nr = i;
 194                 }
 195         } else {
 196                 for (i = 0; i < num_ent; i++) {
 197                         uint32_t hl = *((uint32_t *)(index + 24 * i));
 198                         rix->revindex[i].offset = ntohl(hl);
 199                         rix->revindex[i].nr = i;
 200                 }
 201         }
 202
 203         /* This knows the pack format -- the 20-byte trailer
 204          * follows immediately after the last object data.
 205          */
 206         rix->revindex[num_ent].offset = p->pack_size - 20;
 207         rix->revindex[num_ent].nr = -1;
 208         qsort(rix->revindex, num_ent, sizeof(*rix->revindex), cmp_offset);
 209 }
 210
 211 static struct revindex_entry * find_packed_object(struct packed_git *p,
 212                                                   off_t ofs)
 213 {
 214         int num;
 215         int lo, hi;
 216         struct pack_revindex *rix;
 217         struct revindex_entry *revindex;
 218         num = pack_revindex_ix(p);
 219         if (num < 0)
 220                 die("internal error: pack revindex uninitialized");
 221         rix = &pack_revindex[num];
 222         if (!rix->revindex)
 223                 prepare_pack_revindex(rix);
 224         revindex = rix->revindex;
 225         lo = 0;
 226         hi = p->num_objects + 1;
 227         do {
 228                 int mi = (lo + hi) / 2;
 229                 if (revindex[mi].offset == ofs) {
 230                         return revindex + mi;
 231                 }
 232                 else if (ofs < revindex[mi].offset)
 233                         hi = mi;
 234                 else
 235                         lo = mi + 1;
 236         } while (lo < hi);
 237         die("internal error: pack revindex corrupt");
 238 }
 239
 240 static const unsigned char *find_packed_object_name(struct packed_git *p,
 241                                                     off_t ofs)
 242 {
 243         struct revindex_entry *entry = find_packed_object(p, ofs);
 244         return nth_packed_object_sha1(p, entry->nr);
 245 }
 246
 247 static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
 248 {
 249         unsigned long othersize, delta_size;
 250         enum object_type type;
 251         void *otherbuf = read_sha1_file(entry->delta->idx.sha1, &type, &othersize);
 252         void *delta_buf;
 253
 254         if (!otherbuf)
 255                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 256         delta_buf = diff_delta(otherbuf, othersize,
 257                                buf, size, &delta_size, 0);
 258         if (!delta_buf || delta_size != entry->delta_size)
 259                 die("delta size changed");
 260         free(buf);
 261         free(otherbuf);
 262         return delta_buf;
 263 }
 264
 265 /*
 266  * The per-object header is a pretty dense thing, which is
 267  *  - first byte: low four bits are "size", then three bits of "type",
 268  *    and the high bit is "size continues".
 269  *  - each byte afterwards: low seven bits are size continuation,
 270  *    with the high bit being "size continues"
 271  */
 272 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 273 {
 274         int n = 1;
 275         unsigned char c;
 276
 277         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 278                 die("bad type %d", type);
 279
 280         c = (type << 4) | (size & 15);
 281         size >>= 4;
 282         while (size) {
 283                 *hdr++ = c | 0x80;
 284                 c = size & 0x7f;
 285                 size >>= 7;
 286                 n++;
 287         }
 288         *hdr = c;
 289         return n;
 290 }
 291
 292 /*
 293  * we are going to reuse the existing object data as is.  make
 294  * sure it is not corrupt.
 295  */
 296 static int check_pack_inflate(struct packed_git *p,
 297                 struct pack_window **w_curs,
 298                 off_t offset,
 299                 off_t len,
 300                 unsigned long expect)
 301 {
 302         z_stream stream;
 303         unsigned char fakebuf[4096], *in;
 304         int st;
 305
 306         memset(&stream, 0, sizeof(stream));
 307         inflateInit(&stream);
 308         do {
 309                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 310                 stream.next_in = in;
 311                 stream.next_out = fakebuf;
 312                 stream.avail_out = sizeof(fakebuf);
 313                 st = inflate(&stream, Z_FINISH);
 314                 offset += stream.next_in - in;
 315         } while (st == Z_OK || st == Z_BUF_ERROR);
 316         inflateEnd(&stream);
 317         return (st == Z_STREAM_END &&
 318                 stream.total_out == expect &&
 319                 stream.total_in == len) ? 0 : -1;
 320 }
 321
 322 static int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
 323                           off_t offset, off_t len, unsigned int nr)
 324 {
 325         const uint32_t *index_crc;
 326         uint32_t data_crc = crc32(0, Z_NULL, 0);
 327
 328         do {
 329                 unsigned int avail;
 330                 void *data = use_pack(p, w_curs, offset, &avail);
 331                 if (avail > len)
 332                         avail = len;
 333                 data_crc = crc32(data_crc, data, avail);
 334                 offset += avail;
 335                 len -= avail;
 336         } while (len);
 337
 338         index_crc = p->index_data;
 339         index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
 340
 341         return data_crc != ntohl(*index_crc);
 342 }
 343
 344 static void copy_pack_data(struct sha1file *f,
 345                 struct packed_git *p,
 346                 struct pack_window **w_curs,
 347                 off_t offset,
 348                 off_t len)
 349 {
 350         unsigned char *in;
 351         unsigned int avail;
 352
 353         while (len) {
 354                 in = use_pack(p, w_curs, offset, &avail);
 355                 if (avail > len)
 356                         avail = (unsigned int)len;
 357                 sha1write(f, in, avail);
 358                 offset += avail;
 359                 len -= avail;
 360         }
 361 }
 362
 363 static unsigned long write_object(struct sha1file *f,
 364                                   struct object_entry *entry,
 365                                   off_t write_offset)
 366 {
 367         unsigned long size;
 368         enum object_type type;
 369         void *buf;
 370         unsigned char header[10];
 371         unsigned char dheader[10];
 372         unsigned hdrlen;
 373         off_t datalen;
 374         enum object_type obj_type;
 375         int to_reuse = 0;
 376         /* write limit if limited packsize and not first object */
 377         unsigned long limit = pack_size_limit && nr_written ?
 378                                 pack_size_limit - write_offset : 0;
 379                                 /* no if no delta */
 380         int usable_delta =      !entry->delta ? 0 :
 381                                 /* yes if unlimited packfile */
 382                                 !pack_size_limit ? 1 :
 383                                 /* no if base written to previous pack */
 384                                 entry->delta->idx.offset == (off_t)-1 ? 0 :
 385                                 /* otherwise double-check written to this
 386                                  * pack,  like we do below
 387                                  */
 388                                 entry->delta->idx.offset ? 1 : 0;
 389
 390         if (!pack_to_stdout)
 391                 crc32_begin(f);
 392
 393         obj_type = entry->type;
 394         if (no_reuse_object)
 395                 to_reuse = 0;   /* explicit */
 396         else if (!entry->in_pack)
 397                 to_reuse = 0;   /* can't reuse what we don't have */
 398         else if (obj_type == OBJ_REF_DELTA || obj_type == OBJ_OFS_DELTA)
 399                                 /* check_object() decided it for us ... */
 400                 to_reuse = usable_delta;
 401                                 /* ... but pack split may override that */
 402         else if (obj_type != entry->in_pack_type)
 403                 to_reuse = 0;   /* pack has delta which is unusable */
 404         else if (entry->delta)
 405                 to_reuse = 0;   /* we want to pack afresh */
 406         else
 407                 to_reuse = 1;   /* we have it in-pack undeltified,
 408                                  * and we do not need to deltify it.
 409                                  */
 410
 411         if (!to_reuse) {
 412                 z_stream stream;
 413                 unsigned long maxsize;
 414                 void *out;
 415                 if (!usable_delta) {
 416                         buf = read_sha1_file(entry->idx.sha1, &obj_type, &size);
 417                         if (!buf)
 418                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 419                 } else if (entry->delta_data) {
 420                         size = entry->delta_size;
 421                         buf = entry->delta_data;
 422                         entry->delta_data = NULL;
 423                         obj_type = (allow_ofs_delta && entry->delta->idx.offset) ?
 424                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 425                 } else {
 426                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 427                         if (!buf)
 428                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 429                         buf = delta_against(buf, size, entry);
 430                         size = entry->delta_size;
 431                         obj_type = (allow_ofs_delta && entry->delta->idx.offset) ?
 432                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 433                 }
 434                 /* compress the data to store and put compressed length in datalen */
 435                 memset(&stream, 0, sizeof(stream));
 436                 deflateInit(&stream, pack_compression_level);
 437                 maxsize = deflateBound(&stream, size);
 438                 out = xmalloc(maxsize);
 439                 /* Compress it */
 440                 stream.next_in = buf;
 441                 stream.avail_in = size;
 442                 stream.next_out = out;
 443                 stream.avail_out = maxsize;
 444                 while (deflate(&stream, Z_FINISH) == Z_OK)
 445                         /* nothing */;
 446                 deflateEnd(&stream);
 447                 datalen = stream.total_out;
 448                 deflateEnd(&stream);
 449                 /*
 450                  * The object header is a byte of 'type' followed by zero or
 451                  * more bytes of length.
 452                  */
 453                 hdrlen = encode_header(obj_type, size, header);
 454
 455                 if (obj_type == OBJ_OFS_DELTA) {
 456                         /*
 457                          * Deltas with relative base contain an additional
 458                          * encoding of the relative offset for the delta
 459                          * base from this object's position in the pack.
 460                          */
 461                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 462                         unsigned pos = sizeof(dheader) - 1;
 463                         dheader[pos] = ofs & 127;
 464                         while (ofs >>= 7)
 465                                 dheader[--pos] = 128 | (--ofs & 127);
 466                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 467                                 free(out);
 468                                 free(buf);
 469                                 return 0;
 470                         }
 471                         sha1write(f, header, hdrlen);
 472                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 473                         hdrlen += sizeof(dheader) - pos;
 474                 } else if (obj_type == OBJ_REF_DELTA) {
 475                         /*
 476                          * Deltas with a base reference contain
 477                          * an additional 20 bytes for the base sha1.
 478                          */
 479                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 480                                 free(out);
 481                                 free(buf);
 482                                 return 0;
 483                         }
 484                         sha1write(f, header, hdrlen);
 485                         sha1write(f, entry->delta->idx.sha1, 20);
 486                         hdrlen += 20;
 487                 } else {
 488                         if (limit && hdrlen + datalen + 20 >= limit) {
 489                                 free(out);
 490                                 free(buf);
 491                                 return 0;
 492                         }
 493                         sha1write(f, header, hdrlen);
 494                 }
 495                 sha1write(f, out, datalen);
 496                 free(out);
 497                 free(buf);
 498         }
 499         else {
 500                 struct packed_git *p = entry->in_pack;
 501                 struct pack_window *w_curs = NULL;
 502                 struct revindex_entry *revidx;
 503                 off_t offset;
 504
 505                 if (entry->delta) {
 506                         obj_type = (allow_ofs_delta && entry->delta->idx.offset) ?
 507                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 508                         reused_delta++;
 509                 }
 510                 hdrlen = encode_header(obj_type, entry->size, header);
 511                 offset = entry->in_pack_offset;
 512                 revidx = find_packed_object(p, offset);
 513                 datalen = revidx[1].offset - offset;
 514                 if (!pack_to_stdout && p->index_version > 1 &&
 515                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
 516                         die("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 517                 offset += entry->in_pack_header_size;
 518                 datalen -= entry->in_pack_header_size;
 519                 if (obj_type == OBJ_OFS_DELTA) {
 520                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 521                         unsigned pos = sizeof(dheader) - 1;
 522                         dheader[pos] = ofs & 127;
 523                         while (ofs >>= 7)
 524                                 dheader[--pos] = 128 | (--ofs & 127);
 525                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit)
 526                                 return 0;
 527                         sha1write(f, header, hdrlen);
 528                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 529                         hdrlen += sizeof(dheader) - pos;
 530                 } else if (obj_type == OBJ_REF_DELTA) {
 531                         if (limit && hdrlen + 20 + datalen + 20 >= limit)
 532                                 return 0;
 533                         sha1write(f, header, hdrlen);
 534                         sha1write(f, entry->delta->idx.sha1, 20);
 535                         hdrlen += 20;
 536                 } else {
 537                         if (limit && hdrlen + datalen + 20 >= limit)
 538                                 return 0;
 539                         sha1write(f, header, hdrlen);
 540                 }
 541
 542                 if (!pack_to_stdout && p->index_version == 1 &&
 543                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
 544                         die("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 545                 copy_pack_data(f, p, &w_curs, offset, datalen);
 546                 unuse_pack(&w_curs);
 547                 reused++;
 548         }
 549         if (usable_delta)
 550                 written_delta++;
 551         written++;
 552         if (!pack_to_stdout)
 553                 entry->idx.crc32 = crc32_end(f);
 554         return hdrlen + datalen;
 555 }
 556
 557 static off_t write_one(struct sha1file *f,
 558                                struct object_entry *e,
 559                                off_t offset)
 560 {
 561         unsigned long size;
 562
 563         /* offset is non zero if object is written already. */
 564         if (e->idx.offset || e->preferred_base)
 565                 return offset;
 566
 567         /* if we are deltified, write out base object first. */
 568         if (e->delta) {
 569                 offset = write_one(f, e->delta, offset);
 570                 if (!offset)
 571                         return 0;
 572         }
 573
 574         e->idx.offset = offset;
 575         size = write_object(f, e, offset);
 576         if (!size) {
 577                 e->idx.offset = 0;
 578                 return 0;
 579         }
 580         written_list[nr_written++] = e;
 581
 582         /* make sure off_t is sufficiently large not to wrap */
 583         if (offset > offset + size)
 584                 die("pack too large for current definition of off_t");
 585         return offset + size;
 586 }
 587
 588 /* forward declaration for write_pack_file */
 589 static int adjust_perm(const char *path, mode_t mode);
 590
 591 static void write_pack_file(void)
 592 {
 593         uint32_t i = 0, j;
 594         struct sha1file *f;
 595         off_t offset, offset_one, last_obj_offset = 0;
 596         struct pack_header hdr;
 597         int do_progress = progress >> pack_to_stdout;
 598         uint32_t nr_remaining = nr_result;
 599
 600         if (do_progress)
 601                 progress_state = start_progress("Writing objects", nr_result);
 602         written_list = xmalloc(nr_objects * sizeof(struct object_entry *));
 603
 604         do {
 605                 unsigned char sha1[20];
 606                 char *pack_tmp_name = NULL;
 607
 608                 if (pack_to_stdout) {
 609                         f = sha1fd(1, "<stdout>");
 610                 } else {
 611                         char tmpname[PATH_MAX];
 612                         int fd;
 613                         snprintf(tmpname, sizeof(tmpname),
 614                                  "%s/tmp_pack_XXXXXX", get_object_directory());
 615                         fd = xmkstemp(tmpname);
 616                         pack_tmp_name = xstrdup(tmpname);
 617                         f = sha1fd(fd, pack_tmp_name);
 618                 }
 619
 620                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
 621                 hdr.hdr_version = htonl(PACK_VERSION);
 622                 hdr.hdr_entries = htonl(nr_remaining);
 623                 sha1write(f, &hdr, sizeof(hdr));
 624                 offset = sizeof(hdr);
 625                 nr_written = 0;
 626                 for (; i < nr_objects; i++) {
 627                         last_obj_offset = offset;
 628                         offset_one = write_one(f, objects + i, offset);
 629                         if (!offset_one)
 630                                 break;
 631                         offset = offset_one;
 632                         display_progress(progress_state, written);
 633                 }
 634
 635                 /*
 636                  * Did we write the wrong # entries in the header?
 637                  * If so, rewrite it like in fast-import
 638                  */
 639                 if (pack_to_stdout || nr_written == nr_remaining) {
 640                         sha1close(f, sha1, 1);
 641                 } else {
 642                         int fd = sha1close(f, NULL, 0);
 643                         fixup_pack_header_footer(fd, sha1, pack_tmp_name, nr_written);
 644                         close(fd);
 645                 }
 646
 647                 if (!pack_to_stdout) {
 648                         mode_t mode = umask(0);
 649                         char *idx_tmp_name, tmpname[PATH_MAX];
 650
 651                         umask(mode);
 652                         mode = 0444 & ~mode;
 653
 654                         idx_tmp_name = write_idx_file(NULL,
 655                                         (struct pack_idx_entry **) written_list,
 656                                         nr_written, sha1);
 657                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 658                                  base_name, sha1_to_hex(sha1));
 659                         if (adjust_perm(pack_tmp_name, mode))
 660                                 die("unable to make temporary pack file readable: %s",
 661                                     strerror(errno));
 662                         if (rename(pack_tmp_name, tmpname))
 663                                 die("unable to rename temporary pack file: %s",
 664                                     strerror(errno));
 665                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 666                                  base_name, sha1_to_hex(sha1));
 667                         if (adjust_perm(idx_tmp_name, mode))
 668                                 die("unable to make temporary index file readable: %s",
 669                                     strerror(errno));
 670                         if (rename(idx_tmp_name, tmpname))
 671                                 die("unable to rename temporary index file: %s",
 672                                     strerror(errno));
 673                         free(idx_tmp_name);
 674                         free(pack_tmp_name);
 675                         puts(sha1_to_hex(sha1));
 676                 }
 677
 678                 /* mark written objects as written to previous pack */
 679                 for (j = 0; j < nr_written; j++) {
 680                         written_list[j]->idx.offset = (off_t)-1;
 681                 }
 682                 nr_remaining -= nr_written;
 683         } while (nr_remaining && i < nr_objects);
 684
 685         free(written_list);
 686         stop_progress(&progress_state);
 687         if (written != nr_result)
 688                 die("wrote %u objects while expecting %u", written, nr_result);
 689         /*
 690          * We have scanned through [0 ... i).  Since we have written
 691          * the correct number of objects,  the remaining [i ... nr_objects)
 692          * items must be either already written (due to out-of-order delta base)
 693          * or a preferred base.  Count those which are neither and complain if any.
 694          */
 695         for (j = 0; i < nr_objects; i++) {
 696                 struct object_entry *e = objects + i;
 697                 j += !e->idx.offset && !e->preferred_base;
 698         }
 699         if (j)
 700                 die("wrote %u objects as expected but %u unwritten", written, j);
 701 }
 702
 703 static int locate_object_entry_hash(const unsigned char *sha1)
 704 {
 705         int i;
 706         unsigned int ui;
 707         memcpy(&ui, sha1, sizeof(unsigned int));
 708         i = ui % object_ix_hashsz;
 709         while (0 < object_ix[i]) {
 710                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 711                         return i;
 712                 if (++i == object_ix_hashsz)
 713                         i = 0;
 714         }
 715         return -1 - i;
 716 }
 717
 718 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 719 {
 720         int i;
 721
 722         if (!object_ix_hashsz)
 723                 return NULL;
 724
 725         i = locate_object_entry_hash(sha1);
 726         if (0 <= i)
 727                 return &objects[object_ix[i]-1];
 728         return NULL;
 729 }
 730
 731 static void rehash_objects(void)
 732 {
 733         uint32_t i;
 734         struct object_entry *oe;
 735
 736         object_ix_hashsz = nr_objects * 3;
 737         if (object_ix_hashsz < 1024)
 738                 object_ix_hashsz = 1024;
 739         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 740         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 741         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 742                 int ix = locate_object_entry_hash(oe->idx.sha1);
 743                 if (0 <= ix)
 744                         continue;
 745                 ix = -1 - ix;
 746                 object_ix[ix] = i + 1;
 747         }
 748 }
 749
 750 static unsigned name_hash(const char *name)
 751 {
 752         unsigned char c;
 753         unsigned hash = 0;
 754
 755         if (!name)
 756                 return 0;
 757
 758         /*
 759          * This effectively just creates a sortable number from the
 760          * last sixteen non-whitespace characters. Last characters
 761          * count "most", so things that end in ".c" sort together.
 762          */
 763         while ((c = *name++) != 0) {
 764                 if (isspace(c))
 765                         continue;
 766                 hash = (hash >> 2) + (c << 24);
 767         }
 768         return hash;
 769 }
 770
 771 static void setup_delta_attr_check(struct git_attr_check *check)
 772 {
 773         static struct git_attr *attr_delta;
 774
 775         if (!attr_delta)
 776                 attr_delta = git_attr("delta", 5);
 777
 778         check[0].attr = attr_delta;
 779 }
 780
 781 static int no_try_delta(const char *path)
 782 {
 783         struct git_attr_check check[1];
 784
 785         setup_delta_attr_check(check);
 786         if (git_checkattr(path, ARRAY_SIZE(check), check))
 787                 return 0;
 788         if (ATTR_FALSE(check->value))
 789                 return 1;
 790         return 0;
 791 }
 792
 793 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 794                             const char *name, int exclude)
 795 {
 796         struct object_entry *entry;
 797         struct packed_git *p, *found_pack = NULL;
 798         off_t found_offset = 0;
 799         int ix;
 800         unsigned hash = name_hash(name);
 801
 802         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 803         if (ix >= 0) {
 804                 if (exclude) {
 805                         entry = objects + object_ix[ix] - 1;
 806                         if (!entry->preferred_base)
 807                                 nr_result--;
 808                         entry->preferred_base = 1;
 809                 }
 810                 return 0;
 811         }
 812
 813         for (p = packed_git; p; p = p->next) {
 814                 off_t offset = find_pack_entry_one(sha1, p);
 815                 if (offset) {
 816                         if (!found_pack) {
 817                                 found_offset = offset;
 818                                 found_pack = p;
 819                         }
 820                         if (exclude)
 821                                 break;
 822                         if (incremental)
 823                                 return 0;
 824                         if (local && !p->pack_local)
 825                                 return 0;
 826                 }
 827         }
 828
 829         if (nr_objects >= nr_alloc) {
 830                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 831                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 832         }
 833
 834         entry = objects + nr_objects++;
 835         memset(entry, 0, sizeof(*entry));
 836         hashcpy(entry->idx.sha1, sha1);
 837         entry->hash = hash;
 838         if (type)
 839                 entry->type = type;
 840         if (exclude)
 841                 entry->preferred_base = 1;
 842         else
 843                 nr_result++;
 844         if (found_pack) {
 845                 entry->in_pack = found_pack;
 846                 entry->in_pack_offset = found_offset;
 847         }
 848
 849         if (object_ix_hashsz * 3 <= nr_objects * 4)
 850                 rehash_objects();
 851         else
 852                 object_ix[-1 - ix] = nr_objects;
 853
 854         display_progress(progress_state, nr_objects);
 855
 856         if (name && no_try_delta(name))
 857                 entry->no_try_delta = 1;
 858
 859         return 1;
 860 }
 861
 862 struct pbase_tree_cache {
 863         unsigned char sha1[20];
 864         int ref;
 865         int temporary;
 866         void *tree_data;
 867         unsigned long tree_size;
 868 };
 869
 870 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 871 static int pbase_tree_cache_ix(const unsigned char *sha1)
 872 {
 873         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 874 }
 875 static int pbase_tree_cache_ix_incr(int ix)
 876 {
 877         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 878 }
 879
 880 static struct pbase_tree {
 881         struct pbase_tree *next;
 882         /* This is a phony "cache" entry; we are not
 883          * going to evict it nor find it through _get()
 884          * mechanism -- this is for the toplevel node that
 885          * would almost always change with any commit.
 886          */
 887         struct pbase_tree_cache pcache;
 888 } *pbase_tree;
 889
 890 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 891 {
 892         struct pbase_tree_cache *ent, *nent;
 893         void *data;
 894         unsigned long size;
 895         enum object_type type;
 896         int neigh;
 897         int my_ix = pbase_tree_cache_ix(sha1);
 898         int available_ix = -1;
 899
 900         /* pbase-tree-cache acts as a limited hashtable.
 901          * your object will be found at your index or within a few
 902          * slots after that slot if it is cached.
 903          */
 904         for (neigh = 0; neigh < 8; neigh++) {
 905                 ent = pbase_tree_cache[my_ix];
 906                 if (ent && !hashcmp(ent->sha1, sha1)) {
 907                         ent->ref++;
 908                         return ent;
 909                 }
 910                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 911                          ((0 <= available_ix) &&
 912                           (!ent && pbase_tree_cache[available_ix])))
 913                         available_ix = my_ix;
 914                 if (!ent)
 915                         break;
 916                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 917         }
 918
 919         /* Did not find one.  Either we got a bogus request or
 920          * we need to read and perhaps cache.
 921          */
 922         data = read_sha1_file(sha1, &type, &size);
 923         if (!data)
 924                 return NULL;
 925         if (type != OBJ_TREE) {
 926                 free(data);
 927                 return NULL;
 928         }
 929
 930         /* We need to either cache or return a throwaway copy */
 931
 932         if (available_ix < 0)
 933                 ent = NULL;
 934         else {
 935                 ent = pbase_tree_cache[available_ix];
 936                 my_ix = available_ix;
 937         }
 938
 939         if (!ent) {
 940                 nent = xmalloc(sizeof(*nent));
 941                 nent->temporary = (available_ix < 0);
 942         }
 943         else {
 944                 /* evict and reuse */
 945                 free(ent->tree_data);
 946                 nent = ent;
 947         }
 948         hashcpy(nent->sha1, sha1);
 949         nent->tree_data = data;
 950         nent->tree_size = size;
 951         nent->ref = 1;
 952         if (!nent->temporary)
 953                 pbase_tree_cache[my_ix] = nent;
 954         return nent;
 955 }
 956
 957 static void pbase_tree_put(struct pbase_tree_cache *cache)
 958 {
 959         if (!cache->temporary) {
 960                 cache->ref--;
 961                 return;
 962         }
 963         free(cache->tree_data);
 964         free(cache);
 965 }
 966
 967 static int name_cmp_len(const char *name)
 968 {
 969         int i;
 970         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 971                 ;
 972         return i;
 973 }
 974
 975 static void add_pbase_object(struct tree_desc *tree,
 976                              const char *name,
 977                              int cmplen,
 978                              const char *fullname)
 979 {
 980         struct name_entry entry;
 981         int cmp;
 982
 983         while (tree_entry(tree,&entry)) {
 984                 if (S_ISGITLINK(entry.mode))
 985                         continue;
 986                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 987                       memcmp(name, entry.path, cmplen);
 988                 if (cmp > 0)
 989                         continue;
 990                 if (cmp < 0)
 991                         return;
 992                 if (name[cmplen] != '/') {
 993                         add_object_entry(entry.sha1,
 994                                          S_ISDIR(entry.mode) ? OBJ_TREE : OBJ_BLOB,
 995                                          fullname, 1);
 996                         return;
 997                 }
 998                 if (S_ISDIR(entry.mode)) {
 999                         struct tree_desc sub;
1000                         struct pbase_tree_cache *tree;
1001                         const char *down = name+cmplen+1;
1002                         int downlen = name_cmp_len(down);
1003
1004                         tree = pbase_tree_get(entry.sha1);
1005                         if (!tree)
1006                                 return;
1007                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1008
1009                         add_pbase_object(&sub, down, downlen, fullname);
1010                         pbase_tree_put(tree);
1011                 }
1012         }
1013 }
1014
1015 static unsigned *done_pbase_paths;
1016 static int done_pbase_paths_num;
1017 static int done_pbase_paths_alloc;
1018 static int done_pbase_path_pos(unsigned hash)
1019 {
1020         int lo = 0;
1021         int hi = done_pbase_paths_num;
1022         while (lo < hi) {
1023                 int mi = (hi + lo) / 2;
1024                 if (done_pbase_paths[mi] == hash)
1025                         return mi;
1026                 if (done_pbase_paths[mi] < hash)
1027                         hi = mi;
1028                 else
1029                         lo = mi + 1;
1030         }
1031         return -lo-1;
1032 }
1033
1034 static int check_pbase_path(unsigned hash)
1035 {
1036         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
1037         if (0 <= pos)
1038                 return 1;
1039         pos = -pos - 1;
1040         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
1041                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
1042                 done_pbase_paths = xrealloc(done_pbase_paths,
1043                                             done_pbase_paths_alloc *
1044                                             sizeof(unsigned));
1045         }
1046         done_pbase_paths_num++;
1047         if (pos < done_pbase_paths_num)
1048                 memmove(done_pbase_paths + pos + 1,
1049                         done_pbase_paths + pos,
1050                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
1051         done_pbase_paths[pos] = hash;
1052         return 0;
1053 }
1054
1055 static void add_preferred_base_object(const char *name)
1056 {
1057         struct pbase_tree *it;
1058         int cmplen;
1059         unsigned hash = name_hash(name);
1060
1061         if (!num_preferred_base || check_pbase_path(hash))
1062                 return;
1063
1064         cmplen = name_cmp_len(name);
1065         for (it = pbase_tree; it; it = it->next) {
1066                 if (cmplen == 0) {
1067                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
1068                 }
1069                 else {
1070                         struct tree_desc tree;
1071                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1072                         add_pbase_object(&tree, name, cmplen, name);
1073                 }
1074         }
1075 }
1076
1077 static void add_preferred_base(unsigned char *sha1)
1078 {
1079         struct pbase_tree *it;
1080         void *data;
1081         unsigned long size;
1082         unsigned char tree_sha1[20];
1083
1084         if (window <= num_preferred_base++)
1085                 return;
1086
1087         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
1088         if (!data)
1089                 return;
1090
1091         for (it = pbase_tree; it; it = it->next) {
1092                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
1093                         free(data);
1094                         return;
1095                 }
1096         }
1097
1098         it = xcalloc(1, sizeof(*it));
1099         it->next = pbase_tree;
1100         pbase_tree = it;
1101
1102         hashcpy(it->pcache.sha1, tree_sha1);
1103         it->pcache.tree_data = data;
1104         it->pcache.tree_size = size;
1105 }
1106
1107 static void check_object(struct object_entry *entry)
1108 {
1109         if (entry->in_pack) {
1110                 struct packed_git *p = entry->in_pack;
1111                 struct pack_window *w_curs = NULL;
1112                 const unsigned char *base_ref = NULL;
1113                 struct object_entry *base_entry;
1114                 unsigned long used, used_0;
1115                 unsigned int avail;
1116                 off_t ofs;
1117                 unsigned char *buf, c;
1118
1119                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1120
1121                 /*
1122                  * We want in_pack_type even if we do not reuse delta
1123                  * since non-delta representations could still be reused.
1124                  */
1125                 used = unpack_object_header_gently(buf, avail,
1126                                                    &entry->in_pack_type,
1127                                                    &entry->size);
1128
1129                 /*
1130                  * Determine if this is a delta and if so whether we can
1131                  * reuse it or not.  Otherwise let's find out as cheaply as
1132                  * possible what the actual type and size for this object is.
1133                  */
1134                 switch (entry->in_pack_type) {
1135                 default:
1136                         /* Not a delta hence we've already got all we need. */
1137                         entry->type = entry->in_pack_type;
1138                         entry->in_pack_header_size = used;
1139                         unuse_pack(&w_curs);
1140                         return;
1141                 case OBJ_REF_DELTA:
1142                         if (!no_reuse_delta && !entry->preferred_base)
1143                                 base_ref = use_pack(p, &w_curs,
1144                                                 entry->in_pack_offset + used, NULL);
1145                         entry->in_pack_header_size = used + 20;
1146                         break;
1147                 case OBJ_OFS_DELTA:
1148                         buf = use_pack(p, &w_curs,
1149                                        entry->in_pack_offset + used, NULL);
1150                         used_0 = 0;
1151                         c = buf[used_0++];
1152                         ofs = c & 127;
1153                         while (c & 128) {
1154                                 ofs += 1;
1155                                 if (!ofs || MSB(ofs, 7))
1156                                         die("delta base offset overflow in pack for %s",
1157                                             sha1_to_hex(entry->idx.sha1));
1158                                 c = buf[used_0++];
1159                                 ofs = (ofs << 7) + (c & 127);
1160                         }
1161                         if (ofs >= entry->in_pack_offset)
1162                                 die("delta base offset out of bound for %s",
1163                                     sha1_to_hex(entry->idx.sha1));
1164                         ofs = entry->in_pack_offset - ofs;
1165                         if (!no_reuse_delta && !entry->preferred_base)
1166                                 base_ref = find_packed_object_name(p, ofs);
1167                         entry->in_pack_header_size = used + used_0;
1168                         break;
1169                 }
1170
1171                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1172                         /*
1173                          * If base_ref was set above that means we wish to
1174                          * reuse delta data, and we even found that base
1175                          * in the list of objects we want to pack. Goodie!
1176                          *
1177                          * Depth value does not matter - find_deltas() will
1178                          * never consider reused delta as the base object to
1179                          * deltify other objects against, in order to avoid
1180                          * circular deltas.
1181                          */
1182                         entry->type = entry->in_pack_type;
1183                         entry->delta = base_entry;
1184                         entry->delta_sibling = base_entry->delta_child;
1185                         base_entry->delta_child = entry;
1186                         unuse_pack(&w_curs);
1187                         return;
1188                 }
1189
1190                 if (entry->type) {
1191                         /*
1192                          * This must be a delta and we already know what the
1193                          * final object type is.  Let's extract the actual
1194                          * object size from the delta header.
1195                          */
1196                         entry->size = get_size_from_delta(p, &w_curs,
1197                                         entry->in_pack_offset + entry->in_pack_header_size);
1198                         unuse_pack(&w_curs);
1199                         return;
1200                 }
1201
1202                 /*
1203                  * No choice but to fall back to the recursive delta walk
1204                  * with sha1_object_info() to find about the object type
1205                  * at this point...
1206                  */
1207                 unuse_pack(&w_curs);
1208         }
1209
1210         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1211         if (entry->type < 0)
1212                 die("unable to get type of object %s",
1213                     sha1_to_hex(entry->idx.sha1));
1214 }
1215
1216 static int pack_offset_sort(const void *_a, const void *_b)
1217 {
1218         const struct object_entry *a = *(struct object_entry **)_a;
1219         const struct object_entry *b = *(struct object_entry **)_b;
1220
1221         /* avoid filesystem trashing with loose objects */
1222         if (!a->in_pack && !b->in_pack)
1223                 return hashcmp(a->idx.sha1, b->idx.sha1);
1224
1225         if (a->in_pack < b->in_pack)
1226                 return -1;
1227         if (a->in_pack > b->in_pack)
1228                 return 1;
1229         return a->in_pack_offset < b->in_pack_offset ? -1 :
1230                         (a->in_pack_offset > b->in_pack_offset);
1231 }
1232
1233 static void get_object_details(void)
1234 {
1235         uint32_t i;
1236         struct object_entry **sorted_by_offset;
1237
1238         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1239         for (i = 0; i < nr_objects; i++)
1240                 sorted_by_offset[i] = objects + i;
1241         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1242
1243         prepare_pack_ix();
1244         for (i = 0; i < nr_objects; i++)
1245                 check_object(sorted_by_offset[i]);
1246         free(sorted_by_offset);
1247 }
1248
1249 static int type_size_sort(const void *_a, const void *_b)
1250 {
1251         const struct object_entry *a = *(struct object_entry **)_a;
1252         const struct object_entry *b = *(struct object_entry **)_b;
1253
1254         if (a->type < b->type)
1255                 return -1;
1256         if (a->type > b->type)
1257                 return 1;
1258         if (a->hash < b->hash)
1259                 return -1;
1260         if (a->hash > b->hash)
1261                 return 1;
1262         if (a->preferred_base < b->preferred_base)
1263                 return -1;
1264         if (a->preferred_base > b->preferred_base)
1265                 return 1;
1266         if (a->size < b->size)
1267                 return -1;
1268         if (a->size > b->size)
1269                 return 1;
1270         return a > b ? -1 : (a < b);  /* newest last */
1271 }
1272
1273 struct unpacked {
1274         struct object_entry *entry;
1275         void *data;
1276         struct delta_index *index;
1277         unsigned depth;
1278 };
1279
1280 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1281                            unsigned long delta_size)
1282 {
1283         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1284                 return 0;
1285
1286         if (delta_size < cache_max_small_delta_size)
1287                 return 1;
1288
1289         /* cache delta, if objects are large enough compared to delta size */
1290         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1291                 return 1;
1292
1293         return 0;
1294 }
1295
1296 #ifdef THREADED_DELTA_SEARCH
1297
1298 static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1299 #define read_lock()             pthread_mutex_lock(&read_mutex)
1300 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1301
1302 static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1303 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1304 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1305
1306 static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1307 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1308 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1309
1310 #else
1311
1312 #define read_lock()             (void)0
1313 #define read_unlock()           (void)0
1314 #define cache_lock()            (void)0
1315 #define cache_unlock()          (void)0
1316 #define progress_lock()         (void)0
1317 #define progress_unlock()       (void)0
1318
1319 #endif
1320
1321 /*
1322  * We search for deltas _backwards_ in a list sorted by type and
1323  * by size, so that we see progressively smaller and smaller files.
1324  * That's because we prefer deltas to be from the bigger file
1325  * to the smaller - deletes are potentially cheaper, but perhaps
1326  * more importantly, the bigger file is likely the more recent
1327  * one.
1328  */
1329 static int try_delta(struct unpacked *trg, struct unpacked *src,
1330                      unsigned max_depth, unsigned long *mem_usage)
1331 {
1332         struct object_entry *trg_entry = trg->entry;
1333         struct object_entry *src_entry = src->entry;
1334         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1335         unsigned ref_depth;
1336         enum object_type type;
1337         void *delta_buf;
1338
1339         /* Don't bother doing diffs between different types */
1340         if (trg_entry->type != src_entry->type)
1341                 return -1;
1342
1343         /*
1344          * We do not bother to try a delta that we discarded
1345          * on an earlier try, but only when reusing delta data.
1346          */
1347         if (!no_reuse_delta && trg_entry->in_pack &&
1348             trg_entry->in_pack == src_entry->in_pack &&
1349             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1350             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1351                 return 0;
1352
1353         /* Let's not bust the allowed depth. */
1354         if (src->depth >= max_depth)
1355                 return 0;
1356
1357         /* Now some size filtering heuristics. */
1358         trg_size = trg_entry->size;
1359         if (!trg_entry->delta) {
1360                 max_size = trg_size/2 - 20;
1361                 ref_depth = 1;
1362         } else {
1363                 max_size = trg_entry->delta_size;
1364                 ref_depth = trg->depth;
1365         }
1366         max_size = max_size * (max_depth - src->depth) /
1367                                                 (max_depth - ref_depth + 1);
1368         if (max_size == 0)
1369                 return 0;
1370         src_size = src_entry->size;
1371         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1372         if (sizediff >= max_size)
1373                 return 0;
1374         if (trg_size < src_size / 32)
1375                 return 0;
1376
1377         /* Load data if not already done */
1378         if (!trg->data) {
1379                 read_lock();
1380                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1381                 read_unlock();
1382                 if (!trg->data)
1383                         die("object %s cannot be read",
1384                             sha1_to_hex(trg_entry->idx.sha1));
1385                 if (sz != trg_size)
1386                         die("object %s inconsistent object length (%lu vs %lu)",
1387                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1388                 *mem_usage += sz;
1389         }
1390         if (!src->data) {
1391                 read_lock();
1392                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1393                 read_unlock();
1394                 if (!src->data)
1395                         die("object %s cannot be read",
1396                             sha1_to_hex(src_entry->idx.sha1));
1397                 if (sz != src_size)
1398                         die("object %s inconsistent object length (%lu vs %lu)",
1399                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1400                 *mem_usage += sz;
1401         }
1402         if (!src->index) {
1403                 src->index = create_delta_index(src->data, src_size);
1404                 if (!src->index) {
1405                         static int warned = 0;
1406                         if (!warned++)
1407                                 warning("suboptimal pack - out of memory");
1408                         return 0;
1409                 }
1410                 *mem_usage += sizeof_delta_index(src->index);
1411         }
1412
1413         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1414         if (!delta_buf)
1415                 return 0;
1416
1417         if (trg_entry->delta) {
1418                 /* Prefer only shallower same-sized deltas. */
1419                 if (delta_size == trg_entry->delta_size &&
1420                     src->depth + 1 >= trg->depth) {
1421                         free(delta_buf);
1422                         return 0;
1423                 }
1424         }
1425
1426         trg_entry->delta = src_entry;
1427         trg_entry->delta_size = delta_size;
1428         trg->depth = src->depth + 1;
1429
1430         /*
1431          * Handle memory allocation outside of the cache
1432          * accounting lock.  Compiler will optimize the strangeness
1433          * away when THREADED_DELTA_SEARCH is not defined.
1434          */
1435         if (trg_entry->delta_data)
1436                 free(trg_entry->delta_data);
1437         cache_lock();
1438         if (trg_entry->delta_data) {
1439                 delta_cache_size -= trg_entry->delta_size;
1440                 trg_entry->delta_data = NULL;
1441         }
1442         if (delta_cacheable(src_size, trg_size, delta_size)) {
1443                 delta_cache_size += trg_entry->delta_size;
1444                 cache_unlock();
1445                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1446         } else {
1447                 cache_unlock();
1448                 free(delta_buf);
1449         }
1450
1451         return 1;
1452 }
1453
1454 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1455 {
1456         struct object_entry *child = me->delta_child;
1457         unsigned int m = n;
1458         while (child) {
1459                 unsigned int c = check_delta_limit(child, n + 1);
1460                 if (m < c)
1461                         m = c;
1462                 child = child->delta_sibling;
1463         }
1464         return m;
1465 }
1466
1467 static unsigned long free_unpacked(struct unpacked *n)
1468 {
1469         unsigned long freed_mem = sizeof_delta_index(n->index);
1470         free_delta_index(n->index);
1471         n->index = NULL;
1472         if (n->data) {
1473                 freed_mem += n->entry->size;
1474                 free(n->data);
1475                 n->data = NULL;
1476         }
1477         n->entry = NULL;
1478         n->depth = 0;
1479         return freed_mem;
1480 }
1481
1482 static void find_deltas(struct object_entry **list, unsigned list_size,
1483                         int window, int depth, unsigned *processed)
1484 {
1485         uint32_t i = list_size, idx = 0, count = 0;
1486         unsigned int array_size = window * sizeof(struct unpacked);
1487         struct unpacked *array;
1488         unsigned long mem_usage = 0;
1489
1490         array = xmalloc(array_size);
1491         memset(array, 0, array_size);
1492
1493         do {
1494                 struct object_entry *entry = list[--i];
1495                 struct unpacked *n = array + idx;
1496                 int j, max_depth, best_base = -1;
1497
1498                 mem_usage -= free_unpacked(n);
1499                 n->entry = entry;
1500
1501                 while (window_memory_limit &&
1502                        mem_usage > window_memory_limit &&
1503                        count > 1) {
1504                         uint32_t tail = (idx + window - count) % window;
1505                         mem_usage -= free_unpacked(array + tail);
1506                         count--;
1507                 }
1508
1509                 /* We do not compute delta to *create* objects we are not
1510                  * going to pack.
1511                  */
1512                 if (entry->preferred_base)
1513                         goto next;
1514
1515                 progress_lock();
1516                 (*processed)++;
1517                 display_progress(progress_state, *processed);
1518                 progress_unlock();
1519
1520                 /*
1521                  * If the current object is at pack edge, take the depth the
1522                  * objects that depend on the current object into account
1523                  * otherwise they would become too deep.
1524                  */
1525                 max_depth = depth;
1526                 if (entry->delta_child) {
1527                         max_depth -= check_delta_limit(entry, 0);
1528                         if (max_depth <= 0)
1529                                 goto next;
1530                 }
1531
1532                 j = window;
1533                 while (--j > 0) {
1534                         int ret;
1535                         uint32_t other_idx = idx + j;
1536                         struct unpacked *m;
1537                         if (other_idx >= window)
1538                                 other_idx -= window;
1539                         m = array + other_idx;
1540                         if (!m->entry)
1541                                 break;
1542                         ret = try_delta(n, m, max_depth, &mem_usage);
1543                         if (ret < 0)
1544                                 break;
1545                         else if (ret > 0)
1546                                 best_base = other_idx;
1547                 }
1548
1549                 /* if we made n a delta, and if n is already at max
1550                  * depth, leaving it in the window is pointless.  we
1551                  * should evict it first.
1552                  */
1553                 if (entry->delta && depth <= n->depth)
1554                         continue;
1555
1556                 /*
1557                  * Move the best delta base up in the window, after the
1558                  * currently deltified object, to keep it longer.  It will
1559                  * be the first base object to be attempted next.
1560                  */
1561                 if (entry->delta) {
1562                         struct unpacked swap = array[best_base];
1563                         int dist = (window + idx - best_base) % window;
1564                         int dst = best_base;
1565                         while (dist--) {
1566                                 int src = (dst + 1) % window;
1567                                 array[dst] = array[src];
1568                                 dst = src;
1569                         }
1570                         array[dst] = swap;
1571                 }
1572
1573                 next:
1574                 idx++;
1575                 if (count + 1 < window)
1576                         count++;
1577                 if (idx >= window)
1578                         idx = 0;
1579         } while (i > 0);
1580
1581         for (i = 0; i < window; ++i) {
1582                 free_delta_index(array[i].index);
1583                 free(array[i].data);
1584         }
1585         free(array);
1586 }
1587
1588 #ifdef THREADED_DELTA_SEARCH
1589
1590 struct thread_params {
1591         pthread_t thread;
1592         struct object_entry **list;
1593         unsigned list_size;
1594         int window;
1595         int depth;
1596         unsigned *processed;
1597 };
1598
1599 static pthread_mutex_t data_request  = PTHREAD_MUTEX_INITIALIZER;
1600 static pthread_mutex_t data_ready    = PTHREAD_MUTEX_INITIALIZER;
1601 static pthread_mutex_t data_provider = PTHREAD_MUTEX_INITIALIZER;
1602 static struct thread_params *data_requester;
1603
1604 static void *threaded_find_deltas(void *arg)
1605 {
1606         struct thread_params *me = arg;
1607
1608         for (;;) {
1609                 pthread_mutex_lock(&data_request);
1610                 data_requester = me;
1611                 pthread_mutex_unlock(&data_provider);
1612                 pthread_mutex_lock(&data_ready);
1613                 pthread_mutex_unlock(&data_request);
1614
1615                 if (!me->list_size)
1616                         return NULL;
1617
1618                 find_deltas(me->list, me->list_size,
1619                             me->window, me->depth, me->processed);
1620         }
1621 }
1622
1623 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1624                            int window, int depth, unsigned *processed)
1625 {
1626         struct thread_params *target, p[delta_search_threads];
1627         int i, ret;
1628         unsigned chunk_size;
1629
1630         if (delta_search_threads <= 1) {
1631                 find_deltas(list, list_size, window, depth, processed);
1632                 return;
1633         }
1634
1635         pthread_mutex_lock(&data_provider);
1636         pthread_mutex_lock(&data_ready);
1637
1638         for (i = 0; i < delta_search_threads; i++) {
1639                 p[i].window = window;
1640                 p[i].depth = depth;
1641                 p[i].processed = processed;
1642                 ret = pthread_create(&p[i].thread, NULL,
1643                                      threaded_find_deltas, &p[i]);
1644                 if (ret)
1645                         die("unable to create thread: %s", strerror(ret));
1646         }
1647
1648         /* this should be auto-tuned somehow */
1649         chunk_size = window * 1000;
1650
1651         do {
1652                 unsigned sublist_size = chunk_size;
1653                 if (sublist_size > list_size)
1654                         sublist_size = list_size;
1655
1656                 /* try to split chunks on "path" boundaries */
1657                 while (sublist_size < list_size && list[sublist_size]->hash &&
1658                        list[sublist_size]->hash == list[sublist_size-1]->hash)
1659                         sublist_size++;
1660
1661                 pthread_mutex_lock(&data_provider);
1662                 target = data_requester;
1663                 target->list = list;
1664                 target->list_size = sublist_size;
1665                 pthread_mutex_unlock(&data_ready);
1666
1667                 list += sublist_size;
1668                 list_size -= sublist_size;
1669                 if (!sublist_size) {
1670                         pthread_join(target->thread, NULL);
1671                         i--;
1672                 }
1673         } while (i);
1674 }
1675
1676 #else
1677 #define ll_find_deltas find_deltas
1678 #endif
1679
1680 static void prepare_pack(int window, int depth)
1681 {
1682         struct object_entry **delta_list;
1683         uint32_t i, n, nr_deltas;
1684
1685         get_object_details();
1686
1687         if (!nr_objects || !window || !depth)
1688                 return;
1689
1690         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1691         nr_deltas = n = 0;
1692
1693         for (i = 0; i < nr_objects; i++) {
1694                 struct object_entry *entry = objects + i;
1695
1696                 if (entry->delta)
1697                         /* This happens if we decided to reuse existing
1698                          * delta from a pack.  "!no_reuse_delta &&" is implied.
1699                          */
1700                         continue;
1701
1702                 if (entry->size < 50)
1703                         continue;
1704
1705                 if (entry->no_try_delta)
1706                         continue;
1707
1708                 if (!entry->preferred_base)
1709                         nr_deltas++;
1710
1711                 delta_list[n++] = entry;
1712         }
1713
1714         if (nr_deltas && n > 1) {
1715                 unsigned nr_done = 0;
1716                 if (progress)
1717                         progress_state = start_progress("Compressing objects",
1718                                                         nr_deltas);
1719                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1720                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1721                 stop_progress(&progress_state);
1722                 if (nr_done != nr_deltas)
1723                         die("inconsistency with delta count");
1724         }
1725         free(delta_list);
1726 }
1727
1728 static int git_pack_config(const char *k, const char *v)
1729 {
1730         if(!strcmp(k, "pack.window")) {
1731                 window = git_config_int(k, v);
1732                 return 0;
1733         }
1734         if (!strcmp(k, "pack.windowmemory")) {
1735                 window_memory_limit = git_config_ulong(k, v);
1736                 return 0;
1737         }
1738         if (!strcmp(k, "pack.depth")) {
1739                 depth = git_config_int(k, v);
1740                 return 0;
1741         }
1742         if (!strcmp(k, "pack.compression")) {
1743                 int level = git_config_int(k, v);
1744                 if (level == -1)
1745                         level = Z_DEFAULT_COMPRESSION;
1746                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1747                         die("bad pack compression level %d", level);
1748                 pack_compression_level = level;
1749                 pack_compression_seen = 1;
1750                 return 0;
1751         }
1752         if (!strcmp(k, "pack.deltacachesize")) {
1753                 max_delta_cache_size = git_config_int(k, v);
1754                 return 0;
1755         }
1756         if (!strcmp(k, "pack.deltacachelimit")) {
1757                 cache_max_small_delta_size = git_config_int(k, v);
1758                 return 0;
1759         }
1760         if (!strcmp(k, "pack.threads")) {
1761                 delta_search_threads = git_config_int(k, v);
1762                 if (delta_search_threads < 1)
1763                         die("invalid number of threads specified (%d)",
1764                             delta_search_threads);
1765 #ifndef THREADED_DELTA_SEARCH
1766                 if (delta_search_threads > 1)
1767                         warning("no threads support, ignoring %s", k);
1768 #endif
1769                 return 0;
1770         }
1771         return git_default_config(k, v);
1772 }
1773
1774 static void read_object_list_from_stdin(void)
1775 {
1776         char line[40 + 1 + PATH_MAX + 2];
1777         unsigned char sha1[20];
1778
1779         for (;;) {
1780                 if (!fgets(line, sizeof(line), stdin)) {
1781                         if (feof(stdin))
1782                                 break;
1783                         if (!ferror(stdin))
1784                                 die("fgets returned NULL, not EOF, not error!");
1785                         if (errno != EINTR)
1786                                 die("fgets: %s", strerror(errno));
1787                         clearerr(stdin);
1788                         continue;
1789                 }
1790                 if (line[0] == '-') {
1791                         if (get_sha1_hex(line+1, sha1))
1792                                 die("expected edge sha1, got garbage:\n %s",
1793                                     line);
1794                         add_preferred_base(sha1);
1795                         continue;
1796                 }
1797                 if (get_sha1_hex(line, sha1))
1798                         die("expected sha1, got garbage:\n %s", line);
1799
1800                 add_preferred_base_object(line+41);
1801                 add_object_entry(sha1, 0, line+41, 0);
1802         }
1803 }
1804
1805 #define OBJECT_ADDED (1u<<20)
1806
1807 static void show_commit(struct commit *commit)
1808 {
1809         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1810         commit->object.flags |= OBJECT_ADDED;
1811 }
1812
1813 static void show_object(struct object_array_entry *p)
1814 {
1815         add_preferred_base_object(p->name);
1816         add_object_entry(p->item->sha1, p->item->type, p->name, 0);
1817         p->item->flags |= OBJECT_ADDED;
1818 }
1819
1820 static void show_edge(struct commit *commit)
1821 {
1822         add_preferred_base(commit->object.sha1);
1823 }
1824
1825 struct in_pack_object {
1826         off_t offset;
1827         struct object *object;
1828 };
1829
1830 struct in_pack {
1831         int alloc;
1832         int nr;
1833         struct in_pack_object *array;
1834 };
1835
1836 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1837 {
1838         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1839         in_pack->array[in_pack->nr].object = object;
1840         in_pack->nr++;
1841 }
1842
1843 /*
1844  * Compare the objects in the offset order, in order to emulate the
1845  * "git-rev-list --objects" output that produced the pack originally.
1846  */
1847 static int ofscmp(const void *a_, const void *b_)
1848 {
1849         struct in_pack_object *a = (struct in_pack_object *)a_;
1850         struct in_pack_object *b = (struct in_pack_object *)b_;
1851
1852         if (a->offset < b->offset)
1853                 return -1;
1854         else if (a->offset > b->offset)
1855                 return 1;
1856         else
1857                 return hashcmp(a->object->sha1, b->object->sha1);
1858 }
1859
1860 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1861 {
1862         struct packed_git *p;
1863         struct in_pack in_pack;
1864         uint32_t i;
1865
1866         memset(&in_pack, 0, sizeof(in_pack));
1867
1868         for (p = packed_git; p; p = p->next) {
1869                 const unsigned char *sha1;
1870                 struct object *o;
1871
1872                 for (i = 0; i < revs->num_ignore_packed; i++) {
1873                         if (matches_pack_name(p, revs->ignore_packed[i]))
1874                                 break;
1875                 }
1876                 if (revs->num_ignore_packed <= i)
1877                         continue;
1878                 if (open_pack_index(p))
1879                         die("cannot open pack index");
1880
1881                 ALLOC_GROW(in_pack.array,
1882                            in_pack.nr + p->num_objects,
1883                            in_pack.alloc);
1884
1885                 for (i = 0; i < p->num_objects; i++) {
1886                         sha1 = nth_packed_object_sha1(p, i);
1887                         o = lookup_unknown_object(sha1);
1888                         if (!(o->flags & OBJECT_ADDED))
1889                                 mark_in_pack_object(o, p, &in_pack);
1890                         o->flags |= OBJECT_ADDED;
1891                 }
1892         }
1893
1894         if (in_pack.nr) {
1895                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
1896                       ofscmp);
1897                 for (i = 0; i < in_pack.nr; i++) {
1898                         struct object *o = in_pack.array[i].object;
1899                         add_object_entry(o->sha1, o->type, "", 0);
1900                 }
1901         }
1902         free(in_pack.array);
1903 }
1904
1905 static void get_object_list(int ac, const char **av)
1906 {
1907         struct rev_info revs;
1908         char line[1000];
1909         int flags = 0;
1910
1911         init_revisions(&revs, NULL);
1912         save_commit_buffer = 0;
1913         track_object_refs = 0;
1914         setup_revisions(ac, av, &revs, NULL);
1915
1916         while (fgets(line, sizeof(line), stdin) != NULL) {
1917                 int len = strlen(line);
1918                 if (line[len - 1] == '\n')
1919                         line[--len] = 0;
1920                 if (!len)
1921                         break;
1922                 if (*line == '-') {
1923                         if (!strcmp(line, "--not")) {
1924                                 flags ^= UNINTERESTING;
1925                                 continue;
1926                         }
1927                         die("not a rev '%s'", line);
1928                 }
1929                 if (handle_revision_arg(line, &revs, flags, 1))
1930                         die("bad revision '%s'", line);
1931         }
1932
1933         prepare_revision_walk(&revs);
1934         mark_edges_uninteresting(revs.commits, &revs, show_edge);
1935         traverse_commit_list(&revs, show_commit, show_object);
1936
1937         if (keep_unreachable)
1938                 add_objects_in_unpacked_packs(&revs);
1939 }
1940
1941 static int adjust_perm(const char *path, mode_t mode)
1942 {
1943         if (chmod(path, mode))
1944                 return -1;
1945         return adjust_shared_perm(path);
1946 }
1947
1948 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
1949 {
1950         int use_internal_rev_list = 0;
1951         int thin = 0;
1952         uint32_t i;
1953         const char **rp_av;
1954         int rp_ac_alloc = 64;
1955         int rp_ac;
1956
1957         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
1958
1959         rp_av[0] = "pack-objects";
1960         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
1961         rp_ac = 2;
1962
1963         git_config(git_pack_config);
1964         if (!pack_compression_seen && core_compression_seen)
1965                 pack_compression_level = core_compression_level;
1966
1967         progress = isatty(2);
1968         for (i = 1; i < argc; i++) {
1969                 const char *arg = argv[i];
1970
1971                 if (*arg != '-')
1972                         break;
1973
1974                 if (!strcmp("--non-empty", arg)) {
1975                         non_empty = 1;
1976                         continue;
1977                 }
1978                 if (!strcmp("--local", arg)) {
1979                         local = 1;
1980                         continue;
1981                 }
1982                 if (!strcmp("--incremental", arg)) {
1983                         incremental = 1;
1984                         continue;
1985                 }
1986                 if (!prefixcmp(arg, "--compression=")) {
1987                         char *end;
1988                         int level = strtoul(arg+14, &end, 0);
1989                         if (!arg[14] || *end)
1990                                 usage(pack_usage);
1991                         if (level == -1)
1992                                 level = Z_DEFAULT_COMPRESSION;
1993                         else if (level < 0 || level > Z_BEST_COMPRESSION)
1994                                 die("bad pack compression level %d", level);
1995                         pack_compression_level = level;
1996                         continue;
1997                 }
1998                 if (!prefixcmp(arg, "--max-pack-size=")) {
1999                         char *end;
2000                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2001                         if (!arg[16] || *end)
2002                                 usage(pack_usage);
2003                         continue;
2004                 }
2005                 if (!prefixcmp(arg, "--window=")) {
2006                         char *end;
2007                         window = strtoul(arg+9, &end, 0);
2008                         if (!arg[9] || *end)
2009                                 usage(pack_usage);
2010                         continue;
2011                 }
2012                 if (!prefixcmp(arg, "--window-memory=")) {
2013                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2014                                 usage(pack_usage);
2015                         continue;
2016                 }
2017                 if (!prefixcmp(arg, "--threads=")) {
2018                         char *end;
2019                         delta_search_threads = strtoul(arg+10, &end, 0);
2020                         if (!arg[10] || *end || delta_search_threads < 1)
2021                                 usage(pack_usage);
2022 #ifndef THREADED_DELTA_SEARCH
2023                         if (delta_search_threads > 1)
2024                                 warning("no threads support, "
2025                                         "ignoring %s", arg);
2026 #endif
2027                         continue;
2028                 }
2029                 if (!prefixcmp(arg, "--depth=")) {
2030                         char *end;
2031                         depth = strtoul(arg+8, &end, 0);
2032                         if (!arg[8] || *end)
2033                                 usage(pack_usage);
2034                         continue;
2035                 }
2036                 if (!strcmp("--progress", arg)) {
2037                         progress = 1;
2038                         continue;
2039                 }
2040                 if (!strcmp("--all-progress", arg)) {
2041                         progress = 2;
2042                         continue;
2043                 }
2044                 if (!strcmp("-q", arg)) {
2045                         progress = 0;
2046                         continue;
2047                 }
2048                 if (!strcmp("--no-reuse-delta", arg)) {
2049                         no_reuse_delta = 1;
2050                         continue;
2051                 }
2052                 if (!strcmp("--no-reuse-object", arg)) {
2053                         no_reuse_object = no_reuse_delta = 1;
2054                         continue;
2055                 }
2056                 if (!strcmp("--delta-base-offset", arg)) {
2057                         allow_ofs_delta = 1;
2058                         continue;
2059                 }
2060                 if (!strcmp("--stdout", arg)) {
2061                         pack_to_stdout = 1;
2062                         continue;
2063                 }
2064                 if (!strcmp("--revs", arg)) {
2065                         use_internal_rev_list = 1;
2066                         continue;
2067                 }
2068                 if (!strcmp("--keep-unreachable", arg)) {
2069                         keep_unreachable = 1;
2070                         continue;
2071                 }
2072                 if (!strcmp("--unpacked", arg) ||
2073                     !prefixcmp(arg, "--unpacked=") ||
2074                     !strcmp("--reflog", arg) ||
2075                     !strcmp("--all", arg)) {
2076                         use_internal_rev_list = 1;
2077                         if (rp_ac >= rp_ac_alloc - 1) {
2078                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2079                                 rp_av = xrealloc(rp_av,
2080                                                  rp_ac_alloc * sizeof(*rp_av));
2081                         }
2082                         rp_av[rp_ac++] = arg;
2083                         continue;
2084                 }
2085                 if (!strcmp("--thin", arg)) {
2086                         use_internal_rev_list = 1;
2087                         thin = 1;
2088                         rp_av[1] = "--objects-edge";
2089                         continue;
2090                 }
2091                 if (!prefixcmp(arg, "--index-version=")) {
2092                         char *c;
2093                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2094                         if (pack_idx_default_version > 2)
2095                                 die("bad %s", arg);
2096                         if (*c == ',')
2097                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2098                         if (*c || pack_idx_off32_limit & 0x80000000)
2099                                 die("bad %s", arg);
2100                         continue;
2101                 }
2102                 usage(pack_usage);
2103         }
2104
2105         /* Traditionally "pack-objects [options] base extra" failed;
2106          * we would however want to take refs parameter that would
2107          * have been given to upstream rev-list ourselves, which means
2108          * we somehow want to say what the base name is.  So the
2109          * syntax would be:
2110          *
2111          * pack-objects [options] base <refs...>
2112          *
2113          * in other words, we would treat the first non-option as the
2114          * base_name and send everything else to the internal revision
2115          * walker.
2116          */
2117
2118         if (!pack_to_stdout)
2119                 base_name = argv[i++];
2120
2121         if (pack_to_stdout != !base_name)
2122                 usage(pack_usage);
2123
2124         if (pack_to_stdout && pack_size_limit)
2125                 die("--max-pack-size cannot be used to build a pack for transfer.");
2126
2127         if (!pack_to_stdout && thin)
2128                 die("--thin cannot be used to build an indexable pack.");
2129
2130         prepare_packed_git();
2131
2132         if (progress)
2133                 progress_state = start_progress("Counting objects", 0);
2134         if (!use_internal_rev_list)
2135                 read_object_list_from_stdin();
2136         else {
2137                 rp_av[rp_ac] = NULL;
2138                 get_object_list(rp_ac, rp_av);
2139         }
2140         stop_progress(&progress_state);
2141
2142         if (non_empty && !nr_result)
2143                 return 0;
2144         if (nr_result)
2145                 prepare_pack(window, depth);
2146         write_pack_file();
2147         if (progress)
2148                 fprintf(stderr, "Total %u (delta %u), reused %u (delta %u)\n",
2149                         written, written_delta, reused, reused_delta);
2150         return 0;
2151 }