builtin-pack-objects.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "attr.h"
   4 #include "object.h"
   5 #include "blob.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "tree.h"
   9 #include "delta.h"
  10 #include "pack.h"
  11 #include "pack-revindex.h"
  12 #include "csum-file.h"
  13 #include "tree-walk.h"
  14 #include "diff.h"
  15 #include "revision.h"
  16 #include "list-objects.h"
  17 #include "progress.h"
  18 #include "refs.h"
  19
  20 #ifdef THREADED_DELTA_SEARCH
  21 #include "thread-utils.h"
  22 #include <pthread.h>
  23 #endif
  24
  25 static const char pack_usage[] = "\
  26 git-pack-objects [{ -q | --progress | --all-progress }] \n\
  27         [--max-pack-size=N] [--local] [--incremental] \n\
  28         [--window=N] [--window-memory=N] [--depth=N] \n\
  29         [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
  30         [--threads=N] [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
  31         [--stdout | base-name] [--include-tag] \n\
  32         [--keep-unreachable | --unpack-unreachable] \n\
  33         [<ref-list | <object-list]";
  34
  35 struct object_entry {
  36         struct pack_idx_entry idx;
  37         unsigned long size;     /* uncompressed size */
  38         struct packed_git *in_pack;     /* already in pack */
  39         off_t in_pack_offset;
  40         struct object_entry *delta;     /* delta base object */
  41         struct object_entry *delta_child; /* deltified objects who bases me */
  42         struct object_entry *delta_sibling; /* other deltified objects who
  43                                              * uses the same base as me
  44                                              */
  45         void *delta_data;       /* cached delta (uncompressed) */
  46         unsigned long delta_size;       /* delta data size (uncompressed) */
  47         unsigned long z_delta_size;     /* delta data size (compressed) */
  48         unsigned int hash;      /* name hint hash */
  49         enum object_type type;
  50         enum object_type in_pack_type;  /* could be delta */
  51         unsigned char in_pack_header_size;
  52         unsigned char preferred_base; /* we do not pack this, but is available
  53                                        * to be used as the base object to delta
  54                                        * objects against.
  55                                        */
  56         unsigned char no_try_delta;
  57 };
  58
  59 /*
  60  * Objects we are going to pack are collected in objects array (dynamically
  61  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  62  * in the order we see -- typically rev-list --objects order that gives us
  63  * nice "minimum seek" order.
  64  */
  65 static struct object_entry *objects;
  66 static struct pack_idx_entry **written_list;
  67 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
  68
  69 static int non_empty;
  70 static int reuse_delta = 1, reuse_object = 1;
  71 static int keep_unreachable, unpack_unreachable, include_tag;
  72 static int local;
  73 static int incremental;
  74 static int allow_ofs_delta;
  75 static const char *base_name;
  76 static int progress = 1;
  77 static int window = 10;
  78 static uint32_t pack_size_limit, pack_size_limit_cfg;
  79 static int depth = 50;
  80 static int delta_search_threads = 1;
  81 static int pack_to_stdout;
  82 static int num_preferred_base;
  83 static struct progress *progress_state;
  84 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  85 static int pack_compression_seen;
  86
  87 static unsigned long delta_cache_size = 0;
  88 static unsigned long max_delta_cache_size = 0;
  89 static unsigned long cache_max_small_delta_size = 1000;
  90
  91 static unsigned long window_memory_limit = 0;
  92
  93 /*
  94  * The object names in objects array are hashed with this hashtable,
  95  * to help looking up the entry by object name.
  96  * This hashtable is built after all the objects are seen.
  97  */
  98 static int *object_ix;
  99 static int object_ix_hashsz;
 100
 101 /*
 102  * stats
 103  */
 104 static uint32_t written, written_delta;
 105 static uint32_t reused, reused_delta;
 106
 107
 108 static void *get_delta(struct object_entry *entry)
 109 {
 110         unsigned long size, base_size, delta_size;
 111         void *buf, *base_buf, *delta_buf;
 112         enum object_type type;
 113
 114         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 115         if (!buf)
 116                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 117         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
 118         if (!base_buf)
 119                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 120         delta_buf = diff_delta(base_buf, base_size,
 121                                buf, size, &delta_size, 0);
 122         if (!delta_buf || delta_size != entry->delta_size)
 123                 die("delta size changed");
 124         free(buf);
 125         free(base_buf);
 126         return delta_buf;
 127 }
 128
 129 static unsigned long do_compress(void **pptr, unsigned long size)
 130 {
 131         z_stream stream;
 132         void *in, *out;
 133         unsigned long maxsize;
 134
 135         memset(&stream, 0, sizeof(stream));
 136         deflateInit(&stream, pack_compression_level);
 137         maxsize = deflateBound(&stream, size);
 138
 139         in = *pptr;
 140         out = xmalloc(maxsize);
 141         *pptr = out;
 142
 143         stream.next_in = in;
 144         stream.avail_in = size;
 145         stream.next_out = out;
 146         stream.avail_out = maxsize;
 147         while (deflate(&stream, Z_FINISH) == Z_OK)
 148                 ; /* nothing */
 149         deflateEnd(&stream);
 150
 151         free(in);
 152         return stream.total_out;
 153 }
 154
 155 /*
 156  * The per-object header is a pretty dense thing, which is
 157  *  - first byte: low four bits are "size", then three bits of "type",
 158  *    and the high bit is "size continues".
 159  *  - each byte afterwards: low seven bits are size continuation,
 160  *    with the high bit being "size continues"
 161  */
 162 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 163 {
 164         int n = 1;
 165         unsigned char c;
 166
 167         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 168                 die("bad type %d", type);
 169
 170         c = (type << 4) | (size & 15);
 171         size >>= 4;
 172         while (size) {
 173                 *hdr++ = c | 0x80;
 174                 c = size & 0x7f;
 175                 size >>= 7;
 176                 n++;
 177         }
 178         *hdr = c;
 179         return n;
 180 }
 181
 182 /*
 183  * we are going to reuse the existing object data as is.  make
 184  * sure it is not corrupt.
 185  */
 186 static int check_pack_inflate(struct packed_git *p,
 187                 struct pack_window **w_curs,
 188                 off_t offset,
 189                 off_t len,
 190                 unsigned long expect)
 191 {
 192         z_stream stream;
 193         unsigned char fakebuf[4096], *in;
 194         int st;
 195
 196         memset(&stream, 0, sizeof(stream));
 197         inflateInit(&stream);
 198         do {
 199                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 200                 stream.next_in = in;
 201                 stream.next_out = fakebuf;
 202                 stream.avail_out = sizeof(fakebuf);
 203                 st = inflate(&stream, Z_FINISH);
 204                 offset += stream.next_in - in;
 205         } while (st == Z_OK || st == Z_BUF_ERROR);
 206         inflateEnd(&stream);
 207         return (st == Z_STREAM_END &&
 208                 stream.total_out == expect &&
 209                 stream.total_in == len) ? 0 : -1;
 210 }
 211
 212 static void copy_pack_data(struct sha1file *f,
 213                 struct packed_git *p,
 214                 struct pack_window **w_curs,
 215                 off_t offset,
 216                 off_t len)
 217 {
 218         unsigned char *in;
 219         unsigned int avail;
 220
 221         while (len) {
 222                 in = use_pack(p, w_curs, offset, &avail);
 223                 if (avail > len)
 224                         avail = (unsigned int)len;
 225                 sha1write(f, in, avail);
 226                 offset += avail;
 227                 len -= avail;
 228         }
 229 }
 230
 231 static unsigned long write_object(struct sha1file *f,
 232                                   struct object_entry *entry,
 233                                   off_t write_offset)
 234 {
 235         unsigned long size, limit, datalen;
 236         void *buf;
 237         unsigned char header[10], dheader[10];
 238         unsigned hdrlen;
 239         enum object_type type;
 240         int usable_delta, to_reuse;
 241
 242         if (!pack_to_stdout)
 243                 crc32_begin(f);
 244
 245         type = entry->type;
 246
 247         /* write limit if limited packsize and not first object */
 248         limit = pack_size_limit && nr_written ?
 249                         pack_size_limit - write_offset : 0;
 250
 251         if (!entry->delta)
 252                 usable_delta = 0;       /* no delta */
 253         else if (!pack_size_limit)
 254                usable_delta = 1;        /* unlimited packfile */
 255         else if (entry->delta->idx.offset == (off_t)-1)
 256                 usable_delta = 0;       /* base was written to another pack */
 257         else if (entry->delta->idx.offset)
 258                 usable_delta = 1;       /* base already exists in this pack */
 259         else
 260                 usable_delta = 0;       /* base could end up in another pack */
 261
 262         if (!reuse_object)
 263                 to_reuse = 0;   /* explicit */
 264         else if (!entry->in_pack)
 265                 to_reuse = 0;   /* can't reuse what we don't have */
 266         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
 267                                 /* check_object() decided it for us ... */
 268                 to_reuse = usable_delta;
 269                                 /* ... but pack split may override that */
 270         else if (type != entry->in_pack_type)
 271                 to_reuse = 0;   /* pack has delta which is unusable */
 272         else if (entry->delta)
 273                 to_reuse = 0;   /* we want to pack afresh */
 274         else
 275                 to_reuse = 1;   /* we have it in-pack undeltified,
 276                                  * and we do not need to deltify it.
 277                                  */
 278
 279         if (!to_reuse) {
 280                 if (!usable_delta) {
 281                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 282                         if (!buf)
 283                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 284                         /*
 285                          * make sure no cached delta data remains from a
 286                          * previous attempt before a pack split occured.
 287                          */
 288                         free(entry->delta_data);
 289                         entry->delta_data = NULL;
 290                         entry->z_delta_size = 0;
 291                 } else if (entry->delta_data) {
 292                         size = entry->delta_size;
 293                         buf = entry->delta_data;
 294                         entry->delta_data = NULL;
 295                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 296                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 297                 } else {
 298                         buf = get_delta(entry);
 299                         size = entry->delta_size;
 300                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 301                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 302                 }
 303
 304                 if (entry->z_delta_size)
 305                         datalen = entry->z_delta_size;
 306                 else
 307                         datalen = do_compress(&buf, size);
 308
 309                 /*
 310                  * The object header is a byte of 'type' followed by zero or
 311                  * more bytes of length.
 312                  */
 313                 hdrlen = encode_header(type, size, header);
 314
 315                 if (type == OBJ_OFS_DELTA) {
 316                         /*
 317                          * Deltas with relative base contain an additional
 318                          * encoding of the relative offset for the delta
 319                          * base from this object's position in the pack.
 320                          */
 321                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 322                         unsigned pos = sizeof(dheader) - 1;
 323                         dheader[pos] = ofs & 127;
 324                         while (ofs >>= 7)
 325                                 dheader[--pos] = 128 | (--ofs & 127);
 326                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 327                                 free(buf);
 328                                 return 0;
 329                         }
 330                         sha1write(f, header, hdrlen);
 331                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 332                         hdrlen += sizeof(dheader) - pos;
 333                 } else if (type == OBJ_REF_DELTA) {
 334                         /*
 335                          * Deltas with a base reference contain
 336                          * an additional 20 bytes for the base sha1.
 337                          */
 338                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 339                                 free(buf);
 340                                 return 0;
 341                         }
 342                         sha1write(f, header, hdrlen);
 343                         sha1write(f, entry->delta->idx.sha1, 20);
 344                         hdrlen += 20;
 345                 } else {
 346                         if (limit && hdrlen + datalen + 20 >= limit) {
 347                                 free(buf);
 348                                 return 0;
 349                         }
 350                         sha1write(f, header, hdrlen);
 351                 }
 352                 sha1write(f, buf, datalen);
 353                 free(buf);
 354         }
 355         else {
 356                 struct packed_git *p = entry->in_pack;
 357                 struct pack_window *w_curs = NULL;
 358                 struct revindex_entry *revidx;
 359                 off_t offset;
 360
 361                 if (entry->delta) {
 362                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 363                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 364                         reused_delta++;
 365                 }
 366                 hdrlen = encode_header(type, entry->size, header);
 367                 offset = entry->in_pack_offset;
 368                 revidx = find_pack_revindex(p, offset);
 369                 datalen = revidx[1].offset - offset;
 370                 if (!pack_to_stdout && p->index_version > 1 &&
 371                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
 372                         die("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 373                 offset += entry->in_pack_header_size;
 374                 datalen -= entry->in_pack_header_size;
 375                 if (type == OBJ_OFS_DELTA) {
 376                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 377                         unsigned pos = sizeof(dheader) - 1;
 378                         dheader[pos] = ofs & 127;
 379                         while (ofs >>= 7)
 380                                 dheader[--pos] = 128 | (--ofs & 127);
 381                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit)
 382                                 return 0;
 383                         sha1write(f, header, hdrlen);
 384                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 385                         hdrlen += sizeof(dheader) - pos;
 386                 } else if (type == OBJ_REF_DELTA) {
 387                         if (limit && hdrlen + 20 + datalen + 20 >= limit)
 388                                 return 0;
 389                         sha1write(f, header, hdrlen);
 390                         sha1write(f, entry->delta->idx.sha1, 20);
 391                         hdrlen += 20;
 392                 } else {
 393                         if (limit && hdrlen + datalen + 20 >= limit)
 394                                 return 0;
 395                         sha1write(f, header, hdrlen);
 396                 }
 397
 398                 if (!pack_to_stdout && p->index_version == 1 &&
 399                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
 400                         die("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 401                 copy_pack_data(f, p, &w_curs, offset, datalen);
 402                 unuse_pack(&w_curs);
 403                 reused++;
 404         }
 405         if (usable_delta)
 406                 written_delta++;
 407         written++;
 408         if (!pack_to_stdout)
 409                 entry->idx.crc32 = crc32_end(f);
 410         return hdrlen + datalen;
 411 }
 412
 413 static off_t write_one(struct sha1file *f,
 414                                struct object_entry *e,
 415                                off_t offset)
 416 {
 417         unsigned long size;
 418
 419         /* offset is non zero if object is written already. */
 420         if (e->idx.offset || e->preferred_base)
 421                 return offset;
 422
 423         /* if we are deltified, write out base object first. */
 424         if (e->delta) {
 425                 offset = write_one(f, e->delta, offset);
 426                 if (!offset)
 427                         return 0;
 428         }
 429
 430         e->idx.offset = offset;
 431         size = write_object(f, e, offset);
 432         if (!size) {
 433                 e->idx.offset = 0;
 434                 return 0;
 435         }
 436         written_list[nr_written++] = &e->idx;
 437
 438         /* make sure off_t is sufficiently large not to wrap */
 439         if (offset > offset + size)
 440                 die("pack too large for current definition of off_t");
 441         return offset + size;
 442 }
 443
 444 /* forward declaration for write_pack_file */
 445 static int adjust_perm(const char *path, mode_t mode);
 446
 447 static void write_pack_file(void)
 448 {
 449         uint32_t i = 0, j;
 450         struct sha1file *f;
 451         off_t offset, offset_one, last_obj_offset = 0;
 452         struct pack_header hdr;
 453         uint32_t nr_remaining = nr_result;
 454         time_t last_mtime = 0;
 455
 456         if (progress > pack_to_stdout)
 457                 progress_state = start_progress("Writing objects", nr_result);
 458         written_list = xmalloc(nr_objects * sizeof(*written_list));
 459
 460         do {
 461                 unsigned char sha1[20];
 462                 char *pack_tmp_name = NULL;
 463
 464                 if (pack_to_stdout) {
 465                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 466                 } else {
 467                         char tmpname[PATH_MAX];
 468                         int fd;
 469                         snprintf(tmpname, sizeof(tmpname),
 470                                  "%s/tmp_pack_XXXXXX", get_object_directory());
 471                         fd = xmkstemp(tmpname);
 472                         pack_tmp_name = xstrdup(tmpname);
 473                         f = sha1fd(fd, pack_tmp_name);
 474                 }
 475
 476                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
 477                 hdr.hdr_version = htonl(PACK_VERSION);
 478                 hdr.hdr_entries = htonl(nr_remaining);
 479                 sha1write(f, &hdr, sizeof(hdr));
 480                 offset = sizeof(hdr);
 481                 nr_written = 0;
 482                 for (; i < nr_objects; i++) {
 483                         last_obj_offset = offset;
 484                         offset_one = write_one(f, objects + i, offset);
 485                         if (!offset_one)
 486                                 break;
 487                         offset = offset_one;
 488                         display_progress(progress_state, written);
 489                 }
 490
 491                 /*
 492                  * Did we write the wrong # entries in the header?
 493                  * If so, rewrite it like in fast-import
 494                  */
 495                 if (pack_to_stdout) {
 496                         sha1close(f, sha1, CSUM_CLOSE);
 497                 } else if (nr_written == nr_remaining) {
 498                         sha1close(f, sha1, CSUM_FSYNC);
 499                 } else {
 500                         int fd = sha1close(f, NULL, 0);
 501                         fixup_pack_header_footer(fd, sha1, pack_tmp_name, nr_written);
 502                         close(fd);
 503                 }
 504
 505                 if (!pack_to_stdout) {
 506                         mode_t mode = umask(0);
 507                         struct stat st;
 508                         char *idx_tmp_name, tmpname[PATH_MAX];
 509
 510                         umask(mode);
 511                         mode = 0444 & ~mode;
 512
 513                         idx_tmp_name = write_idx_file(NULL, written_list,
 514                                                       nr_written, sha1);
 515
 516                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 517                                  base_name, sha1_to_hex(sha1));
 518                         if (adjust_perm(pack_tmp_name, mode))
 519                                 die("unable to make temporary pack file readable: %s",
 520                                     strerror(errno));
 521                         if (rename(pack_tmp_name, tmpname))
 522                                 die("unable to rename temporary pack file: %s",
 523                                     strerror(errno));
 524
 525                         /*
 526                          * Packs are runtime accessed in their mtime
 527                          * order since newer packs are more likely to contain
 528                          * younger objects.  So if we are creating multiple
 529                          * packs then we should modify the mtime of later ones
 530                          * to preserve this property.
 531                          */
 532                         if (stat(tmpname, &st) < 0) {
 533                                 warning("failed to stat %s: %s",
 534                                         tmpname, strerror(errno));
 535                         } else if (!last_mtime) {
 536                                 last_mtime = st.st_mtime;
 537                         } else {
 538                                 struct utimbuf utb;
 539                                 utb.actime = st.st_atime;
 540                                 utb.modtime = --last_mtime;
 541                                 if (utime(tmpname, &utb) < 0)
 542                                         warning("failed utime() on %s: %s",
 543                                                 tmpname, strerror(errno));
 544                         }
 545
 546                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 547                                  base_name, sha1_to_hex(sha1));
 548                         if (adjust_perm(idx_tmp_name, mode))
 549                                 die("unable to make temporary index file readable: %s",
 550                                     strerror(errno));
 551                         if (rename(idx_tmp_name, tmpname))
 552                                 die("unable to rename temporary index file: %s",
 553                                     strerror(errno));
 554
 555                         free(idx_tmp_name);
 556                         free(pack_tmp_name);
 557                         puts(sha1_to_hex(sha1));
 558                 }
 559
 560                 /* mark written objects as written to previous pack */
 561                 for (j = 0; j < nr_written; j++) {
 562                         written_list[j]->offset = (off_t)-1;
 563                 }
 564                 nr_remaining -= nr_written;
 565         } while (nr_remaining && i < nr_objects);
 566
 567         free(written_list);
 568         stop_progress(&progress_state);
 569         if (written != nr_result)
 570                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
 571                         written, nr_result);
 572         /*
 573          * We have scanned through [0 ... i).  Since we have written
 574          * the correct number of objects,  the remaining [i ... nr_objects)
 575          * items must be either already written (due to out-of-order delta base)
 576          * or a preferred base.  Count those which are neither and complain if any.
 577          */
 578         for (j = 0; i < nr_objects; i++) {
 579                 struct object_entry *e = objects + i;
 580                 j += !e->idx.offset && !e->preferred_base;
 581         }
 582         if (j)
 583                 die("wrote %"PRIu32" objects as expected but %"PRIu32
 584                         " unwritten", written, j);
 585 }
 586
 587 static int locate_object_entry_hash(const unsigned char *sha1)
 588 {
 589         int i;
 590         unsigned int ui;
 591         memcpy(&ui, sha1, sizeof(unsigned int));
 592         i = ui % object_ix_hashsz;
 593         while (0 < object_ix[i]) {
 594                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 595                         return i;
 596                 if (++i == object_ix_hashsz)
 597                         i = 0;
 598         }
 599         return -1 - i;
 600 }
 601
 602 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 603 {
 604         int i;
 605
 606         if (!object_ix_hashsz)
 607                 return NULL;
 608
 609         i = locate_object_entry_hash(sha1);
 610         if (0 <= i)
 611                 return &objects[object_ix[i]-1];
 612         return NULL;
 613 }
 614
 615 static void rehash_objects(void)
 616 {
 617         uint32_t i;
 618         struct object_entry *oe;
 619
 620         object_ix_hashsz = nr_objects * 3;
 621         if (object_ix_hashsz < 1024)
 622                 object_ix_hashsz = 1024;
 623         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 624         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 625         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 626                 int ix = locate_object_entry_hash(oe->idx.sha1);
 627                 if (0 <= ix)
 628                         continue;
 629                 ix = -1 - ix;
 630                 object_ix[ix] = i + 1;
 631         }
 632 }
 633
 634 static unsigned name_hash(const char *name)
 635 {
 636         unsigned char c;
 637         unsigned hash = 0;
 638
 639         if (!name)
 640                 return 0;
 641
 642         /*
 643          * This effectively just creates a sortable number from the
 644          * last sixteen non-whitespace characters. Last characters
 645          * count "most", so things that end in ".c" sort together.
 646          */
 647         while ((c = *name++) != 0) {
 648                 if (isspace(c))
 649                         continue;
 650                 hash = (hash >> 2) + (c << 24);
 651         }
 652         return hash;
 653 }
 654
 655 static void setup_delta_attr_check(struct git_attr_check *check)
 656 {
 657         static struct git_attr *attr_delta;
 658
 659         if (!attr_delta)
 660                 attr_delta = git_attr("delta", 5);
 661
 662         check[0].attr = attr_delta;
 663 }
 664
 665 static int no_try_delta(const char *path)
 666 {
 667         struct git_attr_check check[1];
 668
 669         setup_delta_attr_check(check);
 670         if (git_checkattr(path, ARRAY_SIZE(check), check))
 671                 return 0;
 672         if (ATTR_FALSE(check->value))
 673                 return 1;
 674         return 0;
 675 }
 676
 677 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 678                             const char *name, int exclude)
 679 {
 680         struct object_entry *entry;
 681         struct packed_git *p, *found_pack = NULL;
 682         off_t found_offset = 0;
 683         int ix;
 684         unsigned hash = name_hash(name);
 685
 686         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 687         if (ix >= 0) {
 688                 if (exclude) {
 689                         entry = objects + object_ix[ix] - 1;
 690                         if (!entry->preferred_base)
 691                                 nr_result--;
 692                         entry->preferred_base = 1;
 693                 }
 694                 return 0;
 695         }
 696
 697         for (p = packed_git; p; p = p->next) {
 698                 off_t offset = find_pack_entry_one(sha1, p);
 699                 if (offset) {
 700                         if (!found_pack) {
 701                                 found_offset = offset;
 702                                 found_pack = p;
 703                         }
 704                         if (exclude)
 705                                 break;
 706                         if (incremental)
 707                                 return 0;
 708                         if (local && !p->pack_local)
 709                                 return 0;
 710                 }
 711         }
 712
 713         if (nr_objects >= nr_alloc) {
 714                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 715                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 716         }
 717
 718         entry = objects + nr_objects++;
 719         memset(entry, 0, sizeof(*entry));
 720         hashcpy(entry->idx.sha1, sha1);
 721         entry->hash = hash;
 722         if (type)
 723                 entry->type = type;
 724         if (exclude)
 725                 entry->preferred_base = 1;
 726         else
 727                 nr_result++;
 728         if (found_pack) {
 729                 entry->in_pack = found_pack;
 730                 entry->in_pack_offset = found_offset;
 731         }
 732
 733         if (object_ix_hashsz * 3 <= nr_objects * 4)
 734                 rehash_objects();
 735         else
 736                 object_ix[-1 - ix] = nr_objects;
 737
 738         display_progress(progress_state, nr_objects);
 739
 740         if (name && no_try_delta(name))
 741                 entry->no_try_delta = 1;
 742
 743         return 1;
 744 }
 745
 746 struct pbase_tree_cache {
 747         unsigned char sha1[20];
 748         int ref;
 749         int temporary;
 750         void *tree_data;
 751         unsigned long tree_size;
 752 };
 753
 754 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 755 static int pbase_tree_cache_ix(const unsigned char *sha1)
 756 {
 757         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 758 }
 759 static int pbase_tree_cache_ix_incr(int ix)
 760 {
 761         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 762 }
 763
 764 static struct pbase_tree {
 765         struct pbase_tree *next;
 766         /* This is a phony "cache" entry; we are not
 767          * going to evict it nor find it through _get()
 768          * mechanism -- this is for the toplevel node that
 769          * would almost always change with any commit.
 770          */
 771         struct pbase_tree_cache pcache;
 772 } *pbase_tree;
 773
 774 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 775 {
 776         struct pbase_tree_cache *ent, *nent;
 777         void *data;
 778         unsigned long size;
 779         enum object_type type;
 780         int neigh;
 781         int my_ix = pbase_tree_cache_ix(sha1);
 782         int available_ix = -1;
 783
 784         /* pbase-tree-cache acts as a limited hashtable.
 785          * your object will be found at your index or within a few
 786          * slots after that slot if it is cached.
 787          */
 788         for (neigh = 0; neigh < 8; neigh++) {
 789                 ent = pbase_tree_cache[my_ix];
 790                 if (ent && !hashcmp(ent->sha1, sha1)) {
 791                         ent->ref++;
 792                         return ent;
 793                 }
 794                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 795                          ((0 <= available_ix) &&
 796                           (!ent && pbase_tree_cache[available_ix])))
 797                         available_ix = my_ix;
 798                 if (!ent)
 799                         break;
 800                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 801         }
 802
 803         /* Did not find one.  Either we got a bogus request or
 804          * we need to read and perhaps cache.
 805          */
 806         data = read_sha1_file(sha1, &type, &size);
 807         if (!data)
 808                 return NULL;
 809         if (type != OBJ_TREE) {
 810                 free(data);
 811                 return NULL;
 812         }
 813
 814         /* We need to either cache or return a throwaway copy */
 815
 816         if (available_ix < 0)
 817                 ent = NULL;
 818         else {
 819                 ent = pbase_tree_cache[available_ix];
 820                 my_ix = available_ix;
 821         }
 822
 823         if (!ent) {
 824                 nent = xmalloc(sizeof(*nent));
 825                 nent->temporary = (available_ix < 0);
 826         }
 827         else {
 828                 /* evict and reuse */
 829                 free(ent->tree_data);
 830                 nent = ent;
 831         }
 832         hashcpy(nent->sha1, sha1);
 833         nent->tree_data = data;
 834         nent->tree_size = size;
 835         nent->ref = 1;
 836         if (!nent->temporary)
 837                 pbase_tree_cache[my_ix] = nent;
 838         return nent;
 839 }
 840
 841 static void pbase_tree_put(struct pbase_tree_cache *cache)
 842 {
 843         if (!cache->temporary) {
 844                 cache->ref--;
 845                 return;
 846         }
 847         free(cache->tree_data);
 848         free(cache);
 849 }
 850
 851 static int name_cmp_len(const char *name)
 852 {
 853         int i;
 854         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 855                 ;
 856         return i;
 857 }
 858
 859 static void add_pbase_object(struct tree_desc *tree,
 860                              const char *name,
 861                              int cmplen,
 862                              const char *fullname)
 863 {
 864         struct name_entry entry;
 865         int cmp;
 866
 867         while (tree_entry(tree,&entry)) {
 868                 if (S_ISGITLINK(entry.mode))
 869                         continue;
 870                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 871                       memcmp(name, entry.path, cmplen);
 872                 if (cmp > 0)
 873                         continue;
 874                 if (cmp < 0)
 875                         return;
 876                 if (name[cmplen] != '/') {
 877                         add_object_entry(entry.sha1,
 878                                          object_type(entry.mode),
 879                                          fullname, 1);
 880                         return;
 881                 }
 882                 if (S_ISDIR(entry.mode)) {
 883                         struct tree_desc sub;
 884                         struct pbase_tree_cache *tree;
 885                         const char *down = name+cmplen+1;
 886                         int downlen = name_cmp_len(down);
 887
 888                         tree = pbase_tree_get(entry.sha1);
 889                         if (!tree)
 890                                 return;
 891                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 892
 893                         add_pbase_object(&sub, down, downlen, fullname);
 894                         pbase_tree_put(tree);
 895                 }
 896         }
 897 }
 898
 899 static unsigned *done_pbase_paths;
 900 static int done_pbase_paths_num;
 901 static int done_pbase_paths_alloc;
 902 static int done_pbase_path_pos(unsigned hash)
 903 {
 904         int lo = 0;
 905         int hi = done_pbase_paths_num;
 906         while (lo < hi) {
 907                 int mi = (hi + lo) / 2;
 908                 if (done_pbase_paths[mi] == hash)
 909                         return mi;
 910                 if (done_pbase_paths[mi] < hash)
 911                         hi = mi;
 912                 else
 913                         lo = mi + 1;
 914         }
 915         return -lo-1;
 916 }
 917
 918 static int check_pbase_path(unsigned hash)
 919 {
 920         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 921         if (0 <= pos)
 922                 return 1;
 923         pos = -pos - 1;
 924         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 925                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 926                 done_pbase_paths = xrealloc(done_pbase_paths,
 927                                             done_pbase_paths_alloc *
 928                                             sizeof(unsigned));
 929         }
 930         done_pbase_paths_num++;
 931         if (pos < done_pbase_paths_num)
 932                 memmove(done_pbase_paths + pos + 1,
 933                         done_pbase_paths + pos,
 934                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 935         done_pbase_paths[pos] = hash;
 936         return 0;
 937 }
 938
 939 static void add_preferred_base_object(const char *name)
 940 {
 941         struct pbase_tree *it;
 942         int cmplen;
 943         unsigned hash = name_hash(name);
 944
 945         if (!num_preferred_base || check_pbase_path(hash))
 946                 return;
 947
 948         cmplen = name_cmp_len(name);
 949         for (it = pbase_tree; it; it = it->next) {
 950                 if (cmplen == 0) {
 951                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 952                 }
 953                 else {
 954                         struct tree_desc tree;
 955                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 956                         add_pbase_object(&tree, name, cmplen, name);
 957                 }
 958         }
 959 }
 960
 961 static void add_preferred_base(unsigned char *sha1)
 962 {
 963         struct pbase_tree *it;
 964         void *data;
 965         unsigned long size;
 966         unsigned char tree_sha1[20];
 967
 968         if (window <= num_preferred_base++)
 969                 return;
 970
 971         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 972         if (!data)
 973                 return;
 974
 975         for (it = pbase_tree; it; it = it->next) {
 976                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 977                         free(data);
 978                         return;
 979                 }
 980         }
 981
 982         it = xcalloc(1, sizeof(*it));
 983         it->next = pbase_tree;
 984         pbase_tree = it;
 985
 986         hashcpy(it->pcache.sha1, tree_sha1);
 987         it->pcache.tree_data = data;
 988         it->pcache.tree_size = size;
 989 }
 990
 991 static void check_object(struct object_entry *entry)
 992 {
 993         if (entry->in_pack) {
 994                 struct packed_git *p = entry->in_pack;
 995                 struct pack_window *w_curs = NULL;
 996                 const unsigned char *base_ref = NULL;
 997                 struct object_entry *base_entry;
 998                 unsigned long used, used_0;
 999                 unsigned int avail;
1000                 off_t ofs;
1001                 unsigned char *buf, c;
1002
1003                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1004
1005                 /*
1006                  * We want in_pack_type even if we do not reuse delta
1007                  * since non-delta representations could still be reused.
1008                  */
1009                 used = unpack_object_header_gently(buf, avail,
1010                                                    &entry->in_pack_type,
1011                                                    &entry->size);
1012
1013                 /*
1014                  * Determine if this is a delta and if so whether we can
1015                  * reuse it or not.  Otherwise let's find out as cheaply as
1016                  * possible what the actual type and size for this object is.
1017                  */
1018                 switch (entry->in_pack_type) {
1019                 default:
1020                         /* Not a delta hence we've already got all we need. */
1021                         entry->type = entry->in_pack_type;
1022                         entry->in_pack_header_size = used;
1023                         unuse_pack(&w_curs);
1024                         return;
1025                 case OBJ_REF_DELTA:
1026                         if (reuse_delta && !entry->preferred_base)
1027                                 base_ref = use_pack(p, &w_curs,
1028                                                 entry->in_pack_offset + used, NULL);
1029                         entry->in_pack_header_size = used + 20;
1030                         break;
1031                 case OBJ_OFS_DELTA:
1032                         buf = use_pack(p, &w_curs,
1033                                        entry->in_pack_offset + used, NULL);
1034                         used_0 = 0;
1035                         c = buf[used_0++];
1036                         ofs = c & 127;
1037                         while (c & 128) {
1038                                 ofs += 1;
1039                                 if (!ofs || MSB(ofs, 7))
1040                                         die("delta base offset overflow in pack for %s",
1041                                             sha1_to_hex(entry->idx.sha1));
1042                                 c = buf[used_0++];
1043                                 ofs = (ofs << 7) + (c & 127);
1044                         }
1045                         if (ofs >= entry->in_pack_offset)
1046                                 die("delta base offset out of bound for %s",
1047                                     sha1_to_hex(entry->idx.sha1));
1048                         ofs = entry->in_pack_offset - ofs;
1049                         if (reuse_delta && !entry->preferred_base) {
1050                                 struct revindex_entry *revidx;
1051                                 revidx = find_pack_revindex(p, ofs);
1052                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1053                         }
1054                         entry->in_pack_header_size = used + used_0;
1055                         break;
1056                 }
1057
1058                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1059                         /*
1060                          * If base_ref was set above that means we wish to
1061                          * reuse delta data, and we even found that base
1062                          * in the list of objects we want to pack. Goodie!
1063                          *
1064                          * Depth value does not matter - find_deltas() will
1065                          * never consider reused delta as the base object to
1066                          * deltify other objects against, in order to avoid
1067                          * circular deltas.
1068                          */
1069                         entry->type = entry->in_pack_type;
1070                         entry->delta = base_entry;
1071                         entry->delta_sibling = base_entry->delta_child;
1072                         base_entry->delta_child = entry;
1073                         unuse_pack(&w_curs);
1074                         return;
1075                 }
1076
1077                 if (entry->type) {
1078                         /*
1079                          * This must be a delta and we already know what the
1080                          * final object type is.  Let's extract the actual
1081                          * object size from the delta header.
1082                          */
1083                         entry->size = get_size_from_delta(p, &w_curs,
1084                                         entry->in_pack_offset + entry->in_pack_header_size);
1085                         unuse_pack(&w_curs);
1086                         return;
1087                 }
1088
1089                 /*
1090                  * No choice but to fall back to the recursive delta walk
1091                  * with sha1_object_info() to find about the object type
1092                  * at this point...
1093                  */
1094                 unuse_pack(&w_curs);
1095         }
1096
1097         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1098         if (entry->type < 0)
1099                 die("unable to get type of object %s",
1100                     sha1_to_hex(entry->idx.sha1));
1101 }
1102
1103 static int pack_offset_sort(const void *_a, const void *_b)
1104 {
1105         const struct object_entry *a = *(struct object_entry **)_a;
1106         const struct object_entry *b = *(struct object_entry **)_b;
1107
1108         /* avoid filesystem trashing with loose objects */
1109         if (!a->in_pack && !b->in_pack)
1110                 return hashcmp(a->idx.sha1, b->idx.sha1);
1111
1112         if (a->in_pack < b->in_pack)
1113                 return -1;
1114         if (a->in_pack > b->in_pack)
1115                 return 1;
1116         return a->in_pack_offset < b->in_pack_offset ? -1 :
1117                         (a->in_pack_offset > b->in_pack_offset);
1118 }
1119
1120 static void get_object_details(void)
1121 {
1122         uint32_t i;
1123         struct object_entry **sorted_by_offset;
1124
1125         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1126         for (i = 0; i < nr_objects; i++)
1127                 sorted_by_offset[i] = objects + i;
1128         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1129
1130         for (i = 0; i < nr_objects; i++)
1131                 check_object(sorted_by_offset[i]);
1132
1133         free(sorted_by_offset);
1134 }
1135
1136 /*
1137  * We search for deltas in a list sorted by type, by filename hash, and then
1138  * by size, so that we see progressively smaller and smaller files.
1139  * That's because we prefer deltas to be from the bigger file
1140  * to the smaller -- deletes are potentially cheaper, but perhaps
1141  * more importantly, the bigger file is likely the more recent
1142  * one.  The deepest deltas are therefore the oldest objects which are
1143  * less susceptible to be accessed often.
1144  */
1145 static int type_size_sort(const void *_a, const void *_b)
1146 {
1147         const struct object_entry *a = *(struct object_entry **)_a;
1148         const struct object_entry *b = *(struct object_entry **)_b;
1149
1150         if (a->type > b->type)
1151                 return -1;
1152         if (a->type < b->type)
1153                 return 1;
1154         if (a->hash > b->hash)
1155                 return -1;
1156         if (a->hash < b->hash)
1157                 return 1;
1158         if (a->preferred_base > b->preferred_base)
1159                 return -1;
1160         if (a->preferred_base < b->preferred_base)
1161                 return 1;
1162         if (a->size > b->size)
1163                 return -1;
1164         if (a->size < b->size)
1165                 return 1;
1166         return a < b ? -1 : (a > b);  /* newest first */
1167 }
1168
1169 struct unpacked {
1170         struct object_entry *entry;
1171         void *data;
1172         struct delta_index *index;
1173         unsigned depth;
1174 };
1175
1176 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1177                            unsigned long delta_size)
1178 {
1179         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1180                 return 0;
1181
1182         if (delta_size < cache_max_small_delta_size)
1183                 return 1;
1184
1185         /* cache delta, if objects are large enough compared to delta size */
1186         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1187                 return 1;
1188
1189         return 0;
1190 }
1191
1192 #ifdef THREADED_DELTA_SEARCH
1193
1194 static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1195 #define read_lock()             pthread_mutex_lock(&read_mutex)
1196 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1197
1198 static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1199 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1200 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1201
1202 static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1203 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1204 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1205
1206 #else
1207
1208 #define read_lock()             (void)0
1209 #define read_unlock()           (void)0
1210 #define cache_lock()            (void)0
1211 #define cache_unlock()          (void)0
1212 #define progress_lock()         (void)0
1213 #define progress_unlock()       (void)0
1214
1215 #endif
1216
1217 static int try_delta(struct unpacked *trg, struct unpacked *src,
1218                      unsigned max_depth, unsigned long *mem_usage)
1219 {
1220         struct object_entry *trg_entry = trg->entry;
1221         struct object_entry *src_entry = src->entry;
1222         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1223         unsigned ref_depth;
1224         enum object_type type;
1225         void *delta_buf;
1226
1227         /* Don't bother doing diffs between different types */
1228         if (trg_entry->type != src_entry->type)
1229                 return -1;
1230
1231         /*
1232          * We do not bother to try a delta that we discarded
1233          * on an earlier try, but only when reusing delta data.
1234          */
1235         if (reuse_delta && trg_entry->in_pack &&
1236             trg_entry->in_pack == src_entry->in_pack &&
1237             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1238             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1239                 return 0;
1240
1241         /* Let's not bust the allowed depth. */
1242         if (src->depth >= max_depth)
1243                 return 0;
1244
1245         /* Now some size filtering heuristics. */
1246         trg_size = trg_entry->size;
1247         if (!trg_entry->delta) {
1248                 max_size = trg_size/2 - 20;
1249                 ref_depth = 1;
1250         } else {
1251                 max_size = trg_entry->delta_size;
1252                 ref_depth = trg->depth;
1253         }
1254         max_size = max_size * (max_depth - src->depth) /
1255                                                 (max_depth - ref_depth + 1);
1256         if (max_size == 0)
1257                 return 0;
1258         src_size = src_entry->size;
1259         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1260         if (sizediff >= max_size)
1261                 return 0;
1262         if (trg_size < src_size / 32)
1263                 return 0;
1264
1265         /* Load data if not already done */
1266         if (!trg->data) {
1267                 read_lock();
1268                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1269                 read_unlock();
1270                 if (!trg->data)
1271                         die("object %s cannot be read",
1272                             sha1_to_hex(trg_entry->idx.sha1));
1273                 if (sz != trg_size)
1274                         die("object %s inconsistent object length (%lu vs %lu)",
1275                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1276                 *mem_usage += sz;
1277         }
1278         if (!src->data) {
1279                 read_lock();
1280                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1281                 read_unlock();
1282                 if (!src->data)
1283                         die("object %s cannot be read",
1284                             sha1_to_hex(src_entry->idx.sha1));
1285                 if (sz != src_size)
1286                         die("object %s inconsistent object length (%lu vs %lu)",
1287                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1288                 *mem_usage += sz;
1289         }
1290         if (!src->index) {
1291                 src->index = create_delta_index(src->data, src_size);
1292                 if (!src->index) {
1293                         static int warned = 0;
1294                         if (!warned++)
1295                                 warning("suboptimal pack - out of memory");
1296                         return 0;
1297                 }
1298                 *mem_usage += sizeof_delta_index(src->index);
1299         }
1300
1301         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1302         if (!delta_buf)
1303                 return 0;
1304
1305         if (trg_entry->delta) {
1306                 /* Prefer only shallower same-sized deltas. */
1307                 if (delta_size == trg_entry->delta_size &&
1308                     src->depth + 1 >= trg->depth) {
1309                         free(delta_buf);
1310                         return 0;
1311                 }
1312         }
1313
1314         /*
1315          * Handle memory allocation outside of the cache
1316          * accounting lock.  Compiler will optimize the strangeness
1317          * away when THREADED_DELTA_SEARCH is not defined.
1318          */
1319         free(trg_entry->delta_data);
1320         cache_lock();
1321         if (trg_entry->delta_data) {
1322                 delta_cache_size -= trg_entry->delta_size;
1323                 trg_entry->delta_data = NULL;
1324         }
1325         if (delta_cacheable(src_size, trg_size, delta_size)) {
1326                 delta_cache_size += delta_size;
1327                 cache_unlock();
1328                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1329         } else {
1330                 cache_unlock();
1331                 free(delta_buf);
1332         }
1333
1334         trg_entry->delta = src_entry;
1335         trg_entry->delta_size = delta_size;
1336         trg->depth = src->depth + 1;
1337
1338         return 1;
1339 }
1340
1341 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1342 {
1343         struct object_entry *child = me->delta_child;
1344         unsigned int m = n;
1345         while (child) {
1346                 unsigned int c = check_delta_limit(child, n + 1);
1347                 if (m < c)
1348                         m = c;
1349                 child = child->delta_sibling;
1350         }
1351         return m;
1352 }
1353
1354 static unsigned long free_unpacked(struct unpacked *n)
1355 {
1356         unsigned long freed_mem = sizeof_delta_index(n->index);
1357         free_delta_index(n->index);
1358         n->index = NULL;
1359         if (n->data) {
1360                 freed_mem += n->entry->size;
1361                 free(n->data);
1362                 n->data = NULL;
1363         }
1364         n->entry = NULL;
1365         n->depth = 0;
1366         return freed_mem;
1367 }
1368
1369 static void find_deltas(struct object_entry **list, unsigned *list_size,
1370                         int window, int depth, unsigned *processed)
1371 {
1372         uint32_t i, idx = 0, count = 0;
1373         unsigned int array_size = window * sizeof(struct unpacked);
1374         struct unpacked *array;
1375         unsigned long mem_usage = 0;
1376
1377         array = xmalloc(array_size);
1378         memset(array, 0, array_size);
1379
1380         for (;;) {
1381                 struct object_entry *entry = *list++;
1382                 struct unpacked *n = array + idx;
1383                 int j, max_depth, best_base = -1;
1384
1385                 progress_lock();
1386                 if (!*list_size) {
1387                         progress_unlock();
1388                         break;
1389                 }
1390                 (*list_size)--;
1391                 if (!entry->preferred_base) {
1392                         (*processed)++;
1393                         display_progress(progress_state, *processed);
1394                 }
1395                 progress_unlock();
1396
1397                 mem_usage -= free_unpacked(n);
1398                 n->entry = entry;
1399
1400                 while (window_memory_limit &&
1401                        mem_usage > window_memory_limit &&
1402                        count > 1) {
1403                         uint32_t tail = (idx + window - count) % window;
1404                         mem_usage -= free_unpacked(array + tail);
1405                         count--;
1406                 }
1407
1408                 /* We do not compute delta to *create* objects we are not
1409                  * going to pack.
1410                  */
1411                 if (entry->preferred_base)
1412                         goto next;
1413
1414                 /*
1415                  * If the current object is at pack edge, take the depth the
1416                  * objects that depend on the current object into account
1417                  * otherwise they would become too deep.
1418                  */
1419                 max_depth = depth;
1420                 if (entry->delta_child) {
1421                         max_depth -= check_delta_limit(entry, 0);
1422                         if (max_depth <= 0)
1423                                 goto next;
1424                 }
1425
1426                 j = window;
1427                 while (--j > 0) {
1428                         int ret;
1429                         uint32_t other_idx = idx + j;
1430                         struct unpacked *m;
1431                         if (other_idx >= window)
1432                                 other_idx -= window;
1433                         m = array + other_idx;
1434                         if (!m->entry)
1435                                 break;
1436                         ret = try_delta(n, m, max_depth, &mem_usage);
1437                         if (ret < 0)
1438                                 break;
1439                         else if (ret > 0)
1440                                 best_base = other_idx;
1441                 }
1442
1443                 /*
1444                  * If we decided to cache the delta data, then it is best
1445                  * to compress it right away.  First because we have to do
1446                  * it anyway, and doing it here while we're threaded will
1447                  * save a lot of time in the non threaded write phase,
1448                  * as well as allow for caching more deltas within
1449                  * the same cache size limit.
1450                  * ...
1451                  * But only if not writing to stdout, since in that case
1452                  * the network is most likely throttling writes anyway,
1453                  * and therefore it is best to go to the write phase ASAP
1454                  * instead, as we can afford spending more time compressing
1455                  * between writes at that moment.
1456                  */
1457                 if (entry->delta_data && !pack_to_stdout) {
1458                         entry->z_delta_size = do_compress(&entry->delta_data,
1459                                                           entry->delta_size);
1460                         cache_lock();
1461                         delta_cache_size -= entry->delta_size;
1462                         delta_cache_size += entry->z_delta_size;
1463                         cache_unlock();
1464                 }
1465
1466                 /* if we made n a delta, and if n is already at max
1467                  * depth, leaving it in the window is pointless.  we
1468                  * should evict it first.
1469                  */
1470                 if (entry->delta && max_depth <= n->depth)
1471                         continue;
1472
1473                 /*
1474                  * Move the best delta base up in the window, after the
1475                  * currently deltified object, to keep it longer.  It will
1476                  * be the first base object to be attempted next.
1477                  */
1478                 if (entry->delta) {
1479                         struct unpacked swap = array[best_base];
1480                         int dist = (window + idx - best_base) % window;
1481                         int dst = best_base;
1482                         while (dist--) {
1483                                 int src = (dst + 1) % window;
1484                                 array[dst] = array[src];
1485                                 dst = src;
1486                         }
1487                         array[dst] = swap;
1488                 }
1489
1490                 next:
1491                 idx++;
1492                 if (count + 1 < window)
1493                         count++;
1494                 if (idx >= window)
1495                         idx = 0;
1496         }
1497
1498         for (i = 0; i < window; ++i) {
1499                 free_delta_index(array[i].index);
1500                 free(array[i].data);
1501         }
1502         free(array);
1503 }
1504
1505 #ifdef THREADED_DELTA_SEARCH
1506
1507 /*
1508  * The main thread waits on the condition that (at least) one of the workers
1509  * has stopped working (which is indicated in the .working member of
1510  * struct thread_params).
1511  * When a work thread has completed its work, it sets .working to 0 and
1512  * signals the main thread and waits on the condition that .data_ready
1513  * becomes 1.
1514  */
1515
1516 struct thread_params {
1517         pthread_t thread;
1518         struct object_entry **list;
1519         unsigned list_size;
1520         unsigned remaining;
1521         int window;
1522         int depth;
1523         int working;
1524         int data_ready;
1525         pthread_mutex_t mutex;
1526         pthread_cond_t cond;
1527         unsigned *processed;
1528 };
1529
1530 static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
1531
1532 static void *threaded_find_deltas(void *arg)
1533 {
1534         struct thread_params *me = arg;
1535
1536         while (me->remaining) {
1537                 find_deltas(me->list, &me->remaining,
1538                             me->window, me->depth, me->processed);
1539
1540                 progress_lock();
1541                 me->working = 0;
1542                 pthread_cond_signal(&progress_cond);
1543                 progress_unlock();
1544
1545                 /*
1546                  * We must not set ->data_ready before we wait on the
1547                  * condition because the main thread may have set it to 1
1548                  * before we get here. In order to be sure that new
1549                  * work is available if we see 1 in ->data_ready, it
1550                  * was initialized to 0 before this thread was spawned
1551                  * and we reset it to 0 right away.
1552                  */
1553                 pthread_mutex_lock(&me->mutex);
1554                 while (!me->data_ready)
1555                         pthread_cond_wait(&me->cond, &me->mutex);
1556                 me->data_ready = 0;
1557                 pthread_mutex_unlock(&me->mutex);
1558         }
1559         /* leave ->working 1 so that this doesn't get more work assigned */
1560         return NULL;
1561 }
1562
1563 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1564                            int window, int depth, unsigned *processed)
1565 {
1566         struct thread_params p[delta_search_threads];
1567         int i, ret, active_threads = 0;
1568
1569         if (delta_search_threads <= 1) {
1570                 find_deltas(list, &list_size, window, depth, processed);
1571                 return;
1572         }
1573
1574         /* Partition the work amongst work threads. */
1575         for (i = 0; i < delta_search_threads; i++) {
1576                 unsigned sub_size = list_size / (delta_search_threads - i);
1577
1578                 p[i].window = window;
1579                 p[i].depth = depth;
1580                 p[i].processed = processed;
1581                 p[i].working = 1;
1582                 p[i].data_ready = 0;
1583
1584                 /* try to split chunks on "path" boundaries */
1585                 while (sub_size && sub_size < list_size &&
1586                        list[sub_size]->hash &&
1587                        list[sub_size]->hash == list[sub_size-1]->hash)
1588                         sub_size++;
1589
1590                 p[i].list = list;
1591                 p[i].list_size = sub_size;
1592                 p[i].remaining = sub_size;
1593
1594                 list += sub_size;
1595                 list_size -= sub_size;
1596         }
1597
1598         /* Start work threads. */
1599         for (i = 0; i < delta_search_threads; i++) {
1600                 if (!p[i].list_size)
1601                         continue;
1602                 pthread_mutex_init(&p[i].mutex, NULL);
1603                 pthread_cond_init(&p[i].cond, NULL);
1604                 ret = pthread_create(&p[i].thread, NULL,
1605                                      threaded_find_deltas, &p[i]);
1606                 if (ret)
1607                         die("unable to create thread: %s", strerror(ret));
1608                 active_threads++;
1609         }
1610
1611         /*
1612          * Now let's wait for work completion.  Each time a thread is done
1613          * with its work, we steal half of the remaining work from the
1614          * thread with the largest number of unprocessed objects and give
1615          * it to that newly idle thread.  This ensure good load balancing
1616          * until the remaining object list segments are simply too short
1617          * to be worth splitting anymore.
1618          */
1619         while (active_threads) {
1620                 struct thread_params *target = NULL;
1621                 struct thread_params *victim = NULL;
1622                 unsigned sub_size = 0;
1623
1624                 progress_lock();
1625                 for (;;) {
1626                         for (i = 0; !target && i < delta_search_threads; i++)
1627                                 if (!p[i].working)
1628                                         target = &p[i];
1629                         if (target)
1630                                 break;
1631                         pthread_cond_wait(&progress_cond, &progress_mutex);
1632                 }
1633
1634                 for (i = 0; i < delta_search_threads; i++)
1635                         if (p[i].remaining > 2*window &&
1636                             (!victim || victim->remaining < p[i].remaining))
1637                                 victim = &p[i];
1638                 if (victim) {
1639                         sub_size = victim->remaining / 2;
1640                         list = victim->list + victim->list_size - sub_size;
1641                         while (sub_size && list[0]->hash &&
1642                                list[0]->hash == list[-1]->hash) {
1643                                 list++;
1644                                 sub_size--;
1645                         }
1646                         if (!sub_size) {
1647                                 /*
1648                                  * It is possible for some "paths" to have
1649                                  * so many objects that no hash boundary
1650                                  * might be found.  Let's just steal the
1651                                  * exact half in that case.
1652                                  */
1653                                 sub_size = victim->remaining / 2;
1654                                 list -= sub_size;
1655                         }
1656                         target->list = list;
1657                         victim->list_size -= sub_size;
1658                         victim->remaining -= sub_size;
1659                 }
1660                 target->list_size = sub_size;
1661                 target->remaining = sub_size;
1662                 target->working = 1;
1663                 progress_unlock();
1664
1665                 pthread_mutex_lock(&target->mutex);
1666                 target->data_ready = 1;
1667                 pthread_cond_signal(&target->cond);
1668                 pthread_mutex_unlock(&target->mutex);
1669
1670                 if (!sub_size) {
1671                         pthread_join(target->thread, NULL);
1672                         pthread_cond_destroy(&target->cond);
1673                         pthread_mutex_destroy(&target->mutex);
1674                         active_threads--;
1675                 }
1676         }
1677 }
1678
1679 #else
1680 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1681 #endif
1682
1683 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1684 {
1685         unsigned char peeled[20];
1686
1687         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1688             !peel_ref(path, peeled)        && /* peelable? */
1689             !is_null_sha1(peeled)          && /* annotated tag? */
1690             locate_object_entry(peeled))      /* object packed? */
1691                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1692         return 0;
1693 }
1694
1695 static void prepare_pack(int window, int depth)
1696 {
1697         struct object_entry **delta_list;
1698         uint32_t i, nr_deltas;
1699         unsigned n;
1700
1701         get_object_details();
1702
1703         if (!nr_objects || !window || !depth)
1704                 return;
1705
1706         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1707         nr_deltas = n = 0;
1708
1709         for (i = 0; i < nr_objects; i++) {
1710                 struct object_entry *entry = objects + i;
1711
1712                 if (entry->delta)
1713                         /* This happens if we decided to reuse existing
1714                          * delta from a pack.  "reuse_delta &&" is implied.
1715                          */
1716                         continue;
1717
1718                 if (entry->size < 50)
1719                         continue;
1720
1721                 if (entry->no_try_delta)
1722                         continue;
1723
1724                 if (!entry->preferred_base)
1725                         nr_deltas++;
1726
1727                 delta_list[n++] = entry;
1728         }
1729
1730         if (nr_deltas && n > 1) {
1731                 unsigned nr_done = 0;
1732                 if (progress)
1733                         progress_state = start_progress("Compressing objects",
1734                                                         nr_deltas);
1735                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1736                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1737                 stop_progress(&progress_state);
1738                 if (nr_done != nr_deltas)
1739                         die("inconsistency with delta count");
1740         }
1741         free(delta_list);
1742 }
1743
1744 static int git_pack_config(const char *k, const char *v, void *cb)
1745 {
1746         if(!strcmp(k, "pack.window")) {
1747                 window = git_config_int(k, v);
1748                 return 0;
1749         }
1750         if (!strcmp(k, "pack.windowmemory")) {
1751                 window_memory_limit = git_config_ulong(k, v);
1752                 return 0;
1753         }
1754         if (!strcmp(k, "pack.depth")) {
1755                 depth = git_config_int(k, v);
1756                 return 0;
1757         }
1758         if (!strcmp(k, "pack.compression")) {
1759                 int level = git_config_int(k, v);
1760                 if (level == -1)
1761                         level = Z_DEFAULT_COMPRESSION;
1762                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1763                         die("bad pack compression level %d", level);
1764                 pack_compression_level = level;
1765                 pack_compression_seen = 1;
1766                 return 0;
1767         }
1768         if (!strcmp(k, "pack.deltacachesize")) {
1769                 max_delta_cache_size = git_config_int(k, v);
1770                 return 0;
1771         }
1772         if (!strcmp(k, "pack.deltacachelimit")) {
1773                 cache_max_small_delta_size = git_config_int(k, v);
1774                 return 0;
1775         }
1776         if (!strcmp(k, "pack.threads")) {
1777                 delta_search_threads = git_config_int(k, v);
1778                 if (delta_search_threads < 0)
1779                         die("invalid number of threads specified (%d)",
1780                             delta_search_threads);
1781 #ifndef THREADED_DELTA_SEARCH
1782                 if (delta_search_threads != 1)
1783                         warning("no threads support, ignoring %s", k);
1784 #endif
1785                 return 0;
1786         }
1787         if (!strcmp(k, "pack.indexversion")) {
1788                 pack_idx_default_version = git_config_int(k, v);
1789                 if (pack_idx_default_version > 2)
1790                         die("bad pack.indexversion=%"PRIu32,
1791                                 pack_idx_default_version);
1792                 return 0;
1793         }
1794         if (!strcmp(k, "pack.packsizelimit")) {
1795                 pack_size_limit_cfg = git_config_ulong(k, v);
1796                 return 0;
1797         }
1798         return git_default_config(k, v, cb);
1799 }
1800
1801 static void read_object_list_from_stdin(void)
1802 {
1803         char line[40 + 1 + PATH_MAX + 2];
1804         unsigned char sha1[20];
1805
1806         for (;;) {
1807                 if (!fgets(line, sizeof(line), stdin)) {
1808                         if (feof(stdin))
1809                                 break;
1810                         if (!ferror(stdin))
1811                                 die("fgets returned NULL, not EOF, not error!");
1812                         if (errno != EINTR)
1813                                 die("fgets: %s", strerror(errno));
1814                         clearerr(stdin);
1815                         continue;
1816                 }
1817                 if (line[0] == '-') {
1818                         if (get_sha1_hex(line+1, sha1))
1819                                 die("expected edge sha1, got garbage:\n %s",
1820                                     line);
1821                         add_preferred_base(sha1);
1822                         continue;
1823                 }
1824                 if (get_sha1_hex(line, sha1))
1825                         die("expected sha1, got garbage:\n %s", line);
1826
1827                 add_preferred_base_object(line+41);
1828                 add_object_entry(sha1, 0, line+41, 0);
1829         }
1830 }
1831
1832 #define OBJECT_ADDED (1u<<20)
1833
1834 static void show_commit(struct commit *commit)
1835 {
1836         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1837         commit->object.flags |= OBJECT_ADDED;
1838 }
1839
1840 static void show_object(struct object_array_entry *p)
1841 {
1842         add_preferred_base_object(p->name);
1843         add_object_entry(p->item->sha1, p->item->type, p->name, 0);
1844         p->item->flags |= OBJECT_ADDED;
1845 }
1846
1847 static void show_edge(struct commit *commit)
1848 {
1849         add_preferred_base(commit->object.sha1);
1850 }
1851
1852 struct in_pack_object {
1853         off_t offset;
1854         struct object *object;
1855 };
1856
1857 struct in_pack {
1858         int alloc;
1859         int nr;
1860         struct in_pack_object *array;
1861 };
1862
1863 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1864 {
1865         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1866         in_pack->array[in_pack->nr].object = object;
1867         in_pack->nr++;
1868 }
1869
1870 /*
1871  * Compare the objects in the offset order, in order to emulate the
1872  * "git-rev-list --objects" output that produced the pack originally.
1873  */
1874 static int ofscmp(const void *a_, const void *b_)
1875 {
1876         struct in_pack_object *a = (struct in_pack_object *)a_;
1877         struct in_pack_object *b = (struct in_pack_object *)b_;
1878
1879         if (a->offset < b->offset)
1880                 return -1;
1881         else if (a->offset > b->offset)
1882                 return 1;
1883         else
1884                 return hashcmp(a->object->sha1, b->object->sha1);
1885 }
1886
1887 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1888 {
1889         struct packed_git *p;
1890         struct in_pack in_pack;
1891         uint32_t i;
1892
1893         memset(&in_pack, 0, sizeof(in_pack));
1894
1895         for (p = packed_git; p; p = p->next) {
1896                 const unsigned char *sha1;
1897                 struct object *o;
1898
1899                 for (i = 0; i < revs->num_ignore_packed; i++) {
1900                         if (matches_pack_name(p, revs->ignore_packed[i]))
1901                                 break;
1902                 }
1903                 if (revs->num_ignore_packed <= i)
1904                         continue;
1905                 if (open_pack_index(p))
1906                         die("cannot open pack index");
1907
1908                 ALLOC_GROW(in_pack.array,
1909                            in_pack.nr + p->num_objects,
1910                            in_pack.alloc);
1911
1912                 for (i = 0; i < p->num_objects; i++) {
1913                         sha1 = nth_packed_object_sha1(p, i);
1914                         o = lookup_unknown_object(sha1);
1915                         if (!(o->flags & OBJECT_ADDED))
1916                                 mark_in_pack_object(o, p, &in_pack);
1917                         o->flags |= OBJECT_ADDED;
1918                 }
1919         }
1920
1921         if (in_pack.nr) {
1922                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
1923                       ofscmp);
1924                 for (i = 0; i < in_pack.nr; i++) {
1925                         struct object *o = in_pack.array[i].object;
1926                         add_object_entry(o->sha1, o->type, "", 0);
1927                 }
1928         }
1929         free(in_pack.array);
1930 }
1931
1932 static void loosen_unused_packed_objects(struct rev_info *revs)
1933 {
1934         struct packed_git *p;
1935         uint32_t i;
1936         const unsigned char *sha1;
1937
1938         for (p = packed_git; p; p = p->next) {
1939                 for (i = 0; i < revs->num_ignore_packed; i++) {
1940                         if (matches_pack_name(p, revs->ignore_packed[i]))
1941                                 break;
1942                 }
1943                 if (revs->num_ignore_packed <= i)
1944                         continue;
1945
1946                 if (open_pack_index(p))
1947                         die("cannot open pack index");
1948
1949                 for (i = 0; i < p->num_objects; i++) {
1950                         sha1 = nth_packed_object_sha1(p, i);
1951                         if (!locate_object_entry(sha1))
1952                                 if (force_object_loose(sha1, p->mtime))
1953                                         die("unable to force loose object");
1954                 }
1955         }
1956 }
1957
1958 static void get_object_list(int ac, const char **av)
1959 {
1960         struct rev_info revs;
1961         char line[1000];
1962         int flags = 0;
1963
1964         init_revisions(&revs, NULL);
1965         save_commit_buffer = 0;
1966         setup_revisions(ac, av, &revs, NULL);
1967
1968         while (fgets(line, sizeof(line), stdin) != NULL) {
1969                 int len = strlen(line);
1970                 if (len && line[len - 1] == '\n')
1971                         line[--len] = 0;
1972                 if (!len)
1973                         break;
1974                 if (*line == '-') {
1975                         if (!strcmp(line, "--not")) {
1976                                 flags ^= UNINTERESTING;
1977                                 continue;
1978                         }
1979                         die("not a rev '%s'", line);
1980                 }
1981                 if (handle_revision_arg(line, &revs, flags, 1))
1982                         die("bad revision '%s'", line);
1983         }
1984
1985         if (prepare_revision_walk(&revs))
1986                 die("revision walk setup failed");
1987         mark_edges_uninteresting(revs.commits, &revs, show_edge);
1988         traverse_commit_list(&revs, show_commit, show_object);
1989
1990         if (keep_unreachable)
1991                 add_objects_in_unpacked_packs(&revs);
1992         if (unpack_unreachable)
1993                 loosen_unused_packed_objects(&revs);
1994 }
1995
1996 static int adjust_perm(const char *path, mode_t mode)
1997 {
1998         if (chmod(path, mode))
1999                 return -1;
2000         return adjust_shared_perm(path);
2001 }
2002
2003 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2004 {
2005         int use_internal_rev_list = 0;
2006         int thin = 0;
2007         uint32_t i;
2008         const char **rp_av;
2009         int rp_ac_alloc = 64;
2010         int rp_ac;
2011
2012         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2013
2014         rp_av[0] = "pack-objects";
2015         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2016         rp_ac = 2;
2017
2018         git_config(git_pack_config, NULL);
2019         if (!pack_compression_seen && core_compression_seen)
2020                 pack_compression_level = core_compression_level;
2021
2022         progress = isatty(2);
2023         for (i = 1; i < argc; i++) {
2024                 const char *arg = argv[i];
2025
2026                 if (*arg != '-')
2027                         break;
2028
2029                 if (!strcmp("--non-empty", arg)) {
2030                         non_empty = 1;
2031                         continue;
2032                 }
2033                 if (!strcmp("--local", arg)) {
2034                         local = 1;
2035                         continue;
2036                 }
2037                 if (!strcmp("--incremental", arg)) {
2038                         incremental = 1;
2039                         continue;
2040                 }
2041                 if (!prefixcmp(arg, "--compression=")) {
2042                         char *end;
2043                         int level = strtoul(arg+14, &end, 0);
2044                         if (!arg[14] || *end)
2045                                 usage(pack_usage);
2046                         if (level == -1)
2047                                 level = Z_DEFAULT_COMPRESSION;
2048                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2049                                 die("bad pack compression level %d", level);
2050                         pack_compression_level = level;
2051                         continue;
2052                 }
2053                 if (!prefixcmp(arg, "--max-pack-size=")) {
2054                         char *end;
2055                         pack_size_limit_cfg = 0;
2056                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2057                         if (!arg[16] || *end)
2058                                 usage(pack_usage);
2059                         continue;
2060                 }
2061                 if (!prefixcmp(arg, "--window=")) {
2062                         char *end;
2063                         window = strtoul(arg+9, &end, 0);
2064                         if (!arg[9] || *end)
2065                                 usage(pack_usage);
2066                         continue;
2067                 }
2068                 if (!prefixcmp(arg, "--window-memory=")) {
2069                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2070                                 usage(pack_usage);
2071                         continue;
2072                 }
2073                 if (!prefixcmp(arg, "--threads=")) {
2074                         char *end;
2075                         delta_search_threads = strtoul(arg+10, &end, 0);
2076                         if (!arg[10] || *end || delta_search_threads < 0)
2077                                 usage(pack_usage);
2078 #ifndef THREADED_DELTA_SEARCH
2079                         if (delta_search_threads != 1)
2080                                 warning("no threads support, "
2081                                         "ignoring %s", arg);
2082 #endif
2083                         continue;
2084                 }
2085                 if (!prefixcmp(arg, "--depth=")) {
2086                         char *end;
2087                         depth = strtoul(arg+8, &end, 0);
2088                         if (!arg[8] || *end)
2089                                 usage(pack_usage);
2090                         continue;
2091                 }
2092                 if (!strcmp("--progress", arg)) {
2093                         progress = 1;
2094                         continue;
2095                 }
2096                 if (!strcmp("--all-progress", arg)) {
2097                         progress = 2;
2098                         continue;
2099                 }
2100                 if (!strcmp("-q", arg)) {
2101                         progress = 0;
2102                         continue;
2103                 }
2104                 if (!strcmp("--no-reuse-delta", arg)) {
2105                         reuse_delta = 0;
2106                         continue;
2107                 }
2108                 if (!strcmp("--no-reuse-object", arg)) {
2109                         reuse_object = reuse_delta = 0;
2110                         continue;
2111                 }
2112                 if (!strcmp("--delta-base-offset", arg)) {
2113                         allow_ofs_delta = 1;
2114                         continue;
2115                 }
2116                 if (!strcmp("--stdout", arg)) {
2117                         pack_to_stdout = 1;
2118                         continue;
2119                 }
2120                 if (!strcmp("--revs", arg)) {
2121                         use_internal_rev_list = 1;
2122                         continue;
2123                 }
2124                 if (!strcmp("--keep-unreachable", arg)) {
2125                         keep_unreachable = 1;
2126                         continue;
2127                 }
2128                 if (!strcmp("--unpack-unreachable", arg)) {
2129                         unpack_unreachable = 1;
2130                         continue;
2131                 }
2132                 if (!strcmp("--include-tag", arg)) {
2133                         include_tag = 1;
2134                         continue;
2135                 }
2136                 if (!strcmp("--unpacked", arg) ||
2137                     !prefixcmp(arg, "--unpacked=") ||
2138                     !strcmp("--reflog", arg) ||
2139                     !strcmp("--all", arg)) {
2140                         use_internal_rev_list = 1;
2141                         if (rp_ac >= rp_ac_alloc - 1) {
2142                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2143                                 rp_av = xrealloc(rp_av,
2144                                                  rp_ac_alloc * sizeof(*rp_av));
2145                         }
2146                         rp_av[rp_ac++] = arg;
2147                         continue;
2148                 }
2149                 if (!strcmp("--thin", arg)) {
2150                         use_internal_rev_list = 1;
2151                         thin = 1;
2152                         rp_av[1] = "--objects-edge";
2153                         continue;
2154                 }
2155                 if (!prefixcmp(arg, "--index-version=")) {
2156                         char *c;
2157                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2158                         if (pack_idx_default_version > 2)
2159                                 die("bad %s", arg);
2160                         if (*c == ',')
2161                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2162                         if (*c || pack_idx_off32_limit & 0x80000000)
2163                                 die("bad %s", arg);
2164                         continue;
2165                 }
2166                 usage(pack_usage);
2167         }
2168
2169         /* Traditionally "pack-objects [options] base extra" failed;
2170          * we would however want to take refs parameter that would
2171          * have been given to upstream rev-list ourselves, which means
2172          * we somehow want to say what the base name is.  So the
2173          * syntax would be:
2174          *
2175          * pack-objects [options] base <refs...>
2176          *
2177          * in other words, we would treat the first non-option as the
2178          * base_name and send everything else to the internal revision
2179          * walker.
2180          */
2181
2182         if (!pack_to_stdout)
2183                 base_name = argv[i++];
2184
2185         if (pack_to_stdout != !base_name)
2186                 usage(pack_usage);
2187
2188         if (!pack_to_stdout && !pack_size_limit)
2189                 pack_size_limit = pack_size_limit_cfg;
2190
2191         if (pack_to_stdout && pack_size_limit)
2192                 die("--max-pack-size cannot be used to build a pack for transfer.");
2193
2194         if (!pack_to_stdout && thin)
2195                 die("--thin cannot be used to build an indexable pack.");
2196
2197         if (keep_unreachable && unpack_unreachable)
2198                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2199
2200 #ifdef THREADED_DELTA_SEARCH
2201         if (!delta_search_threads)      /* --threads=0 means autodetect */
2202                 delta_search_threads = online_cpus();
2203 #endif
2204
2205         prepare_packed_git();
2206
2207         if (progress)
2208                 progress_state = start_progress("Counting objects", 0);
2209         if (!use_internal_rev_list)
2210                 read_object_list_from_stdin();
2211         else {
2212                 rp_av[rp_ac] = NULL;
2213                 get_object_list(rp_ac, rp_av);
2214         }
2215         if (include_tag && nr_result)
2216                 for_each_ref(add_ref_tag, NULL);
2217         stop_progress(&progress_state);
2218
2219         if (non_empty && !nr_result)
2220                 return 0;
2221         if (nr_result)
2222                 prepare_pack(window, depth);
2223         write_pack_file();
2224         if (progress)
2225                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2226                         " reused %"PRIu32" (delta %"PRIu32")\n",
2227                         written, written_delta, reused, reused_delta);
2228         return 0;
2229 }