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

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "attr.h"
   4 #include "object.h"
   5 #include "blob.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "tree.h"
   9 #include "delta.h"
  10 #include "pack.h"
  11 #include "pack-revindex.h"
  12 #include "csum-file.h"
  13 #include "tree-walk.h"
  14 #include "diff.h"
  15 #include "revision.h"
  16 #include "list-objects.h"
  17 #include "progress.h"
  18 #include "refs.h"
  19
  20 #ifdef THREADED_DELTA_SEARCH
  21 #include "thread-utils.h"
  22 #include <pthread.h>
  23 #endif
  24
  25 static const char pack_usage[] = "\
  26 git pack-objects [{ -q | --progress | --all-progress }] \n\
  27         [--max-pack-size=N] [--local] [--incremental] \n\
  28         [--window=N] [--window-memory=N] [--depth=N] \n\
  29         [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
  30         [--threads=N] [--non-empty] [--revs [--unpacked | --all]*] [--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 ignore_packed_keep;
  75 static int allow_ofs_delta;
  76 static const char *base_name;
  77 static int progress = 1;
  78 static int window = 10;
  79 static uint32_t pack_size_limit, pack_size_limit_cfg;
  80 static int depth = 50;
  81 static int delta_search_threads = 1;
  82 static int pack_to_stdout;
  83 static int num_preferred_base;
  84 static struct progress *progress_state;
  85 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  86 static int pack_compression_seen;
  87
  88 static unsigned long delta_cache_size = 0;
  89 static unsigned long max_delta_cache_size = 0;
  90 static unsigned long cache_max_small_delta_size = 1000;
  91
  92 static unsigned long window_memory_limit = 0;
  93
  94 /*
  95  * The object names in objects array are hashed with this hashtable,
  96  * to help looking up the entry by object name.
  97  * This hashtable is built after all the objects are seen.
  98  */
  99 static int *object_ix;
 100 static int object_ix_hashsz;
 101
 102 /*
 103  * stats
 104  */
 105 static uint32_t written, written_delta;
 106 static uint32_t reused, reused_delta;
 107
 108
 109 static void *get_delta(struct object_entry *entry)
 110 {
 111         unsigned long size, base_size, delta_size;
 112         void *buf, *base_buf, *delta_buf;
 113         enum object_type type;
 114
 115         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 116         if (!buf)
 117                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 118         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
 119         if (!base_buf)
 120                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 121         delta_buf = diff_delta(base_buf, base_size,
 122                                buf, size, &delta_size, 0);
 123         if (!delta_buf || delta_size != entry->delta_size)
 124                 die("delta size changed");
 125         free(buf);
 126         free(base_buf);
 127         return delta_buf;
 128 }
 129
 130 static unsigned long do_compress(void **pptr, unsigned long size)
 131 {
 132         z_stream stream;
 133         void *in, *out;
 134         unsigned long maxsize;
 135
 136         memset(&stream, 0, sizeof(stream));
 137         deflateInit(&stream, pack_compression_level);
 138         maxsize = deflateBound(&stream, size);
 139
 140         in = *pptr;
 141         out = xmalloc(maxsize);
 142         *pptr = out;
 143
 144         stream.next_in = in;
 145         stream.avail_in = size;
 146         stream.next_out = out;
 147         stream.avail_out = maxsize;
 148         while (deflate(&stream, Z_FINISH) == Z_OK)
 149                 ; /* nothing */
 150         deflateEnd(&stream);
 151
 152         free(in);
 153         return stream.total_out;
 154 }
 155
 156 /*
 157  * The per-object header is a pretty dense thing, which is
 158  *  - first byte: low four bits are "size", then three bits of "type",
 159  *    and the high bit is "size continues".
 160  *  - each byte afterwards: low seven bits are size continuation,
 161  *    with the high bit being "size continues"
 162  */
 163 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 164 {
 165         int n = 1;
 166         unsigned char c;
 167
 168         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 169                 die("bad type %d", type);
 170
 171         c = (type << 4) | (size & 15);
 172         size >>= 4;
 173         while (size) {
 174                 *hdr++ = c | 0x80;
 175                 c = size & 0x7f;
 176                 size >>= 7;
 177                 n++;
 178         }
 179         *hdr = c;
 180         return n;
 181 }
 182
 183 /*
 184  * we are going to reuse the existing object data as is.  make
 185  * sure it is not corrupt.
 186  */
 187 static int check_pack_inflate(struct packed_git *p,
 188                 struct pack_window **w_curs,
 189                 off_t offset,
 190                 off_t len,
 191                 unsigned long expect)
 192 {
 193         z_stream stream;
 194         unsigned char fakebuf[4096], *in;
 195         int st;
 196
 197         memset(&stream, 0, sizeof(stream));
 198         inflateInit(&stream);
 199         do {
 200                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 201                 stream.next_in = in;
 202                 stream.next_out = fakebuf;
 203                 stream.avail_out = sizeof(fakebuf);
 204                 st = inflate(&stream, Z_FINISH);
 205                 offset += stream.next_in - in;
 206         } while (st == Z_OK || st == Z_BUF_ERROR);
 207         inflateEnd(&stream);
 208         return (st == Z_STREAM_END &&
 209                 stream.total_out == expect &&
 210                 stream.total_in == len) ? 0 : -1;
 211 }
 212
 213 static void copy_pack_data(struct sha1file *f,
 214                 struct packed_git *p,
 215                 struct pack_window **w_curs,
 216                 off_t offset,
 217                 off_t len)
 218 {
 219         unsigned char *in;
 220         unsigned int avail;
 221
 222         while (len) {
 223                 in = use_pack(p, w_curs, offset, &avail);
 224                 if (avail > len)
 225                         avail = (unsigned int)len;
 226                 sha1write(f, in, avail);
 227                 offset += avail;
 228                 len -= avail;
 229         }
 230 }
 231
 232 static unsigned long write_object(struct sha1file *f,
 233                                   struct object_entry *entry,
 234                                   off_t write_offset)
 235 {
 236         unsigned long size, limit, datalen;
 237         void *buf;
 238         unsigned char header[10], dheader[10];
 239         unsigned hdrlen;
 240         enum object_type type;
 241         int usable_delta, to_reuse;
 242
 243         if (!pack_to_stdout)
 244                 crc32_begin(f);
 245
 246         type = entry->type;
 247
 248         /* write limit if limited packsize and not first object */
 249         limit = pack_size_limit && nr_written ?
 250                         pack_size_limit - write_offset : 0;
 251
 252         if (!entry->delta)
 253                 usable_delta = 0;       /* no delta */
 254         else if (!pack_size_limit)
 255                usable_delta = 1;        /* unlimited packfile */
 256         else if (entry->delta->idx.offset == (off_t)-1)
 257                 usable_delta = 0;       /* base was written to another pack */
 258         else if (entry->delta->idx.offset)
 259                 usable_delta = 1;       /* base already exists in this pack */
 260         else
 261                 usable_delta = 0;       /* base could end up in another pack */
 262
 263         if (!reuse_object)
 264                 to_reuse = 0;   /* explicit */
 265         else if (!entry->in_pack)
 266                 to_reuse = 0;   /* can't reuse what we don't have */
 267         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
 268                                 /* check_object() decided it for us ... */
 269                 to_reuse = usable_delta;
 270                                 /* ... but pack split may override that */
 271         else if (type != entry->in_pack_type)
 272                 to_reuse = 0;   /* pack has delta which is unusable */
 273         else if (entry->delta)
 274                 to_reuse = 0;   /* we want to pack afresh */
 275         else
 276                 to_reuse = 1;   /* we have it in-pack undeltified,
 277                                  * and we do not need to deltify it.
 278                                  */
 279
 280         if (!to_reuse) {
 281                 if (!usable_delta) {
 282                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 283                         if (!buf)
 284                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 285                         /*
 286                          * make sure no cached delta data remains from a
 287                          * previous attempt before a pack split occured.
 288                          */
 289                         free(entry->delta_data);
 290                         entry->delta_data = NULL;
 291                         entry->z_delta_size = 0;
 292                 } else if (entry->delta_data) {
 293                         size = entry->delta_size;
 294                         buf = entry->delta_data;
 295                         entry->delta_data = NULL;
 296                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 297                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 298                 } else {
 299                         buf = get_delta(entry);
 300                         size = entry->delta_size;
 301                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 302                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 303                 }
 304
 305                 if (entry->z_delta_size)
 306                         datalen = entry->z_delta_size;
 307                 else
 308                         datalen = do_compress(&buf, size);
 309
 310                 /*
 311                  * The object header is a byte of 'type' followed by zero or
 312                  * more bytes of length.
 313                  */
 314                 hdrlen = encode_header(type, size, header);
 315
 316                 if (type == OBJ_OFS_DELTA) {
 317                         /*
 318                          * Deltas with relative base contain an additional
 319                          * encoding of the relative offset for the delta
 320                          * base from this object's position in the pack.
 321                          */
 322                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 323                         unsigned pos = sizeof(dheader) - 1;
 324                         dheader[pos] = ofs & 127;
 325                         while (ofs >>= 7)
 326                                 dheader[--pos] = 128 | (--ofs & 127);
 327                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 328                                 free(buf);
 329                                 return 0;
 330                         }
 331                         sha1write(f, header, hdrlen);
 332                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 333                         hdrlen += sizeof(dheader) - pos;
 334                 } else if (type == OBJ_REF_DELTA) {
 335                         /*
 336                          * Deltas with a base reference contain
 337                          * an additional 20 bytes for the base sha1.
 338                          */
 339                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 340                                 free(buf);
 341                                 return 0;
 342                         }
 343                         sha1write(f, header, hdrlen);
 344                         sha1write(f, entry->delta->idx.sha1, 20);
 345                         hdrlen += 20;
 346                 } else {
 347                         if (limit && hdrlen + datalen + 20 >= limit) {
 348                                 free(buf);
 349                                 return 0;
 350                         }
 351                         sha1write(f, header, hdrlen);
 352                 }
 353                 sha1write(f, buf, datalen);
 354                 free(buf);
 355         }
 356         else {
 357                 struct packed_git *p = entry->in_pack;
 358                 struct pack_window *w_curs = NULL;
 359                 struct revindex_entry *revidx;
 360                 off_t offset;
 361
 362                 if (entry->delta) {
 363                         type = (allow_ofs_delta && entry->delta->idx.offset) ?
 364                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 365                         reused_delta++;
 366                 }
 367                 hdrlen = encode_header(type, entry->size, header);
 368                 offset = entry->in_pack_offset;
 369                 revidx = find_pack_revindex(p, offset);
 370                 datalen = revidx[1].offset - offset;
 371                 if (!pack_to_stdout && p->index_version > 1 &&
 372                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
 373                         die("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 374                 offset += entry->in_pack_header_size;
 375                 datalen -= entry->in_pack_header_size;
 376                 if (type == OBJ_OFS_DELTA) {
 377                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 378                         unsigned pos = sizeof(dheader) - 1;
 379                         dheader[pos] = ofs & 127;
 380                         while (ofs >>= 7)
 381                                 dheader[--pos] = 128 | (--ofs & 127);
 382                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit)
 383                                 return 0;
 384                         sha1write(f, header, hdrlen);
 385                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 386                         hdrlen += sizeof(dheader) - pos;
 387                 } else if (type == OBJ_REF_DELTA) {
 388                         if (limit && hdrlen + 20 + datalen + 20 >= limit)
 389                                 return 0;
 390                         sha1write(f, header, hdrlen);
 391                         sha1write(f, entry->delta->idx.sha1, 20);
 392                         hdrlen += 20;
 393                 } else {
 394                         if (limit && hdrlen + datalen + 20 >= limit)
 395                                 return 0;
 396                         sha1write(f, header, hdrlen);
 397                 }
 398
 399                 if (!pack_to_stdout && p->index_version == 1 &&
 400                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
 401                         die("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 402                 copy_pack_data(f, p, &w_curs, offset, datalen);
 403                 unuse_pack(&w_curs);
 404                 reused++;
 405         }
 406         if (usable_delta)
 407                 written_delta++;
 408         written++;
 409         if (!pack_to_stdout)
 410                 entry->idx.crc32 = crc32_end(f);
 411         return hdrlen + datalen;
 412 }
 413
 414 static int write_one(struct sha1file *f,
 415                                struct object_entry *e,
 416                                off_t *offset)
 417 {
 418         unsigned long size;
 419
 420         /* offset is non zero if object is written already. */
 421         if (e->idx.offset || e->preferred_base)
 422                 return 1;
 423
 424         /* if we are deltified, write out base object first. */
 425         if (e->delta && !write_one(f, e->delta, offset))
 426                 return 0;
 427
 428         e->idx.offset = *offset;
 429         size = write_object(f, e, *offset);
 430         if (!size) {
 431                 e->idx.offset = 0;
 432                 return 0;
 433         }
 434         written_list[nr_written++] = &e->idx;
 435
 436         /* make sure off_t is sufficiently large not to wrap */
 437         if (*offset > *offset + size)
 438                 die("pack too large for current definition of off_t");
 439         *offset += size;
 440         return 1;
 441 }
 442
 443 /* forward declaration for write_pack_file */
 444 static int adjust_perm(const char *path, mode_t mode);
 445
 446 static void write_pack_file(void)
 447 {
 448         uint32_t i = 0, j;
 449         struct sha1file *f;
 450         off_t offset;
 451         struct pack_header hdr;
 452         uint32_t nr_remaining = nr_result;
 453         time_t last_mtime = 0;
 454
 455         if (progress > pack_to_stdout)
 456                 progress_state = start_progress("Writing objects", nr_result);
 457         written_list = xmalloc(nr_objects * sizeof(*written_list));
 458
 459         do {
 460                 unsigned char sha1[20];
 461                 char *pack_tmp_name = NULL;
 462
 463                 if (pack_to_stdout) {
 464                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 465                 } else {
 466                         char tmpname[PATH_MAX];
 467                         int fd;
 468                         snprintf(tmpname, sizeof(tmpname),
 469                                  "%s/pack/tmp_pack_XXXXXX", get_object_directory());
 470                         fd = xmkstemp(tmpname);
 471                         pack_tmp_name = xstrdup(tmpname);
 472                         f = sha1fd(fd, pack_tmp_name);
 473                 }
 474
 475                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
 476                 hdr.hdr_version = htonl(PACK_VERSION);
 477                 hdr.hdr_entries = htonl(nr_remaining);
 478                 sha1write(f, &hdr, sizeof(hdr));
 479                 offset = sizeof(hdr);
 480                 nr_written = 0;
 481                 for (; i < nr_objects; i++) {
 482                         if (!write_one(f, objects + i, &offset))
 483                                 break;
 484                         display_progress(progress_state, written);
 485                 }
 486
 487                 /*
 488                  * Did we write the wrong # entries in the header?
 489                  * If so, rewrite it like in fast-import
 490                  */
 491                 if (pack_to_stdout) {
 492                         sha1close(f, sha1, CSUM_CLOSE);
 493                 } else if (nr_written == nr_remaining) {
 494                         sha1close(f, sha1, CSUM_FSYNC);
 495                 } else {
 496                         int fd = sha1close(f, sha1, 0);
 497                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
 498                                                  nr_written, sha1, offset);
 499                         close(fd);
 500                 }
 501
 502                 if (!pack_to_stdout) {
 503                         mode_t mode = umask(0);
 504                         struct stat st;
 505                         char *idx_tmp_name, tmpname[PATH_MAX];
 506
 507                         umask(mode);
 508                         mode = 0444 & ~mode;
 509
 510                         idx_tmp_name = write_idx_file(NULL, written_list,
 511                                                       nr_written, sha1);
 512
 513                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 514                                  base_name, sha1_to_hex(sha1));
 515                         if (adjust_perm(pack_tmp_name, mode))
 516                                 die("unable to make temporary pack file readable: %s",
 517                                     strerror(errno));
 518                         if (rename(pack_tmp_name, tmpname))
 519                                 die("unable to rename temporary pack file: %s",
 520                                     strerror(errno));
 521
 522                         /*
 523                          * Packs are runtime accessed in their mtime
 524                          * order since newer packs are more likely to contain
 525                          * younger objects.  So if we are creating multiple
 526                          * packs then we should modify the mtime of later ones
 527                          * to preserve this property.
 528                          */
 529                         if (stat(tmpname, &st) < 0) {
 530                                 warning("failed to stat %s: %s",
 531                                         tmpname, strerror(errno));
 532                         } else if (!last_mtime) {
 533                                 last_mtime = st.st_mtime;
 534                         } else {
 535                                 struct utimbuf utb;
 536                                 utb.actime = st.st_atime;
 537                                 utb.modtime = --last_mtime;
 538                                 if (utime(tmpname, &utb) < 0)
 539                                         warning("failed utime() on %s: %s",
 540                                                 tmpname, strerror(errno));
 541                         }
 542
 543                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 544                                  base_name, sha1_to_hex(sha1));
 545                         if (adjust_perm(idx_tmp_name, mode))
 546                                 die("unable to make temporary index file readable: %s",
 547                                     strerror(errno));
 548                         if (rename(idx_tmp_name, tmpname))
 549                                 die("unable to rename temporary index file: %s",
 550                                     strerror(errno));
 551
 552                         free(idx_tmp_name);
 553                         free(pack_tmp_name);
 554                         puts(sha1_to_hex(sha1));
 555                 }
 556
 557                 /* mark written objects as written to previous pack */
 558                 for (j = 0; j < nr_written; j++) {
 559                         written_list[j]->offset = (off_t)-1;
 560                 }
 561                 nr_remaining -= nr_written;
 562         } while (nr_remaining && i < nr_objects);
 563
 564         free(written_list);
 565         stop_progress(&progress_state);
 566         if (written != nr_result)
 567                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
 568                         written, nr_result);
 569         /*
 570          * We have scanned through [0 ... i).  Since we have written
 571          * the correct number of objects,  the remaining [i ... nr_objects)
 572          * items must be either already written (due to out-of-order delta base)
 573          * or a preferred base.  Count those which are neither and complain if any.
 574          */
 575         for (j = 0; i < nr_objects; i++) {
 576                 struct object_entry *e = objects + i;
 577                 j += !e->idx.offset && !e->preferred_base;
 578         }
 579         if (j)
 580                 die("wrote %"PRIu32" objects as expected but %"PRIu32
 581                         " unwritten", written, j);
 582 }
 583
 584 static int locate_object_entry_hash(const unsigned char *sha1)
 585 {
 586         int i;
 587         unsigned int ui;
 588         memcpy(&ui, sha1, sizeof(unsigned int));
 589         i = ui % object_ix_hashsz;
 590         while (0 < object_ix[i]) {
 591                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 592                         return i;
 593                 if (++i == object_ix_hashsz)
 594                         i = 0;
 595         }
 596         return -1 - i;
 597 }
 598
 599 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 600 {
 601         int i;
 602
 603         if (!object_ix_hashsz)
 604                 return NULL;
 605
 606         i = locate_object_entry_hash(sha1);
 607         if (0 <= i)
 608                 return &objects[object_ix[i]-1];
 609         return NULL;
 610 }
 611
 612 static void rehash_objects(void)
 613 {
 614         uint32_t i;
 615         struct object_entry *oe;
 616
 617         object_ix_hashsz = nr_objects * 3;
 618         if (object_ix_hashsz < 1024)
 619                 object_ix_hashsz = 1024;
 620         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 621         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 622         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 623                 int ix = locate_object_entry_hash(oe->idx.sha1);
 624                 if (0 <= ix)
 625                         continue;
 626                 ix = -1 - ix;
 627                 object_ix[ix] = i + 1;
 628         }
 629 }
 630
 631 static unsigned name_hash(const char *name)
 632 {
 633         unsigned char c;
 634         unsigned hash = 0;
 635
 636         if (!name)
 637                 return 0;
 638
 639         /*
 640          * This effectively just creates a sortable number from the
 641          * last sixteen non-whitespace characters. Last characters
 642          * count "most", so things that end in ".c" sort together.
 643          */
 644         while ((c = *name++) != 0) {
 645                 if (isspace(c))
 646                         continue;
 647                 hash = (hash >> 2) + (c << 24);
 648         }
 649         return hash;
 650 }
 651
 652 static void setup_delta_attr_check(struct git_attr_check *check)
 653 {
 654         static struct git_attr *attr_delta;
 655
 656         if (!attr_delta)
 657                 attr_delta = git_attr("delta", 5);
 658
 659         check[0].attr = attr_delta;
 660 }
 661
 662 static int no_try_delta(const char *path)
 663 {
 664         struct git_attr_check check[1];
 665
 666         setup_delta_attr_check(check);
 667         if (git_checkattr(path, ARRAY_SIZE(check), check))
 668                 return 0;
 669         if (ATTR_FALSE(check->value))
 670                 return 1;
 671         return 0;
 672 }
 673
 674 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 675                             const char *name, int exclude)
 676 {
 677         struct object_entry *entry;
 678         struct packed_git *p, *found_pack = NULL;
 679         off_t found_offset = 0;
 680         int ix;
 681         unsigned hash = name_hash(name);
 682
 683         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 684         if (ix >= 0) {
 685                 if (exclude) {
 686                         entry = objects + object_ix[ix] - 1;
 687                         if (!entry->preferred_base)
 688                                 nr_result--;
 689                         entry->preferred_base = 1;
 690                 }
 691                 return 0;
 692         }
 693
 694         for (p = packed_git; p; p = p->next) {
 695                 off_t offset = find_pack_entry_one(sha1, p);
 696                 if (offset) {
 697                         if (!found_pack) {
 698                                 found_offset = offset;
 699                                 found_pack = p;
 700                         }
 701                         if (exclude)
 702                                 break;
 703                         if (incremental)
 704                                 return 0;
 705                         if (local && !p->pack_local)
 706                                 return 0;
 707                         if (ignore_packed_keep && p->pack_local && p->pack_keep)
 708                                 return 0;
 709                 }
 710         }
 711
 712         if (nr_objects >= nr_alloc) {
 713                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 714                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 715         }
 716
 717         entry = objects + nr_objects++;
 718         memset(entry, 0, sizeof(*entry));
 719         hashcpy(entry->idx.sha1, sha1);
 720         entry->hash = hash;
 721         if (type)
 722                 entry->type = type;
 723         if (exclude)
 724                 entry->preferred_base = 1;
 725         else
 726                 nr_result++;
 727         if (found_pack) {
 728                 entry->in_pack = found_pack;
 729                 entry->in_pack_offset = found_offset;
 730         }
 731
 732         if (object_ix_hashsz * 3 <= nr_objects * 4)
 733                 rehash_objects();
 734         else
 735                 object_ix[-1 - ix] = nr_objects;
 736
 737         display_progress(progress_state, nr_objects);
 738
 739         if (name && no_try_delta(name))
 740                 entry->no_try_delta = 1;
 741
 742         return 1;
 743 }
 744
 745 struct pbase_tree_cache {
 746         unsigned char sha1[20];
 747         int ref;
 748         int temporary;
 749         void *tree_data;
 750         unsigned long tree_size;
 751 };
 752
 753 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 754 static int pbase_tree_cache_ix(const unsigned char *sha1)
 755 {
 756         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 757 }
 758 static int pbase_tree_cache_ix_incr(int ix)
 759 {
 760         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 761 }
 762
 763 static struct pbase_tree {
 764         struct pbase_tree *next;
 765         /* This is a phony "cache" entry; we are not
 766          * going to evict it nor find it through _get()
 767          * mechanism -- this is for the toplevel node that
 768          * would almost always change with any commit.
 769          */
 770         struct pbase_tree_cache pcache;
 771 } *pbase_tree;
 772
 773 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 774 {
 775         struct pbase_tree_cache *ent, *nent;
 776         void *data;
 777         unsigned long size;
 778         enum object_type type;
 779         int neigh;
 780         int my_ix = pbase_tree_cache_ix(sha1);
 781         int available_ix = -1;
 782
 783         /* pbase-tree-cache acts as a limited hashtable.
 784          * your object will be found at your index or within a few
 785          * slots after that slot if it is cached.
 786          */
 787         for (neigh = 0; neigh < 8; neigh++) {
 788                 ent = pbase_tree_cache[my_ix];
 789                 if (ent && !hashcmp(ent->sha1, sha1)) {
 790                         ent->ref++;
 791                         return ent;
 792                 }
 793                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 794                          ((0 <= available_ix) &&
 795                           (!ent && pbase_tree_cache[available_ix])))
 796                         available_ix = my_ix;
 797                 if (!ent)
 798                         break;
 799                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 800         }
 801
 802         /* Did not find one.  Either we got a bogus request or
 803          * we need to read and perhaps cache.
 804          */
 805         data = read_sha1_file(sha1, &type, &size);
 806         if (!data)
 807                 return NULL;
 808         if (type != OBJ_TREE) {
 809                 free(data);
 810                 return NULL;
 811         }
 812
 813         /* We need to either cache or return a throwaway copy */
 814
 815         if (available_ix < 0)
 816                 ent = NULL;
 817         else {
 818                 ent = pbase_tree_cache[available_ix];
 819                 my_ix = available_ix;
 820         }
 821
 822         if (!ent) {
 823                 nent = xmalloc(sizeof(*nent));
 824                 nent->temporary = (available_ix < 0);
 825         }
 826         else {
 827                 /* evict and reuse */
 828                 free(ent->tree_data);
 829                 nent = ent;
 830         }
 831         hashcpy(nent->sha1, sha1);
 832         nent->tree_data = data;
 833         nent->tree_size = size;
 834         nent->ref = 1;
 835         if (!nent->temporary)
 836                 pbase_tree_cache[my_ix] = nent;
 837         return nent;
 838 }
 839
 840 static void pbase_tree_put(struct pbase_tree_cache *cache)
 841 {
 842         if (!cache->temporary) {
 843                 cache->ref--;
 844                 return;
 845         }
 846         free(cache->tree_data);
 847         free(cache);
 848 }
 849
 850 static int name_cmp_len(const char *name)
 851 {
 852         int i;
 853         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 854                 ;
 855         return i;
 856 }
 857
 858 static void add_pbase_object(struct tree_desc *tree,
 859                              const char *name,
 860                              int cmplen,
 861                              const char *fullname)
 862 {
 863         struct name_entry entry;
 864         int cmp;
 865
 866         while (tree_entry(tree,&entry)) {
 867                 if (S_ISGITLINK(entry.mode))
 868                         continue;
 869                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 870                       memcmp(name, entry.path, cmplen);
 871                 if (cmp > 0)
 872                         continue;
 873                 if (cmp < 0)
 874                         return;
 875                 if (name[cmplen] != '/') {
 876                         add_object_entry(entry.sha1,
 877                                          object_type(entry.mode),
 878                                          fullname, 1);
 879                         return;
 880                 }
 881                 if (S_ISDIR(entry.mode)) {
 882                         struct tree_desc sub;
 883                         struct pbase_tree_cache *tree;
 884                         const char *down = name+cmplen+1;
 885                         int downlen = name_cmp_len(down);
 886
 887                         tree = pbase_tree_get(entry.sha1);
 888                         if (!tree)
 889                                 return;
 890                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 891
 892                         add_pbase_object(&sub, down, downlen, fullname);
 893                         pbase_tree_put(tree);
 894                 }
 895         }
 896 }
 897
 898 static unsigned *done_pbase_paths;
 899 static int done_pbase_paths_num;
 900 static int done_pbase_paths_alloc;
 901 static int done_pbase_path_pos(unsigned hash)
 902 {
 903         int lo = 0;
 904         int hi = done_pbase_paths_num;
 905         while (lo < hi) {
 906                 int mi = (hi + lo) / 2;
 907                 if (done_pbase_paths[mi] == hash)
 908                         return mi;
 909                 if (done_pbase_paths[mi] < hash)
 910                         hi = mi;
 911                 else
 912                         lo = mi + 1;
 913         }
 914         return -lo-1;
 915 }
 916
 917 static int check_pbase_path(unsigned hash)
 918 {
 919         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 920         if (0 <= pos)
 921                 return 1;
 922         pos = -pos - 1;
 923         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 924                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 925                 done_pbase_paths = xrealloc(done_pbase_paths,
 926                                             done_pbase_paths_alloc *
 927                                             sizeof(unsigned));
 928         }
 929         done_pbase_paths_num++;
 930         if (pos < done_pbase_paths_num)
 931                 memmove(done_pbase_paths + pos + 1,
 932                         done_pbase_paths + pos,
 933                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 934         done_pbase_paths[pos] = hash;
 935         return 0;
 936 }
 937
 938 static void add_preferred_base_object(const char *name)
 939 {
 940         struct pbase_tree *it;
 941         int cmplen;
 942         unsigned hash = name_hash(name);
 943
 944         if (!num_preferred_base || check_pbase_path(hash))
 945                 return;
 946
 947         cmplen = name_cmp_len(name);
 948         for (it = pbase_tree; it; it = it->next) {
 949                 if (cmplen == 0) {
 950                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 951                 }
 952                 else {
 953                         struct tree_desc tree;
 954                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 955                         add_pbase_object(&tree, name, cmplen, name);
 956                 }
 957         }
 958 }
 959
 960 static void add_preferred_base(unsigned char *sha1)
 961 {
 962         struct pbase_tree *it;
 963         void *data;
 964         unsigned long size;
 965         unsigned char tree_sha1[20];
 966
 967         if (window <= num_preferred_base++)
 968                 return;
 969
 970         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 971         if (!data)
 972                 return;
 973
 974         for (it = pbase_tree; it; it = it->next) {
 975                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 976                         free(data);
 977                         return;
 978                 }
 979         }
 980
 981         it = xcalloc(1, sizeof(*it));
 982         it->next = pbase_tree;
 983         pbase_tree = it;
 984
 985         hashcpy(it->pcache.sha1, tree_sha1);
 986         it->pcache.tree_data = data;
 987         it->pcache.tree_size = size;
 988 }
 989
 990 static void check_object(struct object_entry *entry)
 991 {
 992         if (entry->in_pack) {
 993                 struct packed_git *p = entry->in_pack;
 994                 struct pack_window *w_curs = NULL;
 995                 const unsigned char *base_ref = NULL;
 996                 struct object_entry *base_entry;
 997                 unsigned long used, used_0;
 998                 unsigned int avail;
 999                 off_t ofs;
1000                 unsigned char *buf, c;
1001
1002                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1003
1004                 /*
1005                  * We want in_pack_type even if we do not reuse delta
1006                  * since non-delta representations could still be reused.
1007                  */
1008                 used = unpack_object_header_gently(buf, avail,
1009                                                    &entry->in_pack_type,
1010                                                    &entry->size);
1011
1012                 /*
1013                  * Determine if this is a delta and if so whether we can
1014                  * reuse it or not.  Otherwise let's find out as cheaply as
1015                  * possible what the actual type and size for this object is.
1016                  */
1017                 switch (entry->in_pack_type) {
1018                 default:
1019                         /* Not a delta hence we've already got all we need. */
1020                         entry->type = entry->in_pack_type;
1021                         entry->in_pack_header_size = used;
1022                         unuse_pack(&w_curs);
1023                         return;
1024                 case OBJ_REF_DELTA:
1025                         if (reuse_delta && !entry->preferred_base)
1026                                 base_ref = use_pack(p, &w_curs,
1027                                                 entry->in_pack_offset + used, NULL);
1028                         entry->in_pack_header_size = used + 20;
1029                         break;
1030                 case OBJ_OFS_DELTA:
1031                         buf = use_pack(p, &w_curs,
1032                                        entry->in_pack_offset + used, NULL);
1033                         used_0 = 0;
1034                         c = buf[used_0++];
1035                         ofs = c & 127;
1036                         while (c & 128) {
1037                                 ofs += 1;
1038                                 if (!ofs || MSB(ofs, 7))
1039                                         die("delta base offset overflow in pack for %s",
1040                                             sha1_to_hex(entry->idx.sha1));
1041                                 c = buf[used_0++];
1042                                 ofs = (ofs << 7) + (c & 127);
1043                         }
1044                         if (ofs >= entry->in_pack_offset)
1045                                 die("delta base offset out of bound for %s",
1046                                     sha1_to_hex(entry->idx.sha1));
1047                         ofs = entry->in_pack_offset - ofs;
1048                         if (reuse_delta && !entry->preferred_base) {
1049                                 struct revindex_entry *revidx;
1050                                 revidx = find_pack_revindex(p, ofs);
1051                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1052                         }
1053                         entry->in_pack_header_size = used + used_0;
1054                         break;
1055                 }
1056
1057                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1058                         /*
1059                          * If base_ref was set above that means we wish to
1060                          * reuse delta data, and we even found that base
1061                          * in the list of objects we want to pack. Goodie!
1062                          *
1063                          * Depth value does not matter - find_deltas() will
1064                          * never consider reused delta as the base object to
1065                          * deltify other objects against, in order to avoid
1066                          * circular deltas.
1067                          */
1068                         entry->type = entry->in_pack_type;
1069                         entry->delta = base_entry;
1070                         entry->delta_sibling = base_entry->delta_child;
1071                         base_entry->delta_child = entry;
1072                         unuse_pack(&w_curs);
1073                         return;
1074                 }
1075
1076                 if (entry->type) {
1077                         /*
1078                          * This must be a delta and we already know what the
1079                          * final object type is.  Let's extract the actual
1080                          * object size from the delta header.
1081                          */
1082                         entry->size = get_size_from_delta(p, &w_curs,
1083                                         entry->in_pack_offset + entry->in_pack_header_size);
1084                         unuse_pack(&w_curs);
1085                         return;
1086                 }
1087
1088                 /*
1089                  * No choice but to fall back to the recursive delta walk
1090                  * with sha1_object_info() to find about the object type
1091                  * at this point...
1092                  */
1093                 unuse_pack(&w_curs);
1094         }
1095
1096         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1097         /*
1098          * The error condition is checked in prepare_pack().  This is
1099          * to permit a missing preferred base object to be ignored
1100          * as a preferred base.  Doing so can result in a larger
1101          * pack file, but the transfer will still take place.
1102          */
1103 }
1104
1105 static int pack_offset_sort(const void *_a, const void *_b)
1106 {
1107         const struct object_entry *a = *(struct object_entry **)_a;
1108         const struct object_entry *b = *(struct object_entry **)_b;
1109
1110         /* avoid filesystem trashing with loose objects */
1111         if (!a->in_pack && !b->in_pack)
1112                 return hashcmp(a->idx.sha1, b->idx.sha1);
1113
1114         if (a->in_pack < b->in_pack)
1115                 return -1;
1116         if (a->in_pack > b->in_pack)
1117                 return 1;
1118         return a->in_pack_offset < b->in_pack_offset ? -1 :
1119                         (a->in_pack_offset > b->in_pack_offset);
1120 }
1121
1122 static void get_object_details(void)
1123 {
1124         uint32_t i;
1125         struct object_entry **sorted_by_offset;
1126
1127         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1128         for (i = 0; i < nr_objects; i++)
1129                 sorted_by_offset[i] = objects + i;
1130         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1131
1132         for (i = 0; i < nr_objects; i++)
1133                 check_object(sorted_by_offset[i]);
1134
1135         free(sorted_by_offset);
1136 }
1137
1138 /*
1139  * We search for deltas in a list sorted by type, by filename hash, and then
1140  * by size, so that we see progressively smaller and smaller files.
1141  * That's because we prefer deltas to be from the bigger file
1142  * to the smaller -- deletes are potentially cheaper, but perhaps
1143  * more importantly, the bigger file is likely the more recent
1144  * one.  The deepest deltas are therefore the oldest objects which are
1145  * less susceptible to be accessed often.
1146  */
1147 static int type_size_sort(const void *_a, const void *_b)
1148 {
1149         const struct object_entry *a = *(struct object_entry **)_a;
1150         const struct object_entry *b = *(struct object_entry **)_b;
1151
1152         if (a->type > b->type)
1153                 return -1;
1154         if (a->type < b->type)
1155                 return 1;
1156         if (a->hash > b->hash)
1157                 return -1;
1158         if (a->hash < b->hash)
1159                 return 1;
1160         if (a->preferred_base > b->preferred_base)
1161                 return -1;
1162         if (a->preferred_base < b->preferred_base)
1163                 return 1;
1164         if (a->size > b->size)
1165                 return -1;
1166         if (a->size < b->size)
1167                 return 1;
1168         return a < b ? -1 : (a > b);  /* newest first */
1169 }
1170
1171 struct unpacked {
1172         struct object_entry *entry;
1173         void *data;
1174         struct delta_index *index;
1175         unsigned depth;
1176 };
1177
1178 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1179                            unsigned long delta_size)
1180 {
1181         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1182                 return 0;
1183
1184         if (delta_size < cache_max_small_delta_size)
1185                 return 1;
1186
1187         /* cache delta, if objects are large enough compared to delta size */
1188         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1189                 return 1;
1190
1191         return 0;
1192 }
1193
1194 #ifdef THREADED_DELTA_SEARCH
1195
1196 static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1197 #define read_lock()             pthread_mutex_lock(&read_mutex)
1198 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1199
1200 static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1201 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1202 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1203
1204 static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1205 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1206 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1207
1208 #else
1209
1210 #define read_lock()             (void)0
1211 #define read_unlock()           (void)0
1212 #define cache_lock()            (void)0
1213 #define cache_unlock()          (void)0
1214 #define progress_lock()         (void)0
1215 #define progress_unlock()       (void)0
1216
1217 #endif
1218
1219 static int try_delta(struct unpacked *trg, struct unpacked *src,
1220                      unsigned max_depth, unsigned long *mem_usage)
1221 {
1222         struct object_entry *trg_entry = trg->entry;
1223         struct object_entry *src_entry = src->entry;
1224         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1225         unsigned ref_depth;
1226         enum object_type type;
1227         void *delta_buf;
1228
1229         /* Don't bother doing diffs between different types */
1230         if (trg_entry->type != src_entry->type)
1231                 return -1;
1232
1233         /*
1234          * We do not bother to try a delta that we discarded
1235          * on an earlier try, but only when reusing delta data.
1236          */
1237         if (reuse_delta && trg_entry->in_pack &&
1238             trg_entry->in_pack == src_entry->in_pack &&
1239             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1240             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1241                 return 0;
1242
1243         /* Let's not bust the allowed depth. */
1244         if (src->depth >= max_depth)
1245                 return 0;
1246
1247         /* Now some size filtering heuristics. */
1248         trg_size = trg_entry->size;
1249         if (!trg_entry->delta) {
1250                 max_size = trg_size/2 - 20;
1251                 ref_depth = 1;
1252         } else {
1253                 max_size = trg_entry->delta_size;
1254                 ref_depth = trg->depth;
1255         }
1256         max_size = max_size * (max_depth - src->depth) /
1257                                                 (max_depth - ref_depth + 1);
1258         if (max_size == 0)
1259                 return 0;
1260         src_size = src_entry->size;
1261         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1262         if (sizediff >= max_size)
1263                 return 0;
1264         if (trg_size < src_size / 32)
1265                 return 0;
1266
1267         /* Load data if not already done */
1268         if (!trg->data) {
1269                 read_lock();
1270                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1271                 read_unlock();
1272                 if (!trg->data)
1273                         die("object %s cannot be read",
1274                             sha1_to_hex(trg_entry->idx.sha1));
1275                 if (sz != trg_size)
1276                         die("object %s inconsistent object length (%lu vs %lu)",
1277                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1278                 *mem_usage += sz;
1279         }
1280         if (!src->data) {
1281                 read_lock();
1282                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1283                 read_unlock();
1284                 if (!src->data)
1285                         die("object %s cannot be read",
1286                             sha1_to_hex(src_entry->idx.sha1));
1287                 if (sz != src_size)
1288                         die("object %s inconsistent object length (%lu vs %lu)",
1289                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1290                 *mem_usage += sz;
1291         }
1292         if (!src->index) {
1293                 src->index = create_delta_index(src->data, src_size);
1294                 if (!src->index) {
1295                         static int warned = 0;
1296                         if (!warned++)
1297                                 warning("suboptimal pack - out of memory");
1298                         return 0;
1299                 }
1300                 *mem_usage += sizeof_delta_index(src->index);
1301         }
1302
1303         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1304         if (!delta_buf)
1305                 return 0;
1306
1307         if (trg_entry->delta) {
1308                 /* Prefer only shallower same-sized deltas. */
1309                 if (delta_size == trg_entry->delta_size &&
1310                     src->depth + 1 >= trg->depth) {
1311                         free(delta_buf);
1312                         return 0;
1313                 }
1314         }
1315
1316         /*
1317          * Handle memory allocation outside of the cache
1318          * accounting lock.  Compiler will optimize the strangeness
1319          * away when THREADED_DELTA_SEARCH is not defined.
1320          */
1321         free(trg_entry->delta_data);
1322         cache_lock();
1323         if (trg_entry->delta_data) {
1324                 delta_cache_size -= trg_entry->delta_size;
1325                 trg_entry->delta_data = NULL;
1326         }
1327         if (delta_cacheable(src_size, trg_size, delta_size)) {
1328                 delta_cache_size += delta_size;
1329                 cache_unlock();
1330                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1331         } else {
1332                 cache_unlock();
1333                 free(delta_buf);
1334         }
1335
1336         trg_entry->delta = src_entry;
1337         trg_entry->delta_size = delta_size;
1338         trg->depth = src->depth + 1;
1339
1340         return 1;
1341 }
1342
1343 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1344 {
1345         struct object_entry *child = me->delta_child;
1346         unsigned int m = n;
1347         while (child) {
1348                 unsigned int c = check_delta_limit(child, n + 1);
1349                 if (m < c)
1350                         m = c;
1351                 child = child->delta_sibling;
1352         }
1353         return m;
1354 }
1355
1356 static unsigned long free_unpacked(struct unpacked *n)
1357 {
1358         unsigned long freed_mem = sizeof_delta_index(n->index);
1359         free_delta_index(n->index);
1360         n->index = NULL;
1361         if (n->data) {
1362                 freed_mem += n->entry->size;
1363                 free(n->data);
1364                 n->data = NULL;
1365         }
1366         n->entry = NULL;
1367         n->depth = 0;
1368         return freed_mem;
1369 }
1370
1371 static void find_deltas(struct object_entry **list, unsigned *list_size,
1372                         int window, int depth, unsigned *processed)
1373 {
1374         uint32_t i, idx = 0, count = 0;
1375         unsigned int array_size = window * sizeof(struct unpacked);
1376         struct unpacked *array;
1377         unsigned long mem_usage = 0;
1378
1379         array = xmalloc(array_size);
1380         memset(array, 0, array_size);
1381
1382         for (;;) {
1383                 struct object_entry *entry;
1384                 struct unpacked *n = array + idx;
1385                 int j, max_depth, best_base = -1;
1386
1387                 progress_lock();
1388                 if (!*list_size) {
1389                         progress_unlock();
1390                         break;
1391                 }
1392                 entry = *list++;
1393                 (*list_size)--;
1394                 if (!entry->preferred_base) {
1395                         (*processed)++;
1396                         display_progress(progress_state, *processed);
1397                 }
1398                 progress_unlock();
1399
1400                 mem_usage -= free_unpacked(n);
1401                 n->entry = entry;
1402
1403                 while (window_memory_limit &&
1404                        mem_usage > window_memory_limit &&
1405                        count > 1) {
1406                         uint32_t tail = (idx + window - count) % window;
1407                         mem_usage -= free_unpacked(array + tail);
1408                         count--;
1409                 }
1410
1411                 /* We do not compute delta to *create* objects we are not
1412                  * going to pack.
1413                  */
1414                 if (entry->preferred_base)
1415                         goto next;
1416
1417                 /*
1418                  * If the current object is at pack edge, take the depth the
1419                  * objects that depend on the current object into account
1420                  * otherwise they would become too deep.
1421                  */
1422                 max_depth = depth;
1423                 if (entry->delta_child) {
1424                         max_depth -= check_delta_limit(entry, 0);
1425                         if (max_depth <= 0)
1426                                 goto next;
1427                 }
1428
1429                 j = window;
1430                 while (--j > 0) {
1431                         int ret;
1432                         uint32_t other_idx = idx + j;
1433                         struct unpacked *m;
1434                         if (other_idx >= window)
1435                                 other_idx -= window;
1436                         m = array + other_idx;
1437                         if (!m->entry)
1438                                 break;
1439                         ret = try_delta(n, m, max_depth, &mem_usage);
1440                         if (ret < 0)
1441                                 break;
1442                         else if (ret > 0)
1443                                 best_base = other_idx;
1444                 }
1445
1446                 /*
1447                  * If we decided to cache the delta data, then it is best
1448                  * to compress it right away.  First because we have to do
1449                  * it anyway, and doing it here while we're threaded will
1450                  * save a lot of time in the non threaded write phase,
1451                  * as well as allow for caching more deltas within
1452                  * the same cache size limit.
1453                  * ...
1454                  * But only if not writing to stdout, since in that case
1455                  * the network is most likely throttling writes anyway,
1456                  * and therefore it is best to go to the write phase ASAP
1457                  * instead, as we can afford spending more time compressing
1458                  * between writes at that moment.
1459                  */
1460                 if (entry->delta_data && !pack_to_stdout) {
1461                         entry->z_delta_size = do_compress(&entry->delta_data,
1462                                                           entry->delta_size);
1463                         cache_lock();
1464                         delta_cache_size -= entry->delta_size;
1465                         delta_cache_size += entry->z_delta_size;
1466                         cache_unlock();
1467                 }
1468
1469                 /* if we made n a delta, and if n is already at max
1470                  * depth, leaving it in the window is pointless.  we
1471                  * should evict it first.
1472                  */
1473                 if (entry->delta && max_depth <= n->depth)
1474                         continue;
1475
1476                 /*
1477                  * Move the best delta base up in the window, after the
1478                  * currently deltified object, to keep it longer.  It will
1479                  * be the first base object to be attempted next.
1480                  */
1481                 if (entry->delta) {
1482                         struct unpacked swap = array[best_base];
1483                         int dist = (window + idx - best_base) % window;
1484                         int dst = best_base;
1485                         while (dist--) {
1486                                 int src = (dst + 1) % window;
1487                                 array[dst] = array[src];
1488                                 dst = src;
1489                         }
1490                         array[dst] = swap;
1491                 }
1492
1493                 next:
1494                 idx++;
1495                 if (count + 1 < window)
1496                         count++;
1497                 if (idx >= window)
1498                         idx = 0;
1499         }
1500
1501         for (i = 0; i < window; ++i) {
1502                 free_delta_index(array[i].index);
1503                 free(array[i].data);
1504         }
1505         free(array);
1506 }
1507
1508 #ifdef THREADED_DELTA_SEARCH
1509
1510 /*
1511  * The main thread waits on the condition that (at least) one of the workers
1512  * has stopped working (which is indicated in the .working member of
1513  * struct thread_params).
1514  * When a work thread has completed its work, it sets .working to 0 and
1515  * signals the main thread and waits on the condition that .data_ready
1516  * becomes 1.
1517  */
1518
1519 struct thread_params {
1520         pthread_t thread;
1521         struct object_entry **list;
1522         unsigned list_size;
1523         unsigned remaining;
1524         int window;
1525         int depth;
1526         int working;
1527         int data_ready;
1528         pthread_mutex_t mutex;
1529         pthread_cond_t cond;
1530         unsigned *processed;
1531 };
1532
1533 static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
1534
1535 static void *threaded_find_deltas(void *arg)
1536 {
1537         struct thread_params *me = arg;
1538
1539         while (me->remaining) {
1540                 find_deltas(me->list, &me->remaining,
1541                             me->window, me->depth, me->processed);
1542
1543                 progress_lock();
1544                 me->working = 0;
1545                 pthread_cond_signal(&progress_cond);
1546                 progress_unlock();
1547
1548                 /*
1549                  * We must not set ->data_ready before we wait on the
1550                  * condition because the main thread may have set it to 1
1551                  * before we get here. In order to be sure that new
1552                  * work is available if we see 1 in ->data_ready, it
1553                  * was initialized to 0 before this thread was spawned
1554                  * and we reset it to 0 right away.
1555                  */
1556                 pthread_mutex_lock(&me->mutex);
1557                 while (!me->data_ready)
1558                         pthread_cond_wait(&me->cond, &me->mutex);
1559                 me->data_ready = 0;
1560                 pthread_mutex_unlock(&me->mutex);
1561         }
1562         /* leave ->working 1 so that this doesn't get more work assigned */
1563         return NULL;
1564 }
1565
1566 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1567                            int window, int depth, unsigned *processed)
1568 {
1569         struct thread_params p[delta_search_threads];
1570         int i, ret, active_threads = 0;
1571
1572         if (delta_search_threads <= 1) {
1573                 find_deltas(list, &list_size, window, depth, processed);
1574                 return;
1575         }
1576
1577         /* Partition the work amongst work threads. */
1578         for (i = 0; i < delta_search_threads; i++) {
1579                 unsigned sub_size = list_size / (delta_search_threads - i);
1580
1581                 p[i].window = window;
1582                 p[i].depth = depth;
1583                 p[i].processed = processed;
1584                 p[i].working = 1;
1585                 p[i].data_ready = 0;
1586
1587                 /* try to split chunks on "path" boundaries */
1588                 while (sub_size && sub_size < list_size &&
1589                        list[sub_size]->hash &&
1590                        list[sub_size]->hash == list[sub_size-1]->hash)
1591                         sub_size++;
1592
1593                 p[i].list = list;
1594                 p[i].list_size = sub_size;
1595                 p[i].remaining = sub_size;
1596
1597                 list += sub_size;
1598                 list_size -= sub_size;
1599         }
1600
1601         /* Start work threads. */
1602         for (i = 0; i < delta_search_threads; i++) {
1603                 if (!p[i].list_size)
1604                         continue;
1605                 pthread_mutex_init(&p[i].mutex, NULL);
1606                 pthread_cond_init(&p[i].cond, NULL);
1607                 ret = pthread_create(&p[i].thread, NULL,
1608                                      threaded_find_deltas, &p[i]);
1609                 if (ret)
1610                         die("unable to create thread: %s", strerror(ret));
1611                 active_threads++;
1612         }
1613
1614         /*
1615          * Now let's wait for work completion.  Each time a thread is done
1616          * with its work, we steal half of the remaining work from the
1617          * thread with the largest number of unprocessed objects and give
1618          * it to that newly idle thread.  This ensure good load balancing
1619          * until the remaining object list segments are simply too short
1620          * to be worth splitting anymore.
1621          */
1622         while (active_threads) {
1623                 struct thread_params *target = NULL;
1624                 struct thread_params *victim = NULL;
1625                 unsigned sub_size = 0;
1626
1627                 progress_lock();
1628                 for (;;) {
1629                         for (i = 0; !target && i < delta_search_threads; i++)
1630                                 if (!p[i].working)
1631                                         target = &p[i];
1632                         if (target)
1633                                 break;
1634                         pthread_cond_wait(&progress_cond, &progress_mutex);
1635                 }
1636
1637                 for (i = 0; i < delta_search_threads; i++)
1638                         if (p[i].remaining > 2*window &&
1639                             (!victim || victim->remaining < p[i].remaining))
1640                                 victim = &p[i];
1641                 if (victim) {
1642                         sub_size = victim->remaining / 2;
1643                         list = victim->list + victim->list_size - sub_size;
1644                         while (sub_size && list[0]->hash &&
1645                                list[0]->hash == list[-1]->hash) {
1646                                 list++;
1647                                 sub_size--;
1648                         }
1649                         if (!sub_size) {
1650                                 /*
1651                                  * It is possible for some "paths" to have
1652                                  * so many objects that no hash boundary
1653                                  * might be found.  Let's just steal the
1654                                  * exact half in that case.
1655                                  */
1656                                 sub_size = victim->remaining / 2;
1657                                 list -= sub_size;
1658                         }
1659                         target->list = list;
1660                         victim->list_size -= sub_size;
1661                         victim->remaining -= sub_size;
1662                 }
1663                 target->list_size = sub_size;
1664                 target->remaining = sub_size;
1665                 target->working = 1;
1666                 progress_unlock();
1667
1668                 pthread_mutex_lock(&target->mutex);
1669                 target->data_ready = 1;
1670                 pthread_cond_signal(&target->cond);
1671                 pthread_mutex_unlock(&target->mutex);
1672
1673                 if (!sub_size) {
1674                         pthread_join(target->thread, NULL);
1675                         pthread_cond_destroy(&target->cond);
1676                         pthread_mutex_destroy(&target->mutex);
1677                         active_threads--;
1678                 }
1679         }
1680 }
1681
1682 #else
1683 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1684 #endif
1685
1686 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1687 {
1688         unsigned char peeled[20];
1689
1690         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1691             !peel_ref(path, peeled)        && /* peelable? */
1692             !is_null_sha1(peeled)          && /* annotated tag? */
1693             locate_object_entry(peeled))      /* object packed? */
1694                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1695         return 0;
1696 }
1697
1698 static void prepare_pack(int window, int depth)
1699 {
1700         struct object_entry **delta_list;
1701         uint32_t i, nr_deltas;
1702         unsigned n;
1703
1704         get_object_details();
1705
1706         if (!nr_objects || !window || !depth)
1707                 return;
1708
1709         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1710         nr_deltas = n = 0;
1711
1712         for (i = 0; i < nr_objects; i++) {
1713                 struct object_entry *entry = objects + i;
1714
1715                 if (entry->delta)
1716                         /* This happens if we decided to reuse existing
1717                          * delta from a pack.  "reuse_delta &&" is implied.
1718                          */
1719                         continue;
1720
1721                 if (entry->size < 50)
1722                         continue;
1723
1724                 if (entry->no_try_delta)
1725                         continue;
1726
1727                 if (!entry->preferred_base) {
1728                         nr_deltas++;
1729                         if (entry->type < 0)
1730                                 die("unable to get type of object %s",
1731                                     sha1_to_hex(entry->idx.sha1));
1732                 }
1733
1734                 delta_list[n++] = entry;
1735         }
1736
1737         if (nr_deltas && n > 1) {
1738                 unsigned nr_done = 0;
1739                 if (progress)
1740                         progress_state = start_progress("Compressing objects",
1741                                                         nr_deltas);
1742                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1743                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1744                 stop_progress(&progress_state);
1745                 if (nr_done != nr_deltas)
1746                         die("inconsistency with delta count");
1747         }
1748         free(delta_list);
1749 }
1750
1751 static int git_pack_config(const char *k, const char *v, void *cb)
1752 {
1753         if(!strcmp(k, "pack.window")) {
1754                 window = git_config_int(k, v);
1755                 return 0;
1756         }
1757         if (!strcmp(k, "pack.windowmemory")) {
1758                 window_memory_limit = git_config_ulong(k, v);
1759                 return 0;
1760         }
1761         if (!strcmp(k, "pack.depth")) {
1762                 depth = git_config_int(k, v);
1763                 return 0;
1764         }
1765         if (!strcmp(k, "pack.compression")) {
1766                 int level = git_config_int(k, v);
1767                 if (level == -1)
1768                         level = Z_DEFAULT_COMPRESSION;
1769                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1770                         die("bad pack compression level %d", level);
1771                 pack_compression_level = level;
1772                 pack_compression_seen = 1;
1773                 return 0;
1774         }
1775         if (!strcmp(k, "pack.deltacachesize")) {
1776                 max_delta_cache_size = git_config_int(k, v);
1777                 return 0;
1778         }
1779         if (!strcmp(k, "pack.deltacachelimit")) {
1780                 cache_max_small_delta_size = git_config_int(k, v);
1781                 return 0;
1782         }
1783         if (!strcmp(k, "pack.threads")) {
1784                 delta_search_threads = git_config_int(k, v);
1785                 if (delta_search_threads < 0)
1786                         die("invalid number of threads specified (%d)",
1787                             delta_search_threads);
1788 #ifndef THREADED_DELTA_SEARCH
1789                 if (delta_search_threads != 1)
1790                         warning("no threads support, ignoring %s", k);
1791 #endif
1792                 return 0;
1793         }
1794         if (!strcmp(k, "pack.indexversion")) {
1795                 pack_idx_default_version = git_config_int(k, v);
1796                 if (pack_idx_default_version > 2)
1797                         die("bad pack.indexversion=%"PRIu32,
1798                                 pack_idx_default_version);
1799                 return 0;
1800         }
1801         if (!strcmp(k, "pack.packsizelimit")) {
1802                 pack_size_limit_cfg = git_config_ulong(k, v);
1803                 return 0;
1804         }
1805         return git_default_config(k, v, cb);
1806 }
1807
1808 static void read_object_list_from_stdin(void)
1809 {
1810         char line[40 + 1 + PATH_MAX + 2];
1811         unsigned char sha1[20];
1812
1813         for (;;) {
1814                 if (!fgets(line, sizeof(line), stdin)) {
1815                         if (feof(stdin))
1816                                 break;
1817                         if (!ferror(stdin))
1818                                 die("fgets returned NULL, not EOF, not error!");
1819                         if (errno != EINTR)
1820                                 die("fgets: %s", strerror(errno));
1821                         clearerr(stdin);
1822                         continue;
1823                 }
1824                 if (line[0] == '-') {
1825                         if (get_sha1_hex(line+1, sha1))
1826                                 die("expected edge sha1, got garbage:\n %s",
1827                                     line);
1828                         add_preferred_base(sha1);
1829                         continue;
1830                 }
1831                 if (get_sha1_hex(line, sha1))
1832                         die("expected sha1, got garbage:\n %s", line);
1833
1834                 add_preferred_base_object(line+41);
1835                 add_object_entry(sha1, 0, line+41, 0);
1836         }
1837 }
1838
1839 #define OBJECT_ADDED (1u<<20)
1840
1841 static void show_commit(struct commit *commit)
1842 {
1843         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1844         commit->object.flags |= OBJECT_ADDED;
1845 }
1846
1847 static void show_object(struct object_array_entry *p)
1848 {
1849         add_preferred_base_object(p->name);
1850         add_object_entry(p->item->sha1, p->item->type, p->name, 0);
1851         p->item->flags |= OBJECT_ADDED;
1852 }
1853
1854 static void show_edge(struct commit *commit)
1855 {
1856         add_preferred_base(commit->object.sha1);
1857 }
1858
1859 struct in_pack_object {
1860         off_t offset;
1861         struct object *object;
1862 };
1863
1864 struct in_pack {
1865         int alloc;
1866         int nr;
1867         struct in_pack_object *array;
1868 };
1869
1870 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1871 {
1872         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1873         in_pack->array[in_pack->nr].object = object;
1874         in_pack->nr++;
1875 }
1876
1877 /*
1878  * Compare the objects in the offset order, in order to emulate the
1879  * "git rev-list --objects" output that produced the pack originally.
1880  */
1881 static int ofscmp(const void *a_, const void *b_)
1882 {
1883         struct in_pack_object *a = (struct in_pack_object *)a_;
1884         struct in_pack_object *b = (struct in_pack_object *)b_;
1885
1886         if (a->offset < b->offset)
1887                 return -1;
1888         else if (a->offset > b->offset)
1889                 return 1;
1890         else
1891                 return hashcmp(a->object->sha1, b->object->sha1);
1892 }
1893
1894 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1895 {
1896         struct packed_git *p;
1897         struct in_pack in_pack;
1898         uint32_t i;
1899
1900         memset(&in_pack, 0, sizeof(in_pack));
1901
1902         for (p = packed_git; p; p = p->next) {
1903                 const unsigned char *sha1;
1904                 struct object *o;
1905
1906                 for (i = 0; i < revs->num_ignore_packed; i++) {
1907                         if (matches_pack_name(p, revs->ignore_packed[i]))
1908                                 break;
1909                 }
1910                 if (revs->num_ignore_packed <= i)
1911                         continue;
1912                 if (open_pack_index(p))
1913                         die("cannot open pack index");
1914
1915                 ALLOC_GROW(in_pack.array,
1916                            in_pack.nr + p->num_objects,
1917                            in_pack.alloc);
1918
1919                 for (i = 0; i < p->num_objects; i++) {
1920                         sha1 = nth_packed_object_sha1(p, i);
1921                         o = lookup_unknown_object(sha1);
1922                         if (!(o->flags & OBJECT_ADDED))
1923                                 mark_in_pack_object(o, p, &in_pack);
1924                         o->flags |= OBJECT_ADDED;
1925                 }
1926         }
1927
1928         if (in_pack.nr) {
1929                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
1930                       ofscmp);
1931                 for (i = 0; i < in_pack.nr; i++) {
1932                         struct object *o = in_pack.array[i].object;
1933                         add_object_entry(o->sha1, o->type, "", 0);
1934                 }
1935         }
1936         free(in_pack.array);
1937 }
1938
1939 static void loosen_unused_packed_objects(struct rev_info *revs)
1940 {
1941         struct packed_git *p;
1942         uint32_t i;
1943         const unsigned char *sha1;
1944
1945         for (p = packed_git; p; p = p->next) {
1946                 for (i = 0; i < revs->num_ignore_packed; i++) {
1947                         if (matches_pack_name(p, revs->ignore_packed[i]))
1948                                 break;
1949                 }
1950                 if (revs->num_ignore_packed <= i)
1951                         continue;
1952
1953                 if (open_pack_index(p))
1954                         die("cannot open pack index");
1955
1956                 for (i = 0; i < p->num_objects; i++) {
1957                         sha1 = nth_packed_object_sha1(p, i);
1958                         if (!locate_object_entry(sha1))
1959                                 if (force_object_loose(sha1, p->mtime))
1960                                         die("unable to force loose object");
1961                 }
1962         }
1963 }
1964
1965 static void get_object_list(int ac, const char **av)
1966 {
1967         struct rev_info revs;
1968         char line[1000];
1969         int flags = 0;
1970
1971         init_revisions(&revs, NULL);
1972         save_commit_buffer = 0;
1973         setup_revisions(ac, av, &revs, NULL);
1974
1975         while (fgets(line, sizeof(line), stdin) != NULL) {
1976                 int len = strlen(line);
1977                 if (len && line[len - 1] == '\n')
1978                         line[--len] = 0;
1979                 if (!len)
1980                         break;
1981                 if (*line == '-') {
1982                         if (!strcmp(line, "--not")) {
1983                                 flags ^= UNINTERESTING;
1984                                 continue;
1985                         }
1986                         die("not a rev '%s'", line);
1987                 }
1988                 if (handle_revision_arg(line, &revs, flags, 1))
1989                         die("bad revision '%s'", line);
1990         }
1991
1992         if (prepare_revision_walk(&revs))
1993                 die("revision walk setup failed");
1994         mark_edges_uninteresting(revs.commits, &revs, show_edge);
1995         traverse_commit_list(&revs, show_commit, show_object);
1996
1997         if (keep_unreachable)
1998                 add_objects_in_unpacked_packs(&revs);
1999         if (unpack_unreachable)
2000                 loosen_unused_packed_objects(&revs);
2001 }
2002
2003 static int adjust_perm(const char *path, mode_t mode)
2004 {
2005         if (chmod(path, mode))
2006                 return -1;
2007         return adjust_shared_perm(path);
2008 }
2009
2010 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2011 {
2012         int use_internal_rev_list = 0;
2013         int thin = 0;
2014         uint32_t i;
2015         const char **rp_av;
2016         int rp_ac_alloc = 64;
2017         int rp_ac;
2018
2019         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2020
2021         rp_av[0] = "pack-objects";
2022         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2023         rp_ac = 2;
2024
2025         git_config(git_pack_config, NULL);
2026         if (!pack_compression_seen && core_compression_seen)
2027                 pack_compression_level = core_compression_level;
2028
2029         progress = isatty(2);
2030         for (i = 1; i < argc; i++) {
2031                 const char *arg = argv[i];
2032
2033                 if (*arg != '-')
2034                         break;
2035
2036                 if (!strcmp("--non-empty", arg)) {
2037                         non_empty = 1;
2038                         continue;
2039                 }
2040                 if (!strcmp("--local", arg)) {
2041                         local = 1;
2042                         continue;
2043                 }
2044                 if (!strcmp("--incremental", arg)) {
2045                         incremental = 1;
2046                         continue;
2047                 }
2048                 if (!strcmp("--honor-pack-keep", arg)) {
2049                         ignore_packed_keep = 1;
2050                         continue;
2051                 }
2052                 if (!prefixcmp(arg, "--compression=")) {
2053                         char *end;
2054                         int level = strtoul(arg+14, &end, 0);
2055                         if (!arg[14] || *end)
2056                                 usage(pack_usage);
2057                         if (level == -1)
2058                                 level = Z_DEFAULT_COMPRESSION;
2059                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2060                                 die("bad pack compression level %d", level);
2061                         pack_compression_level = level;
2062                         continue;
2063                 }
2064                 if (!prefixcmp(arg, "--max-pack-size=")) {
2065                         char *end;
2066                         pack_size_limit_cfg = 0;
2067                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2068                         if (!arg[16] || *end)
2069                                 usage(pack_usage);
2070                         continue;
2071                 }
2072                 if (!prefixcmp(arg, "--window=")) {
2073                         char *end;
2074                         window = strtoul(arg+9, &end, 0);
2075                         if (!arg[9] || *end)
2076                                 usage(pack_usage);
2077                         continue;
2078                 }
2079                 if (!prefixcmp(arg, "--window-memory=")) {
2080                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2081                                 usage(pack_usage);
2082                         continue;
2083                 }
2084                 if (!prefixcmp(arg, "--threads=")) {
2085                         char *end;
2086                         delta_search_threads = strtoul(arg+10, &end, 0);
2087                         if (!arg[10] || *end || delta_search_threads < 0)
2088                                 usage(pack_usage);
2089 #ifndef THREADED_DELTA_SEARCH
2090                         if (delta_search_threads != 1)
2091                                 warning("no threads support, "
2092                                         "ignoring %s", arg);
2093 #endif
2094                         continue;
2095                 }
2096                 if (!prefixcmp(arg, "--depth=")) {
2097                         char *end;
2098                         depth = strtoul(arg+8, &end, 0);
2099                         if (!arg[8] || *end)
2100                                 usage(pack_usage);
2101                         continue;
2102                 }
2103                 if (!strcmp("--progress", arg)) {
2104                         progress = 1;
2105                         continue;
2106                 }
2107                 if (!strcmp("--all-progress", arg)) {
2108                         progress = 2;
2109                         continue;
2110                 }
2111                 if (!strcmp("-q", arg)) {
2112                         progress = 0;
2113                         continue;
2114                 }
2115                 if (!strcmp("--no-reuse-delta", arg)) {
2116                         reuse_delta = 0;
2117                         continue;
2118                 }
2119                 if (!strcmp("--no-reuse-object", arg)) {
2120                         reuse_object = reuse_delta = 0;
2121                         continue;
2122                 }
2123                 if (!strcmp("--delta-base-offset", arg)) {
2124                         allow_ofs_delta = 1;
2125                         continue;
2126                 }
2127                 if (!strcmp("--stdout", arg)) {
2128                         pack_to_stdout = 1;
2129                         continue;
2130                 }
2131                 if (!strcmp("--revs", arg)) {
2132                         use_internal_rev_list = 1;
2133                         continue;
2134                 }
2135                 if (!strcmp("--keep-unreachable", arg)) {
2136                         keep_unreachable = 1;
2137                         continue;
2138                 }
2139                 if (!strcmp("--unpack-unreachable", arg)) {
2140                         unpack_unreachable = 1;
2141                         continue;
2142                 }
2143                 if (!strcmp("--include-tag", arg)) {
2144                         include_tag = 1;
2145                         continue;
2146                 }
2147                 if (!strcmp("--unpacked", arg) ||
2148                     !prefixcmp(arg, "--unpacked=") ||
2149                     !strcmp("--reflog", arg) ||
2150                     !strcmp("--all", arg)) {
2151                         use_internal_rev_list = 1;
2152                         if (rp_ac >= rp_ac_alloc - 1) {
2153                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2154                                 rp_av = xrealloc(rp_av,
2155                                                  rp_ac_alloc * sizeof(*rp_av));
2156                         }
2157                         rp_av[rp_ac++] = arg;
2158                         continue;
2159                 }
2160                 if (!strcmp("--thin", arg)) {
2161                         use_internal_rev_list = 1;
2162                         thin = 1;
2163                         rp_av[1] = "--objects-edge";
2164                         continue;
2165                 }
2166                 if (!prefixcmp(arg, "--index-version=")) {
2167                         char *c;
2168                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2169                         if (pack_idx_default_version > 2)
2170                                 die("bad %s", arg);
2171                         if (*c == ',')
2172                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2173                         if (*c || pack_idx_off32_limit & 0x80000000)
2174                                 die("bad %s", arg);
2175                         continue;
2176                 }
2177                 usage(pack_usage);
2178         }
2179
2180         /* Traditionally "pack-objects [options] base extra" failed;
2181          * we would however want to take refs parameter that would
2182          * have been given to upstream rev-list ourselves, which means
2183          * we somehow want to say what the base name is.  So the
2184          * syntax would be:
2185          *
2186          * pack-objects [options] base <refs...>
2187          *
2188          * in other words, we would treat the first non-option as the
2189          * base_name and send everything else to the internal revision
2190          * walker.
2191          */
2192
2193         if (!pack_to_stdout)
2194                 base_name = argv[i++];
2195
2196         if (pack_to_stdout != !base_name)
2197                 usage(pack_usage);
2198
2199         if (!pack_to_stdout && !pack_size_limit)
2200                 pack_size_limit = pack_size_limit_cfg;
2201
2202         if (pack_to_stdout && pack_size_limit)
2203                 die("--max-pack-size cannot be used to build a pack for transfer.");
2204
2205         if (!pack_to_stdout && thin)
2206                 die("--thin cannot be used to build an indexable pack.");
2207
2208         if (keep_unreachable && unpack_unreachable)
2209                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2210
2211 #ifdef THREADED_DELTA_SEARCH
2212         if (!delta_search_threads)      /* --threads=0 means autodetect */
2213                 delta_search_threads = online_cpus();
2214 #endif
2215
2216         prepare_packed_git();
2217
2218         if (progress)
2219                 progress_state = start_progress("Counting objects", 0);
2220         if (!use_internal_rev_list)
2221                 read_object_list_from_stdin();
2222         else {
2223                 rp_av[rp_ac] = NULL;
2224                 get_object_list(rp_ac, rp_av);
2225         }
2226         if (include_tag && nr_result)
2227                 for_each_ref(add_ref_tag, NULL);
2228         stop_progress(&progress_state);
2229
2230         if (non_empty && !nr_result)
2231                 return 0;
2232         if (nr_result)
2233                 prepare_pack(window, depth);
2234         write_pack_file();
2235         if (progress)
2236                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2237                         " reused %"PRIu32" (delta %"PRIu32")\n",
2238                         written, written_delta, reused, reused_delta);
2239         return 0;
2240 }