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 allow_ofs_delta;
  75 static const char *base_name;
  76 static int progress = 1;
  77 static int window = 10;
  78 static uint32_t pack_size_limit, pack_size_limit_cfg;
  79 static int depth = 50;
  80 static int delta_search_threads = 1;
  81 static int pack_to_stdout;
  82 static int num_preferred_base;
  83 static struct progress *progress_state;
  84 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  85 static int pack_compression_seen;
  86
  87 static unsigned long delta_cache_size = 0;
  88 static unsigned long max_delta_cache_size = 0;
  89 static unsigned long cache_max_small_delta_size = 1000;
  90
  91 static unsigned long window_memory_limit = 0;
  92
  93 /*
  94  * The object names in objects array are hashed with this hashtable,
  95  * to help looking up the entry by object name.
  96  * This hashtable is built after all the objects are seen.
  97  */
  98 static int *object_ix;
  99 static int object_ix_hashsz;
 100
 101 /*
 102  * stats
 103  */
 104 static uint32_t written, written_delta;
 105 static uint32_t reused, reused_delta;
 106
 107
 108 static void *get_delta(struct object_entry *entry)
 109 {
 110         unsigned long size, base_size, delta_size;
 111         void *buf, *base_buf, *delta_buf;
 112         enum object_type type;
 113
 114         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 115         if (!buf)
 116                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 117         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
 118         if (!base_buf)
 119                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 120         delta_buf = diff_delta(base_buf, base_size,
 121                                buf, size, &delta_size, 0);
 122         if (!delta_buf || delta_size != entry->delta_size)
 123                 die("delta size changed");
 124         free(buf);
 125         free(base_buf);
 126         return delta_buf;
 127 }
 128
 129 static unsigned long do_compress(void **pptr, unsigned long size)
 130 {
 131         z_stream stream;
 132         void *in, *out;
 133         unsigned long maxsize;
 134
 135         memset(&stream, 0, sizeof(stream));
 136         deflateInit(&stream, pack_compression_level);
 137         maxsize = deflateBound(&stream, size);
 138
 139         in = *pptr;
 140         out = xmalloc(maxsize);
 141         *pptr = out;
 142
 143         stream.next_in = in;
 144         stream.avail_in = size;
 145         stream.next_out = out;
 146         stream.avail_out = maxsize;
 147         while (deflate(&stream, Z_FINISH) == Z_OK)
 148                 ; /* nothing */
 149         deflateEnd(&stream);
 150
 151         free(in);
 152         return stream.total_out;
 153 }
 154
 155 /*
 156  * The per-object header is a pretty dense thing, which is
 157  *  - first byte: low four bits are "size", then three bits of "type",
 158  *    and the high bit is "size continues".
 159  *  - each byte afterwards: low seven bits are size continuation,
 160  *    with the high bit being "size continues"
 161  */
 162 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 163 {
 164         int n = 1;
 165         unsigned char c;
 166
 167         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 168                 die("bad type %d", type);
 169
 170         c = (type << 4) | (size & 15);
 171         size >>= 4;
 172         while (size) {
 173                 *hdr++ = c | 0x80;
 174                 c = size & 0x7f;
 175                 size >>= 7;
 176                 n++;
 177         }
 178         *hdr = c;
 179         return n;
 180 }
 181
 182 /*
 183  * we are going to reuse the existing object data as is.  make
 184  * sure it is not corrupt.
 185  */
 186 static int check_pack_inflate(struct packed_git *p,
 187                 struct pack_window **w_curs,
 188                 off_t offset,
 189                 off_t len,
 190                 unsigned long expect)
 191 {
 192         z_stream stream;
 193         unsigned char fakebuf[4096], *in;
 194         int st;
 195
 196         memset(&stream, 0, sizeof(stream));
 197         inflateInit(&stream);
 198         do {
 199                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 200                 stream.next_in = in;
 201                 stream.next_out = fakebuf;
 202                 stream.avail_out = sizeof(fakebuf);
 203                 st = inflate(&stream, Z_FINISH);
 204                 offset += stream.next_in - in;
 205         } while (st == Z_OK || st == Z_BUF_ERROR);
 206         inflateEnd(&stream);
 207         return (st == Z_STREAM_END &&
 208                 stream.total_out == expect &&
 209                 stream.total_in == len) ? 0 : -1;
 210 }
 211
 212 static void copy_pack_data(struct sha1file *f,
 213                 struct packed_git *p,
 214                 struct pack_window **w_curs,
 215                 off_t offset,
 216                 off_t len)
 217 {
 218         unsigned char *in;
 219         unsigned int avail;
 220
 221         while (len) {
 222                 in = use_pack(p, w_curs, offset, &avail);
 223                 if (avail > len)
 224                         avail = (unsigned int)len;
 225                 sha1write(f, in, avail);
 226                 offset += avail;
 227                 len -= avail;
 228         }
 229 }
 230
 231 static unsigned long write_object(struct sha1file *f,
 232                                   struct object_entry *entry,
 233                                   off_t write_offset)
 234 {
 235         unsigned long size, limit, datalen;
 236         void *buf;
 237         unsigned char header[10], dheader[10];
 238         unsigned hdrlen;
 239         enum object_type type;
 240         int usable_delta, to_reuse;
 241
 242         if (!pack_to_stdout)
 243                 crc32_begin(f);
 244
 245         type = entry->type;
 246
 247         /* write limit if limited packsize and not first object */
 248         limit = pack_size_limit && nr_written ?
 249                         pack_size_limit - write_offset : 0;
 250
 251         if (!entry->delta)
 252                 usable_delta = 0;       /* no delta */
 253         else if (!pack_size_limit)
 254                usable_delta = 1;        /* unlimited packfile */
 255         else if (entry->delta->idx.offset == (off_t)-1)
 256                 usable_delta = 0;       /* base was written to another pack */
 257         else if (entry->delta->idx.offset)
 258                 usable_delta = 1;       /* base already exists in this pack */
 259         else
 260                 usable_delta = 0;       /* base could end up in another pack */
 261
 262         if (!reuse_object)
 263                 to_reuse = 0;   /* explicit */
 264         else if (!entry->in_pack)
 265                 to_reuse = 0;   /* can't reuse what we don't have */
 266         else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
 267                                 /* check_object() decided it for us ... */
 268                 to_reuse = usable_delta;
 269                                 /* ... but pack split may override that */
 270         else if (type != entry->in_pack_type)
 271                 to_reuse = 0;   /* pack has delta which is unusable */
 272         else if (entry->delta)
 273                 to_reuse = 0;   /* we want to pack afresh */
 274         else
 275                 to_reuse = 1;   /* we have it in-pack undeltified,
 276                                  * and we do not need to deltify it.
 277                                  */
 278
 279         if (!to_reuse) {
 280                 no_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                 hdrlen = encode_header(type, entry->size, header);
 366
 367                 offset = entry->in_pack_offset;
 368                 revidx = find_pack_revindex(p, offset);
 369                 datalen = revidx[1].offset - offset;
 370                 if (!pack_to_stdout && p->index_version > 1 &&
 371                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
 372                         error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 373                         unuse_pack(&w_curs);
 374                         goto no_reuse;
 375                 }
 376
 377                 offset += entry->in_pack_header_size;
 378                 datalen -= entry->in_pack_header_size;
 379                 if (!pack_to_stdout && p->index_version == 1 &&
 380                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
 381                         error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 382                         unuse_pack(&w_curs);
 383                         goto no_reuse;
 384                 }
 385
 386                 if (type == OBJ_OFS_DELTA) {
 387                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 388                         unsigned pos = sizeof(dheader) - 1;
 389                         dheader[pos] = ofs & 127;
 390                         while (ofs >>= 7)
 391                                 dheader[--pos] = 128 | (--ofs & 127);
 392                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 393                                 unuse_pack(&w_curs);
 394                                 return 0;
 395                         }
 396                         sha1write(f, header, hdrlen);
 397                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 398                         hdrlen += sizeof(dheader) - pos;
 399                         reused_delta++;
 400                 } else if (type == OBJ_REF_DELTA) {
 401                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 402                                 unuse_pack(&w_curs);
 403                                 return 0;
 404                         }
 405                         sha1write(f, header, hdrlen);
 406                         sha1write(f, entry->delta->idx.sha1, 20);
 407                         hdrlen += 20;
 408                         reused_delta++;
 409                 } else {
 410                         if (limit && hdrlen + datalen + 20 >= limit) {
 411                                 unuse_pack(&w_curs);
 412                                 return 0;
 413                         }
 414                         sha1write(f, header, hdrlen);
 415                 }
 416                 copy_pack_data(f, p, &w_curs, offset, datalen);
 417                 unuse_pack(&w_curs);
 418                 reused++;
 419         }
 420         if (usable_delta)
 421                 written_delta++;
 422         written++;
 423         if (!pack_to_stdout)
 424                 entry->idx.crc32 = crc32_end(f);
 425         return hdrlen + datalen;
 426 }
 427
 428 static int write_one(struct sha1file *f,
 429                                struct object_entry *e,
 430                                off_t *offset)
 431 {
 432         unsigned long size;
 433
 434         /* offset is non zero if object is written already. */
 435         if (e->idx.offset || e->preferred_base)
 436                 return 1;
 437
 438         /* if we are deltified, write out base object first. */
 439         if (e->delta && !write_one(f, e->delta, offset))
 440                 return 0;
 441
 442         e->idx.offset = *offset;
 443         size = write_object(f, e, *offset);
 444         if (!size) {
 445                 e->idx.offset = 0;
 446                 return 0;
 447         }
 448         written_list[nr_written++] = &e->idx;
 449
 450         /* make sure off_t is sufficiently large not to wrap */
 451         if (*offset > *offset + size)
 452                 die("pack too large for current definition of off_t");
 453         *offset += size;
 454         return 1;
 455 }
 456
 457 /* forward declaration for write_pack_file */
 458 static int adjust_perm(const char *path, mode_t mode);
 459
 460 static void write_pack_file(void)
 461 {
 462         uint32_t i = 0, j;
 463         struct sha1file *f;
 464         off_t offset;
 465         struct pack_header hdr;
 466         uint32_t nr_remaining = nr_result;
 467         time_t last_mtime = 0;
 468
 469         if (progress > pack_to_stdout)
 470                 progress_state = start_progress("Writing objects", nr_result);
 471         written_list = xmalloc(nr_objects * sizeof(*written_list));
 472
 473         do {
 474                 unsigned char sha1[20];
 475                 char *pack_tmp_name = NULL;
 476
 477                 if (pack_to_stdout) {
 478                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 479                 } else {
 480                         char tmpname[PATH_MAX];
 481                         int fd;
 482                         snprintf(tmpname, sizeof(tmpname),
 483                                  "%s/pack/tmp_pack_XXXXXX", get_object_directory());
 484                         fd = xmkstemp(tmpname);
 485                         pack_tmp_name = xstrdup(tmpname);
 486                         f = sha1fd(fd, pack_tmp_name);
 487                 }
 488
 489                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
 490                 hdr.hdr_version = htonl(PACK_VERSION);
 491                 hdr.hdr_entries = htonl(nr_remaining);
 492                 sha1write(f, &hdr, sizeof(hdr));
 493                 offset = sizeof(hdr);
 494                 nr_written = 0;
 495                 for (; i < nr_objects; i++) {
 496                         if (!write_one(f, objects + i, &offset))
 497                                 break;
 498                         display_progress(progress_state, written);
 499                 }
 500
 501                 /*
 502                  * Did we write the wrong # entries in the header?
 503                  * If so, rewrite it like in fast-import
 504                  */
 505                 if (pack_to_stdout) {
 506                         sha1close(f, sha1, CSUM_CLOSE);
 507                 } else if (nr_written == nr_remaining) {
 508                         sha1close(f, sha1, CSUM_FSYNC);
 509                 } else {
 510                         int fd = sha1close(f, sha1, 0);
 511                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
 512                                                  nr_written, sha1, offset);
 513                         close(fd);
 514                 }
 515
 516                 if (!pack_to_stdout) {
 517                         mode_t mode = umask(0);
 518                         struct stat st;
 519                         char *idx_tmp_name, tmpname[PATH_MAX];
 520
 521                         umask(mode);
 522                         mode = 0444 & ~mode;
 523
 524                         idx_tmp_name = write_idx_file(NULL, written_list,
 525                                                       nr_written, sha1);
 526
 527                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 528                                  base_name, sha1_to_hex(sha1));
 529                         if (adjust_perm(pack_tmp_name, mode))
 530                                 die("unable to make temporary pack file readable: %s",
 531                                     strerror(errno));
 532                         if (rename(pack_tmp_name, tmpname))
 533                                 die("unable to rename temporary pack file: %s",
 534                                     strerror(errno));
 535
 536                         /*
 537                          * Packs are runtime accessed in their mtime
 538                          * order since newer packs are more likely to contain
 539                          * younger objects.  So if we are creating multiple
 540                          * packs then we should modify the mtime of later ones
 541                          * to preserve this property.
 542                          */
 543                         if (stat(tmpname, &st) < 0) {
 544                                 warning("failed to stat %s: %s",
 545                                         tmpname, strerror(errno));
 546                         } else if (!last_mtime) {
 547                                 last_mtime = st.st_mtime;
 548                         } else {
 549                                 struct utimbuf utb;
 550                                 utb.actime = st.st_atime;
 551                                 utb.modtime = --last_mtime;
 552                                 if (utime(tmpname, &utb) < 0)
 553                                         warning("failed utime() on %s: %s",
 554                                                 tmpname, strerror(errno));
 555                         }
 556
 557                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 558                                  base_name, sha1_to_hex(sha1));
 559                         if (adjust_perm(idx_tmp_name, mode))
 560                                 die("unable to make temporary index file readable: %s",
 561                                     strerror(errno));
 562                         if (rename(idx_tmp_name, tmpname))
 563                                 die("unable to rename temporary index file: %s",
 564                                     strerror(errno));
 565
 566                         free(idx_tmp_name);
 567                         free(pack_tmp_name);
 568                         puts(sha1_to_hex(sha1));
 569                 }
 570
 571                 /* mark written objects as written to previous pack */
 572                 for (j = 0; j < nr_written; j++) {
 573                         written_list[j]->offset = (off_t)-1;
 574                 }
 575                 nr_remaining -= nr_written;
 576         } while (nr_remaining && i < nr_objects);
 577
 578         free(written_list);
 579         stop_progress(&progress_state);
 580         if (written != nr_result)
 581                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
 582                         written, nr_result);
 583         /*
 584          * We have scanned through [0 ... i).  Since we have written
 585          * the correct number of objects,  the remaining [i ... nr_objects)
 586          * items must be either already written (due to out-of-order delta base)
 587          * or a preferred base.  Count those which are neither and complain if any.
 588          */
 589         for (j = 0; i < nr_objects; i++) {
 590                 struct object_entry *e = objects + i;
 591                 j += !e->idx.offset && !e->preferred_base;
 592         }
 593         if (j)
 594                 die("wrote %"PRIu32" objects as expected but %"PRIu32
 595                         " unwritten", written, j);
 596 }
 597
 598 static int locate_object_entry_hash(const unsigned char *sha1)
 599 {
 600         int i;
 601         unsigned int ui;
 602         memcpy(&ui, sha1, sizeof(unsigned int));
 603         i = ui % object_ix_hashsz;
 604         while (0 < object_ix[i]) {
 605                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 606                         return i;
 607                 if (++i == object_ix_hashsz)
 608                         i = 0;
 609         }
 610         return -1 - i;
 611 }
 612
 613 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 614 {
 615         int i;
 616
 617         if (!object_ix_hashsz)
 618                 return NULL;
 619
 620         i = locate_object_entry_hash(sha1);
 621         if (0 <= i)
 622                 return &objects[object_ix[i]-1];
 623         return NULL;
 624 }
 625
 626 static void rehash_objects(void)
 627 {
 628         uint32_t i;
 629         struct object_entry *oe;
 630
 631         object_ix_hashsz = nr_objects * 3;
 632         if (object_ix_hashsz < 1024)
 633                 object_ix_hashsz = 1024;
 634         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 635         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 636         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 637                 int ix = locate_object_entry_hash(oe->idx.sha1);
 638                 if (0 <= ix)
 639                         continue;
 640                 ix = -1 - ix;
 641                 object_ix[ix] = i + 1;
 642         }
 643 }
 644
 645 static unsigned name_hash(const char *name)
 646 {
 647         unsigned char c;
 648         unsigned hash = 0;
 649
 650         if (!name)
 651                 return 0;
 652
 653         /*
 654          * This effectively just creates a sortable number from the
 655          * last sixteen non-whitespace characters. Last characters
 656          * count "most", so things that end in ".c" sort together.
 657          */
 658         while ((c = *name++) != 0) {
 659                 if (isspace(c))
 660                         continue;
 661                 hash = (hash >> 2) + (c << 24);
 662         }
 663         return hash;
 664 }
 665
 666 static void setup_delta_attr_check(struct git_attr_check *check)
 667 {
 668         static struct git_attr *attr_delta;
 669
 670         if (!attr_delta)
 671                 attr_delta = git_attr("delta", 5);
 672
 673         check[0].attr = attr_delta;
 674 }
 675
 676 static int no_try_delta(const char *path)
 677 {
 678         struct git_attr_check check[1];
 679
 680         setup_delta_attr_check(check);
 681         if (git_checkattr(path, ARRAY_SIZE(check), check))
 682                 return 0;
 683         if (ATTR_FALSE(check->value))
 684                 return 1;
 685         return 0;
 686 }
 687
 688 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 689                             const char *name, int exclude)
 690 {
 691         struct object_entry *entry;
 692         struct packed_git *p, *found_pack = NULL;
 693         off_t found_offset = 0;
 694         int ix;
 695         unsigned hash = name_hash(name);
 696
 697         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 698         if (ix >= 0) {
 699                 if (exclude) {
 700                         entry = objects + object_ix[ix] - 1;
 701                         if (!entry->preferred_base)
 702                                 nr_result--;
 703                         entry->preferred_base = 1;
 704                 }
 705                 return 0;
 706         }
 707
 708         for (p = packed_git; p; p = p->next) {
 709                 off_t offset = find_pack_entry_one(sha1, p);
 710                 if (offset) {
 711                         if (!found_pack) {
 712                                 found_offset = offset;
 713                                 found_pack = p;
 714                         }
 715                         if (exclude)
 716                                 break;
 717                         if (incremental)
 718                                 return 0;
 719                         if (local && !p->pack_local)
 720                                 return 0;
 721                 }
 722         }
 723
 724         if (nr_objects >= nr_alloc) {
 725                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 726                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 727         }
 728
 729         entry = objects + nr_objects++;
 730         memset(entry, 0, sizeof(*entry));
 731         hashcpy(entry->idx.sha1, sha1);
 732         entry->hash = hash;
 733         if (type)
 734                 entry->type = type;
 735         if (exclude)
 736                 entry->preferred_base = 1;
 737         else
 738                 nr_result++;
 739         if (found_pack) {
 740                 entry->in_pack = found_pack;
 741                 entry->in_pack_offset = found_offset;
 742         }
 743
 744         if (object_ix_hashsz * 3 <= nr_objects * 4)
 745                 rehash_objects();
 746         else
 747                 object_ix[-1 - ix] = nr_objects;
 748
 749         display_progress(progress_state, nr_objects);
 750
 751         if (name && no_try_delta(name))
 752                 entry->no_try_delta = 1;
 753
 754         return 1;
 755 }
 756
 757 struct pbase_tree_cache {
 758         unsigned char sha1[20];
 759         int ref;
 760         int temporary;
 761         void *tree_data;
 762         unsigned long tree_size;
 763 };
 764
 765 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 766 static int pbase_tree_cache_ix(const unsigned char *sha1)
 767 {
 768         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 769 }
 770 static int pbase_tree_cache_ix_incr(int ix)
 771 {
 772         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 773 }
 774
 775 static struct pbase_tree {
 776         struct pbase_tree *next;
 777         /* This is a phony "cache" entry; we are not
 778          * going to evict it nor find it through _get()
 779          * mechanism -- this is for the toplevel node that
 780          * would almost always change with any commit.
 781          */
 782         struct pbase_tree_cache pcache;
 783 } *pbase_tree;
 784
 785 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 786 {
 787         struct pbase_tree_cache *ent, *nent;
 788         void *data;
 789         unsigned long size;
 790         enum object_type type;
 791         int neigh;
 792         int my_ix = pbase_tree_cache_ix(sha1);
 793         int available_ix = -1;
 794
 795         /* pbase-tree-cache acts as a limited hashtable.
 796          * your object will be found at your index or within a few
 797          * slots after that slot if it is cached.
 798          */
 799         for (neigh = 0; neigh < 8; neigh++) {
 800                 ent = pbase_tree_cache[my_ix];
 801                 if (ent && !hashcmp(ent->sha1, sha1)) {
 802                         ent->ref++;
 803                         return ent;
 804                 }
 805                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 806                          ((0 <= available_ix) &&
 807                           (!ent && pbase_tree_cache[available_ix])))
 808                         available_ix = my_ix;
 809                 if (!ent)
 810                         break;
 811                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 812         }
 813
 814         /* Did not find one.  Either we got a bogus request or
 815          * we need to read and perhaps cache.
 816          */
 817         data = read_sha1_file(sha1, &type, &size);
 818         if (!data)
 819                 return NULL;
 820         if (type != OBJ_TREE) {
 821                 free(data);
 822                 return NULL;
 823         }
 824
 825         /* We need to either cache or return a throwaway copy */
 826
 827         if (available_ix < 0)
 828                 ent = NULL;
 829         else {
 830                 ent = pbase_tree_cache[available_ix];
 831                 my_ix = available_ix;
 832         }
 833
 834         if (!ent) {
 835                 nent = xmalloc(sizeof(*nent));
 836                 nent->temporary = (available_ix < 0);
 837         }
 838         else {
 839                 /* evict and reuse */
 840                 free(ent->tree_data);
 841                 nent = ent;
 842         }
 843         hashcpy(nent->sha1, sha1);
 844         nent->tree_data = data;
 845         nent->tree_size = size;
 846         nent->ref = 1;
 847         if (!nent->temporary)
 848                 pbase_tree_cache[my_ix] = nent;
 849         return nent;
 850 }
 851
 852 static void pbase_tree_put(struct pbase_tree_cache *cache)
 853 {
 854         if (!cache->temporary) {
 855                 cache->ref--;
 856                 return;
 857         }
 858         free(cache->tree_data);
 859         free(cache);
 860 }
 861
 862 static int name_cmp_len(const char *name)
 863 {
 864         int i;
 865         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 866                 ;
 867         return i;
 868 }
 869
 870 static void add_pbase_object(struct tree_desc *tree,
 871                              const char *name,
 872                              int cmplen,
 873                              const char *fullname)
 874 {
 875         struct name_entry entry;
 876         int cmp;
 877
 878         while (tree_entry(tree,&entry)) {
 879                 if (S_ISGITLINK(entry.mode))
 880                         continue;
 881                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 882                       memcmp(name, entry.path, cmplen);
 883                 if (cmp > 0)
 884                         continue;
 885                 if (cmp < 0)
 886                         return;
 887                 if (name[cmplen] != '/') {
 888                         add_object_entry(entry.sha1,
 889                                          object_type(entry.mode),
 890                                          fullname, 1);
 891                         return;
 892                 }
 893                 if (S_ISDIR(entry.mode)) {
 894                         struct tree_desc sub;
 895                         struct pbase_tree_cache *tree;
 896                         const char *down = name+cmplen+1;
 897                         int downlen = name_cmp_len(down);
 898
 899                         tree = pbase_tree_get(entry.sha1);
 900                         if (!tree)
 901                                 return;
 902                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
 903
 904                         add_pbase_object(&sub, down, downlen, fullname);
 905                         pbase_tree_put(tree);
 906                 }
 907         }
 908 }
 909
 910 static unsigned *done_pbase_paths;
 911 static int done_pbase_paths_num;
 912 static int done_pbase_paths_alloc;
 913 static int done_pbase_path_pos(unsigned hash)
 914 {
 915         int lo = 0;
 916         int hi = done_pbase_paths_num;
 917         while (lo < hi) {
 918                 int mi = (hi + lo) / 2;
 919                 if (done_pbase_paths[mi] == hash)
 920                         return mi;
 921                 if (done_pbase_paths[mi] < hash)
 922                         hi = mi;
 923                 else
 924                         lo = mi + 1;
 925         }
 926         return -lo-1;
 927 }
 928
 929 static int check_pbase_path(unsigned hash)
 930 {
 931         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 932         if (0 <= pos)
 933                 return 1;
 934         pos = -pos - 1;
 935         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 936                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 937                 done_pbase_paths = xrealloc(done_pbase_paths,
 938                                             done_pbase_paths_alloc *
 939                                             sizeof(unsigned));
 940         }
 941         done_pbase_paths_num++;
 942         if (pos < done_pbase_paths_num)
 943                 memmove(done_pbase_paths + pos + 1,
 944                         done_pbase_paths + pos,
 945                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 946         done_pbase_paths[pos] = hash;
 947         return 0;
 948 }
 949
 950 static void add_preferred_base_object(const char *name)
 951 {
 952         struct pbase_tree *it;
 953         int cmplen;
 954         unsigned hash = name_hash(name);
 955
 956         if (!num_preferred_base || check_pbase_path(hash))
 957                 return;
 958
 959         cmplen = name_cmp_len(name);
 960         for (it = pbase_tree; it; it = it->next) {
 961                 if (cmplen == 0) {
 962                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
 963                 }
 964                 else {
 965                         struct tree_desc tree;
 966                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
 967                         add_pbase_object(&tree, name, cmplen, name);
 968                 }
 969         }
 970 }
 971
 972 static void add_preferred_base(unsigned char *sha1)
 973 {
 974         struct pbase_tree *it;
 975         void *data;
 976         unsigned long size;
 977         unsigned char tree_sha1[20];
 978
 979         if (window <= num_preferred_base++)
 980                 return;
 981
 982         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 983         if (!data)
 984                 return;
 985
 986         for (it = pbase_tree; it; it = it->next) {
 987                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 988                         free(data);
 989                         return;
 990                 }
 991         }
 992
 993         it = xcalloc(1, sizeof(*it));
 994         it->next = pbase_tree;
 995         pbase_tree = it;
 996
 997         hashcpy(it->pcache.sha1, tree_sha1);
 998         it->pcache.tree_data = data;
 999         it->pcache.tree_size = size;
1000 }
1001
1002 static void check_object(struct object_entry *entry)
1003 {
1004         if (entry->in_pack) {
1005                 struct packed_git *p = entry->in_pack;
1006                 struct pack_window *w_curs = NULL;
1007                 const unsigned char *base_ref = NULL;
1008                 struct object_entry *base_entry;
1009                 unsigned long used, used_0;
1010                 unsigned int avail;
1011                 off_t ofs;
1012                 unsigned char *buf, c;
1013
1014                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1015
1016                 /*
1017                  * We want in_pack_type even if we do not reuse delta
1018                  * since non-delta representations could still be reused.
1019                  */
1020                 used = unpack_object_header_buffer(buf, avail,
1021                                                    &entry->in_pack_type,
1022                                                    &entry->size);
1023                 if (used == 0)
1024                         goto give_up;
1025
1026                 /*
1027                  * Determine if this is a delta and if so whether we can
1028                  * reuse it or not.  Otherwise let's find out as cheaply as
1029                  * possible what the actual type and size for this object is.
1030                  */
1031                 switch (entry->in_pack_type) {
1032                 default:
1033                         /* Not a delta hence we've already got all we need. */
1034                         entry->type = entry->in_pack_type;
1035                         entry->in_pack_header_size = used;
1036                         if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1037                                 goto give_up;
1038                         unuse_pack(&w_curs);
1039                         return;
1040                 case OBJ_REF_DELTA:
1041                         if (reuse_delta && !entry->preferred_base)
1042                                 base_ref = use_pack(p, &w_curs,
1043                                                 entry->in_pack_offset + used, NULL);
1044                         entry->in_pack_header_size = used + 20;
1045                         break;
1046                 case OBJ_OFS_DELTA:
1047                         buf = use_pack(p, &w_curs,
1048                                        entry->in_pack_offset + used, NULL);
1049                         used_0 = 0;
1050                         c = buf[used_0++];
1051                         ofs = c & 127;
1052                         while (c & 128) {
1053                                 ofs += 1;
1054                                 if (!ofs || MSB(ofs, 7)) {
1055                                         error("delta base offset overflow in pack for %s",
1056                                               sha1_to_hex(entry->idx.sha1));
1057                                         goto give_up;
1058                                 }
1059                                 c = buf[used_0++];
1060                                 ofs = (ofs << 7) + (c & 127);
1061                         }
1062                         ofs = entry->in_pack_offset - ofs;
1063                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1064                                 error("delta base offset out of bound for %s",
1065                                       sha1_to_hex(entry->idx.sha1));
1066                                 goto give_up;
1067                         }
1068                         if (reuse_delta && !entry->preferred_base) {
1069                                 struct revindex_entry *revidx;
1070                                 revidx = find_pack_revindex(p, ofs);
1071                                 if (!revidx)
1072                                         goto give_up;
1073                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1074                         }
1075                         entry->in_pack_header_size = used + used_0;
1076                         break;
1077                 }
1078
1079                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1080                         /*
1081                          * If base_ref was set above that means we wish to
1082                          * reuse delta data, and we even found that base
1083                          * in the list of objects we want to pack. Goodie!
1084                          *
1085                          * Depth value does not matter - find_deltas() will
1086                          * never consider reused delta as the base object to
1087                          * deltify other objects against, in order to avoid
1088                          * circular deltas.
1089                          */
1090                         entry->type = entry->in_pack_type;
1091                         entry->delta = base_entry;
1092                         entry->delta_size = entry->size;
1093                         entry->delta_sibling = base_entry->delta_child;
1094                         base_entry->delta_child = entry;
1095                         unuse_pack(&w_curs);
1096                         return;
1097                 }
1098
1099                 if (entry->type) {
1100                         /*
1101                          * This must be a delta and we already know what the
1102                          * final object type is.  Let's extract the actual
1103                          * object size from the delta header.
1104                          */
1105                         entry->size = get_size_from_delta(p, &w_curs,
1106                                         entry->in_pack_offset + entry->in_pack_header_size);
1107                         if (entry->size == 0)
1108                                 goto give_up;
1109                         unuse_pack(&w_curs);
1110                         return;
1111                 }
1112
1113                 /*
1114                  * No choice but to fall back to the recursive delta walk
1115                  * with sha1_object_info() to find about the object type
1116                  * at this point...
1117                  */
1118                 give_up:
1119                 unuse_pack(&w_curs);
1120         }
1121
1122         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1123         /*
1124          * The error condition is checked in prepare_pack().  This is
1125          * to permit a missing preferred base object to be ignored
1126          * as a preferred base.  Doing so can result in a larger
1127          * pack file, but the transfer will still take place.
1128          */
1129 }
1130
1131 static int pack_offset_sort(const void *_a, const void *_b)
1132 {
1133         const struct object_entry *a = *(struct object_entry **)_a;
1134         const struct object_entry *b = *(struct object_entry **)_b;
1135
1136         /* avoid filesystem trashing with loose objects */
1137         if (!a->in_pack && !b->in_pack)
1138                 return hashcmp(a->idx.sha1, b->idx.sha1);
1139
1140         if (a->in_pack < b->in_pack)
1141                 return -1;
1142         if (a->in_pack > b->in_pack)
1143                 return 1;
1144         return a->in_pack_offset < b->in_pack_offset ? -1 :
1145                         (a->in_pack_offset > b->in_pack_offset);
1146 }
1147
1148 static void get_object_details(void)
1149 {
1150         uint32_t i;
1151         struct object_entry **sorted_by_offset;
1152
1153         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1154         for (i = 0; i < nr_objects; i++)
1155                 sorted_by_offset[i] = objects + i;
1156         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1157
1158         for (i = 0; i < nr_objects; i++)
1159                 check_object(sorted_by_offset[i]);
1160
1161         free(sorted_by_offset);
1162 }
1163
1164 /*
1165  * We search for deltas in a list sorted by type, by filename hash, and then
1166  * by size, so that we see progressively smaller and smaller files.
1167  * That's because we prefer deltas to be from the bigger file
1168  * to the smaller -- deletes are potentially cheaper, but perhaps
1169  * more importantly, the bigger file is likely the more recent
1170  * one.  The deepest deltas are therefore the oldest objects which are
1171  * less susceptible to be accessed often.
1172  */
1173 static int type_size_sort(const void *_a, const void *_b)
1174 {
1175         const struct object_entry *a = *(struct object_entry **)_a;
1176         const struct object_entry *b = *(struct object_entry **)_b;
1177
1178         if (a->type > b->type)
1179                 return -1;
1180         if (a->type < b->type)
1181                 return 1;
1182         if (a->hash > b->hash)
1183                 return -1;
1184         if (a->hash < b->hash)
1185                 return 1;
1186         if (a->preferred_base > b->preferred_base)
1187                 return -1;
1188         if (a->preferred_base < b->preferred_base)
1189                 return 1;
1190         if (a->size > b->size)
1191                 return -1;
1192         if (a->size < b->size)
1193                 return 1;
1194         return a < b ? -1 : (a > b);  /* newest first */
1195 }
1196
1197 struct unpacked {
1198         struct object_entry *entry;
1199         void *data;
1200         struct delta_index *index;
1201         unsigned depth;
1202 };
1203
1204 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1205                            unsigned long delta_size)
1206 {
1207         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1208                 return 0;
1209
1210         if (delta_size < cache_max_small_delta_size)
1211                 return 1;
1212
1213         /* cache delta, if objects are large enough compared to delta size */
1214         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1215                 return 1;
1216
1217         return 0;
1218 }
1219
1220 #ifdef THREADED_DELTA_SEARCH
1221
1222 static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1223 #define read_lock()             pthread_mutex_lock(&read_mutex)
1224 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1225
1226 static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1227 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1228 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1229
1230 static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1231 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1232 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1233
1234 #else
1235
1236 #define read_lock()             (void)0
1237 #define read_unlock()           (void)0
1238 #define cache_lock()            (void)0
1239 #define cache_unlock()          (void)0
1240 #define progress_lock()         (void)0
1241 #define progress_unlock()       (void)0
1242
1243 #endif
1244
1245 static int try_delta(struct unpacked *trg, struct unpacked *src,
1246                      unsigned max_depth, unsigned long *mem_usage)
1247 {
1248         struct object_entry *trg_entry = trg->entry;
1249         struct object_entry *src_entry = src->entry;
1250         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1251         unsigned ref_depth;
1252         enum object_type type;
1253         void *delta_buf;
1254
1255         /* Don't bother doing diffs between different types */
1256         if (trg_entry->type != src_entry->type)
1257                 return -1;
1258
1259         /*
1260          * We do not bother to try a delta that we discarded
1261          * on an earlier try, but only when reusing delta data.
1262          */
1263         if (reuse_delta && trg_entry->in_pack &&
1264             trg_entry->in_pack == src_entry->in_pack &&
1265             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1266             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1267                 return 0;
1268
1269         /* Let's not bust the allowed depth. */
1270         if (src->depth >= max_depth)
1271                 return 0;
1272
1273         /* Now some size filtering heuristics. */
1274         trg_size = trg_entry->size;
1275         if (!trg_entry->delta) {
1276                 max_size = trg_size/2 - 20;
1277                 ref_depth = 1;
1278         } else {
1279                 max_size = trg_entry->delta_size;
1280                 ref_depth = trg->depth;
1281         }
1282         max_size = max_size * (max_depth - src->depth) /
1283                                                 (max_depth - ref_depth + 1);
1284         if (max_size == 0)
1285                 return 0;
1286         src_size = src_entry->size;
1287         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1288         if (sizediff >= max_size)
1289                 return 0;
1290         if (trg_size < src_size / 32)
1291                 return 0;
1292
1293         /* Load data if not already done */
1294         if (!trg->data) {
1295                 read_lock();
1296                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1297                 read_unlock();
1298                 if (!trg->data)
1299                         die("object %s cannot be read",
1300                             sha1_to_hex(trg_entry->idx.sha1));
1301                 if (sz != trg_size)
1302                         die("object %s inconsistent object length (%lu vs %lu)",
1303                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1304                 *mem_usage += sz;
1305         }
1306         if (!src->data) {
1307                 read_lock();
1308                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1309                 read_unlock();
1310                 if (!src->data)
1311                         die("object %s cannot be read",
1312                             sha1_to_hex(src_entry->idx.sha1));
1313                 if (sz != src_size)
1314                         die("object %s inconsistent object length (%lu vs %lu)",
1315                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1316                 *mem_usage += sz;
1317         }
1318         if (!src->index) {
1319                 src->index = create_delta_index(src->data, src_size);
1320                 if (!src->index) {
1321                         static int warned = 0;
1322                         if (!warned++)
1323                                 warning("suboptimal pack - out of memory");
1324                         return 0;
1325                 }
1326                 *mem_usage += sizeof_delta_index(src->index);
1327         }
1328
1329         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1330         if (!delta_buf)
1331                 return 0;
1332
1333         if (trg_entry->delta) {
1334                 /* Prefer only shallower same-sized deltas. */
1335                 if (delta_size == trg_entry->delta_size &&
1336                     src->depth + 1 >= trg->depth) {
1337                         free(delta_buf);
1338                         return 0;
1339                 }
1340         }
1341
1342         /*
1343          * Handle memory allocation outside of the cache
1344          * accounting lock.  Compiler will optimize the strangeness
1345          * away when THREADED_DELTA_SEARCH is not defined.
1346          */
1347         free(trg_entry->delta_data);
1348         cache_lock();
1349         if (trg_entry->delta_data) {
1350                 delta_cache_size -= trg_entry->delta_size;
1351                 trg_entry->delta_data = NULL;
1352         }
1353         if (delta_cacheable(src_size, trg_size, delta_size)) {
1354                 delta_cache_size += delta_size;
1355                 cache_unlock();
1356                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1357         } else {
1358                 cache_unlock();
1359                 free(delta_buf);
1360         }
1361
1362         trg_entry->delta = src_entry;
1363         trg_entry->delta_size = delta_size;
1364         trg->depth = src->depth + 1;
1365
1366         return 1;
1367 }
1368
1369 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1370 {
1371         struct object_entry *child = me->delta_child;
1372         unsigned int m = n;
1373         while (child) {
1374                 unsigned int c = check_delta_limit(child, n + 1);
1375                 if (m < c)
1376                         m = c;
1377                 child = child->delta_sibling;
1378         }
1379         return m;
1380 }
1381
1382 static unsigned long free_unpacked(struct unpacked *n)
1383 {
1384         unsigned long freed_mem = sizeof_delta_index(n->index);
1385         free_delta_index(n->index);
1386         n->index = NULL;
1387         if (n->data) {
1388                 freed_mem += n->entry->size;
1389                 free(n->data);
1390                 n->data = NULL;
1391         }
1392         n->entry = NULL;
1393         n->depth = 0;
1394         return freed_mem;
1395 }
1396
1397 static void find_deltas(struct object_entry **list, unsigned *list_size,
1398                         int window, int depth, unsigned *processed)
1399 {
1400         uint32_t i, idx = 0, count = 0;
1401         struct unpacked *array;
1402         unsigned long mem_usage = 0;
1403
1404         array = xcalloc(window, sizeof(struct unpacked));
1405
1406         for (;;) {
1407                 struct object_entry *entry;
1408                 struct unpacked *n = array + idx;
1409                 int j, max_depth, best_base = -1;
1410
1411                 progress_lock();
1412                 if (!*list_size) {
1413                         progress_unlock();
1414                         break;
1415                 }
1416                 entry = *list++;
1417                 (*list_size)--;
1418                 if (!entry->preferred_base) {
1419                         (*processed)++;
1420                         display_progress(progress_state, *processed);
1421                 }
1422                 progress_unlock();
1423
1424                 mem_usage -= free_unpacked(n);
1425                 n->entry = entry;
1426
1427                 while (window_memory_limit &&
1428                        mem_usage > window_memory_limit &&
1429                        count > 1) {
1430                         uint32_t tail = (idx + window - count) % window;
1431                         mem_usage -= free_unpacked(array + tail);
1432                         count--;
1433                 }
1434
1435                 /* We do not compute delta to *create* objects we are not
1436                  * going to pack.
1437                  */
1438                 if (entry->preferred_base)
1439                         goto next;
1440
1441                 /*
1442                  * If the current object is at pack edge, take the depth the
1443                  * objects that depend on the current object into account
1444                  * otherwise they would become too deep.
1445                  */
1446                 max_depth = depth;
1447                 if (entry->delta_child) {
1448                         max_depth -= check_delta_limit(entry, 0);
1449                         if (max_depth <= 0)
1450                                 goto next;
1451                 }
1452
1453                 j = window;
1454                 while (--j > 0) {
1455                         int ret;
1456                         uint32_t other_idx = idx + j;
1457                         struct unpacked *m;
1458                         if (other_idx >= window)
1459                                 other_idx -= window;
1460                         m = array + other_idx;
1461                         if (!m->entry)
1462                                 break;
1463                         ret = try_delta(n, m, max_depth, &mem_usage);
1464                         if (ret < 0)
1465                                 break;
1466                         else if (ret > 0)
1467                                 best_base = other_idx;
1468                 }
1469
1470                 /*
1471                  * If we decided to cache the delta data, then it is best
1472                  * to compress it right away.  First because we have to do
1473                  * it anyway, and doing it here while we're threaded will
1474                  * save a lot of time in the non threaded write phase,
1475                  * as well as allow for caching more deltas within
1476                  * the same cache size limit.
1477                  * ...
1478                  * But only if not writing to stdout, since in that case
1479                  * the network is most likely throttling writes anyway,
1480                  * and therefore it is best to go to the write phase ASAP
1481                  * instead, as we can afford spending more time compressing
1482                  * between writes at that moment.
1483                  */
1484                 if (entry->delta_data && !pack_to_stdout) {
1485                         entry->z_delta_size = do_compress(&entry->delta_data,
1486                                                           entry->delta_size);
1487                         cache_lock();
1488                         delta_cache_size -= entry->delta_size;
1489                         delta_cache_size += entry->z_delta_size;
1490                         cache_unlock();
1491                 }
1492
1493                 /* if we made n a delta, and if n is already at max
1494                  * depth, leaving it in the window is pointless.  we
1495                  * should evict it first.
1496                  */
1497                 if (entry->delta && max_depth <= n->depth)
1498                         continue;
1499
1500                 /*
1501                  * Move the best delta base up in the window, after the
1502                  * currently deltified object, to keep it longer.  It will
1503                  * be the first base object to be attempted next.
1504                  */
1505                 if (entry->delta) {
1506                         struct unpacked swap = array[best_base];
1507                         int dist = (window + idx - best_base) % window;
1508                         int dst = best_base;
1509                         while (dist--) {
1510                                 int src = (dst + 1) % window;
1511                                 array[dst] = array[src];
1512                                 dst = src;
1513                         }
1514                         array[dst] = swap;
1515                 }
1516
1517                 next:
1518                 idx++;
1519                 if (count + 1 < window)
1520                         count++;
1521                 if (idx >= window)
1522                         idx = 0;
1523         }
1524
1525         for (i = 0; i < window; ++i) {
1526                 free_delta_index(array[i].index);
1527                 free(array[i].data);
1528         }
1529         free(array);
1530 }
1531
1532 #ifdef THREADED_DELTA_SEARCH
1533
1534 /*
1535  * The main thread waits on the condition that (at least) one of the workers
1536  * has stopped working (which is indicated in the .working member of
1537  * struct thread_params).
1538  * When a work thread has completed its work, it sets .working to 0 and
1539  * signals the main thread and waits on the condition that .data_ready
1540  * becomes 1.
1541  */
1542
1543 struct thread_params {
1544         pthread_t thread;
1545         struct object_entry **list;
1546         unsigned list_size;
1547         unsigned remaining;
1548         int window;
1549         int depth;
1550         int working;
1551         int data_ready;
1552         pthread_mutex_t mutex;
1553         pthread_cond_t cond;
1554         unsigned *processed;
1555 };
1556
1557 static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
1558
1559 static void *threaded_find_deltas(void *arg)
1560 {
1561         struct thread_params *me = arg;
1562
1563         while (me->remaining) {
1564                 find_deltas(me->list, &me->remaining,
1565                             me->window, me->depth, me->processed);
1566
1567                 progress_lock();
1568                 me->working = 0;
1569                 pthread_cond_signal(&progress_cond);
1570                 progress_unlock();
1571
1572                 /*
1573                  * We must not set ->data_ready before we wait on the
1574                  * condition because the main thread may have set it to 1
1575                  * before we get here. In order to be sure that new
1576                  * work is available if we see 1 in ->data_ready, it
1577                  * was initialized to 0 before this thread was spawned
1578                  * and we reset it to 0 right away.
1579                  */
1580                 pthread_mutex_lock(&me->mutex);
1581                 while (!me->data_ready)
1582                         pthread_cond_wait(&me->cond, &me->mutex);
1583                 me->data_ready = 0;
1584                 pthread_mutex_unlock(&me->mutex);
1585         }
1586         /* leave ->working 1 so that this doesn't get more work assigned */
1587         return NULL;
1588 }
1589
1590 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1591                            int window, int depth, unsigned *processed)
1592 {
1593         struct thread_params p[delta_search_threads];
1594         int i, ret, active_threads = 0;
1595
1596         if (delta_search_threads <= 1) {
1597                 find_deltas(list, &list_size, window, depth, processed);
1598                 return;
1599         }
1600
1601         /* Partition the work amongst work threads. */
1602         for (i = 0; i < delta_search_threads; i++) {
1603                 unsigned sub_size = list_size / (delta_search_threads - i);
1604
1605                 p[i].window = window;
1606                 p[i].depth = depth;
1607                 p[i].processed = processed;
1608                 p[i].working = 1;
1609                 p[i].data_ready = 0;
1610
1611                 /* try to split chunks on "path" boundaries */
1612                 while (sub_size && sub_size < list_size &&
1613                        list[sub_size]->hash &&
1614                        list[sub_size]->hash == list[sub_size-1]->hash)
1615                         sub_size++;
1616
1617                 p[i].list = list;
1618                 p[i].list_size = sub_size;
1619                 p[i].remaining = sub_size;
1620
1621                 list += sub_size;
1622                 list_size -= sub_size;
1623         }
1624
1625         /* Start work threads. */
1626         for (i = 0; i < delta_search_threads; i++) {
1627                 if (!p[i].list_size)
1628                         continue;
1629                 pthread_mutex_init(&p[i].mutex, NULL);
1630                 pthread_cond_init(&p[i].cond, NULL);
1631                 ret = pthread_create(&p[i].thread, NULL,
1632                                      threaded_find_deltas, &p[i]);
1633                 if (ret)
1634                         die("unable to create thread: %s", strerror(ret));
1635                 active_threads++;
1636         }
1637
1638         /*
1639          * Now let's wait for work completion.  Each time a thread is done
1640          * with its work, we steal half of the remaining work from the
1641          * thread with the largest number of unprocessed objects and give
1642          * it to that newly idle thread.  This ensure good load balancing
1643          * until the remaining object list segments are simply too short
1644          * to be worth splitting anymore.
1645          */
1646         while (active_threads) {
1647                 struct thread_params *target = NULL;
1648                 struct thread_params *victim = NULL;
1649                 unsigned sub_size = 0;
1650
1651                 progress_lock();
1652                 for (;;) {
1653                         for (i = 0; !target && i < delta_search_threads; i++)
1654                                 if (!p[i].working)
1655                                         target = &p[i];
1656                         if (target)
1657                                 break;
1658                         pthread_cond_wait(&progress_cond, &progress_mutex);
1659                 }
1660
1661                 for (i = 0; i < delta_search_threads; i++)
1662                         if (p[i].remaining > 2*window &&
1663                             (!victim || victim->remaining < p[i].remaining))
1664                                 victim = &p[i];
1665                 if (victim) {
1666                         sub_size = victim->remaining / 2;
1667                         list = victim->list + victim->list_size - sub_size;
1668                         while (sub_size && list[0]->hash &&
1669                                list[0]->hash == list[-1]->hash) {
1670                                 list++;
1671                                 sub_size--;
1672                         }
1673                         if (!sub_size) {
1674                                 /*
1675                                  * It is possible for some "paths" to have
1676                                  * so many objects that no hash boundary
1677                                  * might be found.  Let's just steal the
1678                                  * exact half in that case.
1679                                  */
1680                                 sub_size = victim->remaining / 2;
1681                                 list -= sub_size;
1682                         }
1683                         target->list = list;
1684                         victim->list_size -= sub_size;
1685                         victim->remaining -= sub_size;
1686                 }
1687                 target->list_size = sub_size;
1688                 target->remaining = sub_size;
1689                 target->working = 1;
1690                 progress_unlock();
1691
1692                 pthread_mutex_lock(&target->mutex);
1693                 target->data_ready = 1;
1694                 pthread_cond_signal(&target->cond);
1695                 pthread_mutex_unlock(&target->mutex);
1696
1697                 if (!sub_size) {
1698                         pthread_join(target->thread, NULL);
1699                         pthread_cond_destroy(&target->cond);
1700                         pthread_mutex_destroy(&target->mutex);
1701                         active_threads--;
1702                 }
1703         }
1704 }
1705
1706 #else
1707 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1708 #endif
1709
1710 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1711 {
1712         unsigned char peeled[20];
1713
1714         if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
1715             !peel_ref(path, peeled)        && /* peelable? */
1716             !is_null_sha1(peeled)          && /* annotated tag? */
1717             locate_object_entry(peeled))      /* object packed? */
1718                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
1719         return 0;
1720 }
1721
1722 static void prepare_pack(int window, int depth)
1723 {
1724         struct object_entry **delta_list;
1725         uint32_t i, nr_deltas;
1726         unsigned n;
1727
1728         get_object_details();
1729
1730         /*
1731          * If we're locally repacking then we need to be doubly careful
1732          * from now on in order to make sure no stealth corruption gets
1733          * propagated to the new pack.  Clients receiving streamed packs
1734          * should validate everything they get anyway so no need to incur
1735          * the additional cost here in that case.
1736          */
1737         if (!pack_to_stdout)
1738                 do_check_packed_object_crc = 1;
1739
1740         if (!nr_objects || !window || !depth)
1741                 return;
1742
1743         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1744         nr_deltas = n = 0;
1745
1746         for (i = 0; i < nr_objects; i++) {
1747                 struct object_entry *entry = objects + i;
1748
1749                 if (entry->delta)
1750                         /* This happens if we decided to reuse existing
1751                          * delta from a pack.  "reuse_delta &&" is implied.
1752                          */
1753                         continue;
1754
1755                 if (entry->size < 50)
1756                         continue;
1757
1758                 if (entry->no_try_delta)
1759                         continue;
1760
1761                 if (!entry->preferred_base) {
1762                         nr_deltas++;
1763                         if (entry->type < 0)
1764                                 die("unable to get type of object %s",
1765                                     sha1_to_hex(entry->idx.sha1));
1766                 } else {
1767                         if (entry->type < 0) {
1768                                 /*
1769                                  * This object is not found, but we
1770                                  * don't have to include it anyway.
1771                                  */
1772                                 continue;
1773                         }
1774                 }
1775
1776                 delta_list[n++] = entry;
1777         }
1778
1779         if (nr_deltas && n > 1) {
1780                 unsigned nr_done = 0;
1781                 if (progress)
1782                         progress_state = start_progress("Compressing objects",
1783                                                         nr_deltas);
1784                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1785                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1786                 stop_progress(&progress_state);
1787                 if (nr_done != nr_deltas)
1788                         die("inconsistency with delta count");
1789         }
1790         free(delta_list);
1791 }
1792
1793 static int git_pack_config(const char *k, const char *v, void *cb)
1794 {
1795         if(!strcmp(k, "pack.window")) {
1796                 window = git_config_int(k, v);
1797                 return 0;
1798         }
1799         if (!strcmp(k, "pack.windowmemory")) {
1800                 window_memory_limit = git_config_ulong(k, v);
1801                 return 0;
1802         }
1803         if (!strcmp(k, "pack.depth")) {
1804                 depth = git_config_int(k, v);
1805                 return 0;
1806         }
1807         if (!strcmp(k, "pack.compression")) {
1808                 int level = git_config_int(k, v);
1809                 if (level == -1)
1810                         level = Z_DEFAULT_COMPRESSION;
1811                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1812                         die("bad pack compression level %d", level);
1813                 pack_compression_level = level;
1814                 pack_compression_seen = 1;
1815                 return 0;
1816         }
1817         if (!strcmp(k, "pack.deltacachesize")) {
1818                 max_delta_cache_size = git_config_int(k, v);
1819                 return 0;
1820         }
1821         if (!strcmp(k, "pack.deltacachelimit")) {
1822                 cache_max_small_delta_size = git_config_int(k, v);
1823                 return 0;
1824         }
1825         if (!strcmp(k, "pack.threads")) {
1826                 delta_search_threads = git_config_int(k, v);
1827                 if (delta_search_threads < 0)
1828                         die("invalid number of threads specified (%d)",
1829                             delta_search_threads);
1830 #ifndef THREADED_DELTA_SEARCH
1831                 if (delta_search_threads != 1)
1832                         warning("no threads support, ignoring %s", k);
1833 #endif
1834                 return 0;
1835         }
1836         if (!strcmp(k, "pack.indexversion")) {
1837                 pack_idx_default_version = git_config_int(k, v);
1838                 if (pack_idx_default_version > 2)
1839                         die("bad pack.indexversion=%"PRIu32,
1840                                 pack_idx_default_version);
1841                 return 0;
1842         }
1843         if (!strcmp(k, "pack.packsizelimit")) {
1844                 pack_size_limit_cfg = git_config_ulong(k, v);
1845                 return 0;
1846         }
1847         return git_default_config(k, v, cb);
1848 }
1849
1850 static void read_object_list_from_stdin(void)
1851 {
1852         char line[40 + 1 + PATH_MAX + 2];
1853         unsigned char sha1[20];
1854
1855         for (;;) {
1856                 if (!fgets(line, sizeof(line), stdin)) {
1857                         if (feof(stdin))
1858                                 break;
1859                         if (!ferror(stdin))
1860                                 die("fgets returned NULL, not EOF, not error!");
1861                         if (errno != EINTR)
1862                                 die("fgets: %s", strerror(errno));
1863                         clearerr(stdin);
1864                         continue;
1865                 }
1866                 if (line[0] == '-') {
1867                         if (get_sha1_hex(line+1, sha1))
1868                                 die("expected edge sha1, got garbage:\n %s",
1869                                     line);
1870                         add_preferred_base(sha1);
1871                         continue;
1872                 }
1873                 if (get_sha1_hex(line, sha1))
1874                         die("expected sha1, got garbage:\n %s", line);
1875
1876                 add_preferred_base_object(line+41);
1877                 add_object_entry(sha1, 0, line+41, 0);
1878         }
1879 }
1880
1881 #define OBJECT_ADDED (1u<<20)
1882
1883 static void show_commit(struct commit *commit)
1884 {
1885         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1886         commit->object.flags |= OBJECT_ADDED;
1887 }
1888
1889 static void show_object(struct object_array_entry *p)
1890 {
1891         add_preferred_base_object(p->name);
1892         add_object_entry(p->item->sha1, p->item->type, p->name, 0);
1893         p->item->flags |= OBJECT_ADDED;
1894 }
1895
1896 static void show_edge(struct commit *commit)
1897 {
1898         add_preferred_base(commit->object.sha1);
1899 }
1900
1901 struct in_pack_object {
1902         off_t offset;
1903         struct object *object;
1904 };
1905
1906 struct in_pack {
1907         int alloc;
1908         int nr;
1909         struct in_pack_object *array;
1910 };
1911
1912 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1913 {
1914         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1915         in_pack->array[in_pack->nr].object = object;
1916         in_pack->nr++;
1917 }
1918
1919 /*
1920  * Compare the objects in the offset order, in order to emulate the
1921  * "git rev-list --objects" output that produced the pack originally.
1922  */
1923 static int ofscmp(const void *a_, const void *b_)
1924 {
1925         struct in_pack_object *a = (struct in_pack_object *)a_;
1926         struct in_pack_object *b = (struct in_pack_object *)b_;
1927
1928         if (a->offset < b->offset)
1929                 return -1;
1930         else if (a->offset > b->offset)
1931                 return 1;
1932         else
1933                 return hashcmp(a->object->sha1, b->object->sha1);
1934 }
1935
1936 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1937 {
1938         struct packed_git *p;
1939         struct in_pack in_pack;
1940         uint32_t i;
1941
1942         memset(&in_pack, 0, sizeof(in_pack));
1943
1944         for (p = packed_git; p; p = p->next) {
1945                 const unsigned char *sha1;
1946                 struct object *o;
1947
1948                 for (i = 0; i < revs->num_ignore_packed; i++) {
1949                         if (matches_pack_name(p, revs->ignore_packed[i]))
1950                                 break;
1951                 }
1952                 if (revs->num_ignore_packed <= i)
1953                         continue;
1954                 if (open_pack_index(p))
1955                         die("cannot open pack index");
1956
1957                 ALLOC_GROW(in_pack.array,
1958                            in_pack.nr + p->num_objects,
1959                            in_pack.alloc);
1960
1961                 for (i = 0; i < p->num_objects; i++) {
1962                         sha1 = nth_packed_object_sha1(p, i);
1963                         o = lookup_unknown_object(sha1);
1964                         if (!(o->flags & OBJECT_ADDED))
1965                                 mark_in_pack_object(o, p, &in_pack);
1966                         o->flags |= OBJECT_ADDED;
1967                 }
1968         }
1969
1970         if (in_pack.nr) {
1971                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
1972                       ofscmp);
1973                 for (i = 0; i < in_pack.nr; i++) {
1974                         struct object *o = in_pack.array[i].object;
1975                         add_object_entry(o->sha1, o->type, "", 0);
1976                 }
1977         }
1978         free(in_pack.array);
1979 }
1980
1981 static void loosen_unused_packed_objects(struct rev_info *revs)
1982 {
1983         struct packed_git *p;
1984         uint32_t i;
1985         const unsigned char *sha1;
1986
1987         for (p = packed_git; p; p = p->next) {
1988                 for (i = 0; i < revs->num_ignore_packed; i++) {
1989                         if (matches_pack_name(p, revs->ignore_packed[i]))
1990                                 break;
1991                 }
1992                 if (revs->num_ignore_packed <= i)
1993                         continue;
1994
1995                 if (open_pack_index(p))
1996                         die("cannot open pack index");
1997
1998                 for (i = 0; i < p->num_objects; i++) {
1999                         sha1 = nth_packed_object_sha1(p, i);
2000                         if (!locate_object_entry(sha1))
2001                                 if (force_object_loose(sha1, p->mtime))
2002                                         die("unable to force loose object");
2003                 }
2004         }
2005 }
2006
2007 static void get_object_list(int ac, const char **av)
2008 {
2009         struct rev_info revs;
2010         char line[1000];
2011         int flags = 0;
2012
2013         init_revisions(&revs, NULL);
2014         save_commit_buffer = 0;
2015         setup_revisions(ac, av, &revs, NULL);
2016
2017         while (fgets(line, sizeof(line), stdin) != NULL) {
2018                 int len = strlen(line);
2019                 if (len && line[len - 1] == '\n')
2020                         line[--len] = 0;
2021                 if (!len)
2022                         break;
2023                 if (*line == '-') {
2024                         if (!strcmp(line, "--not")) {
2025                                 flags ^= UNINTERESTING;
2026                                 continue;
2027                         }
2028                         die("not a rev '%s'", line);
2029                 }
2030                 if (handle_revision_arg(line, &revs, flags, 1))
2031                         die("bad revision '%s'", line);
2032         }
2033
2034         if (prepare_revision_walk(&revs))
2035                 die("revision walk setup failed");
2036         mark_edges_uninteresting(revs.commits, &revs, show_edge);
2037         traverse_commit_list(&revs, show_commit, show_object);
2038
2039         if (keep_unreachable)
2040                 add_objects_in_unpacked_packs(&revs);
2041         if (unpack_unreachable)
2042                 loosen_unused_packed_objects(&revs);
2043 }
2044
2045 static int adjust_perm(const char *path, mode_t mode)
2046 {
2047         if (chmod(path, mode))
2048                 return -1;
2049         return adjust_shared_perm(path);
2050 }
2051
2052 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2053 {
2054         int use_internal_rev_list = 0;
2055         int thin = 0;
2056         uint32_t i;
2057         const char **rp_av;
2058         int rp_ac_alloc = 64;
2059         int rp_ac;
2060
2061         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2062
2063         rp_av[0] = "pack-objects";
2064         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2065         rp_ac = 2;
2066
2067         git_config(git_pack_config, NULL);
2068         if (!pack_compression_seen && core_compression_seen)
2069                 pack_compression_level = core_compression_level;
2070
2071         progress = isatty(2);
2072         for (i = 1; i < argc; i++) {
2073                 const char *arg = argv[i];
2074
2075                 if (*arg != '-')
2076                         break;
2077
2078                 if (!strcmp("--non-empty", arg)) {
2079                         non_empty = 1;
2080                         continue;
2081                 }
2082                 if (!strcmp("--local", arg)) {
2083                         local = 1;
2084                         continue;
2085                 }
2086                 if (!strcmp("--incremental", arg)) {
2087                         incremental = 1;
2088                         continue;
2089                 }
2090                 if (!prefixcmp(arg, "--compression=")) {
2091                         char *end;
2092                         int level = strtoul(arg+14, &end, 0);
2093                         if (!arg[14] || *end)
2094                                 usage(pack_usage);
2095                         if (level == -1)
2096                                 level = Z_DEFAULT_COMPRESSION;
2097                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2098                                 die("bad pack compression level %d", level);
2099                         pack_compression_level = level;
2100                         continue;
2101                 }
2102                 if (!prefixcmp(arg, "--max-pack-size=")) {
2103                         char *end;
2104                         pack_size_limit_cfg = 0;
2105                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2106                         if (!arg[16] || *end)
2107                                 usage(pack_usage);
2108                         continue;
2109                 }
2110                 if (!prefixcmp(arg, "--window=")) {
2111                         char *end;
2112                         window = strtoul(arg+9, &end, 0);
2113                         if (!arg[9] || *end)
2114                                 usage(pack_usage);
2115                         continue;
2116                 }
2117                 if (!prefixcmp(arg, "--window-memory=")) {
2118                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2119                                 usage(pack_usage);
2120                         continue;
2121                 }
2122                 if (!prefixcmp(arg, "--threads=")) {
2123                         char *end;
2124                         delta_search_threads = strtoul(arg+10, &end, 0);
2125                         if (!arg[10] || *end || delta_search_threads < 0)
2126                                 usage(pack_usage);
2127 #ifndef THREADED_DELTA_SEARCH
2128                         if (delta_search_threads != 1)
2129                                 warning("no threads support, "
2130                                         "ignoring %s", arg);
2131 #endif
2132                         continue;
2133                 }
2134                 if (!prefixcmp(arg, "--depth=")) {
2135                         char *end;
2136                         depth = strtoul(arg+8, &end, 0);
2137                         if (!arg[8] || *end)
2138                                 usage(pack_usage);
2139                         continue;
2140                 }
2141                 if (!strcmp("--progress", arg)) {
2142                         progress = 1;
2143                         continue;
2144                 }
2145                 if (!strcmp("--all-progress", arg)) {
2146                         progress = 2;
2147                         continue;
2148                 }
2149                 if (!strcmp("-q", arg)) {
2150                         progress = 0;
2151                         continue;
2152                 }
2153                 if (!strcmp("--no-reuse-delta", arg)) {
2154                         reuse_delta = 0;
2155                         continue;
2156                 }
2157                 if (!strcmp("--no-reuse-object", arg)) {
2158                         reuse_object = reuse_delta = 0;
2159                         continue;
2160                 }
2161                 if (!strcmp("--delta-base-offset", arg)) {
2162                         allow_ofs_delta = 1;
2163                         continue;
2164                 }
2165                 if (!strcmp("--stdout", arg)) {
2166                         pack_to_stdout = 1;
2167                         continue;
2168                 }
2169                 if (!strcmp("--revs", arg)) {
2170                         use_internal_rev_list = 1;
2171                         continue;
2172                 }
2173                 if (!strcmp("--keep-unreachable", arg)) {
2174                         keep_unreachable = 1;
2175                         continue;
2176                 }
2177                 if (!strcmp("--unpack-unreachable", arg)) {
2178                         unpack_unreachable = 1;
2179                         continue;
2180                 }
2181                 if (!strcmp("--include-tag", arg)) {
2182                         include_tag = 1;
2183                         continue;
2184                 }
2185                 if (!strcmp("--unpacked", arg) ||
2186                     !prefixcmp(arg, "--unpacked=") ||
2187                     !strcmp("--reflog", arg) ||
2188                     !strcmp("--all", arg)) {
2189                         use_internal_rev_list = 1;
2190                         if (rp_ac >= rp_ac_alloc - 1) {
2191                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2192                                 rp_av = xrealloc(rp_av,
2193                                                  rp_ac_alloc * sizeof(*rp_av));
2194                         }
2195                         rp_av[rp_ac++] = arg;
2196                         continue;
2197                 }
2198                 if (!strcmp("--thin", arg)) {
2199                         use_internal_rev_list = 1;
2200                         thin = 1;
2201                         rp_av[1] = "--objects-edge";
2202                         continue;
2203                 }
2204                 if (!prefixcmp(arg, "--index-version=")) {
2205                         char *c;
2206                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2207                         if (pack_idx_default_version > 2)
2208                                 die("bad %s", arg);
2209                         if (*c == ',')
2210                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2211                         if (*c || pack_idx_off32_limit & 0x80000000)
2212                                 die("bad %s", arg);
2213                         continue;
2214                 }
2215                 usage(pack_usage);
2216         }
2217
2218         /* Traditionally "pack-objects [options] base extra" failed;
2219          * we would however want to take refs parameter that would
2220          * have been given to upstream rev-list ourselves, which means
2221          * we somehow want to say what the base name is.  So the
2222          * syntax would be:
2223          *
2224          * pack-objects [options] base <refs...>
2225          *
2226          * in other words, we would treat the first non-option as the
2227          * base_name and send everything else to the internal revision
2228          * walker.
2229          */
2230
2231         if (!pack_to_stdout)
2232                 base_name = argv[i++];
2233
2234         if (pack_to_stdout != !base_name)
2235                 usage(pack_usage);
2236
2237         if (!pack_to_stdout && !pack_size_limit)
2238                 pack_size_limit = pack_size_limit_cfg;
2239
2240         if (pack_to_stdout && pack_size_limit)
2241                 die("--max-pack-size cannot be used to build a pack for transfer.");
2242
2243         if (!pack_to_stdout && thin)
2244                 die("--thin cannot be used to build an indexable pack.");
2245
2246         if (keep_unreachable && unpack_unreachable)
2247                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2248
2249 #ifdef THREADED_DELTA_SEARCH
2250         if (!delta_search_threads)      /* --threads=0 means autodetect */
2251                 delta_search_threads = online_cpus();
2252 #endif
2253
2254         prepare_packed_git();
2255
2256         if (progress)
2257                 progress_state = start_progress("Counting objects", 0);
2258         if (!use_internal_rev_list)
2259                 read_object_list_from_stdin();
2260         else {
2261                 rp_av[rp_ac] = NULL;
2262                 get_object_list(rp_ac, rp_av);
2263         }
2264         if (include_tag && nr_result)
2265                 for_each_ref(add_ref_tag, NULL);
2266         stop_progress(&progress_state);
2267
2268         if (non_empty && !nr_result)
2269                 return 0;
2270         if (nr_result)
2271                 prepare_pack(window, depth);
2272         write_pack_file();
2273         if (progress)
2274                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2275                         " reused %"PRIu32" (delta %"PRIu32")\n",
2276                         written, written_delta, reused, reused_delta);
2277         return 0;
2278 }