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

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "attr.h"
   4 #include "object.h"
   5 #include "blob.h"
   6 #include "commit.h"
   7 #include "tag.h"
   8 #include "tree.h"
   9 #include "delta.h"
  10 #include "pack.h"
  11 #include "csum-file.h"
  12 #include "tree-walk.h"
  13 #include "diff.h"
  14 #include "revision.h"
  15 #include "list-objects.h"
  16 #include "progress.h"
  17
  18 #ifdef THREADED_DELTA_SEARCH
  19 #include "thread-utils.h"
  20 #include <pthread.h>
  21 #endif
  22
  23 static const char pack_usage[] = "\
  24 git-pack-objects [{ -q | --progress | --all-progress }] \n\
  25         [--max-pack-size=N] [--local] [--incremental] \n\
  26         [--window=N] [--window-memory=N] [--depth=N] \n\
  27         [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
  28         [--threads=N] [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
  29         [--stdout | base-name] [--keep-unreachable] [<ref-list | <object-list]";
  30
  31 struct object_entry {
  32         struct pack_idx_entry idx;
  33         unsigned long size;     /* uncompressed size */
  34         struct packed_git *in_pack;     /* already in pack */
  35         off_t in_pack_offset;
  36         struct object_entry *delta;     /* delta base object */
  37         struct object_entry *delta_child; /* deltified objects who bases me */
  38         struct object_entry *delta_sibling; /* other deltified objects who
  39                                              * uses the same base as me
  40                                              */
  41         void *delta_data;       /* cached delta (uncompressed) */
  42         unsigned long delta_size;       /* delta data size (uncompressed) */
  43         unsigned int hash;      /* name hint hash */
  44         enum object_type type;
  45         enum object_type in_pack_type;  /* could be delta */
  46         unsigned char in_pack_header_size;
  47         unsigned char preferred_base; /* we do not pack this, but is available
  48                                        * to be used as the base object to delta
  49                                        * objects against.
  50                                        */
  51         unsigned char no_try_delta;
  52 };
  53
  54 /*
  55  * Objects we are going to pack are collected in objects array (dynamically
  56  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  57  * in the order we see -- typically rev-list --objects order that gives us
  58  * nice "minimum seek" order.
  59  */
  60 static struct object_entry *objects;
  61 static struct pack_idx_entry **written_list;
  62 static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
  63
  64 static int non_empty;
  65 static int no_reuse_delta, no_reuse_object, keep_unreachable;
  66 static int local;
  67 static int incremental;
  68 static int allow_ofs_delta;
  69 static const char *base_name;
  70 static int progress = 1;
  71 static int window = 10;
  72 static uint32_t pack_size_limit, pack_size_limit_cfg;
  73 static int depth = 50;
  74 static int delta_search_threads = 1;
  75 static int pack_to_stdout;
  76 static int num_preferred_base;
  77 static struct progress *progress_state;
  78 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
  79 static int pack_compression_seen;
  80
  81 static unsigned long delta_cache_size = 0;
  82 static unsigned long max_delta_cache_size = 0;
  83 static unsigned long cache_max_small_delta_size = 1000;
  84
  85 static unsigned long window_memory_limit = 0;
  86
  87 /*
  88  * The object names in objects array are hashed with this hashtable,
  89  * to help looking up the entry by object name.
  90  * This hashtable is built after all the objects are seen.
  91  */
  92 static int *object_ix;
  93 static int object_ix_hashsz;
  94
  95 /*
  96  * Pack index for existing packs give us easy access to the offsets into
  97  * corresponding pack file where each object's data starts, but the entries
  98  * do not store the size of the compressed representation (uncompressed
  99  * size is easily available by examining the pack entry header).  It is
 100  * also rather expensive to find the sha1 for an object given its offset.
 101  *
 102  * We build a hashtable of existing packs (pack_revindex), and keep reverse
 103  * index here -- pack index file is sorted by object name mapping to offset;
 104  * this pack_revindex[].revindex array is a list of offset/index_nr pairs
 105  * ordered by offset, so if you know the offset of an object, next offset
 106  * is where its packed representation ends and the index_nr can be used to
 107  * get the object sha1 from the main index.
 108  */
 109 struct revindex_entry {
 110         off_t offset;
 111         unsigned int nr;
 112 };
 113 struct pack_revindex {
 114         struct packed_git *p;
 115         struct revindex_entry *revindex;
 116 };
 117 static struct  pack_revindex *pack_revindex;
 118 static int pack_revindex_hashsz;
 119
 120 /*
 121  * stats
 122  */
 123 static uint32_t written, written_delta;
 124 static uint32_t reused, reused_delta;
 125
 126 static int pack_revindex_ix(struct packed_git *p)
 127 {
 128         unsigned long ui = (unsigned long)p;
 129         int i;
 130
 131         ui = ui ^ (ui >> 16); /* defeat structure alignment */
 132         i = (int)(ui % pack_revindex_hashsz);
 133         while (pack_revindex[i].p) {
 134                 if (pack_revindex[i].p == p)
 135                         return i;
 136                 if (++i == pack_revindex_hashsz)
 137                         i = 0;
 138         }
 139         return -1 - i;
 140 }
 141
 142 static void prepare_pack_ix(void)
 143 {
 144         int num;
 145         struct packed_git *p;
 146         for (num = 0, p = packed_git; p; p = p->next)
 147                 num++;
 148         if (!num)
 149                 return;
 150         pack_revindex_hashsz = num * 11;
 151         pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
 152         for (p = packed_git; p; p = p->next) {
 153                 num = pack_revindex_ix(p);
 154                 num = - 1 - num;
 155                 pack_revindex[num].p = p;
 156         }
 157         /* revindex elements are lazily initialized */
 158 }
 159
 160 static int cmp_offset(const void *a_, const void *b_)
 161 {
 162         const struct revindex_entry *a = a_;
 163         const struct revindex_entry *b = b_;
 164         return (a->offset < b->offset) ? -1 : (a->offset > b->offset) ? 1 : 0;
 165 }
 166
 167 /*
 168  * Ordered list of offsets of objects in the pack.
 169  */
 170 static void prepare_pack_revindex(struct pack_revindex *rix)
 171 {
 172         struct packed_git *p = rix->p;
 173         int num_ent = p->num_objects;
 174         int i;
 175         const char *index = p->index_data;
 176
 177         rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1));
 178         index += 4 * 256;
 179
 180         if (p->index_version > 1) {
 181                 const uint32_t *off_32 =
 182                         (uint32_t *)(index + 8 + p->num_objects * (20 + 4));
 183                 const uint32_t *off_64 = off_32 + p->num_objects;
 184                 for (i = 0; i < num_ent; i++) {
 185                         uint32_t off = ntohl(*off_32++);
 186                         if (!(off & 0x80000000)) {
 187                                 rix->revindex[i].offset = off;
 188                         } else {
 189                                 rix->revindex[i].offset =
 190                                         ((uint64_t)ntohl(*off_64++)) << 32;
 191                                 rix->revindex[i].offset |=
 192                                         ntohl(*off_64++);
 193                         }
 194                         rix->revindex[i].nr = i;
 195                 }
 196         } else {
 197                 for (i = 0; i < num_ent; i++) {
 198                         uint32_t hl = *((uint32_t *)(index + 24 * i));
 199                         rix->revindex[i].offset = ntohl(hl);
 200                         rix->revindex[i].nr = i;
 201                 }
 202         }
 203
 204         /* This knows the pack format -- the 20-byte trailer
 205          * follows immediately after the last object data.
 206          */
 207         rix->revindex[num_ent].offset = p->pack_size - 20;
 208         rix->revindex[num_ent].nr = -1;
 209         qsort(rix->revindex, num_ent, sizeof(*rix->revindex), cmp_offset);
 210 }
 211
 212 static struct revindex_entry * find_packed_object(struct packed_git *p,
 213                                                   off_t ofs)
 214 {
 215         int num;
 216         int lo, hi;
 217         struct pack_revindex *rix;
 218         struct revindex_entry *revindex;
 219         num = pack_revindex_ix(p);
 220         if (num < 0)
 221                 die("internal error: pack revindex uninitialized");
 222         rix = &pack_revindex[num];
 223         if (!rix->revindex)
 224                 prepare_pack_revindex(rix);
 225         revindex = rix->revindex;
 226         lo = 0;
 227         hi = p->num_objects + 1;
 228         do {
 229                 int mi = (lo + hi) / 2;
 230                 if (revindex[mi].offset == ofs) {
 231                         return revindex + mi;
 232                 }
 233                 else if (ofs < revindex[mi].offset)
 234                         hi = mi;
 235                 else
 236                         lo = mi + 1;
 237         } while (lo < hi);
 238         die("internal error: pack revindex corrupt");
 239 }
 240
 241 static const unsigned char *find_packed_object_name(struct packed_git *p,
 242                                                     off_t ofs)
 243 {
 244         struct revindex_entry *entry = find_packed_object(p, ofs);
 245         return nth_packed_object_sha1(p, entry->nr);
 246 }
 247
 248 static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
 249 {
 250         unsigned long othersize, delta_size;
 251         enum object_type type;
 252         void *otherbuf = read_sha1_file(entry->delta->idx.sha1, &type, &othersize);
 253         void *delta_buf;
 254
 255         if (!otherbuf)
 256                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
 257         delta_buf = diff_delta(otherbuf, othersize,
 258                                buf, size, &delta_size, 0);
 259         if (!delta_buf || delta_size != entry->delta_size)
 260                 die("delta size changed");
 261         free(buf);
 262         free(otherbuf);
 263         return delta_buf;
 264 }
 265
 266 /*
 267  * The per-object header is a pretty dense thing, which is
 268  *  - first byte: low four bits are "size", then three bits of "type",
 269  *    and the high bit is "size continues".
 270  *  - each byte afterwards: low seven bits are size continuation,
 271  *    with the high bit being "size continues"
 272  */
 273 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 274 {
 275         int n = 1;
 276         unsigned char c;
 277
 278         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 279                 die("bad type %d", type);
 280
 281         c = (type << 4) | (size & 15);
 282         size >>= 4;
 283         while (size) {
 284                 *hdr++ = c | 0x80;
 285                 c = size & 0x7f;
 286                 size >>= 7;
 287                 n++;
 288         }
 289         *hdr = c;
 290         return n;
 291 }
 292
 293 /*
 294  * we are going to reuse the existing object data as is.  make
 295  * sure it is not corrupt.
 296  */
 297 static int check_pack_inflate(struct packed_git *p,
 298                 struct pack_window **w_curs,
 299                 off_t offset,
 300                 off_t len,
 301                 unsigned long expect)
 302 {
 303         z_stream stream;
 304         unsigned char fakebuf[4096], *in;
 305         int st;
 306
 307         memset(&stream, 0, sizeof(stream));
 308         inflateInit(&stream);
 309         do {
 310                 in = use_pack(p, w_curs, offset, &stream.avail_in);
 311                 stream.next_in = in;
 312                 stream.next_out = fakebuf;
 313                 stream.avail_out = sizeof(fakebuf);
 314                 st = inflate(&stream, Z_FINISH);
 315                 offset += stream.next_in - in;
 316         } while (st == Z_OK || st == Z_BUF_ERROR);
 317         inflateEnd(&stream);
 318         return (st == Z_STREAM_END &&
 319                 stream.total_out == expect &&
 320                 stream.total_in == len) ? 0 : -1;
 321 }
 322
 323 static int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
 324                           off_t offset, off_t len, unsigned int nr)
 325 {
 326         const uint32_t *index_crc;
 327         uint32_t data_crc = crc32(0, Z_NULL, 0);
 328
 329         do {
 330                 unsigned int avail;
 331                 void *data = use_pack(p, w_curs, offset, &avail);
 332                 if (avail > len)
 333                         avail = len;
 334                 data_crc = crc32(data_crc, data, avail);
 335                 offset += avail;
 336                 len -= avail;
 337         } while (len);
 338
 339         index_crc = p->index_data;
 340         index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
 341
 342         return data_crc != ntohl(*index_crc);
 343 }
 344
 345 static void copy_pack_data(struct sha1file *f,
 346                 struct packed_git *p,
 347                 struct pack_window **w_curs,
 348                 off_t offset,
 349                 off_t len)
 350 {
 351         unsigned char *in;
 352         unsigned int avail;
 353
 354         while (len) {
 355                 in = use_pack(p, w_curs, offset, &avail);
 356                 if (avail > len)
 357                         avail = (unsigned int)len;
 358                 sha1write(f, in, avail);
 359                 offset += avail;
 360                 len -= avail;
 361         }
 362 }
 363
 364 static unsigned long write_object(struct sha1file *f,
 365                                   struct object_entry *entry,
 366                                   off_t write_offset)
 367 {
 368         unsigned long size;
 369         enum object_type type;
 370         void *buf;
 371         unsigned char header[10];
 372         unsigned char dheader[10];
 373         unsigned hdrlen;
 374         off_t datalen;
 375         enum object_type obj_type;
 376         int to_reuse = 0;
 377         /* write limit if limited packsize and not first object */
 378         unsigned long limit = pack_size_limit && nr_written ?
 379                                 pack_size_limit - write_offset : 0;
 380                                 /* no if no delta */
 381         int usable_delta =      !entry->delta ? 0 :
 382                                 /* yes if unlimited packfile */
 383                                 !pack_size_limit ? 1 :
 384                                 /* no if base written to previous pack */
 385                                 entry->delta->idx.offset == (off_t)-1 ? 0 :
 386                                 /* otherwise double-check written to this
 387                                  * pack,  like we do below
 388                                  */
 389                                 entry->delta->idx.offset ? 1 : 0;
 390
 391         if (!pack_to_stdout)
 392                 crc32_begin(f);
 393
 394         obj_type = entry->type;
 395         if (no_reuse_object)
 396                 to_reuse = 0;   /* explicit */
 397         else if (!entry->in_pack)
 398                 to_reuse = 0;   /* can't reuse what we don't have */
 399         else if (obj_type == OBJ_REF_DELTA || obj_type == OBJ_OFS_DELTA)
 400                                 /* check_object() decided it for us ... */
 401                 to_reuse = usable_delta;
 402                                 /* ... but pack split may override that */
 403         else if (obj_type != entry->in_pack_type)
 404                 to_reuse = 0;   /* pack has delta which is unusable */
 405         else if (entry->delta)
 406                 to_reuse = 0;   /* we want to pack afresh */
 407         else
 408                 to_reuse = 1;   /* we have it in-pack undeltified,
 409                                  * and we do not need to deltify it.
 410                                  */
 411
 412         if (!to_reuse) {
 413                 z_stream stream;
 414                 unsigned long maxsize;
 415                 void *out;
 416                 if (!usable_delta) {
 417                         buf = read_sha1_file(entry->idx.sha1, &obj_type, &size);
 418                         if (!buf)
 419                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 420                 } else if (entry->delta_data) {
 421                         size = entry->delta_size;
 422                         buf = entry->delta_data;
 423                         entry->delta_data = NULL;
 424                         obj_type = (allow_ofs_delta && entry->delta->idx.offset) ?
 425                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 426                 } else {
 427                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
 428                         if (!buf)
 429                                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
 430                         buf = delta_against(buf, size, entry);
 431                         size = entry->delta_size;
 432                         obj_type = (allow_ofs_delta && entry->delta->idx.offset) ?
 433                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 434                 }
 435                 /* compress the data to store and put compressed length in datalen */
 436                 memset(&stream, 0, sizeof(stream));
 437                 deflateInit(&stream, pack_compression_level);
 438                 maxsize = deflateBound(&stream, size);
 439                 out = xmalloc(maxsize);
 440                 /* Compress it */
 441                 stream.next_in = buf;
 442                 stream.avail_in = size;
 443                 stream.next_out = out;
 444                 stream.avail_out = maxsize;
 445                 while (deflate(&stream, Z_FINISH) == Z_OK)
 446                         /* nothing */;
 447                 deflateEnd(&stream);
 448                 datalen = stream.total_out;
 449
 450                 /*
 451                  * The object header is a byte of 'type' followed by zero or
 452                  * more bytes of length.
 453                  */
 454                 hdrlen = encode_header(obj_type, size, header);
 455
 456                 if (obj_type == OBJ_OFS_DELTA) {
 457                         /*
 458                          * Deltas with relative base contain an additional
 459                          * encoding of the relative offset for the delta
 460                          * base from this object's position in the pack.
 461                          */
 462                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 463                         unsigned pos = sizeof(dheader) - 1;
 464                         dheader[pos] = ofs & 127;
 465                         while (ofs >>= 7)
 466                                 dheader[--pos] = 128 | (--ofs & 127);
 467                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
 468                                 free(out);
 469                                 free(buf);
 470                                 return 0;
 471                         }
 472                         sha1write(f, header, hdrlen);
 473                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 474                         hdrlen += sizeof(dheader) - pos;
 475                 } else if (obj_type == OBJ_REF_DELTA) {
 476                         /*
 477                          * Deltas with a base reference contain
 478                          * an additional 20 bytes for the base sha1.
 479                          */
 480                         if (limit && hdrlen + 20 + datalen + 20 >= limit) {
 481                                 free(out);
 482                                 free(buf);
 483                                 return 0;
 484                         }
 485                         sha1write(f, header, hdrlen);
 486                         sha1write(f, entry->delta->idx.sha1, 20);
 487                         hdrlen += 20;
 488                 } else {
 489                         if (limit && hdrlen + datalen + 20 >= limit) {
 490                                 free(out);
 491                                 free(buf);
 492                                 return 0;
 493                         }
 494                         sha1write(f, header, hdrlen);
 495                 }
 496                 sha1write(f, out, datalen);
 497                 free(out);
 498                 free(buf);
 499         }
 500         else {
 501                 struct packed_git *p = entry->in_pack;
 502                 struct pack_window *w_curs = NULL;
 503                 struct revindex_entry *revidx;
 504                 off_t offset;
 505
 506                 if (entry->delta) {
 507                         obj_type = (allow_ofs_delta && entry->delta->idx.offset) ?
 508                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
 509                         reused_delta++;
 510                 }
 511                 hdrlen = encode_header(obj_type, entry->size, header);
 512                 offset = entry->in_pack_offset;
 513                 revidx = find_packed_object(p, offset);
 514                 datalen = revidx[1].offset - offset;
 515                 if (!pack_to_stdout && p->index_version > 1 &&
 516                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
 517                         die("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
 518                 offset += entry->in_pack_header_size;
 519                 datalen -= entry->in_pack_header_size;
 520                 if (obj_type == OBJ_OFS_DELTA) {
 521                         off_t ofs = entry->idx.offset - entry->delta->idx.offset;
 522                         unsigned pos = sizeof(dheader) - 1;
 523                         dheader[pos] = ofs & 127;
 524                         while (ofs >>= 7)
 525                                 dheader[--pos] = 128 | (--ofs & 127);
 526                         if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit)
 527                                 return 0;
 528                         sha1write(f, header, hdrlen);
 529                         sha1write(f, dheader + pos, sizeof(dheader) - pos);
 530                         hdrlen += sizeof(dheader) - pos;
 531                 } else if (obj_type == OBJ_REF_DELTA) {
 532                         if (limit && hdrlen + 20 + datalen + 20 >= limit)
 533                                 return 0;
 534                         sha1write(f, header, hdrlen);
 535                         sha1write(f, entry->delta->idx.sha1, 20);
 536                         hdrlen += 20;
 537                 } else {
 538                         if (limit && hdrlen + datalen + 20 >= limit)
 539                                 return 0;
 540                         sha1write(f, header, hdrlen);
 541                 }
 542
 543                 if (!pack_to_stdout && p->index_version == 1 &&
 544                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
 545                         die("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
 546                 copy_pack_data(f, p, &w_curs, offset, datalen);
 547                 unuse_pack(&w_curs);
 548                 reused++;
 549         }
 550         if (usable_delta)
 551                 written_delta++;
 552         written++;
 553         if (!pack_to_stdout)
 554                 entry->idx.crc32 = crc32_end(f);
 555         return hdrlen + datalen;
 556 }
 557
 558 static off_t write_one(struct sha1file *f,
 559                                struct object_entry *e,
 560                                off_t offset)
 561 {
 562         unsigned long size;
 563
 564         /* offset is non zero if object is written already. */
 565         if (e->idx.offset || e->preferred_base)
 566                 return offset;
 567
 568         /* if we are deltified, write out base object first. */
 569         if (e->delta) {
 570                 offset = write_one(f, e->delta, offset);
 571                 if (!offset)
 572                         return 0;
 573         }
 574
 575         e->idx.offset = offset;
 576         size = write_object(f, e, offset);
 577         if (!size) {
 578                 e->idx.offset = 0;
 579                 return 0;
 580         }
 581         written_list[nr_written++] = &e->idx;
 582
 583         /* make sure off_t is sufficiently large not to wrap */
 584         if (offset > offset + size)
 585                 die("pack too large for current definition of off_t");
 586         return offset + size;
 587 }
 588
 589 /* forward declaration for write_pack_file */
 590 static int adjust_perm(const char *path, mode_t mode);
 591
 592 static void write_pack_file(void)
 593 {
 594         uint32_t i = 0, j;
 595         struct sha1file *f;
 596         off_t offset, offset_one, last_obj_offset = 0;
 597         struct pack_header hdr;
 598         int do_progress = progress >> pack_to_stdout;
 599         uint32_t nr_remaining = nr_result;
 600
 601         if (do_progress)
 602                 progress_state = start_progress("Writing objects", nr_result);
 603         written_list = xmalloc(nr_objects * sizeof(*written_list));
 604
 605         do {
 606                 unsigned char sha1[20];
 607                 char *pack_tmp_name = NULL;
 608
 609                 if (pack_to_stdout) {
 610                         f = sha1fd_throughput(1, "<stdout>", progress_state);
 611                 } else {
 612                         char tmpname[PATH_MAX];
 613                         int fd;
 614                         snprintf(tmpname, sizeof(tmpname),
 615                                  "%s/tmp_pack_XXXXXX", get_object_directory());
 616                         fd = xmkstemp(tmpname);
 617                         pack_tmp_name = xstrdup(tmpname);
 618                         f = sha1fd(fd, pack_tmp_name);
 619                 }
 620
 621                 hdr.hdr_signature = htonl(PACK_SIGNATURE);
 622                 hdr.hdr_version = htonl(PACK_VERSION);
 623                 hdr.hdr_entries = htonl(nr_remaining);
 624                 sha1write(f, &hdr, sizeof(hdr));
 625                 offset = sizeof(hdr);
 626                 nr_written = 0;
 627                 for (; i < nr_objects; i++) {
 628                         last_obj_offset = offset;
 629                         offset_one = write_one(f, objects + i, offset);
 630                         if (!offset_one)
 631                                 break;
 632                         offset = offset_one;
 633                         display_progress(progress_state, written);
 634                 }
 635
 636                 /*
 637                  * Did we write the wrong # entries in the header?
 638                  * If so, rewrite it like in fast-import
 639                  */
 640                 if (pack_to_stdout || nr_written == nr_remaining) {
 641                         sha1close(f, sha1, 1);
 642                 } else {
 643                         int fd = sha1close(f, NULL, 0);
 644                         fixup_pack_header_footer(fd, sha1, pack_tmp_name, nr_written);
 645                         close(fd);
 646                 }
 647
 648                 if (!pack_to_stdout) {
 649                         mode_t mode = umask(0);
 650                         char *idx_tmp_name, tmpname[PATH_MAX];
 651
 652                         umask(mode);
 653                         mode = 0444 & ~mode;
 654
 655                         idx_tmp_name = write_idx_file(NULL, written_list,
 656                                                       nr_written, sha1);
 657                         snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
 658                                  base_name, sha1_to_hex(sha1));
 659                         if (adjust_perm(pack_tmp_name, mode))
 660                                 die("unable to make temporary pack file readable: %s",
 661                                     strerror(errno));
 662                         if (rename(pack_tmp_name, tmpname))
 663                                 die("unable to rename temporary pack file: %s",
 664                                     strerror(errno));
 665                         snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
 666                                  base_name, sha1_to_hex(sha1));
 667                         if (adjust_perm(idx_tmp_name, mode))
 668                                 die("unable to make temporary index file readable: %s",
 669                                     strerror(errno));
 670                         if (rename(idx_tmp_name, tmpname))
 671                                 die("unable to rename temporary index file: %s",
 672                                     strerror(errno));
 673                         free(idx_tmp_name);
 674                         free(pack_tmp_name);
 675                         puts(sha1_to_hex(sha1));
 676                 }
 677
 678                 /* mark written objects as written to previous pack */
 679                 for (j = 0; j < nr_written; j++) {
 680                         written_list[j]->offset = (off_t)-1;
 681                 }
 682                 nr_remaining -= nr_written;
 683         } while (nr_remaining && i < nr_objects);
 684
 685         free(written_list);
 686         stop_progress(&progress_state);
 687         if (written != nr_result)
 688                 die("wrote %u objects while expecting %u", written, nr_result);
 689         /*
 690          * We have scanned through [0 ... i).  Since we have written
 691          * the correct number of objects,  the remaining [i ... nr_objects)
 692          * items must be either already written (due to out-of-order delta base)
 693          * or a preferred base.  Count those which are neither and complain if any.
 694          */
 695         for (j = 0; i < nr_objects; i++) {
 696                 struct object_entry *e = objects + i;
 697                 j += !e->idx.offset && !e->preferred_base;
 698         }
 699         if (j)
 700                 die("wrote %u objects as expected but %u unwritten", written, j);
 701 }
 702
 703 static int locate_object_entry_hash(const unsigned char *sha1)
 704 {
 705         int i;
 706         unsigned int ui;
 707         memcpy(&ui, sha1, sizeof(unsigned int));
 708         i = ui % object_ix_hashsz;
 709         while (0 < object_ix[i]) {
 710                 if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
 711                         return i;
 712                 if (++i == object_ix_hashsz)
 713                         i = 0;
 714         }
 715         return -1 - i;
 716 }
 717
 718 static struct object_entry *locate_object_entry(const unsigned char *sha1)
 719 {
 720         int i;
 721
 722         if (!object_ix_hashsz)
 723                 return NULL;
 724
 725         i = locate_object_entry_hash(sha1);
 726         if (0 <= i)
 727                 return &objects[object_ix[i]-1];
 728         return NULL;
 729 }
 730
 731 static void rehash_objects(void)
 732 {
 733         uint32_t i;
 734         struct object_entry *oe;
 735
 736         object_ix_hashsz = nr_objects * 3;
 737         if (object_ix_hashsz < 1024)
 738                 object_ix_hashsz = 1024;
 739         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 740         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 741         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 742                 int ix = locate_object_entry_hash(oe->idx.sha1);
 743                 if (0 <= ix)
 744                         continue;
 745                 ix = -1 - ix;
 746                 object_ix[ix] = i + 1;
 747         }
 748 }
 749
 750 static unsigned name_hash(const char *name)
 751 {
 752         unsigned char c;
 753         unsigned hash = 0;
 754
 755         if (!name)
 756                 return 0;
 757
 758         /*
 759          * This effectively just creates a sortable number from the
 760          * last sixteen non-whitespace characters. Last characters
 761          * count "most", so things that end in ".c" sort together.
 762          */
 763         while ((c = *name++) != 0) {
 764                 if (isspace(c))
 765                         continue;
 766                 hash = (hash >> 2) + (c << 24);
 767         }
 768         return hash;
 769 }
 770
 771 static void setup_delta_attr_check(struct git_attr_check *check)
 772 {
 773         static struct git_attr *attr_delta;
 774
 775         if (!attr_delta)
 776                 attr_delta = git_attr("delta", 5);
 777
 778         check[0].attr = attr_delta;
 779 }
 780
 781 static int no_try_delta(const char *path)
 782 {
 783         struct git_attr_check check[1];
 784
 785         setup_delta_attr_check(check);
 786         if (git_checkattr(path, ARRAY_SIZE(check), check))
 787                 return 0;
 788         if (ATTR_FALSE(check->value))
 789                 return 1;
 790         return 0;
 791 }
 792
 793 static int add_object_entry(const unsigned char *sha1, enum object_type type,
 794                             const char *name, int exclude)
 795 {
 796         struct object_entry *entry;
 797         struct packed_git *p, *found_pack = NULL;
 798         off_t found_offset = 0;
 799         int ix;
 800         unsigned hash = name_hash(name);
 801
 802         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
 803         if (ix >= 0) {
 804                 if (exclude) {
 805                         entry = objects + object_ix[ix] - 1;
 806                         if (!entry->preferred_base)
 807                                 nr_result--;
 808                         entry->preferred_base = 1;
 809                 }
 810                 return 0;
 811         }
 812
 813         for (p = packed_git; p; p = p->next) {
 814                 off_t offset = find_pack_entry_one(sha1, p);
 815                 if (offset) {
 816                         if (!found_pack) {
 817                                 found_offset = offset;
 818                                 found_pack = p;
 819                         }
 820                         if (exclude)
 821                                 break;
 822                         if (incremental)
 823                                 return 0;
 824                         if (local && !p->pack_local)
 825                                 return 0;
 826                 }
 827         }
 828
 829         if (nr_objects >= nr_alloc) {
 830                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
 831                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
 832         }
 833
 834         entry = objects + nr_objects++;
 835         memset(entry, 0, sizeof(*entry));
 836         hashcpy(entry->idx.sha1, sha1);
 837         entry->hash = hash;
 838         if (type)
 839                 entry->type = type;
 840         if (exclude)
 841                 entry->preferred_base = 1;
 842         else
 843                 nr_result++;
 844         if (found_pack) {
 845                 entry->in_pack = found_pack;
 846                 entry->in_pack_offset = found_offset;
 847         }
 848
 849         if (object_ix_hashsz * 3 <= nr_objects * 4)
 850                 rehash_objects();
 851         else
 852                 object_ix[-1 - ix] = nr_objects;
 853
 854         display_progress(progress_state, nr_objects);
 855
 856         if (name && no_try_delta(name))
 857                 entry->no_try_delta = 1;
 858
 859         return 1;
 860 }
 861
 862 struct pbase_tree_cache {
 863         unsigned char sha1[20];
 864         int ref;
 865         int temporary;
 866         void *tree_data;
 867         unsigned long tree_size;
 868 };
 869
 870 static struct pbase_tree_cache *(pbase_tree_cache[256]);
 871 static int pbase_tree_cache_ix(const unsigned char *sha1)
 872 {
 873         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 874 }
 875 static int pbase_tree_cache_ix_incr(int ix)
 876 {
 877         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 878 }
 879
 880 static struct pbase_tree {
 881         struct pbase_tree *next;
 882         /* This is a phony "cache" entry; we are not
 883          * going to evict it nor find it through _get()
 884          * mechanism -- this is for the toplevel node that
 885          * would almost always change with any commit.
 886          */
 887         struct pbase_tree_cache pcache;
 888 } *pbase_tree;
 889
 890 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 891 {
 892         struct pbase_tree_cache *ent, *nent;
 893         void *data;
 894         unsigned long size;
 895         enum object_type type;
 896         int neigh;
 897         int my_ix = pbase_tree_cache_ix(sha1);
 898         int available_ix = -1;
 899
 900         /* pbase-tree-cache acts as a limited hashtable.
 901          * your object will be found at your index or within a few
 902          * slots after that slot if it is cached.
 903          */
 904         for (neigh = 0; neigh < 8; neigh++) {
 905                 ent = pbase_tree_cache[my_ix];
 906                 if (ent && !hashcmp(ent->sha1, sha1)) {
 907                         ent->ref++;
 908                         return ent;
 909                 }
 910                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 911                          ((0 <= available_ix) &&
 912                           (!ent && pbase_tree_cache[available_ix])))
 913                         available_ix = my_ix;
 914                 if (!ent)
 915                         break;
 916                 my_ix = pbase_tree_cache_ix_incr(my_ix);
 917         }
 918
 919         /* Did not find one.  Either we got a bogus request or
 920          * we need to read and perhaps cache.
 921          */
 922         data = read_sha1_file(sha1, &type, &size);
 923         if (!data)
 924                 return NULL;
 925         if (type != OBJ_TREE) {
 926                 free(data);
 927                 return NULL;
 928         }
 929
 930         /* We need to either cache or return a throwaway copy */
 931
 932         if (available_ix < 0)
 933                 ent = NULL;
 934         else {
 935                 ent = pbase_tree_cache[available_ix];
 936                 my_ix = available_ix;
 937         }
 938
 939         if (!ent) {
 940                 nent = xmalloc(sizeof(*nent));
 941                 nent->temporary = (available_ix < 0);
 942         }
 943         else {
 944                 /* evict and reuse */
 945                 free(ent->tree_data);
 946                 nent = ent;
 947         }
 948         hashcpy(nent->sha1, sha1);
 949         nent->tree_data = data;
 950         nent->tree_size = size;
 951         nent->ref = 1;
 952         if (!nent->temporary)
 953                 pbase_tree_cache[my_ix] = nent;
 954         return nent;
 955 }
 956
 957 static void pbase_tree_put(struct pbase_tree_cache *cache)
 958 {
 959         if (!cache->temporary) {
 960                 cache->ref--;
 961                 return;
 962         }
 963         free(cache->tree_data);
 964         free(cache);
 965 }
 966
 967 static int name_cmp_len(const char *name)
 968 {
 969         int i;
 970         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 971                 ;
 972         return i;
 973 }
 974
 975 static void add_pbase_object(struct tree_desc *tree,
 976                              const char *name,
 977                              int cmplen,
 978                              const char *fullname)
 979 {
 980         struct name_entry entry;
 981         int cmp;
 982
 983         while (tree_entry(tree,&entry)) {
 984                 if (S_ISGITLINK(entry.mode))
 985                         continue;
 986                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
 987                       memcmp(name, entry.path, cmplen);
 988                 if (cmp > 0)
 989                         continue;
 990                 if (cmp < 0)
 991                         return;
 992                 if (name[cmplen] != '/') {
 993                         add_object_entry(entry.sha1,
 994                                          object_type(entry.mode),
 995                                          fullname, 1);
 996                         return;
 997                 }
 998                 if (S_ISDIR(entry.mode)) {
 999                         struct tree_desc sub;
1000                         struct pbase_tree_cache *tree;
1001                         const char *down = name+cmplen+1;
1002                         int downlen = name_cmp_len(down);
1003
1004                         tree = pbase_tree_get(entry.sha1);
1005                         if (!tree)
1006                                 return;
1007                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1008
1009                         add_pbase_object(&sub, down, downlen, fullname);
1010                         pbase_tree_put(tree);
1011                 }
1012         }
1013 }
1014
1015 static unsigned *done_pbase_paths;
1016 static int done_pbase_paths_num;
1017 static int done_pbase_paths_alloc;
1018 static int done_pbase_path_pos(unsigned hash)
1019 {
1020         int lo = 0;
1021         int hi = done_pbase_paths_num;
1022         while (lo < hi) {
1023                 int mi = (hi + lo) / 2;
1024                 if (done_pbase_paths[mi] == hash)
1025                         return mi;
1026                 if (done_pbase_paths[mi] < hash)
1027                         hi = mi;
1028                 else
1029                         lo = mi + 1;
1030         }
1031         return -lo-1;
1032 }
1033
1034 static int check_pbase_path(unsigned hash)
1035 {
1036         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
1037         if (0 <= pos)
1038                 return 1;
1039         pos = -pos - 1;
1040         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
1041                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
1042                 done_pbase_paths = xrealloc(done_pbase_paths,
1043                                             done_pbase_paths_alloc *
1044                                             sizeof(unsigned));
1045         }
1046         done_pbase_paths_num++;
1047         if (pos < done_pbase_paths_num)
1048                 memmove(done_pbase_paths + pos + 1,
1049                         done_pbase_paths + pos,
1050                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
1051         done_pbase_paths[pos] = hash;
1052         return 0;
1053 }
1054
1055 static void add_preferred_base_object(const char *name)
1056 {
1057         struct pbase_tree *it;
1058         int cmplen;
1059         unsigned hash = name_hash(name);
1060
1061         if (!num_preferred_base || check_pbase_path(hash))
1062                 return;
1063
1064         cmplen = name_cmp_len(name);
1065         for (it = pbase_tree; it; it = it->next) {
1066                 if (cmplen == 0) {
1067                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
1068                 }
1069                 else {
1070                         struct tree_desc tree;
1071                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1072                         add_pbase_object(&tree, name, cmplen, name);
1073                 }
1074         }
1075 }
1076
1077 static void add_preferred_base(unsigned char *sha1)
1078 {
1079         struct pbase_tree *it;
1080         void *data;
1081         unsigned long size;
1082         unsigned char tree_sha1[20];
1083
1084         if (window <= num_preferred_base++)
1085                 return;
1086
1087         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
1088         if (!data)
1089                 return;
1090
1091         for (it = pbase_tree; it; it = it->next) {
1092                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
1093                         free(data);
1094                         return;
1095                 }
1096         }
1097
1098         it = xcalloc(1, sizeof(*it));
1099         it->next = pbase_tree;
1100         pbase_tree = it;
1101
1102         hashcpy(it->pcache.sha1, tree_sha1);
1103         it->pcache.tree_data = data;
1104         it->pcache.tree_size = size;
1105 }
1106
1107 static void check_object(struct object_entry *entry)
1108 {
1109         if (entry->in_pack) {
1110                 struct packed_git *p = entry->in_pack;
1111                 struct pack_window *w_curs = NULL;
1112                 const unsigned char *base_ref = NULL;
1113                 struct object_entry *base_entry;
1114                 unsigned long used, used_0;
1115                 unsigned int avail;
1116                 off_t ofs;
1117                 unsigned char *buf, c;
1118
1119                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1120
1121                 /*
1122                  * We want in_pack_type even if we do not reuse delta
1123                  * since non-delta representations could still be reused.
1124                  */
1125                 used = unpack_object_header_gently(buf, avail,
1126                                                    &entry->in_pack_type,
1127                                                    &entry->size);
1128
1129                 /*
1130                  * Determine if this is a delta and if so whether we can
1131                  * reuse it or not.  Otherwise let's find out as cheaply as
1132                  * possible what the actual type and size for this object is.
1133                  */
1134                 switch (entry->in_pack_type) {
1135                 default:
1136                         /* Not a delta hence we've already got all we need. */
1137                         entry->type = entry->in_pack_type;
1138                         entry->in_pack_header_size = used;
1139                         unuse_pack(&w_curs);
1140                         return;
1141                 case OBJ_REF_DELTA:
1142                         if (!no_reuse_delta && !entry->preferred_base)
1143                                 base_ref = use_pack(p, &w_curs,
1144                                                 entry->in_pack_offset + used, NULL);
1145                         entry->in_pack_header_size = used + 20;
1146                         break;
1147                 case OBJ_OFS_DELTA:
1148                         buf = use_pack(p, &w_curs,
1149                                        entry->in_pack_offset + used, NULL);
1150                         used_0 = 0;
1151                         c = buf[used_0++];
1152                         ofs = c & 127;
1153                         while (c & 128) {
1154                                 ofs += 1;
1155                                 if (!ofs || MSB(ofs, 7))
1156                                         die("delta base offset overflow in pack for %s",
1157                                             sha1_to_hex(entry->idx.sha1));
1158                                 c = buf[used_0++];
1159                                 ofs = (ofs << 7) + (c & 127);
1160                         }
1161                         if (ofs >= entry->in_pack_offset)
1162                                 die("delta base offset out of bound for %s",
1163                                     sha1_to_hex(entry->idx.sha1));
1164                         ofs = entry->in_pack_offset - ofs;
1165                         if (!no_reuse_delta && !entry->preferred_base)
1166                                 base_ref = find_packed_object_name(p, ofs);
1167                         entry->in_pack_header_size = used + used_0;
1168                         break;
1169                 }
1170
1171                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1172                         /*
1173                          * If base_ref was set above that means we wish to
1174                          * reuse delta data, and we even found that base
1175                          * in the list of objects we want to pack. Goodie!
1176                          *
1177                          * Depth value does not matter - find_deltas() will
1178                          * never consider reused delta as the base object to
1179                          * deltify other objects against, in order to avoid
1180                          * circular deltas.
1181                          */
1182                         entry->type = entry->in_pack_type;
1183                         entry->delta = base_entry;
1184                         entry->delta_sibling = base_entry->delta_child;
1185                         base_entry->delta_child = entry;
1186                         unuse_pack(&w_curs);
1187                         return;
1188                 }
1189
1190                 if (entry->type) {
1191                         /*
1192                          * This must be a delta and we already know what the
1193                          * final object type is.  Let's extract the actual
1194                          * object size from the delta header.
1195                          */
1196                         entry->size = get_size_from_delta(p, &w_curs,
1197                                         entry->in_pack_offset + entry->in_pack_header_size);
1198                         unuse_pack(&w_curs);
1199                         return;
1200                 }
1201
1202                 /*
1203                  * No choice but to fall back to the recursive delta walk
1204                  * with sha1_object_info() to find about the object type
1205                  * at this point...
1206                  */
1207                 unuse_pack(&w_curs);
1208         }
1209
1210         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1211         if (entry->type < 0)
1212                 die("unable to get type of object %s",
1213                     sha1_to_hex(entry->idx.sha1));
1214 }
1215
1216 static int pack_offset_sort(const void *_a, const void *_b)
1217 {
1218         const struct object_entry *a = *(struct object_entry **)_a;
1219         const struct object_entry *b = *(struct object_entry **)_b;
1220
1221         /* avoid filesystem trashing with loose objects */
1222         if (!a->in_pack && !b->in_pack)
1223                 return hashcmp(a->idx.sha1, b->idx.sha1);
1224
1225         if (a->in_pack < b->in_pack)
1226                 return -1;
1227         if (a->in_pack > b->in_pack)
1228                 return 1;
1229         return a->in_pack_offset < b->in_pack_offset ? -1 :
1230                         (a->in_pack_offset > b->in_pack_offset);
1231 }
1232
1233 static void get_object_details(void)
1234 {
1235         uint32_t i;
1236         struct object_entry **sorted_by_offset;
1237
1238         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1239         for (i = 0; i < nr_objects; i++)
1240                 sorted_by_offset[i] = objects + i;
1241         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1242
1243         prepare_pack_ix();
1244         for (i = 0; i < nr_objects; i++)
1245                 check_object(sorted_by_offset[i]);
1246         free(sorted_by_offset);
1247 }
1248
1249 /*
1250  * We search for deltas in a list sorted by type, by filename hash, and then
1251  * by size, so that we see progressively smaller and smaller files.
1252  * That's because we prefer deltas to be from the bigger file
1253  * to the smaller -- deletes are potentially cheaper, but perhaps
1254  * more importantly, the bigger file is likely the more recent
1255  * one.  The deepest deltas are therefore the oldest objects which are
1256  * less susceptible to be accessed often.
1257  */
1258 static int type_size_sort(const void *_a, const void *_b)
1259 {
1260         const struct object_entry *a = *(struct object_entry **)_a;
1261         const struct object_entry *b = *(struct object_entry **)_b;
1262
1263         if (a->type > b->type)
1264                 return -1;
1265         if (a->type < b->type)
1266                 return 1;
1267         if (a->hash > b->hash)
1268                 return -1;
1269         if (a->hash < b->hash)
1270                 return 1;
1271         if (a->preferred_base > b->preferred_base)
1272                 return -1;
1273         if (a->preferred_base < b->preferred_base)
1274                 return 1;
1275         if (a->size > b->size)
1276                 return -1;
1277         if (a->size < b->size)
1278                 return 1;
1279         return a < b ? -1 : (a > b);  /* newest first */
1280 }
1281
1282 struct unpacked {
1283         struct object_entry *entry;
1284         void *data;
1285         struct delta_index *index;
1286         unsigned depth;
1287 };
1288
1289 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1290                            unsigned long delta_size)
1291 {
1292         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1293                 return 0;
1294
1295         if (delta_size < cache_max_small_delta_size)
1296                 return 1;
1297
1298         /* cache delta, if objects are large enough compared to delta size */
1299         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1300                 return 1;
1301
1302         return 0;
1303 }
1304
1305 #ifdef THREADED_DELTA_SEARCH
1306
1307 static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
1308 #define read_lock()             pthread_mutex_lock(&read_mutex)
1309 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1310
1311 static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
1312 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1313 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1314
1315 static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
1316 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1317 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1318
1319 #else
1320
1321 #define read_lock()             (void)0
1322 #define read_unlock()           (void)0
1323 #define cache_lock()            (void)0
1324 #define cache_unlock()          (void)0
1325 #define progress_lock()         (void)0
1326 #define progress_unlock()       (void)0
1327
1328 #endif
1329
1330 static int try_delta(struct unpacked *trg, struct unpacked *src,
1331                      unsigned max_depth, unsigned long *mem_usage)
1332 {
1333         struct object_entry *trg_entry = trg->entry;
1334         struct object_entry *src_entry = src->entry;
1335         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1336         unsigned ref_depth;
1337         enum object_type type;
1338         void *delta_buf;
1339
1340         /* Don't bother doing diffs between different types */
1341         if (trg_entry->type != src_entry->type)
1342                 return -1;
1343
1344         /*
1345          * We do not bother to try a delta that we discarded
1346          * on an earlier try, but only when reusing delta data.
1347          */
1348         if (!no_reuse_delta && trg_entry->in_pack &&
1349             trg_entry->in_pack == src_entry->in_pack &&
1350             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1351             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1352                 return 0;
1353
1354         /* Let's not bust the allowed depth. */
1355         if (src->depth >= max_depth)
1356                 return 0;
1357
1358         /* Now some size filtering heuristics. */
1359         trg_size = trg_entry->size;
1360         if (!trg_entry->delta) {
1361                 max_size = trg_size/2 - 20;
1362                 ref_depth = 1;
1363         } else {
1364                 max_size = trg_entry->delta_size;
1365                 ref_depth = trg->depth;
1366         }
1367         max_size = max_size * (max_depth - src->depth) /
1368                                                 (max_depth - ref_depth + 1);
1369         if (max_size == 0)
1370                 return 0;
1371         src_size = src_entry->size;
1372         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1373         if (sizediff >= max_size)
1374                 return 0;
1375         if (trg_size < src_size / 32)
1376                 return 0;
1377
1378         /* Load data if not already done */
1379         if (!trg->data) {
1380                 read_lock();
1381                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1382                 read_unlock();
1383                 if (!trg->data)
1384                         die("object %s cannot be read",
1385                             sha1_to_hex(trg_entry->idx.sha1));
1386                 if (sz != trg_size)
1387                         die("object %s inconsistent object length (%lu vs %lu)",
1388                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1389                 *mem_usage += sz;
1390         }
1391         if (!src->data) {
1392                 read_lock();
1393                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1394                 read_unlock();
1395                 if (!src->data)
1396                         die("object %s cannot be read",
1397                             sha1_to_hex(src_entry->idx.sha1));
1398                 if (sz != src_size)
1399                         die("object %s inconsistent object length (%lu vs %lu)",
1400                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1401                 *mem_usage += sz;
1402         }
1403         if (!src->index) {
1404                 src->index = create_delta_index(src->data, src_size);
1405                 if (!src->index) {
1406                         static int warned = 0;
1407                         if (!warned++)
1408                                 warning("suboptimal pack - out of memory");
1409                         return 0;
1410                 }
1411                 *mem_usage += sizeof_delta_index(src->index);
1412         }
1413
1414         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1415         if (!delta_buf)
1416                 return 0;
1417
1418         if (trg_entry->delta) {
1419                 /* Prefer only shallower same-sized deltas. */
1420                 if (delta_size == trg_entry->delta_size &&
1421                     src->depth + 1 >= trg->depth) {
1422                         free(delta_buf);
1423                         return 0;
1424                 }
1425         }
1426
1427         /*
1428          * Handle memory allocation outside of the cache
1429          * accounting lock.  Compiler will optimize the strangeness
1430          * away when THREADED_DELTA_SEARCH is not defined.
1431          */
1432         free(trg_entry->delta_data);
1433         cache_lock();
1434         if (trg_entry->delta_data) {
1435                 delta_cache_size -= trg_entry->delta_size;
1436                 trg_entry->delta_data = NULL;
1437         }
1438         if (delta_cacheable(src_size, trg_size, delta_size)) {
1439                 delta_cache_size += delta_size;
1440                 cache_unlock();
1441                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1442         } else {
1443                 cache_unlock();
1444                 free(delta_buf);
1445         }
1446
1447         trg_entry->delta = src_entry;
1448         trg_entry->delta_size = delta_size;
1449         trg->depth = src->depth + 1;
1450
1451         return 1;
1452 }
1453
1454 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1455 {
1456         struct object_entry *child = me->delta_child;
1457         unsigned int m = n;
1458         while (child) {
1459                 unsigned int c = check_delta_limit(child, n + 1);
1460                 if (m < c)
1461                         m = c;
1462                 child = child->delta_sibling;
1463         }
1464         return m;
1465 }
1466
1467 static unsigned long free_unpacked(struct unpacked *n)
1468 {
1469         unsigned long freed_mem = sizeof_delta_index(n->index);
1470         free_delta_index(n->index);
1471         n->index = NULL;
1472         if (n->data) {
1473                 freed_mem += n->entry->size;
1474                 free(n->data);
1475                 n->data = NULL;
1476         }
1477         n->entry = NULL;
1478         n->depth = 0;
1479         return freed_mem;
1480 }
1481
1482 static void find_deltas(struct object_entry **list, unsigned *list_size,
1483                         int window, int depth, unsigned *processed)
1484 {
1485         uint32_t i, idx = 0, count = 0;
1486         unsigned int array_size = window * sizeof(struct unpacked);
1487         struct unpacked *array;
1488         unsigned long mem_usage = 0;
1489
1490         array = xmalloc(array_size);
1491         memset(array, 0, array_size);
1492
1493         for (;;) {
1494                 struct object_entry *entry = *list++;
1495                 struct unpacked *n = array + idx;
1496                 int j, max_depth, best_base = -1;
1497
1498                 progress_lock();
1499                 if (!*list_size) {
1500                         progress_unlock();
1501                         break;
1502                 }
1503                 (*list_size)--;
1504                 if (!entry->preferred_base) {
1505                         (*processed)++;
1506                         display_progress(progress_state, *processed);
1507                 }
1508                 progress_unlock();
1509
1510                 mem_usage -= free_unpacked(n);
1511                 n->entry = entry;
1512
1513                 while (window_memory_limit &&
1514                        mem_usage > window_memory_limit &&
1515                        count > 1) {
1516                         uint32_t tail = (idx + window - count) % window;
1517                         mem_usage -= free_unpacked(array + tail);
1518                         count--;
1519                 }
1520
1521                 /* We do not compute delta to *create* objects we are not
1522                  * going to pack.
1523                  */
1524                 if (entry->preferred_base)
1525                         goto next;
1526
1527                 /*
1528                  * If the current object is at pack edge, take the depth the
1529                  * objects that depend on the current object into account
1530                  * otherwise they would become too deep.
1531                  */
1532                 max_depth = depth;
1533                 if (entry->delta_child) {
1534                         max_depth -= check_delta_limit(entry, 0);
1535                         if (max_depth <= 0)
1536                                 goto next;
1537                 }
1538
1539                 j = window;
1540                 while (--j > 0) {
1541                         int ret;
1542                         uint32_t other_idx = idx + j;
1543                         struct unpacked *m;
1544                         if (other_idx >= window)
1545                                 other_idx -= window;
1546                         m = array + other_idx;
1547                         if (!m->entry)
1548                                 break;
1549                         ret = try_delta(n, m, max_depth, &mem_usage);
1550                         if (ret < 0)
1551                                 break;
1552                         else if (ret > 0)
1553                                 best_base = other_idx;
1554                 }
1555
1556                 /* if we made n a delta, and if n is already at max
1557                  * depth, leaving it in the window is pointless.  we
1558                  * should evict it first.
1559                  */
1560                 if (entry->delta && depth <= n->depth)
1561                         continue;
1562
1563                 /*
1564                  * Move the best delta base up in the window, after the
1565                  * currently deltified object, to keep it longer.  It will
1566                  * be the first base object to be attempted next.
1567                  */
1568                 if (entry->delta) {
1569                         struct unpacked swap = array[best_base];
1570                         int dist = (window + idx - best_base) % window;
1571                         int dst = best_base;
1572                         while (dist--) {
1573                                 int src = (dst + 1) % window;
1574                                 array[dst] = array[src];
1575                                 dst = src;
1576                         }
1577                         array[dst] = swap;
1578                 }
1579
1580                 next:
1581                 idx++;
1582                 if (count + 1 < window)
1583                         count++;
1584                 if (idx >= window)
1585                         idx = 0;
1586         }
1587
1588         for (i = 0; i < window; ++i) {
1589                 free_delta_index(array[i].index);
1590                 free(array[i].data);
1591         }
1592         free(array);
1593 }
1594
1595 #ifdef THREADED_DELTA_SEARCH
1596
1597 /*
1598  * The main thread waits on the condition that (at least) one of the workers
1599  * has stopped working (which is indicated in the .working member of
1600  * struct thread_params).
1601  * When a work thread has completed its work, it sets .working to 0 and
1602  * signals the main thread and waits on the condition that .data_ready
1603  * becomes 1.
1604  */
1605
1606 struct thread_params {
1607         pthread_t thread;
1608         struct object_entry **list;
1609         unsigned list_size;
1610         unsigned remaining;
1611         int window;
1612         int depth;
1613         int working;
1614         int data_ready;
1615         pthread_mutex_t mutex;
1616         pthread_cond_t cond;
1617         unsigned *processed;
1618 };
1619
1620 static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
1621
1622 static void *threaded_find_deltas(void *arg)
1623 {
1624         struct thread_params *me = arg;
1625
1626         while (me->remaining) {
1627                 find_deltas(me->list, &me->remaining,
1628                             me->window, me->depth, me->processed);
1629
1630                 progress_lock();
1631                 me->working = 0;
1632                 pthread_cond_signal(&progress_cond);
1633                 progress_unlock();
1634
1635                 /*
1636                  * We must not set ->data_ready before we wait on the
1637                  * condition because the main thread may have set it to 1
1638                  * before we get here. In order to be sure that new
1639                  * work is available if we see 1 in ->data_ready, it
1640                  * was initialized to 0 before this thread was spawned
1641                  * and we reset it to 0 right away.
1642                  */
1643                 pthread_mutex_lock(&me->mutex);
1644                 while (!me->data_ready)
1645                         pthread_cond_wait(&me->cond, &me->mutex);
1646                 me->data_ready = 0;
1647                 pthread_mutex_unlock(&me->mutex);
1648         }
1649         /* leave ->working 1 so that this doesn't get more work assigned */
1650         return NULL;
1651 }
1652
1653 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1654                            int window, int depth, unsigned *processed)
1655 {
1656         struct thread_params p[delta_search_threads];
1657         int i, ret, active_threads = 0;
1658
1659         if (delta_search_threads <= 1) {
1660                 find_deltas(list, &list_size, window, depth, processed);
1661                 return;
1662         }
1663
1664         /* Partition the work amongst work threads. */
1665         for (i = 0; i < delta_search_threads; i++) {
1666                 unsigned sub_size = list_size / (delta_search_threads - i);
1667
1668                 p[i].window = window;
1669                 p[i].depth = depth;
1670                 p[i].processed = processed;
1671                 p[i].working = 1;
1672                 p[i].data_ready = 0;
1673
1674                 /* try to split chunks on "path" boundaries */
1675                 while (sub_size && sub_size < list_size &&
1676                        list[sub_size]->hash &&
1677                        list[sub_size]->hash == list[sub_size-1]->hash)
1678                         sub_size++;
1679
1680                 p[i].list = list;
1681                 p[i].list_size = sub_size;
1682                 p[i].remaining = sub_size;
1683
1684                 list += sub_size;
1685                 list_size -= sub_size;
1686         }
1687
1688         /* Start work threads. */
1689         for (i = 0; i < delta_search_threads; i++) {
1690                 if (!p[i].list_size)
1691                         continue;
1692                 pthread_mutex_init(&p[i].mutex, NULL);
1693                 pthread_cond_init(&p[i].cond, NULL);
1694                 ret = pthread_create(&p[i].thread, NULL,
1695                                      threaded_find_deltas, &p[i]);
1696                 if (ret)
1697                         die("unable to create thread: %s", strerror(ret));
1698                 active_threads++;
1699         }
1700
1701         /*
1702          * Now let's wait for work completion.  Each time a thread is done
1703          * with its work, we steal half of the remaining work from the
1704          * thread with the largest number of unprocessed objects and give
1705          * it to that newly idle thread.  This ensure good load balancing
1706          * until the remaining object list segments are simply too short
1707          * to be worth splitting anymore.
1708          */
1709         while (active_threads) {
1710                 struct thread_params *target = NULL;
1711                 struct thread_params *victim = NULL;
1712                 unsigned sub_size = 0;
1713
1714                 progress_lock();
1715                 for (;;) {
1716                         for (i = 0; !target && i < delta_search_threads; i++)
1717                                 if (!p[i].working)
1718                                         target = &p[i];
1719                         if (target)
1720                                 break;
1721                         pthread_cond_wait(&progress_cond, &progress_mutex);
1722                 }
1723
1724                 for (i = 0; i < delta_search_threads; i++)
1725                         if (p[i].remaining > 2*window &&
1726                             (!victim || victim->remaining < p[i].remaining))
1727                                 victim = &p[i];
1728                 if (victim) {
1729                         sub_size = victim->remaining / 2;
1730                         list = victim->list + victim->list_size - sub_size;
1731                         while (sub_size && list[0]->hash &&
1732                                list[0]->hash == list[-1]->hash) {
1733                                 list++;
1734                                 sub_size--;
1735                         }
1736                         if (!sub_size) {
1737                                 /*
1738                                  * It is possible for some "paths" to have
1739                                  * so many objects that no hash boundary
1740                                  * might be found.  Let's just steal the
1741                                  * exact half in that case.
1742                                  */
1743                                 sub_size = victim->remaining / 2;
1744                                 list -= sub_size;
1745                         }
1746                         target->list = list;
1747                         victim->list_size -= sub_size;
1748                         victim->remaining -= sub_size;
1749                 }
1750                 target->list_size = sub_size;
1751                 target->remaining = sub_size;
1752                 target->working = 1;
1753                 progress_unlock();
1754
1755                 pthread_mutex_lock(&target->mutex);
1756                 target->data_ready = 1;
1757                 pthread_cond_signal(&target->cond);
1758                 pthread_mutex_unlock(&target->mutex);
1759
1760                 if (!sub_size) {
1761                         pthread_join(target->thread, NULL);
1762                         pthread_cond_destroy(&target->cond);
1763                         pthread_mutex_destroy(&target->mutex);
1764                         active_threads--;
1765                 }
1766         }
1767 }
1768
1769 #else
1770 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
1771 #endif
1772
1773 static void prepare_pack(int window, int depth)
1774 {
1775         struct object_entry **delta_list;
1776         uint32_t i, n, nr_deltas;
1777
1778         get_object_details();
1779
1780         if (!nr_objects || !window || !depth)
1781                 return;
1782
1783         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1784         nr_deltas = n = 0;
1785
1786         for (i = 0; i < nr_objects; i++) {
1787                 struct object_entry *entry = objects + i;
1788
1789                 if (entry->delta)
1790                         /* This happens if we decided to reuse existing
1791                          * delta from a pack.  "!no_reuse_delta &&" is implied.
1792                          */
1793                         continue;
1794
1795                 if (entry->size < 50)
1796                         continue;
1797
1798                 if (entry->no_try_delta)
1799                         continue;
1800
1801                 if (!entry->preferred_base)
1802                         nr_deltas++;
1803
1804                 delta_list[n++] = entry;
1805         }
1806
1807         if (nr_deltas && n > 1) {
1808                 unsigned nr_done = 0;
1809                 if (progress)
1810                         progress_state = start_progress("Compressing objects",
1811                                                         nr_deltas);
1812                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
1813                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
1814                 stop_progress(&progress_state);
1815                 if (nr_done != nr_deltas)
1816                         die("inconsistency with delta count");
1817         }
1818         free(delta_list);
1819 }
1820
1821 static int git_pack_config(const char *k, const char *v)
1822 {
1823         if(!strcmp(k, "pack.window")) {
1824                 window = git_config_int(k, v);
1825                 return 0;
1826         }
1827         if (!strcmp(k, "pack.windowmemory")) {
1828                 window_memory_limit = git_config_ulong(k, v);
1829                 return 0;
1830         }
1831         if (!strcmp(k, "pack.depth")) {
1832                 depth = git_config_int(k, v);
1833                 return 0;
1834         }
1835         if (!strcmp(k, "pack.compression")) {
1836                 int level = git_config_int(k, v);
1837                 if (level == -1)
1838                         level = Z_DEFAULT_COMPRESSION;
1839                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1840                         die("bad pack compression level %d", level);
1841                 pack_compression_level = level;
1842                 pack_compression_seen = 1;
1843                 return 0;
1844         }
1845         if (!strcmp(k, "pack.deltacachesize")) {
1846                 max_delta_cache_size = git_config_int(k, v);
1847                 return 0;
1848         }
1849         if (!strcmp(k, "pack.deltacachelimit")) {
1850                 cache_max_small_delta_size = git_config_int(k, v);
1851                 return 0;
1852         }
1853         if (!strcmp(k, "pack.threads")) {
1854                 delta_search_threads = git_config_int(k, v);
1855                 if (delta_search_threads < 0)
1856                         die("invalid number of threads specified (%d)",
1857                             delta_search_threads);
1858 #ifndef THREADED_DELTA_SEARCH
1859                 if (delta_search_threads != 1)
1860                         warning("no threads support, ignoring %s", k);
1861 #endif
1862                 return 0;
1863         }
1864         if (!strcmp(k, "pack.indexversion")) {
1865                 pack_idx_default_version = git_config_int(k, v);
1866                 if (pack_idx_default_version > 2)
1867                         die("bad pack.indexversion=%d", pack_idx_default_version);
1868                 return 0;
1869         }
1870         if (!strcmp(k, "pack.packsizelimit")) {
1871                 pack_size_limit_cfg = git_config_ulong(k, v);
1872                 return 0;
1873         }
1874         return git_default_config(k, v);
1875 }
1876
1877 static void read_object_list_from_stdin(void)
1878 {
1879         char line[40 + 1 + PATH_MAX + 2];
1880         unsigned char sha1[20];
1881
1882         for (;;) {
1883                 if (!fgets(line, sizeof(line), stdin)) {
1884                         if (feof(stdin))
1885                                 break;
1886                         if (!ferror(stdin))
1887                                 die("fgets returned NULL, not EOF, not error!");
1888                         if (errno != EINTR)
1889                                 die("fgets: %s", strerror(errno));
1890                         clearerr(stdin);
1891                         continue;
1892                 }
1893                 if (line[0] == '-') {
1894                         if (get_sha1_hex(line+1, sha1))
1895                                 die("expected edge sha1, got garbage:\n %s",
1896                                     line);
1897                         add_preferred_base(sha1);
1898                         continue;
1899                 }
1900                 if (get_sha1_hex(line, sha1))
1901                         die("expected sha1, got garbage:\n %s", line);
1902
1903                 add_preferred_base_object(line+41);
1904                 add_object_entry(sha1, 0, line+41, 0);
1905         }
1906 }
1907
1908 #define OBJECT_ADDED (1u<<20)
1909
1910 static void show_commit(struct commit *commit)
1911 {
1912         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
1913         commit->object.flags |= OBJECT_ADDED;
1914 }
1915
1916 static void show_object(struct object_array_entry *p)
1917 {
1918         add_preferred_base_object(p->name);
1919         add_object_entry(p->item->sha1, p->item->type, p->name, 0);
1920         p->item->flags |= OBJECT_ADDED;
1921 }
1922
1923 static void show_edge(struct commit *commit)
1924 {
1925         add_preferred_base(commit->object.sha1);
1926 }
1927
1928 struct in_pack_object {
1929         off_t offset;
1930         struct object *object;
1931 };
1932
1933 struct in_pack {
1934         int alloc;
1935         int nr;
1936         struct in_pack_object *array;
1937 };
1938
1939 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
1940 {
1941         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
1942         in_pack->array[in_pack->nr].object = object;
1943         in_pack->nr++;
1944 }
1945
1946 /*
1947  * Compare the objects in the offset order, in order to emulate the
1948  * "git-rev-list --objects" output that produced the pack originally.
1949  */
1950 static int ofscmp(const void *a_, const void *b_)
1951 {
1952         struct in_pack_object *a = (struct in_pack_object *)a_;
1953         struct in_pack_object *b = (struct in_pack_object *)b_;
1954
1955         if (a->offset < b->offset)
1956                 return -1;
1957         else if (a->offset > b->offset)
1958                 return 1;
1959         else
1960                 return hashcmp(a->object->sha1, b->object->sha1);
1961 }
1962
1963 static void add_objects_in_unpacked_packs(struct rev_info *revs)
1964 {
1965         struct packed_git *p;
1966         struct in_pack in_pack;
1967         uint32_t i;
1968
1969         memset(&in_pack, 0, sizeof(in_pack));
1970
1971         for (p = packed_git; p; p = p->next) {
1972                 const unsigned char *sha1;
1973                 struct object *o;
1974
1975                 for (i = 0; i < revs->num_ignore_packed; i++) {
1976                         if (matches_pack_name(p, revs->ignore_packed[i]))
1977                                 break;
1978                 }
1979                 if (revs->num_ignore_packed <= i)
1980                         continue;
1981                 if (open_pack_index(p))
1982                         die("cannot open pack index");
1983
1984                 ALLOC_GROW(in_pack.array,
1985                            in_pack.nr + p->num_objects,
1986                            in_pack.alloc);
1987
1988                 for (i = 0; i < p->num_objects; i++) {
1989                         sha1 = nth_packed_object_sha1(p, i);
1990                         o = lookup_unknown_object(sha1);
1991                         if (!(o->flags & OBJECT_ADDED))
1992                                 mark_in_pack_object(o, p, &in_pack);
1993                         o->flags |= OBJECT_ADDED;
1994                 }
1995         }
1996
1997         if (in_pack.nr) {
1998                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
1999                       ofscmp);
2000                 for (i = 0; i < in_pack.nr; i++) {
2001                         struct object *o = in_pack.array[i].object;
2002                         add_object_entry(o->sha1, o->type, "", 0);
2003                 }
2004         }
2005         free(in_pack.array);
2006 }
2007
2008 static void get_object_list(int ac, const char **av)
2009 {
2010         struct rev_info revs;
2011         char line[1000];
2012         int flags = 0;
2013
2014         init_revisions(&revs, NULL);
2015         save_commit_buffer = 0;
2016         setup_revisions(ac, av, &revs, NULL);
2017
2018         while (fgets(line, sizeof(line), stdin) != NULL) {
2019                 int len = strlen(line);
2020                 if (len && line[len - 1] == '\n')
2021                         line[--len] = 0;
2022                 if (!len)
2023                         break;
2024                 if (*line == '-') {
2025                         if (!strcmp(line, "--not")) {
2026                                 flags ^= UNINTERESTING;
2027                                 continue;
2028                         }
2029                         die("not a rev '%s'", line);
2030                 }
2031                 if (handle_revision_arg(line, &revs, flags, 1))
2032                         die("bad revision '%s'", line);
2033         }
2034
2035         if (prepare_revision_walk(&revs))
2036                 die("revision walk setup failed");
2037         mark_edges_uninteresting(revs.commits, &revs, show_edge);
2038         traverse_commit_list(&revs, show_commit, show_object);
2039
2040         if (keep_unreachable)
2041                 add_objects_in_unpacked_packs(&revs);
2042 }
2043
2044 static int adjust_perm(const char *path, mode_t mode)
2045 {
2046         if (chmod(path, mode))
2047                 return -1;
2048         return adjust_shared_perm(path);
2049 }
2050
2051 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2052 {
2053         int use_internal_rev_list = 0;
2054         int thin = 0;
2055         uint32_t i;
2056         const char **rp_av;
2057         int rp_ac_alloc = 64;
2058         int rp_ac;
2059
2060         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
2061
2062         rp_av[0] = "pack-objects";
2063         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
2064         rp_ac = 2;
2065
2066         git_config(git_pack_config);
2067         if (!pack_compression_seen && core_compression_seen)
2068                 pack_compression_level = core_compression_level;
2069
2070         progress = isatty(2);
2071         for (i = 1; i < argc; i++) {
2072                 const char *arg = argv[i];
2073
2074                 if (*arg != '-')
2075                         break;
2076
2077                 if (!strcmp("--non-empty", arg)) {
2078                         non_empty = 1;
2079                         continue;
2080                 }
2081                 if (!strcmp("--local", arg)) {
2082                         local = 1;
2083                         continue;
2084                 }
2085                 if (!strcmp("--incremental", arg)) {
2086                         incremental = 1;
2087                         continue;
2088                 }
2089                 if (!prefixcmp(arg, "--compression=")) {
2090                         char *end;
2091                         int level = strtoul(arg+14, &end, 0);
2092                         if (!arg[14] || *end)
2093                                 usage(pack_usage);
2094                         if (level == -1)
2095                                 level = Z_DEFAULT_COMPRESSION;
2096                         else if (level < 0 || level > Z_BEST_COMPRESSION)
2097                                 die("bad pack compression level %d", level);
2098                         pack_compression_level = level;
2099                         continue;
2100                 }
2101                 if (!prefixcmp(arg, "--max-pack-size=")) {
2102                         char *end;
2103                         pack_size_limit_cfg = 0;
2104                         pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
2105                         if (!arg[16] || *end)
2106                                 usage(pack_usage);
2107                         continue;
2108                 }
2109                 if (!prefixcmp(arg, "--window=")) {
2110                         char *end;
2111                         window = strtoul(arg+9, &end, 0);
2112                         if (!arg[9] || *end)
2113                                 usage(pack_usage);
2114                         continue;
2115                 }
2116                 if (!prefixcmp(arg, "--window-memory=")) {
2117                         if (!git_parse_ulong(arg+16, &window_memory_limit))
2118                                 usage(pack_usage);
2119                         continue;
2120                 }
2121                 if (!prefixcmp(arg, "--threads=")) {
2122                         char *end;
2123                         delta_search_threads = strtoul(arg+10, &end, 0);
2124                         if (!arg[10] || *end || delta_search_threads < 0)
2125                                 usage(pack_usage);
2126 #ifndef THREADED_DELTA_SEARCH
2127                         if (delta_search_threads != 1)
2128                                 warning("no threads support, "
2129                                         "ignoring %s", arg);
2130 #endif
2131                         continue;
2132                 }
2133                 if (!prefixcmp(arg, "--depth=")) {
2134                         char *end;
2135                         depth = strtoul(arg+8, &end, 0);
2136                         if (!arg[8] || *end)
2137                                 usage(pack_usage);
2138                         continue;
2139                 }
2140                 if (!strcmp("--progress", arg)) {
2141                         progress = 1;
2142                         continue;
2143                 }
2144                 if (!strcmp("--all-progress", arg)) {
2145                         progress = 2;
2146                         continue;
2147                 }
2148                 if (!strcmp("-q", arg)) {
2149                         progress = 0;
2150                         continue;
2151                 }
2152                 if (!strcmp("--no-reuse-delta", arg)) {
2153                         no_reuse_delta = 1;
2154                         continue;
2155                 }
2156                 if (!strcmp("--no-reuse-object", arg)) {
2157                         no_reuse_object = no_reuse_delta = 1;
2158                         continue;
2159                 }
2160                 if (!strcmp("--delta-base-offset", arg)) {
2161                         allow_ofs_delta = 1;
2162                         continue;
2163                 }
2164                 if (!strcmp("--stdout", arg)) {
2165                         pack_to_stdout = 1;
2166                         continue;
2167                 }
2168                 if (!strcmp("--revs", arg)) {
2169                         use_internal_rev_list = 1;
2170                         continue;
2171                 }
2172                 if (!strcmp("--keep-unreachable", arg)) {
2173                         keep_unreachable = 1;
2174                         continue;
2175                 }
2176                 if (!strcmp("--unpacked", arg) ||
2177                     !prefixcmp(arg, "--unpacked=") ||
2178                     !strcmp("--reflog", arg) ||
2179                     !strcmp("--all", arg)) {
2180                         use_internal_rev_list = 1;
2181                         if (rp_ac >= rp_ac_alloc - 1) {
2182                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
2183                                 rp_av = xrealloc(rp_av,
2184                                                  rp_ac_alloc * sizeof(*rp_av));
2185                         }
2186                         rp_av[rp_ac++] = arg;
2187                         continue;
2188                 }
2189                 if (!strcmp("--thin", arg)) {
2190                         use_internal_rev_list = 1;
2191                         thin = 1;
2192                         rp_av[1] = "--objects-edge";
2193                         continue;
2194                 }
2195                 if (!prefixcmp(arg, "--index-version=")) {
2196                         char *c;
2197                         pack_idx_default_version = strtoul(arg + 16, &c, 10);
2198                         if (pack_idx_default_version > 2)
2199                                 die("bad %s", arg);
2200                         if (*c == ',')
2201                                 pack_idx_off32_limit = strtoul(c+1, &c, 0);
2202                         if (*c || pack_idx_off32_limit & 0x80000000)
2203                                 die("bad %s", arg);
2204                         continue;
2205                 }
2206                 usage(pack_usage);
2207         }
2208
2209         /* Traditionally "pack-objects [options] base extra" failed;
2210          * we would however want to take refs parameter that would
2211          * have been given to upstream rev-list ourselves, which means
2212          * we somehow want to say what the base name is.  So the
2213          * syntax would be:
2214          *
2215          * pack-objects [options] base <refs...>
2216          *
2217          * in other words, we would treat the first non-option as the
2218          * base_name and send everything else to the internal revision
2219          * walker.
2220          */
2221
2222         if (!pack_to_stdout)
2223                 base_name = argv[i++];
2224
2225         if (pack_to_stdout != !base_name)
2226                 usage(pack_usage);
2227
2228         if (!pack_to_stdout && !pack_size_limit)
2229                 pack_size_limit = pack_size_limit_cfg;
2230
2231         if (pack_to_stdout && pack_size_limit)
2232                 die("--max-pack-size cannot be used to build a pack for transfer.");
2233
2234         if (!pack_to_stdout && thin)
2235                 die("--thin cannot be used to build an indexable pack.");
2236
2237 #ifdef THREADED_DELTA_SEARCH
2238         if (!delta_search_threads)      /* --threads=0 means autodetect */
2239                 delta_search_threads = online_cpus();
2240 #endif
2241
2242         prepare_packed_git();
2243
2244         if (progress)
2245                 progress_state = start_progress("Counting objects", 0);
2246         if (!use_internal_rev_list)
2247                 read_object_list_from_stdin();
2248         else {
2249                 rp_av[rp_ac] = NULL;
2250                 get_object_list(rp_ac, rp_av);
2251         }
2252         stop_progress(&progress_state);
2253
2254         if (non_empty && !nr_result)
2255                 return 0;
2256         if (nr_result)
2257                 prepare_pack(window, depth);
2258         write_pack_file();
2259         if (progress)
2260                 fprintf(stderr, "Total %u (delta %u), reused %u (delta %u)\n",
2261                         written, written_delta, reused, reused_delta);
2262         return 0;
2263 }