builtin-pack-objects.con commit Allow arbitrary number of arguments to git-pack-objects (ffa84ff)
   1#include "builtin.h"
   2#include "cache.h"
   3#include "object.h"
   4#include "blob.h"
   5#include "commit.h"
   6#include "tag.h"
   7#include "tree.h"
   8#include "delta.h"
   9#include "pack.h"
  10#include "csum-file.h"
  11#include "tree-walk.h"
  12#include "diff.h"
  13#include "revision.h"
  14#include "list-objects.h"
  15
  16static const char pack_usage[] = "\
  17git-pack-objects [{ -q | --progress | --all-progress }] \n\
  18        [--local] [--incremental] [--window=N] [--depth=N] \n\
  19        [--no-reuse-delta] [--delta-base-offset] [--non-empty] \n\
  20        [--revs [--unpacked | --all]*] [--reflog] [--stdout | base-name] \n\
  21        [<ref-list | <object-list]";
  22
  23struct object_entry {
  24        unsigned char sha1[20];
  25        unsigned long size;     /* uncompressed size */
  26        unsigned long offset;   /* offset into the final pack file;
  27                                 * nonzero if already written.
  28                                 */
  29        unsigned int depth;     /* delta depth */
  30        unsigned int delta_limit;       /* base adjustment for in-pack delta */
  31        unsigned int hash;      /* name hint hash */
  32        enum object_type type;
  33        enum object_type in_pack_type;  /* could be delta */
  34        unsigned long delta_size;       /* delta data size (uncompressed) */
  35#define in_pack_header_size delta_size  /* only when reusing pack data */
  36        struct object_entry *delta;     /* delta base object */
  37        struct packed_git *in_pack;     /* already in pack */
  38        unsigned int in_pack_offset;
  39        struct object_entry *delta_child; /* deltified objects who bases me */
  40        struct object_entry *delta_sibling; /* other deltified objects who
  41                                             * uses the same base as me
  42                                             */
  43        int preferred_base;     /* we do not pack this, but is encouraged to
  44                                 * be used as the base objectto delta huge
  45                                 * objects against.
  46                                 */
  47};
  48
  49/*
  50 * Objects we are going to pack are collected in objects array (dynamically
  51 * expanded).  nr_objects & nr_alloc controls this array.  They are stored
  52 * in the order we see -- typically rev-list --objects order that gives us
  53 * nice "minimum seek" order.
  54 *
  55 * sorted-by-sha ans sorted-by-type are arrays of pointers that point at
  56 * elements in the objects array.  The former is used to build the pack
  57 * index (lists object names in the ascending order to help offset lookup),
  58 * and the latter is used to group similar things together by try_delta()
  59 * heuristics.
  60 */
  61
  62static unsigned char object_list_sha1[20];
  63static int non_empty;
  64static int no_reuse_delta;
  65static int local;
  66static int incremental;
  67static int allow_ofs_delta;
  68
  69static struct object_entry **sorted_by_sha, **sorted_by_type;
  70static struct object_entry *objects;
  71static int nr_objects, nr_alloc, nr_result;
  72static const char *base_name;
  73static unsigned char pack_file_sha1[20];
  74static int progress = 1;
  75static volatile sig_atomic_t progress_update;
  76static int window = 10;
  77static int pack_to_stdout;
  78static int num_preferred_base;
  79
  80/*
  81 * The object names in objects array are hashed with this hashtable,
  82 * to help looking up the entry by object name.  Binary search from
  83 * sorted_by_sha is also possible but this was easier to code and faster.
  84 * This hashtable is built after all the objects are seen.
  85 */
  86static int *object_ix;
  87static int object_ix_hashsz;
  88
  89/*
  90 * Pack index for existing packs give us easy access to the offsets into
  91 * corresponding pack file where each object's data starts, but the entries
  92 * do not store the size of the compressed representation (uncompressed
  93 * size is easily available by examining the pack entry header).  It is
  94 * also rather expensive to find the sha1 for an object given its offset.
  95 *
  96 * We build a hashtable of existing packs (pack_revindex), and keep reverse
  97 * index here -- pack index file is sorted by object name mapping to offset;
  98 * this pack_revindex[].revindex array is a list of offset/index_nr pairs
  99 * ordered by offset, so if you know the offset of an object, next offset
 100 * is where its packed representation ends and the index_nr can be used to
 101 * get the object sha1 from the main index.
 102 */
 103struct revindex_entry {
 104        unsigned int offset;
 105        unsigned int nr;
 106};
 107struct pack_revindex {
 108        struct packed_git *p;
 109        struct revindex_entry *revindex;
 110};
 111static struct  pack_revindex *pack_revindex;
 112static int pack_revindex_hashsz;
 113
 114/*
 115 * stats
 116 */
 117static int written;
 118static int written_delta;
 119static int reused;
 120static int reused_delta;
 121
 122static int pack_revindex_ix(struct packed_git *p)
 123{
 124        unsigned long ui = (unsigned long)p;
 125        int i;
 126
 127        ui = ui ^ (ui >> 16); /* defeat structure alignment */
 128        i = (int)(ui % pack_revindex_hashsz);
 129        while (pack_revindex[i].p) {
 130                if (pack_revindex[i].p == p)
 131                        return i;
 132                if (++i == pack_revindex_hashsz)
 133                        i = 0;
 134        }
 135        return -1 - i;
 136}
 137
 138static void prepare_pack_ix(void)
 139{
 140        int num;
 141        struct packed_git *p;
 142        for (num = 0, p = packed_git; p; p = p->next)
 143                num++;
 144        if (!num)
 145                return;
 146        pack_revindex_hashsz = num * 11;
 147        pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
 148        for (p = packed_git; p; p = p->next) {
 149                num = pack_revindex_ix(p);
 150                num = - 1 - num;
 151                pack_revindex[num].p = p;
 152        }
 153        /* revindex elements are lazily initialized */
 154}
 155
 156static int cmp_offset(const void *a_, const void *b_)
 157{
 158        const struct revindex_entry *a = a_;
 159        const struct revindex_entry *b = b_;
 160        return (a->offset < b->offset) ? -1 : (a->offset > b->offset) ? 1 : 0;
 161}
 162
 163/*
 164 * Ordered list of offsets of objects in the pack.
 165 */
 166static void prepare_pack_revindex(struct pack_revindex *rix)
 167{
 168        struct packed_git *p = rix->p;
 169        int num_ent = num_packed_objects(p);
 170        int i;
 171        void *index = p->index_base + 256;
 172
 173        rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1));
 174        for (i = 0; i < num_ent; i++) {
 175                unsigned int hl = *((unsigned int *)((char *) index + 24*i));
 176                rix->revindex[i].offset = ntohl(hl);
 177                rix->revindex[i].nr = i;
 178        }
 179        /* This knows the pack format -- the 20-byte trailer
 180         * follows immediately after the last object data.
 181         */
 182        rix->revindex[num_ent].offset = p->pack_size - 20;
 183        rix->revindex[num_ent].nr = -1;
 184        qsort(rix->revindex, num_ent, sizeof(*rix->revindex), cmp_offset);
 185}
 186
 187static struct revindex_entry * find_packed_object(struct packed_git *p,
 188                                                  unsigned int ofs)
 189{
 190        int num;
 191        int lo, hi;
 192        struct pack_revindex *rix;
 193        struct revindex_entry *revindex;
 194        num = pack_revindex_ix(p);
 195        if (num < 0)
 196                die("internal error: pack revindex uninitialized");
 197        rix = &pack_revindex[num];
 198        if (!rix->revindex)
 199                prepare_pack_revindex(rix);
 200        revindex = rix->revindex;
 201        lo = 0;
 202        hi = num_packed_objects(p) + 1;
 203        do {
 204                int mi = (lo + hi) / 2;
 205                if (revindex[mi].offset == ofs) {
 206                        return revindex + mi;
 207                }
 208                else if (ofs < revindex[mi].offset)
 209                        hi = mi;
 210                else
 211                        lo = mi + 1;
 212        } while (lo < hi);
 213        die("internal error: pack revindex corrupt");
 214}
 215
 216static unsigned long find_packed_object_size(struct packed_git *p,
 217                                             unsigned long ofs)
 218{
 219        struct revindex_entry *entry = find_packed_object(p, ofs);
 220        return entry[1].offset - ofs;
 221}
 222
 223static unsigned char *find_packed_object_name(struct packed_git *p,
 224                                              unsigned long ofs)
 225{
 226        struct revindex_entry *entry = find_packed_object(p, ofs);
 227        return (unsigned char *)(p->index_base + 256) + 24 * entry->nr + 4;
 228}
 229
 230static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
 231{
 232        unsigned long othersize, delta_size;
 233        char type[10];
 234        void *otherbuf = read_sha1_file(entry->delta->sha1, type, &othersize);
 235        void *delta_buf;
 236
 237        if (!otherbuf)
 238                die("unable to read %s", sha1_to_hex(entry->delta->sha1));
 239        delta_buf = diff_delta(otherbuf, othersize,
 240                               buf, size, &delta_size, 0);
 241        if (!delta_buf || delta_size != entry->delta_size)
 242                die("delta size changed");
 243        free(buf);
 244        free(otherbuf);
 245        return delta_buf;
 246}
 247
 248/*
 249 * The per-object header is a pretty dense thing, which is
 250 *  - first byte: low four bits are "size", then three bits of "type",
 251 *    and the high bit is "size continues".
 252 *  - each byte afterwards: low seven bits are size continuation,
 253 *    with the high bit being "size continues"
 254 */
 255static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
 256{
 257        int n = 1;
 258        unsigned char c;
 259
 260        if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
 261                die("bad type %d", type);
 262
 263        c = (type << 4) | (size & 15);
 264        size >>= 4;
 265        while (size) {
 266                *hdr++ = c | 0x80;
 267                c = size & 0x7f;
 268                size >>= 7;
 269                n++;
 270        }
 271        *hdr = c;
 272        return n;
 273}
 274
 275/*
 276 * we are going to reuse the existing object data as is.  make
 277 * sure it is not corrupt.
 278 */
 279static int check_pack_inflate(struct packed_git *p,
 280                struct pack_window **w_curs,
 281                unsigned long offset,
 282                unsigned long len,
 283                unsigned long expect)
 284{
 285        z_stream stream;
 286        unsigned char fakebuf[4096], *in;
 287        int st;
 288
 289        memset(&stream, 0, sizeof(stream));
 290        inflateInit(&stream);
 291        do {
 292                in = use_pack(p, w_curs, offset, &stream.avail_in);
 293                stream.next_in = in;
 294                stream.next_out = fakebuf;
 295                stream.avail_out = sizeof(fakebuf);
 296                st = inflate(&stream, Z_FINISH);
 297                offset += stream.next_in - in;
 298        } while (st == Z_OK || st == Z_BUF_ERROR);
 299        inflateEnd(&stream);
 300        return (st == Z_STREAM_END &&
 301                stream.total_out == expect &&
 302                stream.total_in == len) ? 0 : -1;
 303}
 304
 305static void copy_pack_data(struct sha1file *f,
 306                struct packed_git *p,
 307                struct pack_window **w_curs,
 308                unsigned long offset,
 309                unsigned long len)
 310{
 311        unsigned char *in;
 312        unsigned int avail;
 313
 314        while (len) {
 315                in = use_pack(p, w_curs, offset, &avail);
 316                if (avail > len)
 317                        avail = len;
 318                sha1write(f, in, avail);
 319                offset += avail;
 320                len -= avail;
 321        }
 322}
 323
 324static int check_loose_inflate(unsigned char *data, unsigned long len, unsigned long expect)
 325{
 326        z_stream stream;
 327        unsigned char fakebuf[4096];
 328        int st;
 329
 330        memset(&stream, 0, sizeof(stream));
 331        stream.next_in = data;
 332        stream.avail_in = len;
 333        stream.next_out = fakebuf;
 334        stream.avail_out = sizeof(fakebuf);
 335        inflateInit(&stream);
 336
 337        while (1) {
 338                st = inflate(&stream, Z_FINISH);
 339                if (st == Z_STREAM_END || st == Z_OK) {
 340                        st = (stream.total_out == expect &&
 341                              stream.total_in == len) ? 0 : -1;
 342                        break;
 343                }
 344                if (st != Z_BUF_ERROR) {
 345                        st = -1;
 346                        break;
 347                }
 348                stream.next_out = fakebuf;
 349                stream.avail_out = sizeof(fakebuf);
 350        }
 351        inflateEnd(&stream);
 352        return st;
 353}
 354
 355static int revalidate_loose_object(struct object_entry *entry,
 356                                   unsigned char *map,
 357                                   unsigned long mapsize)
 358{
 359        /* we already know this is a loose object with new type header. */
 360        enum object_type type;
 361        unsigned long size, used;
 362
 363        if (pack_to_stdout)
 364                return 0;
 365
 366        used = unpack_object_header_gently(map, mapsize, &type, &size);
 367        if (!used)
 368                return -1;
 369        map += used;
 370        mapsize -= used;
 371        return check_loose_inflate(map, mapsize, size);
 372}
 373
 374static unsigned long write_object(struct sha1file *f,
 375                                  struct object_entry *entry)
 376{
 377        unsigned long size;
 378        char type[10];
 379        void *buf;
 380        unsigned char header[10];
 381        unsigned hdrlen, datalen;
 382        enum object_type obj_type;
 383        int to_reuse = 0;
 384
 385        obj_type = entry->type;
 386        if (! entry->in_pack)
 387                to_reuse = 0;   /* can't reuse what we don't have */
 388        else if (obj_type == OBJ_REF_DELTA || obj_type == OBJ_OFS_DELTA)
 389                to_reuse = 1;   /* check_object() decided it for us */
 390        else if (obj_type != entry->in_pack_type)
 391                to_reuse = 0;   /* pack has delta which is unusable */
 392        else if (entry->delta)
 393                to_reuse = 0;   /* we want to pack afresh */
 394        else
 395                to_reuse = 1;   /* we have it in-pack undeltified,
 396                                 * and we do not need to deltify it.
 397                                 */
 398
 399        if (!entry->in_pack && !entry->delta) {
 400                unsigned char *map;
 401                unsigned long mapsize;
 402                map = map_sha1_file(entry->sha1, &mapsize);
 403                if (map && !legacy_loose_object(map)) {
 404                        /* We can copy straight into the pack file */
 405                        if (revalidate_loose_object(entry, map, mapsize))
 406                                die("corrupt loose object %s",
 407                                    sha1_to_hex(entry->sha1));
 408                        sha1write(f, map, mapsize);
 409                        munmap(map, mapsize);
 410                        written++;
 411                        reused++;
 412                        return mapsize;
 413                }
 414                if (map)
 415                        munmap(map, mapsize);
 416        }
 417
 418        if (!to_reuse) {
 419                buf = read_sha1_file(entry->sha1, type, &size);
 420                if (!buf)
 421                        die("unable to read %s", sha1_to_hex(entry->sha1));
 422                if (size != entry->size)
 423                        die("object %s size inconsistency (%lu vs %lu)",
 424                            sha1_to_hex(entry->sha1), size, entry->size);
 425                if (entry->delta) {
 426                        buf = delta_against(buf, size, entry);
 427                        size = entry->delta_size;
 428                        obj_type = (allow_ofs_delta && entry->delta->offset) ?
 429                                OBJ_OFS_DELTA : OBJ_REF_DELTA;
 430                }
 431                /*
 432                 * The object header is a byte of 'type' followed by zero or
 433                 * more bytes of length.
 434                 */
 435                hdrlen = encode_header(obj_type, size, header);
 436                sha1write(f, header, hdrlen);
 437
 438                if (obj_type == OBJ_OFS_DELTA) {
 439                        /*
 440                         * Deltas with relative base contain an additional
 441                         * encoding of the relative offset for the delta
 442                         * base from this object's position in the pack.
 443                         */
 444                        unsigned long ofs = entry->offset - entry->delta->offset;
 445                        unsigned pos = sizeof(header) - 1;
 446                        header[pos] = ofs & 127;
 447                        while (ofs >>= 7)
 448                                header[--pos] = 128 | (--ofs & 127);
 449                        sha1write(f, header + pos, sizeof(header) - pos);
 450                        hdrlen += sizeof(header) - pos;
 451                } else if (obj_type == OBJ_REF_DELTA) {
 452                        /*
 453                         * Deltas with a base reference contain
 454                         * an additional 20 bytes for the base sha1.
 455                         */
 456                        sha1write(f, entry->delta->sha1, 20);
 457                        hdrlen += 20;
 458                }
 459                datalen = sha1write_compressed(f, buf, size);
 460                free(buf);
 461        }
 462        else {
 463                struct packed_git *p = entry->in_pack;
 464                struct pack_window *w_curs = NULL;
 465                unsigned long offset;
 466
 467                if (entry->delta) {
 468                        obj_type = (allow_ofs_delta && entry->delta->offset) ?
 469                                OBJ_OFS_DELTA : OBJ_REF_DELTA;
 470                        reused_delta++;
 471                }
 472                hdrlen = encode_header(obj_type, entry->size, header);
 473                sha1write(f, header, hdrlen);
 474                if (obj_type == OBJ_OFS_DELTA) {
 475                        unsigned long ofs = entry->offset - entry->delta->offset;
 476                        unsigned pos = sizeof(header) - 1;
 477                        header[pos] = ofs & 127;
 478                        while (ofs >>= 7)
 479                                header[--pos] = 128 | (--ofs & 127);
 480                        sha1write(f, header + pos, sizeof(header) - pos);
 481                        hdrlen += sizeof(header) - pos;
 482                } else if (obj_type == OBJ_REF_DELTA) {
 483                        sha1write(f, entry->delta->sha1, 20);
 484                        hdrlen += 20;
 485                }
 486
 487                offset = entry->in_pack_offset + entry->in_pack_header_size;
 488                datalen = find_packed_object_size(p, entry->in_pack_offset)
 489                                - entry->in_pack_header_size;
 490                if (!pack_to_stdout && check_pack_inflate(p, &w_curs,
 491                                offset, datalen, entry->size))
 492                        die("corrupt delta in pack %s", sha1_to_hex(entry->sha1));
 493                copy_pack_data(f, p, &w_curs, offset, datalen);
 494                unuse_pack(&w_curs);
 495                reused++;
 496        }
 497        if (entry->delta)
 498                written_delta++;
 499        written++;
 500        return hdrlen + datalen;
 501}
 502
 503static unsigned long write_one(struct sha1file *f,
 504                               struct object_entry *e,
 505                               unsigned long offset)
 506{
 507        if (e->offset || e->preferred_base)
 508                /* offset starts from header size and cannot be zero
 509                 * if it is written already.
 510                 */
 511                return offset;
 512        /* if we are deltified, write out its base object first. */
 513        if (e->delta)
 514                offset = write_one(f, e->delta, offset);
 515        e->offset = offset;
 516        return offset + write_object(f, e);
 517}
 518
 519static void write_pack_file(void)
 520{
 521        int i;
 522        struct sha1file *f;
 523        unsigned long offset;
 524        struct pack_header hdr;
 525        unsigned last_percent = 999;
 526        int do_progress = progress;
 527
 528        if (!base_name) {
 529                f = sha1fd(1, "<stdout>");
 530                do_progress >>= 1;
 531        }
 532        else
 533                f = sha1create("%s-%s.%s", base_name,
 534                               sha1_to_hex(object_list_sha1), "pack");
 535        if (do_progress)
 536                fprintf(stderr, "Writing %d objects.\n", nr_result);
 537
 538        hdr.hdr_signature = htonl(PACK_SIGNATURE);
 539        hdr.hdr_version = htonl(PACK_VERSION);
 540        hdr.hdr_entries = htonl(nr_result);
 541        sha1write(f, &hdr, sizeof(hdr));
 542        offset = sizeof(hdr);
 543        if (!nr_result)
 544                goto done;
 545        for (i = 0; i < nr_objects; i++) {
 546                offset = write_one(f, objects + i, offset);
 547                if (do_progress) {
 548                        unsigned percent = written * 100 / nr_result;
 549                        if (progress_update || percent != last_percent) {
 550                                fprintf(stderr, "%4u%% (%u/%u) done\r",
 551                                        percent, written, nr_result);
 552                                progress_update = 0;
 553                                last_percent = percent;
 554                        }
 555                }
 556        }
 557        if (do_progress)
 558                fputc('\n', stderr);
 559 done:
 560        if (written != nr_result)
 561                die("wrote %d objects while expecting %d", written, nr_result);
 562        sha1close(f, pack_file_sha1, 1);
 563}
 564
 565static void write_index_file(void)
 566{
 567        int i;
 568        struct sha1file *f = sha1create("%s-%s.%s", base_name,
 569                                        sha1_to_hex(object_list_sha1), "idx");
 570        struct object_entry **list = sorted_by_sha;
 571        struct object_entry **last = list + nr_result;
 572        uint32_t array[256];
 573
 574        /*
 575         * Write the first-level table (the list is sorted,
 576         * but we use a 256-entry lookup to be able to avoid
 577         * having to do eight extra binary search iterations).
 578         */
 579        for (i = 0; i < 256; i++) {
 580                struct object_entry **next = list;
 581                while (next < last) {
 582                        struct object_entry *entry = *next;
 583                        if (entry->sha1[0] != i)
 584                                break;
 585                        next++;
 586                }
 587                array[i] = htonl(next - sorted_by_sha);
 588                list = next;
 589        }
 590        sha1write(f, array, 256 * 4);
 591
 592        /*
 593         * Write the actual SHA1 entries..
 594         */
 595        list = sorted_by_sha;
 596        for (i = 0; i < nr_result; i++) {
 597                struct object_entry *entry = *list++;
 598                uint32_t offset = htonl(entry->offset);
 599                sha1write(f, &offset, 4);
 600                sha1write(f, entry->sha1, 20);
 601        }
 602        sha1write(f, pack_file_sha1, 20);
 603        sha1close(f, NULL, 1);
 604}
 605
 606static int locate_object_entry_hash(const unsigned char *sha1)
 607{
 608        int i;
 609        unsigned int ui;
 610        memcpy(&ui, sha1, sizeof(unsigned int));
 611        i = ui % object_ix_hashsz;
 612        while (0 < object_ix[i]) {
 613                if (!hashcmp(sha1, objects[object_ix[i] - 1].sha1))
 614                        return i;
 615                if (++i == object_ix_hashsz)
 616                        i = 0;
 617        }
 618        return -1 - i;
 619}
 620
 621static struct object_entry *locate_object_entry(const unsigned char *sha1)
 622{
 623        int i;
 624
 625        if (!object_ix_hashsz)
 626                return NULL;
 627
 628        i = locate_object_entry_hash(sha1);
 629        if (0 <= i)
 630                return &objects[object_ix[i]-1];
 631        return NULL;
 632}
 633
 634static void rehash_objects(void)
 635{
 636        int i;
 637        struct object_entry *oe;
 638
 639        object_ix_hashsz = nr_objects * 3;
 640        if (object_ix_hashsz < 1024)
 641                object_ix_hashsz = 1024;
 642        object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
 643        memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
 644        for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
 645                int ix = locate_object_entry_hash(oe->sha1);
 646                if (0 <= ix)
 647                        continue;
 648                ix = -1 - ix;
 649                object_ix[ix] = i + 1;
 650        }
 651}
 652
 653static unsigned name_hash(const char *name)
 654{
 655        unsigned char c;
 656        unsigned hash = 0;
 657
 658        /*
 659         * This effectively just creates a sortable number from the
 660         * last sixteen non-whitespace characters. Last characters
 661         * count "most", so things that end in ".c" sort together.
 662         */
 663        while ((c = *name++) != 0) {
 664                if (isspace(c))
 665                        continue;
 666                hash = (hash >> 2) + (c << 24);
 667        }
 668        return hash;
 669}
 670
 671static int add_object_entry(const unsigned char *sha1, unsigned hash, int exclude)
 672{
 673        unsigned int idx = nr_objects;
 674        struct object_entry *entry;
 675        struct packed_git *p;
 676        unsigned int found_offset = 0;
 677        struct packed_git *found_pack = NULL;
 678        int ix, status = 0;
 679
 680        if (!exclude) {
 681                for (p = packed_git; p; p = p->next) {
 682                        unsigned long offset = find_pack_entry_one(sha1, p);
 683                        if (offset) {
 684                                if (incremental)
 685                                        return 0;
 686                                if (local && !p->pack_local)
 687                                        return 0;
 688                                if (!found_pack) {
 689                                        found_offset = offset;
 690                                        found_pack = p;
 691                                }
 692                        }
 693                }
 694        }
 695        if ((entry = locate_object_entry(sha1)) != NULL)
 696                goto already_added;
 697
 698        if (idx >= nr_alloc) {
 699                unsigned int needed = (idx + 1024) * 3 / 2;
 700                objects = xrealloc(objects, needed * sizeof(*entry));
 701                nr_alloc = needed;
 702        }
 703        entry = objects + idx;
 704        nr_objects = idx + 1;
 705        memset(entry, 0, sizeof(*entry));
 706        hashcpy(entry->sha1, sha1);
 707        entry->hash = hash;
 708
 709        if (object_ix_hashsz * 3 <= nr_objects * 4)
 710                rehash_objects();
 711        else {
 712                ix = locate_object_entry_hash(entry->sha1);
 713                if (0 <= ix)
 714                        die("internal error in object hashing.");
 715                object_ix[-1 - ix] = idx + 1;
 716        }
 717        status = 1;
 718
 719 already_added:
 720        if (progress_update) {
 721                fprintf(stderr, "Counting objects...%d\r", nr_objects);
 722                progress_update = 0;
 723        }
 724        if (exclude)
 725                entry->preferred_base = 1;
 726        else {
 727                if (found_pack) {
 728                        entry->in_pack = found_pack;
 729                        entry->in_pack_offset = found_offset;
 730                }
 731        }
 732        return status;
 733}
 734
 735struct pbase_tree_cache {
 736        unsigned char sha1[20];
 737        int ref;
 738        int temporary;
 739        void *tree_data;
 740        unsigned long tree_size;
 741};
 742
 743static struct pbase_tree_cache *(pbase_tree_cache[256]);
 744static int pbase_tree_cache_ix(const unsigned char *sha1)
 745{
 746        return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
 747}
 748static int pbase_tree_cache_ix_incr(int ix)
 749{
 750        return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
 751}
 752
 753static struct pbase_tree {
 754        struct pbase_tree *next;
 755        /* This is a phony "cache" entry; we are not
 756         * going to evict it nor find it through _get()
 757         * mechanism -- this is for the toplevel node that
 758         * would almost always change with any commit.
 759         */
 760        struct pbase_tree_cache pcache;
 761} *pbase_tree;
 762
 763static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
 764{
 765        struct pbase_tree_cache *ent, *nent;
 766        void *data;
 767        unsigned long size;
 768        char type[20];
 769        int neigh;
 770        int my_ix = pbase_tree_cache_ix(sha1);
 771        int available_ix = -1;
 772
 773        /* pbase-tree-cache acts as a limited hashtable.
 774         * your object will be found at your index or within a few
 775         * slots after that slot if it is cached.
 776         */
 777        for (neigh = 0; neigh < 8; neigh++) {
 778                ent = pbase_tree_cache[my_ix];
 779                if (ent && !hashcmp(ent->sha1, sha1)) {
 780                        ent->ref++;
 781                        return ent;
 782                }
 783                else if (((available_ix < 0) && (!ent || !ent->ref)) ||
 784                         ((0 <= available_ix) &&
 785                          (!ent && pbase_tree_cache[available_ix])))
 786                        available_ix = my_ix;
 787                if (!ent)
 788                        break;
 789                my_ix = pbase_tree_cache_ix_incr(my_ix);
 790        }
 791
 792        /* Did not find one.  Either we got a bogus request or
 793         * we need to read and perhaps cache.
 794         */
 795        data = read_sha1_file(sha1, type, &size);
 796        if (!data)
 797                return NULL;
 798        if (strcmp(type, tree_type)) {
 799                free(data);
 800                return NULL;
 801        }
 802
 803        /* We need to either cache or return a throwaway copy */
 804
 805        if (available_ix < 0)
 806                ent = NULL;
 807        else {
 808                ent = pbase_tree_cache[available_ix];
 809                my_ix = available_ix;
 810        }
 811
 812        if (!ent) {
 813                nent = xmalloc(sizeof(*nent));
 814                nent->temporary = (available_ix < 0);
 815        }
 816        else {
 817                /* evict and reuse */
 818                free(ent->tree_data);
 819                nent = ent;
 820        }
 821        hashcpy(nent->sha1, sha1);
 822        nent->tree_data = data;
 823        nent->tree_size = size;
 824        nent->ref = 1;
 825        if (!nent->temporary)
 826                pbase_tree_cache[my_ix] = nent;
 827        return nent;
 828}
 829
 830static void pbase_tree_put(struct pbase_tree_cache *cache)
 831{
 832        if (!cache->temporary) {
 833                cache->ref--;
 834                return;
 835        }
 836        free(cache->tree_data);
 837        free(cache);
 838}
 839
 840static int name_cmp_len(const char *name)
 841{
 842        int i;
 843        for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
 844                ;
 845        return i;
 846}
 847
 848static void add_pbase_object(struct tree_desc *tree,
 849                             const char *name,
 850                             int cmplen,
 851                             const char *fullname)
 852{
 853        struct name_entry entry;
 854
 855        while (tree_entry(tree,&entry)) {
 856                unsigned long size;
 857                char type[20];
 858
 859                if (entry.pathlen != cmplen ||
 860                    memcmp(entry.path, name, cmplen) ||
 861                    !has_sha1_file(entry.sha1) ||
 862                    sha1_object_info(entry.sha1, type, &size))
 863                        continue;
 864                if (name[cmplen] != '/') {
 865                        unsigned hash = name_hash(fullname);
 866                        add_object_entry(entry.sha1, hash, 1);
 867                        return;
 868                }
 869                if (!strcmp(type, tree_type)) {
 870                        struct tree_desc sub;
 871                        struct pbase_tree_cache *tree;
 872                        const char *down = name+cmplen+1;
 873                        int downlen = name_cmp_len(down);
 874
 875                        tree = pbase_tree_get(entry.sha1);
 876                        if (!tree)
 877                                return;
 878                        sub.buf = tree->tree_data;
 879                        sub.size = tree->tree_size;
 880
 881                        add_pbase_object(&sub, down, downlen, fullname);
 882                        pbase_tree_put(tree);
 883                }
 884        }
 885}
 886
 887static unsigned *done_pbase_paths;
 888static int done_pbase_paths_num;
 889static int done_pbase_paths_alloc;
 890static int done_pbase_path_pos(unsigned hash)
 891{
 892        int lo = 0;
 893        int hi = done_pbase_paths_num;
 894        while (lo < hi) {
 895                int mi = (hi + lo) / 2;
 896                if (done_pbase_paths[mi] == hash)
 897                        return mi;
 898                if (done_pbase_paths[mi] < hash)
 899                        hi = mi;
 900                else
 901                        lo = mi + 1;
 902        }
 903        return -lo-1;
 904}
 905
 906static int check_pbase_path(unsigned hash)
 907{
 908        int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
 909        if (0 <= pos)
 910                return 1;
 911        pos = -pos - 1;
 912        if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 913                done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 914                done_pbase_paths = xrealloc(done_pbase_paths,
 915                                            done_pbase_paths_alloc *
 916                                            sizeof(unsigned));
 917        }
 918        done_pbase_paths_num++;
 919        if (pos < done_pbase_paths_num)
 920                memmove(done_pbase_paths + pos + 1,
 921                        done_pbase_paths + pos,
 922                        (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
 923        done_pbase_paths[pos] = hash;
 924        return 0;
 925}
 926
 927static void add_preferred_base_object(const char *name, unsigned hash)
 928{
 929        struct pbase_tree *it;
 930        int cmplen = name_cmp_len(name);
 931
 932        if (check_pbase_path(hash))
 933                return;
 934
 935        for (it = pbase_tree; it; it = it->next) {
 936                if (cmplen == 0) {
 937                        hash = name_hash("");
 938                        add_object_entry(it->pcache.sha1, hash, 1);
 939                }
 940                else {
 941                        struct tree_desc tree;
 942                        tree.buf = it->pcache.tree_data;
 943                        tree.size = it->pcache.tree_size;
 944                        add_pbase_object(&tree, name, cmplen, name);
 945                }
 946        }
 947}
 948
 949static void add_preferred_base(unsigned char *sha1)
 950{
 951        struct pbase_tree *it;
 952        void *data;
 953        unsigned long size;
 954        unsigned char tree_sha1[20];
 955
 956        if (window <= num_preferred_base++)
 957                return;
 958
 959        data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
 960        if (!data)
 961                return;
 962
 963        for (it = pbase_tree; it; it = it->next) {
 964                if (!hashcmp(it->pcache.sha1, tree_sha1)) {
 965                        free(data);
 966                        return;
 967                }
 968        }
 969
 970        it = xcalloc(1, sizeof(*it));
 971        it->next = pbase_tree;
 972        pbase_tree = it;
 973
 974        hashcpy(it->pcache.sha1, tree_sha1);
 975        it->pcache.tree_data = data;
 976        it->pcache.tree_size = size;
 977}
 978
 979static void check_object(struct object_entry *entry)
 980{
 981        char type[20];
 982
 983        if (entry->in_pack && !entry->preferred_base) {
 984                struct packed_git *p = entry->in_pack;
 985                struct pack_window *w_curs = NULL;
 986                unsigned long left = p->pack_size - entry->in_pack_offset;
 987                unsigned long size, used;
 988                unsigned char *buf;
 989                struct object_entry *base_entry = NULL;
 990
 991                buf = use_pack(p, &w_curs, entry->in_pack_offset, NULL);
 992
 993                /* We want in_pack_type even if we do not reuse delta.
 994                 * There is no point not reusing non-delta representations.
 995                 */
 996                used = unpack_object_header_gently(buf, left,
 997                                                   &entry->in_pack_type, &size);
 998
 999                /* Check if it is delta, and the base is also an object
1000                 * we are going to pack.  If so we will reuse the existing
1001                 * delta.
1002                 */
1003                if (!no_reuse_delta) {
1004                        unsigned char c, *base_name;
1005                        unsigned long ofs;
1006                        unsigned long used_0;
1007                        /* there is at least 20 bytes left in the pack */
1008                        switch (entry->in_pack_type) {
1009                        case OBJ_REF_DELTA:
1010                                base_name = use_pack(p, &w_curs,
1011                                        entry->in_pack_offset + used, NULL);
1012                                used += 20;
1013                                break;
1014                        case OBJ_OFS_DELTA:
1015                                buf = use_pack(p, &w_curs,
1016                                        entry->in_pack_offset + used, NULL);
1017                                used_0 = 0;
1018                                c = buf[used_0++];
1019                                ofs = c & 127;
1020                                while (c & 128) {
1021                                        ofs += 1;
1022                                        if (!ofs || ofs & ~(~0UL >> 7))
1023                                                die("delta base offset overflow in pack for %s",
1024                                                    sha1_to_hex(entry->sha1));
1025                                        c = buf[used_0++];
1026                                        ofs = (ofs << 7) + (c & 127);
1027                                }
1028                                if (ofs >= entry->in_pack_offset)
1029                                        die("delta base offset out of bound for %s",
1030                                            sha1_to_hex(entry->sha1));
1031                                ofs = entry->in_pack_offset - ofs;
1032                                base_name = find_packed_object_name(p, ofs);
1033                                used += used_0;
1034                                break;
1035                        default:
1036                                base_name = NULL;
1037                        }
1038                        if (base_name)
1039                                base_entry = locate_object_entry(base_name);
1040                }
1041                unuse_pack(&w_curs);
1042                entry->in_pack_header_size = used;
1043
1044                if (base_entry) {
1045
1046                        /* Depth value does not matter - find_deltas()
1047                         * will never consider reused delta as the
1048                         * base object to deltify other objects
1049                         * against, in order to avoid circular deltas.
1050                         */
1051
1052                        /* uncompressed size of the delta data */
1053                        entry->size = size;
1054                        entry->delta = base_entry;
1055                        entry->type = entry->in_pack_type;
1056
1057                        entry->delta_sibling = base_entry->delta_child;
1058                        base_entry->delta_child = entry;
1059
1060                        return;
1061                }
1062                /* Otherwise we would do the usual */
1063        }
1064
1065        if (sha1_object_info(entry->sha1, type, &entry->size))
1066                die("unable to get type of object %s",
1067                    sha1_to_hex(entry->sha1));
1068
1069        if (!strcmp(type, commit_type)) {
1070                entry->type = OBJ_COMMIT;
1071        } else if (!strcmp(type, tree_type)) {
1072                entry->type = OBJ_TREE;
1073        } else if (!strcmp(type, blob_type)) {
1074                entry->type = OBJ_BLOB;
1075        } else if (!strcmp(type, tag_type)) {
1076                entry->type = OBJ_TAG;
1077        } else
1078                die("unable to pack object %s of type %s",
1079                    sha1_to_hex(entry->sha1), type);
1080}
1081
1082static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1083{
1084        struct object_entry *child = me->delta_child;
1085        unsigned int m = n;
1086        while (child) {
1087                unsigned int c = check_delta_limit(child, n + 1);
1088                if (m < c)
1089                        m = c;
1090                child = child->delta_sibling;
1091        }
1092        return m;
1093}
1094
1095static void get_object_details(void)
1096{
1097        int i;
1098        struct object_entry *entry;
1099
1100        prepare_pack_ix();
1101        for (i = 0, entry = objects; i < nr_objects; i++, entry++)
1102                check_object(entry);
1103
1104        if (nr_objects == nr_result) {
1105                /*
1106                 * Depth of objects that depend on the entry -- this
1107                 * is subtracted from depth-max to break too deep
1108                 * delta chain because of delta data reusing.
1109                 * However, we loosen this restriction when we know we
1110                 * are creating a thin pack -- it will have to be
1111                 * expanded on the other end anyway, so do not
1112                 * artificially cut the delta chain and let it go as
1113                 * deep as it wants.
1114                 */
1115                for (i = 0, entry = objects; i < nr_objects; i++, entry++)
1116                        if (!entry->delta && entry->delta_child)
1117                                entry->delta_limit =
1118                                        check_delta_limit(entry, 1);
1119        }
1120}
1121
1122typedef int (*entry_sort_t)(const struct object_entry *, const struct object_entry *);
1123
1124static entry_sort_t current_sort;
1125
1126static int sort_comparator(const void *_a, const void *_b)
1127{
1128        struct object_entry *a = *(struct object_entry **)_a;
1129        struct object_entry *b = *(struct object_entry **)_b;
1130        return current_sort(a,b);
1131}
1132
1133static struct object_entry **create_sorted_list(entry_sort_t sort)
1134{
1135        struct object_entry **list = xmalloc(nr_objects * sizeof(struct object_entry *));
1136        int i;
1137
1138        for (i = 0; i < nr_objects; i++)
1139                list[i] = objects + i;
1140        current_sort = sort;
1141        qsort(list, nr_objects, sizeof(struct object_entry *), sort_comparator);
1142        return list;
1143}
1144
1145static int sha1_sort(const struct object_entry *a, const struct object_entry *b)
1146{
1147        return hashcmp(a->sha1, b->sha1);
1148}
1149
1150static struct object_entry **create_final_object_list(void)
1151{
1152        struct object_entry **list;
1153        int i, j;
1154
1155        for (i = nr_result = 0; i < nr_objects; i++)
1156                if (!objects[i].preferred_base)
1157                        nr_result++;
1158        list = xmalloc(nr_result * sizeof(struct object_entry *));
1159        for (i = j = 0; i < nr_objects; i++) {
1160                if (!objects[i].preferred_base)
1161                        list[j++] = objects + i;
1162        }
1163        current_sort = sha1_sort;
1164        qsort(list, nr_result, sizeof(struct object_entry *), sort_comparator);
1165        return list;
1166}
1167
1168static int type_size_sort(const struct object_entry *a, const struct object_entry *b)
1169{
1170        if (a->type < b->type)
1171                return -1;
1172        if (a->type > b->type)
1173                return 1;
1174        if (a->hash < b->hash)
1175                return -1;
1176        if (a->hash > b->hash)
1177                return 1;
1178        if (a->preferred_base < b->preferred_base)
1179                return -1;
1180        if (a->preferred_base > b->preferred_base)
1181                return 1;
1182        if (a->size < b->size)
1183                return -1;
1184        if (a->size > b->size)
1185                return 1;
1186        return a < b ? -1 : (a > b);
1187}
1188
1189struct unpacked {
1190        struct object_entry *entry;
1191        void *data;
1192        struct delta_index *index;
1193};
1194
1195/*
1196 * We search for deltas _backwards_ in a list sorted by type and
1197 * by size, so that we see progressively smaller and smaller files.
1198 * That's because we prefer deltas to be from the bigger file
1199 * to the smaller - deletes are potentially cheaper, but perhaps
1200 * more importantly, the bigger file is likely the more recent
1201 * one.
1202 */
1203static int try_delta(struct unpacked *trg, struct unpacked *src,
1204                     unsigned max_depth)
1205{
1206        struct object_entry *trg_entry = trg->entry;
1207        struct object_entry *src_entry = src->entry;
1208        unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1209        char type[10];
1210        void *delta_buf;
1211
1212        /* Don't bother doing diffs between different types */
1213        if (trg_entry->type != src_entry->type)
1214                return -1;
1215
1216        /* We do not compute delta to *create* objects we are not
1217         * going to pack.
1218         */
1219        if (trg_entry->preferred_base)
1220                return -1;
1221
1222        /*
1223         * We do not bother to try a delta that we discarded
1224         * on an earlier try, but only when reusing delta data.
1225         */
1226        if (!no_reuse_delta && trg_entry->in_pack &&
1227            trg_entry->in_pack == src_entry->in_pack &&
1228            trg_entry->in_pack_type != OBJ_REF_DELTA &&
1229            trg_entry->in_pack_type != OBJ_OFS_DELTA)
1230                return 0;
1231
1232        /*
1233         * If the current object is at pack edge, take the depth the
1234         * objects that depend on the current object into account --
1235         * otherwise they would become too deep.
1236         */
1237        if (trg_entry->delta_child) {
1238                if (max_depth <= trg_entry->delta_limit)
1239                        return 0;
1240                max_depth -= trg_entry->delta_limit;
1241        }
1242        if (src_entry->depth >= max_depth)
1243                return 0;
1244
1245        /* Now some size filtering heuristics. */
1246        trg_size = trg_entry->size;
1247        max_size = trg_size/2 - 20;
1248        max_size = max_size * (max_depth - src_entry->depth) / max_depth;
1249        if (max_size == 0)
1250                return 0;
1251        if (trg_entry->delta && trg_entry->delta_size <= max_size)
1252                max_size = trg_entry->delta_size-1;
1253        src_size = src_entry->size;
1254        sizediff = src_size < trg_size ? trg_size - src_size : 0;
1255        if (sizediff >= max_size)
1256                return 0;
1257
1258        /* Load data if not already done */
1259        if (!trg->data) {
1260                trg->data = read_sha1_file(trg_entry->sha1, type, &sz);
1261                if (sz != trg_size)
1262                        die("object %s inconsistent object length (%lu vs %lu)",
1263                            sha1_to_hex(trg_entry->sha1), sz, trg_size);
1264        }
1265        if (!src->data) {
1266                src->data = read_sha1_file(src_entry->sha1, type, &sz);
1267                if (sz != src_size)
1268                        die("object %s inconsistent object length (%lu vs %lu)",
1269                            sha1_to_hex(src_entry->sha1), sz, src_size);
1270        }
1271        if (!src->index) {
1272                src->index = create_delta_index(src->data, src_size);
1273                if (!src->index)
1274                        die("out of memory");
1275        }
1276
1277        delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1278        if (!delta_buf)
1279                return 0;
1280
1281        trg_entry->delta = src_entry;
1282        trg_entry->delta_size = delta_size;
1283        trg_entry->depth = src_entry->depth + 1;
1284        free(delta_buf);
1285        return 1;
1286}
1287
1288static void progress_interval(int signum)
1289{
1290        progress_update = 1;
1291}
1292
1293static void find_deltas(struct object_entry **list, int window, int depth)
1294{
1295        int i, idx;
1296        unsigned int array_size = window * sizeof(struct unpacked);
1297        struct unpacked *array = xmalloc(array_size);
1298        unsigned processed = 0;
1299        unsigned last_percent = 999;
1300
1301        memset(array, 0, array_size);
1302        i = nr_objects;
1303        idx = 0;
1304        if (progress)
1305                fprintf(stderr, "Deltifying %d objects.\n", nr_result);
1306
1307        while (--i >= 0) {
1308                struct object_entry *entry = list[i];
1309                struct unpacked *n = array + idx;
1310                int j;
1311
1312                if (!entry->preferred_base)
1313                        processed++;
1314
1315                if (progress) {
1316                        unsigned percent = processed * 100 / nr_result;
1317                        if (percent != last_percent || progress_update) {
1318                                fprintf(stderr, "%4u%% (%u/%u) done\r",
1319                                        percent, processed, nr_result);
1320                                progress_update = 0;
1321                                last_percent = percent;
1322                        }
1323                }
1324
1325                if (entry->delta)
1326                        /* This happens if we decided to reuse existing
1327                         * delta from a pack.  "!no_reuse_delta &&" is implied.
1328                         */
1329                        continue;
1330
1331                if (entry->size < 50)
1332                        continue;
1333                free_delta_index(n->index);
1334                n->index = NULL;
1335                free(n->data);
1336                n->data = NULL;
1337                n->entry = entry;
1338
1339                j = window;
1340                while (--j > 0) {
1341                        unsigned int other_idx = idx + j;
1342                        struct unpacked *m;
1343                        if (other_idx >= window)
1344                                other_idx -= window;
1345                        m = array + other_idx;
1346                        if (!m->entry)
1347                                break;
1348                        if (try_delta(n, m, depth) < 0)
1349                                break;
1350                }
1351                /* if we made n a delta, and if n is already at max
1352                 * depth, leaving it in the window is pointless.  we
1353                 * should evict it first.
1354                 */
1355                if (entry->delta && depth <= entry->depth)
1356                        continue;
1357
1358                idx++;
1359                if (idx >= window)
1360                        idx = 0;
1361        }
1362
1363        if (progress)
1364                fputc('\n', stderr);
1365
1366        for (i = 0; i < window; ++i) {
1367                free_delta_index(array[i].index);
1368                free(array[i].data);
1369        }
1370        free(array);
1371}
1372
1373static void prepare_pack(int window, int depth)
1374{
1375        get_object_details();
1376        sorted_by_type = create_sorted_list(type_size_sort);
1377        if (window && depth)
1378                find_deltas(sorted_by_type, window+1, depth);
1379}
1380
1381static int reuse_cached_pack(unsigned char *sha1)
1382{
1383        static const char cache[] = "pack-cache/pack-%s.%s";
1384        char *cached_pack, *cached_idx;
1385        int ifd, ofd, ifd_ix = -1;
1386
1387        cached_pack = git_path(cache, sha1_to_hex(sha1), "pack");
1388        ifd = open(cached_pack, O_RDONLY);
1389        if (ifd < 0)
1390                return 0;
1391
1392        if (!pack_to_stdout) {
1393                cached_idx = git_path(cache, sha1_to_hex(sha1), "idx");
1394                ifd_ix = open(cached_idx, O_RDONLY);
1395                if (ifd_ix < 0) {
1396                        close(ifd);
1397                        return 0;
1398                }
1399        }
1400
1401        if (progress)
1402                fprintf(stderr, "Reusing %d objects pack %s\n", nr_objects,
1403                        sha1_to_hex(sha1));
1404
1405        if (pack_to_stdout) {
1406                if (copy_fd(ifd, 1))
1407                        exit(1);
1408                close(ifd);
1409        }
1410        else {
1411                char name[PATH_MAX];
1412                snprintf(name, sizeof(name),
1413                         "%s-%s.%s", base_name, sha1_to_hex(sha1), "pack");
1414                ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
1415                if (ofd < 0)
1416                        die("unable to open %s (%s)", name, strerror(errno));
1417                if (copy_fd(ifd, ofd))
1418                        exit(1);
1419                close(ifd);
1420
1421                snprintf(name, sizeof(name),
1422                         "%s-%s.%s", base_name, sha1_to_hex(sha1), "idx");
1423                ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
1424                if (ofd < 0)
1425                        die("unable to open %s (%s)", name, strerror(errno));
1426                if (copy_fd(ifd_ix, ofd))
1427                        exit(1);
1428                close(ifd_ix);
1429                puts(sha1_to_hex(sha1));
1430        }
1431
1432        return 1;
1433}
1434
1435static void setup_progress_signal(void)
1436{
1437        struct sigaction sa;
1438        struct itimerval v;
1439
1440        memset(&sa, 0, sizeof(sa));
1441        sa.sa_handler = progress_interval;
1442        sigemptyset(&sa.sa_mask);
1443        sa.sa_flags = SA_RESTART;
1444        sigaction(SIGALRM, &sa, NULL);
1445
1446        v.it_interval.tv_sec = 1;
1447        v.it_interval.tv_usec = 0;
1448        v.it_value = v.it_interval;
1449        setitimer(ITIMER_REAL, &v, NULL);
1450}
1451
1452static int git_pack_config(const char *k, const char *v)
1453{
1454        if(!strcmp(k, "pack.window")) {
1455                window = git_config_int(k, v);
1456                return 0;
1457        }
1458        return git_default_config(k, v);
1459}
1460
1461static void read_object_list_from_stdin(void)
1462{
1463        char line[40 + 1 + PATH_MAX + 2];
1464        unsigned char sha1[20];
1465        unsigned hash;
1466
1467        for (;;) {
1468                if (!fgets(line, sizeof(line), stdin)) {
1469                        if (feof(stdin))
1470                                break;
1471                        if (!ferror(stdin))
1472                                die("fgets returned NULL, not EOF, not error!");
1473                        if (errno != EINTR)
1474                                die("fgets: %s", strerror(errno));
1475                        clearerr(stdin);
1476                        continue;
1477                }
1478                if (line[0] == '-') {
1479                        if (get_sha1_hex(line+1, sha1))
1480                                die("expected edge sha1, got garbage:\n %s",
1481                                    line);
1482                        add_preferred_base(sha1);
1483                        continue;
1484                }
1485                if (get_sha1_hex(line, sha1))
1486                        die("expected sha1, got garbage:\n %s", line);
1487
1488                hash = name_hash(line+41);
1489                add_preferred_base_object(line+41, hash);
1490                add_object_entry(sha1, hash, 0);
1491        }
1492}
1493
1494static void show_commit(struct commit *commit)
1495{
1496        unsigned hash = name_hash("");
1497        add_preferred_base_object("", hash);
1498        add_object_entry(commit->object.sha1, hash, 0);
1499}
1500
1501static void show_object(struct object_array_entry *p)
1502{
1503        unsigned hash = name_hash(p->name);
1504        add_preferred_base_object(p->name, hash);
1505        add_object_entry(p->item->sha1, hash, 0);
1506}
1507
1508static void show_edge(struct commit *commit)
1509{
1510        add_preferred_base(commit->object.sha1);
1511}
1512
1513static void get_object_list(int ac, const char **av)
1514{
1515        struct rev_info revs;
1516        char line[1000];
1517        int flags = 0;
1518
1519        init_revisions(&revs, NULL);
1520        save_commit_buffer = 0;
1521        track_object_refs = 0;
1522        setup_revisions(ac, av, &revs, NULL);
1523
1524        while (fgets(line, sizeof(line), stdin) != NULL) {
1525                int len = strlen(line);
1526                if (line[len - 1] == '\n')
1527                        line[--len] = 0;
1528                if (!len)
1529                        break;
1530                if (*line == '-') {
1531                        if (!strcmp(line, "--not")) {
1532                                flags ^= UNINTERESTING;
1533                                continue;
1534                        }
1535                        die("not a rev '%s'", line);
1536                }
1537                if (handle_revision_arg(line, &revs, flags, 1))
1538                        die("bad revision '%s'", line);
1539        }
1540
1541        prepare_revision_walk(&revs);
1542        mark_edges_uninteresting(revs.commits, &revs, show_edge);
1543        traverse_commit_list(&revs, show_commit, show_object);
1544}
1545
1546int cmd_pack_objects(int argc, const char **argv, const char *prefix)
1547{
1548        SHA_CTX ctx;
1549        int depth = 10;
1550        struct object_entry **list;
1551        int use_internal_rev_list = 0;
1552        int thin = 0;
1553        int i;
1554        const char **rp_av;
1555        int rp_ac_alloc = 64;
1556        int rp_ac;
1557
1558        rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
1559
1560        rp_av[0] = "pack-objects";
1561        rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
1562        rp_ac = 2;
1563
1564        git_config(git_pack_config);
1565
1566        progress = isatty(2);
1567        for (i = 1; i < argc; i++) {
1568                const char *arg = argv[i];
1569
1570                if (*arg != '-')
1571                        break;
1572
1573                if (!strcmp("--non-empty", arg)) {
1574                        non_empty = 1;
1575                        continue;
1576                }
1577                if (!strcmp("--local", arg)) {
1578                        local = 1;
1579                        continue;
1580                }
1581                if (!strcmp("--incremental", arg)) {
1582                        incremental = 1;
1583                        continue;
1584                }
1585                if (!strncmp("--window=", arg, 9)) {
1586                        char *end;
1587                        window = strtoul(arg+9, &end, 0);
1588                        if (!arg[9] || *end)
1589                                usage(pack_usage);
1590                        continue;
1591                }
1592                if (!strncmp("--depth=", arg, 8)) {
1593                        char *end;
1594                        depth = strtoul(arg+8, &end, 0);
1595                        if (!arg[8] || *end)
1596                                usage(pack_usage);
1597                        continue;
1598                }
1599                if (!strcmp("--progress", arg)) {
1600                        progress = 1;
1601                        continue;
1602                }
1603                if (!strcmp("--all-progress", arg)) {
1604                        progress = 2;
1605                        continue;
1606                }
1607                if (!strcmp("-q", arg)) {
1608                        progress = 0;
1609                        continue;
1610                }
1611                if (!strcmp("--no-reuse-delta", arg)) {
1612                        no_reuse_delta = 1;
1613                        continue;
1614                }
1615                if (!strcmp("--delta-base-offset", arg)) {
1616                        allow_ofs_delta = 1;
1617                        continue;
1618                }
1619                if (!strcmp("--stdout", arg)) {
1620                        pack_to_stdout = 1;
1621                        continue;
1622                }
1623                if (!strcmp("--revs", arg)) {
1624                        use_internal_rev_list = 1;
1625                        continue;
1626                }
1627                if (!strcmp("--unpacked", arg) ||
1628                    !strncmp("--unpacked=", arg, 11) ||
1629                    !strcmp("--reflog", arg) ||
1630                    !strcmp("--all", arg)) {
1631                        use_internal_rev_list = 1;
1632                        if (rp_ac >= rp_ac_alloc - 1) {
1633                                rp_ac_alloc = alloc_nr(rp_ac_alloc);
1634                                rp_av = xrealloc(rp_av,
1635                                                 rp_ac_alloc * sizeof(*rp_av));
1636                        }
1637                        rp_av[rp_ac++] = arg;
1638                        continue;
1639                }
1640                if (!strcmp("--thin", arg)) {
1641                        use_internal_rev_list = 1;
1642                        thin = 1;
1643                        rp_av[1] = "--objects-edge";
1644                        continue;
1645                }
1646                usage(pack_usage);
1647        }
1648
1649        /* Traditionally "pack-objects [options] base extra" failed;
1650         * we would however want to take refs parameter that would
1651         * have been given to upstream rev-list ourselves, which means
1652         * we somehow want to say what the base name is.  So the
1653         * syntax would be:
1654         *
1655         * pack-objects [options] base <refs...>
1656         *
1657         * in other words, we would treat the first non-option as the
1658         * base_name and send everything else to the internal revision
1659         * walker.
1660         */
1661
1662        if (!pack_to_stdout)
1663                base_name = argv[i++];
1664
1665        if (pack_to_stdout != !base_name)
1666                usage(pack_usage);
1667
1668        if (!pack_to_stdout && thin)
1669                die("--thin cannot be used to build an indexable pack.");
1670
1671        prepare_packed_git();
1672
1673        if (progress) {
1674                fprintf(stderr, "Generating pack...\n");
1675                setup_progress_signal();
1676        }
1677
1678        if (!use_internal_rev_list)
1679                read_object_list_from_stdin();
1680        else {
1681                rp_av[rp_ac] = NULL;
1682                get_object_list(rp_ac, rp_av);
1683        }
1684
1685        if (progress)
1686                fprintf(stderr, "Done counting %d objects.\n", nr_objects);
1687        sorted_by_sha = create_final_object_list();
1688        if (non_empty && !nr_result)
1689                return 0;
1690
1691        SHA1_Init(&ctx);
1692        list = sorted_by_sha;
1693        for (i = 0; i < nr_result; i++) {
1694                struct object_entry *entry = *list++;
1695                SHA1_Update(&ctx, entry->sha1, 20);
1696        }
1697        SHA1_Final(object_list_sha1, &ctx);
1698        if (progress && (nr_objects != nr_result))
1699                fprintf(stderr, "Result has %d objects.\n", nr_result);
1700
1701        if (reuse_cached_pack(object_list_sha1))
1702                ;
1703        else {
1704                if (nr_result)
1705                        prepare_pack(window, depth);
1706                if (progress == 1 && pack_to_stdout) {
1707                        /* the other end usually displays progress itself */
1708                        struct itimerval v = {{0,},};
1709                        setitimer(ITIMER_REAL, &v, NULL);
1710                        signal(SIGALRM, SIG_IGN );
1711                        progress_update = 0;
1712                }
1713                write_pack_file();
1714                if (!pack_to_stdout) {
1715                        write_index_file();
1716                        puts(sha1_to_hex(object_list_sha1));
1717                }
1718        }
1719        if (progress)
1720                fprintf(stderr, "Total %d (delta %d), reused %d (delta %d)\n",
1721                        written, written_delta, reused, reused_delta);
1722        return 0;
1723}