Code

5c468aa50aa0a591676e0c83ca2de1790e937c87
[git.git] / builtin-pack-objects.c
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 #include "progress.h"
17 static const char pack_usage[] = "\
18 git-pack-objects [{ -q | --progress | --all-progress }] \n\
19         [--local] [--incremental] [--window=N] [--depth=N] \n\
20         [--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
21         [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
22         [--stdout | base-name] [<ref-list | <object-list]";
24 struct object_entry {
25         unsigned char sha1[20];
26         uint32_t crc32;         /* crc of raw pack data for this object */
27         off_t offset;           /* offset into the final pack file */
28         unsigned long size;     /* uncompressed size */
29         unsigned int hash;      /* name hint hash */
30         unsigned int depth;     /* delta depth */
31         struct packed_git *in_pack;     /* already in pack */
32         off_t in_pack_offset;
33         struct object_entry *delta;     /* delta base object */
34         struct object_entry *delta_child; /* deltified objects who bases me */
35         struct object_entry *delta_sibling; /* other deltified objects who
36                                              * uses the same base as me
37                                              */
38         unsigned long delta_size;       /* delta data size (uncompressed) */
39         enum object_type type;
40         enum object_type in_pack_type;  /* could be delta */
41         unsigned char in_pack_header_size;
42         unsigned char preferred_base; /* we do not pack this, but is available
43                                        * to be used as the base objectto delta
44                                        * objects against.
45                                        */
46 };
48 /*
49  * Objects we are going to pack are collected in objects array (dynamically
50  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
51  * in the order we see -- typically rev-list --objects order that gives us
52  * nice "minimum seek" order.
53  */
54 static struct object_entry *objects;
55 static uint32_t nr_objects, nr_alloc, nr_result;
57 static int non_empty;
58 static int no_reuse_delta, no_reuse_object;
59 static int local;
60 static int incremental;
61 static int allow_ofs_delta;
62 static const char *pack_tmp_name, *idx_tmp_name;
63 static char tmpname[PATH_MAX];
64 static unsigned char pack_file_sha1[20];
65 static int progress = 1;
66 static int window = 10;
67 static int depth = 50;
68 static int pack_to_stdout;
69 static int num_preferred_base;
70 static struct progress progress_state;
71 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
72 static int pack_compression_seen;
74 /*
75  * The object names in objects array are hashed with this hashtable,
76  * to help looking up the entry by object name.
77  * This hashtable is built after all the objects are seen.
78  */
79 static int *object_ix;
80 static int object_ix_hashsz;
82 /*
83  * Pack index for existing packs give us easy access to the offsets into
84  * corresponding pack file where each object's data starts, but the entries
85  * do not store the size of the compressed representation (uncompressed
86  * size is easily available by examining the pack entry header).  It is
87  * also rather expensive to find the sha1 for an object given its offset.
88  *
89  * We build a hashtable of existing packs (pack_revindex), and keep reverse
90  * index here -- pack index file is sorted by object name mapping to offset;
91  * this pack_revindex[].revindex array is a list of offset/index_nr pairs
92  * ordered by offset, so if you know the offset of an object, next offset
93  * is where its packed representation ends and the index_nr can be used to
94  * get the object sha1 from the main index.
95  */
96 struct revindex_entry {
97         off_t offset;
98         unsigned int nr;
99 };
100 struct pack_revindex {
101         struct packed_git *p;
102         struct revindex_entry *revindex;
103 };
104 static struct  pack_revindex *pack_revindex;
105 static int pack_revindex_hashsz;
107 /*
108  * stats
109  */
110 static uint32_t written, written_delta;
111 static uint32_t reused, reused_delta;
113 static int pack_revindex_ix(struct packed_git *p)
115         unsigned long ui = (unsigned long)p;
116         int i;
118         ui = ui ^ (ui >> 16); /* defeat structure alignment */
119         i = (int)(ui % pack_revindex_hashsz);
120         while (pack_revindex[i].p) {
121                 if (pack_revindex[i].p == p)
122                         return i;
123                 if (++i == pack_revindex_hashsz)
124                         i = 0;
125         }
126         return -1 - i;
129 static void prepare_pack_ix(void)
131         int num;
132         struct packed_git *p;
133         for (num = 0, p = packed_git; p; p = p->next)
134                 num++;
135         if (!num)
136                 return;
137         pack_revindex_hashsz = num * 11;
138         pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
139         for (p = packed_git; p; p = p->next) {
140                 num = pack_revindex_ix(p);
141                 num = - 1 - num;
142                 pack_revindex[num].p = p;
143         }
144         /* revindex elements are lazily initialized */
147 static int cmp_offset(const void *a_, const void *b_)
149         const struct revindex_entry *a = a_;
150         const struct revindex_entry *b = b_;
151         return (a->offset < b->offset) ? -1 : (a->offset > b->offset) ? 1 : 0;
154 /*
155  * Ordered list of offsets of objects in the pack.
156  */
157 static void prepare_pack_revindex(struct pack_revindex *rix)
159         struct packed_git *p = rix->p;
160         int num_ent = p->num_objects;
161         int i;
162         const char *index = p->index_data;
164         rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1));
165         index += 4 * 256;
167         if (p->index_version > 1) {
168                 const uint32_t *off_32 =
169                         (uint32_t *)(index + 8 + p->num_objects * (20 + 4));
170                 const uint32_t *off_64 = off_32 + p->num_objects;
171                 for (i = 0; i < num_ent; i++) {
172                         uint32_t off = ntohl(*off_32++);
173                         if (!(off & 0x80000000)) {
174                                 rix->revindex[i].offset = off;
175                         } else {
176                                 rix->revindex[i].offset =
177                                         ((uint64_t)ntohl(*off_64++)) << 32;
178                                 rix->revindex[i].offset |=
179                                         ntohl(*off_64++);
180                         }
181                         rix->revindex[i].nr = i;
182                 }
183         } else {
184                 for (i = 0; i < num_ent; i++) {
185                         uint32_t hl = *((uint32_t *)(index + 24 * i));
186                         rix->revindex[i].offset = ntohl(hl);
187                         rix->revindex[i].nr = i;
188                 }
189         }
191         /* This knows the pack format -- the 20-byte trailer
192          * follows immediately after the last object data.
193          */
194         rix->revindex[num_ent].offset = p->pack_size - 20;
195         rix->revindex[num_ent].nr = -1;
196         qsort(rix->revindex, num_ent, sizeof(*rix->revindex), cmp_offset);
199 static struct revindex_entry * find_packed_object(struct packed_git *p,
200                                                   off_t ofs)
202         int num;
203         int lo, hi;
204         struct pack_revindex *rix;
205         struct revindex_entry *revindex;
206         num = pack_revindex_ix(p);
207         if (num < 0)
208                 die("internal error: pack revindex uninitialized");
209         rix = &pack_revindex[num];
210         if (!rix->revindex)
211                 prepare_pack_revindex(rix);
212         revindex = rix->revindex;
213         lo = 0;
214         hi = p->num_objects + 1;
215         do {
216                 int mi = (lo + hi) / 2;
217                 if (revindex[mi].offset == ofs) {
218                         return revindex + mi;
219                 }
220                 else if (ofs < revindex[mi].offset)
221                         hi = mi;
222                 else
223                         lo = mi + 1;
224         } while (lo < hi);
225         die("internal error: pack revindex corrupt");
228 static const unsigned char *find_packed_object_name(struct packed_git *p,
229                                                     off_t ofs)
231         struct revindex_entry *entry = find_packed_object(p, ofs);
232         return nth_packed_object_sha1(p, entry->nr);
235 static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
237         unsigned long othersize, delta_size;
238         enum object_type type;
239         void *otherbuf = read_sha1_file(entry->delta->sha1, &type, &othersize);
240         void *delta_buf;
242         if (!otherbuf)
243                 die("unable to read %s", sha1_to_hex(entry->delta->sha1));
244         delta_buf = diff_delta(otherbuf, othersize,
245                                buf, size, &delta_size, 0);
246         if (!delta_buf || delta_size != entry->delta_size)
247                 die("delta size changed");
248         free(buf);
249         free(otherbuf);
250         return delta_buf;
253 /*
254  * The per-object header is a pretty dense thing, which is
255  *  - first byte: low four bits are "size", then three bits of "type",
256  *    and the high bit is "size continues".
257  *  - each byte afterwards: low seven bits are size continuation,
258  *    with the high bit being "size continues"
259  */
260 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
262         int n = 1;
263         unsigned char c;
265         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
266                 die("bad type %d", type);
268         c = (type << 4) | (size & 15);
269         size >>= 4;
270         while (size) {
271                 *hdr++ = c | 0x80;
272                 c = size & 0x7f;
273                 size >>= 7;
274                 n++;
275         }
276         *hdr = c;
277         return n;
280 /*
281  * we are going to reuse the existing object data as is.  make
282  * sure it is not corrupt.
283  */
284 static int check_pack_inflate(struct packed_git *p,
285                 struct pack_window **w_curs,
286                 off_t offset,
287                 off_t len,
288                 unsigned long expect)
290         z_stream stream;
291         unsigned char fakebuf[4096], *in;
292         int st;
294         memset(&stream, 0, sizeof(stream));
295         inflateInit(&stream);
296         do {
297                 in = use_pack(p, w_curs, offset, &stream.avail_in);
298                 stream.next_in = in;
299                 stream.next_out = fakebuf;
300                 stream.avail_out = sizeof(fakebuf);
301                 st = inflate(&stream, Z_FINISH);
302                 offset += stream.next_in - in;
303         } while (st == Z_OK || st == Z_BUF_ERROR);
304         inflateEnd(&stream);
305         return (st == Z_STREAM_END &&
306                 stream.total_out == expect &&
307                 stream.total_in == len) ? 0 : -1;
310 static int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
311                           off_t offset, off_t len, unsigned int nr)
313         const uint32_t *index_crc;
314         uint32_t data_crc = crc32(0, Z_NULL, 0);
316         do {
317                 unsigned int avail;
318                 void *data = use_pack(p, w_curs, offset, &avail);
319                 if (avail > len)
320                         avail = len;
321                 data_crc = crc32(data_crc, data, avail);
322                 offset += avail;
323                 len -= avail;
324         } while (len);
326         index_crc = p->index_data;
327         index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
329         return data_crc != ntohl(*index_crc);
332 static void copy_pack_data(struct sha1file *f,
333                 struct packed_git *p,
334                 struct pack_window **w_curs,
335                 off_t offset,
336                 off_t len)
338         unsigned char *in;
339         unsigned int avail;
341         while (len) {
342                 in = use_pack(p, w_curs, offset, &avail);
343                 if (avail > len)
344                         avail = (unsigned int)len;
345                 sha1write(f, in, avail);
346                 offset += avail;
347                 len -= avail;
348         }
351 static int check_loose_inflate(unsigned char *data, unsigned long len, unsigned long expect)
353         z_stream stream;
354         unsigned char fakebuf[4096];
355         int st;
357         memset(&stream, 0, sizeof(stream));
358         stream.next_in = data;
359         stream.avail_in = len;
360         stream.next_out = fakebuf;
361         stream.avail_out = sizeof(fakebuf);
362         inflateInit(&stream);
364         while (1) {
365                 st = inflate(&stream, Z_FINISH);
366                 if (st == Z_STREAM_END || st == Z_OK) {
367                         st = (stream.total_out == expect &&
368                               stream.total_in == len) ? 0 : -1;
369                         break;
370                 }
371                 if (st != Z_BUF_ERROR) {
372                         st = -1;
373                         break;
374                 }
375                 stream.next_out = fakebuf;
376                 stream.avail_out = sizeof(fakebuf);
377         }
378         inflateEnd(&stream);
379         return st;
382 static int revalidate_loose_object(struct object_entry *entry,
383                                    unsigned char *map,
384                                    unsigned long mapsize)
386         /* we already know this is a loose object with new type header. */
387         enum object_type type;
388         unsigned long size, used;
390         if (pack_to_stdout)
391                 return 0;
393         used = unpack_object_header_gently(map, mapsize, &type, &size);
394         if (!used)
395                 return -1;
396         map += used;
397         mapsize -= used;
398         return check_loose_inflate(map, mapsize, size);
401 static unsigned long write_object(struct sha1file *f,
402                                   struct object_entry *entry)
404         unsigned long size;
405         enum object_type type;
406         void *buf;
407         unsigned char header[10];
408         unsigned hdrlen;
409         off_t datalen;
410         enum object_type obj_type;
411         int to_reuse = 0;
413         if (!pack_to_stdout)
414                 crc32_begin(f);
416         obj_type = entry->type;
417         if (no_reuse_object)
418                 to_reuse = 0;   /* explicit */
419         else if (!entry->in_pack)
420                 to_reuse = 0;   /* can't reuse what we don't have */
421         else if (obj_type == OBJ_REF_DELTA || obj_type == OBJ_OFS_DELTA)
422                 to_reuse = 1;   /* check_object() decided it for us */
423         else if (obj_type != entry->in_pack_type)
424                 to_reuse = 0;   /* pack has delta which is unusable */
425         else if (entry->delta)
426                 to_reuse = 0;   /* we want to pack afresh */
427         else
428                 to_reuse = 1;   /* we have it in-pack undeltified,
429                                  * and we do not need to deltify it.
430                                  */
432         /* differing core & pack compression when loose object -> must recompress */
433         if (!entry->in_pack && pack_compression_level != zlib_compression_level)
434                 to_reuse = 0;
435         else if (!no_reuse_object && !entry->in_pack && !entry->delta) {
436                 unsigned char *map;
437                 unsigned long mapsize;
438                 map = map_sha1_file(entry->sha1, &mapsize);
439                 if (map && !legacy_loose_object(map)) {
440                         /* We can copy straight into the pack file */
441                         if (revalidate_loose_object(entry, map, mapsize))
442                                 die("corrupt loose object %s",
443                                     sha1_to_hex(entry->sha1));
444                         sha1write(f, map, mapsize);
445                         munmap(map, mapsize);
446                         written++;
447                         reused++;
448                         return mapsize;
449                 }
450                 if (map)
451                         munmap(map, mapsize);
452         }
454         if (!to_reuse) {
455                 buf = read_sha1_file(entry->sha1, &type, &size);
456                 if (!buf)
457                         die("unable to read %s", sha1_to_hex(entry->sha1));
458                 if (size != entry->size)
459                         die("object %s size inconsistency (%lu vs %lu)",
460                             sha1_to_hex(entry->sha1), size, entry->size);
461                 if (entry->delta) {
462                         buf = delta_against(buf, size, entry);
463                         size = entry->delta_size;
464                         obj_type = (allow_ofs_delta && entry->delta->offset) ?
465                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
466                 }
467                 /*
468                  * The object header is a byte of 'type' followed by zero or
469                  * more bytes of length.
470                  */
471                 hdrlen = encode_header(obj_type, size, header);
472                 sha1write(f, header, hdrlen);
474                 if (obj_type == OBJ_OFS_DELTA) {
475                         /*
476                          * Deltas with relative base contain an additional
477                          * encoding of the relative offset for the delta
478                          * base from this object's position in the pack.
479                          */
480                         off_t ofs = entry->offset - entry->delta->offset;
481                         unsigned pos = sizeof(header) - 1;
482                         header[pos] = ofs & 127;
483                         while (ofs >>= 7)
484                                 header[--pos] = 128 | (--ofs & 127);
485                         sha1write(f, header + pos, sizeof(header) - pos);
486                         hdrlen += sizeof(header) - pos;
487                 } else if (obj_type == OBJ_REF_DELTA) {
488                         /*
489                          * Deltas with a base reference contain
490                          * an additional 20 bytes for the base sha1.
491                          */
492                         sha1write(f, entry->delta->sha1, 20);
493                         hdrlen += 20;
494                 }
495                 datalen = sha1write_compressed(f, buf, size, pack_compression_level);
496                 free(buf);
497         }
498         else {
499                 struct packed_git *p = entry->in_pack;
500                 struct pack_window *w_curs = NULL;
501                 struct revindex_entry *revidx;
502                 off_t offset;
504                 if (entry->delta) {
505                         obj_type = (allow_ofs_delta && entry->delta->offset) ?
506                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
507                         reused_delta++;
508                 }
509                 hdrlen = encode_header(obj_type, entry->size, header);
510                 sha1write(f, header, hdrlen);
511                 if (obj_type == OBJ_OFS_DELTA) {
512                         off_t ofs = entry->offset - entry->delta->offset;
513                         unsigned pos = sizeof(header) - 1;
514                         header[pos] = ofs & 127;
515                         while (ofs >>= 7)
516                                 header[--pos] = 128 | (--ofs & 127);
517                         sha1write(f, header + pos, sizeof(header) - pos);
518                         hdrlen += sizeof(header) - pos;
519                 } else if (obj_type == OBJ_REF_DELTA) {
520                         sha1write(f, entry->delta->sha1, 20);
521                         hdrlen += 20;
522                 }
524                 offset = entry->in_pack_offset;
525                 revidx = find_packed_object(p, offset);
526                 datalen = revidx[1].offset - offset;
527                 if (!pack_to_stdout && p->index_version > 1 &&
528                     check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
529                         die("bad packed object CRC for %s", sha1_to_hex(entry->sha1));
530                 offset += entry->in_pack_header_size;
531                 datalen -= entry->in_pack_header_size;
532                 if (!pack_to_stdout && p->index_version == 1 &&
533                     check_pack_inflate(p, &w_curs, offset, datalen, entry->size))
534                         die("corrupt packed object for %s", sha1_to_hex(entry->sha1));
535                 copy_pack_data(f, p, &w_curs, offset, datalen);
536                 unuse_pack(&w_curs);
537                 reused++;
538         }
539         if (entry->delta)
540                 written_delta++;
541         written++;
542         if (!pack_to_stdout)
543                 entry->crc32 = crc32_end(f);
544         return hdrlen + datalen;
547 static off_t write_one(struct sha1file *f,
548                                struct object_entry *e,
549                                off_t offset)
551         unsigned long size;
553         /* offset is non zero if object is written already. */
554         if (e->offset || e->preferred_base)
555                 return offset;
557         /* if we are deltified, write out base object first. */
558         if (e->delta)
559                 offset = write_one(f, e->delta, offset);
561         e->offset = offset;
562         size = write_object(f, e);
564         /* make sure off_t is sufficiently large not to wrap */
565         if (offset > offset + size)
566                 die("pack too large for current definition of off_t");
567         return offset + size;
570 static int open_object_dir_tmp(const char *path)
572     snprintf(tmpname, sizeof(tmpname), "%s/%s", get_object_directory(), path);
573     return mkstemp(tmpname);
576 static off_t write_pack_file(void)
578         uint32_t i;
579         struct sha1file *f;
580         off_t offset, last_obj_offset = 0;
581         struct pack_header hdr;
582         int do_progress = progress;
584         if (pack_to_stdout) {
585                 f = sha1fd(1, "<stdout>");
586                 do_progress >>= 1;
587         } else {
588                 int fd = open_object_dir_tmp("tmp_pack_XXXXXX");
589                 if (fd < 0)
590                         die("unable to create %s: %s\n", tmpname, strerror(errno));
591                 pack_tmp_name = xstrdup(tmpname);
592                 f = sha1fd(fd, pack_tmp_name);
593         }
595         if (do_progress)
596                 start_progress(&progress_state, "Writing %u objects...", "", nr_result);
598         hdr.hdr_signature = htonl(PACK_SIGNATURE);
599         hdr.hdr_version = htonl(PACK_VERSION);
600         hdr.hdr_entries = htonl(nr_result);
601         sha1write(f, &hdr, sizeof(hdr));
602         offset = sizeof(hdr);
603         if (!nr_result)
604                 goto done;
605         for (i = 0; i < nr_objects; i++) {
606                 last_obj_offset = offset;
607                 offset = write_one(f, objects + i, offset);
608                 if (do_progress)
609                         display_progress(&progress_state, written);
610         }
611         if (do_progress)
612                 stop_progress(&progress_state);
613  done:
614         if (written != nr_result)
615                 die("wrote %u objects while expecting %u", written, nr_result);
616         sha1close(f, pack_file_sha1, 1);
618         return last_obj_offset;
621 static int sha1_sort(const void *_a, const void *_b)
623         const struct object_entry *a = *(struct object_entry **)_a;
624         const struct object_entry *b = *(struct object_entry **)_b;
625         return hashcmp(a->sha1, b->sha1);
628 static uint32_t index_default_version = 1;
629 static uint32_t index_off32_limit = 0x7fffffff;
631 static void write_index_file(off_t last_obj_offset, unsigned char *sha1)
633         struct sha1file *f;
634         struct object_entry **sorted_by_sha, **list, **last;
635         uint32_t array[256];
636         uint32_t i, index_version;
637         SHA_CTX ctx;
639         int fd = open_object_dir_tmp("tmp_idx_XXXXXX");
640         if (fd < 0)
641                 die("unable to create %s: %s\n", tmpname, strerror(errno));
642         idx_tmp_name = xstrdup(tmpname);
643         f = sha1fd(fd, idx_tmp_name);
645         if (nr_result) {
646                 uint32_t j = 0;
647                 sorted_by_sha =
648                         xcalloc(nr_result, sizeof(struct object_entry *));
649                 for (i = 0; i < nr_objects; i++)
650                         if (!objects[i].preferred_base)
651                                 sorted_by_sha[j++] = objects + i;
652                 if (j != nr_result)
653                         die("listed %u objects while expecting %u", j, nr_result);
654                 qsort(sorted_by_sha, nr_result, sizeof(*sorted_by_sha), sha1_sort);
655                 list = sorted_by_sha;
656                 last = sorted_by_sha + nr_result;
657         } else
658                 sorted_by_sha = list = last = NULL;
660         /* if last object's offset is >= 2^31 we should use index V2 */
661         index_version = (last_obj_offset >> 31) ? 2 : index_default_version;
663         /* index versions 2 and above need a header */
664         if (index_version >= 2) {
665                 struct pack_idx_header hdr;
666                 hdr.idx_signature = htonl(PACK_IDX_SIGNATURE);
667                 hdr.idx_version = htonl(index_version);
668                 sha1write(f, &hdr, sizeof(hdr));
669         }
671         /*
672          * Write the first-level table (the list is sorted,
673          * but we use a 256-entry lookup to be able to avoid
674          * having to do eight extra binary search iterations).
675          */
676         for (i = 0; i < 256; i++) {
677                 struct object_entry **next = list;
678                 while (next < last) {
679                         struct object_entry *entry = *next;
680                         if (entry->sha1[0] != i)
681                                 break;
682                         next++;
683                 }
684                 array[i] = htonl(next - sorted_by_sha);
685                 list = next;
686         }
687         sha1write(f, array, 256 * 4);
689         /* Compute the SHA1 hash of sorted object names. */
690         SHA1_Init(&ctx);
692         /* Write the actual SHA1 entries. */
693         list = sorted_by_sha;
694         for (i = 0; i < nr_result; i++) {
695                 struct object_entry *entry = *list++;
696                 if (index_version < 2) {
697                         uint32_t offset = htonl(entry->offset);
698                         sha1write(f, &offset, 4);
699                 }
700                 sha1write(f, entry->sha1, 20);
701                 SHA1_Update(&ctx, entry->sha1, 20);
702         }
704         if (index_version >= 2) {
705                 unsigned int nr_large_offset = 0;
707                 /* write the crc32 table */
708                 list = sorted_by_sha;
709                 for (i = 0; i < nr_objects; i++) {
710                         struct object_entry *entry = *list++;
711                         uint32_t crc32_val = htonl(entry->crc32);
712                         sha1write(f, &crc32_val, 4);
713                 }
715                 /* write the 32-bit offset table */
716                 list = sorted_by_sha;
717                 for (i = 0; i < nr_objects; i++) {
718                         struct object_entry *entry = *list++;
719                         uint32_t offset = (entry->offset <= index_off32_limit) ?
720                                 entry->offset : (0x80000000 | nr_large_offset++);
721                         offset = htonl(offset);
722                         sha1write(f, &offset, 4);
723                 }
725                 /* write the large offset table */
726                 list = sorted_by_sha;
727                 while (nr_large_offset) {
728                         struct object_entry *entry = *list++;
729                         uint64_t offset = entry->offset;
730                         if (offset > index_off32_limit) {
731                                 uint32_t split[2];
732                                 split[0]        = htonl(offset >> 32);
733                                 split[1] = htonl(offset & 0xffffffff);
734                                 sha1write(f, split, 8);
735                                 nr_large_offset--;
736                         }
737                 }
738         }
740         sha1write(f, pack_file_sha1, 20);
741         sha1close(f, NULL, 1);
742         free(sorted_by_sha);
743         SHA1_Final(sha1, &ctx);
746 static int locate_object_entry_hash(const unsigned char *sha1)
748         int i;
749         unsigned int ui;
750         memcpy(&ui, sha1, sizeof(unsigned int));
751         i = ui % object_ix_hashsz;
752         while (0 < object_ix[i]) {
753                 if (!hashcmp(sha1, objects[object_ix[i] - 1].sha1))
754                         return i;
755                 if (++i == object_ix_hashsz)
756                         i = 0;
757         }
758         return -1 - i;
761 static struct object_entry *locate_object_entry(const unsigned char *sha1)
763         int i;
765         if (!object_ix_hashsz)
766                 return NULL;
768         i = locate_object_entry_hash(sha1);
769         if (0 <= i)
770                 return &objects[object_ix[i]-1];
771         return NULL;
774 static void rehash_objects(void)
776         uint32_t i;
777         struct object_entry *oe;
779         object_ix_hashsz = nr_objects * 3;
780         if (object_ix_hashsz < 1024)
781                 object_ix_hashsz = 1024;
782         object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
783         memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
784         for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
785                 int ix = locate_object_entry_hash(oe->sha1);
786                 if (0 <= ix)
787                         continue;
788                 ix = -1 - ix;
789                 object_ix[ix] = i + 1;
790         }
793 static unsigned name_hash(const char *name)
795         unsigned char c;
796         unsigned hash = 0;
798         /*
799          * This effectively just creates a sortable number from the
800          * last sixteen non-whitespace characters. Last characters
801          * count "most", so things that end in ".c" sort together.
802          */
803         while ((c = *name++) != 0) {
804                 if (isspace(c))
805                         continue;
806                 hash = (hash >> 2) + (c << 24);
807         }
808         return hash;
811 static int add_object_entry(const unsigned char *sha1, enum object_type type,
812                             unsigned hash, int exclude)
814         struct object_entry *entry;
815         struct packed_git *p, *found_pack = NULL;
816         off_t found_offset = 0;
817         int ix;
819         ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
820         if (ix >= 0) {
821                 if (exclude) {
822                         entry = objects + object_ix[ix] - 1;
823                         if (!entry->preferred_base)
824                                 nr_result--;
825                         entry->preferred_base = 1;
826                 }
827                 return 0;
828         }
830         for (p = packed_git; p; p = p->next) {
831                 off_t offset = find_pack_entry_one(sha1, p);
832                 if (offset) {
833                         if (!found_pack) {
834                                 found_offset = offset;
835                                 found_pack = p;
836                         }
837                         if (exclude)
838                                 break;
839                         if (incremental)
840                                 return 0;
841                         if (local && !p->pack_local)
842                                 return 0;
843                 }
844         }
846         if (nr_objects >= nr_alloc) {
847                 nr_alloc = (nr_alloc  + 1024) * 3 / 2;
848                 objects = xrealloc(objects, nr_alloc * sizeof(*entry));
849         }
851         entry = objects + nr_objects++;
852         memset(entry, 0, sizeof(*entry));
853         hashcpy(entry->sha1, sha1);
854         entry->hash = hash;
855         if (type)
856                 entry->type = type;
857         if (exclude)
858                 entry->preferred_base = 1;
859         else
860                 nr_result++;
861         if (found_pack) {
862                 entry->in_pack = found_pack;
863                 entry->in_pack_offset = found_offset;
864         }
866         if (object_ix_hashsz * 3 <= nr_objects * 4)
867                 rehash_objects();
868         else
869                 object_ix[-1 - ix] = nr_objects;
871         if (progress)
872                 display_progress(&progress_state, nr_objects);
874         return 1;
877 struct pbase_tree_cache {
878         unsigned char sha1[20];
879         int ref;
880         int temporary;
881         void *tree_data;
882         unsigned long tree_size;
883 };
885 static struct pbase_tree_cache *(pbase_tree_cache[256]);
886 static int pbase_tree_cache_ix(const unsigned char *sha1)
888         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
890 static int pbase_tree_cache_ix_incr(int ix)
892         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
895 static struct pbase_tree {
896         struct pbase_tree *next;
897         /* This is a phony "cache" entry; we are not
898          * going to evict it nor find it through _get()
899          * mechanism -- this is for the toplevel node that
900          * would almost always change with any commit.
901          */
902         struct pbase_tree_cache pcache;
903 } *pbase_tree;
905 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
907         struct pbase_tree_cache *ent, *nent;
908         void *data;
909         unsigned long size;
910         enum object_type type;
911         int neigh;
912         int my_ix = pbase_tree_cache_ix(sha1);
913         int available_ix = -1;
915         /* pbase-tree-cache acts as a limited hashtable.
916          * your object will be found at your index or within a few
917          * slots after that slot if it is cached.
918          */
919         for (neigh = 0; neigh < 8; neigh++) {
920                 ent = pbase_tree_cache[my_ix];
921                 if (ent && !hashcmp(ent->sha1, sha1)) {
922                         ent->ref++;
923                         return ent;
924                 }
925                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
926                          ((0 <= available_ix) &&
927                           (!ent && pbase_tree_cache[available_ix])))
928                         available_ix = my_ix;
929                 if (!ent)
930                         break;
931                 my_ix = pbase_tree_cache_ix_incr(my_ix);
932         }
934         /* Did not find one.  Either we got a bogus request or
935          * we need to read and perhaps cache.
936          */
937         data = read_sha1_file(sha1, &type, &size);
938         if (!data)
939                 return NULL;
940         if (type != OBJ_TREE) {
941                 free(data);
942                 return NULL;
943         }
945         /* We need to either cache or return a throwaway copy */
947         if (available_ix < 0)
948                 ent = NULL;
949         else {
950                 ent = pbase_tree_cache[available_ix];
951                 my_ix = available_ix;
952         }
954         if (!ent) {
955                 nent = xmalloc(sizeof(*nent));
956                 nent->temporary = (available_ix < 0);
957         }
958         else {
959                 /* evict and reuse */
960                 free(ent->tree_data);
961                 nent = ent;
962         }
963         hashcpy(nent->sha1, sha1);
964         nent->tree_data = data;
965         nent->tree_size = size;
966         nent->ref = 1;
967         if (!nent->temporary)
968                 pbase_tree_cache[my_ix] = nent;
969         return nent;
972 static void pbase_tree_put(struct pbase_tree_cache *cache)
974         if (!cache->temporary) {
975                 cache->ref--;
976                 return;
977         }
978         free(cache->tree_data);
979         free(cache);
982 static int name_cmp_len(const char *name)
984         int i;
985         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
986                 ;
987         return i;
990 static void add_pbase_object(struct tree_desc *tree,
991                              const char *name,
992                              int cmplen,
993                              const char *fullname)
995         struct name_entry entry;
996         int cmp;
998         while (tree_entry(tree,&entry)) {
999                 cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
1000                       memcmp(name, entry.path, cmplen);
1001                 if (cmp > 0)
1002                         continue;
1003                 if (cmp < 0)
1004                         return;
1005                 if (name[cmplen] != '/') {
1006                         unsigned hash = name_hash(fullname);
1007                         add_object_entry(entry.sha1,
1008                                          S_ISDIR(entry.mode) ? OBJ_TREE : OBJ_BLOB,
1009                                          hash, 1);
1010                         return;
1011                 }
1012                 if (S_ISDIR(entry.mode)) {
1013                         struct tree_desc sub;
1014                         struct pbase_tree_cache *tree;
1015                         const char *down = name+cmplen+1;
1016                         int downlen = name_cmp_len(down);
1018                         tree = pbase_tree_get(entry.sha1);
1019                         if (!tree)
1020                                 return;
1021                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1023                         add_pbase_object(&sub, down, downlen, fullname);
1024                         pbase_tree_put(tree);
1025                 }
1026         }
1029 static unsigned *done_pbase_paths;
1030 static int done_pbase_paths_num;
1031 static int done_pbase_paths_alloc;
1032 static int done_pbase_path_pos(unsigned hash)
1034         int lo = 0;
1035         int hi = done_pbase_paths_num;
1036         while (lo < hi) {
1037                 int mi = (hi + lo) / 2;
1038                 if (done_pbase_paths[mi] == hash)
1039                         return mi;
1040                 if (done_pbase_paths[mi] < hash)
1041                         hi = mi;
1042                 else
1043                         lo = mi + 1;
1044         }
1045         return -lo-1;
1048 static int check_pbase_path(unsigned hash)
1050         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
1051         if (0 <= pos)
1052                 return 1;
1053         pos = -pos - 1;
1054         if (done_pbase_paths_alloc <= done_pbase_paths_num) {
1055                 done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
1056                 done_pbase_paths = xrealloc(done_pbase_paths,
1057                                             done_pbase_paths_alloc *
1058                                             sizeof(unsigned));
1059         }
1060         done_pbase_paths_num++;
1061         if (pos < done_pbase_paths_num)
1062                 memmove(done_pbase_paths + pos + 1,
1063                         done_pbase_paths + pos,
1064                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
1065         done_pbase_paths[pos] = hash;
1066         return 0;
1069 static void add_preferred_base_object(const char *name, unsigned hash)
1071         struct pbase_tree *it;
1072         int cmplen;
1074         if (!num_preferred_base || check_pbase_path(hash))
1075                 return;
1077         cmplen = name_cmp_len(name);
1078         for (it = pbase_tree; it; it = it->next) {
1079                 if (cmplen == 0) {
1080                         add_object_entry(it->pcache.sha1, OBJ_TREE, 0, 1);
1081                 }
1082                 else {
1083                         struct tree_desc tree;
1084                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1085                         add_pbase_object(&tree, name, cmplen, name);
1086                 }
1087         }
1090 static void add_preferred_base(unsigned char *sha1)
1092         struct pbase_tree *it;
1093         void *data;
1094         unsigned long size;
1095         unsigned char tree_sha1[20];
1097         if (window <= num_preferred_base++)
1098                 return;
1100         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
1101         if (!data)
1102                 return;
1104         for (it = pbase_tree; it; it = it->next) {
1105                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
1106                         free(data);
1107                         return;
1108                 }
1109         }
1111         it = xcalloc(1, sizeof(*it));
1112         it->next = pbase_tree;
1113         pbase_tree = it;
1115         hashcpy(it->pcache.sha1, tree_sha1);
1116         it->pcache.tree_data = data;
1117         it->pcache.tree_size = size;
1120 static void check_object(struct object_entry *entry)
1122         if (entry->in_pack) {
1123                 struct packed_git *p = entry->in_pack;
1124                 struct pack_window *w_curs = NULL;
1125                 const unsigned char *base_ref = NULL;
1126                 struct object_entry *base_entry;
1127                 unsigned long used, used_0;
1128                 unsigned int avail;
1129                 off_t ofs;
1130                 unsigned char *buf, c;
1132                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1134                 /*
1135                  * We want in_pack_type even if we do not reuse delta
1136                  * since non-delta representations could still be reused.
1137                  */
1138                 used = unpack_object_header_gently(buf, avail,
1139                                                    &entry->in_pack_type,
1140                                                    &entry->size);
1142                 /*
1143                  * Determine if this is a delta and if so whether we can
1144                  * reuse it or not.  Otherwise let's find out as cheaply as
1145                  * possible what the actual type and size for this object is.
1146                  */
1147                 switch (entry->in_pack_type) {
1148                 default:
1149                         /* Not a delta hence we've already got all we need. */
1150                         entry->type = entry->in_pack_type;
1151                         entry->in_pack_header_size = used;
1152                         unuse_pack(&w_curs);
1153                         return;
1154                 case OBJ_REF_DELTA:
1155                         if (!no_reuse_delta && !entry->preferred_base)
1156                                 base_ref = use_pack(p, &w_curs,
1157                                                 entry->in_pack_offset + used, NULL);
1158                         entry->in_pack_header_size = used + 20;
1159                         break;
1160                 case OBJ_OFS_DELTA:
1161                         buf = use_pack(p, &w_curs,
1162                                        entry->in_pack_offset + used, NULL);
1163                         used_0 = 0;
1164                         c = buf[used_0++];
1165                         ofs = c & 127;
1166                         while (c & 128) {
1167                                 ofs += 1;
1168                                 if (!ofs || MSB(ofs, 7))
1169                                         die("delta base offset overflow in pack for %s",
1170                                             sha1_to_hex(entry->sha1));
1171                                 c = buf[used_0++];
1172                                 ofs = (ofs << 7) + (c & 127);
1173                         }
1174                         if (ofs >= entry->in_pack_offset)
1175                                 die("delta base offset out of bound for %s",
1176                                     sha1_to_hex(entry->sha1));
1177                         ofs = entry->in_pack_offset - ofs;
1178                         if (!no_reuse_delta && !entry->preferred_base)
1179                                 base_ref = find_packed_object_name(p, ofs);
1180                         entry->in_pack_header_size = used + used_0;
1181                         break;
1182                 }
1184                 if (base_ref && (base_entry = locate_object_entry(base_ref))) {
1185                         /*
1186                          * If base_ref was set above that means we wish to
1187                          * reuse delta data, and we even found that base
1188                          * in the list of objects we want to pack. Goodie!
1189                          *
1190                          * Depth value does not matter - find_deltas() will
1191                          * never consider reused delta as the base object to
1192                          * deltify other objects against, in order to avoid
1193                          * circular deltas.
1194                          */
1195                         entry->type = entry->in_pack_type;
1196                         entry->delta = base_entry;
1197                         entry->delta_sibling = base_entry->delta_child;
1198                         base_entry->delta_child = entry;
1199                         unuse_pack(&w_curs);
1200                         return;
1201                 }
1203                 if (entry->type) {
1204                         /*
1205                          * This must be a delta and we already know what the
1206                          * final object type is.  Let's extract the actual
1207                          * object size from the delta header.
1208                          */
1209                         entry->size = get_size_from_delta(p, &w_curs,
1210                                         entry->in_pack_offset + entry->in_pack_header_size);
1211                         unuse_pack(&w_curs);
1212                         return;
1213                 }
1215                 /*
1216                  * No choice but to fall back to the recursive delta walk
1217                  * with sha1_object_info() to find about the object type
1218                  * at this point...
1219                  */
1220                 unuse_pack(&w_curs);
1221         }
1223         entry->type = sha1_object_info(entry->sha1, &entry->size);
1224         if (entry->type < 0)
1225                 die("unable to get type of object %s",
1226                     sha1_to_hex(entry->sha1));
1229 static int pack_offset_sort(const void *_a, const void *_b)
1231         const struct object_entry *a = *(struct object_entry **)_a;
1232         const struct object_entry *b = *(struct object_entry **)_b;
1234         /* avoid filesystem trashing with loose objects */
1235         if (!a->in_pack && !b->in_pack)
1236                 return hashcmp(a->sha1, b->sha1);
1238         if (a->in_pack < b->in_pack)
1239                 return -1;
1240         if (a->in_pack > b->in_pack)
1241                 return 1;
1242         return a->in_pack_offset < b->in_pack_offset ? -1 :
1243                         (a->in_pack_offset > b->in_pack_offset);
1246 static void get_object_details(void)
1248         uint32_t i;
1249         struct object_entry **sorted_by_offset;
1251         sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
1252         for (i = 0; i < nr_objects; i++)
1253                 sorted_by_offset[i] = objects + i;
1254         qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1256         prepare_pack_ix();
1257         for (i = 0; i < nr_objects; i++)
1258                 check_object(sorted_by_offset[i]);
1259         free(sorted_by_offset);
1262 static int type_size_sort(const void *_a, const void *_b)
1264         const struct object_entry *a = *(struct object_entry **)_a;
1265         const struct object_entry *b = *(struct object_entry **)_b;
1267         if (a->type < b->type)
1268                 return -1;
1269         if (a->type > b->type)
1270                 return 1;
1271         if (a->hash < b->hash)
1272                 return -1;
1273         if (a->hash > b->hash)
1274                 return 1;
1275         if (a->preferred_base < b->preferred_base)
1276                 return -1;
1277         if (a->preferred_base > b->preferred_base)
1278                 return 1;
1279         if (a->size < b->size)
1280                 return -1;
1281         if (a->size > b->size)
1282                 return 1;
1283         return a > b ? -1 : (a < b);  /* newest last */
1286 struct unpacked {
1287         struct object_entry *entry;
1288         void *data;
1289         struct delta_index *index;
1290 };
1292 /*
1293  * We search for deltas _backwards_ in a list sorted by type and
1294  * by size, so that we see progressively smaller and smaller files.
1295  * That's because we prefer deltas to be from the bigger file
1296  * to the smaller - deletes are potentially cheaper, but perhaps
1297  * more importantly, the bigger file is likely the more recent
1298  * one.
1299  */
1300 static int try_delta(struct unpacked *trg, struct unpacked *src,
1301                      unsigned max_depth)
1303         struct object_entry *trg_entry = trg->entry;
1304         struct object_entry *src_entry = src->entry;
1305         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1306         enum object_type type;
1307         void *delta_buf;
1309         /* Don't bother doing diffs between different types */
1310         if (trg_entry->type != src_entry->type)
1311                 return -1;
1313         /* We do not compute delta to *create* objects we are not
1314          * going to pack.
1315          */
1316         if (trg_entry->preferred_base)
1317                 return -1;
1319         /*
1320          * We do not bother to try a delta that we discarded
1321          * on an earlier try, but only when reusing delta data.
1322          */
1323         if (!no_reuse_delta && trg_entry->in_pack &&
1324             trg_entry->in_pack == src_entry->in_pack &&
1325             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1326             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1327                 return 0;
1329         /* Let's not bust the allowed depth. */
1330         if (src_entry->depth >= max_depth)
1331                 return 0;
1333         /* Now some size filtering heuristics. */
1334         trg_size = trg_entry->size;
1335         max_size = trg_size/2 - 20;
1336         max_size = max_size * (max_depth - src_entry->depth) / max_depth;
1337         if (max_size == 0)
1338                 return 0;
1339         if (trg_entry->delta && trg_entry->delta_size <= max_size)
1340                 max_size = trg_entry->delta_size-1;
1341         src_size = src_entry->size;
1342         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1343         if (sizediff >= max_size)
1344                 return 0;
1346         /* Load data if not already done */
1347         if (!trg->data) {
1348                 trg->data = read_sha1_file(trg_entry->sha1, &type, &sz);
1349                 if (sz != trg_size)
1350                         die("object %s inconsistent object length (%lu vs %lu)",
1351                             sha1_to_hex(trg_entry->sha1), sz, trg_size);
1352         }
1353         if (!src->data) {
1354                 src->data = read_sha1_file(src_entry->sha1, &type, &sz);
1355                 if (sz != src_size)
1356                         die("object %s inconsistent object length (%lu vs %lu)",
1357                             sha1_to_hex(src_entry->sha1), sz, src_size);
1358         }
1359         if (!src->index) {
1360                 src->index = create_delta_index(src->data, src_size);
1361                 if (!src->index)
1362                         die("out of memory");
1363         }
1365         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1366         if (!delta_buf)
1367                 return 0;
1369         trg_entry->delta = src_entry;
1370         trg_entry->delta_size = delta_size;
1371         trg_entry->depth = src_entry->depth + 1;
1372         free(delta_buf);
1373         return 1;
1376 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1378         struct object_entry *child = me->delta_child;
1379         unsigned int m = n;
1380         while (child) {
1381                 unsigned int c = check_delta_limit(child, n + 1);
1382                 if (m < c)
1383                         m = c;
1384                 child = child->delta_sibling;
1385         }
1386         return m;
1389 static void find_deltas(struct object_entry **list, int window, int depth)
1391         uint32_t i = nr_objects, idx = 0, processed = 0;
1392         unsigned int array_size = window * sizeof(struct unpacked);
1393         struct unpacked *array;
1394         int max_depth;
1396         if (!nr_objects)
1397                 return;
1398         array = xmalloc(array_size);
1399         memset(array, 0, array_size);
1400         if (progress)
1401                 start_progress(&progress_state, "Deltifying %u objects...", "", nr_result);
1403         do {
1404                 struct object_entry *entry = list[--i];
1405                 struct unpacked *n = array + idx;
1406                 int j;
1408                 if (!entry->preferred_base)
1409                         processed++;
1411                 if (progress)
1412                         display_progress(&progress_state, processed);
1414                 if (entry->delta)
1415                         /* This happens if we decided to reuse existing
1416                          * delta from a pack.  "!no_reuse_delta &&" is implied.
1417                          */
1418                         continue;
1420                 if (entry->size < 50)
1421                         continue;
1422                 free_delta_index(n->index);
1423                 n->index = NULL;
1424                 free(n->data);
1425                 n->data = NULL;
1426                 n->entry = entry;
1428                 /*
1429                  * If the current object is at pack edge, take the depth the
1430                  * objects that depend on the current object into account
1431                  * otherwise they would become too deep.
1432                  */
1433                 max_depth = depth;
1434                 if (entry->delta_child) {
1435                         max_depth -= check_delta_limit(entry, 0);
1436                         if (max_depth <= 0)
1437                                 goto next;
1438                 }
1440                 j = window;
1441                 while (--j > 0) {
1442                         uint32_t other_idx = idx + j;
1443                         struct unpacked *m;
1444                         if (other_idx >= window)
1445                                 other_idx -= window;
1446                         m = array + other_idx;
1447                         if (!m->entry)
1448                                 break;
1449                         if (try_delta(n, m, max_depth) < 0)
1450                                 break;
1451                 }
1453                 /* if we made n a delta, and if n is already at max
1454                  * depth, leaving it in the window is pointless.  we
1455                  * should evict it first.
1456                  */
1457                 if (entry->delta && depth <= entry->depth)
1458                         continue;
1460                 next:
1461                 idx++;
1462                 if (idx >= window)
1463                         idx = 0;
1464         } while (i > 0);
1466         if (progress)
1467                 stop_progress(&progress_state);
1469         for (i = 0; i < window; ++i) {
1470                 free_delta_index(array[i].index);
1471                 free(array[i].data);
1472         }
1473         free(array);
1476 static void prepare_pack(int window, int depth)
1478         struct object_entry **delta_list;
1479         uint32_t i;
1481         get_object_details();
1483         if (!window || !depth)
1484                 return;
1486         delta_list = xmalloc(nr_objects * sizeof(*delta_list));
1487         for (i = 0; i < nr_objects; i++)
1488                 delta_list[i] = objects + i;
1489         qsort(delta_list, nr_objects, sizeof(*delta_list), type_size_sort);
1490         find_deltas(delta_list, window+1, depth);
1491         free(delta_list);
1494 static int git_pack_config(const char *k, const char *v)
1496         if(!strcmp(k, "pack.window")) {
1497                 window = git_config_int(k, v);
1498                 return 0;
1499         }
1500         if(!strcmp(k, "pack.depth")) {
1501                 depth = git_config_int(k, v);
1502                 return 0;
1503         }
1504         if (!strcmp(k, "pack.compression")) {
1505                 int level = git_config_int(k, v);
1506                 if (level == -1)
1507                         level = Z_DEFAULT_COMPRESSION;
1508                 else if (level < 0 || level > Z_BEST_COMPRESSION)
1509                         die("bad pack compression level %d", level);
1510                 pack_compression_level = level;
1511                 pack_compression_seen = 1;
1512                 return 0;
1513         }
1514         return git_default_config(k, v);
1517 static void read_object_list_from_stdin(void)
1519         char line[40 + 1 + PATH_MAX + 2];
1520         unsigned char sha1[20];
1521         unsigned hash;
1523         for (;;) {
1524                 if (!fgets(line, sizeof(line), stdin)) {
1525                         if (feof(stdin))
1526                                 break;
1527                         if (!ferror(stdin))
1528                                 die("fgets returned NULL, not EOF, not error!");
1529                         if (errno != EINTR)
1530                                 die("fgets: %s", strerror(errno));
1531                         clearerr(stdin);
1532                         continue;
1533                 }
1534                 if (line[0] == '-') {
1535                         if (get_sha1_hex(line+1, sha1))
1536                                 die("expected edge sha1, got garbage:\n %s",
1537                                     line);
1538                         add_preferred_base(sha1);
1539                         continue;
1540                 }
1541                 if (get_sha1_hex(line, sha1))
1542                         die("expected sha1, got garbage:\n %s", line);
1544                 hash = name_hash(line+41);
1545                 add_preferred_base_object(line+41, hash);
1546                 add_object_entry(sha1, 0, hash, 0);
1547         }
1550 static void show_commit(struct commit *commit)
1552         add_object_entry(commit->object.sha1, OBJ_COMMIT, 0, 0);
1555 static void show_object(struct object_array_entry *p)
1557         unsigned hash = name_hash(p->name);
1558         add_preferred_base_object(p->name, hash);
1559         add_object_entry(p->item->sha1, p->item->type, hash, 0);
1562 static void show_edge(struct commit *commit)
1564         add_preferred_base(commit->object.sha1);
1567 static void get_object_list(int ac, const char **av)
1569         struct rev_info revs;
1570         char line[1000];
1571         int flags = 0;
1573         init_revisions(&revs, NULL);
1574         save_commit_buffer = 0;
1575         track_object_refs = 0;
1576         setup_revisions(ac, av, &revs, NULL);
1578         while (fgets(line, sizeof(line), stdin) != NULL) {
1579                 int len = strlen(line);
1580                 if (line[len - 1] == '\n')
1581                         line[--len] = 0;
1582                 if (!len)
1583                         break;
1584                 if (*line == '-') {
1585                         if (!strcmp(line, "--not")) {
1586                                 flags ^= UNINTERESTING;
1587                                 continue;
1588                         }
1589                         die("not a rev '%s'", line);
1590                 }
1591                 if (handle_revision_arg(line, &revs, flags, 1))
1592                         die("bad revision '%s'", line);
1593         }
1595         prepare_revision_walk(&revs);
1596         mark_edges_uninteresting(revs.commits, &revs, show_edge);
1597         traverse_commit_list(&revs, show_commit, show_object);
1600 static int adjust_perm(const char *path, mode_t mode)
1602         if (chmod(path, mode))
1603                 return -1;
1604         return adjust_shared_perm(path);
1607 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
1609         int use_internal_rev_list = 0;
1610         int thin = 0;
1611         uint32_t i;
1612         off_t last_obj_offset;
1613         const char *base_name = NULL;
1614         const char **rp_av;
1615         int rp_ac_alloc = 64;
1616         int rp_ac;
1618         rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
1620         rp_av[0] = "pack-objects";
1621         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
1622         rp_ac = 2;
1624         git_config(git_pack_config);
1625         if (!pack_compression_seen && core_compression_seen)
1626                 pack_compression_level = core_compression_level;
1628         progress = isatty(2);
1629         for (i = 1; i < argc; i++) {
1630                 const char *arg = argv[i];
1632                 if (*arg != '-')
1633                         break;
1635                 if (!strcmp("--non-empty", arg)) {
1636                         non_empty = 1;
1637                         continue;
1638                 }
1639                 if (!strcmp("--local", arg)) {
1640                         local = 1;
1641                         continue;
1642                 }
1643                 if (!strcmp("--incremental", arg)) {
1644                         incremental = 1;
1645                         continue;
1646                 }
1647                 if (!prefixcmp(arg, "--compression=")) {
1648                         char *end;
1649                         int level = strtoul(arg+14, &end, 0);
1650                         if (!arg[14] || *end)
1651                                 usage(pack_usage);
1652                         if (level == -1)
1653                                 level = Z_DEFAULT_COMPRESSION;
1654                         else if (level < 0 || level > Z_BEST_COMPRESSION)
1655                                 die("bad pack compression level %d", level);
1656                         pack_compression_level = level;
1657                         continue;
1658                 }
1659                 if (!prefixcmp(arg, "--window=")) {
1660                         char *end;
1661                         window = strtoul(arg+9, &end, 0);
1662                         if (!arg[9] || *end)
1663                                 usage(pack_usage);
1664                         continue;
1665                 }
1666                 if (!prefixcmp(arg, "--depth=")) {
1667                         char *end;
1668                         depth = strtoul(arg+8, &end, 0);
1669                         if (!arg[8] || *end)
1670                                 usage(pack_usage);
1671                         continue;
1672                 }
1673                 if (!strcmp("--progress", arg)) {
1674                         progress = 1;
1675                         continue;
1676                 }
1677                 if (!strcmp("--all-progress", arg)) {
1678                         progress = 2;
1679                         continue;
1680                 }
1681                 if (!strcmp("-q", arg)) {
1682                         progress = 0;
1683                         continue;
1684                 }
1685                 if (!strcmp("--no-reuse-delta", arg)) {
1686                         no_reuse_delta = 1;
1687                         continue;
1688                 }
1689                 if (!strcmp("--no-reuse-object", arg)) {
1690                         no_reuse_object = no_reuse_delta = 1;
1691                         continue;
1692                 }
1693                 if (!strcmp("--delta-base-offset", arg)) {
1694                         allow_ofs_delta = 1;
1695                         continue;
1696                 }
1697                 if (!strcmp("--stdout", arg)) {
1698                         pack_to_stdout = 1;
1699                         continue;
1700                 }
1701                 if (!strcmp("--revs", arg)) {
1702                         use_internal_rev_list = 1;
1703                         continue;
1704                 }
1705                 if (!strcmp("--unpacked", arg) ||
1706                     !prefixcmp(arg, "--unpacked=") ||
1707                     !strcmp("--reflog", arg) ||
1708                     !strcmp("--all", arg)) {
1709                         use_internal_rev_list = 1;
1710                         if (rp_ac >= rp_ac_alloc - 1) {
1711                                 rp_ac_alloc = alloc_nr(rp_ac_alloc);
1712                                 rp_av = xrealloc(rp_av,
1713                                                  rp_ac_alloc * sizeof(*rp_av));
1714                         }
1715                         rp_av[rp_ac++] = arg;
1716                         continue;
1717                 }
1718                 if (!strcmp("--thin", arg)) {
1719                         use_internal_rev_list = 1;
1720                         thin = 1;
1721                         rp_av[1] = "--objects-edge";
1722                         continue;
1723                 }
1724                 if (!prefixcmp(arg, "--index-version=")) {
1725                         char *c;
1726                         index_default_version = strtoul(arg + 16, &c, 10);
1727                         if (index_default_version > 2)
1728                                 die("bad %s", arg);
1729                         if (*c == ',')
1730                                 index_off32_limit = strtoul(c+1, &c, 0);
1731                         if (*c || index_off32_limit & 0x80000000)
1732                                 die("bad %s", arg);
1733                         continue;
1734                 }
1735                 usage(pack_usage);
1736         }
1738         /* Traditionally "pack-objects [options] base extra" failed;
1739          * we would however want to take refs parameter that would
1740          * have been given to upstream rev-list ourselves, which means
1741          * we somehow want to say what the base name is.  So the
1742          * syntax would be:
1743          *
1744          * pack-objects [options] base <refs...>
1745          *
1746          * in other words, we would treat the first non-option as the
1747          * base_name and send everything else to the internal revision
1748          * walker.
1749          */
1751         if (!pack_to_stdout)
1752                 base_name = argv[i++];
1754         if (pack_to_stdout != !base_name)
1755                 usage(pack_usage);
1757         if (!pack_to_stdout && thin)
1758                 die("--thin cannot be used to build an indexable pack.");
1760         prepare_packed_git();
1762         if (progress)
1763                 start_progress(&progress_state, "Generating pack...",
1764                                "Counting objects: ", 0);
1765         if (!use_internal_rev_list)
1766                 read_object_list_from_stdin();
1767         else {
1768                 rp_av[rp_ac] = NULL;
1769                 get_object_list(rp_ac, rp_av);
1770         }
1771         if (progress) {
1772                 stop_progress(&progress_state);
1773                 fprintf(stderr, "Done counting %u objects.\n", nr_objects);
1774         }
1776         if (non_empty && !nr_result)
1777                 return 0;
1778         if (progress && (nr_objects != nr_result))
1779                 fprintf(stderr, "Result has %u objects.\n", nr_result);
1780         if (nr_result)
1781                 prepare_pack(window, depth);
1782         last_obj_offset = write_pack_file();
1783         if (!pack_to_stdout) {
1784                 unsigned char object_list_sha1[20];
1785                 mode_t mode = umask(0);
1787                 umask(mode);
1788                 mode = 0444 & ~mode;
1790                 write_index_file(last_obj_offset, object_list_sha1);
1791                 snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
1792                          base_name, sha1_to_hex(object_list_sha1));
1793                 if (adjust_perm(pack_tmp_name, mode))
1794                         die("unable to make temporary pack file readable: %s",
1795                             strerror(errno));
1796                 if (rename(pack_tmp_name, tmpname))
1797                         die("unable to rename temporary pack file: %s",
1798                             strerror(errno));
1799                 snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
1800                          base_name, sha1_to_hex(object_list_sha1));
1801                 if (adjust_perm(idx_tmp_name, mode))
1802                         die("unable to make temporary index file readable: %s",
1803                             strerror(errno));
1804                 if (rename(idx_tmp_name, tmpname))
1805                         die("unable to rename temporary index file: %s",
1806                             strerror(errno));
1807                 puts(sha1_to_hex(object_list_sha1));
1808         }
1809         if (progress)
1810                 fprintf(stderr, "Total %u (delta %u), reused %u (delta %u)\n",
1811                         written, written_delta, reused, reused_delta);
1812         return 0;