Merge branch 'nd/versioncmp-prereleases'
[git] / builtin / pack-objects.c
1 #include "builtin.h"
2 #include "cache.h"
3 #include "attr.h"
4 #include "object.h"
5 #include "blob.h"
6 #include "commit.h"
7 #include "tag.h"
8 #include "tree.h"
9 #include "delta.h"
10 #include "pack.h"
11 #include "pack-revindex.h"
12 #include "csum-file.h"
13 #include "tree-walk.h"
14 #include "diff.h"
15 #include "revision.h"
16 #include "list-objects.h"
17 #include "pack-objects.h"
18 #include "progress.h"
19 #include "refs.h"
20 #include "streaming.h"
21 #include "thread-utils.h"
22 #include "pack-bitmap.h"
23 #include "reachable.h"
24 #include "sha1-array.h"
25 #include "argv-array.h"
26
27 static const char *pack_usage[] = {
28         N_("git pack-objects --stdout [options...] [< ref-list | < object-list]"),
29         N_("git pack-objects [options...] base-name [< ref-list | < object-list]"),
30         NULL
31 };
32
33 /*
34  * Objects we are going to pack are collected in the `to_pack` structure.
35  * It contains an array (dynamically expanded) of the object data, and a map
36  * that can resolve SHA1s to their position in the array.
37  */
38 static struct packing_data to_pack;
39
40 static struct pack_idx_entry **written_list;
41 static uint32_t nr_result, nr_written;
42
43 static int non_empty;
44 static int reuse_delta = 1, reuse_object = 1;
45 static int keep_unreachable, unpack_unreachable, include_tag;
46 static unsigned long unpack_unreachable_expiration;
47 static int local;
48 static int incremental;
49 static int ignore_packed_keep;
50 static int allow_ofs_delta;
51 static struct pack_idx_option pack_idx_opts;
52 static const char *base_name;
53 static int progress = 1;
54 static int window = 10;
55 static unsigned long pack_size_limit;
56 static int depth = 50;
57 static int delta_search_threads;
58 static int pack_to_stdout;
59 static int num_preferred_base;
60 static struct progress *progress_state;
61 static int pack_compression_level = Z_DEFAULT_COMPRESSION;
62 static int pack_compression_seen;
63
64 static struct packed_git *reuse_packfile;
65 static uint32_t reuse_packfile_objects;
66 static off_t reuse_packfile_offset;
67
68 static int use_bitmap_index = 1;
69 static int write_bitmap_index;
70 static uint16_t write_bitmap_options;
71
72 static unsigned long delta_cache_size = 0;
73 static unsigned long max_delta_cache_size = 256 * 1024 * 1024;
74 static unsigned long cache_max_small_delta_size = 1000;
75
76 static unsigned long window_memory_limit = 0;
77
78 /*
79  * stats
80  */
81 static uint32_t written, written_delta;
82 static uint32_t reused, reused_delta;
83
84 /*
85  * Indexed commits
86  */
87 static struct commit **indexed_commits;
88 static unsigned int indexed_commits_nr;
89 static unsigned int indexed_commits_alloc;
90
91 static void index_commit_for_bitmap(struct commit *commit)
92 {
93         if (indexed_commits_nr >= indexed_commits_alloc) {
94                 indexed_commits_alloc = (indexed_commits_alloc + 32) * 2;
95                 REALLOC_ARRAY(indexed_commits, indexed_commits_alloc);
96         }
97
98         indexed_commits[indexed_commits_nr++] = commit;
99 }
100
101 static void *get_delta(struct object_entry *entry)
102 {
103         unsigned long size, base_size, delta_size;
104         void *buf, *base_buf, *delta_buf;
105         enum object_type type;
106
107         buf = read_sha1_file(entry->idx.sha1, &type, &size);
108         if (!buf)
109                 die("unable to read %s", sha1_to_hex(entry->idx.sha1));
110         base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
111         if (!base_buf)
112                 die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
113         delta_buf = diff_delta(base_buf, base_size,
114                                buf, size, &delta_size, 0);
115         if (!delta_buf || delta_size != entry->delta_size)
116                 die("delta size changed");
117         free(buf);
118         free(base_buf);
119         return delta_buf;
120 }
121
122 static unsigned long do_compress(void **pptr, unsigned long size)
123 {
124         git_zstream stream;
125         void *in, *out;
126         unsigned long maxsize;
127
128         git_deflate_init(&stream, pack_compression_level);
129         maxsize = git_deflate_bound(&stream, size);
130
131         in = *pptr;
132         out = xmalloc(maxsize);
133         *pptr = out;
134
135         stream.next_in = in;
136         stream.avail_in = size;
137         stream.next_out = out;
138         stream.avail_out = maxsize;
139         while (git_deflate(&stream, Z_FINISH) == Z_OK)
140                 ; /* nothing */
141         git_deflate_end(&stream);
142
143         free(in);
144         return stream.total_out;
145 }
146
147 static unsigned long write_large_blob_data(struct git_istream *st, struct sha1file *f,
148                                            const unsigned char *sha1)
149 {
150         git_zstream stream;
151         unsigned char ibuf[1024 * 16];
152         unsigned char obuf[1024 * 16];
153         unsigned long olen = 0;
154
155         git_deflate_init(&stream, pack_compression_level);
156
157         for (;;) {
158                 ssize_t readlen;
159                 int zret = Z_OK;
160                 readlen = read_istream(st, ibuf, sizeof(ibuf));
161                 if (readlen == -1)
162                         die(_("unable to read %s"), sha1_to_hex(sha1));
163
164                 stream.next_in = ibuf;
165                 stream.avail_in = readlen;
166                 while ((stream.avail_in || readlen == 0) &&
167                        (zret == Z_OK || zret == Z_BUF_ERROR)) {
168                         stream.next_out = obuf;
169                         stream.avail_out = sizeof(obuf);
170                         zret = git_deflate(&stream, readlen ? 0 : Z_FINISH);
171                         sha1write(f, obuf, stream.next_out - obuf);
172                         olen += stream.next_out - obuf;
173                 }
174                 if (stream.avail_in)
175                         die(_("deflate error (%d)"), zret);
176                 if (readlen == 0) {
177                         if (zret != Z_STREAM_END)
178                                 die(_("deflate error (%d)"), zret);
179                         break;
180                 }
181         }
182         git_deflate_end(&stream);
183         return olen;
184 }
185
186 /*
187  * we are going to reuse the existing object data as is.  make
188  * sure it is not corrupt.
189  */
190 static int check_pack_inflate(struct packed_git *p,
191                 struct pack_window **w_curs,
192                 off_t offset,
193                 off_t len,
194                 unsigned long expect)
195 {
196         git_zstream stream;
197         unsigned char fakebuf[4096], *in;
198         int st;
199
200         memset(&stream, 0, sizeof(stream));
201         git_inflate_init(&stream);
202         do {
203                 in = use_pack(p, w_curs, offset, &stream.avail_in);
204                 stream.next_in = in;
205                 stream.next_out = fakebuf;
206                 stream.avail_out = sizeof(fakebuf);
207                 st = git_inflate(&stream, Z_FINISH);
208                 offset += stream.next_in - in;
209         } while (st == Z_OK || st == Z_BUF_ERROR);
210         git_inflate_end(&stream);
211         return (st == Z_STREAM_END &&
212                 stream.total_out == expect &&
213                 stream.total_in == len) ? 0 : -1;
214 }
215
216 static void copy_pack_data(struct sha1file *f,
217                 struct packed_git *p,
218                 struct pack_window **w_curs,
219                 off_t offset,
220                 off_t len)
221 {
222         unsigned char *in;
223         unsigned long avail;
224
225         while (len) {
226                 in = use_pack(p, w_curs, offset, &avail);
227                 if (avail > len)
228                         avail = (unsigned long)len;
229                 sha1write(f, in, avail);
230                 offset += avail;
231                 len -= avail;
232         }
233 }
234
235 /* Return 0 if we will bust the pack-size limit */
236 static unsigned long write_no_reuse_object(struct sha1file *f, struct object_entry *entry,
237                                            unsigned long limit, int usable_delta)
238 {
239         unsigned long size, datalen;
240         unsigned char header[10], dheader[10];
241         unsigned hdrlen;
242         enum object_type type;
243         void *buf;
244         struct git_istream *st = NULL;
245
246         if (!usable_delta) {
247                 if (entry->type == OBJ_BLOB &&
248                     entry->size > big_file_threshold &&
249                     (st = open_istream(entry->idx.sha1, &type, &size, NULL)) != NULL)
250                         buf = NULL;
251                 else {
252                         buf = read_sha1_file(entry->idx.sha1, &type, &size);
253                         if (!buf)
254                                 die(_("unable to read %s"), sha1_to_hex(entry->idx.sha1));
255                 }
256                 /*
257                  * make sure no cached delta data remains from a
258                  * previous attempt before a pack split occurred.
259                  */
260                 free(entry->delta_data);
261                 entry->delta_data = NULL;
262                 entry->z_delta_size = 0;
263         } else if (entry->delta_data) {
264                 size = entry->delta_size;
265                 buf = entry->delta_data;
266                 entry->delta_data = NULL;
267                 type = (allow_ofs_delta && entry->delta->idx.offset) ?
268                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
269         } else {
270                 buf = get_delta(entry);
271                 size = entry->delta_size;
272                 type = (allow_ofs_delta && entry->delta->idx.offset) ?
273                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
274         }
275
276         if (st) /* large blob case, just assume we don't compress well */
277                 datalen = size;
278         else if (entry->z_delta_size)
279                 datalen = entry->z_delta_size;
280         else
281                 datalen = do_compress(&buf, size);
282
283         /*
284          * The object header is a byte of 'type' followed by zero or
285          * more bytes of length.
286          */
287         hdrlen = encode_in_pack_object_header(type, size, header);
288
289         if (type == OBJ_OFS_DELTA) {
290                 /*
291                  * Deltas with relative base contain an additional
292                  * encoding of the relative offset for the delta
293                  * base from this object's position in the pack.
294                  */
295                 off_t ofs = entry->idx.offset - entry->delta->idx.offset;
296                 unsigned pos = sizeof(dheader) - 1;
297                 dheader[pos] = ofs & 127;
298                 while (ofs >>= 7)
299                         dheader[--pos] = 128 | (--ofs & 127);
300                 if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
301                         if (st)
302                                 close_istream(st);
303                         free(buf);
304                         return 0;
305                 }
306                 sha1write(f, header, hdrlen);
307                 sha1write(f, dheader + pos, sizeof(dheader) - pos);
308                 hdrlen += sizeof(dheader) - pos;
309         } else if (type == OBJ_REF_DELTA) {
310                 /*
311                  * Deltas with a base reference contain
312                  * an additional 20 bytes for the base sha1.
313                  */
314                 if (limit && hdrlen + 20 + datalen + 20 >= limit) {
315                         if (st)
316                                 close_istream(st);
317                         free(buf);
318                         return 0;
319                 }
320                 sha1write(f, header, hdrlen);
321                 sha1write(f, entry->delta->idx.sha1, 20);
322                 hdrlen += 20;
323         } else {
324                 if (limit && hdrlen + datalen + 20 >= limit) {
325                         if (st)
326                                 close_istream(st);
327                         free(buf);
328                         return 0;
329                 }
330                 sha1write(f, header, hdrlen);
331         }
332         if (st) {
333                 datalen = write_large_blob_data(st, f, entry->idx.sha1);
334                 close_istream(st);
335         } else {
336                 sha1write(f, buf, datalen);
337                 free(buf);
338         }
339
340         return hdrlen + datalen;
341 }
342
343 /* Return 0 if we will bust the pack-size limit */
344 static unsigned long write_reuse_object(struct sha1file *f, struct object_entry *entry,
345                                         unsigned long limit, int usable_delta)
346 {
347         struct packed_git *p = entry->in_pack;
348         struct pack_window *w_curs = NULL;
349         struct revindex_entry *revidx;
350         off_t offset;
351         enum object_type type = entry->type;
352         unsigned long datalen;
353         unsigned char header[10], dheader[10];
354         unsigned hdrlen;
355
356         if (entry->delta)
357                 type = (allow_ofs_delta && entry->delta->idx.offset) ?
358                         OBJ_OFS_DELTA : OBJ_REF_DELTA;
359         hdrlen = encode_in_pack_object_header(type, entry->size, header);
360
361         offset = entry->in_pack_offset;
362         revidx = find_pack_revindex(p, offset);
363         datalen = revidx[1].offset - offset;
364         if (!pack_to_stdout && p->index_version > 1 &&
365             check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
366                 error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
367                 unuse_pack(&w_curs);
368                 return write_no_reuse_object(f, entry, limit, usable_delta);
369         }
370
371         offset += entry->in_pack_header_size;
372         datalen -= entry->in_pack_header_size;
373
374         if (!pack_to_stdout && p->index_version == 1 &&
375             check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
376                 error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
377                 unuse_pack(&w_curs);
378                 return write_no_reuse_object(f, entry, limit, usable_delta);
379         }
380
381         if (type == OBJ_OFS_DELTA) {
382                 off_t ofs = entry->idx.offset - entry->delta->idx.offset;
383                 unsigned pos = sizeof(dheader) - 1;
384                 dheader[pos] = ofs & 127;
385                 while (ofs >>= 7)
386                         dheader[--pos] = 128 | (--ofs & 127);
387                 if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
388                         unuse_pack(&w_curs);
389                         return 0;
390                 }
391                 sha1write(f, header, hdrlen);
392                 sha1write(f, dheader + pos, sizeof(dheader) - pos);
393                 hdrlen += sizeof(dheader) - pos;
394                 reused_delta++;
395         } else if (type == OBJ_REF_DELTA) {
396                 if (limit && hdrlen + 20 + datalen + 20 >= limit) {
397                         unuse_pack(&w_curs);
398                         return 0;
399                 }
400                 sha1write(f, header, hdrlen);
401                 sha1write(f, entry->delta->idx.sha1, 20);
402                 hdrlen += 20;
403                 reused_delta++;
404         } else {
405                 if (limit && hdrlen + datalen + 20 >= limit) {
406                         unuse_pack(&w_curs);
407                         return 0;
408                 }
409                 sha1write(f, header, hdrlen);
410         }
411         copy_pack_data(f, p, &w_curs, offset, datalen);
412         unuse_pack(&w_curs);
413         reused++;
414         return hdrlen + datalen;
415 }
416
417 /* Return 0 if we will bust the pack-size limit */
418 static unsigned long write_object(struct sha1file *f,
419                                   struct object_entry *entry,
420                                   off_t write_offset)
421 {
422         unsigned long limit, len;
423         int usable_delta, to_reuse;
424
425         if (!pack_to_stdout)
426                 crc32_begin(f);
427
428         /* apply size limit if limited packsize and not first object */
429         if (!pack_size_limit || !nr_written)
430                 limit = 0;
431         else if (pack_size_limit <= write_offset)
432                 /*
433                  * the earlier object did not fit the limit; avoid
434                  * mistaking this with unlimited (i.e. limit = 0).
435                  */
436                 limit = 1;
437         else
438                 limit = pack_size_limit - write_offset;
439
440         if (!entry->delta)
441                 usable_delta = 0;       /* no delta */
442         else if (!pack_size_limit)
443                usable_delta = 1;        /* unlimited packfile */
444         else if (entry->delta->idx.offset == (off_t)-1)
445                 usable_delta = 0;       /* base was written to another pack */
446         else if (entry->delta->idx.offset)
447                 usable_delta = 1;       /* base already exists in this pack */
448         else
449                 usable_delta = 0;       /* base could end up in another pack */
450
451         if (!reuse_object)
452                 to_reuse = 0;   /* explicit */
453         else if (!entry->in_pack)
454                 to_reuse = 0;   /* can't reuse what we don't have */
455         else if (entry->type == OBJ_REF_DELTA || entry->type == OBJ_OFS_DELTA)
456                                 /* check_object() decided it for us ... */
457                 to_reuse = usable_delta;
458                                 /* ... but pack split may override that */
459         else if (entry->type != entry->in_pack_type)
460                 to_reuse = 0;   /* pack has delta which is unusable */
461         else if (entry->delta)
462                 to_reuse = 0;   /* we want to pack afresh */
463         else
464                 to_reuse = 1;   /* we have it in-pack undeltified,
465                                  * and we do not need to deltify it.
466                                  */
467
468         if (!to_reuse)
469                 len = write_no_reuse_object(f, entry, limit, usable_delta);
470         else
471                 len = write_reuse_object(f, entry, limit, usable_delta);
472         if (!len)
473                 return 0;
474
475         if (usable_delta)
476                 written_delta++;
477         written++;
478         if (!pack_to_stdout)
479                 entry->idx.crc32 = crc32_end(f);
480         return len;
481 }
482
483 enum write_one_status {
484         WRITE_ONE_SKIP = -1, /* already written */
485         WRITE_ONE_BREAK = 0, /* writing this will bust the limit; not written */
486         WRITE_ONE_WRITTEN = 1, /* normal */
487         WRITE_ONE_RECURSIVE = 2 /* already scheduled to be written */
488 };
489
490 static enum write_one_status write_one(struct sha1file *f,
491                                        struct object_entry *e,
492                                        off_t *offset)
493 {
494         unsigned long size;
495         int recursing;
496
497         /*
498          * we set offset to 1 (which is an impossible value) to mark
499          * the fact that this object is involved in "write its base
500          * first before writing a deltified object" recursion.
501          */
502         recursing = (e->idx.offset == 1);
503         if (recursing) {
504                 warning("recursive delta detected for object %s",
505                         sha1_to_hex(e->idx.sha1));
506                 return WRITE_ONE_RECURSIVE;
507         } else if (e->idx.offset || e->preferred_base) {
508                 /* offset is non zero if object is written already. */
509                 return WRITE_ONE_SKIP;
510         }
511
512         /* if we are deltified, write out base object first. */
513         if (e->delta) {
514                 e->idx.offset = 1; /* now recurse */
515                 switch (write_one(f, e->delta, offset)) {
516                 case WRITE_ONE_RECURSIVE:
517                         /* we cannot depend on this one */
518                         e->delta = NULL;
519                         break;
520                 default:
521                         break;
522                 case WRITE_ONE_BREAK:
523                         e->idx.offset = recursing;
524                         return WRITE_ONE_BREAK;
525                 }
526         }
527
528         e->idx.offset = *offset;
529         size = write_object(f, e, *offset);
530         if (!size) {
531                 e->idx.offset = recursing;
532                 return WRITE_ONE_BREAK;
533         }
534         written_list[nr_written++] = &e->idx;
535
536         /* make sure off_t is sufficiently large not to wrap */
537         if (signed_add_overflows(*offset, size))
538                 die("pack too large for current definition of off_t");
539         *offset += size;
540         return WRITE_ONE_WRITTEN;
541 }
542
543 static int mark_tagged(const char *path, const unsigned char *sha1, int flag,
544                        void *cb_data)
545 {
546         unsigned char peeled[20];
547         struct object_entry *entry = packlist_find(&to_pack, sha1, NULL);
548
549         if (entry)
550                 entry->tagged = 1;
551         if (!peel_ref(path, peeled)) {
552                 entry = packlist_find(&to_pack, peeled, NULL);
553                 if (entry)
554                         entry->tagged = 1;
555         }
556         return 0;
557 }
558
559 static inline void add_to_write_order(struct object_entry **wo,
560                                unsigned int *endp,
561                                struct object_entry *e)
562 {
563         if (e->filled)
564                 return;
565         wo[(*endp)++] = e;
566         e->filled = 1;
567 }
568
569 static void add_descendants_to_write_order(struct object_entry **wo,
570                                            unsigned int *endp,
571                                            struct object_entry *e)
572 {
573         int add_to_order = 1;
574         while (e) {
575                 if (add_to_order) {
576                         struct object_entry *s;
577                         /* add this node... */
578                         add_to_write_order(wo, endp, e);
579                         /* all its siblings... */
580                         for (s = e->delta_sibling; s; s = s->delta_sibling) {
581                                 add_to_write_order(wo, endp, s);
582                         }
583                 }
584                 /* drop down a level to add left subtree nodes if possible */
585                 if (e->delta_child) {
586                         add_to_order = 1;
587                         e = e->delta_child;
588                 } else {
589                         add_to_order = 0;
590                         /* our sibling might have some children, it is next */
591                         if (e->delta_sibling) {
592                                 e = e->delta_sibling;
593                                 continue;
594                         }
595                         /* go back to our parent node */
596                         e = e->delta;
597                         while (e && !e->delta_sibling) {
598                                 /* we're on the right side of a subtree, keep
599                                  * going up until we can go right again */
600                                 e = e->delta;
601                         }
602                         if (!e) {
603                                 /* done- we hit our original root node */
604                                 return;
605                         }
606                         /* pass it off to sibling at this level */
607                         e = e->delta_sibling;
608                 }
609         };
610 }
611
612 static void add_family_to_write_order(struct object_entry **wo,
613                                       unsigned int *endp,
614                                       struct object_entry *e)
615 {
616         struct object_entry *root;
617
618         for (root = e; root->delta; root = root->delta)
619                 ; /* nothing */
620         add_descendants_to_write_order(wo, endp, root);
621 }
622
623 static struct object_entry **compute_write_order(void)
624 {
625         unsigned int i, wo_end, last_untagged;
626
627         struct object_entry **wo = xmalloc(to_pack.nr_objects * sizeof(*wo));
628         struct object_entry *objects = to_pack.objects;
629
630         for (i = 0; i < to_pack.nr_objects; i++) {
631                 objects[i].tagged = 0;
632                 objects[i].filled = 0;
633                 objects[i].delta_child = NULL;
634                 objects[i].delta_sibling = NULL;
635         }
636
637         /*
638          * Fully connect delta_child/delta_sibling network.
639          * Make sure delta_sibling is sorted in the original
640          * recency order.
641          */
642         for (i = to_pack.nr_objects; i > 0;) {
643                 struct object_entry *e = &objects[--i];
644                 if (!e->delta)
645                         continue;
646                 /* Mark me as the first child */
647                 e->delta_sibling = e->delta->delta_child;
648                 e->delta->delta_child = e;
649         }
650
651         /*
652          * Mark objects that are at the tip of tags.
653          */
654         for_each_tag_ref(mark_tagged, NULL);
655
656         /*
657          * Give the objects in the original recency order until
658          * we see a tagged tip.
659          */
660         for (i = wo_end = 0; i < to_pack.nr_objects; i++) {
661                 if (objects[i].tagged)
662                         break;
663                 add_to_write_order(wo, &wo_end, &objects[i]);
664         }
665         last_untagged = i;
666
667         /*
668          * Then fill all the tagged tips.
669          */
670         for (; i < to_pack.nr_objects; i++) {
671                 if (objects[i].tagged)
672                         add_to_write_order(wo, &wo_end, &objects[i]);
673         }
674
675         /*
676          * And then all remaining commits and tags.
677          */
678         for (i = last_untagged; i < to_pack.nr_objects; i++) {
679                 if (objects[i].type != OBJ_COMMIT &&
680                     objects[i].type != OBJ_TAG)
681                         continue;
682                 add_to_write_order(wo, &wo_end, &objects[i]);
683         }
684
685         /*
686          * And then all the trees.
687          */
688         for (i = last_untagged; i < to_pack.nr_objects; i++) {
689                 if (objects[i].type != OBJ_TREE)
690                         continue;
691                 add_to_write_order(wo, &wo_end, &objects[i]);
692         }
693
694         /*
695          * Finally all the rest in really tight order
696          */
697         for (i = last_untagged; i < to_pack.nr_objects; i++) {
698                 if (!objects[i].filled)
699                         add_family_to_write_order(wo, &wo_end, &objects[i]);
700         }
701
702         if (wo_end != to_pack.nr_objects)
703                 die("ordered %u objects, expected %"PRIu32, wo_end, to_pack.nr_objects);
704
705         return wo;
706 }
707
708 static off_t write_reused_pack(struct sha1file *f)
709 {
710         unsigned char buffer[8192];
711         off_t to_write, total;
712         int fd;
713
714         if (!is_pack_valid(reuse_packfile))
715                 die("packfile is invalid: %s", reuse_packfile->pack_name);
716
717         fd = git_open_noatime(reuse_packfile->pack_name);
718         if (fd < 0)
719                 die_errno("unable to open packfile for reuse: %s",
720                           reuse_packfile->pack_name);
721
722         if (lseek(fd, sizeof(struct pack_header), SEEK_SET) == -1)
723                 die_errno("unable to seek in reused packfile");
724
725         if (reuse_packfile_offset < 0)
726                 reuse_packfile_offset = reuse_packfile->pack_size - 20;
727
728         total = to_write = reuse_packfile_offset - sizeof(struct pack_header);
729
730         while (to_write) {
731                 int read_pack = xread(fd, buffer, sizeof(buffer));
732
733                 if (read_pack <= 0)
734                         die_errno("unable to read from reused packfile");
735
736                 if (read_pack > to_write)
737                         read_pack = to_write;
738
739                 sha1write(f, buffer, read_pack);
740                 to_write -= read_pack;
741
742                 /*
743                  * We don't know the actual number of objects written,
744                  * only how many bytes written, how many bytes total, and
745                  * how many objects total. So we can fake it by pretending all
746                  * objects we are writing are the same size. This gives us a
747                  * smooth progress meter, and at the end it matches the true
748                  * answer.
749                  */
750                 written = reuse_packfile_objects *
751                                 (((double)(total - to_write)) / total);
752                 display_progress(progress_state, written);
753         }
754
755         close(fd);
756         written = reuse_packfile_objects;
757         display_progress(progress_state, written);
758         return reuse_packfile_offset - sizeof(struct pack_header);
759 }
760
761 static void write_pack_file(void)
762 {
763         uint32_t i = 0, j;
764         struct sha1file *f;
765         off_t offset;
766         uint32_t nr_remaining = nr_result;
767         time_t last_mtime = 0;
768         struct object_entry **write_order;
769
770         if (progress > pack_to_stdout)
771                 progress_state = start_progress(_("Writing objects"), nr_result);
772         written_list = xmalloc(to_pack.nr_objects * sizeof(*written_list));
773         write_order = compute_write_order();
774
775         do {
776                 unsigned char sha1[20];
777                 char *pack_tmp_name = NULL;
778
779                 if (pack_to_stdout)
780                         f = sha1fd_throughput(1, "<stdout>", progress_state);
781                 else
782                         f = create_tmp_packfile(&pack_tmp_name);
783
784                 offset = write_pack_header(f, nr_remaining);
785
786                 if (reuse_packfile) {
787                         off_t packfile_size;
788                         assert(pack_to_stdout);
789
790                         packfile_size = write_reused_pack(f);
791                         offset += packfile_size;
792                 }
793
794                 nr_written = 0;
795                 for (; i < to_pack.nr_objects; i++) {
796                         struct object_entry *e = write_order[i];
797                         if (write_one(f, e, &offset) == WRITE_ONE_BREAK)
798                                 break;
799                         display_progress(progress_state, written);
800                 }
801
802                 /*
803                  * Did we write the wrong # entries in the header?
804                  * If so, rewrite it like in fast-import
805                  */
806                 if (pack_to_stdout) {
807                         sha1close(f, sha1, CSUM_CLOSE);
808                 } else if (nr_written == nr_remaining) {
809                         sha1close(f, sha1, CSUM_FSYNC);
810                 } else {
811                         int fd = sha1close(f, sha1, 0);
812                         fixup_pack_header_footer(fd, sha1, pack_tmp_name,
813                                                  nr_written, sha1, offset);
814                         close(fd);
815                         write_bitmap_index = 0;
816                 }
817
818                 if (!pack_to_stdout) {
819                         struct stat st;
820                         struct strbuf tmpname = STRBUF_INIT;
821
822                         /*
823                          * Packs are runtime accessed in their mtime
824                          * order since newer packs are more likely to contain
825                          * younger objects.  So if we are creating multiple
826                          * packs then we should modify the mtime of later ones
827                          * to preserve this property.
828                          */
829                         if (stat(pack_tmp_name, &st) < 0) {
830                                 warning("failed to stat %s: %s",
831                                         pack_tmp_name, strerror(errno));
832                         } else if (!last_mtime) {
833                                 last_mtime = st.st_mtime;
834                         } else {
835                                 struct utimbuf utb;
836                                 utb.actime = st.st_atime;
837                                 utb.modtime = --last_mtime;
838                                 if (utime(pack_tmp_name, &utb) < 0)
839                                         warning("failed utime() on %s: %s",
840                                                 pack_tmp_name, strerror(errno));
841                         }
842
843                         strbuf_addf(&tmpname, "%s-", base_name);
844
845                         if (write_bitmap_index) {
846                                 bitmap_writer_set_checksum(sha1);
847                                 bitmap_writer_build_type_index(written_list, nr_written);
848                         }
849
850                         finish_tmp_packfile(&tmpname, pack_tmp_name,
851                                             written_list, nr_written,
852                                             &pack_idx_opts, sha1);
853
854                         if (write_bitmap_index) {
855                                 strbuf_addf(&tmpname, "%s.bitmap", sha1_to_hex(sha1));
856
857                                 stop_progress(&progress_state);
858
859                                 bitmap_writer_show_progress(progress);
860                                 bitmap_writer_reuse_bitmaps(&to_pack);
861                                 bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
862                                 bitmap_writer_build(&to_pack);
863                                 bitmap_writer_finish(written_list, nr_written,
864                                                      tmpname.buf, write_bitmap_options);
865                                 write_bitmap_index = 0;
866                         }
867
868                         strbuf_release(&tmpname);
869                         free(pack_tmp_name);
870                         puts(sha1_to_hex(sha1));
871                 }
872
873                 /* mark written objects as written to previous pack */
874                 for (j = 0; j < nr_written; j++) {
875                         written_list[j]->offset = (off_t)-1;
876                 }
877                 nr_remaining -= nr_written;
878         } while (nr_remaining && i < to_pack.nr_objects);
879
880         free(written_list);
881         free(write_order);
882         stop_progress(&progress_state);
883         if (written != nr_result)
884                 die("wrote %"PRIu32" objects while expecting %"PRIu32,
885                         written, nr_result);
886 }
887
888 static void setup_delta_attr_check(struct git_attr_check *check)
889 {
890         static struct git_attr *attr_delta;
891
892         if (!attr_delta)
893                 attr_delta = git_attr("delta");
894
895         check[0].attr = attr_delta;
896 }
897
898 static int no_try_delta(const char *path)
899 {
900         struct git_attr_check check[1];
901
902         setup_delta_attr_check(check);
903         if (git_check_attr(path, ARRAY_SIZE(check), check))
904                 return 0;
905         if (ATTR_FALSE(check->value))
906                 return 1;
907         return 0;
908 }
909
910 /*
911  * When adding an object, check whether we have already added it
912  * to our packing list. If so, we can skip. However, if we are
913  * being asked to excludei t, but the previous mention was to include
914  * it, make sure to adjust its flags and tweak our numbers accordingly.
915  *
916  * As an optimization, we pass out the index position where we would have
917  * found the item, since that saves us from having to look it up again a
918  * few lines later when we want to add the new entry.
919  */
920 static int have_duplicate_entry(const unsigned char *sha1,
921                                 int exclude,
922                                 uint32_t *index_pos)
923 {
924         struct object_entry *entry;
925
926         entry = packlist_find(&to_pack, sha1, index_pos);
927         if (!entry)
928                 return 0;
929
930         if (exclude) {
931                 if (!entry->preferred_base)
932                         nr_result--;
933                 entry->preferred_base = 1;
934         }
935
936         return 1;
937 }
938
939 /*
940  * Check whether we want the object in the pack (e.g., we do not want
941  * objects found in non-local stores if the "--local" option was used).
942  *
943  * As a side effect of this check, we will find the packed version of this
944  * object, if any. We therefore pass out the pack information to avoid having
945  * to look it up again later.
946  */
947 static int want_object_in_pack(const unsigned char *sha1,
948                                int exclude,
949                                struct packed_git **found_pack,
950                                off_t *found_offset)
951 {
952         struct packed_git *p;
953
954         if (!exclude && local && has_loose_object_nonlocal(sha1))
955                 return 0;
956
957         *found_pack = NULL;
958         *found_offset = 0;
959
960         for (p = packed_git; p; p = p->next) {
961                 off_t offset = find_pack_entry_one(sha1, p);
962                 if (offset) {
963                         if (!*found_pack) {
964                                 if (!is_pack_valid(p)) {
965                                         warning("packfile %s cannot be accessed", p->pack_name);
966                                         continue;
967                                 }
968                                 *found_offset = offset;
969                                 *found_pack = p;
970                         }
971                         if (exclude)
972                                 return 1;
973                         if (incremental)
974                                 return 0;
975                         if (local && !p->pack_local)
976                                 return 0;
977                         if (ignore_packed_keep && p->pack_local && p->pack_keep)
978                                 return 0;
979                 }
980         }
981
982         return 1;
983 }
984
985 static void create_object_entry(const unsigned char *sha1,
986                                 enum object_type type,
987                                 uint32_t hash,
988                                 int exclude,
989                                 int no_try_delta,
990                                 uint32_t index_pos,
991                                 struct packed_git *found_pack,
992                                 off_t found_offset)
993 {
994         struct object_entry *entry;
995
996         entry = packlist_alloc(&to_pack, sha1, index_pos);
997         entry->hash = hash;
998         if (type)
999                 entry->type = type;
1000         if (exclude)
1001                 entry->preferred_base = 1;
1002         else
1003                 nr_result++;
1004         if (found_pack) {
1005                 entry->in_pack = found_pack;
1006                 entry->in_pack_offset = found_offset;
1007         }
1008
1009         entry->no_try_delta = no_try_delta;
1010 }
1011
1012 static const char no_closure_warning[] = N_(
1013 "disabling bitmap writing, as some objects are not being packed"
1014 );
1015
1016 static int add_object_entry(const unsigned char *sha1, enum object_type type,
1017                             const char *name, int exclude)
1018 {
1019         struct packed_git *found_pack;
1020         off_t found_offset;
1021         uint32_t index_pos;
1022
1023         if (have_duplicate_entry(sha1, exclude, &index_pos))
1024                 return 0;
1025
1026         if (!want_object_in_pack(sha1, exclude, &found_pack, &found_offset)) {
1027                 /* The pack is missing an object, so it will not have closure */
1028                 if (write_bitmap_index) {
1029                         warning(_(no_closure_warning));
1030                         write_bitmap_index = 0;
1031                 }
1032                 return 0;
1033         }
1034
1035         create_object_entry(sha1, type, pack_name_hash(name),
1036                             exclude, name && no_try_delta(name),
1037                             index_pos, found_pack, found_offset);
1038
1039         display_progress(progress_state, nr_result);
1040         return 1;
1041 }
1042
1043 static int add_object_entry_from_bitmap(const unsigned char *sha1,
1044                                         enum object_type type,
1045                                         int flags, uint32_t name_hash,
1046                                         struct packed_git *pack, off_t offset)
1047 {
1048         uint32_t index_pos;
1049
1050         if (have_duplicate_entry(sha1, 0, &index_pos))
1051                 return 0;
1052
1053         create_object_entry(sha1, type, name_hash, 0, 0, index_pos, pack, offset);
1054
1055         display_progress(progress_state, nr_result);
1056         return 1;
1057 }
1058
1059 struct pbase_tree_cache {
1060         unsigned char sha1[20];
1061         int ref;
1062         int temporary;
1063         void *tree_data;
1064         unsigned long tree_size;
1065 };
1066
1067 static struct pbase_tree_cache *(pbase_tree_cache[256]);
1068 static int pbase_tree_cache_ix(const unsigned char *sha1)
1069 {
1070         return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
1071 }
1072 static int pbase_tree_cache_ix_incr(int ix)
1073 {
1074         return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
1075 }
1076
1077 static struct pbase_tree {
1078         struct pbase_tree *next;
1079         /* This is a phony "cache" entry; we are not
1080          * going to evict it or find it through _get()
1081          * mechanism -- this is for the toplevel node that
1082          * would almost always change with any commit.
1083          */
1084         struct pbase_tree_cache pcache;
1085 } *pbase_tree;
1086
1087 static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
1088 {
1089         struct pbase_tree_cache *ent, *nent;
1090         void *data;
1091         unsigned long size;
1092         enum object_type type;
1093         int neigh;
1094         int my_ix = pbase_tree_cache_ix(sha1);
1095         int available_ix = -1;
1096
1097         /* pbase-tree-cache acts as a limited hashtable.
1098          * your object will be found at your index or within a few
1099          * slots after that slot if it is cached.
1100          */
1101         for (neigh = 0; neigh < 8; neigh++) {
1102                 ent = pbase_tree_cache[my_ix];
1103                 if (ent && !hashcmp(ent->sha1, sha1)) {
1104                         ent->ref++;
1105                         return ent;
1106                 }
1107                 else if (((available_ix < 0) && (!ent || !ent->ref)) ||
1108                          ((0 <= available_ix) &&
1109                           (!ent && pbase_tree_cache[available_ix])))
1110                         available_ix = my_ix;
1111                 if (!ent)
1112                         break;
1113                 my_ix = pbase_tree_cache_ix_incr(my_ix);
1114         }
1115
1116         /* Did not find one.  Either we got a bogus request or
1117          * we need to read and perhaps cache.
1118          */
1119         data = read_sha1_file(sha1, &type, &size);
1120         if (!data)
1121                 return NULL;
1122         if (type != OBJ_TREE) {
1123                 free(data);
1124                 return NULL;
1125         }
1126
1127         /* We need to either cache or return a throwaway copy */
1128
1129         if (available_ix < 0)
1130                 ent = NULL;
1131         else {
1132                 ent = pbase_tree_cache[available_ix];
1133                 my_ix = available_ix;
1134         }
1135
1136         if (!ent) {
1137                 nent = xmalloc(sizeof(*nent));
1138                 nent->temporary = (available_ix < 0);
1139         }
1140         else {
1141                 /* evict and reuse */
1142                 free(ent->tree_data);
1143                 nent = ent;
1144         }
1145         hashcpy(nent->sha1, sha1);
1146         nent->tree_data = data;
1147         nent->tree_size = size;
1148         nent->ref = 1;
1149         if (!nent->temporary)
1150                 pbase_tree_cache[my_ix] = nent;
1151         return nent;
1152 }
1153
1154 static void pbase_tree_put(struct pbase_tree_cache *cache)
1155 {
1156         if (!cache->temporary) {
1157                 cache->ref--;
1158                 return;
1159         }
1160         free(cache->tree_data);
1161         free(cache);
1162 }
1163
1164 static int name_cmp_len(const char *name)
1165 {
1166         int i;
1167         for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
1168                 ;
1169         return i;
1170 }
1171
1172 static void add_pbase_object(struct tree_desc *tree,
1173                              const char *name,
1174                              int cmplen,
1175                              const char *fullname)
1176 {
1177         struct name_entry entry;
1178         int cmp;
1179
1180         while (tree_entry(tree,&entry)) {
1181                 if (S_ISGITLINK(entry.mode))
1182                         continue;
1183                 cmp = tree_entry_len(&entry) != cmplen ? 1 :
1184                       memcmp(name, entry.path, cmplen);
1185                 if (cmp > 0)
1186                         continue;
1187                 if (cmp < 0)
1188                         return;
1189                 if (name[cmplen] != '/') {
1190                         add_object_entry(entry.sha1,
1191                                          object_type(entry.mode),
1192                                          fullname, 1);
1193                         return;
1194                 }
1195                 if (S_ISDIR(entry.mode)) {
1196                         struct tree_desc sub;
1197                         struct pbase_tree_cache *tree;
1198                         const char *down = name+cmplen+1;
1199                         int downlen = name_cmp_len(down);
1200
1201                         tree = pbase_tree_get(entry.sha1);
1202                         if (!tree)
1203                                 return;
1204                         init_tree_desc(&sub, tree->tree_data, tree->tree_size);
1205
1206                         add_pbase_object(&sub, down, downlen, fullname);
1207                         pbase_tree_put(tree);
1208                 }
1209         }
1210 }
1211
1212 static unsigned *done_pbase_paths;
1213 static int done_pbase_paths_num;
1214 static int done_pbase_paths_alloc;
1215 static int done_pbase_path_pos(unsigned hash)
1216 {
1217         int lo = 0;
1218         int hi = done_pbase_paths_num;
1219         while (lo < hi) {
1220                 int mi = (hi + lo) / 2;
1221                 if (done_pbase_paths[mi] == hash)
1222                         return mi;
1223                 if (done_pbase_paths[mi] < hash)
1224                         hi = mi;
1225                 else
1226                         lo = mi + 1;
1227         }
1228         return -lo-1;
1229 }
1230
1231 static int check_pbase_path(unsigned hash)
1232 {
1233         int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
1234         if (0 <= pos)
1235                 return 1;
1236         pos = -pos - 1;
1237         ALLOC_GROW(done_pbase_paths,
1238                    done_pbase_paths_num + 1,
1239                    done_pbase_paths_alloc);
1240         done_pbase_paths_num++;
1241         if (pos < done_pbase_paths_num)
1242                 memmove(done_pbase_paths + pos + 1,
1243                         done_pbase_paths + pos,
1244                         (done_pbase_paths_num - pos - 1) * sizeof(unsigned));
1245         done_pbase_paths[pos] = hash;
1246         return 0;
1247 }
1248
1249 static void add_preferred_base_object(const char *name)
1250 {
1251         struct pbase_tree *it;
1252         int cmplen;
1253         unsigned hash = pack_name_hash(name);
1254
1255         if (!num_preferred_base || check_pbase_path(hash))
1256                 return;
1257
1258         cmplen = name_cmp_len(name);
1259         for (it = pbase_tree; it; it = it->next) {
1260                 if (cmplen == 0) {
1261                         add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
1262                 }
1263                 else {
1264                         struct tree_desc tree;
1265                         init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
1266                         add_pbase_object(&tree, name, cmplen, name);
1267                 }
1268         }
1269 }
1270
1271 static void add_preferred_base(unsigned char *sha1)
1272 {
1273         struct pbase_tree *it;
1274         void *data;
1275         unsigned long size;
1276         unsigned char tree_sha1[20];
1277
1278         if (window <= num_preferred_base++)
1279                 return;
1280
1281         data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
1282         if (!data)
1283                 return;
1284
1285         for (it = pbase_tree; it; it = it->next) {
1286                 if (!hashcmp(it->pcache.sha1, tree_sha1)) {
1287                         free(data);
1288                         return;
1289                 }
1290         }
1291
1292         it = xcalloc(1, sizeof(*it));
1293         it->next = pbase_tree;
1294         pbase_tree = it;
1295
1296         hashcpy(it->pcache.sha1, tree_sha1);
1297         it->pcache.tree_data = data;
1298         it->pcache.tree_size = size;
1299 }
1300
1301 static void cleanup_preferred_base(void)
1302 {
1303         struct pbase_tree *it;
1304         unsigned i;
1305
1306         it = pbase_tree;
1307         pbase_tree = NULL;
1308         while (it) {
1309                 struct pbase_tree *this = it;
1310                 it = this->next;
1311                 free(this->pcache.tree_data);
1312                 free(this);
1313         }
1314
1315         for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
1316                 if (!pbase_tree_cache[i])
1317                         continue;
1318                 free(pbase_tree_cache[i]->tree_data);
1319                 free(pbase_tree_cache[i]);
1320                 pbase_tree_cache[i] = NULL;
1321         }
1322
1323         free(done_pbase_paths);
1324         done_pbase_paths = NULL;
1325         done_pbase_paths_num = done_pbase_paths_alloc = 0;
1326 }
1327
1328 static void check_object(struct object_entry *entry)
1329 {
1330         if (entry->in_pack) {
1331                 struct packed_git *p = entry->in_pack;
1332                 struct pack_window *w_curs = NULL;
1333                 const unsigned char *base_ref = NULL;
1334                 struct object_entry *base_entry;
1335                 unsigned long used, used_0;
1336                 unsigned long avail;
1337                 off_t ofs;
1338                 unsigned char *buf, c;
1339
1340                 buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
1341
1342                 /*
1343                  * We want in_pack_type even if we do not reuse delta
1344                  * since non-delta representations could still be reused.
1345                  */
1346                 used = unpack_object_header_buffer(buf, avail,
1347                                                    &entry->in_pack_type,
1348                                                    &entry->size);
1349                 if (used == 0)
1350                         goto give_up;
1351
1352                 /*
1353                  * Determine if this is a delta and if so whether we can
1354                  * reuse it or not.  Otherwise let's find out as cheaply as
1355                  * possible what the actual type and size for this object is.
1356                  */
1357                 switch (entry->in_pack_type) {
1358                 default:
1359                         /* Not a delta hence we've already got all we need. */
1360                         entry->type = entry->in_pack_type;
1361                         entry->in_pack_header_size = used;
1362                         if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
1363                                 goto give_up;
1364                         unuse_pack(&w_curs);
1365                         return;
1366                 case OBJ_REF_DELTA:
1367                         if (reuse_delta && !entry->preferred_base)
1368                                 base_ref = use_pack(p, &w_curs,
1369                                                 entry->in_pack_offset + used, NULL);
1370                         entry->in_pack_header_size = used + 20;
1371                         break;
1372                 case OBJ_OFS_DELTA:
1373                         buf = use_pack(p, &w_curs,
1374                                        entry->in_pack_offset + used, NULL);
1375                         used_0 = 0;
1376                         c = buf[used_0++];
1377                         ofs = c & 127;
1378                         while (c & 128) {
1379                                 ofs += 1;
1380                                 if (!ofs || MSB(ofs, 7)) {
1381                                         error("delta base offset overflow in pack for %s",
1382                                               sha1_to_hex(entry->idx.sha1));
1383                                         goto give_up;
1384                                 }
1385                                 c = buf[used_0++];
1386                                 ofs = (ofs << 7) + (c & 127);
1387                         }
1388                         ofs = entry->in_pack_offset - ofs;
1389                         if (ofs <= 0 || ofs >= entry->in_pack_offset) {
1390                                 error("delta base offset out of bound for %s",
1391                                       sha1_to_hex(entry->idx.sha1));
1392                                 goto give_up;
1393                         }
1394                         if (reuse_delta && !entry->preferred_base) {
1395                                 struct revindex_entry *revidx;
1396                                 revidx = find_pack_revindex(p, ofs);
1397                                 if (!revidx)
1398                                         goto give_up;
1399                                 base_ref = nth_packed_object_sha1(p, revidx->nr);
1400                         }
1401                         entry->in_pack_header_size = used + used_0;
1402                         break;
1403                 }
1404
1405                 if (base_ref && (base_entry = packlist_find(&to_pack, base_ref, NULL))) {
1406                         /*
1407                          * If base_ref was set above that means we wish to
1408                          * reuse delta data, and we even found that base
1409                          * in the list of objects we want to pack. Goodie!
1410                          *
1411                          * Depth value does not matter - find_deltas() will
1412                          * never consider reused delta as the base object to
1413                          * deltify other objects against, in order to avoid
1414                          * circular deltas.
1415                          */
1416                         entry->type = entry->in_pack_type;
1417                         entry->delta = base_entry;
1418                         entry->delta_size = entry->size;
1419                         entry->delta_sibling = base_entry->delta_child;
1420                         base_entry->delta_child = entry;
1421                         unuse_pack(&w_curs);
1422                         return;
1423                 }
1424
1425                 if (entry->type) {
1426                         /*
1427                          * This must be a delta and we already know what the
1428                          * final object type is.  Let's extract the actual
1429                          * object size from the delta header.
1430                          */
1431                         entry->size = get_size_from_delta(p, &w_curs,
1432                                         entry->in_pack_offset + entry->in_pack_header_size);
1433                         if (entry->size == 0)
1434                                 goto give_up;
1435                         unuse_pack(&w_curs);
1436                         return;
1437                 }
1438
1439                 /*
1440                  * No choice but to fall back to the recursive delta walk
1441                  * with sha1_object_info() to find about the object type
1442                  * at this point...
1443                  */
1444                 give_up:
1445                 unuse_pack(&w_curs);
1446         }
1447
1448         entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
1449         /*
1450          * The error condition is checked in prepare_pack().  This is
1451          * to permit a missing preferred base object to be ignored
1452          * as a preferred base.  Doing so can result in a larger
1453          * pack file, but the transfer will still take place.
1454          */
1455 }
1456
1457 static int pack_offset_sort(const void *_a, const void *_b)
1458 {
1459         const struct object_entry *a = *(struct object_entry **)_a;
1460         const struct object_entry *b = *(struct object_entry **)_b;
1461
1462         /* avoid filesystem trashing with loose objects */
1463         if (!a->in_pack && !b->in_pack)
1464                 return hashcmp(a->idx.sha1, b->idx.sha1);
1465
1466         if (a->in_pack < b->in_pack)
1467                 return -1;
1468         if (a->in_pack > b->in_pack)
1469                 return 1;
1470         return a->in_pack_offset < b->in_pack_offset ? -1 :
1471                         (a->in_pack_offset > b->in_pack_offset);
1472 }
1473
1474 static void get_object_details(void)
1475 {
1476         uint32_t i;
1477         struct object_entry **sorted_by_offset;
1478
1479         sorted_by_offset = xcalloc(to_pack.nr_objects, sizeof(struct object_entry *));
1480         for (i = 0; i < to_pack.nr_objects; i++)
1481                 sorted_by_offset[i] = to_pack.objects + i;
1482         qsort(sorted_by_offset, to_pack.nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
1483
1484         for (i = 0; i < to_pack.nr_objects; i++) {
1485                 struct object_entry *entry = sorted_by_offset[i];
1486                 check_object(entry);
1487                 if (big_file_threshold < entry->size)
1488                         entry->no_try_delta = 1;
1489         }
1490
1491         free(sorted_by_offset);
1492 }
1493
1494 /*
1495  * We search for deltas in a list sorted by type, by filename hash, and then
1496  * by size, so that we see progressively smaller and smaller files.
1497  * That's because we prefer deltas to be from the bigger file
1498  * to the smaller -- deletes are potentially cheaper, but perhaps
1499  * more importantly, the bigger file is likely the more recent
1500  * one.  The deepest deltas are therefore the oldest objects which are
1501  * less susceptible to be accessed often.
1502  */
1503 static int type_size_sort(const void *_a, const void *_b)
1504 {
1505         const struct object_entry *a = *(struct object_entry **)_a;
1506         const struct object_entry *b = *(struct object_entry **)_b;
1507
1508         if (a->type > b->type)
1509                 return -1;
1510         if (a->type < b->type)
1511                 return 1;
1512         if (a->hash > b->hash)
1513                 return -1;
1514         if (a->hash < b->hash)
1515                 return 1;
1516         if (a->preferred_base > b->preferred_base)
1517                 return -1;
1518         if (a->preferred_base < b->preferred_base)
1519                 return 1;
1520         if (a->size > b->size)
1521                 return -1;
1522         if (a->size < b->size)
1523                 return 1;
1524         return a < b ? -1 : (a > b);  /* newest first */
1525 }
1526
1527 struct unpacked {
1528         struct object_entry *entry;
1529         void *data;
1530         struct delta_index *index;
1531         unsigned depth;
1532 };
1533
1534 static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
1535                            unsigned long delta_size)
1536 {
1537         if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
1538                 return 0;
1539
1540         if (delta_size < cache_max_small_delta_size)
1541                 return 1;
1542
1543         /* cache delta, if objects are large enough compared to delta size */
1544         if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
1545                 return 1;
1546
1547         return 0;
1548 }
1549
1550 #ifndef NO_PTHREADS
1551
1552 static pthread_mutex_t read_mutex;
1553 #define read_lock()             pthread_mutex_lock(&read_mutex)
1554 #define read_unlock()           pthread_mutex_unlock(&read_mutex)
1555
1556 static pthread_mutex_t cache_mutex;
1557 #define cache_lock()            pthread_mutex_lock(&cache_mutex)
1558 #define cache_unlock()          pthread_mutex_unlock(&cache_mutex)
1559
1560 static pthread_mutex_t progress_mutex;
1561 #define progress_lock()         pthread_mutex_lock(&progress_mutex)
1562 #define progress_unlock()       pthread_mutex_unlock(&progress_mutex)
1563
1564 #else
1565
1566 #define read_lock()             (void)0
1567 #define read_unlock()           (void)0
1568 #define cache_lock()            (void)0
1569 #define cache_unlock()          (void)0
1570 #define progress_lock()         (void)0
1571 #define progress_unlock()       (void)0
1572
1573 #endif
1574
1575 static int try_delta(struct unpacked *trg, struct unpacked *src,
1576                      unsigned max_depth, unsigned long *mem_usage)
1577 {
1578         struct object_entry *trg_entry = trg->entry;
1579         struct object_entry *src_entry = src->entry;
1580         unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
1581         unsigned ref_depth;
1582         enum object_type type;
1583         void *delta_buf;
1584
1585         /* Don't bother doing diffs between different types */
1586         if (trg_entry->type != src_entry->type)
1587                 return -1;
1588
1589         /*
1590          * We do not bother to try a delta that we discarded on an
1591          * earlier try, but only when reusing delta data.  Note that
1592          * src_entry that is marked as the preferred_base should always
1593          * be considered, as even if we produce a suboptimal delta against
1594          * it, we will still save the transfer cost, as we already know
1595          * the other side has it and we won't send src_entry at all.
1596          */
1597         if (reuse_delta && trg_entry->in_pack &&
1598             trg_entry->in_pack == src_entry->in_pack &&
1599             !src_entry->preferred_base &&
1600             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1601             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1602                 return 0;
1603
1604         /* Let's not bust the allowed depth. */
1605         if (src->depth >= max_depth)
1606                 return 0;
1607
1608         /* Now some size filtering heuristics. */
1609         trg_size = trg_entry->size;
1610         if (!trg_entry->delta) {
1611                 max_size = trg_size/2 - 20;
1612                 ref_depth = 1;
1613         } else {
1614                 max_size = trg_entry->delta_size;
1615                 ref_depth = trg->depth;
1616         }
1617         max_size = (uint64_t)max_size * (max_depth - src->depth) /
1618                                                 (max_depth - ref_depth + 1);
1619         if (max_size == 0)
1620                 return 0;
1621         src_size = src_entry->size;
1622         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1623         if (sizediff >= max_size)
1624                 return 0;
1625         if (trg_size < src_size / 32)
1626                 return 0;
1627
1628         /* Load data if not already done */
1629         if (!trg->data) {
1630                 read_lock();
1631                 trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
1632                 read_unlock();
1633                 if (!trg->data)
1634                         die("object %s cannot be read",
1635                             sha1_to_hex(trg_entry->idx.sha1));
1636                 if (sz != trg_size)
1637                         die("object %s inconsistent object length (%lu vs %lu)",
1638                             sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
1639                 *mem_usage += sz;
1640         }
1641         if (!src->data) {
1642                 read_lock();
1643                 src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
1644                 read_unlock();
1645                 if (!src->data) {
1646                         if (src_entry->preferred_base) {
1647                                 static int warned = 0;
1648                                 if (!warned++)
1649                                         warning("object %s cannot be read",
1650                                                 sha1_to_hex(src_entry->idx.sha1));
1651                                 /*
1652                                  * Those objects are not included in the
1653                                  * resulting pack.  Be resilient and ignore
1654                                  * them if they can't be read, in case the
1655                                  * pack could be created nevertheless.
1656                                  */
1657                                 return 0;
1658                         }
1659                         die("object %s cannot be read",
1660                             sha1_to_hex(src_entry->idx.sha1));
1661                 }
1662                 if (sz != src_size)
1663                         die("object %s inconsistent object length (%lu vs %lu)",
1664                             sha1_to_hex(src_entry->idx.sha1), sz, src_size);
1665                 *mem_usage += sz;
1666         }
1667         if (!src->index) {
1668                 src->index = create_delta_index(src->data, src_size);
1669                 if (!src->index) {
1670                         static int warned = 0;
1671                         if (!warned++)
1672                                 warning("suboptimal pack - out of memory");
1673                         return 0;
1674                 }
1675                 *mem_usage += sizeof_delta_index(src->index);
1676         }
1677
1678         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1679         if (!delta_buf)
1680                 return 0;
1681
1682         if (trg_entry->delta) {
1683                 /* Prefer only shallower same-sized deltas. */
1684                 if (delta_size == trg_entry->delta_size &&
1685                     src->depth + 1 >= trg->depth) {
1686                         free(delta_buf);
1687                         return 0;
1688                 }
1689         }
1690
1691         /*
1692          * Handle memory allocation outside of the cache
1693          * accounting lock.  Compiler will optimize the strangeness
1694          * away when NO_PTHREADS is defined.
1695          */
1696         free(trg_entry->delta_data);
1697         cache_lock();
1698         if (trg_entry->delta_data) {
1699                 delta_cache_size -= trg_entry->delta_size;
1700                 trg_entry->delta_data = NULL;
1701         }
1702         if (delta_cacheable(src_size, trg_size, delta_size)) {
1703                 delta_cache_size += delta_size;
1704                 cache_unlock();
1705                 trg_entry->delta_data = xrealloc(delta_buf, delta_size);
1706         } else {
1707                 cache_unlock();
1708                 free(delta_buf);
1709         }
1710
1711         trg_entry->delta = src_entry;
1712         trg_entry->delta_size = delta_size;
1713         trg->depth = src->depth + 1;
1714
1715         return 1;
1716 }
1717
1718 static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
1719 {
1720         struct object_entry *child = me->delta_child;
1721         unsigned int m = n;
1722         while (child) {
1723                 unsigned int c = check_delta_limit(child, n + 1);
1724                 if (m < c)
1725                         m = c;
1726                 child = child->delta_sibling;
1727         }
1728         return m;
1729 }
1730
1731 static unsigned long free_unpacked(struct unpacked *n)
1732 {
1733         unsigned long freed_mem = sizeof_delta_index(n->index);
1734         free_delta_index(n->index);
1735         n->index = NULL;
1736         if (n->data) {
1737                 freed_mem += n->entry->size;
1738                 free(n->data);
1739                 n->data = NULL;
1740         }
1741         n->entry = NULL;
1742         n->depth = 0;
1743         return freed_mem;
1744 }
1745
1746 static void find_deltas(struct object_entry **list, unsigned *list_size,
1747                         int window, int depth, unsigned *processed)
1748 {
1749         uint32_t i, idx = 0, count = 0;
1750         struct unpacked *array;
1751         unsigned long mem_usage = 0;
1752
1753         array = xcalloc(window, sizeof(struct unpacked));
1754
1755         for (;;) {
1756                 struct object_entry *entry;
1757                 struct unpacked *n = array + idx;
1758                 int j, max_depth, best_base = -1;
1759
1760                 progress_lock();
1761                 if (!*list_size) {
1762                         progress_unlock();
1763                         break;
1764                 }
1765                 entry = *list++;
1766                 (*list_size)--;
1767                 if (!entry->preferred_base) {
1768                         (*processed)++;
1769                         display_progress(progress_state, *processed);
1770                 }
1771                 progress_unlock();
1772
1773                 mem_usage -= free_unpacked(n);
1774                 n->entry = entry;
1775
1776                 while (window_memory_limit &&
1777                        mem_usage > window_memory_limit &&
1778                        count > 1) {
1779                         uint32_t tail = (idx + window - count) % window;
1780                         mem_usage -= free_unpacked(array + tail);
1781                         count--;
1782                 }
1783
1784                 /* We do not compute delta to *create* objects we are not
1785                  * going to pack.
1786                  */
1787                 if (entry->preferred_base)
1788                         goto next;
1789
1790                 /*
1791                  * If the current object is at pack edge, take the depth the
1792                  * objects that depend on the current object into account
1793                  * otherwise they would become too deep.
1794                  */
1795                 max_depth = depth;
1796                 if (entry->delta_child) {
1797                         max_depth -= check_delta_limit(entry, 0);
1798                         if (max_depth <= 0)
1799                                 goto next;
1800                 }
1801
1802                 j = window;
1803                 while (--j > 0) {
1804                         int ret;
1805                         uint32_t other_idx = idx + j;
1806                         struct unpacked *m;
1807                         if (other_idx >= window)
1808                                 other_idx -= window;
1809                         m = array + other_idx;
1810                         if (!m->entry)
1811                                 break;
1812                         ret = try_delta(n, m, max_depth, &mem_usage);
1813                         if (ret < 0)
1814                                 break;
1815                         else if (ret > 0)
1816                                 best_base = other_idx;
1817                 }
1818
1819                 /*
1820                  * If we decided to cache the delta data, then it is best
1821                  * to compress it right away.  First because we have to do
1822                  * it anyway, and doing it here while we're threaded will
1823                  * save a lot of time in the non threaded write phase,
1824                  * as well as allow for caching more deltas within
1825                  * the same cache size limit.
1826                  * ...
1827                  * But only if not writing to stdout, since in that case
1828                  * the network is most likely throttling writes anyway,
1829                  * and therefore it is best to go to the write phase ASAP
1830                  * instead, as we can afford spending more time compressing
1831                  * between writes at that moment.
1832                  */
1833                 if (entry->delta_data && !pack_to_stdout) {
1834                         entry->z_delta_size = do_compress(&entry->delta_data,
1835                                                           entry->delta_size);
1836                         cache_lock();
1837                         delta_cache_size -= entry->delta_size;
1838                         delta_cache_size += entry->z_delta_size;
1839                         cache_unlock();
1840                 }
1841
1842                 /* if we made n a delta, and if n is already at max
1843                  * depth, leaving it in the window is pointless.  we
1844                  * should evict it first.
1845                  */
1846                 if (entry->delta && max_depth <= n->depth)
1847                         continue;
1848
1849                 /*
1850                  * Move the best delta base up in the window, after the
1851                  * currently deltified object, to keep it longer.  It will
1852                  * be the first base object to be attempted next.
1853                  */
1854                 if (entry->delta) {
1855                         struct unpacked swap = array[best_base];
1856                         int dist = (window + idx - best_base) % window;
1857                         int dst = best_base;
1858                         while (dist--) {
1859                                 int src = (dst + 1) % window;
1860                                 array[dst] = array[src];
1861                                 dst = src;
1862                         }
1863                         array[dst] = swap;
1864                 }
1865
1866                 next:
1867                 idx++;
1868                 if (count + 1 < window)
1869                         count++;
1870                 if (idx >= window)
1871                         idx = 0;
1872         }
1873
1874         for (i = 0; i < window; ++i) {
1875                 free_delta_index(array[i].index);
1876                 free(array[i].data);
1877         }
1878         free(array);
1879 }
1880
1881 #ifndef NO_PTHREADS
1882
1883 static void try_to_free_from_threads(size_t size)
1884 {
1885         read_lock();
1886         release_pack_memory(size);
1887         read_unlock();
1888 }
1889
1890 static try_to_free_t old_try_to_free_routine;
1891
1892 /*
1893  * The main thread waits on the condition that (at least) one of the workers
1894  * has stopped working (which is indicated in the .working member of
1895  * struct thread_params).
1896  * When a work thread has completed its work, it sets .working to 0 and
1897  * signals the main thread and waits on the condition that .data_ready
1898  * becomes 1.
1899  */
1900
1901 struct thread_params {
1902         pthread_t thread;
1903         struct object_entry **list;
1904         unsigned list_size;
1905         unsigned remaining;
1906         int window;
1907         int depth;
1908         int working;
1909         int data_ready;
1910         pthread_mutex_t mutex;
1911         pthread_cond_t cond;
1912         unsigned *processed;
1913 };
1914
1915 static pthread_cond_t progress_cond;
1916
1917 /*
1918  * Mutex and conditional variable can't be statically-initialized on Windows.
1919  */
1920 static void init_threaded_search(void)
1921 {
1922         init_recursive_mutex(&read_mutex);
1923         pthread_mutex_init(&cache_mutex, NULL);
1924         pthread_mutex_init(&progress_mutex, NULL);
1925         pthread_cond_init(&progress_cond, NULL);
1926         old_try_to_free_routine = set_try_to_free_routine(try_to_free_from_threads);
1927 }
1928
1929 static void cleanup_threaded_search(void)
1930 {
1931         set_try_to_free_routine(old_try_to_free_routine);
1932         pthread_cond_destroy(&progress_cond);
1933         pthread_mutex_destroy(&read_mutex);
1934         pthread_mutex_destroy(&cache_mutex);
1935         pthread_mutex_destroy(&progress_mutex);
1936 }
1937
1938 static void *threaded_find_deltas(void *arg)
1939 {
1940         struct thread_params *me = arg;
1941
1942         while (me->remaining) {
1943                 find_deltas(me->list, &me->remaining,
1944                             me->window, me->depth, me->processed);
1945
1946                 progress_lock();
1947                 me->working = 0;
1948                 pthread_cond_signal(&progress_cond);
1949                 progress_unlock();
1950
1951                 /*
1952                  * We must not set ->data_ready before we wait on the
1953                  * condition because the main thread may have set it to 1
1954                  * before we get here. In order to be sure that new
1955                  * work is available if we see 1 in ->data_ready, it
1956                  * was initialized to 0 before this thread was spawned
1957                  * and we reset it to 0 right away.
1958                  */
1959                 pthread_mutex_lock(&me->mutex);
1960                 while (!me->data_ready)
1961                         pthread_cond_wait(&me->cond, &me->mutex);
1962                 me->data_ready = 0;
1963                 pthread_mutex_unlock(&me->mutex);
1964         }
1965         /* leave ->working 1 so that this doesn't get more work assigned */
1966         return NULL;
1967 }
1968
1969 static void ll_find_deltas(struct object_entry **list, unsigned list_size,
1970                            int window, int depth, unsigned *processed)
1971 {
1972         struct thread_params *p;
1973         int i, ret, active_threads = 0;
1974
1975         init_threaded_search();
1976
1977         if (delta_search_threads <= 1) {
1978                 find_deltas(list, &list_size, window, depth, processed);
1979                 cleanup_threaded_search();
1980                 return;
1981         }
1982         if (progress > pack_to_stdout)
1983                 fprintf(stderr, "Delta compression using up to %d threads.\n",
1984                                 delta_search_threads);
1985         p = xcalloc(delta_search_threads, sizeof(*p));
1986
1987         /* Partition the work amongst work threads. */
1988         for (i = 0; i < delta_search_threads; i++) {
1989                 unsigned sub_size = list_size / (delta_search_threads - i);
1990
1991                 /* don't use too small segments or no deltas will be found */
1992                 if (sub_size < 2*window && i+1 < delta_search_threads)
1993                         sub_size = 0;
1994
1995                 p[i].window = window;
1996                 p[i].depth = depth;
1997                 p[i].processed = processed;
1998                 p[i].working = 1;
1999                 p[i].data_ready = 0;
2000
2001                 /* try to split chunks on "path" boundaries */
2002                 while (sub_size && sub_size < list_size &&
2003                        list[sub_size]->hash &&
2004                        list[sub_size]->hash == list[sub_size-1]->hash)
2005                         sub_size++;
2006
2007                 p[i].list = list;
2008                 p[i].list_size = sub_size;
2009                 p[i].remaining = sub_size;
2010
2011                 list += sub_size;
2012                 list_size -= sub_size;
2013         }
2014
2015         /* Start work threads. */
2016         for (i = 0; i < delta_search_threads; i++) {
2017                 if (!p[i].list_size)
2018                         continue;
2019                 pthread_mutex_init(&p[i].mutex, NULL);
2020                 pthread_cond_init(&p[i].cond, NULL);
2021                 ret = pthread_create(&p[i].thread, NULL,
2022                                      threaded_find_deltas, &p[i]);
2023                 if (ret)
2024                         die("unable to create thread: %s", strerror(ret));
2025                 active_threads++;
2026         }
2027
2028         /*
2029          * Now let's wait for work completion.  Each time a thread is done
2030          * with its work, we steal half of the remaining work from the
2031          * thread with the largest number of unprocessed objects and give
2032          * it to that newly idle thread.  This ensure good load balancing
2033          * until the remaining object list segments are simply too short
2034          * to be worth splitting anymore.
2035          */
2036         while (active_threads) {
2037                 struct thread_params *target = NULL;
2038                 struct thread_params *victim = NULL;
2039                 unsigned sub_size = 0;
2040
2041                 progress_lock();
2042                 for (;;) {
2043                         for (i = 0; !target && i < delta_search_threads; i++)
2044                                 if (!p[i].working)
2045                                         target = &p[i];
2046                         if (target)
2047                                 break;
2048                         pthread_cond_wait(&progress_cond, &progress_mutex);
2049                 }
2050
2051                 for (i = 0; i < delta_search_threads; i++)
2052                         if (p[i].remaining > 2*window &&
2053                             (!victim || victim->remaining < p[i].remaining))
2054                                 victim = &p[i];
2055                 if (victim) {
2056                         sub_size = victim->remaining / 2;
2057                         list = victim->list + victim->list_size - sub_size;
2058                         while (sub_size && list[0]->hash &&
2059                                list[0]->hash == list[-1]->hash) {
2060                                 list++;
2061                                 sub_size--;
2062                         }
2063                         if (!sub_size) {
2064                                 /*
2065                                  * It is possible for some "paths" to have
2066                                  * so many objects that no hash boundary
2067                                  * might be found.  Let's just steal the
2068                                  * exact half in that case.
2069                                  */
2070                                 sub_size = victim->remaining / 2;
2071                                 list -= sub_size;
2072                         }
2073                         target->list = list;
2074                         victim->list_size -= sub_size;
2075                         victim->remaining -= sub_size;
2076                 }
2077                 target->list_size = sub_size;
2078                 target->remaining = sub_size;
2079                 target->working = 1;
2080                 progress_unlock();
2081
2082                 pthread_mutex_lock(&target->mutex);
2083                 target->data_ready = 1;
2084                 pthread_cond_signal(&target->cond);
2085                 pthread_mutex_unlock(&target->mutex);
2086
2087                 if (!sub_size) {
2088                         pthread_join(target->thread, NULL);
2089                         pthread_cond_destroy(&target->cond);
2090                         pthread_mutex_destroy(&target->mutex);
2091                         active_threads--;
2092                 }
2093         }
2094         cleanup_threaded_search();
2095         free(p);
2096 }
2097
2098 #else
2099 #define ll_find_deltas(l, s, w, d, p)   find_deltas(l, &s, w, d, p)
2100 #endif
2101
2102 static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
2103 {
2104         unsigned char peeled[20];
2105
2106         if (starts_with(path, "refs/tags/") && /* is a tag? */
2107             !peel_ref(path, peeled)        && /* peelable? */
2108             packlist_find(&to_pack, peeled, NULL))      /* object packed? */
2109                 add_object_entry(sha1, OBJ_TAG, NULL, 0);
2110         return 0;
2111 }
2112
2113 static void prepare_pack(int window, int depth)
2114 {
2115         struct object_entry **delta_list;
2116         uint32_t i, nr_deltas;
2117         unsigned n;
2118
2119         get_object_details();
2120
2121         /*
2122          * If we're locally repacking then we need to be doubly careful
2123          * from now on in order to make sure no stealth corruption gets
2124          * propagated to the new pack.  Clients receiving streamed packs
2125          * should validate everything they get anyway so no need to incur
2126          * the additional cost here in that case.
2127          */
2128         if (!pack_to_stdout)
2129                 do_check_packed_object_crc = 1;
2130
2131         if (!to_pack.nr_objects || !window || !depth)
2132                 return;
2133
2134         delta_list = xmalloc(to_pack.nr_objects * sizeof(*delta_list));
2135         nr_deltas = n = 0;
2136
2137         for (i = 0; i < to_pack.nr_objects; i++) {
2138                 struct object_entry *entry = to_pack.objects + i;
2139
2140                 if (entry->delta)
2141                         /* This happens if we decided to reuse existing
2142                          * delta from a pack.  "reuse_delta &&" is implied.
2143                          */
2144                         continue;
2145
2146                 if (entry->size < 50)
2147                         continue;
2148
2149                 if (entry->no_try_delta)
2150                         continue;
2151
2152                 if (!entry->preferred_base) {
2153                         nr_deltas++;
2154                         if (entry->type < 0)
2155                                 die("unable to get type of object %s",
2156                                     sha1_to_hex(entry->idx.sha1));
2157                 } else {
2158                         if (entry->type < 0) {
2159                                 /*
2160                                  * This object is not found, but we
2161                                  * don't have to include it anyway.
2162                                  */
2163                                 continue;
2164                         }
2165                 }
2166
2167                 delta_list[n++] = entry;
2168         }
2169
2170         if (nr_deltas && n > 1) {
2171                 unsigned nr_done = 0;
2172                 if (progress)
2173                         progress_state = start_progress(_("Compressing objects"),
2174                                                         nr_deltas);
2175                 qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
2176                 ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
2177                 stop_progress(&progress_state);
2178                 if (nr_done != nr_deltas)
2179                         die("inconsistency with delta count");
2180         }
2181         free(delta_list);
2182 }
2183
2184 static int git_pack_config(const char *k, const char *v, void *cb)
2185 {
2186         if (!strcmp(k, "pack.window")) {
2187                 window = git_config_int(k, v);
2188                 return 0;
2189         }
2190         if (!strcmp(k, "pack.windowmemory")) {
2191                 window_memory_limit = git_config_ulong(k, v);
2192                 return 0;
2193         }
2194         if (!strcmp(k, "pack.depth")) {
2195                 depth = git_config_int(k, v);
2196                 return 0;
2197         }
2198         if (!strcmp(k, "pack.compression")) {
2199                 int level = git_config_int(k, v);
2200                 if (level == -1)
2201                         level = Z_DEFAULT_COMPRESSION;
2202                 else if (level < 0 || level > Z_BEST_COMPRESSION)
2203                         die("bad pack compression level %d", level);
2204                 pack_compression_level = level;
2205                 pack_compression_seen = 1;
2206                 return 0;
2207         }
2208         if (!strcmp(k, "pack.deltacachesize")) {
2209                 max_delta_cache_size = git_config_int(k, v);
2210                 return 0;
2211         }
2212         if (!strcmp(k, "pack.deltacachelimit")) {
2213                 cache_max_small_delta_size = git_config_int(k, v);
2214                 return 0;
2215         }
2216         if (!strcmp(k, "pack.writebitmaphashcache")) {
2217                 if (git_config_bool(k, v))
2218                         write_bitmap_options |= BITMAP_OPT_HASH_CACHE;
2219                 else
2220                         write_bitmap_options &= ~BITMAP_OPT_HASH_CACHE;
2221         }
2222         if (!strcmp(k, "pack.usebitmaps")) {
2223                 use_bitmap_index = git_config_bool(k, v);
2224                 return 0;
2225         }
2226         if (!strcmp(k, "pack.threads")) {
2227                 delta_search_threads = git_config_int(k, v);
2228                 if (delta_search_threads < 0)
2229                         die("invalid number of threads specified (%d)",
2230                             delta_search_threads);
2231 #ifdef NO_PTHREADS
2232                 if (delta_search_threads != 1)
2233                         warning("no threads support, ignoring %s", k);
2234 #endif
2235                 return 0;
2236         }
2237         if (!strcmp(k, "pack.indexversion")) {
2238                 pack_idx_opts.version = git_config_int(k, v);
2239                 if (pack_idx_opts.version > 2)
2240                         die("bad pack.indexversion=%"PRIu32,
2241                             pack_idx_opts.version);
2242                 return 0;
2243         }
2244         return git_default_config(k, v, cb);
2245 }
2246
2247 static void read_object_list_from_stdin(void)
2248 {
2249         char line[40 + 1 + PATH_MAX + 2];
2250         unsigned char sha1[20];
2251
2252         for (;;) {
2253                 if (!fgets(line, sizeof(line), stdin)) {
2254                         if (feof(stdin))
2255                                 break;
2256                         if (!ferror(stdin))
2257                                 die("fgets returned NULL, not EOF, not error!");
2258                         if (errno != EINTR)
2259                                 die_errno("fgets");
2260                         clearerr(stdin);
2261                         continue;
2262                 }
2263                 if (line[0] == '-') {
2264                         if (get_sha1_hex(line+1, sha1))
2265                                 die("expected edge sha1, got garbage:\n %s",
2266                                     line);
2267                         add_preferred_base(sha1);
2268                         continue;
2269                 }
2270                 if (get_sha1_hex(line, sha1))
2271                         die("expected sha1, got garbage:\n %s", line);
2272
2273                 add_preferred_base_object(line+41);
2274                 add_object_entry(sha1, 0, line+41, 0);
2275         }
2276 }
2277
2278 #define OBJECT_ADDED (1u<<20)
2279
2280 static void show_commit(struct commit *commit, void *data)
2281 {
2282         add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
2283         commit->object.flags |= OBJECT_ADDED;
2284
2285         if (write_bitmap_index)
2286                 index_commit_for_bitmap(commit);
2287 }
2288
2289 static void show_object(struct object *obj,
2290                         const struct name_path *path, const char *last,
2291                         void *data)
2292 {
2293         char *name = path_name(path, last);
2294
2295         add_preferred_base_object(name);
2296         add_object_entry(obj->sha1, obj->type, name, 0);
2297         obj->flags |= OBJECT_ADDED;
2298
2299         /*
2300          * We will have generated the hash from the name,
2301          * but not saved a pointer to it - we can free it
2302          */
2303         free((char *)name);
2304 }
2305
2306 static void show_edge(struct commit *commit)
2307 {
2308         add_preferred_base(commit->object.sha1);
2309 }
2310
2311 struct in_pack_object {
2312         off_t offset;
2313         struct object *object;
2314 };
2315
2316 struct in_pack {
2317         int alloc;
2318         int nr;
2319         struct in_pack_object *array;
2320 };
2321
2322 static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
2323 {
2324         in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
2325         in_pack->array[in_pack->nr].object = object;
2326         in_pack->nr++;
2327 }
2328
2329 /*
2330  * Compare the objects in the offset order, in order to emulate the
2331  * "git rev-list --objects" output that produced the pack originally.
2332  */
2333 static int ofscmp(const void *a_, const void *b_)
2334 {
2335         struct in_pack_object *a = (struct in_pack_object *)a_;
2336         struct in_pack_object *b = (struct in_pack_object *)b_;
2337
2338         if (a->offset < b->offset)
2339                 return -1;
2340         else if (a->offset > b->offset)
2341                 return 1;
2342         else
2343                 return hashcmp(a->object->sha1, b->object->sha1);
2344 }
2345
2346 static void add_objects_in_unpacked_packs(struct rev_info *revs)
2347 {
2348         struct packed_git *p;
2349         struct in_pack in_pack;
2350         uint32_t i;
2351
2352         memset(&in_pack, 0, sizeof(in_pack));
2353
2354         for (p = packed_git; p; p = p->next) {
2355                 const unsigned char *sha1;
2356                 struct object *o;
2357
2358                 if (!p->pack_local || p->pack_keep)
2359                         continue;
2360                 if (open_pack_index(p))
2361                         die("cannot open pack index");
2362
2363                 ALLOC_GROW(in_pack.array,
2364                            in_pack.nr + p->num_objects,
2365                            in_pack.alloc);
2366
2367                 for (i = 0; i < p->num_objects; i++) {
2368                         sha1 = nth_packed_object_sha1(p, i);
2369                         o = lookup_unknown_object(sha1);
2370                         if (!(o->flags & OBJECT_ADDED))
2371                                 mark_in_pack_object(o, p, &in_pack);
2372                         o->flags |= OBJECT_ADDED;
2373                 }
2374         }
2375
2376         if (in_pack.nr) {
2377                 qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
2378                       ofscmp);
2379                 for (i = 0; i < in_pack.nr; i++) {
2380                         struct object *o = in_pack.array[i].object;
2381                         add_object_entry(o->sha1, o->type, "", 0);
2382                 }
2383         }
2384         free(in_pack.array);
2385 }
2386
2387 static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
2388 {
2389         static struct packed_git *last_found = (void *)1;
2390         struct packed_git *p;
2391
2392         p = (last_found != (void *)1) ? last_found : packed_git;
2393
2394         while (p) {
2395                 if ((!p->pack_local || p->pack_keep) &&
2396                         find_pack_entry_one(sha1, p)) {
2397                         last_found = p;
2398                         return 1;
2399                 }
2400                 if (p == last_found)
2401                         p = packed_git;
2402                 else
2403                         p = p->next;
2404                 if (p == last_found)
2405                         p = p->next;
2406         }
2407         return 0;
2408 }
2409
2410 /*
2411  * Store a list of sha1s that are should not be discarded
2412  * because they are either written too recently, or are
2413  * reachable from another object that was.
2414  *
2415  * This is filled by get_object_list.
2416  */
2417 static struct sha1_array recent_objects;
2418
2419 static int loosened_object_can_be_discarded(const unsigned char *sha1,
2420                                             unsigned long mtime)
2421 {
2422         if (!unpack_unreachable_expiration)
2423                 return 0;
2424         if (mtime > unpack_unreachable_expiration)
2425                 return 0;
2426         if (sha1_array_lookup(&recent_objects, sha1) >= 0)
2427                 return 0;
2428         return 1;
2429 }
2430
2431 static void loosen_unused_packed_objects(struct rev_info *revs)
2432 {
2433         struct packed_git *p;
2434         uint32_t i;
2435         const unsigned char *sha1;
2436
2437         for (p = packed_git; p; p = p->next) {
2438                 if (!p->pack_local || p->pack_keep)
2439                         continue;
2440
2441                 if (open_pack_index(p))
2442                         die("cannot open pack index");
2443
2444                 for (i = 0; i < p->num_objects; i++) {
2445                         sha1 = nth_packed_object_sha1(p, i);
2446                         if (!packlist_find(&to_pack, sha1, NULL) &&
2447                             !has_sha1_pack_kept_or_nonlocal(sha1) &&
2448                             !loosened_object_can_be_discarded(sha1, p->mtime))
2449                                 if (force_object_loose(sha1, p->mtime))
2450                                         die("unable to force loose object");
2451                 }
2452         }
2453 }
2454
2455 /*
2456  * This tracks any options which a reader of the pack might
2457  * not understand, and which would therefore prevent blind reuse
2458  * of what we have on disk.
2459  */
2460 static int pack_options_allow_reuse(void)
2461 {
2462         return allow_ofs_delta;
2463 }
2464
2465 static int get_object_list_from_bitmap(struct rev_info *revs)
2466 {
2467         if (prepare_bitmap_walk(revs) < 0)
2468                 return -1;
2469
2470         if (pack_options_allow_reuse() &&
2471             !reuse_partial_packfile_from_bitmap(
2472                         &reuse_packfile,
2473                         &reuse_packfile_objects,
2474                         &reuse_packfile_offset)) {
2475                 assert(reuse_packfile_objects);
2476                 nr_result += reuse_packfile_objects;
2477                 display_progress(progress_state, nr_result);
2478         }
2479
2480         traverse_bitmap_commit_list(&add_object_entry_from_bitmap);
2481         return 0;
2482 }
2483
2484 static void record_recent_object(struct object *obj,
2485                                  const struct name_path *path,
2486                                  const char *last,
2487                                  void *data)
2488 {
2489         sha1_array_append(&recent_objects, obj->sha1);
2490 }
2491
2492 static void record_recent_commit(struct commit *commit, void *data)
2493 {
2494         sha1_array_append(&recent_objects, commit->object.sha1);
2495 }
2496
2497 static void get_object_list(int ac, const char **av)
2498 {
2499         struct rev_info revs;
2500         char line[1000];
2501         int flags = 0;
2502
2503         init_revisions(&revs, NULL);
2504         save_commit_buffer = 0;
2505         setup_revisions(ac, av, &revs, NULL);
2506
2507         /* make sure shallows are read */
2508         is_repository_shallow();
2509
2510         while (fgets(line, sizeof(line), stdin) != NULL) {
2511                 int len = strlen(line);
2512                 if (len && line[len - 1] == '\n')
2513                         line[--len] = 0;
2514                 if (!len)
2515                         break;
2516                 if (*line == '-') {
2517                         if (!strcmp(line, "--not")) {
2518                                 flags ^= UNINTERESTING;
2519                                 write_bitmap_index = 0;
2520                                 continue;
2521                         }
2522                         if (starts_with(line, "--shallow ")) {
2523                                 unsigned char sha1[20];
2524                                 if (get_sha1_hex(line + 10, sha1))
2525                                         die("not an SHA-1 '%s'", line + 10);
2526                                 register_shallow(sha1);
2527                                 use_bitmap_index = 0;
2528                                 continue;
2529                         }
2530                         die("not a rev '%s'", line);
2531                 }
2532                 if (handle_revision_arg(line, &revs, flags, REVARG_CANNOT_BE_FILENAME))
2533                         die("bad revision '%s'", line);
2534         }
2535
2536         if (use_bitmap_index && !get_object_list_from_bitmap(&revs))
2537                 return;
2538
2539         if (prepare_revision_walk(&revs))
2540                 die("revision walk setup failed");
2541         mark_edges_uninteresting(&revs, show_edge);
2542         traverse_commit_list(&revs, show_commit, show_object, NULL);
2543
2544         if (unpack_unreachable_expiration) {
2545                 revs.ignore_missing_links = 1;
2546                 if (add_unseen_recent_objects_to_traversal(&revs,
2547                                 unpack_unreachable_expiration))
2548                         die("unable to add recent objects");
2549                 if (prepare_revision_walk(&revs))
2550                         die("revision walk setup failed");
2551                 traverse_commit_list(&revs, record_recent_commit,
2552                                      record_recent_object, NULL);
2553         }
2554
2555         if (keep_unreachable)
2556                 add_objects_in_unpacked_packs(&revs);
2557         if (unpack_unreachable)
2558                 loosen_unused_packed_objects(&revs);
2559
2560         sha1_array_clear(&recent_objects);
2561 }
2562
2563 static int option_parse_index_version(const struct option *opt,
2564                                       const char *arg, int unset)
2565 {
2566         char *c;
2567         const char *val = arg;
2568         pack_idx_opts.version = strtoul(val, &c, 10);
2569         if (pack_idx_opts.version > 2)
2570                 die(_("unsupported index version %s"), val);
2571         if (*c == ',' && c[1])
2572                 pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
2573         if (*c || pack_idx_opts.off32_limit & 0x80000000)
2574                 die(_("bad index version '%s'"), val);
2575         return 0;
2576 }
2577
2578 static int option_parse_unpack_unreachable(const struct option *opt,
2579                                            const char *arg, int unset)
2580 {
2581         if (unset) {
2582                 unpack_unreachable = 0;
2583                 unpack_unreachable_expiration = 0;
2584         }
2585         else {
2586                 unpack_unreachable = 1;
2587                 if (arg)
2588                         unpack_unreachable_expiration = approxidate(arg);
2589         }
2590         return 0;
2591 }
2592
2593 static int option_parse_ulong(const struct option *opt,
2594                               const char *arg, int unset)
2595 {
2596         if (unset)
2597                 die(_("option %s does not accept negative form"),
2598                     opt->long_name);
2599
2600         if (!git_parse_ulong(arg, opt->value))
2601                 die(_("unable to parse value '%s' for option %s"),
2602                     arg, opt->long_name);
2603         return 0;
2604 }
2605
2606 #define OPT_ULONG(s, l, v, h) \
2607         { OPTION_CALLBACK, (s), (l), (v), "n", (h),     \
2608           PARSE_OPT_NONEG, option_parse_ulong }
2609
2610 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
2611 {
2612         int use_internal_rev_list = 0;
2613         int thin = 0;
2614         int shallow = 0;
2615         int all_progress_implied = 0;
2616         struct argv_array rp = ARGV_ARRAY_INIT;
2617         int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
2618         int rev_list_index = 0;
2619         struct option pack_objects_options[] = {
2620                 OPT_SET_INT('q', "quiet", &progress,
2621                             N_("do not show progress meter"), 0),
2622                 OPT_SET_INT(0, "progress", &progress,
2623                             N_("show progress meter"), 1),
2624                 OPT_SET_INT(0, "all-progress", &progress,
2625                             N_("show progress meter during object writing phase"), 2),
2626                 OPT_BOOL(0, "all-progress-implied",
2627                          &all_progress_implied,
2628                          N_("similar to --all-progress when progress meter is shown")),
2629                 { OPTION_CALLBACK, 0, "index-version", NULL, N_("version[,offset]"),
2630                   N_("write the pack index file in the specified idx format version"),
2631                   0, option_parse_index_version },
2632                 OPT_ULONG(0, "max-pack-size", &pack_size_limit,
2633                           N_("maximum size of each output pack file")),
2634                 OPT_BOOL(0, "local", &local,
2635                          N_("ignore borrowed objects from alternate object store")),
2636                 OPT_BOOL(0, "incremental", &incremental,
2637                          N_("ignore packed objects")),
2638                 OPT_INTEGER(0, "window", &window,
2639                             N_("limit pack window by objects")),
2640                 OPT_ULONG(0, "window-memory", &window_memory_limit,
2641                           N_("limit pack window by memory in addition to object limit")),
2642                 OPT_INTEGER(0, "depth", &depth,
2643                             N_("maximum length of delta chain allowed in the resulting pack")),
2644                 OPT_BOOL(0, "reuse-delta", &reuse_delta,
2645                          N_("reuse existing deltas")),
2646                 OPT_BOOL(0, "reuse-object", &reuse_object,
2647                          N_("reuse existing objects")),
2648                 OPT_BOOL(0, "delta-base-offset", &allow_ofs_delta,
2649                          N_("use OFS_DELTA objects")),
2650                 OPT_INTEGER(0, "threads", &delta_search_threads,
2651                             N_("use threads when searching for best delta matches")),
2652                 OPT_BOOL(0, "non-empty", &non_empty,
2653                          N_("do not create an empty pack output")),
2654                 OPT_BOOL(0, "revs", &use_internal_rev_list,
2655                          N_("read revision arguments from standard input")),
2656                 { OPTION_SET_INT, 0, "unpacked", &rev_list_unpacked, NULL,
2657                   N_("limit the objects to those that are not yet packed"),
2658                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2659                 { OPTION_SET_INT, 0, "all", &rev_list_all, NULL,
2660                   N_("include objects reachable from any reference"),
2661                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2662                 { OPTION_SET_INT, 0, "reflog", &rev_list_reflog, NULL,
2663                   N_("include objects referred by reflog entries"),
2664                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2665                 { OPTION_SET_INT, 0, "indexed-objects", &rev_list_index, NULL,
2666                   N_("include objects referred to by the index"),
2667                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
2668                 OPT_BOOL(0, "stdout", &pack_to_stdout,
2669                          N_("output pack to stdout")),
2670                 OPT_BOOL(0, "include-tag", &include_tag,
2671                          N_("include tag objects that refer to objects to be packed")),
2672                 OPT_BOOL(0, "keep-unreachable", &keep_unreachable,
2673                          N_("keep unreachable objects")),
2674                 { OPTION_CALLBACK, 0, "unpack-unreachable", NULL, N_("time"),
2675                   N_("unpack unreachable objects newer than <time>"),
2676                   PARSE_OPT_OPTARG, option_parse_unpack_unreachable },
2677                 OPT_BOOL(0, "thin", &thin,
2678                          N_("create thin packs")),
2679                 OPT_BOOL(0, "shallow", &shallow,
2680                          N_("create packs suitable for shallow fetches")),
2681                 OPT_BOOL(0, "honor-pack-keep", &ignore_packed_keep,
2682                          N_("ignore packs that have companion .keep file")),
2683                 OPT_INTEGER(0, "compression", &pack_compression_level,
2684                             N_("pack compression level")),
2685                 OPT_SET_INT(0, "keep-true-parents", &grafts_replace_parents,
2686                             N_("do not hide commits by grafts"), 0),
2687                 OPT_BOOL(0, "use-bitmap-index", &use_bitmap_index,
2688                          N_("use a bitmap index if available to speed up counting objects")),
2689                 OPT_BOOL(0, "write-bitmap-index", &write_bitmap_index,
2690                          N_("write a bitmap index together with the pack index")),
2691                 OPT_END(),
2692         };
2693
2694         check_replace_refs = 0;
2695
2696         reset_pack_idx_option(&pack_idx_opts);
2697         git_config(git_pack_config, NULL);
2698         if (!pack_compression_seen && core_compression_seen)
2699                 pack_compression_level = core_compression_level;
2700
2701         progress = isatty(2);
2702         argc = parse_options(argc, argv, prefix, pack_objects_options,
2703                              pack_usage, 0);
2704
2705         if (argc) {
2706                 base_name = argv[0];
2707                 argc--;
2708         }
2709         if (pack_to_stdout != !base_name || argc)
2710                 usage_with_options(pack_usage, pack_objects_options);
2711
2712         argv_array_push(&rp, "pack-objects");
2713         if (thin) {
2714                 use_internal_rev_list = 1;
2715                 argv_array_push(&rp, shallow
2716                                 ? "--objects-edge-aggressive"
2717                                 : "--objects-edge");
2718         } else
2719                 argv_array_push(&rp, "--objects");
2720
2721         if (rev_list_all) {
2722                 use_internal_rev_list = 1;
2723                 argv_array_push(&rp, "--all");
2724         }
2725         if (rev_list_reflog) {
2726                 use_internal_rev_list = 1;
2727                 argv_array_push(&rp, "--reflog");
2728         }
2729         if (rev_list_index) {
2730                 use_internal_rev_list = 1;
2731                 argv_array_push(&rp, "--indexed-objects");
2732         }
2733         if (rev_list_unpacked) {
2734                 use_internal_rev_list = 1;
2735                 argv_array_push(&rp, "--unpacked");
2736         }
2737
2738         if (!reuse_object)
2739                 reuse_delta = 0;
2740         if (pack_compression_level == -1)
2741                 pack_compression_level = Z_DEFAULT_COMPRESSION;
2742         else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
2743                 die("bad pack compression level %d", pack_compression_level);
2744
2745         if (!delta_search_threads)      /* --threads=0 means autodetect */
2746                 delta_search_threads = online_cpus();
2747
2748 #ifdef NO_PTHREADS
2749         if (delta_search_threads != 1)
2750                 warning("no threads support, ignoring --threads");
2751 #endif
2752         if (!pack_to_stdout && !pack_size_limit)
2753                 pack_size_limit = pack_size_limit_cfg;
2754         if (pack_to_stdout && pack_size_limit)
2755                 die("--max-pack-size cannot be used to build a pack for transfer.");
2756         if (pack_size_limit && pack_size_limit < 1024*1024) {
2757                 warning("minimum pack size limit is 1 MiB");
2758                 pack_size_limit = 1024*1024;
2759         }
2760
2761         if (!pack_to_stdout && thin)
2762                 die("--thin cannot be used to build an indexable pack.");
2763
2764         if (keep_unreachable && unpack_unreachable)
2765                 die("--keep-unreachable and --unpack-unreachable are incompatible.");
2766         if (!rev_list_all || !rev_list_reflog || !rev_list_index)
2767                 unpack_unreachable_expiration = 0;
2768
2769         if (!use_internal_rev_list || !pack_to_stdout || is_repository_shallow())
2770                 use_bitmap_index = 0;
2771
2772         if (pack_to_stdout || !rev_list_all)
2773                 write_bitmap_index = 0;
2774
2775         if (progress && all_progress_implied)
2776                 progress = 2;
2777
2778         prepare_packed_git();
2779
2780         if (progress)
2781                 progress_state = start_progress(_("Counting objects"), 0);
2782         if (!use_internal_rev_list)
2783                 read_object_list_from_stdin();
2784         else {
2785                 get_object_list(rp.argc, rp.argv);
2786                 argv_array_clear(&rp);
2787         }
2788         cleanup_preferred_base();
2789         if (include_tag && nr_result)
2790                 for_each_ref(add_ref_tag, NULL);
2791         stop_progress(&progress_state);
2792
2793         if (non_empty && !nr_result)
2794                 return 0;
2795         if (nr_result)
2796                 prepare_pack(window, depth);
2797         write_pack_file();
2798         if (progress)
2799                 fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
2800                         " reused %"PRIu32" (delta %"PRIu32")\n",
2801                         written, written_delta, reused, reused_delta);
2802         return 0;
2803 }