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