Merge branch 'jc/leftright'
[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
16 static const char pack_usage[] = "\
17 git-pack-objects [{ -q | --progress | --all-progress }] \n\
18         [--local] [--incremental] [--window=N] [--depth=N] \n\
19         [--no-reuse-delta] [--delta-base-offset] [--non-empty] \n\
20         [--revs [--unpacked | --all]*] [--stdout | base-name] \n\
21         [<ref-list | <object-list]";
22
23 struct object_entry {
24         unsigned char sha1[20];
25         unsigned long size;     /* uncompressed size */
26         unsigned long offset;   /* offset into the final pack file;
27                                  * nonzero if already written.
28                                  */
29         unsigned int depth;     /* delta depth */
30         unsigned int delta_limit;       /* base adjustment for in-pack delta */
31         unsigned int hash;      /* name hint hash */
32         enum object_type type;
33         enum object_type in_pack_type;  /* could be delta */
34         unsigned long delta_size;       /* delta data size (uncompressed) */
35 #define in_pack_header_size delta_size  /* only when reusing pack data */
36         struct object_entry *delta;     /* delta base object */
37         struct packed_git *in_pack;     /* already in pack */
38         unsigned int in_pack_offset;
39         struct object_entry *delta_child; /* deltified objects who bases me */
40         struct object_entry *delta_sibling; /* other deltified objects who
41                                              * uses the same base as me
42                                              */
43         int preferred_base;     /* we do not pack this, but is encouraged to
44                                  * be used as the base objectto delta huge
45                                  * objects against.
46                                  */
47 };
48
49 /*
50  * Objects we are going to pack are collected in objects array (dynamically
51  * expanded).  nr_objects & nr_alloc controls this array.  They are stored
52  * in the order we see -- typically rev-list --objects order that gives us
53  * nice "minimum seek" order.
54  *
55  * sorted-by-sha ans sorted-by-type are arrays of pointers that point at
56  * elements in the objects array.  The former is used to build the pack
57  * index (lists object names in the ascending order to help offset lookup),
58  * and the latter is used to group similar things together by try_delta()
59  * heuristics.
60  */
61
62 static unsigned char object_list_sha1[20];
63 static int non_empty;
64 static int no_reuse_delta;
65 static int local;
66 static int incremental;
67 static int allow_ofs_delta;
68
69 static struct object_entry **sorted_by_sha, **sorted_by_type;
70 static struct object_entry *objects;
71 static int nr_objects, nr_alloc, nr_result;
72 static const char *base_name;
73 static unsigned char pack_file_sha1[20];
74 static int progress = 1;
75 static volatile sig_atomic_t progress_update;
76 static int window = 10;
77 static int pack_to_stdout;
78 static int num_preferred_base;
79
80 /*
81  * The object names in objects array are hashed with this hashtable,
82  * to help looking up the entry by object name.  Binary search from
83  * sorted_by_sha is also possible but this was easier to code and faster.
84  * This hashtable is built after all the objects are seen.
85  */
86 static int *object_ix;
87 static int object_ix_hashsz;
88
89 /*
90  * Pack index for existing packs give us easy access to the offsets into
91  * corresponding pack file where each object's data starts, but the entries
92  * do not store the size of the compressed representation (uncompressed
93  * size is easily available by examining the pack entry header).  It is
94  * also rather expensive to find the sha1 for an object given its offset.
95  *
96  * We build a hashtable of existing packs (pack_revindex), and keep reverse
97  * index here -- pack index file is sorted by object name mapping to offset;
98  * this pack_revindex[].revindex array is a list of offset/index_nr pairs
99  * ordered by offset, so if you know the offset of an object, next offset
100  * is where its packed representation ends and the index_nr can be used to
101  * get the object sha1 from the main index.
102  */
103 struct revindex_entry {
104         unsigned int offset;
105         unsigned int nr;
106 };
107 struct pack_revindex {
108         struct packed_git *p;
109         struct revindex_entry *revindex;
110 };
111 static struct  pack_revindex *pack_revindex;
112 static int pack_revindex_hashsz;
113
114 /*
115  * stats
116  */
117 static int written;
118 static int written_delta;
119 static int reused;
120 static int reused_delta;
121
122 static int pack_revindex_ix(struct packed_git *p)
123 {
124         unsigned long ui = (unsigned long)p;
125         int i;
126
127         ui = ui ^ (ui >> 16); /* defeat structure alignment */
128         i = (int)(ui % pack_revindex_hashsz);
129         while (pack_revindex[i].p) {
130                 if (pack_revindex[i].p == p)
131                         return i;
132                 if (++i == pack_revindex_hashsz)
133                         i = 0;
134         }
135         return -1 - i;
136 }
137
138 static void prepare_pack_ix(void)
139 {
140         int num;
141         struct packed_git *p;
142         for (num = 0, p = packed_git; p; p = p->next)
143                 num++;
144         if (!num)
145                 return;
146         pack_revindex_hashsz = num * 11;
147         pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
148         for (p = packed_git; p; p = p->next) {
149                 num = pack_revindex_ix(p);
150                 num = - 1 - num;
151                 pack_revindex[num].p = p;
152         }
153         /* revindex elements are lazily initialized */
154 }
155
156 static int cmp_offset(const void *a_, const void *b_)
157 {
158         const struct revindex_entry *a = a_;
159         const struct revindex_entry *b = b_;
160         return (a->offset < b->offset) ? -1 : (a->offset > b->offset) ? 1 : 0;
161 }
162
163 /*
164  * Ordered list of offsets of objects in the pack.
165  */
166 static void prepare_pack_revindex(struct pack_revindex *rix)
167 {
168         struct packed_git *p = rix->p;
169         int num_ent = num_packed_objects(p);
170         int i;
171         void *index = p->index_base + 256;
172
173         rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1));
174         for (i = 0; i < num_ent; i++) {
175                 unsigned int hl = *((unsigned int *)((char *) index + 24*i));
176                 rix->revindex[i].offset = ntohl(hl);
177                 rix->revindex[i].nr = i;
178         }
179         /* This knows the pack format -- the 20-byte trailer
180          * follows immediately after the last object data.
181          */
182         rix->revindex[num_ent].offset = p->pack_size - 20;
183         rix->revindex[num_ent].nr = -1;
184         qsort(rix->revindex, num_ent, sizeof(*rix->revindex), cmp_offset);
185 }
186
187 static struct revindex_entry * find_packed_object(struct packed_git *p,
188                                                   unsigned int ofs)
189 {
190         int num;
191         int lo, hi;
192         struct pack_revindex *rix;
193         struct revindex_entry *revindex;
194         num = pack_revindex_ix(p);
195         if (num < 0)
196                 die("internal error: pack revindex uninitialized");
197         rix = &pack_revindex[num];
198         if (!rix->revindex)
199                 prepare_pack_revindex(rix);
200         revindex = rix->revindex;
201         lo = 0;
202         hi = num_packed_objects(p) + 1;
203         do {
204                 int mi = (lo + hi) / 2;
205                 if (revindex[mi].offset == ofs) {
206                         return revindex + mi;
207                 }
208                 else if (ofs < revindex[mi].offset)
209                         hi = mi;
210                 else
211                         lo = mi + 1;
212         } while (lo < hi);
213         die("internal error: pack revindex corrupt");
214 }
215
216 static unsigned long find_packed_object_size(struct packed_git *p,
217                                              unsigned long ofs)
218 {
219         struct revindex_entry *entry = find_packed_object(p, ofs);
220         return entry[1].offset - ofs;
221 }
222
223 static unsigned char *find_packed_object_name(struct packed_git *p,
224                                               unsigned long ofs)
225 {
226         struct revindex_entry *entry = find_packed_object(p, ofs);
227         return (unsigned char *)(p->index_base + 256) + 24 * entry->nr + 4;
228 }
229
230 static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
231 {
232         unsigned long othersize, delta_size;
233         char type[10];
234         void *otherbuf = read_sha1_file(entry->delta->sha1, type, &othersize);
235         void *delta_buf;
236
237         if (!otherbuf)
238                 die("unable to read %s", sha1_to_hex(entry->delta->sha1));
239         delta_buf = diff_delta(otherbuf, othersize,
240                                buf, size, &delta_size, 0);
241         if (!delta_buf || delta_size != entry->delta_size)
242                 die("delta size changed");
243         free(buf);
244         free(otherbuf);
245         return delta_buf;
246 }
247
248 /*
249  * The per-object header is a pretty dense thing, which is
250  *  - first byte: low four bits are "size", then three bits of "type",
251  *    and the high bit is "size continues".
252  *  - each byte afterwards: low seven bits are size continuation,
253  *    with the high bit being "size continues"
254  */
255 static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
256 {
257         int n = 1;
258         unsigned char c;
259
260         if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
261                 die("bad type %d", type);
262
263         c = (type << 4) | (size & 15);
264         size >>= 4;
265         while (size) {
266                 *hdr++ = c | 0x80;
267                 c = size & 0x7f;
268                 size >>= 7;
269                 n++;
270         }
271         *hdr = c;
272         return n;
273 }
274
275 /*
276  * we are going to reuse the existing object data as is.  make
277  * sure it is not corrupt.
278  */
279 static int check_inflate(unsigned char *data, unsigned long len, unsigned long expect)
280 {
281         z_stream stream;
282         unsigned char fakebuf[4096];
283         int st;
284
285         memset(&stream, 0, sizeof(stream));
286         stream.next_in = data;
287         stream.avail_in = len;
288         stream.next_out = fakebuf;
289         stream.avail_out = sizeof(fakebuf);
290         inflateInit(&stream);
291
292         while (1) {
293                 st = inflate(&stream, Z_FINISH);
294                 if (st == Z_STREAM_END || st == Z_OK) {
295                         st = (stream.total_out == expect &&
296                               stream.total_in == len) ? 0 : -1;
297                         break;
298                 }
299                 if (st != Z_BUF_ERROR) {
300                         st = -1;
301                         break;
302                 }
303                 stream.next_out = fakebuf;
304                 stream.avail_out = sizeof(fakebuf);
305         }
306         inflateEnd(&stream);
307         return st;
308 }
309
310 static int revalidate_loose_object(struct object_entry *entry,
311                                    unsigned char *map,
312                                    unsigned long mapsize)
313 {
314         /* we already know this is a loose object with new type header. */
315         enum object_type type;
316         unsigned long size, used;
317
318         if (pack_to_stdout)
319                 return 0;
320
321         used = unpack_object_header_gently(map, mapsize, &type, &size);
322         if (!used)
323                 return -1;
324         map += used;
325         mapsize -= used;
326         return check_inflate(map, mapsize, size);
327 }
328
329 static unsigned long write_object(struct sha1file *f,
330                                   struct object_entry *entry)
331 {
332         unsigned long size;
333         char type[10];
334         void *buf;
335         unsigned char header[10];
336         unsigned hdrlen, datalen;
337         enum object_type obj_type;
338         int to_reuse = 0;
339
340         obj_type = entry->type;
341         if (! entry->in_pack)
342                 to_reuse = 0;   /* can't reuse what we don't have */
343         else if (obj_type == OBJ_REF_DELTA || obj_type == OBJ_OFS_DELTA)
344                 to_reuse = 1;   /* check_object() decided it for us */
345         else if (obj_type != entry->in_pack_type)
346                 to_reuse = 0;   /* pack has delta which is unusable */
347         else if (entry->delta)
348                 to_reuse = 0;   /* we want to pack afresh */
349         else
350                 to_reuse = 1;   /* we have it in-pack undeltified,
351                                  * and we do not need to deltify it.
352                                  */
353
354         if (!entry->in_pack && !entry->delta) {
355                 unsigned char *map;
356                 unsigned long mapsize;
357                 map = map_sha1_file(entry->sha1, &mapsize);
358                 if (map && !legacy_loose_object(map)) {
359                         /* We can copy straight into the pack file */
360                         if (revalidate_loose_object(entry, map, mapsize))
361                                 die("corrupt loose object %s",
362                                     sha1_to_hex(entry->sha1));
363                         sha1write(f, map, mapsize);
364                         munmap(map, mapsize);
365                         written++;
366                         reused++;
367                         return mapsize;
368                 }
369                 if (map)
370                         munmap(map, mapsize);
371         }
372
373         if (!to_reuse) {
374                 buf = read_sha1_file(entry->sha1, type, &size);
375                 if (!buf)
376                         die("unable to read %s", sha1_to_hex(entry->sha1));
377                 if (size != entry->size)
378                         die("object %s size inconsistency (%lu vs %lu)",
379                             sha1_to_hex(entry->sha1), size, entry->size);
380                 if (entry->delta) {
381                         buf = delta_against(buf, size, entry);
382                         size = entry->delta_size;
383                         obj_type = (allow_ofs_delta && entry->delta->offset) ?
384                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
385                 }
386                 /*
387                  * The object header is a byte of 'type' followed by zero or
388                  * more bytes of length.
389                  */
390                 hdrlen = encode_header(obj_type, size, header);
391                 sha1write(f, header, hdrlen);
392
393                 if (obj_type == OBJ_OFS_DELTA) {
394                         /*
395                          * Deltas with relative base contain an additional
396                          * encoding of the relative offset for the delta
397                          * base from this object's position in the pack.
398                          */
399                         unsigned long ofs = entry->offset - entry->delta->offset;
400                         unsigned pos = sizeof(header) - 1;
401                         header[pos] = ofs & 127;
402                         while (ofs >>= 7)
403                                 header[--pos] = 128 | (--ofs & 127);
404                         sha1write(f, header + pos, sizeof(header) - pos);
405                         hdrlen += sizeof(header) - pos;
406                 } else if (obj_type == OBJ_REF_DELTA) {
407                         /*
408                          * Deltas with a base reference contain
409                          * an additional 20 bytes for the base sha1.
410                          */
411                         sha1write(f, entry->delta->sha1, 20);
412                         hdrlen += 20;
413                 }
414                 datalen = sha1write_compressed(f, buf, size);
415                 free(buf);
416         }
417         else {
418                 struct packed_git *p = entry->in_pack;
419
420                 if (entry->delta) {
421                         obj_type = (allow_ofs_delta && entry->delta->offset) ?
422                                 OBJ_OFS_DELTA : OBJ_REF_DELTA;
423                         reused_delta++;
424                 }
425                 hdrlen = encode_header(obj_type, entry->size, header);
426                 sha1write(f, header, hdrlen);
427                 if (obj_type == OBJ_OFS_DELTA) {
428                         unsigned long ofs = entry->offset - entry->delta->offset;
429                         unsigned pos = sizeof(header) - 1;
430                         header[pos] = ofs & 127;
431                         while (ofs >>= 7)
432                                 header[--pos] = 128 | (--ofs & 127);
433                         sha1write(f, header + pos, sizeof(header) - pos);
434                         hdrlen += sizeof(header) - pos;
435                 } else if (obj_type == OBJ_REF_DELTA) {
436                         sha1write(f, entry->delta->sha1, 20);
437                         hdrlen += 20;
438                 }
439
440                 use_packed_git(p);
441                 buf = (char *) p->pack_base
442                         + entry->in_pack_offset
443                         + entry->in_pack_header_size;
444                 datalen = find_packed_object_size(p, entry->in_pack_offset)
445                                 - entry->in_pack_header_size;
446                 if (!pack_to_stdout && check_inflate(buf, datalen, entry->size))
447                         die("corrupt delta in pack %s", sha1_to_hex(entry->sha1));
448                 sha1write(f, buf, datalen);
449                 unuse_packed_git(p);
450                 reused++;
451         }
452         if (entry->delta)
453                 written_delta++;
454         written++;
455         return hdrlen + datalen;
456 }
457
458 static unsigned long write_one(struct sha1file *f,
459                                struct object_entry *e,
460                                unsigned long offset)
461 {
462         if (e->offset || e->preferred_base)
463                 /* offset starts from header size and cannot be zero
464                  * if it is written already.
465                  */
466                 return offset;
467         /* if we are deltified, write out its base object first. */
468         if (e->delta)
469                 offset = write_one(f, e->delta, offset);
470         e->offset = offset;
471         return offset + write_object(f, e);
472 }
473
474 static void write_pack_file(void)
475 {
476         int i;
477         struct sha1file *f;
478         unsigned long offset;
479         struct pack_header hdr;
480         unsigned last_percent = 999;
481         int do_progress = progress;
482
483         if (!base_name) {
484                 f = sha1fd(1, "<stdout>");
485                 do_progress >>= 1;
486         }
487         else
488                 f = sha1create("%s-%s.%s", base_name,
489                                sha1_to_hex(object_list_sha1), "pack");
490         if (do_progress)
491                 fprintf(stderr, "Writing %d objects.\n", nr_result);
492
493         hdr.hdr_signature = htonl(PACK_SIGNATURE);
494         hdr.hdr_version = htonl(PACK_VERSION);
495         hdr.hdr_entries = htonl(nr_result);
496         sha1write(f, &hdr, sizeof(hdr));
497         offset = sizeof(hdr);
498         if (!nr_result)
499                 goto done;
500         for (i = 0; i < nr_objects; i++) {
501                 offset = write_one(f, objects + i, offset);
502                 if (do_progress) {
503                         unsigned percent = written * 100 / nr_result;
504                         if (progress_update || percent != last_percent) {
505                                 fprintf(stderr, "%4u%% (%u/%u) done\r",
506                                         percent, written, nr_result);
507                                 progress_update = 0;
508                                 last_percent = percent;
509                         }
510                 }
511         }
512         if (do_progress)
513                 fputc('\n', stderr);
514  done:
515         if (written != nr_result)
516                 die("wrote %d objects while expecting %d", written, nr_result);
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             trg_entry->in_pack_type != OBJ_REF_DELTA &&
1181             trg_entry->in_pack_type != OBJ_OFS_DELTA)
1182                 return 0;
1183
1184         /*
1185          * If the current object is at pack edge, take the depth the
1186          * objects that depend on the current object into account --
1187          * otherwise they would become too deep.
1188          */
1189         if (trg_entry->delta_child) {
1190                 if (max_depth <= trg_entry->delta_limit)
1191                         return 0;
1192                 max_depth -= trg_entry->delta_limit;
1193         }
1194         if (src_entry->depth >= max_depth)
1195                 return 0;
1196
1197         /* Now some size filtering heuristics. */
1198         trg_size = trg_entry->size;
1199         max_size = trg_size/2 - 20;
1200         max_size = max_size * (max_depth - src_entry->depth) / max_depth;
1201         if (max_size == 0)
1202                 return 0;
1203         if (trg_entry->delta && trg_entry->delta_size <= max_size)
1204                 max_size = trg_entry->delta_size-1;
1205         src_size = src_entry->size;
1206         sizediff = src_size < trg_size ? trg_size - src_size : 0;
1207         if (sizediff >= max_size)
1208                 return 0;
1209
1210         /* Load data if not already done */
1211         if (!trg->data) {
1212                 trg->data = read_sha1_file(trg_entry->sha1, type, &sz);
1213                 if (sz != trg_size)
1214                         die("object %s inconsistent object length (%lu vs %lu)",
1215                             sha1_to_hex(trg_entry->sha1), sz, trg_size);
1216         }
1217         if (!src->data) {
1218                 src->data = read_sha1_file(src_entry->sha1, type, &sz);
1219                 if (sz != src_size)
1220                         die("object %s inconsistent object length (%lu vs %lu)",
1221                             sha1_to_hex(src_entry->sha1), sz, src_size);
1222         }
1223         if (!src->index) {
1224                 src->index = create_delta_index(src->data, src_size);
1225                 if (!src->index)
1226                         die("out of memory");
1227         }
1228
1229         delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
1230         if (!delta_buf)
1231                 return 0;
1232
1233         trg_entry->delta = src_entry;
1234         trg_entry->delta_size = delta_size;
1235         trg_entry->depth = src_entry->depth + 1;
1236         free(delta_buf);
1237         return 1;
1238 }
1239
1240 static void progress_interval(int signum)
1241 {
1242         progress_update = 1;
1243 }
1244
1245 static void find_deltas(struct object_entry **list, int window, int depth)
1246 {
1247         int i, idx;
1248         unsigned int array_size = window * sizeof(struct unpacked);
1249         struct unpacked *array = xmalloc(array_size);
1250         unsigned processed = 0;
1251         unsigned last_percent = 999;
1252
1253         memset(array, 0, array_size);
1254         i = nr_objects;
1255         idx = 0;
1256         if (progress)
1257                 fprintf(stderr, "Deltifying %d objects.\n", nr_result);
1258
1259         while (--i >= 0) {
1260                 struct object_entry *entry = list[i];
1261                 struct unpacked *n = array + idx;
1262                 int j;
1263
1264                 if (!entry->preferred_base)
1265                         processed++;
1266
1267                 if (progress) {
1268                         unsigned percent = processed * 100 / nr_result;
1269                         if (percent != last_percent || progress_update) {
1270                                 fprintf(stderr, "%4u%% (%u/%u) done\r",
1271                                         percent, processed, nr_result);
1272                                 progress_update = 0;
1273                                 last_percent = percent;
1274                         }
1275                 }
1276
1277                 if (entry->delta)
1278                         /* This happens if we decided to reuse existing
1279                          * delta from a pack.  "!no_reuse_delta &&" is implied.
1280                          */
1281                         continue;
1282
1283                 if (entry->size < 50)
1284                         continue;
1285                 free_delta_index(n->index);
1286                 n->index = NULL;
1287                 free(n->data);
1288                 n->data = NULL;
1289                 n->entry = entry;
1290
1291                 j = window;
1292                 while (--j > 0) {
1293                         unsigned int other_idx = idx + j;
1294                         struct unpacked *m;
1295                         if (other_idx >= window)
1296                                 other_idx -= window;
1297                         m = array + other_idx;
1298                         if (!m->entry)
1299                                 break;
1300                         if (try_delta(n, m, depth) < 0)
1301                                 break;
1302                 }
1303                 /* if we made n a delta, and if n is already at max
1304                  * depth, leaving it in the window is pointless.  we
1305                  * should evict it first.
1306                  */
1307                 if (entry->delta && depth <= entry->depth)
1308                         continue;
1309
1310                 idx++;
1311                 if (idx >= window)
1312                         idx = 0;
1313         }
1314
1315         if (progress)
1316                 fputc('\n', stderr);
1317
1318         for (i = 0; i < window; ++i) {
1319                 free_delta_index(array[i].index);
1320                 free(array[i].data);
1321         }
1322         free(array);
1323 }
1324
1325 static void prepare_pack(int window, int depth)
1326 {
1327         get_object_details();
1328         sorted_by_type = create_sorted_list(type_size_sort);
1329         if (window && depth)
1330                 find_deltas(sorted_by_type, window+1, depth);
1331 }
1332
1333 static int reuse_cached_pack(unsigned char *sha1)
1334 {
1335         static const char cache[] = "pack-cache/pack-%s.%s";
1336         char *cached_pack, *cached_idx;
1337         int ifd, ofd, ifd_ix = -1;
1338
1339         cached_pack = git_path(cache, sha1_to_hex(sha1), "pack");
1340         ifd = open(cached_pack, O_RDONLY);
1341         if (ifd < 0)
1342                 return 0;
1343
1344         if (!pack_to_stdout) {
1345                 cached_idx = git_path(cache, sha1_to_hex(sha1), "idx");
1346                 ifd_ix = open(cached_idx, O_RDONLY);
1347                 if (ifd_ix < 0) {
1348                         close(ifd);
1349                         return 0;
1350                 }
1351         }
1352
1353         if (progress)
1354                 fprintf(stderr, "Reusing %d objects pack %s\n", nr_objects,
1355                         sha1_to_hex(sha1));
1356
1357         if (pack_to_stdout) {
1358                 if (copy_fd(ifd, 1))
1359                         exit(1);
1360                 close(ifd);
1361         }
1362         else {
1363                 char name[PATH_MAX];
1364                 snprintf(name, sizeof(name),
1365                          "%s-%s.%s", base_name, sha1_to_hex(sha1), "pack");
1366                 ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
1367                 if (ofd < 0)
1368                         die("unable to open %s (%s)", name, strerror(errno));
1369                 if (copy_fd(ifd, ofd))
1370                         exit(1);
1371                 close(ifd);
1372
1373                 snprintf(name, sizeof(name),
1374                          "%s-%s.%s", base_name, sha1_to_hex(sha1), "idx");
1375                 ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
1376                 if (ofd < 0)
1377                         die("unable to open %s (%s)", name, strerror(errno));
1378                 if (copy_fd(ifd_ix, ofd))
1379                         exit(1);
1380                 close(ifd_ix);
1381                 puts(sha1_to_hex(sha1));
1382         }
1383
1384         return 1;
1385 }
1386
1387 static void setup_progress_signal(void)
1388 {
1389         struct sigaction sa;
1390         struct itimerval v;
1391
1392         memset(&sa, 0, sizeof(sa));
1393         sa.sa_handler = progress_interval;
1394         sigemptyset(&sa.sa_mask);
1395         sa.sa_flags = SA_RESTART;
1396         sigaction(SIGALRM, &sa, NULL);
1397
1398         v.it_interval.tv_sec = 1;
1399         v.it_interval.tv_usec = 0;
1400         v.it_value = v.it_interval;
1401         setitimer(ITIMER_REAL, &v, NULL);
1402 }
1403
1404 static int git_pack_config(const char *k, const char *v)
1405 {
1406         if(!strcmp(k, "pack.window")) {
1407                 window = git_config_int(k, v);
1408                 return 0;
1409         }
1410         return git_default_config(k, v);
1411 }
1412
1413 static void read_object_list_from_stdin(void)
1414 {
1415         char line[40 + 1 + PATH_MAX + 2];
1416         unsigned char sha1[20];
1417         unsigned hash;
1418
1419         for (;;) {
1420                 if (!fgets(line, sizeof(line), stdin)) {
1421                         if (feof(stdin))
1422                                 break;
1423                         if (!ferror(stdin))
1424                                 die("fgets returned NULL, not EOF, not error!");
1425                         if (errno != EINTR)
1426                                 die("fgets: %s", strerror(errno));
1427                         clearerr(stdin);
1428                         continue;
1429                 }
1430                 if (line[0] == '-') {
1431                         if (get_sha1_hex(line+1, sha1))
1432                                 die("expected edge sha1, got garbage:\n %s",
1433                                     line);
1434                         add_preferred_base(sha1);
1435                         continue;
1436                 }
1437                 if (get_sha1_hex(line, sha1))
1438                         die("expected sha1, got garbage:\n %s", line);
1439
1440                 hash = name_hash(line+41);
1441                 add_preferred_base_object(line+41, hash);
1442                 add_object_entry(sha1, hash, 0);
1443         }
1444 }
1445
1446 static void show_commit(struct commit *commit)
1447 {
1448         unsigned hash = name_hash("");
1449         add_preferred_base_object("", hash);
1450         add_object_entry(commit->object.sha1, hash, 0);
1451 }
1452
1453 static void show_object(struct object_array_entry *p)
1454 {
1455         unsigned hash = name_hash(p->name);
1456         add_preferred_base_object(p->name, hash);
1457         add_object_entry(p->item->sha1, hash, 0);
1458 }
1459
1460 static void show_edge(struct commit *commit)
1461 {
1462         add_preferred_base(commit->object.sha1);
1463 }
1464
1465 static void get_object_list(int ac, const char **av)
1466 {
1467         struct rev_info revs;
1468         char line[1000];
1469         int flags = 0;
1470
1471         init_revisions(&revs, NULL);
1472         save_commit_buffer = 0;
1473         track_object_refs = 0;
1474         setup_revisions(ac, av, &revs, NULL);
1475
1476         while (fgets(line, sizeof(line), stdin) != NULL) {
1477                 int len = strlen(line);
1478                 if (line[len - 1] == '\n')
1479                         line[--len] = 0;
1480                 if (!len)
1481                         break;
1482                 if (*line == '-') {
1483                         if (!strcmp(line, "--not")) {
1484                                 flags ^= UNINTERESTING;
1485                                 continue;
1486                         }
1487                         die("not a rev '%s'", line);
1488                 }
1489                 if (handle_revision_arg(line, &revs, flags, 1))
1490                         die("bad revision '%s'", line);
1491         }
1492
1493         prepare_revision_walk(&revs);
1494         mark_edges_uninteresting(revs.commits, &revs, show_edge);
1495         traverse_commit_list(&revs, show_commit, show_object);
1496 }
1497
1498 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
1499 {
1500         SHA_CTX ctx;
1501         int depth = 10;
1502         struct object_entry **list;
1503         int use_internal_rev_list = 0;
1504         int thin = 0;
1505         int i;
1506         const char *rp_av[64];
1507         int rp_ac;
1508
1509         rp_av[0] = "pack-objects";
1510         rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
1511         rp_ac = 2;
1512
1513         git_config(git_pack_config);
1514
1515         progress = isatty(2);
1516         for (i = 1; i < argc; i++) {
1517                 const char *arg = argv[i];
1518
1519                 if (*arg != '-')
1520                         break;
1521
1522                 if (!strcmp("--non-empty", arg)) {
1523                         non_empty = 1;
1524                         continue;
1525                 }
1526                 if (!strcmp("--local", arg)) {
1527                         local = 1;
1528                         continue;
1529                 }
1530                 if (!strcmp("--incremental", arg)) {
1531                         incremental = 1;
1532                         continue;
1533                 }
1534                 if (!strncmp("--window=", arg, 9)) {
1535                         char *end;
1536                         window = strtoul(arg+9, &end, 0);
1537                         if (!arg[9] || *end)
1538                                 usage(pack_usage);
1539                         continue;
1540                 }
1541                 if (!strncmp("--depth=", arg, 8)) {
1542                         char *end;
1543                         depth = strtoul(arg+8, &end, 0);
1544                         if (!arg[8] || *end)
1545                                 usage(pack_usage);
1546                         continue;
1547                 }
1548                 if (!strcmp("--progress", arg)) {
1549                         progress = 1;
1550                         continue;
1551                 }
1552                 if (!strcmp("--all-progress", arg)) {
1553                         progress = 2;
1554                         continue;
1555                 }
1556                 if (!strcmp("-q", arg)) {
1557                         progress = 0;
1558                         continue;
1559                 }
1560                 if (!strcmp("--no-reuse-delta", arg)) {
1561                         no_reuse_delta = 1;
1562                         continue;
1563                 }
1564                 if (!strcmp("--delta-base-offset", arg)) {
1565                         allow_ofs_delta = 1;
1566                         continue;
1567                 }
1568                 if (!strcmp("--stdout", arg)) {
1569                         pack_to_stdout = 1;
1570                         continue;
1571                 }
1572                 if (!strcmp("--revs", arg)) {
1573                         use_internal_rev_list = 1;
1574                         continue;
1575                 }
1576                 if (!strcmp("--unpacked", arg) ||
1577                     !strncmp("--unpacked=", arg, 11) ||
1578                     !strcmp("--all", arg)) {
1579                         use_internal_rev_list = 1;
1580                         if (ARRAY_SIZE(rp_av) - 1 <= rp_ac)
1581                                 die("too many internal rev-list options");
1582                         rp_av[rp_ac++] = arg;
1583                         continue;
1584                 }
1585                 if (!strcmp("--thin", arg)) {
1586                         use_internal_rev_list = 1;
1587                         thin = 1;
1588                         rp_av[1] = "--objects-edge";
1589                         continue;
1590                 }
1591                 usage(pack_usage);
1592         }
1593
1594         /* Traditionally "pack-objects [options] base extra" failed;
1595          * we would however want to take refs parameter that would
1596          * have been given to upstream rev-list ourselves, which means
1597          * we somehow want to say what the base name is.  So the
1598          * syntax would be:
1599          *
1600          * pack-objects [options] base <refs...>
1601          *
1602          * in other words, we would treat the first non-option as the
1603          * base_name and send everything else to the internal revision
1604          * walker.
1605          */
1606
1607         if (!pack_to_stdout)
1608                 base_name = argv[i++];
1609
1610         if (pack_to_stdout != !base_name)
1611                 usage(pack_usage);
1612
1613         if (!pack_to_stdout && thin)
1614                 die("--thin cannot be used to build an indexable pack.");
1615
1616         prepare_packed_git();
1617
1618         if (progress) {
1619                 fprintf(stderr, "Generating pack...\n");
1620                 setup_progress_signal();
1621         }
1622
1623         if (!use_internal_rev_list)
1624                 read_object_list_from_stdin();
1625         else {
1626                 rp_av[rp_ac] = NULL;
1627                 get_object_list(rp_ac, rp_av);
1628         }
1629
1630         if (progress)
1631                 fprintf(stderr, "Done counting %d objects.\n", nr_objects);
1632         sorted_by_sha = create_final_object_list();
1633         if (non_empty && !nr_result)
1634                 return 0;
1635
1636         SHA1_Init(&ctx);
1637         list = sorted_by_sha;
1638         for (i = 0; i < nr_result; i++) {
1639                 struct object_entry *entry = *list++;
1640                 SHA1_Update(&ctx, entry->sha1, 20);
1641         }
1642         SHA1_Final(object_list_sha1, &ctx);
1643         if (progress && (nr_objects != nr_result))
1644                 fprintf(stderr, "Result has %d objects.\n", nr_result);
1645
1646         if (reuse_cached_pack(object_list_sha1))
1647                 ;
1648         else {
1649                 if (nr_result)
1650                         prepare_pack(window, depth);
1651                 if (progress == 1 && pack_to_stdout) {
1652                         /* the other end usually displays progress itself */
1653                         struct itimerval v = {{0,},};
1654                         setitimer(ITIMER_REAL, &v, NULL);
1655                         signal(SIGALRM, SIG_IGN );
1656                         progress_update = 0;
1657                 }
1658                 write_pack_file();
1659                 if (!pack_to_stdout) {
1660                         write_index_file();
1661                         puts(sha1_to_hex(object_list_sha1));
1662                 }
1663         }
1664         if (progress)
1665                 fprintf(stderr, "Total %d (delta %d), reused %d (delta %d)\n",
1666                         written, written_delta, reused, reused_delta);
1667         return 0;
1668 }