pack-objects: avoid delta chains that are too long.
[git/git.git] / pack-objects.c
CommitLineData
c323ac7d
LT
1#include "cache.h"
2#include "object.h"
3#include "delta.h"
a733cb60 4#include "pack.h"
c38138cd 5#include "csum-file.h"
21fcd1bd 6#include <sys/time.h>
c323ac7d 7
ca5381d4 8static const char pack_usage[] = "git-pack-objects [-q] [--no-reuse-delta] [--non-empty] [--local] [--incremental] [--window=N] [--depth=N] {--stdout | base-name} < object-list";
c323ac7d 9
c323ac7d
LT
10struct object_entry {
11 unsigned char sha1[20];
a49dd05f 12 unsigned long size; /* uncompressed size */
e4c9327a
JH
13 unsigned long offset; /* offset into the final pack file;
14 * nonzero if already written.
15 */
a49dd05f 16 unsigned int depth; /* delta depth */
e4c9327a 17 unsigned int delta_limit; /* base adjustment for in-pack delta */
a49dd05f 18 unsigned int hash; /* name hint hash */
a733cb60 19 enum object_type type;
ca5381d4 20 enum object_type in_pack_type; /* could be delta */
a49dd05f
JH
21 unsigned long delta_size; /* delta data size (uncompressed) */
22 struct object_entry *delta; /* delta base object */
23 struct packed_git *in_pack; /* already in pack */
a49dd05f 24 unsigned int in_pack_offset;
e4c9327a
JH
25 struct object_entry *delta_child; /* delitified objects who bases me */
26 struct object_entry *delta_sibling; /* other deltified objects who
27 * uses the same base as me
28 */
c323ac7d
LT
29};
30
a49dd05f
JH
31/*
32 * Objects we are going to pack are colected in objects array (dynamically
33 * expanded). nr_objects & nr_alloc controls this array. They are stored
34 * in the order we see -- typically rev-list --objects order that gives us
35 * nice "minimum seek" order.
36 *
37 * sorted-by-sha ans sorted-by-type are arrays of pointers that point at
38 * elements in the objects array. The former is used to build the pack
39 * index (lists object names in the ascending order to help offset lookup),
40 * and the latter is used to group similar things together by try_delta()
41 * heuristics.
42 */
43
5f3de58f 44static unsigned char object_list_sha1[20];
1c4a2912 45static int non_empty = 0;
ca5381d4 46static int no_reuse_delta = 0;
64560374 47static int local = 0;
eb019375 48static int incremental = 0;
c323ac7d
LT
49static struct object_entry **sorted_by_sha, **sorted_by_type;
50static struct object_entry *objects = NULL;
51static int nr_objects = 0, nr_alloc = 0;
c323ac7d 52static const char *base_name;
e1808845 53static unsigned char pack_file_sha1[20];
024701f1 54static int progress = 1;
c323ac7d 55
a49dd05f
JH
56/*
57 * The object names in objects array are hashed with this hashtable,
58 * to help looking up the entry by object name. Binary search from
59 * sorted_by_sha is also possible but this was easier to code and faster.
60 * This hashtable is built after all the objects are seen.
61 */
62static int *object_ix = NULL;
63static int object_ix_hashsz = 0;
64
65/*
66 * Pack index for existing packs give us easy access to the offsets into
67 * corresponding pack file where each object's data starts, but the entries
68 * do not store the size of the compressed representation (uncompressed
69 * size is easily available by examining the pack entry header). We build
70 * a hashtable of existing packs (pack_revindex), and keep reverse index
71 * here -- pack index file is sorted by object name mapping to offset; this
72 * pack_revindex[].revindex array is an ordered list of offsets, so if you
73 * know the offset of an object, next offset is where its packed
74 * representation ends.
75 */
76struct pack_revindex {
77 struct packed_git *p;
78 unsigned long *revindex;
79} *pack_revindex = NULL;
80static int pack_revindex_hashsz = 0;
81
82/*
83 * stats
84 */
85static int written = 0;
ca5381d4 86static int written_delta = 0;
a49dd05f 87static int reused = 0;
ca5381d4 88static int reused_delta = 0;
a49dd05f
JH
89
90static int pack_revindex_ix(struct packed_git *p)
91{
92 unsigned int ui = (unsigned int) p;
93 int i;
94
95 ui = ui ^ (ui >> 16); /* defeat structure alignment */
96 i = (int)(ui % pack_revindex_hashsz);
97 while (pack_revindex[i].p) {
98 if (pack_revindex[i].p == p)
99 return i;
100 if (++i == pack_revindex_hashsz)
101 i = 0;
102 }
103 return -1 - i;
104}
105
106static void prepare_pack_ix(void)
107{
108 int num;
109 struct packed_git *p;
110 for (num = 0, p = packed_git; p; p = p->next)
111 num++;
112 if (!num)
113 return;
114 pack_revindex_hashsz = num * 11;
115 pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
116 for (p = packed_git; p; p = p->next) {
117 num = pack_revindex_ix(p);
118 num = - 1 - num;
119 pack_revindex[num].p = p;
120 }
121 /* revindex elements are lazily initialized */
122}
123
124static int cmp_offset(const void *a_, const void *b_)
125{
126 unsigned long a = *(unsigned long *) a_;
127 unsigned long b = *(unsigned long *) b_;
128 if (a < b)
129 return -1;
130 else if (a == b)
131 return 0;
132 else
133 return 1;
134}
135
136/*
137 * Ordered list of offsets of objects in the pack.
138 */
139static void prepare_pack_revindex(struct pack_revindex *rix)
140{
141 struct packed_git *p = rix->p;
142 int num_ent = num_packed_objects(p);
143 int i;
144 void *index = p->index_base + 256;
145
146 rix->revindex = xmalloc(sizeof(unsigned long) * (num_ent + 1));
147 for (i = 0; i < num_ent; i++) {
148 long hl = *((long *)(index + 24 * i));
149 rix->revindex[i] = ntohl(hl);
150 }
151 /* This knows the pack format -- the 20-byte trailer
152 * follows immediately after the last object data.
153 */
154 rix->revindex[num_ent] = p->pack_size - 20;
155 qsort(rix->revindex, num_ent, sizeof(unsigned long), cmp_offset);
156}
157
158static unsigned long find_packed_object_size(struct packed_git *p,
159 unsigned long ofs)
160{
161 int num;
162 int lo, hi;
163 struct pack_revindex *rix;
164 unsigned long *revindex;
165 num = pack_revindex_ix(p);
166 if (num < 0)
167 die("internal error: pack revindex uninitialized");
168 rix = &pack_revindex[num];
169 if (!rix->revindex)
170 prepare_pack_revindex(rix);
171 revindex = rix->revindex;
172 lo = 0;
173 hi = num_packed_objects(p) + 1;
174 do {
175 int mi = (lo + hi) / 2;
176 if (revindex[mi] == ofs) {
177 return revindex[mi+1] - ofs;
178 }
179 else if (ofs < revindex[mi])
180 hi = mi;
181 else
182 lo = mi + 1;
183 } while (lo < hi);
184 die("internal error: pack revindex corrupt");
185}
186
c323ac7d
LT
187static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
188{
189 unsigned long othersize, delta_size;
190 char type[10];
191 void *otherbuf = read_sha1_file(entry->delta->sha1, type, &othersize);
192 void *delta_buf;
193
194 if (!otherbuf)
195 die("unable to read %s", sha1_to_hex(entry->delta->sha1));
8ee378a0 196 delta_buf = diff_delta(otherbuf, othersize,
dcde55bc 197 buf, size, &delta_size, 0);
75c42d8c 198 if (!delta_buf || delta_size != entry->delta_size)
c323ac7d
LT
199 die("delta size changed");
200 free(buf);
201 free(otherbuf);
202 return delta_buf;
203}
204
a733cb60
LT
205/*
206 * The per-object header is a pretty dense thing, which is
207 * - first byte: low four bits are "size", then three bits of "type",
208 * and the high bit is "size continues".
209 * - each byte afterwards: low seven bits are size continuation,
210 * with the high bit being "size continues"
211 */
212static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
213{
01247d87 214 int n = 1;
a733cb60
LT
215 unsigned char c;
216
217 if (type < OBJ_COMMIT || type > OBJ_DELTA)
218 die("bad type %d", type);
219
01247d87
LT
220 c = (type << 4) | (size & 15);
221 size >>= 4;
222 while (size) {
a733cb60 223 *hdr++ = c | 0x80;
01247d87
LT
224 c = size & 0x7f;
225 size >>= 7;
226 n++;
a733cb60
LT
227 }
228 *hdr = c;
229 return n;
230}
231
c38138cd 232static unsigned long write_object(struct sha1file *f, struct object_entry *entry)
c323ac7d
LT
233{
234 unsigned long size;
235 char type[10];
a49dd05f 236 void *buf;
a733cb60 237 unsigned char header[10];
c323ac7d 238 unsigned hdrlen, datalen;
a733cb60 239 enum object_type obj_type;
ca5381d4 240 int to_reuse = 0;
c323ac7d 241
a733cb60 242 obj_type = entry->type;
ca5381d4
JH
243 if (! entry->in_pack)
244 to_reuse = 0; /* can't reuse what we don't have */
245 else if (obj_type == OBJ_DELTA)
246 to_reuse = 1; /* check_object() decided it for us */
247 else if (obj_type != entry->in_pack_type)
248 to_reuse = 0; /* pack has delta which is unusable */
249 else if (entry->delta)
250 to_reuse = 0; /* we want to pack afresh */
251 else
252 to_reuse = 1; /* we have it in-pack undeltified,
253 * and we do not need to deltify it.
254 */
255
256 if (! to_reuse) {
a49dd05f
JH
257 buf = read_sha1_file(entry->sha1, type, &size);
258 if (!buf)
259 die("unable to read %s", sha1_to_hex(entry->sha1));
260 if (size != entry->size)
261 die("object %s size inconsistency (%lu vs %lu)",
262 sha1_to_hex(entry->sha1), size, entry->size);
263 if (entry->delta) {
264 buf = delta_against(buf, size, entry);
265 size = entry->delta_size;
266 obj_type = OBJ_DELTA;
267 }
268 /*
269 * The object header is a byte of 'type' followed by zero or
270 * more bytes of length. For deltas, the 20 bytes of delta
271 * sha1 follows that.
272 */
273 hdrlen = encode_header(obj_type, size, header);
274 sha1write(f, header, hdrlen);
275
276 if (entry->delta) {
277 sha1write(f, entry->delta, 20);
278 hdrlen += 20;
279 }
280 datalen = sha1write_compressed(f, buf, size);
281 free(buf);
c323ac7d 282 }
a49dd05f
JH
283 else {
284 struct packed_git *p = entry->in_pack;
285 use_packed_git(p);
286
287 datalen = find_packed_object_size(p, entry->in_pack_offset);
288 buf = p->pack_base + entry->in_pack_offset;
289 sha1write(f, buf, datalen);
290 unuse_packed_git(p);
291 hdrlen = 0; /* not really */
ca5381d4
JH
292 if (obj_type == OBJ_DELTA)
293 reused_delta++;
a49dd05f 294 reused++;
a733cb60 295 }
ca5381d4
JH
296 if (obj_type == OBJ_DELTA)
297 written_delta++;
a49dd05f 298 written++;
c323ac7d
LT
299 return hdrlen + datalen;
300}
301
9d5ab962
JH
302static unsigned long write_one(struct sha1file *f,
303 struct object_entry *e,
304 unsigned long offset)
305{
306 if (e->offset)
307 /* offset starts from header size and cannot be zero
308 * if it is written already.
309 */
310 return offset;
311 e->offset = offset;
312 offset += write_object(f, e);
82f9d58a 313 /* if we are deltified, write out its base object. */
9d5ab962
JH
314 if (e->delta)
315 offset = write_one(f, e->delta, offset);
316 return offset;
317}
318
c323ac7d
LT
319static void write_pack_file(void)
320{
321 int i;
d22b9290 322 struct sha1file *f;
a733cb60 323 unsigned long offset;
a733cb60 324 struct pack_header hdr;
c323ac7d 325
d22b9290
LT
326 if (!base_name)
327 f = sha1fd(1, "<stdout>");
328 else
5f3de58f 329 f = sha1create("%s-%s.%s", base_name, sha1_to_hex(object_list_sha1), "pack");
a733cb60 330 hdr.hdr_signature = htonl(PACK_SIGNATURE);
01247d87 331 hdr.hdr_version = htonl(PACK_VERSION);
a733cb60
LT
332 hdr.hdr_entries = htonl(nr_objects);
333 sha1write(f, &hdr, sizeof(hdr));
334 offset = sizeof(hdr);
9d5ab962
JH
335 for (i = 0; i < nr_objects; i++)
336 offset = write_one(f, objects + i, offset);
337
e1808845 338 sha1close(f, pack_file_sha1, 1);
c323ac7d
LT
339}
340
341static void write_index_file(void)
342{
343 int i;
5f3de58f 344 struct sha1file *f = sha1create("%s-%s.%s", base_name, sha1_to_hex(object_list_sha1), "idx");
c323ac7d
LT
345 struct object_entry **list = sorted_by_sha;
346 struct object_entry **last = list + nr_objects;
347 unsigned int array[256];
348
349 /*
350 * Write the first-level table (the list is sorted,
351 * but we use a 256-entry lookup to be able to avoid
e1808845 352 * having to do eight extra binary search iterations).
c323ac7d
LT
353 */
354 for (i = 0; i < 256; i++) {
355 struct object_entry **next = list;
356 while (next < last) {
357 struct object_entry *entry = *next;
358 if (entry->sha1[0] != i)
359 break;
360 next++;
361 }
362 array[i] = htonl(next - sorted_by_sha);
363 list = next;
364 }
c38138cd 365 sha1write(f, array, 256 * sizeof(int));
c323ac7d
LT
366
367 /*
368 * Write the actual SHA1 entries..
369 */
370 list = sorted_by_sha;
49397104 371 for (i = 0; i < nr_objects; i++) {
c323ac7d
LT
372 struct object_entry *entry = *list++;
373 unsigned int offset = htonl(entry->offset);
c38138cd
LT
374 sha1write(f, &offset, 4);
375 sha1write(f, entry->sha1, 20);
c323ac7d 376 }
e1808845
LT
377 sha1write(f, pack_file_sha1, 20);
378 sha1close(f, NULL, 1);
c323ac7d
LT
379}
380
5f3de58f 381static int add_object_entry(unsigned char *sha1, unsigned int hash)
c323ac7d
LT
382{
383 unsigned int idx = nr_objects;
384 struct object_entry *entry;
a49dd05f 385 struct packed_git *p;
ca5381d4
JH
386 unsigned int found_offset = 0;
387 struct packed_git *found_pack = NULL;
a49dd05f 388
a49dd05f
JH
389 for (p = packed_git; p; p = p->next) {
390 struct pack_entry e;
391 if (find_pack_entry_one(sha1, &e, p)) {
392 if (incremental)
393 return 0;
394 if (local && !p->pack_local)
395 return 0;
396 if (!found_pack) {
397 found_offset = e.offset;
398 found_pack = e.p;
64560374
LT
399 }
400 }
401 }
eb019375 402
c323ac7d
LT
403 if (idx >= nr_alloc) {
404 unsigned int needed = (idx + 1024) * 3 / 2;
405 objects = xrealloc(objects, needed * sizeof(*entry));
406 nr_alloc = needed;
407 }
408 entry = objects + idx;
409 memset(entry, 0, sizeof(*entry));
410 memcpy(entry->sha1, sha1, 20);
27225f2e 411 entry->hash = hash;
a49dd05f
JH
412 if (found_pack) {
413 entry->in_pack = found_pack;
414 entry->in_pack_offset = found_offset;
415 }
c323ac7d 416 nr_objects = idx+1;
5f3de58f 417 return 1;
c323ac7d
LT
418}
419
a49dd05f
JH
420static int locate_object_entry_hash(unsigned char *sha1)
421{
422 int i;
423 unsigned int ui;
424 memcpy(&ui, sha1, sizeof(unsigned int));
425 i = ui % object_ix_hashsz;
426 while (0 < object_ix[i]) {
427 if (!memcmp(sha1, objects[object_ix[i]-1].sha1, 20))
428 return i;
429 if (++i == object_ix_hashsz)
430 i = 0;
431 }
432 return -1 - i;
433}
434
435static struct object_entry *locate_object_entry(unsigned char *sha1)
436{
437 int i = locate_object_entry_hash(sha1);
438 if (0 <= i)
439 return &objects[object_ix[i]-1];
440 return NULL;
441}
442
c323ac7d
LT
443static void check_object(struct object_entry *entry)
444{
36e4d74a
JH
445 char type[20];
446
a49dd05f 447 if (entry->in_pack) {
ca5381d4
JH
448 unsigned char base[20];
449 unsigned long size;
450 struct object_entry *base_entry;
451
452 /* We want in_pack_type even if we do not reuse delta.
453 * There is no point not reusing non-delta representations.
454 */
455 check_reuse_pack_delta(entry->in_pack,
456 entry->in_pack_offset,
457 base, &size,
458 &entry->in_pack_type);
459
a49dd05f
JH
460 /* Check if it is delta, and the base is also an object
461 * we are going to pack. If so we will reuse the existing
462 * delta.
463 */
ca5381d4
JH
464 if (!no_reuse_delta &&
465 entry->in_pack_type == OBJ_DELTA &&
a49dd05f 466 (base_entry = locate_object_entry(base))) {
ca5381d4
JH
467
468 /* Depth value does not matter - find_deltas()
469 * will never consider reused delta as the
470 * base object to deltify other objects
471 * against, in order to avoid circular deltas.
a49dd05f 472 */
ca5381d4
JH
473
474 /* uncompressed size of the delta data */
a49dd05f
JH
475 entry->size = entry->delta_size = size;
476 entry->delta = base_entry;
477 entry->type = OBJ_DELTA;
ca5381d4 478
e4c9327a
JH
479 entry->delta_sibling = base_entry->delta_child;
480 base_entry->delta_child = entry;
ca5381d4 481
a49dd05f
JH
482 return;
483 }
484 /* Otherwise we would do the usual */
36e4d74a 485 }
a49dd05f
JH
486
487 if (sha1_object_info(entry->sha1, type, &entry->size))
36e4d74a
JH
488 die("unable to get type of object %s",
489 sha1_to_hex(entry->sha1));
a49dd05f
JH
490
491 if (!strcmp(type, "commit")) {
492 entry->type = OBJ_COMMIT;
493 } else if (!strcmp(type, "tree")) {
494 entry->type = OBJ_TREE;
495 } else if (!strcmp(type, "blob")) {
496 entry->type = OBJ_BLOB;
497 } else if (!strcmp(type, "tag")) {
498 entry->type = OBJ_TAG;
499 } else
500 die("unable to pack object %s of type %s",
501 sha1_to_hex(entry->sha1), type);
502}
503
504static void hash_objects(void)
505{
506 int i;
507 struct object_entry *oe;
508
509 object_ix_hashsz = nr_objects * 2;
510 object_ix = xcalloc(sizeof(int), object_ix_hashsz);
511 for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
512 int ix = locate_object_entry_hash(oe->sha1);
513 if (0 <= ix) {
514 error("the same object '%s' added twice",
515 sha1_to_hex(oe->sha1));
516 continue;
517 }
518 ix = -1 - ix;
519 object_ix[ix] = i + 1;
520 }
c323ac7d
LT
521}
522
e4c9327a
JH
523static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
524{
525 struct object_entry *child = me->delta_child;
526 unsigned int m = n;
527 while (child) {
528 unsigned int c = check_delta_limit(child, n + 1);
529 if (m < c)
530 m = c;
531 child = child->delta_sibling;
532 }
533 return m;
534}
535
c323ac7d
LT
536static void get_object_details(void)
537{
538 int i;
e4c9327a 539 struct object_entry *entry;
c323ac7d 540
a49dd05f
JH
541 hash_objects();
542 prepare_pack_ix();
e4c9327a
JH
543 for (i = 0, entry = objects; i < nr_objects; i++, entry++)
544 check_object(entry);
545 for (i = 0, entry = objects; i < nr_objects; i++, entry++)
546 if (!entry->delta && entry->delta_child)
547 entry->delta_limit =
548 check_delta_limit(entry, 1);
c323ac7d
LT
549}
550
551typedef int (*entry_sort_t)(const struct object_entry *, const struct object_entry *);
552
553static entry_sort_t current_sort;
554
555static int sort_comparator(const void *_a, const void *_b)
556{
557 struct object_entry *a = *(struct object_entry **)_a;
558 struct object_entry *b = *(struct object_entry **)_b;
559 return current_sort(a,b);
560}
561
562static struct object_entry **create_sorted_list(entry_sort_t sort)
563{
564 struct object_entry **list = xmalloc(nr_objects * sizeof(struct object_entry *));
565 int i;
566
567 for (i = 0; i < nr_objects; i++)
568 list[i] = objects + i;
569 current_sort = sort;
570 qsort(list, nr_objects, sizeof(struct object_entry *), sort_comparator);
571 return list;
572}
573
574static int sha1_sort(const struct object_entry *a, const struct object_entry *b)
575{
576 return memcmp(a->sha1, b->sha1, 20);
577}
578
579static int type_size_sort(const struct object_entry *a, const struct object_entry *b)
580{
581 if (a->type < b->type)
582 return -1;
583 if (a->type > b->type)
584 return 1;
27225f2e
LT
585 if (a->hash < b->hash)
586 return -1;
587 if (a->hash > b->hash)
588 return 1;
c323ac7d
LT
589 if (a->size < b->size)
590 return -1;
591 if (a->size > b->size)
592 return 1;
593 return a < b ? -1 : (a > b);
594}
595
596struct unpacked {
597 struct object_entry *entry;
598 void *data;
599};
600
601/*
521a4f4c
LT
602 * We search for deltas _backwards_ in a list sorted by type and
603 * by size, so that we see progressively smaller and smaller files.
604 * That's because we prefer deltas to be from the bigger file
605 * to the smaller - deletes are potentially cheaper, but perhaps
606 * more importantly, the bigger file is likely the more recent
607 * one.
c323ac7d 608 */
d116a45a 609static int try_delta(struct unpacked *cur, struct unpacked *old, unsigned max_depth)
c323ac7d
LT
610{
611 struct object_entry *cur_entry = cur->entry;
612 struct object_entry *old_entry = old->entry;
521a4f4c 613 unsigned long size, oldsize, delta_size, sizediff;
75c42d8c 614 long max_size;
c323ac7d
LT
615 void *delta_buf;
616
617 /* Don't bother doing diffs between different types */
618 if (cur_entry->type != old_entry->type)
619 return -1;
620
ca5381d4
JH
621 /* If the current object is at edge, take the depth the objects
622 * that depend on the current object into account -- otherwise
623 * they would become too deep.
624 */
e4c9327a
JH
625 if (cur_entry->delta_child) {
626 if (max_depth <= cur_entry->delta_limit)
627 return 0;
628 max_depth -= cur_entry->delta_limit;
629 }
ca5381d4 630
c323ac7d 631 size = cur_entry->size;
75c42d8c
LT
632 if (size < 50)
633 return -1;
c323ac7d 634 oldsize = old_entry->size;
521a4f4c
LT
635 sizediff = oldsize > size ? oldsize - size : size - oldsize;
636 if (sizediff > size / 8)
c323ac7d 637 return -1;
d116a45a
LT
638 if (old_entry->depth >= max_depth)
639 return 0;
c323ac7d
LT
640
641 /*
642 * NOTE!
643 *
644 * We always delta from the bigger to the smaller, since that's
645 * more space-efficient (deletes don't have to say _what_ they
646 * delete).
647 */
75c42d8c
LT
648 max_size = size / 2 - 20;
649 if (cur_entry->delta)
650 max_size = cur_entry->delta_size-1;
27225f2e
LT
651 if (sizediff >= max_size)
652 return -1;
8ee378a0
JH
653 delta_buf = diff_delta(old->data, oldsize,
654 cur->data, size, &delta_size, max_size);
c323ac7d 655 if (!delta_buf)
75c42d8c
LT
656 return 0;
657 cur_entry->delta = old_entry;
658 cur_entry->delta_size = delta_size;
d116a45a 659 cur_entry->depth = old_entry->depth + 1;
c323ac7d 660 free(delta_buf);
eb41ab11 661 return 0;
c323ac7d
LT
662}
663
d116a45a 664static void find_deltas(struct object_entry **list, int window, int depth)
c323ac7d 665{
521a4f4c 666 int i, idx;
c323ac7d
LT
667 unsigned int array_size = window * sizeof(struct unpacked);
668 struct unpacked *array = xmalloc(array_size);
21fcd1bd 669 int eye_candy;
c323ac7d
LT
670
671 memset(array, 0, array_size);
521a4f4c
LT
672 i = nr_objects;
673 idx = 0;
21fcd1bd
JH
674 eye_candy = i - (nr_objects / 20);
675
521a4f4c 676 while (--i >= 0) {
c323ac7d
LT
677 struct object_entry *entry = list[i];
678 struct unpacked *n = array + idx;
679 unsigned long size;
680 char type[10];
681 int j;
682
21fcd1bd
JH
683 if (progress && i <= eye_candy) {
684 eye_candy -= nr_objects / 20;
685 fputc('.', stderr);
686 }
a49dd05f
JH
687
688 if (entry->delta)
689 /* This happens if we decided to reuse existing
ca5381d4 690 * delta from a pack. "!no_reuse_delta &&" is implied.
a49dd05f
JH
691 */
692 continue;
693
c323ac7d
LT
694 free(n->data);
695 n->entry = entry;
696 n->data = read_sha1_file(entry->sha1, type, &size);
697 if (size != entry->size)
698 die("object %s inconsistent object length (%lu vs %lu)", sha1_to_hex(entry->sha1), size, entry->size);
ca5381d4 699
78817c15
LT
700 j = window;
701 while (--j > 0) {
702 unsigned int other_idx = idx + j;
c323ac7d 703 struct unpacked *m;
78817c15
LT
704 if (other_idx >= window)
705 other_idx -= window;
c323ac7d
LT
706 m = array + other_idx;
707 if (!m->entry)
708 break;
d116a45a 709 if (try_delta(n, m, depth) < 0)
c323ac7d
LT
710 break;
711 }
521a4f4c
LT
712 idx++;
713 if (idx >= window)
714 idx = 0;
c323ac7d 715 }
adee7bdf
SV
716
717 for (i = 0; i < window; ++i)
718 free(array[i].data);
719 free(array);
c323ac7d
LT
720}
721
f3123c4a
JH
722static void prepare_pack(int window, int depth)
723{
21fcd1bd
JH
724 if (progress)
725 fprintf(stderr, "Packing %d objects", nr_objects);
a49dd05f
JH
726 get_object_details();
727 if (progress)
ca5381d4 728 fputc('.', stderr);
a49dd05f 729
f3123c4a
JH
730 sorted_by_type = create_sorted_list(type_size_sort);
731 if (window && depth)
732 find_deltas(sorted_by_type, window+1, depth);
21fcd1bd
JH
733 if (progress)
734 fputc('\n', stderr);
f3123c4a
JH
735 write_pack_file();
736}
737
738static int reuse_cached_pack(unsigned char *sha1, int pack_to_stdout)
739{
740 static const char cache[] = "pack-cache/pack-%s.%s";
741 char *cached_pack, *cached_idx;
742 int ifd, ofd, ifd_ix = -1;
743
744 cached_pack = git_path(cache, sha1_to_hex(sha1), "pack");
745 ifd = open(cached_pack, O_RDONLY);
746 if (ifd < 0)
747 return 0;
748
749 if (!pack_to_stdout) {
750 cached_idx = git_path(cache, sha1_to_hex(sha1), "idx");
751 ifd_ix = open(cached_idx, O_RDONLY);
752 if (ifd_ix < 0) {
753 close(ifd);
754 return 0;
755 }
756 }
757
ca5381d4
JH
758 if (progress)
759 fprintf(stderr, "Reusing %d objects pack %s\n", nr_objects,
760 sha1_to_hex(sha1));
f3123c4a
JH
761
762 if (pack_to_stdout) {
763 if (copy_fd(ifd, 1))
764 exit(1);
765 close(ifd);
766 }
767 else {
768 char name[PATH_MAX];
769 snprintf(name, sizeof(name),
770 "%s-%s.%s", base_name, sha1_to_hex(sha1), "pack");
771 ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
772 if (ofd < 0)
773 die("unable to open %s (%s)", name, strerror(errno));
774 if (copy_fd(ifd, ofd))
775 exit(1);
776 close(ifd);
777
778 snprintf(name, sizeof(name),
779 "%s-%s.%s", base_name, sha1_to_hex(sha1), "idx");
780 ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
781 if (ofd < 0)
782 die("unable to open %s (%s)", name, strerror(errno));
783 if (copy_fd(ifd_ix, ofd))
784 exit(1);
785 close(ifd_ix);
786 puts(sha1_to_hex(sha1));
787 }
788
789 return 1;
790}
791
c323ac7d
LT
792int main(int argc, char **argv)
793{
5f3de58f 794 SHA_CTX ctx;
27225f2e 795 char line[PATH_MAX + 20];
d22b9290 796 int window = 10, depth = 10, pack_to_stdout = 0;
84c8d8ae 797 struct object_entry **list;
c323ac7d 798 int i;
21fcd1bd
JH
799 struct timeval prev_tv;
800 int eye_candy = 0;
801 int eye_candy_incr = 500;
802
c323ac7d 803
53228a5f
JH
804 setup_git_directory();
805
c323ac7d
LT
806 for (i = 1; i < argc; i++) {
807 const char *arg = argv[i];
808
809 if (*arg == '-') {
1c4a2912
LT
810 if (!strcmp("--non-empty", arg)) {
811 non_empty = 1;
812 continue;
813 }
64560374
LT
814 if (!strcmp("--local", arg)) {
815 local = 1;
816 continue;
817 }
eb019375
LT
818 if (!strcmp("--incremental", arg)) {
819 incremental = 1;
820 continue;
821 }
c323ac7d
LT
822 if (!strncmp("--window=", arg, 9)) {
823 char *end;
f846bbff 824 window = strtoul(arg+9, &end, 0);
c323ac7d
LT
825 if (!arg[9] || *end)
826 usage(pack_usage);
827 continue;
828 }
d116a45a
LT
829 if (!strncmp("--depth=", arg, 8)) {
830 char *end;
831 depth = strtoul(arg+8, &end, 0);
832 if (!arg[8] || *end)
833 usage(pack_usage);
834 continue;
835 }
024701f1
JH
836 if (!strcmp("-q", arg)) {
837 progress = 0;
838 continue;
839 }
ca5381d4
JH
840 if (!strcmp("--no-reuse-delta", arg)) {
841 no_reuse_delta = 1;
842 continue;
843 }
d22b9290
LT
844 if (!strcmp("--stdout", arg)) {
845 pack_to_stdout = 1;
846 continue;
847 }
c323ac7d
LT
848 usage(pack_usage);
849 }
850 if (base_name)
851 usage(pack_usage);
852 base_name = arg;
853 }
854
d22b9290 855 if (pack_to_stdout != !base_name)
c323ac7d
LT
856 usage(pack_usage);
857
64560374 858 prepare_packed_git();
21fcd1bd
JH
859 if (progress) {
860 fprintf(stderr, "Generating pack...\n");
861 gettimeofday(&prev_tv, NULL);
862 }
c323ac7d 863 while (fgets(line, sizeof(line), stdin) != NULL) {
27225f2e
LT
864 unsigned int hash;
865 char *p;
c323ac7d 866 unsigned char sha1[20];
27225f2e 867
21fcd1bd
JH
868 if (progress && (eye_candy <= nr_objects)) {
869 fprintf(stderr, "Counting objects...%d\r", nr_objects);
870 if (eye_candy && (50 <= eye_candy_incr)) {
871 struct timeval tv;
872 int time_diff;
873 gettimeofday(&tv, NULL);
874 time_diff = (tv.tv_sec - prev_tv.tv_sec);
875 time_diff <<= 10;
876 time_diff += (tv.tv_usec - prev_tv.tv_usec);
877 if ((1 << 9) < time_diff)
878 eye_candy_incr += 50;
879 else if (50 < eye_candy_incr)
880 eye_candy_incr -= 50;
881 }
882 eye_candy += eye_candy_incr;
883 }
c323ac7d 884 if (get_sha1_hex(line, sha1))
ef07618f 885 die("expected sha1, got garbage:\n %s", line);
27225f2e
LT
886 hash = 0;
887 p = line+40;
888 while (*p) {
889 unsigned char c = *p++;
890 if (isspace(c))
891 continue;
892 hash = hash * 11 + c;
893 }
84c8d8ae 894 add_object_entry(sha1, hash);
c323ac7d 895 }
21fcd1bd
JH
896 if (progress)
897 fprintf(stderr, "Done counting %d objects.\n", nr_objects);
1c4a2912
LT
898 if (non_empty && !nr_objects)
899 return 0;
c323ac7d
LT
900
901 sorted_by_sha = create_sorted_list(sha1_sort);
84c8d8ae
JH
902 SHA1_Init(&ctx);
903 list = sorted_by_sha;
904 for (i = 0; i < nr_objects; i++) {
905 struct object_entry *entry = *list++;
906 SHA1_Update(&ctx, entry->sha1, 20);
907 }
908 SHA1_Final(object_list_sha1, &ctx);
909
f3123c4a
JH
910 if (reuse_cached_pack(object_list_sha1, pack_to_stdout))
911 ;
912 else {
913 prepare_pack(window, depth);
914 if (!pack_to_stdout) {
915 write_index_file();
916 puts(sha1_to_hex(object_list_sha1));
917 }
5f3de58f 918 }
ca5381d4
JH
919 if (progress)
920 fprintf(stderr, "Total %d, written %d (delta %d), reused %d (delta %d)\n",
921 nr_objects, written, written_delta, reused, reused_delta);
c323ac7d
LT
922 return 0;
923}