Merge branch 'jk/still-interesting' into maint
[git/git.git] / pack-bitmap.c
1 #include "cache.h"
2 #include "commit.h"
3 #include "tag.h"
4 #include "diff.h"
5 #include "revision.h"
6 #include "progress.h"
7 #include "list-objects.h"
8 #include "pack.h"
9 #include "pack-bitmap.h"
10 #include "pack-revindex.h"
11 #include "pack-objects.h"
12
13 /*
14 * An entry on the bitmap index, representing the bitmap for a given
15 * commit.
16 */
17 struct stored_bitmap {
18 unsigned char sha1[20];
19 struct ewah_bitmap *root;
20 struct stored_bitmap *xor;
21 int flags;
22 };
23
24 /*
25 * The currently active bitmap index. By design, repositories only have
26 * a single bitmap index available (the index for the biggest packfile in
27 * the repository), since bitmap indexes need full closure.
28 *
29 * If there is more than one bitmap index available (e.g. because of alternates),
30 * the active bitmap index is the largest one.
31 */
32 static struct bitmap_index {
33 /* Packfile to which this bitmap index belongs to */
34 struct packed_git *pack;
35
36 /* reverse index for the packfile */
37 struct pack_revindex *reverse_index;
38
39 /*
40 * Mark the first `reuse_objects` in the packfile as reused:
41 * they will be sent as-is without using them for repacking
42 * calculations
43 */
44 uint32_t reuse_objects;
45
46 /* mmapped buffer of the whole bitmap index */
47 unsigned char *map;
48 size_t map_size; /* size of the mmaped buffer */
49 size_t map_pos; /* current position when loading the index */
50
51 /*
52 * Type indexes.
53 *
54 * Each bitmap marks which objects in the packfile are of the given
55 * type. This provides type information when yielding the objects from
56 * the packfile during a walk, which allows for better delta bases.
57 */
58 struct ewah_bitmap *commits;
59 struct ewah_bitmap *trees;
60 struct ewah_bitmap *blobs;
61 struct ewah_bitmap *tags;
62
63 /* Map from SHA1 -> `stored_bitmap` for all the bitmapped commits */
64 khash_sha1 *bitmaps;
65
66 /* Number of bitmapped commits */
67 uint32_t entry_count;
68
69 /* Name-hash cache (or NULL if not present). */
70 uint32_t *hashes;
71
72 /*
73 * Extended index.
74 *
75 * When trying to perform bitmap operations with objects that are not
76 * packed in `pack`, these objects are added to this "fake index" and
77 * are assumed to appear at the end of the packfile for all operations
78 */
79 struct eindex {
80 struct object **objects;
81 uint32_t *hashes;
82 uint32_t count, alloc;
83 khash_sha1_pos *positions;
84 } ext_index;
85
86 /* Bitmap result of the last performed walk */
87 struct bitmap *result;
88
89 /* Version of the bitmap index */
90 unsigned int version;
91
92 unsigned loaded : 1;
93
94 } bitmap_git;
95
96 static struct ewah_bitmap *lookup_stored_bitmap(struct stored_bitmap *st)
97 {
98 struct ewah_bitmap *parent;
99 struct ewah_bitmap *composed;
100
101 if (st->xor == NULL)
102 return st->root;
103
104 composed = ewah_pool_new();
105 parent = lookup_stored_bitmap(st->xor);
106 ewah_xor(st->root, parent, composed);
107
108 ewah_pool_free(st->root);
109 st->root = composed;
110 st->xor = NULL;
111
112 return composed;
113 }
114
115 /*
116 * Read a bitmap from the current read position on the mmaped
117 * index, and increase the read position accordingly
118 */
119 static struct ewah_bitmap *read_bitmap_1(struct bitmap_index *index)
120 {
121 struct ewah_bitmap *b = ewah_pool_new();
122
123 int bitmap_size = ewah_read_mmap(b,
124 index->map + index->map_pos,
125 index->map_size - index->map_pos);
126
127 if (bitmap_size < 0) {
128 error("Failed to load bitmap index (corrupted?)");
129 ewah_pool_free(b);
130 return NULL;
131 }
132
133 index->map_pos += bitmap_size;
134 return b;
135 }
136
137 static int load_bitmap_header(struct bitmap_index *index)
138 {
139 struct bitmap_disk_header *header = (void *)index->map;
140
141 if (index->map_size < sizeof(*header) + 20)
142 return error("Corrupted bitmap index (missing header data)");
143
144 if (memcmp(header->magic, BITMAP_IDX_SIGNATURE, sizeof(BITMAP_IDX_SIGNATURE)) != 0)
145 return error("Corrupted bitmap index file (wrong header)");
146
147 index->version = ntohs(header->version);
148 if (index->version != 1)
149 return error("Unsupported version for bitmap index file (%d)", index->version);
150
151 /* Parse known bitmap format options */
152 {
153 uint32_t flags = ntohs(header->options);
154
155 if ((flags & BITMAP_OPT_FULL_DAG) == 0)
156 return error("Unsupported options for bitmap index file "
157 "(Git requires BITMAP_OPT_FULL_DAG)");
158
159 if (flags & BITMAP_OPT_HASH_CACHE) {
160 unsigned char *end = index->map + index->map_size - 20;
161 index->hashes = ((uint32_t *)end) - index->pack->num_objects;
162 }
163 }
164
165 index->entry_count = ntohl(header->entry_count);
166 index->map_pos += sizeof(*header);
167 return 0;
168 }
169
170 static struct stored_bitmap *store_bitmap(struct bitmap_index *index,
171 struct ewah_bitmap *root,
172 const unsigned char *sha1,
173 struct stored_bitmap *xor_with,
174 int flags)
175 {
176 struct stored_bitmap *stored;
177 khiter_t hash_pos;
178 int ret;
179
180 stored = xmalloc(sizeof(struct stored_bitmap));
181 stored->root = root;
182 stored->xor = xor_with;
183 stored->flags = flags;
184 hashcpy(stored->sha1, sha1);
185
186 hash_pos = kh_put_sha1(index->bitmaps, stored->sha1, &ret);
187
188 /* a 0 return code means the insertion succeeded with no changes,
189 * because the SHA1 already existed on the map. this is bad, there
190 * shouldn't be duplicated commits in the index */
191 if (ret == 0) {
192 error("Duplicate entry in bitmap index: %s", sha1_to_hex(sha1));
193 return NULL;
194 }
195
196 kh_value(index->bitmaps, hash_pos) = stored;
197 return stored;
198 }
199
200 static inline uint32_t read_be32(const unsigned char *buffer, size_t *pos)
201 {
202 uint32_t result = get_be32(buffer + *pos);
203 (*pos) += sizeof(result);
204 return result;
205 }
206
207 static inline uint8_t read_u8(const unsigned char *buffer, size_t *pos)
208 {
209 return buffer[(*pos)++];
210 }
211
212 static int load_bitmap_entries_v1(struct bitmap_index *index)
213 {
214 static const size_t MAX_XOR_OFFSET = 160;
215
216 uint32_t i;
217 struct stored_bitmap **recent_bitmaps;
218
219 recent_bitmaps = xcalloc(MAX_XOR_OFFSET, sizeof(struct stored_bitmap));
220
221 for (i = 0; i < index->entry_count; ++i) {
222 int xor_offset, flags;
223 struct ewah_bitmap *bitmap = NULL;
224 struct stored_bitmap *xor_bitmap = NULL;
225 uint32_t commit_idx_pos;
226 const unsigned char *sha1;
227
228 commit_idx_pos = read_be32(index->map, &index->map_pos);
229 xor_offset = read_u8(index->map, &index->map_pos);
230 flags = read_u8(index->map, &index->map_pos);
231
232 sha1 = nth_packed_object_sha1(index->pack, commit_idx_pos);
233
234 bitmap = read_bitmap_1(index);
235 if (!bitmap)
236 return -1;
237
238 if (xor_offset > MAX_XOR_OFFSET || xor_offset > i)
239 return error("Corrupted bitmap pack index");
240
241 if (xor_offset > 0) {
242 xor_bitmap = recent_bitmaps[(i - xor_offset) % MAX_XOR_OFFSET];
243
244 if (xor_bitmap == NULL)
245 return error("Invalid XOR offset in bitmap pack index");
246 }
247
248 recent_bitmaps[i % MAX_XOR_OFFSET] = store_bitmap(
249 index, bitmap, sha1, xor_bitmap, flags);
250 }
251
252 return 0;
253 }
254
255 static char *pack_bitmap_filename(struct packed_git *p)
256 {
257 char *idx_name;
258 int len;
259
260 len = strlen(p->pack_name) - strlen(".pack");
261 idx_name = xmalloc(len + strlen(".bitmap") + 1);
262
263 memcpy(idx_name, p->pack_name, len);
264 memcpy(idx_name + len, ".bitmap", strlen(".bitmap") + 1);
265
266 return idx_name;
267 }
268
269 static int open_pack_bitmap_1(struct packed_git *packfile)
270 {
271 int fd;
272 struct stat st;
273 char *idx_name;
274
275 if (open_pack_index(packfile))
276 return -1;
277
278 idx_name = pack_bitmap_filename(packfile);
279 fd = git_open_noatime(idx_name);
280 free(idx_name);
281
282 if (fd < 0)
283 return -1;
284
285 if (fstat(fd, &st)) {
286 close(fd);
287 return -1;
288 }
289
290 if (bitmap_git.pack) {
291 warning("ignoring extra bitmap file: %s", packfile->pack_name);
292 close(fd);
293 return -1;
294 }
295
296 bitmap_git.pack = packfile;
297 bitmap_git.map_size = xsize_t(st.st_size);
298 bitmap_git.map = xmmap(NULL, bitmap_git.map_size, PROT_READ, MAP_PRIVATE, fd, 0);
299 bitmap_git.map_pos = 0;
300 close(fd);
301
302 if (load_bitmap_header(&bitmap_git) < 0) {
303 munmap(bitmap_git.map, bitmap_git.map_size);
304 bitmap_git.map = NULL;
305 bitmap_git.map_size = 0;
306 return -1;
307 }
308
309 return 0;
310 }
311
312 static int load_pack_bitmap(void)
313 {
314 assert(bitmap_git.map && !bitmap_git.loaded);
315
316 bitmap_git.bitmaps = kh_init_sha1();
317 bitmap_git.ext_index.positions = kh_init_sha1_pos();
318 bitmap_git.reverse_index = revindex_for_pack(bitmap_git.pack);
319
320 if (!(bitmap_git.commits = read_bitmap_1(&bitmap_git)) ||
321 !(bitmap_git.trees = read_bitmap_1(&bitmap_git)) ||
322 !(bitmap_git.blobs = read_bitmap_1(&bitmap_git)) ||
323 !(bitmap_git.tags = read_bitmap_1(&bitmap_git)))
324 goto failed;
325
326 if (load_bitmap_entries_v1(&bitmap_git) < 0)
327 goto failed;
328
329 bitmap_git.loaded = 1;
330 return 0;
331
332 failed:
333 munmap(bitmap_git.map, bitmap_git.map_size);
334 bitmap_git.map = NULL;
335 bitmap_git.map_size = 0;
336 return -1;
337 }
338
339 static int open_pack_bitmap(void)
340 {
341 struct packed_git *p;
342 int ret = -1;
343
344 assert(!bitmap_git.map && !bitmap_git.loaded);
345
346 prepare_packed_git();
347 for (p = packed_git; p; p = p->next) {
348 if (open_pack_bitmap_1(p) == 0)
349 ret = 0;
350 }
351
352 return ret;
353 }
354
355 int prepare_bitmap_git(void)
356 {
357 if (bitmap_git.loaded)
358 return 0;
359
360 if (!open_pack_bitmap())
361 return load_pack_bitmap();
362
363 return -1;
364 }
365
366 struct include_data {
367 struct bitmap *base;
368 struct bitmap *seen;
369 };
370
371 static inline int bitmap_position_extended(const unsigned char *sha1)
372 {
373 khash_sha1_pos *positions = bitmap_git.ext_index.positions;
374 khiter_t pos = kh_get_sha1_pos(positions, sha1);
375
376 if (pos < kh_end(positions)) {
377 int bitmap_pos = kh_value(positions, pos);
378 return bitmap_pos + bitmap_git.pack->num_objects;
379 }
380
381 return -1;
382 }
383
384 static inline int bitmap_position_packfile(const unsigned char *sha1)
385 {
386 off_t offset = find_pack_entry_one(sha1, bitmap_git.pack);
387 if (!offset)
388 return -1;
389
390 return find_revindex_position(bitmap_git.reverse_index, offset);
391 }
392
393 static int bitmap_position(const unsigned char *sha1)
394 {
395 int pos = bitmap_position_packfile(sha1);
396 return (pos >= 0) ? pos : bitmap_position_extended(sha1);
397 }
398
399 static int ext_index_add_object(struct object *object, const char *name)
400 {
401 struct eindex *eindex = &bitmap_git.ext_index;
402
403 khiter_t hash_pos;
404 int hash_ret;
405 int bitmap_pos;
406
407 hash_pos = kh_put_sha1_pos(eindex->positions, object->sha1, &hash_ret);
408 if (hash_ret > 0) {
409 if (eindex->count >= eindex->alloc) {
410 eindex->alloc = (eindex->alloc + 16) * 3 / 2;
411 REALLOC_ARRAY(eindex->objects, eindex->alloc);
412 REALLOC_ARRAY(eindex->hashes, eindex->alloc);
413 }
414
415 bitmap_pos = eindex->count;
416 eindex->objects[eindex->count] = object;
417 eindex->hashes[eindex->count] = pack_name_hash(name);
418 kh_value(eindex->positions, hash_pos) = bitmap_pos;
419 eindex->count++;
420 } else {
421 bitmap_pos = kh_value(eindex->positions, hash_pos);
422 }
423
424 return bitmap_pos + bitmap_git.pack->num_objects;
425 }
426
427 static void show_object(struct object *object, const struct name_path *path,
428 const char *last, void *data)
429 {
430 struct bitmap *base = data;
431 int bitmap_pos;
432
433 bitmap_pos = bitmap_position(object->sha1);
434
435 if (bitmap_pos < 0) {
436 char *name = path_name(path, last);
437 bitmap_pos = ext_index_add_object(object, name);
438 free(name);
439 }
440
441 bitmap_set(base, bitmap_pos);
442 }
443
444 static void show_commit(struct commit *commit, void *data)
445 {
446 }
447
448 static int add_to_include_set(struct include_data *data,
449 const unsigned char *sha1,
450 int bitmap_pos)
451 {
452 khiter_t hash_pos;
453
454 if (data->seen && bitmap_get(data->seen, bitmap_pos))
455 return 0;
456
457 if (bitmap_get(data->base, bitmap_pos))
458 return 0;
459
460 hash_pos = kh_get_sha1(bitmap_git.bitmaps, sha1);
461 if (hash_pos < kh_end(bitmap_git.bitmaps)) {
462 struct stored_bitmap *st = kh_value(bitmap_git.bitmaps, hash_pos);
463 bitmap_or_ewah(data->base, lookup_stored_bitmap(st));
464 return 0;
465 }
466
467 bitmap_set(data->base, bitmap_pos);
468 return 1;
469 }
470
471 static int should_include(struct commit *commit, void *_data)
472 {
473 struct include_data *data = _data;
474 int bitmap_pos;
475
476 bitmap_pos = bitmap_position(commit->object.sha1);
477 if (bitmap_pos < 0)
478 bitmap_pos = ext_index_add_object((struct object *)commit, NULL);
479
480 if (!add_to_include_set(data, commit->object.sha1, bitmap_pos)) {
481 struct commit_list *parent = commit->parents;
482
483 while (parent) {
484 parent->item->object.flags |= SEEN;
485 parent = parent->next;
486 }
487
488 return 0;
489 }
490
491 return 1;
492 }
493
494 static struct bitmap *find_objects(struct rev_info *revs,
495 struct object_list *roots,
496 struct bitmap *seen)
497 {
498 struct bitmap *base = NULL;
499 int needs_walk = 0;
500
501 struct object_list *not_mapped = NULL;
502
503 /*
504 * Go through all the roots for the walk. The ones that have bitmaps
505 * on the bitmap index will be `or`ed together to form an initial
506 * global reachability analysis.
507 *
508 * The ones without bitmaps in the index will be stored in the
509 * `not_mapped_list` for further processing.
510 */
511 while (roots) {
512 struct object *object = roots->item;
513 roots = roots->next;
514
515 if (object->type == OBJ_COMMIT) {
516 khiter_t pos = kh_get_sha1(bitmap_git.bitmaps, object->sha1);
517
518 if (pos < kh_end(bitmap_git.bitmaps)) {
519 struct stored_bitmap *st = kh_value(bitmap_git.bitmaps, pos);
520 struct ewah_bitmap *or_with = lookup_stored_bitmap(st);
521
522 if (base == NULL)
523 base = ewah_to_bitmap(or_with);
524 else
525 bitmap_or_ewah(base, or_with);
526
527 object->flags |= SEEN;
528 continue;
529 }
530 }
531
532 object_list_insert(object, &not_mapped);
533 }
534
535 /*
536 * Best case scenario: We found bitmaps for all the roots,
537 * so the resulting `or` bitmap has the full reachability analysis
538 */
539 if (not_mapped == NULL)
540 return base;
541
542 roots = not_mapped;
543
544 /*
545 * Let's iterate through all the roots that don't have bitmaps to
546 * check if we can determine them to be reachable from the existing
547 * global bitmap.
548 *
549 * If we cannot find them in the existing global bitmap, we'll need
550 * to push them to an actual walk and run it until we can confirm
551 * they are reachable
552 */
553 while (roots) {
554 struct object *object = roots->item;
555 int pos;
556
557 roots = roots->next;
558 pos = bitmap_position(object->sha1);
559
560 if (pos < 0 || base == NULL || !bitmap_get(base, pos)) {
561 object->flags &= ~UNINTERESTING;
562 add_pending_object(revs, object, "");
563 needs_walk = 1;
564 } else {
565 object->flags |= SEEN;
566 }
567 }
568
569 if (needs_walk) {
570 struct include_data incdata;
571
572 if (base == NULL)
573 base = bitmap_new();
574
575 incdata.base = base;
576 incdata.seen = seen;
577
578 revs->include_check = should_include;
579 revs->include_check_data = &incdata;
580
581 if (prepare_revision_walk(revs))
582 die("revision walk setup failed");
583
584 traverse_commit_list(revs, show_commit, show_object, base);
585 }
586
587 return base;
588 }
589
590 static void show_extended_objects(struct bitmap *objects,
591 show_reachable_fn show_reach)
592 {
593 struct eindex *eindex = &bitmap_git.ext_index;
594 uint32_t i;
595
596 for (i = 0; i < eindex->count; ++i) {
597 struct object *obj;
598
599 if (!bitmap_get(objects, bitmap_git.pack->num_objects + i))
600 continue;
601
602 obj = eindex->objects[i];
603 show_reach(obj->sha1, obj->type, 0, eindex->hashes[i], NULL, 0);
604 }
605 }
606
607 static void show_objects_for_type(
608 struct bitmap *objects,
609 struct ewah_bitmap *type_filter,
610 enum object_type object_type,
611 show_reachable_fn show_reach)
612 {
613 size_t pos = 0, i = 0;
614 uint32_t offset;
615
616 struct ewah_iterator it;
617 eword_t filter;
618
619 if (bitmap_git.reuse_objects == bitmap_git.pack->num_objects)
620 return;
621
622 ewah_iterator_init(&it, type_filter);
623
624 while (i < objects->word_alloc && ewah_iterator_next(&filter, &it)) {
625 eword_t word = objects->words[i] & filter;
626
627 for (offset = 0; offset < BITS_IN_WORD; ++offset) {
628 const unsigned char *sha1;
629 struct revindex_entry *entry;
630 uint32_t hash = 0;
631
632 if ((word >> offset) == 0)
633 break;
634
635 offset += ewah_bit_ctz64(word >> offset);
636
637 if (pos + offset < bitmap_git.reuse_objects)
638 continue;
639
640 entry = &bitmap_git.reverse_index->revindex[pos + offset];
641 sha1 = nth_packed_object_sha1(bitmap_git.pack, entry->nr);
642
643 if (bitmap_git.hashes)
644 hash = ntohl(bitmap_git.hashes[entry->nr]);
645
646 show_reach(sha1, object_type, 0, hash, bitmap_git.pack, entry->offset);
647 }
648
649 pos += BITS_IN_WORD;
650 i++;
651 }
652 }
653
654 static int in_bitmapped_pack(struct object_list *roots)
655 {
656 while (roots) {
657 struct object *object = roots->item;
658 roots = roots->next;
659
660 if (find_pack_entry_one(object->sha1, bitmap_git.pack) > 0)
661 return 1;
662 }
663
664 return 0;
665 }
666
667 int prepare_bitmap_walk(struct rev_info *revs)
668 {
669 unsigned int i;
670 unsigned int pending_nr = revs->pending.nr;
671 struct object_array_entry *pending_e = revs->pending.objects;
672
673 struct object_list *wants = NULL;
674 struct object_list *haves = NULL;
675
676 struct bitmap *wants_bitmap = NULL;
677 struct bitmap *haves_bitmap = NULL;
678
679 if (!bitmap_git.loaded) {
680 /* try to open a bitmapped pack, but don't parse it yet
681 * because we may not need to use it */
682 if (open_pack_bitmap() < 0)
683 return -1;
684 }
685
686 for (i = 0; i < pending_nr; ++i) {
687 struct object *object = pending_e[i].item;
688
689 if (object->type == OBJ_NONE)
690 parse_object_or_die(object->sha1, NULL);
691
692 while (object->type == OBJ_TAG) {
693 struct tag *tag = (struct tag *) object;
694
695 if (object->flags & UNINTERESTING)
696 object_list_insert(object, &haves);
697 else
698 object_list_insert(object, &wants);
699
700 if (!tag->tagged)
701 die("bad tag");
702 object = parse_object_or_die(tag->tagged->sha1, NULL);
703 }
704
705 if (object->flags & UNINTERESTING)
706 object_list_insert(object, &haves);
707 else
708 object_list_insert(object, &wants);
709 }
710
711 /*
712 * if we have a HAVES list, but none of those haves is contained
713 * in the packfile that has a bitmap, we don't have anything to
714 * optimize here
715 */
716 if (haves && !in_bitmapped_pack(haves))
717 return -1;
718
719 /* if we don't want anything, we're done here */
720 if (!wants)
721 return -1;
722
723 /*
724 * now we're going to use bitmaps, so load the actual bitmap entries
725 * from disk. this is the point of no return; after this the rev_list
726 * becomes invalidated and we must perform the revwalk through bitmaps
727 */
728 if (!bitmap_git.loaded && load_pack_bitmap() < 0)
729 return -1;
730
731 revs->pending.nr = 0;
732 revs->pending.alloc = 0;
733 revs->pending.objects = NULL;
734
735 if (haves) {
736 revs->ignore_missing_links = 1;
737 haves_bitmap = find_objects(revs, haves, NULL);
738 reset_revision_walk();
739 revs->ignore_missing_links = 0;
740
741 if (haves_bitmap == NULL)
742 die("BUG: failed to perform bitmap walk");
743 }
744
745 wants_bitmap = find_objects(revs, wants, haves_bitmap);
746
747 if (!wants_bitmap)
748 die("BUG: failed to perform bitmap walk");
749
750 if (haves_bitmap)
751 bitmap_and_not(wants_bitmap, haves_bitmap);
752
753 bitmap_git.result = wants_bitmap;
754
755 bitmap_free(haves_bitmap);
756 return 0;
757 }
758
759 int reuse_partial_packfile_from_bitmap(struct packed_git **packfile,
760 uint32_t *entries,
761 off_t *up_to)
762 {
763 /*
764 * Reuse the packfile content if we need more than
765 * 90% of its objects
766 */
767 static const double REUSE_PERCENT = 0.9;
768
769 struct bitmap *result = bitmap_git.result;
770 uint32_t reuse_threshold;
771 uint32_t i, reuse_objects = 0;
772
773 assert(result);
774
775 for (i = 0; i < result->word_alloc; ++i) {
776 if (result->words[i] != (eword_t)~0) {
777 reuse_objects += ewah_bit_ctz64(~result->words[i]);
778 break;
779 }
780
781 reuse_objects += BITS_IN_WORD;
782 }
783
784 #ifdef GIT_BITMAP_DEBUG
785 {
786 const unsigned char *sha1;
787 struct revindex_entry *entry;
788
789 entry = &bitmap_git.reverse_index->revindex[reuse_objects];
790 sha1 = nth_packed_object_sha1(bitmap_git.pack, entry->nr);
791
792 fprintf(stderr, "Failed to reuse at %d (%016llx)\n",
793 reuse_objects, result->words[i]);
794 fprintf(stderr, " %s\n", sha1_to_hex(sha1));
795 }
796 #endif
797
798 if (!reuse_objects)
799 return -1;
800
801 if (reuse_objects >= bitmap_git.pack->num_objects) {
802 bitmap_git.reuse_objects = *entries = bitmap_git.pack->num_objects;
803 *up_to = -1; /* reuse the full pack */
804 *packfile = bitmap_git.pack;
805 return 0;
806 }
807
808 reuse_threshold = bitmap_popcount(bitmap_git.result) * REUSE_PERCENT;
809
810 if (reuse_objects < reuse_threshold)
811 return -1;
812
813 bitmap_git.reuse_objects = *entries = reuse_objects;
814 *up_to = bitmap_git.reverse_index->revindex[reuse_objects].offset;
815 *packfile = bitmap_git.pack;
816
817 return 0;
818 }
819
820 void traverse_bitmap_commit_list(show_reachable_fn show_reachable)
821 {
822 assert(bitmap_git.result);
823
824 show_objects_for_type(bitmap_git.result, bitmap_git.commits,
825 OBJ_COMMIT, show_reachable);
826 show_objects_for_type(bitmap_git.result, bitmap_git.trees,
827 OBJ_TREE, show_reachable);
828 show_objects_for_type(bitmap_git.result, bitmap_git.blobs,
829 OBJ_BLOB, show_reachable);
830 show_objects_for_type(bitmap_git.result, bitmap_git.tags,
831 OBJ_TAG, show_reachable);
832
833 show_extended_objects(bitmap_git.result, show_reachable);
834
835 bitmap_free(bitmap_git.result);
836 bitmap_git.result = NULL;
837 }
838
839 static uint32_t count_object_type(struct bitmap *objects,
840 enum object_type type)
841 {
842 struct eindex *eindex = &bitmap_git.ext_index;
843
844 uint32_t i = 0, count = 0;
845 struct ewah_iterator it;
846 eword_t filter;
847
848 switch (type) {
849 case OBJ_COMMIT:
850 ewah_iterator_init(&it, bitmap_git.commits);
851 break;
852
853 case OBJ_TREE:
854 ewah_iterator_init(&it, bitmap_git.trees);
855 break;
856
857 case OBJ_BLOB:
858 ewah_iterator_init(&it, bitmap_git.blobs);
859 break;
860
861 case OBJ_TAG:
862 ewah_iterator_init(&it, bitmap_git.tags);
863 break;
864
865 default:
866 return 0;
867 }
868
869 while (i < objects->word_alloc && ewah_iterator_next(&filter, &it)) {
870 eword_t word = objects->words[i++] & filter;
871 count += ewah_bit_popcount64(word);
872 }
873
874 for (i = 0; i < eindex->count; ++i) {
875 if (eindex->objects[i]->type == type &&
876 bitmap_get(objects, bitmap_git.pack->num_objects + i))
877 count++;
878 }
879
880 return count;
881 }
882
883 void count_bitmap_commit_list(uint32_t *commits, uint32_t *trees,
884 uint32_t *blobs, uint32_t *tags)
885 {
886 assert(bitmap_git.result);
887
888 if (commits)
889 *commits = count_object_type(bitmap_git.result, OBJ_COMMIT);
890
891 if (trees)
892 *trees = count_object_type(bitmap_git.result, OBJ_TREE);
893
894 if (blobs)
895 *blobs = count_object_type(bitmap_git.result, OBJ_BLOB);
896
897 if (tags)
898 *tags = count_object_type(bitmap_git.result, OBJ_TAG);
899 }
900
901 struct bitmap_test_data {
902 struct bitmap *base;
903 struct progress *prg;
904 size_t seen;
905 };
906
907 static void test_show_object(struct object *object,
908 const struct name_path *path,
909 const char *last, void *data)
910 {
911 struct bitmap_test_data *tdata = data;
912 int bitmap_pos;
913
914 bitmap_pos = bitmap_position(object->sha1);
915 if (bitmap_pos < 0)
916 die("Object not in bitmap: %s\n", sha1_to_hex(object->sha1));
917
918 bitmap_set(tdata->base, bitmap_pos);
919 display_progress(tdata->prg, ++tdata->seen);
920 }
921
922 static void test_show_commit(struct commit *commit, void *data)
923 {
924 struct bitmap_test_data *tdata = data;
925 int bitmap_pos;
926
927 bitmap_pos = bitmap_position(commit->object.sha1);
928 if (bitmap_pos < 0)
929 die("Object not in bitmap: %s\n", sha1_to_hex(commit->object.sha1));
930
931 bitmap_set(tdata->base, bitmap_pos);
932 display_progress(tdata->prg, ++tdata->seen);
933 }
934
935 void test_bitmap_walk(struct rev_info *revs)
936 {
937 struct object *root;
938 struct bitmap *result = NULL;
939 khiter_t pos;
940 size_t result_popcnt;
941 struct bitmap_test_data tdata;
942
943 if (prepare_bitmap_git())
944 die("failed to load bitmap indexes");
945
946 if (revs->pending.nr != 1)
947 die("you must specify exactly one commit to test");
948
949 fprintf(stderr, "Bitmap v%d test (%d entries loaded)\n",
950 bitmap_git.version, bitmap_git.entry_count);
951
952 root = revs->pending.objects[0].item;
953 pos = kh_get_sha1(bitmap_git.bitmaps, root->sha1);
954
955 if (pos < kh_end(bitmap_git.bitmaps)) {
956 struct stored_bitmap *st = kh_value(bitmap_git.bitmaps, pos);
957 struct ewah_bitmap *bm = lookup_stored_bitmap(st);
958
959 fprintf(stderr, "Found bitmap for %s. %d bits / %08x checksum\n",
960 sha1_to_hex(root->sha1), (int)bm->bit_size, ewah_checksum(bm));
961
962 result = ewah_to_bitmap(bm);
963 }
964
965 if (result == NULL)
966 die("Commit %s doesn't have an indexed bitmap", sha1_to_hex(root->sha1));
967
968 revs->tag_objects = 1;
969 revs->tree_objects = 1;
970 revs->blob_objects = 1;
971
972 result_popcnt = bitmap_popcount(result);
973
974 if (prepare_revision_walk(revs))
975 die("revision walk setup failed");
976
977 tdata.base = bitmap_new();
978 tdata.prg = start_progress("Verifying bitmap entries", result_popcnt);
979 tdata.seen = 0;
980
981 traverse_commit_list(revs, &test_show_commit, &test_show_object, &tdata);
982
983 stop_progress(&tdata.prg);
984
985 if (bitmap_equals(result, tdata.base))
986 fprintf(stderr, "OK!\n");
987 else
988 fprintf(stderr, "Mismatch!\n");
989
990 free(result);
991 }
992
993 static int rebuild_bitmap(uint32_t *reposition,
994 struct ewah_bitmap *source,
995 struct bitmap *dest)
996 {
997 uint32_t pos = 0;
998 struct ewah_iterator it;
999 eword_t word;
1000
1001 ewah_iterator_init(&it, source);
1002
1003 while (ewah_iterator_next(&word, &it)) {
1004 uint32_t offset, bit_pos;
1005
1006 for (offset = 0; offset < BITS_IN_WORD; ++offset) {
1007 if ((word >> offset) == 0)
1008 break;
1009
1010 offset += ewah_bit_ctz64(word >> offset);
1011
1012 bit_pos = reposition[pos + offset];
1013 if (bit_pos > 0)
1014 bitmap_set(dest, bit_pos - 1);
1015 else /* can't reuse, we don't have the object */
1016 return -1;
1017 }
1018
1019 pos += BITS_IN_WORD;
1020 }
1021 return 0;
1022 }
1023
1024 int rebuild_existing_bitmaps(struct packing_data *mapping,
1025 khash_sha1 *reused_bitmaps,
1026 int show_progress)
1027 {
1028 uint32_t i, num_objects;
1029 uint32_t *reposition;
1030 struct bitmap *rebuild;
1031 struct stored_bitmap *stored;
1032 struct progress *progress = NULL;
1033
1034 khiter_t hash_pos;
1035 int hash_ret;
1036
1037 if (prepare_bitmap_git() < 0)
1038 return -1;
1039
1040 num_objects = bitmap_git.pack->num_objects;
1041 reposition = xcalloc(num_objects, sizeof(uint32_t));
1042
1043 for (i = 0; i < num_objects; ++i) {
1044 const unsigned char *sha1;
1045 struct revindex_entry *entry;
1046 struct object_entry *oe;
1047
1048 entry = &bitmap_git.reverse_index->revindex[i];
1049 sha1 = nth_packed_object_sha1(bitmap_git.pack, entry->nr);
1050 oe = packlist_find(mapping, sha1, NULL);
1051
1052 if (oe)
1053 reposition[i] = oe->in_pack_pos + 1;
1054 }
1055
1056 rebuild = bitmap_new();
1057 i = 0;
1058
1059 if (show_progress)
1060 progress = start_progress("Reusing bitmaps", 0);
1061
1062 kh_foreach_value(bitmap_git.bitmaps, stored, {
1063 if (stored->flags & BITMAP_FLAG_REUSE) {
1064 if (!rebuild_bitmap(reposition,
1065 lookup_stored_bitmap(stored),
1066 rebuild)) {
1067 hash_pos = kh_put_sha1(reused_bitmaps,
1068 stored->sha1,
1069 &hash_ret);
1070 kh_value(reused_bitmaps, hash_pos) =
1071 bitmap_to_ewah(rebuild);
1072 }
1073 bitmap_reset(rebuild);
1074 display_progress(progress, ++i);
1075 }
1076 });
1077
1078 stop_progress(&progress);
1079
1080 free(reposition);
1081 bitmap_free(rebuild);
1082 return 0;
1083 }