promisor-remote: skip move_to_tail when no-op
[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 #include "packfile.h"
13 #include "repository.h"
14 #include "object-store.h"
15
16 /*
17 * An entry on the bitmap index, representing the bitmap for a given
18 * commit.
19 */
20 struct stored_bitmap {
21 struct object_id oid;
22 struct ewah_bitmap *root;
23 struct stored_bitmap *xor;
24 int flags;
25 };
26
27 /*
28 * The active bitmap index for a repository. By design, repositories only have
29 * a single bitmap index available (the index for the biggest packfile in
30 * the repository), since bitmap indexes need full closure.
31 *
32 * If there is more than one bitmap index available (e.g. because of alternates),
33 * the active bitmap index is the largest one.
34 */
35 struct bitmap_index {
36 /* Packfile to which this bitmap index belongs to */
37 struct packed_git *pack;
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 object ID -> `stored_bitmap` for all the bitmapped commits */
64 kh_oid_map_t *bitmaps;
65
66 /* Number of bitmapped commits */
67 uint32_t entry_count;
68
69 /* If not NULL, this is a name-hash cache pointing into map. */
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 kh_oid_pos_t *positions;
84 } ext_index;
85
86 /* Bitmap result of the last performed walk */
87 struct bitmap *result;
88
89 /* "have" bitmap from the last performed walk */
90 struct bitmap *haves;
91
92 /* Version of the bitmap index */
93 unsigned int version;
94 };
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 ssize_t 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) + the_hash_algo->rawsz)
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 - the_hash_algo->rawsz;
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) - GIT_MAX_RAWSZ + the_hash_algo->rawsz;
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 *hash,
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 oidread(&stored->oid, hash);
185
186 hash_pos = kh_put_oid_map(index->bitmaps, stored->oid, &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", hash_to_hex(hash));
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 #define MAX_XOR_OFFSET 160
213
214 static int load_bitmap_entries_v1(struct bitmap_index *index)
215 {
216 uint32_t i;
217 struct stored_bitmap *recent_bitmaps[MAX_XOR_OFFSET] = { NULL };
218
219 for (i = 0; i < index->entry_count; ++i) {
220 int xor_offset, flags;
221 struct ewah_bitmap *bitmap = NULL;
222 struct stored_bitmap *xor_bitmap = NULL;
223 uint32_t commit_idx_pos;
224 const unsigned char *sha1;
225
226 commit_idx_pos = read_be32(index->map, &index->map_pos);
227 xor_offset = read_u8(index->map, &index->map_pos);
228 flags = read_u8(index->map, &index->map_pos);
229
230 sha1 = nth_packed_object_sha1(index->pack, commit_idx_pos);
231
232 bitmap = read_bitmap_1(index);
233 if (!bitmap)
234 return -1;
235
236 if (xor_offset > MAX_XOR_OFFSET || xor_offset > i)
237 return error("Corrupted bitmap pack index");
238
239 if (xor_offset > 0) {
240 xor_bitmap = recent_bitmaps[(i - xor_offset) % MAX_XOR_OFFSET];
241
242 if (xor_bitmap == NULL)
243 return error("Invalid XOR offset in bitmap pack index");
244 }
245
246 recent_bitmaps[i % MAX_XOR_OFFSET] = store_bitmap(
247 index, bitmap, sha1, xor_bitmap, flags);
248 }
249
250 return 0;
251 }
252
253 static char *pack_bitmap_filename(struct packed_git *p)
254 {
255 size_t len;
256
257 if (!strip_suffix(p->pack_name, ".pack", &len))
258 BUG("pack_name does not end in .pack");
259 return xstrfmt("%.*s.bitmap", (int)len, p->pack_name);
260 }
261
262 static int open_pack_bitmap_1(struct bitmap_index *bitmap_git, struct packed_git *packfile)
263 {
264 int fd;
265 struct stat st;
266 char *idx_name;
267
268 if (open_pack_index(packfile))
269 return -1;
270
271 idx_name = pack_bitmap_filename(packfile);
272 fd = git_open(idx_name);
273 free(idx_name);
274
275 if (fd < 0)
276 return -1;
277
278 if (fstat(fd, &st)) {
279 close(fd);
280 return -1;
281 }
282
283 if (bitmap_git->pack) {
284 warning("ignoring extra bitmap file: %s", packfile->pack_name);
285 close(fd);
286 return -1;
287 }
288
289 bitmap_git->pack = packfile;
290 bitmap_git->map_size = xsize_t(st.st_size);
291 bitmap_git->map = xmmap(NULL, bitmap_git->map_size, PROT_READ, MAP_PRIVATE, fd, 0);
292 bitmap_git->map_pos = 0;
293 close(fd);
294
295 if (load_bitmap_header(bitmap_git) < 0) {
296 munmap(bitmap_git->map, bitmap_git->map_size);
297 bitmap_git->map = NULL;
298 bitmap_git->map_size = 0;
299 return -1;
300 }
301
302 return 0;
303 }
304
305 static int load_pack_bitmap(struct bitmap_index *bitmap_git)
306 {
307 assert(bitmap_git->map);
308
309 bitmap_git->bitmaps = kh_init_oid_map();
310 bitmap_git->ext_index.positions = kh_init_oid_pos();
311 if (load_pack_revindex(bitmap_git->pack))
312 goto failed;
313
314 if (!(bitmap_git->commits = read_bitmap_1(bitmap_git)) ||
315 !(bitmap_git->trees = read_bitmap_1(bitmap_git)) ||
316 !(bitmap_git->blobs = read_bitmap_1(bitmap_git)) ||
317 !(bitmap_git->tags = read_bitmap_1(bitmap_git)))
318 goto failed;
319
320 if (load_bitmap_entries_v1(bitmap_git) < 0)
321 goto failed;
322
323 return 0;
324
325 failed:
326 munmap(bitmap_git->map, bitmap_git->map_size);
327 bitmap_git->map = NULL;
328 bitmap_git->map_size = 0;
329 return -1;
330 }
331
332 static int open_pack_bitmap(struct repository *r,
333 struct bitmap_index *bitmap_git)
334 {
335 struct packed_git *p;
336 int ret = -1;
337
338 assert(!bitmap_git->map);
339
340 for (p = get_all_packs(r); p; p = p->next) {
341 if (open_pack_bitmap_1(bitmap_git, p) == 0)
342 ret = 0;
343 }
344
345 return ret;
346 }
347
348 struct bitmap_index *prepare_bitmap_git(struct repository *r)
349 {
350 struct bitmap_index *bitmap_git = xcalloc(1, sizeof(*bitmap_git));
351
352 if (!open_pack_bitmap(r, bitmap_git) && !load_pack_bitmap(bitmap_git))
353 return bitmap_git;
354
355 free_bitmap_index(bitmap_git);
356 return NULL;
357 }
358
359 struct include_data {
360 struct bitmap_index *bitmap_git;
361 struct bitmap *base;
362 struct bitmap *seen;
363 };
364
365 static inline int bitmap_position_extended(struct bitmap_index *bitmap_git,
366 const struct object_id *oid)
367 {
368 khash_oid_pos *positions = bitmap_git->ext_index.positions;
369 khiter_t pos = kh_get_oid_pos(positions, *oid);
370
371 if (pos < kh_end(positions)) {
372 int bitmap_pos = kh_value(positions, pos);
373 return bitmap_pos + bitmap_git->pack->num_objects;
374 }
375
376 return -1;
377 }
378
379 static inline int bitmap_position_packfile(struct bitmap_index *bitmap_git,
380 const struct object_id *oid)
381 {
382 off_t offset = find_pack_entry_one(oid->hash, bitmap_git->pack);
383 if (!offset)
384 return -1;
385
386 return find_revindex_position(bitmap_git->pack, offset);
387 }
388
389 static int bitmap_position(struct bitmap_index *bitmap_git,
390 const struct object_id *oid)
391 {
392 int pos = bitmap_position_packfile(bitmap_git, oid);
393 return (pos >= 0) ? pos : bitmap_position_extended(bitmap_git, oid);
394 }
395
396 static int ext_index_add_object(struct bitmap_index *bitmap_git,
397 struct object *object, const char *name)
398 {
399 struct eindex *eindex = &bitmap_git->ext_index;
400
401 khiter_t hash_pos;
402 int hash_ret;
403 int bitmap_pos;
404
405 hash_pos = kh_put_oid_pos(eindex->positions, object->oid, &hash_ret);
406 if (hash_ret > 0) {
407 if (eindex->count >= eindex->alloc) {
408 eindex->alloc = (eindex->alloc + 16) * 3 / 2;
409 REALLOC_ARRAY(eindex->objects, eindex->alloc);
410 REALLOC_ARRAY(eindex->hashes, eindex->alloc);
411 }
412
413 bitmap_pos = eindex->count;
414 eindex->objects[eindex->count] = object;
415 eindex->hashes[eindex->count] = pack_name_hash(name);
416 kh_value(eindex->positions, hash_pos) = bitmap_pos;
417 eindex->count++;
418 } else {
419 bitmap_pos = kh_value(eindex->positions, hash_pos);
420 }
421
422 return bitmap_pos + bitmap_git->pack->num_objects;
423 }
424
425 struct bitmap_show_data {
426 struct bitmap_index *bitmap_git;
427 struct bitmap *base;
428 };
429
430 static void show_object(struct object *object, const char *name, void *data_)
431 {
432 struct bitmap_show_data *data = data_;
433 int bitmap_pos;
434
435 bitmap_pos = bitmap_position(data->bitmap_git, &object->oid);
436
437 if (bitmap_pos < 0)
438 bitmap_pos = ext_index_add_object(data->bitmap_git, object,
439 name);
440
441 bitmap_set(data->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 bitmap_index *bitmap_git,
449 struct include_data *data,
450 const struct object_id *oid,
451 int bitmap_pos)
452 {
453 khiter_t hash_pos;
454
455 if (data->seen && bitmap_get(data->seen, bitmap_pos))
456 return 0;
457
458 if (bitmap_get(data->base, bitmap_pos))
459 return 0;
460
461 hash_pos = kh_get_oid_map(bitmap_git->bitmaps, *oid);
462 if (hash_pos < kh_end(bitmap_git->bitmaps)) {
463 struct stored_bitmap *st = kh_value(bitmap_git->bitmaps, hash_pos);
464 bitmap_or_ewah(data->base, lookup_stored_bitmap(st));
465 return 0;
466 }
467
468 bitmap_set(data->base, bitmap_pos);
469 return 1;
470 }
471
472 static int should_include(struct commit *commit, void *_data)
473 {
474 struct include_data *data = _data;
475 int bitmap_pos;
476
477 bitmap_pos = bitmap_position(data->bitmap_git, &commit->object.oid);
478 if (bitmap_pos < 0)
479 bitmap_pos = ext_index_add_object(data->bitmap_git,
480 (struct object *)commit,
481 NULL);
482
483 if (!add_to_include_set(data->bitmap_git, data, &commit->object.oid,
484 bitmap_pos)) {
485 struct commit_list *parent = commit->parents;
486
487 while (parent) {
488 parent->item->object.flags |= SEEN;
489 parent = parent->next;
490 }
491
492 return 0;
493 }
494
495 return 1;
496 }
497
498 static struct bitmap *find_objects(struct bitmap_index *bitmap_git,
499 struct rev_info *revs,
500 struct object_list *roots,
501 struct bitmap *seen)
502 {
503 struct bitmap *base = NULL;
504 int needs_walk = 0;
505
506 struct object_list *not_mapped = NULL;
507
508 /*
509 * Go through all the roots for the walk. The ones that have bitmaps
510 * on the bitmap index will be `or`ed together to form an initial
511 * global reachability analysis.
512 *
513 * The ones without bitmaps in the index will be stored in the
514 * `not_mapped_list` for further processing.
515 */
516 while (roots) {
517 struct object *object = roots->item;
518 roots = roots->next;
519
520 if (object->type == OBJ_COMMIT) {
521 khiter_t pos = kh_get_oid_map(bitmap_git->bitmaps, object->oid);
522
523 if (pos < kh_end(bitmap_git->bitmaps)) {
524 struct stored_bitmap *st = kh_value(bitmap_git->bitmaps, pos);
525 struct ewah_bitmap *or_with = lookup_stored_bitmap(st);
526
527 if (base == NULL)
528 base = ewah_to_bitmap(or_with);
529 else
530 bitmap_or_ewah(base, or_with);
531
532 object->flags |= SEEN;
533 continue;
534 }
535 }
536
537 object_list_insert(object, &not_mapped);
538 }
539
540 /*
541 * Best case scenario: We found bitmaps for all the roots,
542 * so the resulting `or` bitmap has the full reachability analysis
543 */
544 if (not_mapped == NULL)
545 return base;
546
547 roots = not_mapped;
548
549 /*
550 * Let's iterate through all the roots that don't have bitmaps to
551 * check if we can determine them to be reachable from the existing
552 * global bitmap.
553 *
554 * If we cannot find them in the existing global bitmap, we'll need
555 * to push them to an actual walk and run it until we can confirm
556 * they are reachable
557 */
558 while (roots) {
559 struct object *object = roots->item;
560 int pos;
561
562 roots = roots->next;
563 pos = bitmap_position(bitmap_git, &object->oid);
564
565 if (pos < 0 || base == NULL || !bitmap_get(base, pos)) {
566 object->flags &= ~UNINTERESTING;
567 add_pending_object(revs, object, "");
568 needs_walk = 1;
569 } else {
570 object->flags |= SEEN;
571 }
572 }
573
574 if (needs_walk) {
575 struct include_data incdata;
576 struct bitmap_show_data show_data;
577
578 if (base == NULL)
579 base = bitmap_new();
580
581 incdata.bitmap_git = bitmap_git;
582 incdata.base = base;
583 incdata.seen = seen;
584
585 revs->include_check = should_include;
586 revs->include_check_data = &incdata;
587
588 if (prepare_revision_walk(revs))
589 die("revision walk setup failed");
590
591 show_data.bitmap_git = bitmap_git;
592 show_data.base = base;
593
594 traverse_commit_list(revs, show_commit, show_object,
595 &show_data);
596 }
597
598 return base;
599 }
600
601 static void show_extended_objects(struct bitmap_index *bitmap_git,
602 show_reachable_fn show_reach)
603 {
604 struct bitmap *objects = bitmap_git->result;
605 struct eindex *eindex = &bitmap_git->ext_index;
606 uint32_t i;
607
608 for (i = 0; i < eindex->count; ++i) {
609 struct object *obj;
610
611 if (!bitmap_get(objects, bitmap_git->pack->num_objects + i))
612 continue;
613
614 obj = eindex->objects[i];
615 show_reach(&obj->oid, obj->type, 0, eindex->hashes[i], NULL, 0);
616 }
617 }
618
619 static void show_objects_for_type(
620 struct bitmap_index *bitmap_git,
621 struct ewah_bitmap *type_filter,
622 enum object_type object_type,
623 show_reachable_fn show_reach)
624 {
625 size_t pos = 0, i = 0;
626 uint32_t offset;
627
628 struct ewah_iterator it;
629 eword_t filter;
630
631 struct bitmap *objects = bitmap_git->result;
632
633 if (bitmap_git->reuse_objects == bitmap_git->pack->num_objects)
634 return;
635
636 ewah_iterator_init(&it, type_filter);
637
638 while (i < objects->word_alloc && ewah_iterator_next(&filter, &it)) {
639 eword_t word = objects->words[i] & filter;
640
641 for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
642 struct object_id oid;
643 struct revindex_entry *entry;
644 uint32_t hash = 0;
645
646 if ((word >> offset) == 0)
647 break;
648
649 offset += ewah_bit_ctz64(word >> offset);
650
651 if (pos + offset < bitmap_git->reuse_objects)
652 continue;
653
654 entry = &bitmap_git->pack->revindex[pos + offset];
655 nth_packed_object_oid(&oid, bitmap_git->pack, entry->nr);
656
657 if (bitmap_git->hashes)
658 hash = get_be32(bitmap_git->hashes + entry->nr);
659
660 show_reach(&oid, object_type, 0, hash, bitmap_git->pack, entry->offset);
661 }
662
663 pos += BITS_IN_EWORD;
664 i++;
665 }
666 }
667
668 static int in_bitmapped_pack(struct bitmap_index *bitmap_git,
669 struct object_list *roots)
670 {
671 while (roots) {
672 struct object *object = roots->item;
673 roots = roots->next;
674
675 if (find_pack_entry_one(object->oid.hash, bitmap_git->pack) > 0)
676 return 1;
677 }
678
679 return 0;
680 }
681
682 struct bitmap_index *prepare_bitmap_walk(struct rev_info *revs)
683 {
684 unsigned int i;
685
686 struct object_list *wants = NULL;
687 struct object_list *haves = NULL;
688
689 struct bitmap *wants_bitmap = NULL;
690 struct bitmap *haves_bitmap = NULL;
691
692 struct bitmap_index *bitmap_git = xcalloc(1, sizeof(*bitmap_git));
693 /* try to open a bitmapped pack, but don't parse it yet
694 * because we may not need to use it */
695 if (open_pack_bitmap(revs->repo, bitmap_git) < 0)
696 goto cleanup;
697
698 for (i = 0; i < revs->pending.nr; ++i) {
699 struct object *object = revs->pending.objects[i].item;
700
701 if (object->type == OBJ_NONE)
702 parse_object_or_die(&object->oid, NULL);
703
704 while (object->type == OBJ_TAG) {
705 struct tag *tag = (struct tag *) object;
706
707 if (object->flags & UNINTERESTING)
708 object_list_insert(object, &haves);
709 else
710 object_list_insert(object, &wants);
711
712 if (!tag->tagged)
713 die("bad tag");
714 object = parse_object_or_die(&tag->tagged->oid, NULL);
715 }
716
717 if (object->flags & UNINTERESTING)
718 object_list_insert(object, &haves);
719 else
720 object_list_insert(object, &wants);
721 }
722
723 /*
724 * if we have a HAVES list, but none of those haves is contained
725 * in the packfile that has a bitmap, we don't have anything to
726 * optimize here
727 */
728 if (haves && !in_bitmapped_pack(bitmap_git, haves))
729 goto cleanup;
730
731 /* if we don't want anything, we're done here */
732 if (!wants)
733 goto cleanup;
734
735 /*
736 * now we're going to use bitmaps, so load the actual bitmap entries
737 * from disk. this is the point of no return; after this the rev_list
738 * becomes invalidated and we must perform the revwalk through bitmaps
739 */
740 if (load_pack_bitmap(bitmap_git) < 0)
741 goto cleanup;
742
743 object_array_clear(&revs->pending);
744
745 if (haves) {
746 revs->ignore_missing_links = 1;
747 haves_bitmap = find_objects(bitmap_git, revs, haves, NULL);
748 reset_revision_walk();
749 revs->ignore_missing_links = 0;
750
751 if (haves_bitmap == NULL)
752 BUG("failed to perform bitmap walk");
753 }
754
755 wants_bitmap = find_objects(bitmap_git, revs, wants, haves_bitmap);
756
757 if (!wants_bitmap)
758 BUG("failed to perform bitmap walk");
759
760 if (haves_bitmap)
761 bitmap_and_not(wants_bitmap, haves_bitmap);
762
763 bitmap_git->result = wants_bitmap;
764 bitmap_git->haves = haves_bitmap;
765
766 return bitmap_git;
767
768 cleanup:
769 free_bitmap_index(bitmap_git);
770 return NULL;
771 }
772
773 int reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git,
774 struct packed_git **packfile,
775 uint32_t *entries,
776 off_t *up_to)
777 {
778 /*
779 * Reuse the packfile content if we need more than
780 * 90% of its objects
781 */
782 static const double REUSE_PERCENT = 0.9;
783
784 struct bitmap *result = bitmap_git->result;
785 uint32_t reuse_threshold;
786 uint32_t i, reuse_objects = 0;
787
788 assert(result);
789
790 for (i = 0; i < result->word_alloc; ++i) {
791 if (result->words[i] != (eword_t)~0) {
792 reuse_objects += ewah_bit_ctz64(~result->words[i]);
793 break;
794 }
795
796 reuse_objects += BITS_IN_EWORD;
797 }
798
799 #ifdef GIT_BITMAP_DEBUG
800 {
801 const unsigned char *sha1;
802 struct revindex_entry *entry;
803
804 entry = &bitmap_git->reverse_index->revindex[reuse_objects];
805 sha1 = nth_packed_object_sha1(bitmap_git->pack, entry->nr);
806
807 fprintf(stderr, "Failed to reuse at %d (%016llx)\n",
808 reuse_objects, result->words[i]);
809 fprintf(stderr, " %s\n", hash_to_hex(sha1));
810 }
811 #endif
812
813 if (!reuse_objects)
814 return -1;
815
816 if (reuse_objects >= bitmap_git->pack->num_objects) {
817 bitmap_git->reuse_objects = *entries = bitmap_git->pack->num_objects;
818 *up_to = -1; /* reuse the full pack */
819 *packfile = bitmap_git->pack;
820 return 0;
821 }
822
823 reuse_threshold = bitmap_popcount(bitmap_git->result) * REUSE_PERCENT;
824
825 if (reuse_objects < reuse_threshold)
826 return -1;
827
828 bitmap_git->reuse_objects = *entries = reuse_objects;
829 *up_to = bitmap_git->pack->revindex[reuse_objects].offset;
830 *packfile = bitmap_git->pack;
831
832 return 0;
833 }
834
835 void traverse_bitmap_commit_list(struct bitmap_index *bitmap_git,
836 show_reachable_fn show_reachable)
837 {
838 assert(bitmap_git->result);
839
840 show_objects_for_type(bitmap_git, bitmap_git->commits,
841 OBJ_COMMIT, show_reachable);
842 show_objects_for_type(bitmap_git, bitmap_git->trees,
843 OBJ_TREE, show_reachable);
844 show_objects_for_type(bitmap_git, bitmap_git->blobs,
845 OBJ_BLOB, show_reachable);
846 show_objects_for_type(bitmap_git, bitmap_git->tags,
847 OBJ_TAG, show_reachable);
848
849 show_extended_objects(bitmap_git, show_reachable);
850 }
851
852 static uint32_t count_object_type(struct bitmap_index *bitmap_git,
853 enum object_type type)
854 {
855 struct bitmap *objects = bitmap_git->result;
856 struct eindex *eindex = &bitmap_git->ext_index;
857
858 uint32_t i = 0, count = 0;
859 struct ewah_iterator it;
860 eword_t filter;
861
862 switch (type) {
863 case OBJ_COMMIT:
864 ewah_iterator_init(&it, bitmap_git->commits);
865 break;
866
867 case OBJ_TREE:
868 ewah_iterator_init(&it, bitmap_git->trees);
869 break;
870
871 case OBJ_BLOB:
872 ewah_iterator_init(&it, bitmap_git->blobs);
873 break;
874
875 case OBJ_TAG:
876 ewah_iterator_init(&it, bitmap_git->tags);
877 break;
878
879 default:
880 return 0;
881 }
882
883 while (i < objects->word_alloc && ewah_iterator_next(&filter, &it)) {
884 eword_t word = objects->words[i++] & filter;
885 count += ewah_bit_popcount64(word);
886 }
887
888 for (i = 0; i < eindex->count; ++i) {
889 if (eindex->objects[i]->type == type &&
890 bitmap_get(objects, bitmap_git->pack->num_objects + i))
891 count++;
892 }
893
894 return count;
895 }
896
897 void count_bitmap_commit_list(struct bitmap_index *bitmap_git,
898 uint32_t *commits, uint32_t *trees,
899 uint32_t *blobs, uint32_t *tags)
900 {
901 assert(bitmap_git->result);
902
903 if (commits)
904 *commits = count_object_type(bitmap_git, OBJ_COMMIT);
905
906 if (trees)
907 *trees = count_object_type(bitmap_git, OBJ_TREE);
908
909 if (blobs)
910 *blobs = count_object_type(bitmap_git, OBJ_BLOB);
911
912 if (tags)
913 *tags = count_object_type(bitmap_git, OBJ_TAG);
914 }
915
916 struct bitmap_test_data {
917 struct bitmap_index *bitmap_git;
918 struct bitmap *base;
919 struct progress *prg;
920 size_t seen;
921 };
922
923 static void test_show_object(struct object *object, const char *name,
924 void *data)
925 {
926 struct bitmap_test_data *tdata = data;
927 int bitmap_pos;
928
929 bitmap_pos = bitmap_position(tdata->bitmap_git, &object->oid);
930 if (bitmap_pos < 0)
931 die("Object not in bitmap: %s\n", oid_to_hex(&object->oid));
932
933 bitmap_set(tdata->base, bitmap_pos);
934 display_progress(tdata->prg, ++tdata->seen);
935 }
936
937 static void test_show_commit(struct commit *commit, void *data)
938 {
939 struct bitmap_test_data *tdata = data;
940 int bitmap_pos;
941
942 bitmap_pos = bitmap_position(tdata->bitmap_git,
943 &commit->object.oid);
944 if (bitmap_pos < 0)
945 die("Object not in bitmap: %s\n", oid_to_hex(&commit->object.oid));
946
947 bitmap_set(tdata->base, bitmap_pos);
948 display_progress(tdata->prg, ++tdata->seen);
949 }
950
951 void test_bitmap_walk(struct rev_info *revs)
952 {
953 struct object *root;
954 struct bitmap *result = NULL;
955 khiter_t pos;
956 size_t result_popcnt;
957 struct bitmap_test_data tdata;
958 struct bitmap_index *bitmap_git;
959
960 if (!(bitmap_git = prepare_bitmap_git(revs->repo)))
961 die("failed to load bitmap indexes");
962
963 if (revs->pending.nr != 1)
964 die("you must specify exactly one commit to test");
965
966 fprintf(stderr, "Bitmap v%d test (%d entries loaded)\n",
967 bitmap_git->version, bitmap_git->entry_count);
968
969 root = revs->pending.objects[0].item;
970 pos = kh_get_oid_map(bitmap_git->bitmaps, root->oid);
971
972 if (pos < kh_end(bitmap_git->bitmaps)) {
973 struct stored_bitmap *st = kh_value(bitmap_git->bitmaps, pos);
974 struct ewah_bitmap *bm = lookup_stored_bitmap(st);
975
976 fprintf(stderr, "Found bitmap for %s. %d bits / %08x checksum\n",
977 oid_to_hex(&root->oid), (int)bm->bit_size, ewah_checksum(bm));
978
979 result = ewah_to_bitmap(bm);
980 }
981
982 if (result == NULL)
983 die("Commit %s doesn't have an indexed bitmap", oid_to_hex(&root->oid));
984
985 revs->tag_objects = 1;
986 revs->tree_objects = 1;
987 revs->blob_objects = 1;
988
989 result_popcnt = bitmap_popcount(result);
990
991 if (prepare_revision_walk(revs))
992 die("revision walk setup failed");
993
994 tdata.bitmap_git = bitmap_git;
995 tdata.base = bitmap_new();
996 tdata.prg = start_progress("Verifying bitmap entries", result_popcnt);
997 tdata.seen = 0;
998
999 traverse_commit_list(revs, &test_show_commit, &test_show_object, &tdata);
1000
1001 stop_progress(&tdata.prg);
1002
1003 if (bitmap_equals(result, tdata.base))
1004 fprintf(stderr, "OK!\n");
1005 else
1006 fprintf(stderr, "Mismatch!\n");
1007
1008 free_bitmap_index(bitmap_git);
1009 }
1010
1011 static int rebuild_bitmap(uint32_t *reposition,
1012 struct ewah_bitmap *source,
1013 struct bitmap *dest)
1014 {
1015 uint32_t pos = 0;
1016 struct ewah_iterator it;
1017 eword_t word;
1018
1019 ewah_iterator_init(&it, source);
1020
1021 while (ewah_iterator_next(&word, &it)) {
1022 uint32_t offset, bit_pos;
1023
1024 for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
1025 if ((word >> offset) == 0)
1026 break;
1027
1028 offset += ewah_bit_ctz64(word >> offset);
1029
1030 bit_pos = reposition[pos + offset];
1031 if (bit_pos > 0)
1032 bitmap_set(dest, bit_pos - 1);
1033 else /* can't reuse, we don't have the object */
1034 return -1;
1035 }
1036
1037 pos += BITS_IN_EWORD;
1038 }
1039 return 0;
1040 }
1041
1042 int rebuild_existing_bitmaps(struct bitmap_index *bitmap_git,
1043 struct packing_data *mapping,
1044 khash_sha1 *reused_bitmaps,
1045 int show_progress)
1046 {
1047 uint32_t i, num_objects;
1048 uint32_t *reposition;
1049 struct bitmap *rebuild;
1050 struct stored_bitmap *stored;
1051 struct progress *progress = NULL;
1052
1053 khiter_t hash_pos;
1054 int hash_ret;
1055
1056 num_objects = bitmap_git->pack->num_objects;
1057 reposition = xcalloc(num_objects, sizeof(uint32_t));
1058
1059 for (i = 0; i < num_objects; ++i) {
1060 const unsigned char *sha1;
1061 struct revindex_entry *entry;
1062 struct object_entry *oe;
1063
1064 entry = &bitmap_git->pack->revindex[i];
1065 sha1 = nth_packed_object_sha1(bitmap_git->pack, entry->nr);
1066 oe = packlist_find(mapping, sha1, NULL);
1067
1068 if (oe)
1069 reposition[i] = oe_in_pack_pos(mapping, oe) + 1;
1070 }
1071
1072 rebuild = bitmap_new();
1073 i = 0;
1074
1075 if (show_progress)
1076 progress = start_progress("Reusing bitmaps", 0);
1077
1078 kh_foreach_value(bitmap_git->bitmaps, stored, {
1079 if (stored->flags & BITMAP_FLAG_REUSE) {
1080 if (!rebuild_bitmap(reposition,
1081 lookup_stored_bitmap(stored),
1082 rebuild)) {
1083 hash_pos = kh_put_sha1(reused_bitmaps,
1084 stored->oid.hash,
1085 &hash_ret);
1086 kh_value(reused_bitmaps, hash_pos) =
1087 bitmap_to_ewah(rebuild);
1088 }
1089 bitmap_reset(rebuild);
1090 display_progress(progress, ++i);
1091 }
1092 });
1093
1094 stop_progress(&progress);
1095
1096 free(reposition);
1097 bitmap_free(rebuild);
1098 return 0;
1099 }
1100
1101 void free_bitmap_index(struct bitmap_index *b)
1102 {
1103 if (!b)
1104 return;
1105
1106 if (b->map)
1107 munmap(b->map, b->map_size);
1108 ewah_pool_free(b->commits);
1109 ewah_pool_free(b->trees);
1110 ewah_pool_free(b->blobs);
1111 ewah_pool_free(b->tags);
1112 kh_destroy_oid_map(b->bitmaps);
1113 free(b->ext_index.objects);
1114 free(b->ext_index.hashes);
1115 bitmap_free(b->result);
1116 bitmap_free(b->haves);
1117 free(b);
1118 }
1119
1120 int bitmap_has_oid_in_uninteresting(struct bitmap_index *bitmap_git,
1121 const struct object_id *oid)
1122 {
1123 int pos;
1124
1125 if (!bitmap_git)
1126 return 0; /* no bitmap loaded */
1127 if (!bitmap_git->haves)
1128 return 0; /* walk had no "haves" */
1129
1130 pos = bitmap_position_packfile(bitmap_git, oid);
1131 if (pos < 0)
1132 return 0;
1133
1134 return bitmap_get(bitmap_git->haves, pos);
1135 }