pack-bitmap: remove bitmap_git global variable
[git/git.git] / pack-bitmap.c
CommitLineData
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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"
0317f455 12#include "packfile.h"
a80d72db
SB
13#include "repository.h"
14#include "object-store.h"
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15
16/*
17 * An entry on the bitmap index, representing the bitmap for a given
18 * commit.
19 */
20struct stored_bitmap {
21 unsigned char sha1[20];
22 struct ewah_bitmap *root;
23 struct stored_bitmap *xor;
24 int flags;
25};
26
27/*
3ae5fa07 28 * The active bitmap index for a repository. By design, repositories only have
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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 */
3ae5fa07 35struct bitmap_index {
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36 /* Packfile to which this bitmap index belongs to */
37 struct packed_git *pack;
38
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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
25143a54 63 /* Map from SHA1 -> `stored_bitmap` for all the bitmapped commits */
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64 khash_sha1 *bitmaps;
65
66 /* Number of bitmapped commits */
67 uint32_t entry_count;
68
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69 /* Name-hash cache (or NULL if not present). */
70 uint32_t *hashes;
71
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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;
3ae5fa07 93};
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94
95static struct ewah_bitmap *lookup_stored_bitmap(struct stored_bitmap *st)
96{
97 struct ewah_bitmap *parent;
98 struct ewah_bitmap *composed;
99
100 if (st->xor == NULL)
101 return st->root;
102
103 composed = ewah_pool_new();
104 parent = lookup_stored_bitmap(st->xor);
105 ewah_xor(st->root, parent, composed);
106
107 ewah_pool_free(st->root);
108 st->root = composed;
109 st->xor = NULL;
110
111 return composed;
112}
113
114/*
115 * Read a bitmap from the current read position on the mmaped
116 * index, and increase the read position accordingly
117 */
118static struct ewah_bitmap *read_bitmap_1(struct bitmap_index *index)
119{
120 struct ewah_bitmap *b = ewah_pool_new();
121
1140bf01 122 ssize_t bitmap_size = ewah_read_mmap(b,
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123 index->map + index->map_pos,
124 index->map_size - index->map_pos);
125
126 if (bitmap_size < 0) {
127 error("Failed to load bitmap index (corrupted?)");
128 ewah_pool_free(b);
129 return NULL;
130 }
131
132 index->map_pos += bitmap_size;
133 return b;
134}
135
136static int load_bitmap_header(struct bitmap_index *index)
137{
138 struct bitmap_disk_header *header = (void *)index->map;
139
140 if (index->map_size < sizeof(*header) + 20)
141 return error("Corrupted bitmap index (missing header data)");
142
143 if (memcmp(header->magic, BITMAP_IDX_SIGNATURE, sizeof(BITMAP_IDX_SIGNATURE)) != 0)
144 return error("Corrupted bitmap index file (wrong header)");
145
146 index->version = ntohs(header->version);
147 if (index->version != 1)
148 return error("Unsupported version for bitmap index file (%d)", index->version);
149
150 /* Parse known bitmap format options */
151 {
152 uint32_t flags = ntohs(header->options);
153
154 if ((flags & BITMAP_OPT_FULL_DAG) == 0)
155 return error("Unsupported options for bitmap index file "
156 "(Git requires BITMAP_OPT_FULL_DAG)");
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157
158 if (flags & BITMAP_OPT_HASH_CACHE) {
159 unsigned char *end = index->map + index->map_size - 20;
160 index->hashes = ((uint32_t *)end) - index->pack->num_objects;
161 }
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162 }
163
164 index->entry_count = ntohl(header->entry_count);
165 index->map_pos += sizeof(*header);
166 return 0;
167}
168
169static struct stored_bitmap *store_bitmap(struct bitmap_index *index,
170 struct ewah_bitmap *root,
171 const unsigned char *sha1,
172 struct stored_bitmap *xor_with,
173 int flags)
174{
175 struct stored_bitmap *stored;
176 khiter_t hash_pos;
177 int ret;
178
179 stored = xmalloc(sizeof(struct stored_bitmap));
180 stored->root = root;
181 stored->xor = xor_with;
182 stored->flags = flags;
183 hashcpy(stored->sha1, sha1);
184
185 hash_pos = kh_put_sha1(index->bitmaps, stored->sha1, &ret);
186
187 /* a 0 return code means the insertion succeeded with no changes,
188 * because the SHA1 already existed on the map. this is bad, there
189 * shouldn't be duplicated commits in the index */
190 if (ret == 0) {
191 error("Duplicate entry in bitmap index: %s", sha1_to_hex(sha1));
192 return NULL;
193 }
194
195 kh_value(index->bitmaps, hash_pos) = stored;
196 return stored;
197}
198
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KB
199static inline uint32_t read_be32(const unsigned char *buffer, size_t *pos)
200{
201 uint32_t result = get_be32(buffer + *pos);
202 (*pos) += sizeof(result);
203 return result;
204}
205
206static inline uint8_t read_u8(const unsigned char *buffer, size_t *pos)
207{
208 return buffer[(*pos)++];
209}
210
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211#define MAX_XOR_OFFSET 160
212
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213static int load_bitmap_entries_v1(struct bitmap_index *index)
214{
fff42755 215 uint32_t i;
599dc766 216 struct stored_bitmap *recent_bitmaps[MAX_XOR_OFFSET] = { NULL };
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217
218 for (i = 0; i < index->entry_count; ++i) {
219 int xor_offset, flags;
220 struct ewah_bitmap *bitmap = NULL;
221 struct stored_bitmap *xor_bitmap = NULL;
222 uint32_t commit_idx_pos;
223 const unsigned char *sha1;
224
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225 commit_idx_pos = read_be32(index->map, &index->map_pos);
226 xor_offset = read_u8(index->map, &index->map_pos);
227 flags = read_u8(index->map, &index->map_pos);
fff42755 228
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229 sha1 = nth_packed_object_sha1(index->pack, commit_idx_pos);
230
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231 bitmap = read_bitmap_1(index);
232 if (!bitmap)
233 return -1;
234
235 if (xor_offset > MAX_XOR_OFFSET || xor_offset > i)
236 return error("Corrupted bitmap pack index");
237
238 if (xor_offset > 0) {
239 xor_bitmap = recent_bitmaps[(i - xor_offset) % MAX_XOR_OFFSET];
240
241 if (xor_bitmap == NULL)
242 return error("Invalid XOR offset in bitmap pack index");
243 }
244
245 recent_bitmaps[i % MAX_XOR_OFFSET] = store_bitmap(
246 index, bitmap, sha1, xor_bitmap, flags);
247 }
248
249 return 0;
250}
251
cb468050
JH
252static char *pack_bitmap_filename(struct packed_git *p)
253{
9ae97018 254 size_t len;
cb468050 255
9ae97018 256 if (!strip_suffix(p->pack_name, ".pack", &len))
033abf97 257 BUG("pack_name does not end in .pack");
9ae97018 258 return xstrfmt("%.*s.bitmap", (int)len, p->pack_name);
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259}
260
3ae5fa07 261static int open_pack_bitmap_1(struct bitmap_index *bitmap_git, struct packed_git *packfile)
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262{
263 int fd;
264 struct stat st;
265 char *idx_name;
266
267 if (open_pack_index(packfile))
268 return -1;
269
270 idx_name = pack_bitmap_filename(packfile);
a5436b57 271 fd = git_open(idx_name);
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272 free(idx_name);
273
274 if (fd < 0)
275 return -1;
276
277 if (fstat(fd, &st)) {
278 close(fd);
279 return -1;
280 }
281
3ae5fa07 282 if (bitmap_git->pack) {
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283 warning("ignoring extra bitmap file: %s", packfile->pack_name);
284 close(fd);
285 return -1;
286 }
287
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288 bitmap_git->pack = packfile;
289 bitmap_git->map_size = xsize_t(st.st_size);
290 bitmap_git->map = xmmap(NULL, bitmap_git->map_size, PROT_READ, MAP_PRIVATE, fd, 0);
291 bitmap_git->map_pos = 0;
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292 close(fd);
293
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294 if (load_bitmap_header(bitmap_git) < 0) {
295 munmap(bitmap_git->map, bitmap_git->map_size);
296 bitmap_git->map = NULL;
297 bitmap_git->map_size = 0;
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298 return -1;
299 }
300
301 return 0;
302}
303
3ae5fa07 304static int load_pack_bitmap(struct bitmap_index *bitmap_git)
fff42755 305{
3ae5fa07 306 assert(bitmap_git->map && !bitmap_git->loaded);
fff42755 307
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JT
308 bitmap_git->bitmaps = kh_init_sha1();
309 bitmap_git->ext_index.positions = kh_init_sha1_pos();
310 load_pack_revindex(bitmap_git->pack);
fff42755 311
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JT
312 if (!(bitmap_git->commits = read_bitmap_1(bitmap_git)) ||
313 !(bitmap_git->trees = read_bitmap_1(bitmap_git)) ||
314 !(bitmap_git->blobs = read_bitmap_1(bitmap_git)) ||
315 !(bitmap_git->tags = read_bitmap_1(bitmap_git)))
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316 goto failed;
317
3ae5fa07 318 if (load_bitmap_entries_v1(bitmap_git) < 0)
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319 goto failed;
320
3ae5fa07 321 bitmap_git->loaded = 1;
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322 return 0;
323
324failed:
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JT
325 munmap(bitmap_git->map, bitmap_git->map_size);
326 bitmap_git->map = NULL;
327 bitmap_git->map_size = 0;
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328 return -1;
329}
330
3ae5fa07 331static int open_pack_bitmap(struct bitmap_index *bitmap_git)
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332{
333 struct packed_git *p;
334 int ret = -1;
335
3ae5fa07 336 assert(!bitmap_git->map && !bitmap_git->loaded);
fff42755 337
a80d72db 338 for (p = get_packed_git(the_repository); p; p = p->next) {
3ae5fa07 339 if (open_pack_bitmap_1(bitmap_git, p) == 0)
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340 ret = 0;
341 }
342
343 return ret;
344}
345
3ae5fa07 346struct bitmap_index *prepare_bitmap_git(void)
fff42755 347{
3ae5fa07 348 struct bitmap_index *bitmap_git = xcalloc(1, sizeof(*bitmap_git));
fff42755 349
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JT
350 if (!open_pack_bitmap(bitmap_git) && !load_pack_bitmap(bitmap_git))
351 return bitmap_git;
fff42755 352
3ae5fa07 353 return NULL;
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354}
355
356struct include_data {
3ae5fa07 357 struct bitmap_index *bitmap_git;
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358 struct bitmap *base;
359 struct bitmap *seen;
360};
361
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JT
362static inline int bitmap_position_extended(struct bitmap_index *bitmap_git,
363 const unsigned char *sha1)
fff42755 364{
3ae5fa07 365 khash_sha1_pos *positions = bitmap_git->ext_index.positions;
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366 khiter_t pos = kh_get_sha1_pos(positions, sha1);
367
368 if (pos < kh_end(positions)) {
369 int bitmap_pos = kh_value(positions, pos);
3ae5fa07 370 return bitmap_pos + bitmap_git->pack->num_objects;
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371 }
372
373 return -1;
374}
375
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JT
376static inline int bitmap_position_packfile(struct bitmap_index *bitmap_git,
377 const unsigned char *sha1)
fff42755 378{
3ae5fa07 379 off_t offset = find_pack_entry_one(sha1, bitmap_git->pack);
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380 if (!offset)
381 return -1;
382
3ae5fa07 383 return find_revindex_position(bitmap_git->pack, offset);
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384}
385
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JT
386static int bitmap_position(struct bitmap_index *bitmap_git,
387 const unsigned char *sha1)
fff42755 388{
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JT
389 int pos = bitmap_position_packfile(bitmap_git, sha1);
390 return (pos >= 0) ? pos : bitmap_position_extended(bitmap_git, sha1);
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391}
392
3ae5fa07
JT
393static int ext_index_add_object(struct bitmap_index *bitmap_git,
394 struct object *object, const char *name)
fff42755 395{
3ae5fa07 396 struct eindex *eindex = &bitmap_git->ext_index;
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397
398 khiter_t hash_pos;
399 int hash_ret;
400 int bitmap_pos;
401
ed1c9977 402 hash_pos = kh_put_sha1_pos(eindex->positions, object->oid.hash, &hash_ret);
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403 if (hash_ret > 0) {
404 if (eindex->count >= eindex->alloc) {
405 eindex->alloc = (eindex->alloc + 16) * 3 / 2;
2756ca43
RS
406 REALLOC_ARRAY(eindex->objects, eindex->alloc);
407 REALLOC_ARRAY(eindex->hashes, eindex->alloc);
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VM
408 }
409
410 bitmap_pos = eindex->count;
411 eindex->objects[eindex->count] = object;
412 eindex->hashes[eindex->count] = pack_name_hash(name);
413 kh_value(eindex->positions, hash_pos) = bitmap_pos;
414 eindex->count++;
415 } else {
416 bitmap_pos = kh_value(eindex->positions, hash_pos);
417 }
418
3ae5fa07 419 return bitmap_pos + bitmap_git->pack->num_objects;
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420}
421
3ae5fa07
JT
422struct bitmap_show_data {
423 struct bitmap_index *bitmap_git;
424 struct bitmap *base;
425};
426
427static void show_object(struct object *object, const char *name, void *data_)
fff42755 428{
3ae5fa07 429 struct bitmap_show_data *data = data_;
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VM
430 int bitmap_pos;
431
3ae5fa07 432 bitmap_pos = bitmap_position(data->bitmap_git, object->oid.hash);
fff42755 433
de1e67d0 434 if (bitmap_pos < 0)
3ae5fa07
JT
435 bitmap_pos = ext_index_add_object(data->bitmap_git, object,
436 name);
fff42755 437
3ae5fa07 438 bitmap_set(data->base, bitmap_pos);
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VM
439}
440
441static void show_commit(struct commit *commit, void *data)
442{
443}
444
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JT
445static int add_to_include_set(struct bitmap_index *bitmap_git,
446 struct include_data *data,
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VM
447 const unsigned char *sha1,
448 int bitmap_pos)
449{
450 khiter_t hash_pos;
451
452 if (data->seen && bitmap_get(data->seen, bitmap_pos))
453 return 0;
454
455 if (bitmap_get(data->base, bitmap_pos))
456 return 0;
457
3ae5fa07
JT
458 hash_pos = kh_get_sha1(bitmap_git->bitmaps, sha1);
459 if (hash_pos < kh_end(bitmap_git->bitmaps)) {
460 struct stored_bitmap *st = kh_value(bitmap_git->bitmaps, hash_pos);
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461 bitmap_or_ewah(data->base, lookup_stored_bitmap(st));
462 return 0;
463 }
464
465 bitmap_set(data->base, bitmap_pos);
466 return 1;
467}
468
469static int should_include(struct commit *commit, void *_data)
470{
471 struct include_data *data = _data;
472 int bitmap_pos;
473
3ae5fa07 474 bitmap_pos = bitmap_position(data->bitmap_git, commit->object.oid.hash);
fff42755 475 if (bitmap_pos < 0)
3ae5fa07
JT
476 bitmap_pos = ext_index_add_object(data->bitmap_git,
477 (struct object *)commit,
478 NULL);
fff42755 479
3ae5fa07
JT
480 if (!add_to_include_set(data->bitmap_git, data, commit->object.oid.hash,
481 bitmap_pos)) {
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482 struct commit_list *parent = commit->parents;
483
484 while (parent) {
485 parent->item->object.flags |= SEEN;
486 parent = parent->next;
487 }
488
489 return 0;
490 }
491
492 return 1;
493}
494
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JT
495static struct bitmap *find_objects(struct bitmap_index *bitmap_git,
496 struct rev_info *revs,
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VM
497 struct object_list *roots,
498 struct bitmap *seen)
499{
500 struct bitmap *base = NULL;
501 int needs_walk = 0;
502
503 struct object_list *not_mapped = NULL;
504
505 /*
506 * Go through all the roots for the walk. The ones that have bitmaps
507 * on the bitmap index will be `or`ed together to form an initial
508 * global reachability analysis.
509 *
510 * The ones without bitmaps in the index will be stored in the
511 * `not_mapped_list` for further processing.
512 */
513 while (roots) {
514 struct object *object = roots->item;
515 roots = roots->next;
516
517 if (object->type == OBJ_COMMIT) {
3ae5fa07 518 khiter_t pos = kh_get_sha1(bitmap_git->bitmaps, object->oid.hash);
fff42755 519
3ae5fa07
JT
520 if (pos < kh_end(bitmap_git->bitmaps)) {
521 struct stored_bitmap *st = kh_value(bitmap_git->bitmaps, pos);
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522 struct ewah_bitmap *or_with = lookup_stored_bitmap(st);
523
524 if (base == NULL)
525 base = ewah_to_bitmap(or_with);
526 else
527 bitmap_or_ewah(base, or_with);
528
529 object->flags |= SEEN;
530 continue;
531 }
532 }
533
534 object_list_insert(object, &not_mapped);
535 }
536
537 /*
538 * Best case scenario: We found bitmaps for all the roots,
539 * so the resulting `or` bitmap has the full reachability analysis
540 */
541 if (not_mapped == NULL)
542 return base;
543
544 roots = not_mapped;
545
546 /*
547 * Let's iterate through all the roots that don't have bitmaps to
548 * check if we can determine them to be reachable from the existing
549 * global bitmap.
550 *
551 * If we cannot find them in the existing global bitmap, we'll need
552 * to push them to an actual walk and run it until we can confirm
553 * they are reachable
554 */
555 while (roots) {
556 struct object *object = roots->item;
557 int pos;
558
559 roots = roots->next;
3ae5fa07 560 pos = bitmap_position(bitmap_git, object->oid.hash);
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561
562 if (pos < 0 || base == NULL || !bitmap_get(base, pos)) {
563 object->flags &= ~UNINTERESTING;
564 add_pending_object(revs, object, "");
565 needs_walk = 1;
566 } else {
567 object->flags |= SEEN;
568 }
569 }
570
571 if (needs_walk) {
572 struct include_data incdata;
3ae5fa07 573 struct bitmap_show_data show_data;
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574
575 if (base == NULL)
576 base = bitmap_new();
577
3ae5fa07 578 incdata.bitmap_git = bitmap_git;
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579 incdata.base = base;
580 incdata.seen = seen;
581
582 revs->include_check = should_include;
583 revs->include_check_data = &incdata;
584
585 if (prepare_revision_walk(revs))
586 die("revision walk setup failed");
587
3ae5fa07
JT
588 show_data.bitmap_git = bitmap_git;
589 show_data.base = base;
590
591 traverse_commit_list(revs, show_commit, show_object,
592 &show_data);
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VM
593 }
594
595 return base;
596}
597
3ae5fa07 598static void show_extended_objects(struct bitmap_index *bitmap_git,
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VM
599 show_reachable_fn show_reach)
600{
3ae5fa07
JT
601 struct bitmap *objects = bitmap_git->result;
602 struct eindex *eindex = &bitmap_git->ext_index;
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VM
603 uint32_t i;
604
605 for (i = 0; i < eindex->count; ++i) {
606 struct object *obj;
607
3ae5fa07 608 if (!bitmap_get(objects, bitmap_git->pack->num_objects + i))
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VM
609 continue;
610
611 obj = eindex->objects[i];
20664967 612 show_reach(&obj->oid, obj->type, 0, eindex->hashes[i], NULL, 0);
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613 }
614}
615
616static void show_objects_for_type(
3ae5fa07 617 struct bitmap_index *bitmap_git,
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618 struct ewah_bitmap *type_filter,
619 enum object_type object_type,
620 show_reachable_fn show_reach)
621{
622 size_t pos = 0, i = 0;
623 uint32_t offset;
624
625 struct ewah_iterator it;
626 eword_t filter;
627
3ae5fa07
JT
628 struct bitmap *objects = bitmap_git->result;
629
630 if (bitmap_git->reuse_objects == bitmap_git->pack->num_objects)
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VM
631 return;
632
633 ewah_iterator_init(&it, type_filter);
634
635 while (i < objects->word_alloc && ewah_iterator_next(&filter, &it)) {
636 eword_t word = objects->words[i] & filter;
637
34b935c0 638 for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
20664967 639 struct object_id oid;
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VM
640 struct revindex_entry *entry;
641 uint32_t hash = 0;
642
643 if ((word >> offset) == 0)
644 break;
645
646 offset += ewah_bit_ctz64(word >> offset);
647
3ae5fa07 648 if (pos + offset < bitmap_git->reuse_objects)
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VM
649 continue;
650
3ae5fa07
JT
651 entry = &bitmap_git->pack->revindex[pos + offset];
652 nth_packed_object_oid(&oid, bitmap_git->pack, entry->nr);
fff42755 653
3ae5fa07
JT
654 if (bitmap_git->hashes)
655 hash = get_be32(bitmap_git->hashes + entry->nr);
ae4f07fb 656
3ae5fa07 657 show_reach(&oid, object_type, 0, hash, bitmap_git->pack, entry->offset);
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VM
658 }
659
34b935c0 660 pos += BITS_IN_EWORD;
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VM
661 i++;
662 }
663}
664
3ae5fa07
JT
665static int in_bitmapped_pack(struct bitmap_index *bitmap_git,
666 struct object_list *roots)
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VM
667{
668 while (roots) {
669 struct object *object = roots->item;
670 roots = roots->next;
671
3ae5fa07 672 if (find_pack_entry_one(object->oid.hash, bitmap_git->pack) > 0)
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VM
673 return 1;
674 }
675
676 return 0;
677}
678
3ae5fa07 679struct bitmap_index *prepare_bitmap_walk(struct rev_info *revs)
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VM
680{
681 unsigned int i;
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VM
682
683 struct object_list *wants = NULL;
684 struct object_list *haves = NULL;
685
686 struct bitmap *wants_bitmap = NULL;
687 struct bitmap *haves_bitmap = NULL;
688
3ae5fa07
JT
689 struct bitmap_index *bitmap_git = xcalloc(1, sizeof(*bitmap_git));
690 /* try to open a bitmapped pack, but don't parse it yet
691 * because we may not need to use it */
692 if (open_pack_bitmap(bitmap_git) < 0)
693 return NULL;
fff42755 694
4d01a7fa
695 for (i = 0; i < revs->pending.nr; ++i) {
696 struct object *object = revs->pending.objects[i].item;
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697
698 if (object->type == OBJ_NONE)
c251c83d 699 parse_object_or_die(&object->oid, NULL);
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700
701 while (object->type == OBJ_TAG) {
702 struct tag *tag = (struct tag *) object;
703
704 if (object->flags & UNINTERESTING)
705 object_list_insert(object, &haves);
706 else
707 object_list_insert(object, &wants);
708
709 if (!tag->tagged)
710 die("bad tag");
c251c83d 711 object = parse_object_or_die(&tag->tagged->oid, NULL);
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712 }
713
714 if (object->flags & UNINTERESTING)
715 object_list_insert(object, &haves);
716 else
717 object_list_insert(object, &wants);
718 }
719
720 /*
721 * if we have a HAVES list, but none of those haves is contained
722 * in the packfile that has a bitmap, we don't have anything to
723 * optimize here
724 */
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725 if (haves && !in_bitmapped_pack(bitmap_git, haves))
726 return NULL;
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727
728 /* if we don't want anything, we're done here */
729 if (!wants)
3ae5fa07 730 return NULL;
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731
732 /*
733 * now we're going to use bitmaps, so load the actual bitmap entries
734 * from disk. this is the point of no return; after this the rev_list
735 * becomes invalidated and we must perform the revwalk through bitmaps
736 */
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JT
737 if (!bitmap_git->loaded && load_pack_bitmap(bitmap_git) < 0)
738 return NULL;
fff42755 739
4d01a7fa 740 object_array_clear(&revs->pending);
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VM
741
742 if (haves) {
2db1a43f 743 revs->ignore_missing_links = 1;
3ae5fa07 744 haves_bitmap = find_objects(bitmap_git, revs, haves, NULL);
fff42755 745 reset_revision_walk();
2db1a43f 746 revs->ignore_missing_links = 0;
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747
748 if (haves_bitmap == NULL)
033abf97 749 BUG("failed to perform bitmap walk");
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750 }
751
3ae5fa07 752 wants_bitmap = find_objects(bitmap_git, revs, wants, haves_bitmap);
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753
754 if (!wants_bitmap)
033abf97 755 BUG("failed to perform bitmap walk");
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756
757 if (haves_bitmap)
758 bitmap_and_not(wants_bitmap, haves_bitmap);
759
3ae5fa07 760 bitmap_git->result = wants_bitmap;
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761
762 bitmap_free(haves_bitmap);
3ae5fa07 763 return bitmap_git;
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764}
765
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766int reuse_partial_packfile_from_bitmap(struct bitmap_index *bitmap_git,
767 struct packed_git **packfile,
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768 uint32_t *entries,
769 off_t *up_to)
770{
771 /*
772 * Reuse the packfile content if we need more than
773 * 90% of its objects
774 */
775 static const double REUSE_PERCENT = 0.9;
776
3ae5fa07 777 struct bitmap *result = bitmap_git->result;
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778 uint32_t reuse_threshold;
779 uint32_t i, reuse_objects = 0;
780
781 assert(result);
782
783 for (i = 0; i < result->word_alloc; ++i) {
784 if (result->words[i] != (eword_t)~0) {
785 reuse_objects += ewah_bit_ctz64(~result->words[i]);
786 break;
787 }
788
34b935c0 789 reuse_objects += BITS_IN_EWORD;
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790 }
791
792#ifdef GIT_BITMAP_DEBUG
793 {
794 const unsigned char *sha1;
795 struct revindex_entry *entry;
796
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797 entry = &bitmap_git->reverse_index->revindex[reuse_objects];
798 sha1 = nth_packed_object_sha1(bitmap_git->pack, entry->nr);
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VM
799
800 fprintf(stderr, "Failed to reuse at %d (%016llx)\n",
801 reuse_objects, result->words[i]);
802 fprintf(stderr, " %s\n", sha1_to_hex(sha1));
803 }
804#endif
805
806 if (!reuse_objects)
807 return -1;
808
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809 if (reuse_objects >= bitmap_git->pack->num_objects) {
810 bitmap_git->reuse_objects = *entries = bitmap_git->pack->num_objects;
fff42755 811 *up_to = -1; /* reuse the full pack */
3ae5fa07 812 *packfile = bitmap_git->pack;
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VM
813 return 0;
814 }
815
3ae5fa07 816 reuse_threshold = bitmap_popcount(bitmap_git->result) * REUSE_PERCENT;
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VM
817
818 if (reuse_objects < reuse_threshold)
819 return -1;
820
3ae5fa07
JT
821 bitmap_git->reuse_objects = *entries = reuse_objects;
822 *up_to = bitmap_git->pack->revindex[reuse_objects].offset;
823 *packfile = bitmap_git->pack;
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VM
824
825 return 0;
826}
827
3ae5fa07
JT
828void traverse_bitmap_commit_list(struct bitmap_index *bitmap_git,
829 show_reachable_fn show_reachable)
fff42755 830{
3ae5fa07 831 assert(bitmap_git->result);
fff42755 832
3ae5fa07 833 show_objects_for_type(bitmap_git, bitmap_git->commits,
fff42755 834 OBJ_COMMIT, show_reachable);
3ae5fa07 835 show_objects_for_type(bitmap_git, bitmap_git->trees,
fff42755 836 OBJ_TREE, show_reachable);
3ae5fa07 837 show_objects_for_type(bitmap_git, bitmap_git->blobs,
fff42755 838 OBJ_BLOB, show_reachable);
3ae5fa07 839 show_objects_for_type(bitmap_git, bitmap_git->tags,
fff42755
VM
840 OBJ_TAG, show_reachable);
841
3ae5fa07 842 show_extended_objects(bitmap_git, show_reachable);
fff42755 843
3ae5fa07
JT
844 bitmap_free(bitmap_git->result);
845 bitmap_git->result = NULL;
fff42755
VM
846}
847
3ae5fa07 848static uint32_t count_object_type(struct bitmap_index *bitmap_git,
fff42755
VM
849 enum object_type type)
850{
3ae5fa07
JT
851 struct bitmap *objects = bitmap_git->result;
852 struct eindex *eindex = &bitmap_git->ext_index;
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VM
853
854 uint32_t i = 0, count = 0;
855 struct ewah_iterator it;
856 eword_t filter;
857
858 switch (type) {
859 case OBJ_COMMIT:
3ae5fa07 860 ewah_iterator_init(&it, bitmap_git->commits);
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VM
861 break;
862
863 case OBJ_TREE:
3ae5fa07 864 ewah_iterator_init(&it, bitmap_git->trees);
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VM
865 break;
866
867 case OBJ_BLOB:
3ae5fa07 868 ewah_iterator_init(&it, bitmap_git->blobs);
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VM
869 break;
870
871 case OBJ_TAG:
3ae5fa07 872 ewah_iterator_init(&it, bitmap_git->tags);
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VM
873 break;
874
875 default:
876 return 0;
877 }
878
879 while (i < objects->word_alloc && ewah_iterator_next(&filter, &it)) {
880 eword_t word = objects->words[i++] & filter;
881 count += ewah_bit_popcount64(word);
882 }
883
884 for (i = 0; i < eindex->count; ++i) {
885 if (eindex->objects[i]->type == type &&
3ae5fa07 886 bitmap_get(objects, bitmap_git->pack->num_objects + i))
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VM
887 count++;
888 }
889
890 return count;
891}
892
3ae5fa07
JT
893void count_bitmap_commit_list(struct bitmap_index *bitmap_git,
894 uint32_t *commits, uint32_t *trees,
fff42755
VM
895 uint32_t *blobs, uint32_t *tags)
896{
3ae5fa07 897 assert(bitmap_git->result);
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VM
898
899 if (commits)
3ae5fa07 900 *commits = count_object_type(bitmap_git, OBJ_COMMIT);
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VM
901
902 if (trees)
3ae5fa07 903 *trees = count_object_type(bitmap_git, OBJ_TREE);
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VM
904
905 if (blobs)
3ae5fa07 906 *blobs = count_object_type(bitmap_git, OBJ_BLOB);
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VM
907
908 if (tags)
3ae5fa07 909 *tags = count_object_type(bitmap_git, OBJ_TAG);
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VM
910}
911
912struct bitmap_test_data {
3ae5fa07 913 struct bitmap_index *bitmap_git;
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VM
914 struct bitmap *base;
915 struct progress *prg;
916 size_t seen;
917};
918
de1e67d0
JK
919static void test_show_object(struct object *object, const char *name,
920 void *data)
fff42755
VM
921{
922 struct bitmap_test_data *tdata = data;
923 int bitmap_pos;
924
3ae5fa07 925 bitmap_pos = bitmap_position(tdata->bitmap_git, object->oid.hash);
fff42755 926 if (bitmap_pos < 0)
f2fd0760 927 die("Object not in bitmap: %s\n", oid_to_hex(&object->oid));
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VM
928
929 bitmap_set(tdata->base, bitmap_pos);
930 display_progress(tdata->prg, ++tdata->seen);
931}
932
933static void test_show_commit(struct commit *commit, void *data)
934{
935 struct bitmap_test_data *tdata = data;
936 int bitmap_pos;
937
3ae5fa07
JT
938 bitmap_pos = bitmap_position(tdata->bitmap_git,
939 commit->object.oid.hash);
fff42755 940 if (bitmap_pos < 0)
f2fd0760 941 die("Object not in bitmap: %s\n", oid_to_hex(&commit->object.oid));
fff42755
VM
942
943 bitmap_set(tdata->base, bitmap_pos);
944 display_progress(tdata->prg, ++tdata->seen);
945}
946
947void test_bitmap_walk(struct rev_info *revs)
948{
949 struct object *root;
950 struct bitmap *result = NULL;
951 khiter_t pos;
952 size_t result_popcnt;
953 struct bitmap_test_data tdata;
3ae5fa07 954 struct bitmap_index *bitmap_git;
fff42755 955
3ae5fa07 956 if (!(bitmap_git = prepare_bitmap_git()))
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VM
957 die("failed to load bitmap indexes");
958
959 if (revs->pending.nr != 1)
960 die("you must specify exactly one commit to test");
961
962 fprintf(stderr, "Bitmap v%d test (%d entries loaded)\n",
3ae5fa07 963 bitmap_git->version, bitmap_git->entry_count);
fff42755
VM
964
965 root = revs->pending.objects[0].item;
3ae5fa07 966 pos = kh_get_sha1(bitmap_git->bitmaps, root->oid.hash);
fff42755 967
3ae5fa07
JT
968 if (pos < kh_end(bitmap_git->bitmaps)) {
969 struct stored_bitmap *st = kh_value(bitmap_git->bitmaps, pos);
fff42755
VM
970 struct ewah_bitmap *bm = lookup_stored_bitmap(st);
971
972 fprintf(stderr, "Found bitmap for %s. %d bits / %08x checksum\n",
f2fd0760 973 oid_to_hex(&root->oid), (int)bm->bit_size, ewah_checksum(bm));
fff42755
VM
974
975 result = ewah_to_bitmap(bm);
976 }
977
978 if (result == NULL)
f2fd0760 979 die("Commit %s doesn't have an indexed bitmap", oid_to_hex(&root->oid));
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VM
980
981 revs->tag_objects = 1;
982 revs->tree_objects = 1;
983 revs->blob_objects = 1;
984
985 result_popcnt = bitmap_popcount(result);
986
987 if (prepare_revision_walk(revs))
988 die("revision walk setup failed");
989
3ae5fa07 990 tdata.bitmap_git = bitmap_git;
fff42755
VM
991 tdata.base = bitmap_new();
992 tdata.prg = start_progress("Verifying bitmap entries", result_popcnt);
993 tdata.seen = 0;
994
995 traverse_commit_list(revs, &test_show_commit, &test_show_object, &tdata);
996
997 stop_progress(&tdata.prg);
998
999 if (bitmap_equals(result, tdata.base))
1000 fprintf(stderr, "OK!\n");
1001 else
1002 fprintf(stderr, "Mismatch!\n");
f86a3747 1003
d201a1ec 1004 bitmap_free(result);
fff42755 1005}
7cc8f971
VM
1006
1007static int rebuild_bitmap(uint32_t *reposition,
1008 struct ewah_bitmap *source,
1009 struct bitmap *dest)
1010{
1011 uint32_t pos = 0;
1012 struct ewah_iterator it;
1013 eword_t word;
1014
1015 ewah_iterator_init(&it, source);
1016
1017 while (ewah_iterator_next(&word, &it)) {
1018 uint32_t offset, bit_pos;
1019
34b935c0 1020 for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
7cc8f971
VM
1021 if ((word >> offset) == 0)
1022 break;
1023
1024 offset += ewah_bit_ctz64(word >> offset);
1025
1026 bit_pos = reposition[pos + offset];
1027 if (bit_pos > 0)
1028 bitmap_set(dest, bit_pos - 1);
1029 else /* can't reuse, we don't have the object */
1030 return -1;
1031 }
1032
34b935c0 1033 pos += BITS_IN_EWORD;
7cc8f971
VM
1034 }
1035 return 0;
1036}
1037
3ae5fa07
JT
1038int rebuild_existing_bitmaps(struct bitmap_index *bitmap_git,
1039 struct packing_data *mapping,
7cc8f971
VM
1040 khash_sha1 *reused_bitmaps,
1041 int show_progress)
1042{
1043 uint32_t i, num_objects;
1044 uint32_t *reposition;
1045 struct bitmap *rebuild;
1046 struct stored_bitmap *stored;
1047 struct progress *progress = NULL;
1048
1049 khiter_t hash_pos;
1050 int hash_ret;
1051
3ae5fa07 1052 num_objects = bitmap_git->pack->num_objects;
7cc8f971
VM
1053 reposition = xcalloc(num_objects, sizeof(uint32_t));
1054
1055 for (i = 0; i < num_objects; ++i) {
1056 const unsigned char *sha1;
1057 struct revindex_entry *entry;
1058 struct object_entry *oe;
1059
3ae5fa07
JT
1060 entry = &bitmap_git->pack->revindex[i];
1061 sha1 = nth_packed_object_sha1(bitmap_git->pack, entry->nr);
7cc8f971
VM
1062 oe = packlist_find(mapping, sha1, NULL);
1063
1064 if (oe)
06af3bba 1065 reposition[i] = oe_in_pack_pos(mapping, oe) + 1;
7cc8f971
VM
1066 }
1067
1068 rebuild = bitmap_new();
1069 i = 0;
1070
1071 if (show_progress)
1072 progress = start_progress("Reusing bitmaps", 0);
1073
3ae5fa07 1074 kh_foreach_value(bitmap_git->bitmaps, stored, {
7cc8f971
VM
1075 if (stored->flags & BITMAP_FLAG_REUSE) {
1076 if (!rebuild_bitmap(reposition,
1077 lookup_stored_bitmap(stored),
1078 rebuild)) {
1079 hash_pos = kh_put_sha1(reused_bitmaps,
1080 stored->sha1,
1081 &hash_ret);
1082 kh_value(reused_bitmaps, hash_pos) =
1083 bitmap_to_ewah(rebuild);
1084 }
1085 bitmap_reset(rebuild);
1086 display_progress(progress, ++i);
1087 }
1088 });
1089
1090 stop_progress(&progress);
1091
1092 free(reposition);
1093 bitmap_free(rebuild);
1094 return 0;
1095}