The ninth batch
[git.git] / pack-bitmap-write.c
blob88d9e696a546a8db20d3ff7147a1bb15f8651d36
1 #include "cache.h"
2 #include "object-store.h"
3 #include "commit.h"
4 #include "tag.h"
5 #include "diff.h"
6 #include "revision.h"
7 #include "list-objects.h"
8 #include "progress.h"
9 #include "pack-revindex.h"
10 #include "pack.h"
11 #include "pack-bitmap.h"
12 #include "hash-lookup.h"
13 #include "pack-objects.h"
14 #include "commit-reach.h"
15 #include "prio-queue.h"
17 struct bitmapped_commit {
18 struct commit *commit;
19 struct ewah_bitmap *bitmap;
20 struct ewah_bitmap *write_as;
21 int flags;
22 int xor_offset;
23 uint32_t commit_pos;
26 struct bitmap_writer {
27 struct ewah_bitmap *commits;
28 struct ewah_bitmap *trees;
29 struct ewah_bitmap *blobs;
30 struct ewah_bitmap *tags;
32 kh_oid_map_t *bitmaps;
33 struct packing_data *to_pack;
35 struct bitmapped_commit *selected;
36 unsigned int selected_nr, selected_alloc;
38 struct progress *progress;
39 int show_progress;
40 unsigned char pack_checksum[GIT_MAX_RAWSZ];
43 static struct bitmap_writer writer;
45 void bitmap_writer_show_progress(int show)
47 writer.show_progress = show;
50 /**
51 * Build the initial type index for the packfile
53 void bitmap_writer_build_type_index(struct packing_data *to_pack,
54 struct pack_idx_entry **index,
55 uint32_t index_nr)
57 uint32_t i;
59 writer.commits = ewah_new();
60 writer.trees = ewah_new();
61 writer.blobs = ewah_new();
62 writer.tags = ewah_new();
63 ALLOC_ARRAY(to_pack->in_pack_pos, to_pack->nr_objects);
65 for (i = 0; i < index_nr; ++i) {
66 struct object_entry *entry = (struct object_entry *)index[i];
67 enum object_type real_type;
69 oe_set_in_pack_pos(to_pack, entry, i);
71 switch (oe_type(entry)) {
72 case OBJ_COMMIT:
73 case OBJ_TREE:
74 case OBJ_BLOB:
75 case OBJ_TAG:
76 real_type = oe_type(entry);
77 break;
79 default:
80 real_type = oid_object_info(to_pack->repo,
81 &entry->idx.oid, NULL);
82 break;
85 switch (real_type) {
86 case OBJ_COMMIT:
87 ewah_set(writer.commits, i);
88 break;
90 case OBJ_TREE:
91 ewah_set(writer.trees, i);
92 break;
94 case OBJ_BLOB:
95 ewah_set(writer.blobs, i);
96 break;
98 case OBJ_TAG:
99 ewah_set(writer.tags, i);
100 break;
102 default:
103 die("Missing type information for %s (%d/%d)",
104 oid_to_hex(&entry->idx.oid), real_type,
105 oe_type(entry));
111 * Compute the actual bitmaps
114 static inline void push_bitmapped_commit(struct commit *commit)
116 if (writer.selected_nr >= writer.selected_alloc) {
117 writer.selected_alloc = (writer.selected_alloc + 32) * 2;
118 REALLOC_ARRAY(writer.selected, writer.selected_alloc);
121 writer.selected[writer.selected_nr].commit = commit;
122 writer.selected[writer.selected_nr].bitmap = NULL;
123 writer.selected[writer.selected_nr].flags = 0;
125 writer.selected_nr++;
128 static uint32_t find_object_pos(const struct object_id *oid)
130 struct object_entry *entry = packlist_find(writer.to_pack, oid);
132 if (!entry) {
133 die("Failed to write bitmap index. Packfile doesn't have full closure "
134 "(object %s is missing)", oid_to_hex(oid));
137 return oe_in_pack_pos(writer.to_pack, entry);
140 static void compute_xor_offsets(void)
142 static const int MAX_XOR_OFFSET_SEARCH = 10;
144 int i, next = 0;
146 while (next < writer.selected_nr) {
147 struct bitmapped_commit *stored = &writer.selected[next];
149 int best_offset = 0;
150 struct ewah_bitmap *best_bitmap = stored->bitmap;
151 struct ewah_bitmap *test_xor;
153 for (i = 1; i <= MAX_XOR_OFFSET_SEARCH; ++i) {
154 int curr = next - i;
156 if (curr < 0)
157 break;
159 test_xor = ewah_pool_new();
160 ewah_xor(writer.selected[curr].bitmap, stored->bitmap, test_xor);
162 if (test_xor->buffer_size < best_bitmap->buffer_size) {
163 if (best_bitmap != stored->bitmap)
164 ewah_pool_free(best_bitmap);
166 best_bitmap = test_xor;
167 best_offset = i;
168 } else {
169 ewah_pool_free(test_xor);
173 stored->xor_offset = best_offset;
174 stored->write_as = best_bitmap;
176 next++;
180 struct bb_commit {
181 struct commit_list *reverse_edges;
182 struct bitmap *commit_mask;
183 struct bitmap *bitmap;
184 unsigned selected:1,
185 maximal:1;
186 unsigned idx; /* within selected array */
189 define_commit_slab(bb_data, struct bb_commit);
191 struct bitmap_builder {
192 struct bb_data data;
193 struct commit **commits;
194 size_t commits_nr, commits_alloc;
197 static void bitmap_builder_init(struct bitmap_builder *bb,
198 struct bitmap_writer *writer,
199 struct bitmap_index *old_bitmap)
201 struct rev_info revs;
202 struct commit *commit;
203 struct commit_list *reusable = NULL;
204 struct commit_list *r;
205 unsigned int i, num_maximal = 0;
207 memset(bb, 0, sizeof(*bb));
208 init_bb_data(&bb->data);
210 reset_revision_walk();
211 repo_init_revisions(writer->to_pack->repo, &revs, NULL);
212 revs.topo_order = 1;
213 revs.first_parent_only = 1;
215 for (i = 0; i < writer->selected_nr; i++) {
216 struct commit *c = writer->selected[i].commit;
217 struct bb_commit *ent = bb_data_at(&bb->data, c);
219 ent->selected = 1;
220 ent->maximal = 1;
221 ent->idx = i;
223 ent->commit_mask = bitmap_new();
224 bitmap_set(ent->commit_mask, i);
226 add_pending_object(&revs, &c->object, "");
229 if (prepare_revision_walk(&revs))
230 die("revision walk setup failed");
232 while ((commit = get_revision(&revs))) {
233 struct commit_list *p = commit->parents;
234 struct bb_commit *c_ent;
236 parse_commit_or_die(commit);
238 c_ent = bb_data_at(&bb->data, commit);
241 * If there is no commit_mask, there is no reason to iterate
242 * over this commit; it is not selected (if it were, it would
243 * not have a blank commit mask) and all its children have
244 * existing bitmaps (see the comment starting with "This commit
245 * has an existing bitmap" below), so it does not contribute
246 * anything to the final bitmap file or its descendants.
248 if (!c_ent->commit_mask)
249 continue;
251 if (old_bitmap && bitmap_for_commit(old_bitmap, commit)) {
253 * This commit has an existing bitmap, so we can
254 * get its bits immediately without an object
255 * walk. That is, it is reusable as-is and there is no
256 * need to continue walking beyond it.
258 * Mark it as such and add it to bb->commits separately
259 * to avoid allocating a position in the commit mask.
261 commit_list_insert(commit, &reusable);
262 goto next;
265 if (c_ent->maximal) {
266 num_maximal++;
267 ALLOC_GROW(bb->commits, bb->commits_nr + 1, bb->commits_alloc);
268 bb->commits[bb->commits_nr++] = commit;
271 if (p) {
272 struct bb_commit *p_ent = bb_data_at(&bb->data, p->item);
273 int c_not_p, p_not_c;
275 if (!p_ent->commit_mask) {
276 p_ent->commit_mask = bitmap_new();
277 c_not_p = 1;
278 p_not_c = 0;
279 } else {
280 c_not_p = bitmap_is_subset(c_ent->commit_mask, p_ent->commit_mask);
281 p_not_c = bitmap_is_subset(p_ent->commit_mask, c_ent->commit_mask);
284 if (!c_not_p)
285 continue;
287 bitmap_or(p_ent->commit_mask, c_ent->commit_mask);
289 if (p_not_c)
290 p_ent->maximal = 1;
291 else {
292 p_ent->maximal = 0;
293 free_commit_list(p_ent->reverse_edges);
294 p_ent->reverse_edges = NULL;
297 if (c_ent->maximal) {
298 commit_list_insert(commit, &p_ent->reverse_edges);
299 } else {
300 struct commit_list *cc = c_ent->reverse_edges;
302 for (; cc; cc = cc->next) {
303 if (!commit_list_contains(cc->item, p_ent->reverse_edges))
304 commit_list_insert(cc->item, &p_ent->reverse_edges);
309 next:
310 bitmap_free(c_ent->commit_mask);
311 c_ent->commit_mask = NULL;
314 for (r = reusable; r; r = r->next) {
315 ALLOC_GROW(bb->commits, bb->commits_nr + 1, bb->commits_alloc);
316 bb->commits[bb->commits_nr++] = r->item;
319 trace2_data_intmax("pack-bitmap-write", the_repository,
320 "num_selected_commits", writer->selected_nr);
321 trace2_data_intmax("pack-bitmap-write", the_repository,
322 "num_maximal_commits", num_maximal);
324 free_commit_list(reusable);
327 static void bitmap_builder_clear(struct bitmap_builder *bb)
329 clear_bb_data(&bb->data);
330 free(bb->commits);
331 bb->commits_nr = bb->commits_alloc = 0;
334 static void fill_bitmap_tree(struct bitmap *bitmap,
335 struct tree *tree)
337 uint32_t pos;
338 struct tree_desc desc;
339 struct name_entry entry;
342 * If our bit is already set, then there is nothing to do. Both this
343 * tree and all of its children will be set.
345 pos = find_object_pos(&tree->object.oid);
346 if (bitmap_get(bitmap, pos))
347 return;
348 bitmap_set(bitmap, pos);
350 if (parse_tree(tree) < 0)
351 die("unable to load tree object %s",
352 oid_to_hex(&tree->object.oid));
353 init_tree_desc(&desc, tree->buffer, tree->size);
355 while (tree_entry(&desc, &entry)) {
356 switch (object_type(entry.mode)) {
357 case OBJ_TREE:
358 fill_bitmap_tree(bitmap,
359 lookup_tree(the_repository, &entry.oid));
360 break;
361 case OBJ_BLOB:
362 bitmap_set(bitmap, find_object_pos(&entry.oid));
363 break;
364 default:
365 /* Gitlink, etc; not reachable */
366 break;
370 free_tree_buffer(tree);
373 static void fill_bitmap_commit(struct bb_commit *ent,
374 struct commit *commit,
375 struct prio_queue *queue,
376 struct prio_queue *tree_queue,
377 struct bitmap_index *old_bitmap,
378 const uint32_t *mapping)
380 if (!ent->bitmap)
381 ent->bitmap = bitmap_new();
383 prio_queue_put(queue, commit);
385 while (queue->nr) {
386 struct commit_list *p;
387 struct commit *c = prio_queue_get(queue);
389 if (old_bitmap && mapping) {
390 struct ewah_bitmap *old = bitmap_for_commit(old_bitmap, c);
392 * If this commit has an old bitmap, then translate that
393 * bitmap and add its bits to this one. No need to walk
394 * parents or the tree for this commit.
396 if (old && !rebuild_bitmap(mapping, old, ent->bitmap))
397 continue;
401 * Mark ourselves and queue our tree. The commit
402 * walk ensures we cover all parents.
404 bitmap_set(ent->bitmap, find_object_pos(&c->object.oid));
405 prio_queue_put(tree_queue, get_commit_tree(c));
407 for (p = c->parents; p; p = p->next) {
408 int pos = find_object_pos(&p->item->object.oid);
409 if (!bitmap_get(ent->bitmap, pos)) {
410 bitmap_set(ent->bitmap, pos);
411 prio_queue_put(queue, p->item);
416 while (tree_queue->nr)
417 fill_bitmap_tree(ent->bitmap, prio_queue_get(tree_queue));
420 static void store_selected(struct bb_commit *ent, struct commit *commit)
422 struct bitmapped_commit *stored = &writer.selected[ent->idx];
423 khiter_t hash_pos;
424 int hash_ret;
426 stored->bitmap = bitmap_to_ewah(ent->bitmap);
428 hash_pos = kh_put_oid_map(writer.bitmaps, commit->object.oid, &hash_ret);
429 if (hash_ret == 0)
430 die("Duplicate entry when writing index: %s",
431 oid_to_hex(&commit->object.oid));
432 kh_value(writer.bitmaps, hash_pos) = stored;
435 void bitmap_writer_build(struct packing_data *to_pack)
437 struct bitmap_builder bb;
438 size_t i;
439 int nr_stored = 0; /* for progress */
440 struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
441 struct prio_queue tree_queue = { NULL };
442 struct bitmap_index *old_bitmap;
443 uint32_t *mapping;
445 writer.bitmaps = kh_init_oid_map();
446 writer.to_pack = to_pack;
448 if (writer.show_progress)
449 writer.progress = start_progress("Building bitmaps", writer.selected_nr);
450 trace2_region_enter("pack-bitmap-write", "building_bitmaps_total",
451 the_repository);
453 old_bitmap = prepare_bitmap_git(to_pack->repo);
454 if (old_bitmap)
455 mapping = create_bitmap_mapping(old_bitmap, to_pack);
456 else
457 mapping = NULL;
459 bitmap_builder_init(&bb, &writer, old_bitmap);
460 for (i = bb.commits_nr; i > 0; i--) {
461 struct commit *commit = bb.commits[i-1];
462 struct bb_commit *ent = bb_data_at(&bb.data, commit);
463 struct commit *child;
464 int reused = 0;
466 fill_bitmap_commit(ent, commit, &queue, &tree_queue,
467 old_bitmap, mapping);
469 if (ent->selected) {
470 store_selected(ent, commit);
471 nr_stored++;
472 display_progress(writer.progress, nr_stored);
475 while ((child = pop_commit(&ent->reverse_edges))) {
476 struct bb_commit *child_ent =
477 bb_data_at(&bb.data, child);
479 if (child_ent->bitmap)
480 bitmap_or(child_ent->bitmap, ent->bitmap);
481 else if (reused)
482 child_ent->bitmap = bitmap_dup(ent->bitmap);
483 else {
484 child_ent->bitmap = ent->bitmap;
485 reused = 1;
488 if (!reused)
489 bitmap_free(ent->bitmap);
490 ent->bitmap = NULL;
492 clear_prio_queue(&queue);
493 clear_prio_queue(&tree_queue);
494 bitmap_builder_clear(&bb);
495 free(mapping);
497 trace2_region_leave("pack-bitmap-write", "building_bitmaps_total",
498 the_repository);
500 stop_progress(&writer.progress);
502 compute_xor_offsets();
506 * Select the commits that will be bitmapped
508 static inline unsigned int next_commit_index(unsigned int idx)
510 static const unsigned int MIN_COMMITS = 100;
511 static const unsigned int MAX_COMMITS = 5000;
513 static const unsigned int MUST_REGION = 100;
514 static const unsigned int MIN_REGION = 20000;
516 unsigned int offset, next;
518 if (idx <= MUST_REGION)
519 return 0;
521 if (idx <= MIN_REGION) {
522 offset = idx - MUST_REGION;
523 return (offset < MIN_COMMITS) ? offset : MIN_COMMITS;
526 offset = idx - MIN_REGION;
527 next = (offset < MAX_COMMITS) ? offset : MAX_COMMITS;
529 return (next > MIN_COMMITS) ? next : MIN_COMMITS;
532 static int date_compare(const void *_a, const void *_b)
534 struct commit *a = *(struct commit **)_a;
535 struct commit *b = *(struct commit **)_b;
536 return (long)b->date - (long)a->date;
539 void bitmap_writer_select_commits(struct commit **indexed_commits,
540 unsigned int indexed_commits_nr,
541 int max_bitmaps)
543 unsigned int i = 0, j, next;
545 QSORT(indexed_commits, indexed_commits_nr, date_compare);
547 if (writer.show_progress)
548 writer.progress = start_progress("Selecting bitmap commits", 0);
550 if (indexed_commits_nr < 100) {
551 for (i = 0; i < indexed_commits_nr; ++i)
552 push_bitmapped_commit(indexed_commits[i]);
553 return;
556 for (;;) {
557 struct commit *chosen = NULL;
559 next = next_commit_index(i);
561 if (i + next >= indexed_commits_nr)
562 break;
564 if (max_bitmaps > 0 && writer.selected_nr >= max_bitmaps) {
565 writer.selected_nr = max_bitmaps;
566 break;
569 if (next == 0) {
570 chosen = indexed_commits[i];
571 } else {
572 chosen = indexed_commits[i + next];
574 for (j = 0; j <= next; ++j) {
575 struct commit *cm = indexed_commits[i + j];
577 if ((cm->object.flags & NEEDS_BITMAP) != 0) {
578 chosen = cm;
579 break;
582 if (cm->parents && cm->parents->next)
583 chosen = cm;
587 push_bitmapped_commit(chosen);
589 i += next + 1;
590 display_progress(writer.progress, i);
593 stop_progress(&writer.progress);
597 static int hashwrite_ewah_helper(void *f, const void *buf, size_t len)
599 /* hashwrite will die on error */
600 hashwrite(f, buf, len);
601 return len;
605 * Write the bitmap index to disk
607 static inline void dump_bitmap(struct hashfile *f, struct ewah_bitmap *bitmap)
609 if (ewah_serialize_to(bitmap, hashwrite_ewah_helper, f) < 0)
610 die("Failed to write bitmap index");
613 static const struct object_id *oid_access(size_t pos, const void *table)
615 const struct pack_idx_entry * const *index = table;
616 return &index[pos]->oid;
619 static void write_selected_commits_v1(struct hashfile *f,
620 struct pack_idx_entry **index,
621 uint32_t index_nr)
623 int i;
625 for (i = 0; i < writer.selected_nr; ++i) {
626 struct bitmapped_commit *stored = &writer.selected[i];
628 int commit_pos =
629 oid_pos(&stored->commit->object.oid, index, index_nr, oid_access);
631 if (commit_pos < 0)
632 BUG("trying to write commit not in index");
634 hashwrite_be32(f, commit_pos);
635 hashwrite_u8(f, stored->xor_offset);
636 hashwrite_u8(f, stored->flags);
638 dump_bitmap(f, stored->write_as);
642 static void write_hash_cache(struct hashfile *f,
643 struct pack_idx_entry **index,
644 uint32_t index_nr)
646 uint32_t i;
648 for (i = 0; i < index_nr; ++i) {
649 struct object_entry *entry = (struct object_entry *)index[i];
650 hashwrite_be32(f, entry->hash);
654 void bitmap_writer_set_checksum(unsigned char *sha1)
656 hashcpy(writer.pack_checksum, sha1);
659 void bitmap_writer_finish(struct pack_idx_entry **index,
660 uint32_t index_nr,
661 const char *filename,
662 uint16_t options)
664 static uint16_t default_version = 1;
665 static uint16_t flags = BITMAP_OPT_FULL_DAG;
666 struct strbuf tmp_file = STRBUF_INIT;
667 struct hashfile *f;
669 struct bitmap_disk_header header;
671 int fd = odb_mkstemp(&tmp_file, "pack/tmp_bitmap_XXXXXX");
673 f = hashfd(fd, tmp_file.buf);
675 memcpy(header.magic, BITMAP_IDX_SIGNATURE, sizeof(BITMAP_IDX_SIGNATURE));
676 header.version = htons(default_version);
677 header.options = htons(flags | options);
678 header.entry_count = htonl(writer.selected_nr);
679 hashcpy(header.checksum, writer.pack_checksum);
681 hashwrite(f, &header, sizeof(header) - GIT_MAX_RAWSZ + the_hash_algo->rawsz);
682 dump_bitmap(f, writer.commits);
683 dump_bitmap(f, writer.trees);
684 dump_bitmap(f, writer.blobs);
685 dump_bitmap(f, writer.tags);
686 write_selected_commits_v1(f, index, index_nr);
688 if (options & BITMAP_OPT_HASH_CACHE)
689 write_hash_cache(f, index, index_nr);
691 finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
693 if (adjust_shared_perm(tmp_file.buf))
694 die_errno("unable to make temporary bitmap file readable");
696 if (rename(tmp_file.buf, filename))
697 die_errno("unable to rename temporary bitmap file to '%s'", filename);
699 strbuf_release(&tmp_file);