The third batch
[git.git] / pack-bitmap-write.c
blob5566e94abed9f0838d4c1d999ee8e90159000256
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 "sha1-lookup.h"
13 #include "pack-objects.h"
14 #include "commit-reach.h"
16 struct bitmapped_commit {
17 struct commit *commit;
18 struct ewah_bitmap *bitmap;
19 struct ewah_bitmap *write_as;
20 int flags;
21 int xor_offset;
22 uint32_t commit_pos;
25 struct bitmap_writer {
26 struct ewah_bitmap *commits;
27 struct ewah_bitmap *trees;
28 struct ewah_bitmap *blobs;
29 struct ewah_bitmap *tags;
31 khash_sha1 *bitmaps;
32 khash_sha1 *reused;
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
113 static struct object **seen_objects;
114 static unsigned int seen_objects_nr, seen_objects_alloc;
116 static inline void push_bitmapped_commit(struct commit *commit, struct ewah_bitmap *reused)
118 if (writer.selected_nr >= writer.selected_alloc) {
119 writer.selected_alloc = (writer.selected_alloc + 32) * 2;
120 REALLOC_ARRAY(writer.selected, writer.selected_alloc);
123 writer.selected[writer.selected_nr].commit = commit;
124 writer.selected[writer.selected_nr].bitmap = reused;
125 writer.selected[writer.selected_nr].flags = 0;
127 writer.selected_nr++;
130 static inline void mark_as_seen(struct object *object)
132 ALLOC_GROW(seen_objects, seen_objects_nr + 1, seen_objects_alloc);
133 seen_objects[seen_objects_nr++] = object;
136 static inline void reset_all_seen(void)
138 unsigned int i;
139 for (i = 0; i < seen_objects_nr; ++i) {
140 seen_objects[i]->flags &= ~(SEEN | ADDED | SHOWN);
142 seen_objects_nr = 0;
145 static uint32_t find_object_pos(const unsigned char *sha1)
147 struct object_entry *entry = packlist_find(writer.to_pack, sha1, NULL);
149 if (!entry) {
150 die("Failed to write bitmap index. Packfile doesn't have full closure "
151 "(object %s is missing)", sha1_to_hex(sha1));
154 return oe_in_pack_pos(writer.to_pack, entry);
157 static void show_object(struct object *object, const char *name, void *data)
159 struct bitmap *base = data;
160 bitmap_set(base, find_object_pos(object->oid.hash));
161 mark_as_seen(object);
164 static void show_commit(struct commit *commit, void *data)
166 mark_as_seen((struct object *)commit);
169 static int
170 add_to_include_set(struct bitmap *base, struct commit *commit)
172 khiter_t hash_pos;
173 uint32_t bitmap_pos = find_object_pos(commit->object.oid.hash);
175 if (bitmap_get(base, bitmap_pos))
176 return 0;
178 hash_pos = kh_get_sha1(writer.bitmaps, commit->object.oid.hash);
179 if (hash_pos < kh_end(writer.bitmaps)) {
180 struct bitmapped_commit *bc = kh_value(writer.bitmaps, hash_pos);
181 bitmap_or_ewah(base, bc->bitmap);
182 return 0;
185 bitmap_set(base, bitmap_pos);
186 return 1;
189 static int
190 should_include(struct commit *commit, void *_data)
192 struct bitmap *base = _data;
194 if (!add_to_include_set(base, commit)) {
195 struct commit_list *parent = commit->parents;
197 mark_as_seen((struct object *)commit);
199 while (parent) {
200 parent->item->object.flags |= SEEN;
201 mark_as_seen((struct object *)parent->item);
202 parent = parent->next;
205 return 0;
208 return 1;
211 static void compute_xor_offsets(void)
213 static const int MAX_XOR_OFFSET_SEARCH = 10;
215 int i, next = 0;
217 while (next < writer.selected_nr) {
218 struct bitmapped_commit *stored = &writer.selected[next];
220 int best_offset = 0;
221 struct ewah_bitmap *best_bitmap = stored->bitmap;
222 struct ewah_bitmap *test_xor;
224 for (i = 1; i <= MAX_XOR_OFFSET_SEARCH; ++i) {
225 int curr = next - i;
227 if (curr < 0)
228 break;
230 test_xor = ewah_pool_new();
231 ewah_xor(writer.selected[curr].bitmap, stored->bitmap, test_xor);
233 if (test_xor->buffer_size < best_bitmap->buffer_size) {
234 if (best_bitmap != stored->bitmap)
235 ewah_pool_free(best_bitmap);
237 best_bitmap = test_xor;
238 best_offset = i;
239 } else {
240 ewah_pool_free(test_xor);
244 stored->xor_offset = best_offset;
245 stored->write_as = best_bitmap;
247 next++;
251 void bitmap_writer_build(struct packing_data *to_pack)
253 static const double REUSE_BITMAP_THRESHOLD = 0.2;
255 int i, reuse_after, need_reset;
256 struct bitmap *base = bitmap_new();
257 struct rev_info revs;
259 writer.bitmaps = kh_init_sha1();
260 writer.to_pack = to_pack;
262 if (writer.show_progress)
263 writer.progress = start_progress("Building bitmaps", writer.selected_nr);
265 repo_init_revisions(to_pack->repo, &revs, NULL);
266 revs.tag_objects = 1;
267 revs.tree_objects = 1;
268 revs.blob_objects = 1;
269 revs.no_walk = 0;
271 revs.include_check = should_include;
272 reset_revision_walk();
274 reuse_after = writer.selected_nr * REUSE_BITMAP_THRESHOLD;
275 need_reset = 0;
277 for (i = writer.selected_nr - 1; i >= 0; --i) {
278 struct bitmapped_commit *stored;
279 struct object *object;
281 khiter_t hash_pos;
282 int hash_ret;
284 stored = &writer.selected[i];
285 object = (struct object *)stored->commit;
287 if (stored->bitmap == NULL) {
288 if (i < writer.selected_nr - 1 &&
289 (need_reset ||
290 !in_merge_bases(writer.selected[i + 1].commit,
291 stored->commit))) {
292 bitmap_reset(base);
293 reset_all_seen();
296 add_pending_object(&revs, object, "");
297 revs.include_check_data = base;
299 if (prepare_revision_walk(&revs))
300 die("revision walk setup failed");
302 traverse_commit_list(&revs, show_commit, show_object, base);
304 object_array_clear(&revs.pending);
306 stored->bitmap = bitmap_to_ewah(base);
307 need_reset = 0;
308 } else
309 need_reset = 1;
311 if (i >= reuse_after)
312 stored->flags |= BITMAP_FLAG_REUSE;
314 hash_pos = kh_put_sha1(writer.bitmaps, object->oid.hash, &hash_ret);
315 if (hash_ret == 0)
316 die("Duplicate entry when writing index: %s",
317 oid_to_hex(&object->oid));
319 kh_value(writer.bitmaps, hash_pos) = stored;
320 display_progress(writer.progress, writer.selected_nr - i);
323 bitmap_free(base);
324 stop_progress(&writer.progress);
326 compute_xor_offsets();
330 * Select the commits that will be bitmapped
332 static inline unsigned int next_commit_index(unsigned int idx)
334 static const unsigned int MIN_COMMITS = 100;
335 static const unsigned int MAX_COMMITS = 5000;
337 static const unsigned int MUST_REGION = 100;
338 static const unsigned int MIN_REGION = 20000;
340 unsigned int offset, next;
342 if (idx <= MUST_REGION)
343 return 0;
345 if (idx <= MIN_REGION) {
346 offset = idx - MUST_REGION;
347 return (offset < MIN_COMMITS) ? offset : MIN_COMMITS;
350 offset = idx - MIN_REGION;
351 next = (offset < MAX_COMMITS) ? offset : MAX_COMMITS;
353 return (next > MIN_COMMITS) ? next : MIN_COMMITS;
356 static int date_compare(const void *_a, const void *_b)
358 struct commit *a = *(struct commit **)_a;
359 struct commit *b = *(struct commit **)_b;
360 return (long)b->date - (long)a->date;
363 void bitmap_writer_reuse_bitmaps(struct packing_data *to_pack)
365 struct bitmap_index *bitmap_git;
366 if (!(bitmap_git = prepare_bitmap_git(to_pack->repo)))
367 return;
369 writer.reused = kh_init_sha1();
370 rebuild_existing_bitmaps(bitmap_git, to_pack, writer.reused,
371 writer.show_progress);
373 * NEEDSWORK: rebuild_existing_bitmaps() makes writer.reused reference
374 * some bitmaps in bitmap_git, so we can't free the latter.
378 static struct ewah_bitmap *find_reused_bitmap(const unsigned char *sha1)
380 khiter_t hash_pos;
382 if (!writer.reused)
383 return NULL;
385 hash_pos = kh_get_sha1(writer.reused, sha1);
386 if (hash_pos >= kh_end(writer.reused))
387 return NULL;
389 return kh_value(writer.reused, hash_pos);
392 void bitmap_writer_select_commits(struct commit **indexed_commits,
393 unsigned int indexed_commits_nr,
394 int max_bitmaps)
396 unsigned int i = 0, j, next;
398 QSORT(indexed_commits, indexed_commits_nr, date_compare);
400 if (writer.show_progress)
401 writer.progress = start_progress("Selecting bitmap commits", 0);
403 if (indexed_commits_nr < 100) {
404 for (i = 0; i < indexed_commits_nr; ++i)
405 push_bitmapped_commit(indexed_commits[i], NULL);
406 return;
409 for (;;) {
410 struct ewah_bitmap *reused_bitmap = NULL;
411 struct commit *chosen = NULL;
413 next = next_commit_index(i);
415 if (i + next >= indexed_commits_nr)
416 break;
418 if (max_bitmaps > 0 && writer.selected_nr >= max_bitmaps) {
419 writer.selected_nr = max_bitmaps;
420 break;
423 if (next == 0) {
424 chosen = indexed_commits[i];
425 reused_bitmap = find_reused_bitmap(chosen->object.oid.hash);
426 } else {
427 chosen = indexed_commits[i + next];
429 for (j = 0; j <= next; ++j) {
430 struct commit *cm = indexed_commits[i + j];
432 reused_bitmap = find_reused_bitmap(cm->object.oid.hash);
433 if (reused_bitmap || (cm->object.flags & NEEDS_BITMAP) != 0) {
434 chosen = cm;
435 break;
438 if (cm->parents && cm->parents->next)
439 chosen = cm;
443 push_bitmapped_commit(chosen, reused_bitmap);
445 i += next + 1;
446 display_progress(writer.progress, i);
449 stop_progress(&writer.progress);
453 static int hashwrite_ewah_helper(void *f, const void *buf, size_t len)
455 /* hashwrite will die on error */
456 hashwrite(f, buf, len);
457 return len;
461 * Write the bitmap index to disk
463 static inline void dump_bitmap(struct hashfile *f, struct ewah_bitmap *bitmap)
465 if (ewah_serialize_to(bitmap, hashwrite_ewah_helper, f) < 0)
466 die("Failed to write bitmap index");
469 static const unsigned char *sha1_access(size_t pos, void *table)
471 struct pack_idx_entry **index = table;
472 return index[pos]->oid.hash;
475 static void write_selected_commits_v1(struct hashfile *f,
476 struct pack_idx_entry **index,
477 uint32_t index_nr)
479 int i;
481 for (i = 0; i < writer.selected_nr; ++i) {
482 struct bitmapped_commit *stored = &writer.selected[i];
484 int commit_pos =
485 sha1_pos(stored->commit->object.oid.hash, index, index_nr, sha1_access);
487 if (commit_pos < 0)
488 BUG("trying to write commit not in index");
490 hashwrite_be32(f, commit_pos);
491 hashwrite_u8(f, stored->xor_offset);
492 hashwrite_u8(f, stored->flags);
494 dump_bitmap(f, stored->write_as);
498 static void write_hash_cache(struct hashfile *f,
499 struct pack_idx_entry **index,
500 uint32_t index_nr)
502 uint32_t i;
504 for (i = 0; i < index_nr; ++i) {
505 struct object_entry *entry = (struct object_entry *)index[i];
506 uint32_t hash_value = htonl(entry->hash);
507 hashwrite(f, &hash_value, sizeof(hash_value));
511 void bitmap_writer_set_checksum(unsigned char *sha1)
513 hashcpy(writer.pack_checksum, sha1);
516 void bitmap_writer_finish(struct pack_idx_entry **index,
517 uint32_t index_nr,
518 const char *filename,
519 uint16_t options)
521 static uint16_t default_version = 1;
522 static uint16_t flags = BITMAP_OPT_FULL_DAG;
523 struct strbuf tmp_file = STRBUF_INIT;
524 struct hashfile *f;
526 struct bitmap_disk_header header;
528 int fd = odb_mkstemp(&tmp_file, "pack/tmp_bitmap_XXXXXX");
530 f = hashfd(fd, tmp_file.buf);
532 memcpy(header.magic, BITMAP_IDX_SIGNATURE, sizeof(BITMAP_IDX_SIGNATURE));
533 header.version = htons(default_version);
534 header.options = htons(flags | options);
535 header.entry_count = htonl(writer.selected_nr);
536 hashcpy(header.checksum, writer.pack_checksum);
538 hashwrite(f, &header, sizeof(header));
539 dump_bitmap(f, writer.commits);
540 dump_bitmap(f, writer.trees);
541 dump_bitmap(f, writer.blobs);
542 dump_bitmap(f, writer.tags);
543 write_selected_commits_v1(f, index, index_nr);
545 if (options & BITMAP_OPT_HASH_CACHE)
546 write_hash_cache(f, index, index_nr);
548 finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
550 if (adjust_shared_perm(tmp_file.buf))
551 die_errno("unable to make temporary bitmap file readable");
553 if (rename(tmp_file.buf, filename))
554 die_errno("unable to rename temporary bitmap file to '%s'", filename);
556 strbuf_release(&tmp_file);