Sync with 2.4.3
[git.git] / pack-bitmap-write.c
blobc05d1386af7210e75a1012f3772745315ecc3592
1 #include "cache.h"
2 #include "commit.h"
3 #include "tag.h"
4 #include "diff.h"
5 #include "revision.h"
6 #include "list-objects.h"
7 #include "progress.h"
8 #include "pack-revindex.h"
9 #include "pack.h"
10 #include "pack-bitmap.h"
11 #include "sha1-lookup.h"
12 #include "pack-objects.h"
14 struct bitmapped_commit {
15 struct commit *commit;
16 struct ewah_bitmap *bitmap;
17 struct ewah_bitmap *write_as;
18 int flags;
19 int xor_offset;
20 uint32_t commit_pos;
23 struct bitmap_writer {
24 struct ewah_bitmap *commits;
25 struct ewah_bitmap *trees;
26 struct ewah_bitmap *blobs;
27 struct ewah_bitmap *tags;
29 khash_sha1 *bitmaps;
30 khash_sha1 *reused;
31 struct packing_data *to_pack;
33 struct bitmapped_commit *selected;
34 unsigned int selected_nr, selected_alloc;
36 struct progress *progress;
37 int show_progress;
38 unsigned char pack_checksum[20];
41 static struct bitmap_writer writer;
43 void bitmap_writer_show_progress(int show)
45 writer.show_progress = show;
48 /**
49 * Build the initial type index for the packfile
51 void bitmap_writer_build_type_index(struct pack_idx_entry **index,
52 uint32_t index_nr)
54 uint32_t i;
56 writer.commits = ewah_new();
57 writer.trees = ewah_new();
58 writer.blobs = ewah_new();
59 writer.tags = ewah_new();
61 for (i = 0; i < index_nr; ++i) {
62 struct object_entry *entry = (struct object_entry *)index[i];
63 enum object_type real_type;
65 entry->in_pack_pos = i;
67 switch (entry->type) {
68 case OBJ_COMMIT:
69 case OBJ_TREE:
70 case OBJ_BLOB:
71 case OBJ_TAG:
72 real_type = entry->type;
73 break;
75 default:
76 real_type = sha1_object_info(entry->idx.sha1, NULL);
77 break;
80 switch (real_type) {
81 case OBJ_COMMIT:
82 ewah_set(writer.commits, i);
83 break;
85 case OBJ_TREE:
86 ewah_set(writer.trees, i);
87 break;
89 case OBJ_BLOB:
90 ewah_set(writer.blobs, i);
91 break;
93 case OBJ_TAG:
94 ewah_set(writer.tags, i);
95 break;
97 default:
98 die("Missing type information for %s (%d/%d)",
99 sha1_to_hex(entry->idx.sha1), real_type, entry->type);
105 * Compute the actual bitmaps
107 static struct object **seen_objects;
108 static unsigned int seen_objects_nr, seen_objects_alloc;
110 static inline void push_bitmapped_commit(struct commit *commit, struct ewah_bitmap *reused)
112 if (writer.selected_nr >= writer.selected_alloc) {
113 writer.selected_alloc = (writer.selected_alloc + 32) * 2;
114 REALLOC_ARRAY(writer.selected, writer.selected_alloc);
117 writer.selected[writer.selected_nr].commit = commit;
118 writer.selected[writer.selected_nr].bitmap = reused;
119 writer.selected[writer.selected_nr].flags = 0;
121 writer.selected_nr++;
124 static inline void mark_as_seen(struct object *object)
126 ALLOC_GROW(seen_objects, seen_objects_nr + 1, seen_objects_alloc);
127 seen_objects[seen_objects_nr++] = object;
130 static inline void reset_all_seen(void)
132 unsigned int i;
133 for (i = 0; i < seen_objects_nr; ++i) {
134 seen_objects[i]->flags &= ~(SEEN | ADDED | SHOWN);
136 seen_objects_nr = 0;
139 static uint32_t find_object_pos(const unsigned char *sha1)
141 struct object_entry *entry = packlist_find(writer.to_pack, sha1, NULL);
143 if (!entry) {
144 die("Failed to write bitmap index. Packfile doesn't have full closure "
145 "(object %s is missing)", sha1_to_hex(sha1));
148 return entry->in_pack_pos;
151 static void show_object(struct object *object, const struct name_path *path,
152 const char *last, void *data)
154 struct bitmap *base = data;
155 bitmap_set(base, find_object_pos(object->sha1));
156 mark_as_seen(object);
159 static void show_commit(struct commit *commit, void *data)
161 mark_as_seen((struct object *)commit);
164 static int
165 add_to_include_set(struct bitmap *base, struct commit *commit)
167 khiter_t hash_pos;
168 uint32_t bitmap_pos = find_object_pos(commit->object.sha1);
170 if (bitmap_get(base, bitmap_pos))
171 return 0;
173 hash_pos = kh_get_sha1(writer.bitmaps, commit->object.sha1);
174 if (hash_pos < kh_end(writer.bitmaps)) {
175 struct bitmapped_commit *bc = kh_value(writer.bitmaps, hash_pos);
176 bitmap_or_ewah(base, bc->bitmap);
177 return 0;
180 bitmap_set(base, bitmap_pos);
181 return 1;
184 static int
185 should_include(struct commit *commit, void *_data)
187 struct bitmap *base = _data;
189 if (!add_to_include_set(base, commit)) {
190 struct commit_list *parent = commit->parents;
192 mark_as_seen((struct object *)commit);
194 while (parent) {
195 parent->item->object.flags |= SEEN;
196 mark_as_seen((struct object *)parent->item);
197 parent = parent->next;
200 return 0;
203 return 1;
206 static void compute_xor_offsets(void)
208 static const int MAX_XOR_OFFSET_SEARCH = 10;
210 int i, next = 0;
212 while (next < writer.selected_nr) {
213 struct bitmapped_commit *stored = &writer.selected[next];
215 int best_offset = 0;
216 struct ewah_bitmap *best_bitmap = stored->bitmap;
217 struct ewah_bitmap *test_xor;
219 for (i = 1; i <= MAX_XOR_OFFSET_SEARCH; ++i) {
220 int curr = next - i;
222 if (curr < 0)
223 break;
225 test_xor = ewah_pool_new();
226 ewah_xor(writer.selected[curr].bitmap, stored->bitmap, test_xor);
228 if (test_xor->buffer_size < best_bitmap->buffer_size) {
229 if (best_bitmap != stored->bitmap)
230 ewah_pool_free(best_bitmap);
232 best_bitmap = test_xor;
233 best_offset = i;
234 } else {
235 ewah_pool_free(test_xor);
239 stored->xor_offset = best_offset;
240 stored->write_as = best_bitmap;
242 next++;
246 void bitmap_writer_build(struct packing_data *to_pack)
248 static const double REUSE_BITMAP_THRESHOLD = 0.2;
250 int i, reuse_after, need_reset;
251 struct bitmap *base = bitmap_new();
252 struct rev_info revs;
254 writer.bitmaps = kh_init_sha1();
255 writer.to_pack = to_pack;
257 if (writer.show_progress)
258 writer.progress = start_progress("Building bitmaps", writer.selected_nr);
260 init_revisions(&revs, NULL);
261 revs.tag_objects = 1;
262 revs.tree_objects = 1;
263 revs.blob_objects = 1;
264 revs.no_walk = 0;
266 revs.include_check = should_include;
267 reset_revision_walk();
269 reuse_after = writer.selected_nr * REUSE_BITMAP_THRESHOLD;
270 need_reset = 0;
272 for (i = writer.selected_nr - 1; i >= 0; --i) {
273 struct bitmapped_commit *stored;
274 struct object *object;
276 khiter_t hash_pos;
277 int hash_ret;
279 stored = &writer.selected[i];
280 object = (struct object *)stored->commit;
282 if (stored->bitmap == NULL) {
283 if (i < writer.selected_nr - 1 &&
284 (need_reset ||
285 !in_merge_bases(writer.selected[i + 1].commit,
286 stored->commit))) {
287 bitmap_reset(base);
288 reset_all_seen();
291 add_pending_object(&revs, object, "");
292 revs.include_check_data = base;
294 if (prepare_revision_walk(&revs))
295 die("revision walk setup failed");
297 traverse_commit_list(&revs, show_commit, show_object, base);
299 revs.pending.nr = 0;
300 revs.pending.alloc = 0;
301 revs.pending.objects = NULL;
303 stored->bitmap = bitmap_to_ewah(base);
304 need_reset = 0;
305 } else
306 need_reset = 1;
308 if (i >= reuse_after)
309 stored->flags |= BITMAP_FLAG_REUSE;
311 hash_pos = kh_put_sha1(writer.bitmaps, object->sha1, &hash_ret);
312 if (hash_ret == 0)
313 die("Duplicate entry when writing index: %s",
314 sha1_to_hex(object->sha1));
316 kh_value(writer.bitmaps, hash_pos) = stored;
317 display_progress(writer.progress, writer.selected_nr - i);
320 bitmap_free(base);
321 stop_progress(&writer.progress);
323 compute_xor_offsets();
327 * Select the commits that will be bitmapped
329 static inline unsigned int next_commit_index(unsigned int idx)
331 static const unsigned int MIN_COMMITS = 100;
332 static const unsigned int MAX_COMMITS = 5000;
334 static const unsigned int MUST_REGION = 100;
335 static const unsigned int MIN_REGION = 20000;
337 unsigned int offset, next;
339 if (idx <= MUST_REGION)
340 return 0;
342 if (idx <= MIN_REGION) {
343 offset = idx - MUST_REGION;
344 return (offset < MIN_COMMITS) ? offset : MIN_COMMITS;
347 offset = idx - MIN_REGION;
348 next = (offset < MAX_COMMITS) ? offset : MAX_COMMITS;
350 return (next > MIN_COMMITS) ? next : MIN_COMMITS;
353 static int date_compare(const void *_a, const void *_b)
355 struct commit *a = *(struct commit **)_a;
356 struct commit *b = *(struct commit **)_b;
357 return (long)b->date - (long)a->date;
360 void bitmap_writer_reuse_bitmaps(struct packing_data *to_pack)
362 if (prepare_bitmap_git() < 0)
363 return;
365 writer.reused = kh_init_sha1();
366 rebuild_existing_bitmaps(to_pack, writer.reused, writer.show_progress);
369 static struct ewah_bitmap *find_reused_bitmap(const unsigned char *sha1)
371 khiter_t hash_pos;
373 if (!writer.reused)
374 return NULL;
376 hash_pos = kh_get_sha1(writer.reused, sha1);
377 if (hash_pos >= kh_end(writer.reused))
378 return NULL;
380 return kh_value(writer.reused, hash_pos);
383 void bitmap_writer_select_commits(struct commit **indexed_commits,
384 unsigned int indexed_commits_nr,
385 int max_bitmaps)
387 unsigned int i = 0, j, next;
389 qsort(indexed_commits, indexed_commits_nr, sizeof(indexed_commits[0]),
390 date_compare);
392 if (writer.show_progress)
393 writer.progress = start_progress("Selecting bitmap commits", 0);
395 if (indexed_commits_nr < 100) {
396 for (i = 0; i < indexed_commits_nr; ++i)
397 push_bitmapped_commit(indexed_commits[i], NULL);
398 return;
401 for (;;) {
402 struct ewah_bitmap *reused_bitmap = NULL;
403 struct commit *chosen = NULL;
405 next = next_commit_index(i);
407 if (i + next >= indexed_commits_nr)
408 break;
410 if (max_bitmaps > 0 && writer.selected_nr >= max_bitmaps) {
411 writer.selected_nr = max_bitmaps;
412 break;
415 if (next == 0) {
416 chosen = indexed_commits[i];
417 reused_bitmap = find_reused_bitmap(chosen->object.sha1);
418 } else {
419 chosen = indexed_commits[i + next];
421 for (j = 0; j <= next; ++j) {
422 struct commit *cm = indexed_commits[i + j];
424 reused_bitmap = find_reused_bitmap(cm->object.sha1);
425 if (reused_bitmap || (cm->object.flags & NEEDS_BITMAP) != 0) {
426 chosen = cm;
427 break;
430 if (cm->parents && cm->parents->next)
431 chosen = cm;
435 push_bitmapped_commit(chosen, reused_bitmap);
437 i += next + 1;
438 display_progress(writer.progress, i);
441 stop_progress(&writer.progress);
445 static int sha1write_ewah_helper(void *f, const void *buf, size_t len)
447 /* sha1write will die on error */
448 sha1write(f, buf, len);
449 return len;
453 * Write the bitmap index to disk
455 static inline void dump_bitmap(struct sha1file *f, struct ewah_bitmap *bitmap)
457 if (ewah_serialize_to(bitmap, sha1write_ewah_helper, f) < 0)
458 die("Failed to write bitmap index");
461 static const unsigned char *sha1_access(size_t pos, void *table)
463 struct pack_idx_entry **index = table;
464 return index[pos]->sha1;
467 static void write_selected_commits_v1(struct sha1file *f,
468 struct pack_idx_entry **index,
469 uint32_t index_nr)
471 int i;
473 for (i = 0; i < writer.selected_nr; ++i) {
474 struct bitmapped_commit *stored = &writer.selected[i];
476 int commit_pos =
477 sha1_pos(stored->commit->object.sha1, index, index_nr, sha1_access);
479 if (commit_pos < 0)
480 die("BUG: trying to write commit not in index");
482 sha1write_be32(f, commit_pos);
483 sha1write_u8(f, stored->xor_offset);
484 sha1write_u8(f, stored->flags);
486 dump_bitmap(f, stored->write_as);
490 static void write_hash_cache(struct sha1file *f,
491 struct pack_idx_entry **index,
492 uint32_t index_nr)
494 uint32_t i;
496 for (i = 0; i < index_nr; ++i) {
497 struct object_entry *entry = (struct object_entry *)index[i];
498 uint32_t hash_value = htonl(entry->hash);
499 sha1write(f, &hash_value, sizeof(hash_value));
503 void bitmap_writer_set_checksum(unsigned char *sha1)
505 hashcpy(writer.pack_checksum, sha1);
508 void bitmap_writer_finish(struct pack_idx_entry **index,
509 uint32_t index_nr,
510 const char *filename,
511 uint16_t options)
513 static char tmp_file[PATH_MAX];
514 static uint16_t default_version = 1;
515 static uint16_t flags = BITMAP_OPT_FULL_DAG;
516 struct sha1file *f;
518 struct bitmap_disk_header header;
520 int fd = odb_mkstemp(tmp_file, sizeof(tmp_file), "pack/tmp_bitmap_XXXXXX");
522 if (fd < 0)
523 die_errno("unable to create '%s'", tmp_file);
524 f = sha1fd(fd, tmp_file);
526 memcpy(header.magic, BITMAP_IDX_SIGNATURE, sizeof(BITMAP_IDX_SIGNATURE));
527 header.version = htons(default_version);
528 header.options = htons(flags | options);
529 header.entry_count = htonl(writer.selected_nr);
530 hashcpy(header.checksum, writer.pack_checksum);
532 sha1write(f, &header, sizeof(header));
533 dump_bitmap(f, writer.commits);
534 dump_bitmap(f, writer.trees);
535 dump_bitmap(f, writer.blobs);
536 dump_bitmap(f, writer.tags);
537 write_selected_commits_v1(f, index, index_nr);
539 if (options & BITMAP_OPT_HASH_CACHE)
540 write_hash_cache(f, index, index_nr);
542 sha1close(f, NULL, CSUM_FSYNC);
544 if (adjust_shared_perm(tmp_file))
545 die_errno("unable to make temporary bitmap file readable");
547 if (rename(tmp_file, filename))
548 die_errno("unable to rename temporary bitmap file to '%s'", filename);