stash: remove now superfluos help for "stash push"
[git.git] / pack-bitmap-write.c
bloba8df5ce2ab67bfdb5445e4c02e4ad65032abe9a0
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.oid.hash,
77 NULL);
78 break;
81 switch (real_type) {
82 case OBJ_COMMIT:
83 ewah_set(writer.commits, i);
84 break;
86 case OBJ_TREE:
87 ewah_set(writer.trees, i);
88 break;
90 case OBJ_BLOB:
91 ewah_set(writer.blobs, i);
92 break;
94 case OBJ_TAG:
95 ewah_set(writer.tags, i);
96 break;
98 default:
99 die("Missing type information for %s (%d/%d)",
100 oid_to_hex(&entry->idx.oid), real_type,
101 entry->type);
107 * Compute the actual bitmaps
109 static struct object **seen_objects;
110 static unsigned int seen_objects_nr, seen_objects_alloc;
112 static inline void push_bitmapped_commit(struct commit *commit, struct ewah_bitmap *reused)
114 if (writer.selected_nr >= writer.selected_alloc) {
115 writer.selected_alloc = (writer.selected_alloc + 32) * 2;
116 REALLOC_ARRAY(writer.selected, writer.selected_alloc);
119 writer.selected[writer.selected_nr].commit = commit;
120 writer.selected[writer.selected_nr].bitmap = reused;
121 writer.selected[writer.selected_nr].flags = 0;
123 writer.selected_nr++;
126 static inline void mark_as_seen(struct object *object)
128 ALLOC_GROW(seen_objects, seen_objects_nr + 1, seen_objects_alloc);
129 seen_objects[seen_objects_nr++] = object;
132 static inline void reset_all_seen(void)
134 unsigned int i;
135 for (i = 0; i < seen_objects_nr; ++i) {
136 seen_objects[i]->flags &= ~(SEEN | ADDED | SHOWN);
138 seen_objects_nr = 0;
141 static uint32_t find_object_pos(const unsigned char *sha1)
143 struct object_entry *entry = packlist_find(writer.to_pack, sha1, NULL);
145 if (!entry) {
146 die("Failed to write bitmap index. Packfile doesn't have full closure "
147 "(object %s is missing)", sha1_to_hex(sha1));
150 return entry->in_pack_pos;
153 static void show_object(struct object *object, const char *name, void *data)
155 struct bitmap *base = data;
156 bitmap_set(base, find_object_pos(object->oid.hash));
157 mark_as_seen(object);
160 static void show_commit(struct commit *commit, void *data)
162 mark_as_seen((struct object *)commit);
165 static int
166 add_to_include_set(struct bitmap *base, struct commit *commit)
168 khiter_t hash_pos;
169 uint32_t bitmap_pos = find_object_pos(commit->object.oid.hash);
171 if (bitmap_get(base, bitmap_pos))
172 return 0;
174 hash_pos = kh_get_sha1(writer.bitmaps, commit->object.oid.hash);
175 if (hash_pos < kh_end(writer.bitmaps)) {
176 struct bitmapped_commit *bc = kh_value(writer.bitmaps, hash_pos);
177 bitmap_or_ewah(base, bc->bitmap);
178 return 0;
181 bitmap_set(base, bitmap_pos);
182 return 1;
185 static int
186 should_include(struct commit *commit, void *_data)
188 struct bitmap *base = _data;
190 if (!add_to_include_set(base, commit)) {
191 struct commit_list *parent = commit->parents;
193 mark_as_seen((struct object *)commit);
195 while (parent) {
196 parent->item->object.flags |= SEEN;
197 mark_as_seen((struct object *)parent->item);
198 parent = parent->next;
201 return 0;
204 return 1;
207 static void compute_xor_offsets(void)
209 static const int MAX_XOR_OFFSET_SEARCH = 10;
211 int i, next = 0;
213 while (next < writer.selected_nr) {
214 struct bitmapped_commit *stored = &writer.selected[next];
216 int best_offset = 0;
217 struct ewah_bitmap *best_bitmap = stored->bitmap;
218 struct ewah_bitmap *test_xor;
220 for (i = 1; i <= MAX_XOR_OFFSET_SEARCH; ++i) {
221 int curr = next - i;
223 if (curr < 0)
224 break;
226 test_xor = ewah_pool_new();
227 ewah_xor(writer.selected[curr].bitmap, stored->bitmap, test_xor);
229 if (test_xor->buffer_size < best_bitmap->buffer_size) {
230 if (best_bitmap != stored->bitmap)
231 ewah_pool_free(best_bitmap);
233 best_bitmap = test_xor;
234 best_offset = i;
235 } else {
236 ewah_pool_free(test_xor);
240 stored->xor_offset = best_offset;
241 stored->write_as = best_bitmap;
243 next++;
247 void bitmap_writer_build(struct packing_data *to_pack)
249 static const double REUSE_BITMAP_THRESHOLD = 0.2;
251 int i, reuse_after, need_reset;
252 struct bitmap *base = bitmap_new();
253 struct rev_info revs;
255 writer.bitmaps = kh_init_sha1();
256 writer.to_pack = to_pack;
258 if (writer.show_progress)
259 writer.progress = start_progress("Building bitmaps", writer.selected_nr);
261 init_revisions(&revs, NULL);
262 revs.tag_objects = 1;
263 revs.tree_objects = 1;
264 revs.blob_objects = 1;
265 revs.no_walk = 0;
267 revs.include_check = should_include;
268 reset_revision_walk();
270 reuse_after = writer.selected_nr * REUSE_BITMAP_THRESHOLD;
271 need_reset = 0;
273 for (i = writer.selected_nr - 1; i >= 0; --i) {
274 struct bitmapped_commit *stored;
275 struct object *object;
277 khiter_t hash_pos;
278 int hash_ret;
280 stored = &writer.selected[i];
281 object = (struct object *)stored->commit;
283 if (stored->bitmap == NULL) {
284 if (i < writer.selected_nr - 1 &&
285 (need_reset ||
286 !in_merge_bases(writer.selected[i + 1].commit,
287 stored->commit))) {
288 bitmap_reset(base);
289 reset_all_seen();
292 add_pending_object(&revs, object, "");
293 revs.include_check_data = base;
295 if (prepare_revision_walk(&revs))
296 die("revision walk setup failed");
298 traverse_commit_list(&revs, show_commit, show_object, base);
300 object_array_clear(&revs.pending);
302 stored->bitmap = bitmap_to_ewah(base);
303 need_reset = 0;
304 } else
305 need_reset = 1;
307 if (i >= reuse_after)
308 stored->flags |= BITMAP_FLAG_REUSE;
310 hash_pos = kh_put_sha1(writer.bitmaps, object->oid.hash, &hash_ret);
311 if (hash_ret == 0)
312 die("Duplicate entry when writing index: %s",
313 oid_to_hex(&object->oid));
315 kh_value(writer.bitmaps, hash_pos) = stored;
316 display_progress(writer.progress, writer.selected_nr - i);
319 bitmap_free(base);
320 stop_progress(&writer.progress);
322 compute_xor_offsets();
326 * Select the commits that will be bitmapped
328 static inline unsigned int next_commit_index(unsigned int idx)
330 static const unsigned int MIN_COMMITS = 100;
331 static const unsigned int MAX_COMMITS = 5000;
333 static const unsigned int MUST_REGION = 100;
334 static const unsigned int MIN_REGION = 20000;
336 unsigned int offset, next;
338 if (idx <= MUST_REGION)
339 return 0;
341 if (idx <= MIN_REGION) {
342 offset = idx - MUST_REGION;
343 return (offset < MIN_COMMITS) ? offset : MIN_COMMITS;
346 offset = idx - MIN_REGION;
347 next = (offset < MAX_COMMITS) ? offset : MAX_COMMITS;
349 return (next > MIN_COMMITS) ? next : MIN_COMMITS;
352 static int date_compare(const void *_a, const void *_b)
354 struct commit *a = *(struct commit **)_a;
355 struct commit *b = *(struct commit **)_b;
356 return (long)b->date - (long)a->date;
359 void bitmap_writer_reuse_bitmaps(struct packing_data *to_pack)
361 if (prepare_bitmap_git() < 0)
362 return;
364 writer.reused = kh_init_sha1();
365 rebuild_existing_bitmaps(to_pack, writer.reused, writer.show_progress);
368 static struct ewah_bitmap *find_reused_bitmap(const unsigned char *sha1)
370 khiter_t hash_pos;
372 if (!writer.reused)
373 return NULL;
375 hash_pos = kh_get_sha1(writer.reused, sha1);
376 if (hash_pos >= kh_end(writer.reused))
377 return NULL;
379 return kh_value(writer.reused, hash_pos);
382 void bitmap_writer_select_commits(struct commit **indexed_commits,
383 unsigned int indexed_commits_nr,
384 int max_bitmaps)
386 unsigned int i = 0, j, next;
388 QSORT(indexed_commits, indexed_commits_nr, date_compare);
390 if (writer.show_progress)
391 writer.progress = start_progress("Selecting bitmap commits", 0);
393 if (indexed_commits_nr < 100) {
394 for (i = 0; i < indexed_commits_nr; ++i)
395 push_bitmapped_commit(indexed_commits[i], NULL);
396 return;
399 for (;;) {
400 struct ewah_bitmap *reused_bitmap = NULL;
401 struct commit *chosen = NULL;
403 next = next_commit_index(i);
405 if (i + next >= indexed_commits_nr)
406 break;
408 if (max_bitmaps > 0 && writer.selected_nr >= max_bitmaps) {
409 writer.selected_nr = max_bitmaps;
410 break;
413 if (next == 0) {
414 chosen = indexed_commits[i];
415 reused_bitmap = find_reused_bitmap(chosen->object.oid.hash);
416 } else {
417 chosen = indexed_commits[i + next];
419 for (j = 0; j <= next; ++j) {
420 struct commit *cm = indexed_commits[i + j];
422 reused_bitmap = find_reused_bitmap(cm->object.oid.hash);
423 if (reused_bitmap || (cm->object.flags & NEEDS_BITMAP) != 0) {
424 chosen = cm;
425 break;
428 if (cm->parents && cm->parents->next)
429 chosen = cm;
433 push_bitmapped_commit(chosen, reused_bitmap);
435 i += next + 1;
436 display_progress(writer.progress, i);
439 stop_progress(&writer.progress);
443 static int sha1write_ewah_helper(void *f, const void *buf, size_t len)
445 /* sha1write will die on error */
446 sha1write(f, buf, len);
447 return len;
451 * Write the bitmap index to disk
453 static inline void dump_bitmap(struct sha1file *f, struct ewah_bitmap *bitmap)
455 if (ewah_serialize_to(bitmap, sha1write_ewah_helper, f) < 0)
456 die("Failed to write bitmap index");
459 static const unsigned char *sha1_access(size_t pos, void *table)
461 struct pack_idx_entry **index = table;
462 return index[pos]->oid.hash;
465 static void write_selected_commits_v1(struct sha1file *f,
466 struct pack_idx_entry **index,
467 uint32_t index_nr)
469 int i;
471 for (i = 0; i < writer.selected_nr; ++i) {
472 struct bitmapped_commit *stored = &writer.selected[i];
474 int commit_pos =
475 sha1_pos(stored->commit->object.oid.hash, index, index_nr, sha1_access);
477 if (commit_pos < 0)
478 die("BUG: trying to write commit not in index");
480 sha1write_be32(f, commit_pos);
481 sha1write_u8(f, stored->xor_offset);
482 sha1write_u8(f, stored->flags);
484 dump_bitmap(f, stored->write_as);
488 static void write_hash_cache(struct sha1file *f,
489 struct pack_idx_entry **index,
490 uint32_t index_nr)
492 uint32_t i;
494 for (i = 0; i < index_nr; ++i) {
495 struct object_entry *entry = (struct object_entry *)index[i];
496 uint32_t hash_value = htonl(entry->hash);
497 sha1write(f, &hash_value, sizeof(hash_value));
501 void bitmap_writer_set_checksum(unsigned char *sha1)
503 hashcpy(writer.pack_checksum, sha1);
506 void bitmap_writer_finish(struct pack_idx_entry **index,
507 uint32_t index_nr,
508 const char *filename,
509 uint16_t options)
511 static uint16_t default_version = 1;
512 static uint16_t flags = BITMAP_OPT_FULL_DAG;
513 struct strbuf tmp_file = STRBUF_INIT;
514 struct sha1file *f;
516 struct bitmap_disk_header header;
518 int fd = odb_mkstemp(&tmp_file, "pack/tmp_bitmap_XXXXXX");
520 f = sha1fd(fd, tmp_file.buf);
522 memcpy(header.magic, BITMAP_IDX_SIGNATURE, sizeof(BITMAP_IDX_SIGNATURE));
523 header.version = htons(default_version);
524 header.options = htons(flags | options);
525 header.entry_count = htonl(writer.selected_nr);
526 hashcpy(header.checksum, writer.pack_checksum);
528 sha1write(f, &header, sizeof(header));
529 dump_bitmap(f, writer.commits);
530 dump_bitmap(f, writer.trees);
531 dump_bitmap(f, writer.blobs);
532 dump_bitmap(f, writer.tags);
533 write_selected_commits_v1(f, index, index_nr);
535 if (options & BITMAP_OPT_HASH_CACHE)
536 write_hash_cache(f, index, index_nr);
538 sha1close(f, NULL, CSUM_FSYNC);
540 if (adjust_shared_perm(tmp_file.buf))
541 die_errno("unable to make temporary bitmap file readable");
543 if (rename(tmp_file.buf, filename))
544 die_errno("unable to rename temporary bitmap file to '%s'", filename);
546 strbuf_release(&tmp_file);