csum-file: refactor finalize_hashfile() method
[git/git.git] / pack-bitmap-write.c
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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 "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"
13
14struct 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;
21};
22
23struct bitmap_writer {
24 struct ewah_bitmap *commits;
25 struct ewah_bitmap *trees;
26 struct ewah_bitmap *blobs;
27 struct ewah_bitmap *tags;
28
29 khash_sha1 *bitmaps;
30 khash_sha1 *reused;
31 struct packing_data *to_pack;
32
33 struct bitmapped_commit *selected;
34 unsigned int selected_nr, selected_alloc;
35
36 struct progress *progress;
37 int show_progress;
38 unsigned char pack_checksum[20];
39};
40
41static struct bitmap_writer writer;
42
43void bitmap_writer_show_progress(int show)
44{
45 writer.show_progress = show;
46}
47
48/**
49 * Build the initial type index for the packfile
50 */
51void bitmap_writer_build_type_index(struct pack_idx_entry **index,
52 uint32_t index_nr)
53{
54 uint32_t i;
55
56 writer.commits = ewah_new();
57 writer.trees = ewah_new();
58 writer.blobs = ewah_new();
59 writer.tags = ewah_new();
60
61 for (i = 0; i < index_nr; ++i) {
62 struct object_entry *entry = (struct object_entry *)index[i];
63 enum object_type real_type;
64
65 entry->in_pack_pos = i;
66
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;
74
75 default:
e6a492b7 76 real_type = sha1_object_info(entry->idx.oid.hash,
77 NULL);
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78 break;
79 }
80
81 switch (real_type) {
82 case OBJ_COMMIT:
83 ewah_set(writer.commits, i);
84 break;
85
86 case OBJ_TREE:
87 ewah_set(writer.trees, i);
88 break;
89
90 case OBJ_BLOB:
91 ewah_set(writer.blobs, i);
92 break;
93
94 case OBJ_TAG:
95 ewah_set(writer.tags, i);
96 break;
97
98 default:
99 die("Missing type information for %s (%d/%d)",
e6a492b7 100 oid_to_hex(&entry->idx.oid), real_type,
101 entry->type);
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102 }
103 }
104}
105
106/**
107 * Compute the actual bitmaps
108 */
109static struct object **seen_objects;
110static unsigned int seen_objects_nr, seen_objects_alloc;
111
112static inline void push_bitmapped_commit(struct commit *commit, struct ewah_bitmap *reused)
113{
114 if (writer.selected_nr >= writer.selected_alloc) {
115 writer.selected_alloc = (writer.selected_alloc + 32) * 2;
2756ca43 116 REALLOC_ARRAY(writer.selected, writer.selected_alloc);
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117 }
118
119 writer.selected[writer.selected_nr].commit = commit;
120 writer.selected[writer.selected_nr].bitmap = reused;
121 writer.selected[writer.selected_nr].flags = 0;
122
123 writer.selected_nr++;
124}
125
126static inline void mark_as_seen(struct object *object)
127{
128 ALLOC_GROW(seen_objects, seen_objects_nr + 1, seen_objects_alloc);
129 seen_objects[seen_objects_nr++] = object;
130}
131
132static inline void reset_all_seen(void)
133{
134 unsigned int i;
135 for (i = 0; i < seen_objects_nr; ++i) {
136 seen_objects[i]->flags &= ~(SEEN | ADDED | SHOWN);
137 }
138 seen_objects_nr = 0;
139}
140
141static uint32_t find_object_pos(const unsigned char *sha1)
142{
143 struct object_entry *entry = packlist_find(writer.to_pack, sha1, NULL);
144
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));
148 }
149
150 return entry->in_pack_pos;
151}
152
de1e67d0 153static void show_object(struct object *object, const char *name, void *data)
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154{
155 struct bitmap *base = data;
ed1c9977 156 bitmap_set(base, find_object_pos(object->oid.hash));
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157 mark_as_seen(object);
158}
159
160static void show_commit(struct commit *commit, void *data)
161{
162 mark_as_seen((struct object *)commit);
163}
164
165static int
166add_to_include_set(struct bitmap *base, struct commit *commit)
167{
168 khiter_t hash_pos;
ed1c9977 169 uint32_t bitmap_pos = find_object_pos(commit->object.oid.hash);
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170
171 if (bitmap_get(base, bitmap_pos))
172 return 0;
173
ed1c9977 174 hash_pos = kh_get_sha1(writer.bitmaps, commit->object.oid.hash);
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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;
179 }
180
181 bitmap_set(base, bitmap_pos);
182 return 1;
183}
184
185static int
186should_include(struct commit *commit, void *_data)
187{
188 struct bitmap *base = _data;
189
190 if (!add_to_include_set(base, commit)) {
191 struct commit_list *parent = commit->parents;
192
193 mark_as_seen((struct object *)commit);
194
195 while (parent) {
196 parent->item->object.flags |= SEEN;
197 mark_as_seen((struct object *)parent->item);
198 parent = parent->next;
199 }
200
201 return 0;
202 }
203
204 return 1;
205}
206
207static void compute_xor_offsets(void)
208{
209 static const int MAX_XOR_OFFSET_SEARCH = 10;
210
211 int i, next = 0;
212
213 while (next < writer.selected_nr) {
214 struct bitmapped_commit *stored = &writer.selected[next];
215
216 int best_offset = 0;
217 struct ewah_bitmap *best_bitmap = stored->bitmap;
218 struct ewah_bitmap *test_xor;
219
220 for (i = 1; i <= MAX_XOR_OFFSET_SEARCH; ++i) {
221 int curr = next - i;
222
223 if (curr < 0)
224 break;
225
226 test_xor = ewah_pool_new();
227 ewah_xor(writer.selected[curr].bitmap, stored->bitmap, test_xor);
228
229 if (test_xor->buffer_size < best_bitmap->buffer_size) {
230 if (best_bitmap != stored->bitmap)
231 ewah_pool_free(best_bitmap);
232
233 best_bitmap = test_xor;
234 best_offset = i;
235 } else {
236 ewah_pool_free(test_xor);
237 }
238 }
239
240 stored->xor_offset = best_offset;
241 stored->write_as = best_bitmap;
242
243 next++;
244 }
245}
246
247void bitmap_writer_build(struct packing_data *to_pack)
248{
249 static const double REUSE_BITMAP_THRESHOLD = 0.2;
250
251 int i, reuse_after, need_reset;
252 struct bitmap *base = bitmap_new();
253 struct rev_info revs;
254
255 writer.bitmaps = kh_init_sha1();
256 writer.to_pack = to_pack;
257
258 if (writer.show_progress)
259 writer.progress = start_progress("Building bitmaps", writer.selected_nr);
260
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;
266
267 revs.include_check = should_include;
268 reset_revision_walk();
269
270 reuse_after = writer.selected_nr * REUSE_BITMAP_THRESHOLD;
271 need_reset = 0;
272
273 for (i = writer.selected_nr - 1; i >= 0; --i) {
274 struct bitmapped_commit *stored;
275 struct object *object;
276
277 khiter_t hash_pos;
278 int hash_ret;
279
280 stored = &writer.selected[i];
281 object = (struct object *)stored->commit;
282
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();
290 }
291
292 add_pending_object(&revs, object, "");
293 revs.include_check_data = base;
294
295 if (prepare_revision_walk(&revs))
296 die("revision walk setup failed");
297
298 traverse_commit_list(&revs, show_commit, show_object, base);
299
4d01a7fa 300 object_array_clear(&revs.pending);
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301
302 stored->bitmap = bitmap_to_ewah(base);
303 need_reset = 0;
304 } else
305 need_reset = 1;
306
307 if (i >= reuse_after)
308 stored->flags |= BITMAP_FLAG_REUSE;
309
ed1c9977 310 hash_pos = kh_put_sha1(writer.bitmaps, object->oid.hash, &hash_ret);
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311 if (hash_ret == 0)
312 die("Duplicate entry when writing index: %s",
f2fd0760 313 oid_to_hex(&object->oid));
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314
315 kh_value(writer.bitmaps, hash_pos) = stored;
316 display_progress(writer.progress, writer.selected_nr - i);
317 }
318
319 bitmap_free(base);
320 stop_progress(&writer.progress);
321
322 compute_xor_offsets();
323}
324
325/**
326 * Select the commits that will be bitmapped
327 */
328static inline unsigned int next_commit_index(unsigned int idx)
329{
330 static const unsigned int MIN_COMMITS = 100;
331 static const unsigned int MAX_COMMITS = 5000;
332
333 static const unsigned int MUST_REGION = 100;
334 static const unsigned int MIN_REGION = 20000;
335
336 unsigned int offset, next;
337
338 if (idx <= MUST_REGION)
339 return 0;
340
341 if (idx <= MIN_REGION) {
342 offset = idx - MUST_REGION;
343 return (offset < MIN_COMMITS) ? offset : MIN_COMMITS;
344 }
345
346 offset = idx - MIN_REGION;
347 next = (offset < MAX_COMMITS) ? offset : MAX_COMMITS;
348
349 return (next > MIN_COMMITS) ? next : MIN_COMMITS;
350}
351
352static int date_compare(const void *_a, const void *_b)
353{
354 struct commit *a = *(struct commit **)_a;
355 struct commit *b = *(struct commit **)_b;
356 return (long)b->date - (long)a->date;
357}
358
359void bitmap_writer_reuse_bitmaps(struct packing_data *to_pack)
360{
361 if (prepare_bitmap_git() < 0)
362 return;
363
364 writer.reused = kh_init_sha1();
365 rebuild_existing_bitmaps(to_pack, writer.reused, writer.show_progress);
366}
367
368static struct ewah_bitmap *find_reused_bitmap(const unsigned char *sha1)
369{
370 khiter_t hash_pos;
371
372 if (!writer.reused)
373 return NULL;
374
375 hash_pos = kh_get_sha1(writer.reused, sha1);
376 if (hash_pos >= kh_end(writer.reused))
377 return NULL;
378
379 return kh_value(writer.reused, hash_pos);
380}
381
382void bitmap_writer_select_commits(struct commit **indexed_commits,
383 unsigned int indexed_commits_nr,
384 int max_bitmaps)
385{
386 unsigned int i = 0, j, next;
387
9ed0d8d6 388 QSORT(indexed_commits, indexed_commits_nr, date_compare);
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389
390 if (writer.show_progress)
391 writer.progress = start_progress("Selecting bitmap commits", 0);
392
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;
397 }
398
399 for (;;) {
400 struct ewah_bitmap *reused_bitmap = NULL;
401 struct commit *chosen = NULL;
402
403 next = next_commit_index(i);
404
405 if (i + next >= indexed_commits_nr)
406 break;
407
408 if (max_bitmaps > 0 && writer.selected_nr >= max_bitmaps) {
409 writer.selected_nr = max_bitmaps;
410 break;
411 }
412
413 if (next == 0) {
414 chosen = indexed_commits[i];
ed1c9977 415 reused_bitmap = find_reused_bitmap(chosen->object.oid.hash);
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416 } else {
417 chosen = indexed_commits[i + next];
418
419 for (j = 0; j <= next; ++j) {
420 struct commit *cm = indexed_commits[i + j];
421
ed1c9977 422 reused_bitmap = find_reused_bitmap(cm->object.oid.hash);
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423 if (reused_bitmap || (cm->object.flags & NEEDS_BITMAP) != 0) {
424 chosen = cm;
425 break;
426 }
427
428 if (cm->parents && cm->parents->next)
429 chosen = cm;
430 }
431 }
432
433 push_bitmapped_commit(chosen, reused_bitmap);
434
435 i += next + 1;
436 display_progress(writer.progress, i);
437 }
438
439 stop_progress(&writer.progress);
440}
441
442
98a3beab 443static int hashwrite_ewah_helper(void *f, const void *buf, size_t len)
7cc8f971 444{
98a3beab 445 /* hashwrite will die on error */
446 hashwrite(f, buf, len);
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447 return len;
448}
449
450/**
451 * Write the bitmap index to disk
452 */
98a3beab 453static inline void dump_bitmap(struct hashfile *f, struct ewah_bitmap *bitmap)
7cc8f971 454{
98a3beab 455 if (ewah_serialize_to(bitmap, hashwrite_ewah_helper, f) < 0)
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456 die("Failed to write bitmap index");
457}
458
459static const unsigned char *sha1_access(size_t pos, void *table)
460{
461 struct pack_idx_entry **index = table;
e6a492b7 462 return index[pos]->oid.hash;
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463}
464
98a3beab 465static void write_selected_commits_v1(struct hashfile *f,
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466 struct pack_idx_entry **index,
467 uint32_t index_nr)
468{
469 int i;
470
471 for (i = 0; i < writer.selected_nr; ++i) {
472 struct bitmapped_commit *stored = &writer.selected[i];
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473
474 int commit_pos =
ed1c9977 475 sha1_pos(stored->commit->object.oid.hash, index, index_nr, sha1_access);
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476
477 if (commit_pos < 0)
478 die("BUG: trying to write commit not in index");
479
98a3beab 480 hashwrite_be32(f, commit_pos);
481 hashwrite_u8(f, stored->xor_offset);
482 hashwrite_u8(f, stored->flags);
7cc8f971 483
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484 dump_bitmap(f, stored->write_as);
485 }
486}
487
98a3beab 488static void write_hash_cache(struct hashfile *f,
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489 struct pack_idx_entry **index,
490 uint32_t index_nr)
491{
492 uint32_t i;
493
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);
98a3beab 497 hashwrite(f, &hash_value, sizeof(hash_value));
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498 }
499}
500
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501void bitmap_writer_set_checksum(unsigned char *sha1)
502{
503 hashcpy(writer.pack_checksum, sha1);
504}
505
506void bitmap_writer_finish(struct pack_idx_entry **index,
507 uint32_t index_nr,
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508 const char *filename,
509 uint16_t options)
7cc8f971 510{
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511 static uint16_t default_version = 1;
512 static uint16_t flags = BITMAP_OPT_FULL_DAG;
594fa999 513 struct strbuf tmp_file = STRBUF_INIT;
98a3beab 514 struct hashfile *f;
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515
516 struct bitmap_disk_header header;
517
594fa999 518 int fd = odb_mkstemp(&tmp_file, "pack/tmp_bitmap_XXXXXX");
7cc8f971 519
98a3beab 520 f = hashfd(fd, tmp_file.buf);
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521
522 memcpy(header.magic, BITMAP_IDX_SIGNATURE, sizeof(BITMAP_IDX_SIGNATURE));
523 header.version = htons(default_version);
ae4f07fb 524 header.options = htons(flags | options);
7cc8f971 525 header.entry_count = htonl(writer.selected_nr);
50546b15 526 hashcpy(header.checksum, writer.pack_checksum);
7cc8f971 527
98a3beab 528 hashwrite(f, &header, sizeof(header));
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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);
534
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535 if (options & BITMAP_OPT_HASH_CACHE)
536 write_hash_cache(f, index, index_nr);
537
cfe83216 538 finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC | CSUM_CLOSE);
7cc8f971 539
594fa999 540 if (adjust_shared_perm(tmp_file.buf))
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541 die_errno("unable to make temporary bitmap file readable");
542
594fa999 543 if (rename(tmp_file.buf, filename))
7cc8f971 544 die_errno("unable to rename temporary bitmap file to '%s'", filename);
594fa999
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545
546 strbuf_release(&tmp_file);
7cc8f971 547}