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Commit | Line | Data |
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a3407730 | 1 | #include "cache.h" |
fc59e748 | 2 | #include "csum-file.h" |
396f2570 | 3 | #include "dir.h" |
fc59e748 | 4 | #include "lockfile.h" |
396f2570 | 5 | #include "packfile.h" |
4d80560c | 6 | #include "object-store.h" |
fe1ed56f | 7 | #include "packfile.h" |
a3407730 DS |
8 | #include "midx.h" |
9 | ||
fc59e748 DS |
10 | #define MIDX_SIGNATURE 0x4d494458 /* "MIDX" */ |
11 | #define MIDX_VERSION 1 | |
4d80560c DS |
12 | #define MIDX_BYTE_FILE_VERSION 4 |
13 | #define MIDX_BYTE_HASH_VERSION 5 | |
14 | #define MIDX_BYTE_NUM_CHUNKS 6 | |
15 | #define MIDX_BYTE_NUM_PACKS 8 | |
fc59e748 DS |
16 | #define MIDX_HASH_VERSION 1 |
17 | #define MIDX_HEADER_SIZE 12 | |
4d80560c DS |
18 | #define MIDX_HASH_LEN 20 |
19 | #define MIDX_MIN_SIZE (MIDX_HEADER_SIZE + MIDX_HASH_LEN) | |
fc59e748 | 20 | |
32f3c541 DS |
21 | #define MIDX_MAX_CHUNKS 1 |
22 | #define MIDX_CHUNK_ALIGNMENT 4 | |
23 | #define MIDX_CHUNKID_PACKNAMES 0x504e414d /* "PNAM" */ | |
24 | #define MIDX_CHUNKLOOKUP_WIDTH (sizeof(uint32_t) + sizeof(uint64_t)) | |
25 | ||
fc59e748 DS |
26 | static char *get_midx_filename(const char *object_dir) |
27 | { | |
28 | return xstrfmt("%s/pack/multi-pack-index", object_dir); | |
29 | } | |
30 | ||
4d80560c DS |
31 | struct multi_pack_index *load_multi_pack_index(const char *object_dir) |
32 | { | |
33 | struct multi_pack_index *m = NULL; | |
34 | int fd; | |
35 | struct stat st; | |
36 | size_t midx_size; | |
37 | void *midx_map = NULL; | |
38 | uint32_t hash_version; | |
39 | char *midx_name = get_midx_filename(object_dir); | |
32f3c541 | 40 | uint32_t i; |
3227565c | 41 | const char *cur_pack_name; |
4d80560c DS |
42 | |
43 | fd = git_open(midx_name); | |
44 | ||
45 | if (fd < 0) | |
46 | goto cleanup_fail; | |
47 | if (fstat(fd, &st)) { | |
48 | error_errno(_("failed to read %s"), midx_name); | |
49 | goto cleanup_fail; | |
50 | } | |
51 | ||
52 | midx_size = xsize_t(st.st_size); | |
53 | ||
54 | if (midx_size < MIDX_MIN_SIZE) { | |
55 | error(_("multi-pack-index file %s is too small"), midx_name); | |
56 | goto cleanup_fail; | |
57 | } | |
58 | ||
59 | FREE_AND_NULL(midx_name); | |
60 | ||
61 | midx_map = xmmap(NULL, midx_size, PROT_READ, MAP_PRIVATE, fd, 0); | |
62 | ||
63 | FLEX_ALLOC_MEM(m, object_dir, object_dir, strlen(object_dir)); | |
64 | m->fd = fd; | |
65 | m->data = midx_map; | |
66 | m->data_len = midx_size; | |
67 | ||
68 | m->signature = get_be32(m->data); | |
69 | if (m->signature != MIDX_SIGNATURE) { | |
70 | error(_("multi-pack-index signature 0x%08x does not match signature 0x%08x"), | |
71 | m->signature, MIDX_SIGNATURE); | |
72 | goto cleanup_fail; | |
73 | } | |
74 | ||
75 | m->version = m->data[MIDX_BYTE_FILE_VERSION]; | |
76 | if (m->version != MIDX_VERSION) { | |
77 | error(_("multi-pack-index version %d not recognized"), | |
78 | m->version); | |
79 | goto cleanup_fail; | |
80 | } | |
81 | ||
82 | hash_version = m->data[MIDX_BYTE_HASH_VERSION]; | |
83 | if (hash_version != MIDX_HASH_VERSION) { | |
84 | error(_("hash version %u does not match"), hash_version); | |
85 | goto cleanup_fail; | |
86 | } | |
87 | m->hash_len = MIDX_HASH_LEN; | |
88 | ||
89 | m->num_chunks = m->data[MIDX_BYTE_NUM_CHUNKS]; | |
90 | ||
91 | m->num_packs = get_be32(m->data + MIDX_BYTE_NUM_PACKS); | |
92 | ||
32f3c541 DS |
93 | for (i = 0; i < m->num_chunks; i++) { |
94 | uint32_t chunk_id = get_be32(m->data + MIDX_HEADER_SIZE + | |
95 | MIDX_CHUNKLOOKUP_WIDTH * i); | |
96 | uint64_t chunk_offset = get_be64(m->data + MIDX_HEADER_SIZE + 4 + | |
97 | MIDX_CHUNKLOOKUP_WIDTH * i); | |
98 | ||
99 | switch (chunk_id) { | |
100 | case MIDX_CHUNKID_PACKNAMES: | |
101 | m->chunk_pack_names = m->data + chunk_offset; | |
102 | break; | |
103 | ||
104 | case 0: | |
105 | die(_("terminating multi-pack-index chunk id appears earlier than expected")); | |
106 | break; | |
107 | ||
108 | default: | |
109 | /* | |
110 | * Do nothing on unrecognized chunks, allowing future | |
111 | * extensions to add optional chunks. | |
112 | */ | |
113 | break; | |
114 | } | |
115 | } | |
116 | ||
117 | if (!m->chunk_pack_names) | |
118 | die(_("multi-pack-index missing required pack-name chunk")); | |
119 | ||
3227565c DS |
120 | m->pack_names = xcalloc(m->num_packs, sizeof(*m->pack_names)); |
121 | ||
122 | cur_pack_name = (const char *)m->chunk_pack_names; | |
123 | for (i = 0; i < m->num_packs; i++) { | |
124 | m->pack_names[i] = cur_pack_name; | |
125 | ||
126 | cur_pack_name += strlen(cur_pack_name) + 1; | |
127 | ||
128 | if (i && strcmp(m->pack_names[i], m->pack_names[i - 1]) <= 0) { | |
129 | error(_("multi-pack-index pack names out of order: '%s' before '%s'"), | |
130 | m->pack_names[i - 1], | |
131 | m->pack_names[i]); | |
132 | goto cleanup_fail; | |
133 | } | |
134 | } | |
135 | ||
4d80560c DS |
136 | return m; |
137 | ||
138 | cleanup_fail: | |
139 | free(m); | |
140 | free(midx_name); | |
141 | if (midx_map) | |
142 | munmap(midx_map, midx_size); | |
143 | if (0 <= fd) | |
144 | close(fd); | |
145 | return NULL; | |
146 | } | |
147 | ||
fc59e748 DS |
148 | static size_t write_midx_header(struct hashfile *f, |
149 | unsigned char num_chunks, | |
150 | uint32_t num_packs) | |
151 | { | |
152 | unsigned char byte_values[4]; | |
153 | ||
154 | hashwrite_be32(f, MIDX_SIGNATURE); | |
155 | byte_values[0] = MIDX_VERSION; | |
156 | byte_values[1] = MIDX_HASH_VERSION; | |
157 | byte_values[2] = num_chunks; | |
158 | byte_values[3] = 0; /* unused */ | |
159 | hashwrite(f, byte_values, sizeof(byte_values)); | |
160 | hashwrite_be32(f, num_packs); | |
161 | ||
162 | return MIDX_HEADER_SIZE; | |
163 | } | |
164 | ||
396f2570 DS |
165 | struct pack_list { |
166 | struct packed_git **list; | |
32f3c541 | 167 | char **names; |
396f2570 DS |
168 | uint32_t nr; |
169 | uint32_t alloc_list; | |
32f3c541 DS |
170 | uint32_t alloc_names; |
171 | size_t pack_name_concat_len; | |
396f2570 DS |
172 | }; |
173 | ||
174 | static void add_pack_to_midx(const char *full_path, size_t full_path_len, | |
175 | const char *file_name, void *data) | |
176 | { | |
177 | struct pack_list *packs = (struct pack_list *)data; | |
178 | ||
179 | if (ends_with(file_name, ".idx")) { | |
180 | ALLOC_GROW(packs->list, packs->nr + 1, packs->alloc_list); | |
32f3c541 | 181 | ALLOC_GROW(packs->names, packs->nr + 1, packs->alloc_names); |
396f2570 DS |
182 | |
183 | packs->list[packs->nr] = add_packed_git(full_path, | |
184 | full_path_len, | |
185 | 0); | |
fe1ed56f | 186 | |
396f2570 DS |
187 | if (!packs->list[packs->nr]) { |
188 | warning(_("failed to add packfile '%s'"), | |
189 | full_path); | |
190 | return; | |
191 | } | |
192 | ||
fe1ed56f DS |
193 | if (open_pack_index(packs->list[packs->nr])) { |
194 | warning(_("failed to open pack-index '%s'"), | |
195 | full_path); | |
196 | close_pack(packs->list[packs->nr]); | |
197 | FREE_AND_NULL(packs->list[packs->nr]); | |
198 | return; | |
199 | } | |
200 | ||
32f3c541 DS |
201 | packs->names[packs->nr] = xstrdup(file_name); |
202 | packs->pack_name_concat_len += strlen(file_name) + 1; | |
396f2570 DS |
203 | packs->nr++; |
204 | } | |
205 | } | |
206 | ||
32f3c541 DS |
207 | struct pack_pair { |
208 | uint32_t pack_int_id; | |
209 | char *pack_name; | |
210 | }; | |
211 | ||
212 | static int pack_pair_compare(const void *_a, const void *_b) | |
213 | { | |
214 | struct pack_pair *a = (struct pack_pair *)_a; | |
215 | struct pack_pair *b = (struct pack_pair *)_b; | |
216 | return strcmp(a->pack_name, b->pack_name); | |
217 | } | |
218 | ||
219 | static void sort_packs_by_name(char **pack_names, uint32_t nr_packs, uint32_t *perm) | |
220 | { | |
221 | uint32_t i; | |
222 | struct pack_pair *pairs; | |
223 | ||
224 | ALLOC_ARRAY(pairs, nr_packs); | |
225 | ||
226 | for (i = 0; i < nr_packs; i++) { | |
227 | pairs[i].pack_int_id = i; | |
228 | pairs[i].pack_name = pack_names[i]; | |
229 | } | |
230 | ||
231 | QSORT(pairs, nr_packs, pack_pair_compare); | |
232 | ||
233 | for (i = 0; i < nr_packs; i++) { | |
234 | pack_names[i] = pairs[i].pack_name; | |
235 | perm[pairs[i].pack_int_id] = i; | |
236 | } | |
237 | ||
238 | free(pairs); | |
239 | } | |
240 | ||
fe1ed56f DS |
241 | struct pack_midx_entry { |
242 | struct object_id oid; | |
243 | uint32_t pack_int_id; | |
244 | time_t pack_mtime; | |
245 | uint64_t offset; | |
246 | }; | |
247 | ||
248 | static int midx_oid_compare(const void *_a, const void *_b) | |
249 | { | |
250 | const struct pack_midx_entry *a = (const struct pack_midx_entry *)_a; | |
251 | const struct pack_midx_entry *b = (const struct pack_midx_entry *)_b; | |
252 | int cmp = oidcmp(&a->oid, &b->oid); | |
253 | ||
254 | if (cmp) | |
255 | return cmp; | |
256 | ||
257 | if (a->pack_mtime > b->pack_mtime) | |
258 | return -1; | |
259 | else if (a->pack_mtime < b->pack_mtime) | |
260 | return 1; | |
261 | ||
262 | return a->pack_int_id - b->pack_int_id; | |
263 | } | |
264 | ||
265 | static void fill_pack_entry(uint32_t pack_int_id, | |
266 | struct packed_git *p, | |
267 | uint32_t cur_object, | |
268 | struct pack_midx_entry *entry) | |
269 | { | |
270 | if (!nth_packed_object_oid(&entry->oid, p, cur_object)) | |
271 | die(_("failed to locate object %d in packfile"), cur_object); | |
272 | ||
273 | entry->pack_int_id = pack_int_id; | |
274 | entry->pack_mtime = p->mtime; | |
275 | ||
276 | entry->offset = nth_packed_object_offset(p, cur_object); | |
277 | } | |
278 | ||
279 | /* | |
280 | * It is possible to artificially get into a state where there are many | |
281 | * duplicate copies of objects. That can create high memory pressure if | |
282 | * we are to create a list of all objects before de-duplication. To reduce | |
283 | * this memory pressure without a significant performance drop, automatically | |
284 | * group objects by the first byte of their object id. Use the IDX fanout | |
285 | * tables to group the data, copy to a local array, then sort. | |
286 | * | |
287 | * Copy only the de-duplicated entries (selected by most-recent modified time | |
288 | * of a packfile containing the object). | |
289 | */ | |
290 | static struct pack_midx_entry *get_sorted_entries(struct packed_git **p, | |
291 | uint32_t *perm, | |
292 | uint32_t nr_packs, | |
293 | uint32_t *nr_objects) | |
294 | { | |
295 | uint32_t cur_fanout, cur_pack, cur_object; | |
296 | uint32_t alloc_fanout, alloc_objects, total_objects = 0; | |
297 | struct pack_midx_entry *entries_by_fanout = NULL; | |
298 | struct pack_midx_entry *deduplicated_entries = NULL; | |
299 | ||
300 | for (cur_pack = 0; cur_pack < nr_packs; cur_pack++) | |
301 | total_objects += p[cur_pack]->num_objects; | |
302 | ||
303 | /* | |
304 | * As we de-duplicate by fanout value, we expect the fanout | |
305 | * slices to be evenly distributed, with some noise. Hence, | |
306 | * allocate slightly more than one 256th. | |
307 | */ | |
308 | alloc_objects = alloc_fanout = total_objects > 3200 ? total_objects / 200 : 16; | |
309 | ||
310 | ALLOC_ARRAY(entries_by_fanout, alloc_fanout); | |
311 | ALLOC_ARRAY(deduplicated_entries, alloc_objects); | |
312 | *nr_objects = 0; | |
313 | ||
314 | for (cur_fanout = 0; cur_fanout < 256; cur_fanout++) { | |
315 | uint32_t nr_fanout = 0; | |
316 | ||
317 | for (cur_pack = 0; cur_pack < nr_packs; cur_pack++) { | |
318 | uint32_t start = 0, end; | |
319 | ||
320 | if (cur_fanout) | |
321 | start = get_pack_fanout(p[cur_pack], cur_fanout - 1); | |
322 | end = get_pack_fanout(p[cur_pack], cur_fanout); | |
323 | ||
324 | for (cur_object = start; cur_object < end; cur_object++) { | |
325 | ALLOC_GROW(entries_by_fanout, nr_fanout + 1, alloc_fanout); | |
326 | fill_pack_entry(perm[cur_pack], p[cur_pack], cur_object, &entries_by_fanout[nr_fanout]); | |
327 | nr_fanout++; | |
328 | } | |
329 | } | |
330 | ||
331 | QSORT(entries_by_fanout, nr_fanout, midx_oid_compare); | |
332 | ||
333 | /* | |
334 | * The batch is now sorted by OID and then mtime (descending). | |
335 | * Take only the first duplicate. | |
336 | */ | |
337 | for (cur_object = 0; cur_object < nr_fanout; cur_object++) { | |
338 | if (cur_object && !oidcmp(&entries_by_fanout[cur_object - 1].oid, | |
339 | &entries_by_fanout[cur_object].oid)) | |
340 | continue; | |
341 | ||
342 | ALLOC_GROW(deduplicated_entries, *nr_objects + 1, alloc_objects); | |
343 | memcpy(&deduplicated_entries[*nr_objects], | |
344 | &entries_by_fanout[cur_object], | |
345 | sizeof(struct pack_midx_entry)); | |
346 | (*nr_objects)++; | |
347 | } | |
348 | } | |
349 | ||
350 | free(entries_by_fanout); | |
351 | return deduplicated_entries; | |
352 | } | |
353 | ||
32f3c541 DS |
354 | static size_t write_midx_pack_names(struct hashfile *f, |
355 | char **pack_names, | |
356 | uint32_t num_packs) | |
357 | { | |
358 | uint32_t i; | |
359 | unsigned char padding[MIDX_CHUNK_ALIGNMENT]; | |
360 | size_t written = 0; | |
361 | ||
362 | for (i = 0; i < num_packs; i++) { | |
363 | size_t writelen = strlen(pack_names[i]) + 1; | |
364 | ||
365 | if (i && strcmp(pack_names[i], pack_names[i - 1]) <= 0) | |
366 | BUG("incorrect pack-file order: %s before %s", | |
367 | pack_names[i - 1], | |
368 | pack_names[i]); | |
369 | ||
370 | hashwrite(f, pack_names[i], writelen); | |
371 | written += writelen; | |
372 | } | |
373 | ||
374 | /* add padding to be aligned */ | |
375 | i = MIDX_CHUNK_ALIGNMENT - (written % MIDX_CHUNK_ALIGNMENT); | |
376 | if (i < MIDX_CHUNK_ALIGNMENT) { | |
377 | memset(padding, 0, sizeof(padding)); | |
378 | hashwrite(f, padding, i); | |
379 | written += i; | |
380 | } | |
381 | ||
382 | return written; | |
383 | } | |
384 | ||
a3407730 DS |
385 | int write_midx_file(const char *object_dir) |
386 | { | |
32f3c541 | 387 | unsigned char cur_chunk, num_chunks = 0; |
fc59e748 | 388 | char *midx_name; |
396f2570 | 389 | uint32_t i; |
fc59e748 DS |
390 | struct hashfile *f = NULL; |
391 | struct lock_file lk; | |
396f2570 | 392 | struct pack_list packs; |
32f3c541 DS |
393 | uint32_t *pack_perm = NULL; |
394 | uint64_t written = 0; | |
395 | uint32_t chunk_ids[MIDX_MAX_CHUNKS + 1]; | |
396 | uint64_t chunk_offsets[MIDX_MAX_CHUNKS + 1]; | |
fe1ed56f DS |
397 | uint32_t nr_entries; |
398 | struct pack_midx_entry *entries = NULL; | |
fc59e748 DS |
399 | |
400 | midx_name = get_midx_filename(object_dir); | |
401 | if (safe_create_leading_directories(midx_name)) { | |
402 | UNLEAK(midx_name); | |
403 | die_errno(_("unable to create leading directories of %s"), | |
404 | midx_name); | |
405 | } | |
406 | ||
396f2570 DS |
407 | packs.nr = 0; |
408 | packs.alloc_list = 16; | |
32f3c541 | 409 | packs.alloc_names = 16; |
396f2570 | 410 | packs.list = NULL; |
32f3c541 | 411 | packs.pack_name_concat_len = 0; |
396f2570 | 412 | ALLOC_ARRAY(packs.list, packs.alloc_list); |
32f3c541 | 413 | ALLOC_ARRAY(packs.names, packs.alloc_names); |
396f2570 DS |
414 | |
415 | for_each_file_in_pack_dir(object_dir, add_pack_to_midx, &packs); | |
416 | ||
32f3c541 DS |
417 | if (packs.pack_name_concat_len % MIDX_CHUNK_ALIGNMENT) |
418 | packs.pack_name_concat_len += MIDX_CHUNK_ALIGNMENT - | |
419 | (packs.pack_name_concat_len % MIDX_CHUNK_ALIGNMENT); | |
420 | ||
421 | ALLOC_ARRAY(pack_perm, packs.nr); | |
422 | sort_packs_by_name(packs.names, packs.nr, pack_perm); | |
423 | ||
fe1ed56f DS |
424 | entries = get_sorted_entries(packs.list, pack_perm, packs.nr, &nr_entries); |
425 | ||
fc59e748 DS |
426 | hold_lock_file_for_update(&lk, midx_name, LOCK_DIE_ON_ERROR); |
427 | f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf); | |
428 | FREE_AND_NULL(midx_name); | |
429 | ||
32f3c541 DS |
430 | cur_chunk = 0; |
431 | num_chunks = 1; | |
432 | ||
433 | written = write_midx_header(f, num_chunks, packs.nr); | |
434 | ||
435 | chunk_ids[cur_chunk] = MIDX_CHUNKID_PACKNAMES; | |
436 | chunk_offsets[cur_chunk] = written + (num_chunks + 1) * MIDX_CHUNKLOOKUP_WIDTH; | |
437 | ||
438 | cur_chunk++; | |
439 | chunk_ids[cur_chunk] = 0; | |
440 | chunk_offsets[cur_chunk] = chunk_offsets[cur_chunk - 1] + packs.pack_name_concat_len; | |
441 | ||
442 | for (i = 0; i <= num_chunks; i++) { | |
443 | if (i && chunk_offsets[i] < chunk_offsets[i - 1]) | |
444 | BUG("incorrect chunk offsets: %"PRIu64" before %"PRIu64, | |
445 | chunk_offsets[i - 1], | |
446 | chunk_offsets[i]); | |
447 | ||
448 | if (chunk_offsets[i] % MIDX_CHUNK_ALIGNMENT) | |
449 | BUG("chunk offset %"PRIu64" is not properly aligned", | |
450 | chunk_offsets[i]); | |
451 | ||
452 | hashwrite_be32(f, chunk_ids[i]); | |
453 | hashwrite_be32(f, chunk_offsets[i] >> 32); | |
454 | hashwrite_be32(f, chunk_offsets[i]); | |
455 | ||
456 | written += MIDX_CHUNKLOOKUP_WIDTH; | |
457 | } | |
458 | ||
459 | for (i = 0; i < num_chunks; i++) { | |
460 | if (written != chunk_offsets[i]) | |
461 | BUG("incorrect chunk offset (%"PRIu64" != %"PRIu64") for chunk id %"PRIx32, | |
462 | chunk_offsets[i], | |
463 | written, | |
464 | chunk_ids[i]); | |
465 | ||
466 | switch (chunk_ids[i]) { | |
467 | case MIDX_CHUNKID_PACKNAMES: | |
468 | written += write_midx_pack_names(f, packs.names, packs.nr); | |
469 | break; | |
470 | ||
471 | default: | |
472 | BUG("trying to write unknown chunk id %"PRIx32, | |
473 | chunk_ids[i]); | |
474 | } | |
475 | } | |
476 | ||
477 | if (written != chunk_offsets[num_chunks]) | |
478 | BUG("incorrect final offset %"PRIu64" != %"PRIu64, | |
479 | written, | |
480 | chunk_offsets[num_chunks]); | |
fc59e748 DS |
481 | |
482 | finalize_hashfile(f, NULL, CSUM_FSYNC | CSUM_HASH_IN_STREAM); | |
483 | commit_lock_file(&lk); | |
484 | ||
396f2570 DS |
485 | for (i = 0; i < packs.nr; i++) { |
486 | if (packs.list[i]) { | |
487 | close_pack(packs.list[i]); | |
488 | free(packs.list[i]); | |
489 | } | |
32f3c541 | 490 | free(packs.names[i]); |
396f2570 DS |
491 | } |
492 | ||
493 | free(packs.list); | |
32f3c541 | 494 | free(packs.names); |
fe1ed56f | 495 | free(entries); |
a3407730 DS |
496 | return 0; |
497 | } |