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1 | /* | |
2 | * name-hash.c | |
3 | * | |
4 | * Hashing names in the index state | |
5 | * | |
6 | * Copyright (C) 2008 Linus Torvalds | |
7 | */ | |
8 | #include "cache.h" | |
9 | #include "thread-utils.h" | |
10 | ||
11 | struct dir_entry { | |
12 | struct hashmap_entry ent; | |
13 | struct dir_entry *parent; | |
14 | int nr; | |
15 | unsigned int namelen; | |
16 | char name[FLEX_ARRAY]; | |
17 | }; | |
18 | ||
19 | static int dir_entry_cmp(const void *unused_cmp_data, | |
20 | const struct hashmap_entry *eptr, | |
21 | const struct hashmap_entry *entry_or_key, | |
22 | const void *keydata) | |
23 | { | |
24 | const struct dir_entry *e1, *e2; | |
25 | const char *name = keydata; | |
26 | ||
27 | e1 = container_of(eptr, const struct dir_entry, ent); | |
28 | e2 = container_of(entry_or_key, const struct dir_entry, ent); | |
29 | ||
30 | return e1->namelen != e2->namelen || strncasecmp(e1->name, | |
31 | name ? name : e2->name, e1->namelen); | |
32 | } | |
33 | ||
34 | static struct dir_entry *find_dir_entry__hash(struct index_state *istate, | |
35 | const char *name, unsigned int namelen, unsigned int hash) | |
36 | { | |
37 | struct dir_entry key; | |
38 | hashmap_entry_init(&key.ent, hash); | |
39 | key.namelen = namelen; | |
40 | return hashmap_get_entry(&istate->dir_hash, &key, ent, name); | |
41 | } | |
42 | ||
43 | static struct dir_entry *find_dir_entry(struct index_state *istate, | |
44 | const char *name, unsigned int namelen) | |
45 | { | |
46 | return find_dir_entry__hash(istate, name, namelen, memihash(name, namelen)); | |
47 | } | |
48 | ||
49 | static struct dir_entry *hash_dir_entry(struct index_state *istate, | |
50 | struct cache_entry *ce, int namelen) | |
51 | { | |
52 | /* | |
53 | * Throw each directory component in the hash for quick lookup | |
54 | * during a git status. Directory components are stored without their | |
55 | * closing slash. Despite submodules being a directory, they never | |
56 | * reach this point, because they are stored | |
57 | * in index_state.name_hash (as ordinary cache_entries). | |
58 | */ | |
59 | struct dir_entry *dir; | |
60 | ||
61 | /* get length of parent directory */ | |
62 | while (namelen > 0 && !is_dir_sep(ce->name[namelen - 1])) | |
63 | namelen--; | |
64 | if (namelen <= 0) | |
65 | return NULL; | |
66 | namelen--; | |
67 | ||
68 | /* lookup existing entry for that directory */ | |
69 | dir = find_dir_entry(istate, ce->name, namelen); | |
70 | if (!dir) { | |
71 | /* not found, create it and add to hash table */ | |
72 | FLEX_ALLOC_MEM(dir, name, ce->name, namelen); | |
73 | hashmap_entry_init(&dir->ent, memihash(ce->name, namelen)); | |
74 | dir->namelen = namelen; | |
75 | hashmap_add(&istate->dir_hash, &dir->ent); | |
76 | ||
77 | /* recursively add missing parent directories */ | |
78 | dir->parent = hash_dir_entry(istate, ce, namelen); | |
79 | } | |
80 | return dir; | |
81 | } | |
82 | ||
83 | static void add_dir_entry(struct index_state *istate, struct cache_entry *ce) | |
84 | { | |
85 | /* Add reference to the directory entry (and parents if 0). */ | |
86 | struct dir_entry *dir = hash_dir_entry(istate, ce, ce_namelen(ce)); | |
87 | while (dir && !(dir->nr++)) | |
88 | dir = dir->parent; | |
89 | } | |
90 | ||
91 | static void remove_dir_entry(struct index_state *istate, struct cache_entry *ce) | |
92 | { | |
93 | /* | |
94 | * Release reference to the directory entry. If 0, remove and continue | |
95 | * with parent directory. | |
96 | */ | |
97 | struct dir_entry *dir = hash_dir_entry(istate, ce, ce_namelen(ce)); | |
98 | while (dir && !(--dir->nr)) { | |
99 | struct dir_entry *parent = dir->parent; | |
100 | hashmap_remove(&istate->dir_hash, &dir->ent, NULL); | |
101 | free(dir); | |
102 | dir = parent; | |
103 | } | |
104 | } | |
105 | ||
106 | static void hash_index_entry(struct index_state *istate, struct cache_entry *ce) | |
107 | { | |
108 | if (ce->ce_flags & CE_HASHED) | |
109 | return; | |
110 | ce->ce_flags |= CE_HASHED; | |
111 | hashmap_entry_init(&ce->ent, memihash(ce->name, ce_namelen(ce))); | |
112 | hashmap_add(&istate->name_hash, &ce->ent); | |
113 | ||
114 | if (ignore_case) | |
115 | add_dir_entry(istate, ce); | |
116 | } | |
117 | ||
118 | static int cache_entry_cmp(const void *unused_cmp_data, | |
119 | const struct hashmap_entry *eptr, | |
120 | const struct hashmap_entry *entry_or_key, | |
121 | const void *remove) | |
122 | { | |
123 | const struct cache_entry *ce1, *ce2; | |
124 | ||
125 | ce1 = container_of(eptr, const struct cache_entry, ent); | |
126 | ce2 = container_of(entry_or_key, const struct cache_entry, ent); | |
127 | ||
128 | /* | |
129 | * For remove_name_hash, find the exact entry (pointer equality); for | |
130 | * index_file_exists, find all entries with matching hash code and | |
131 | * decide whether the entry matches in same_name. | |
132 | */ | |
133 | return remove ? !(ce1 == ce2) : 0; | |
134 | } | |
135 | ||
136 | static int lazy_try_threaded = 1; | |
137 | static int lazy_nr_dir_threads; | |
138 | ||
139 | /* | |
140 | * Set a minimum number of cache_entries that we will handle per | |
141 | * thread and use that to decide how many threads to run (upto | |
142 | * the number on the system). | |
143 | * | |
144 | * For guidance setting the lower per-thread bound, see: | |
145 | * t/helper/test-lazy-init-name-hash --analyze | |
146 | */ | |
147 | #define LAZY_THREAD_COST (2000) | |
148 | ||
149 | /* | |
150 | * We use n mutexes to guard n partitions of the "istate->dir_hash" | |
151 | * hashtable. Since "find" and "insert" operations will hash to a | |
152 | * particular bucket and modify/search a single chain, we can say | |
153 | * that "all chains mod n" are guarded by the same mutex -- rather | |
154 | * than having a single mutex to guard the entire table. (This does | |
155 | * require that we disable "rehashing" on the hashtable.) | |
156 | * | |
157 | * So, a larger value here decreases the probability of a collision | |
158 | * and the time that each thread must wait for the mutex. | |
159 | */ | |
160 | #define LAZY_MAX_MUTEX (32) | |
161 | ||
162 | static pthread_mutex_t *lazy_dir_mutex_array; | |
163 | ||
164 | /* | |
165 | * An array of lazy_entry items is used by the n threads in | |
166 | * the directory parse (first) phase to (lock-free) store the | |
167 | * intermediate results. These values are then referenced by | |
168 | * the 2 threads in the second phase. | |
169 | */ | |
170 | struct lazy_entry { | |
171 | struct dir_entry *dir; | |
172 | unsigned int hash_dir; | |
173 | unsigned int hash_name; | |
174 | }; | |
175 | ||
176 | /* | |
177 | * Decide if we want to use threads (if available) to load | |
178 | * the hash tables. We set "lazy_nr_dir_threads" to zero when | |
179 | * it is not worth it. | |
180 | */ | |
181 | static int lookup_lazy_params(struct index_state *istate) | |
182 | { | |
183 | int nr_cpus; | |
184 | ||
185 | lazy_nr_dir_threads = 0; | |
186 | ||
187 | if (!lazy_try_threaded) | |
188 | return 0; | |
189 | ||
190 | /* | |
191 | * If we are respecting case, just use the original | |
192 | * code to build the "istate->name_hash". We don't | |
193 | * need the complexity here. | |
194 | */ | |
195 | if (!ignore_case) | |
196 | return 0; | |
197 | ||
198 | nr_cpus = online_cpus(); | |
199 | if (nr_cpus < 2) | |
200 | return 0; | |
201 | ||
202 | if (istate->cache_nr < 2 * LAZY_THREAD_COST) | |
203 | return 0; | |
204 | ||
205 | if (istate->cache_nr < nr_cpus * LAZY_THREAD_COST) | |
206 | nr_cpus = istate->cache_nr / LAZY_THREAD_COST; | |
207 | lazy_nr_dir_threads = nr_cpus; | |
208 | return lazy_nr_dir_threads; | |
209 | } | |
210 | ||
211 | /* | |
212 | * Initialize n mutexes for use when searching and inserting | |
213 | * into "istate->dir_hash". All "dir" threads are trying | |
214 | * to insert partial pathnames into the hash as they iterate | |
215 | * over their portions of the index, so lock contention is | |
216 | * high. | |
217 | * | |
218 | * However, the hashmap is going to put items into bucket | |
219 | * chains based on their hash values. Use that to create n | |
220 | * mutexes and lock on mutex[bucket(hash) % n]. This will | |
221 | * decrease the collision rate by (hopefully) by a factor of n. | |
222 | */ | |
223 | static void init_dir_mutex(void) | |
224 | { | |
225 | int j; | |
226 | ||
227 | lazy_dir_mutex_array = xcalloc(LAZY_MAX_MUTEX, sizeof(pthread_mutex_t)); | |
228 | ||
229 | for (j = 0; j < LAZY_MAX_MUTEX; j++) | |
230 | init_recursive_mutex(&lazy_dir_mutex_array[j]); | |
231 | } | |
232 | ||
233 | static void cleanup_dir_mutex(void) | |
234 | { | |
235 | int j; | |
236 | ||
237 | for (j = 0; j < LAZY_MAX_MUTEX; j++) | |
238 | pthread_mutex_destroy(&lazy_dir_mutex_array[j]); | |
239 | ||
240 | free(lazy_dir_mutex_array); | |
241 | } | |
242 | ||
243 | static void lock_dir_mutex(int j) | |
244 | { | |
245 | pthread_mutex_lock(&lazy_dir_mutex_array[j]); | |
246 | } | |
247 | ||
248 | static void unlock_dir_mutex(int j) | |
249 | { | |
250 | pthread_mutex_unlock(&lazy_dir_mutex_array[j]); | |
251 | } | |
252 | ||
253 | static inline int compute_dir_lock_nr( | |
254 | const struct hashmap *map, | |
255 | unsigned int hash) | |
256 | { | |
257 | return hashmap_bucket(map, hash) % LAZY_MAX_MUTEX; | |
258 | } | |
259 | ||
260 | static struct dir_entry *hash_dir_entry_with_parent_and_prefix( | |
261 | struct index_state *istate, | |
262 | struct dir_entry *parent, | |
263 | struct strbuf *prefix) | |
264 | { | |
265 | struct dir_entry *dir; | |
266 | unsigned int hash; | |
267 | int lock_nr; | |
268 | ||
269 | /* | |
270 | * Either we have a parent directory and path with slash(es) | |
271 | * or the directory is an immediate child of the root directory. | |
272 | */ | |
273 | assert((parent != NULL) ^ (strchr(prefix->buf, '/') == NULL)); | |
274 | ||
275 | if (parent) | |
276 | hash = memihash_cont(parent->ent.hash, | |
277 | prefix->buf + parent->namelen, | |
278 | prefix->len - parent->namelen); | |
279 | else | |
280 | hash = memihash(prefix->buf, prefix->len); | |
281 | ||
282 | lock_nr = compute_dir_lock_nr(&istate->dir_hash, hash); | |
283 | lock_dir_mutex(lock_nr); | |
284 | ||
285 | dir = find_dir_entry__hash(istate, prefix->buf, prefix->len, hash); | |
286 | if (!dir) { | |
287 | FLEX_ALLOC_MEM(dir, name, prefix->buf, prefix->len); | |
288 | hashmap_entry_init(&dir->ent, hash); | |
289 | dir->namelen = prefix->len; | |
290 | dir->parent = parent; | |
291 | hashmap_add(&istate->dir_hash, &dir->ent); | |
292 | ||
293 | if (parent) { | |
294 | unlock_dir_mutex(lock_nr); | |
295 | ||
296 | /* All I really need here is an InterlockedIncrement(&(parent->nr)) */ | |
297 | lock_nr = compute_dir_lock_nr(&istate->dir_hash, parent->ent.hash); | |
298 | lock_dir_mutex(lock_nr); | |
299 | parent->nr++; | |
300 | } | |
301 | } | |
302 | ||
303 | unlock_dir_mutex(lock_nr); | |
304 | ||
305 | return dir; | |
306 | } | |
307 | ||
308 | /* | |
309 | * handle_range_1() and handle_range_dir() are derived from | |
310 | * clear_ce_flags_1() and clear_ce_flags_dir() in unpack-trees.c | |
311 | * and handle the iteration over the entire array of index entries. | |
312 | * They use recursion for adjacent entries in the same parent | |
313 | * directory. | |
314 | */ | |
315 | static int handle_range_1( | |
316 | struct index_state *istate, | |
317 | int k_start, | |
318 | int k_end, | |
319 | struct dir_entry *parent, | |
320 | struct strbuf *prefix, | |
321 | struct lazy_entry *lazy_entries); | |
322 | ||
323 | static int handle_range_dir( | |
324 | struct index_state *istate, | |
325 | int k_start, | |
326 | int k_end, | |
327 | struct dir_entry *parent, | |
328 | struct strbuf *prefix, | |
329 | struct lazy_entry *lazy_entries, | |
330 | struct dir_entry **dir_new_out) | |
331 | { | |
332 | int rc, k; | |
333 | int input_prefix_len = prefix->len; | |
334 | struct dir_entry *dir_new; | |
335 | ||
336 | dir_new = hash_dir_entry_with_parent_and_prefix(istate, parent, prefix); | |
337 | ||
338 | strbuf_addch(prefix, '/'); | |
339 | ||
340 | /* | |
341 | * Scan forward in the index array for index entries having the same | |
342 | * path prefix (that are also in this directory). | |
343 | */ | |
344 | if (k_start + 1 >= k_end) | |
345 | k = k_end; | |
346 | else if (strncmp(istate->cache[k_start + 1]->name, prefix->buf, prefix->len) > 0) | |
347 | k = k_start + 1; | |
348 | else if (strncmp(istate->cache[k_end - 1]->name, prefix->buf, prefix->len) == 0) | |
349 | k = k_end; | |
350 | else { | |
351 | int begin = k_start; | |
352 | int end = k_end; | |
353 | assert(begin >= 0); | |
354 | while (begin < end) { | |
355 | int mid = begin + ((end - begin) >> 1); | |
356 | int cmp = strncmp(istate->cache[mid]->name, prefix->buf, prefix->len); | |
357 | if (cmp == 0) /* mid has same prefix; look in second part */ | |
358 | begin = mid + 1; | |
359 | else if (cmp > 0) /* mid is past group; look in first part */ | |
360 | end = mid; | |
361 | else | |
362 | die("cache entry out of order"); | |
363 | } | |
364 | k = begin; | |
365 | } | |
366 | ||
367 | /* | |
368 | * Recurse and process what we can of this subset [k_start, k). | |
369 | */ | |
370 | rc = handle_range_1(istate, k_start, k, dir_new, prefix, lazy_entries); | |
371 | ||
372 | strbuf_setlen(prefix, input_prefix_len); | |
373 | ||
374 | *dir_new_out = dir_new; | |
375 | return rc; | |
376 | } | |
377 | ||
378 | static int handle_range_1( | |
379 | struct index_state *istate, | |
380 | int k_start, | |
381 | int k_end, | |
382 | struct dir_entry *parent, | |
383 | struct strbuf *prefix, | |
384 | struct lazy_entry *lazy_entries) | |
385 | { | |
386 | int input_prefix_len = prefix->len; | |
387 | int k = k_start; | |
388 | ||
389 | while (k < k_end) { | |
390 | struct cache_entry *ce_k = istate->cache[k]; | |
391 | const char *name, *slash; | |
392 | ||
393 | if (prefix->len && strncmp(ce_k->name, prefix->buf, prefix->len)) | |
394 | break; | |
395 | ||
396 | name = ce_k->name + prefix->len; | |
397 | slash = strchr(name, '/'); | |
398 | ||
399 | if (slash) { | |
400 | int len = slash - name; | |
401 | int processed; | |
402 | struct dir_entry *dir_new; | |
403 | ||
404 | strbuf_add(prefix, name, len); | |
405 | processed = handle_range_dir(istate, k, k_end, parent, prefix, lazy_entries, &dir_new); | |
406 | if (processed) { | |
407 | k += processed; | |
408 | strbuf_setlen(prefix, input_prefix_len); | |
409 | continue; | |
410 | } | |
411 | ||
412 | strbuf_addch(prefix, '/'); | |
413 | processed = handle_range_1(istate, k, k_end, dir_new, prefix, lazy_entries); | |
414 | k += processed; | |
415 | strbuf_setlen(prefix, input_prefix_len); | |
416 | continue; | |
417 | } | |
418 | ||
419 | /* | |
420 | * It is too expensive to take a lock to insert "ce_k" | |
421 | * into "istate->name_hash" and increment the ref-count | |
422 | * on the "parent" dir. So we defer actually updating | |
423 | * permanent data structures until phase 2 (where we | |
424 | * can change the locking requirements) and simply | |
425 | * accumulate our current results into the lazy_entries | |
426 | * data array). | |
427 | * | |
428 | * We do not need to lock the lazy_entries array because | |
429 | * we have exclusive access to the cells in the range | |
430 | * [k_start,k_end) that this thread was given. | |
431 | */ | |
432 | lazy_entries[k].dir = parent; | |
433 | if (parent) { | |
434 | lazy_entries[k].hash_name = memihash_cont( | |
435 | parent->ent.hash, | |
436 | ce_k->name + parent->namelen, | |
437 | ce_namelen(ce_k) - parent->namelen); | |
438 | lazy_entries[k].hash_dir = parent->ent.hash; | |
439 | } else { | |
440 | lazy_entries[k].hash_name = memihash(ce_k->name, ce_namelen(ce_k)); | |
441 | } | |
442 | ||
443 | k++; | |
444 | } | |
445 | ||
446 | return k - k_start; | |
447 | } | |
448 | ||
449 | struct lazy_dir_thread_data { | |
450 | pthread_t pthread; | |
451 | struct index_state *istate; | |
452 | struct lazy_entry *lazy_entries; | |
453 | int k_start; | |
454 | int k_end; | |
455 | }; | |
456 | ||
457 | static void *lazy_dir_thread_proc(void *_data) | |
458 | { | |
459 | struct lazy_dir_thread_data *d = _data; | |
460 | struct strbuf prefix = STRBUF_INIT; | |
461 | handle_range_1(d->istate, d->k_start, d->k_end, NULL, &prefix, d->lazy_entries); | |
462 | strbuf_release(&prefix); | |
463 | return NULL; | |
464 | } | |
465 | ||
466 | struct lazy_name_thread_data { | |
467 | pthread_t pthread; | |
468 | struct index_state *istate; | |
469 | struct lazy_entry *lazy_entries; | |
470 | }; | |
471 | ||
472 | static void *lazy_name_thread_proc(void *_data) | |
473 | { | |
474 | struct lazy_name_thread_data *d = _data; | |
475 | int k; | |
476 | ||
477 | for (k = 0; k < d->istate->cache_nr; k++) { | |
478 | struct cache_entry *ce_k = d->istate->cache[k]; | |
479 | ce_k->ce_flags |= CE_HASHED; | |
480 | hashmap_entry_init(&ce_k->ent, d->lazy_entries[k].hash_name); | |
481 | hashmap_add(&d->istate->name_hash, &ce_k->ent); | |
482 | } | |
483 | ||
484 | return NULL; | |
485 | } | |
486 | ||
487 | static inline void lazy_update_dir_ref_counts( | |
488 | struct index_state *istate, | |
489 | struct lazy_entry *lazy_entries) | |
490 | { | |
491 | int k; | |
492 | ||
493 | for (k = 0; k < istate->cache_nr; k++) { | |
494 | if (lazy_entries[k].dir) | |
495 | lazy_entries[k].dir->nr++; | |
496 | } | |
497 | } | |
498 | ||
499 | static void threaded_lazy_init_name_hash( | |
500 | struct index_state *istate) | |
501 | { | |
502 | int err; | |
503 | int nr_each; | |
504 | int k_start; | |
505 | int t; | |
506 | struct lazy_entry *lazy_entries; | |
507 | struct lazy_dir_thread_data *td_dir; | |
508 | struct lazy_name_thread_data *td_name; | |
509 | ||
510 | if (!HAVE_THREADS) | |
511 | return; | |
512 | ||
513 | k_start = 0; | |
514 | nr_each = DIV_ROUND_UP(istate->cache_nr, lazy_nr_dir_threads); | |
515 | ||
516 | lazy_entries = xcalloc(istate->cache_nr, sizeof(struct lazy_entry)); | |
517 | td_dir = xcalloc(lazy_nr_dir_threads, sizeof(struct lazy_dir_thread_data)); | |
518 | td_name = xcalloc(1, sizeof(struct lazy_name_thread_data)); | |
519 | ||
520 | init_dir_mutex(); | |
521 | ||
522 | /* | |
523 | * Phase 1: | |
524 | * Build "istate->dir_hash" using n "dir" threads (and a read-only index). | |
525 | */ | |
526 | for (t = 0; t < lazy_nr_dir_threads; t++) { | |
527 | struct lazy_dir_thread_data *td_dir_t = td_dir + t; | |
528 | td_dir_t->istate = istate; | |
529 | td_dir_t->lazy_entries = lazy_entries; | |
530 | td_dir_t->k_start = k_start; | |
531 | k_start += nr_each; | |
532 | if (k_start > istate->cache_nr) | |
533 | k_start = istate->cache_nr; | |
534 | td_dir_t->k_end = k_start; | |
535 | err = pthread_create(&td_dir_t->pthread, NULL, lazy_dir_thread_proc, td_dir_t); | |
536 | if (err) | |
537 | die(_("unable to create lazy_dir thread: %s"), strerror(err)); | |
538 | } | |
539 | for (t = 0; t < lazy_nr_dir_threads; t++) { | |
540 | struct lazy_dir_thread_data *td_dir_t = td_dir + t; | |
541 | if (pthread_join(td_dir_t->pthread, NULL)) | |
542 | die("unable to join lazy_dir_thread"); | |
543 | } | |
544 | ||
545 | /* | |
546 | * Phase 2: | |
547 | * Iterate over all index entries and add them to the "istate->name_hash" | |
548 | * using a single "name" background thread. | |
549 | * (Testing showed it wasn't worth running more than 1 thread for this.) | |
550 | * | |
551 | * Meanwhile, finish updating the parent directory ref-counts for each | |
552 | * index entry using the current thread. (This step is very fast and | |
553 | * doesn't need threading.) | |
554 | */ | |
555 | td_name->istate = istate; | |
556 | td_name->lazy_entries = lazy_entries; | |
557 | err = pthread_create(&td_name->pthread, NULL, lazy_name_thread_proc, td_name); | |
558 | if (err) | |
559 | die(_("unable to create lazy_name thread: %s"), strerror(err)); | |
560 | ||
561 | lazy_update_dir_ref_counts(istate, lazy_entries); | |
562 | ||
563 | err = pthread_join(td_name->pthread, NULL); | |
564 | if (err) | |
565 | die(_("unable to join lazy_name thread: %s"), strerror(err)); | |
566 | ||
567 | cleanup_dir_mutex(); | |
568 | ||
569 | free(td_name); | |
570 | free(td_dir); | |
571 | free(lazy_entries); | |
572 | } | |
573 | ||
574 | static void lazy_init_name_hash(struct index_state *istate) | |
575 | { | |
576 | ||
577 | if (istate->name_hash_initialized) | |
578 | return; | |
579 | trace_performance_enter(); | |
580 | hashmap_init(&istate->name_hash, cache_entry_cmp, NULL, istate->cache_nr); | |
581 | hashmap_init(&istate->dir_hash, dir_entry_cmp, NULL, istate->cache_nr); | |
582 | ||
583 | if (lookup_lazy_params(istate)) { | |
584 | /* | |
585 | * Disable item counting and automatic rehashing because | |
586 | * we do per-chain (mod n) locking rather than whole hashmap | |
587 | * locking and we need to prevent the table-size from changing | |
588 | * and bucket items from being redistributed. | |
589 | */ | |
590 | hashmap_disable_item_counting(&istate->dir_hash); | |
591 | threaded_lazy_init_name_hash(istate); | |
592 | hashmap_enable_item_counting(&istate->dir_hash); | |
593 | } else { | |
594 | int nr; | |
595 | for (nr = 0; nr < istate->cache_nr; nr++) | |
596 | hash_index_entry(istate, istate->cache[nr]); | |
597 | } | |
598 | ||
599 | istate->name_hash_initialized = 1; | |
600 | trace_performance_leave("initialize name hash"); | |
601 | } | |
602 | ||
603 | /* | |
604 | * A test routine for t/helper/ sources. | |
605 | * | |
606 | * Returns the number of threads used or 0 when | |
607 | * the non-threaded code path was used. | |
608 | * | |
609 | * Requesting threading WILL NOT override guards | |
610 | * in lookup_lazy_params(). | |
611 | */ | |
612 | int test_lazy_init_name_hash(struct index_state *istate, int try_threaded) | |
613 | { | |
614 | lazy_nr_dir_threads = 0; | |
615 | lazy_try_threaded = try_threaded; | |
616 | ||
617 | lazy_init_name_hash(istate); | |
618 | ||
619 | return lazy_nr_dir_threads; | |
620 | } | |
621 | ||
622 | void add_name_hash(struct index_state *istate, struct cache_entry *ce) | |
623 | { | |
624 | if (istate->name_hash_initialized) | |
625 | hash_index_entry(istate, ce); | |
626 | } | |
627 | ||
628 | void remove_name_hash(struct index_state *istate, struct cache_entry *ce) | |
629 | { | |
630 | if (!istate->name_hash_initialized || !(ce->ce_flags & CE_HASHED)) | |
631 | return; | |
632 | ce->ce_flags &= ~CE_HASHED; | |
633 | hashmap_remove(&istate->name_hash, &ce->ent, ce); | |
634 | ||
635 | if (ignore_case) | |
636 | remove_dir_entry(istate, ce); | |
637 | } | |
638 | ||
639 | static int slow_same_name(const char *name1, int len1, const char *name2, int len2) | |
640 | { | |
641 | if (len1 != len2) | |
642 | return 0; | |
643 | ||
644 | while (len1) { | |
645 | unsigned char c1 = *name1++; | |
646 | unsigned char c2 = *name2++; | |
647 | len1--; | |
648 | if (c1 != c2) { | |
649 | c1 = toupper(c1); | |
650 | c2 = toupper(c2); | |
651 | if (c1 != c2) | |
652 | return 0; | |
653 | } | |
654 | } | |
655 | return 1; | |
656 | } | |
657 | ||
658 | static int same_name(const struct cache_entry *ce, const char *name, int namelen, int icase) | |
659 | { | |
660 | int len = ce_namelen(ce); | |
661 | ||
662 | /* | |
663 | * Always do exact compare, even if we want a case-ignoring comparison; | |
664 | * we do the quick exact one first, because it will be the common case. | |
665 | */ | |
666 | if (len == namelen && !memcmp(name, ce->name, len)) | |
667 | return 1; | |
668 | ||
669 | if (!icase) | |
670 | return 0; | |
671 | ||
672 | return slow_same_name(name, namelen, ce->name, len); | |
673 | } | |
674 | ||
675 | int index_dir_exists(struct index_state *istate, const char *name, int namelen) | |
676 | { | |
677 | struct dir_entry *dir; | |
678 | ||
679 | lazy_init_name_hash(istate); | |
680 | dir = find_dir_entry(istate, name, namelen); | |
681 | return dir && dir->nr; | |
682 | } | |
683 | ||
684 | void adjust_dirname_case(struct index_state *istate, char *name) | |
685 | { | |
686 | const char *startPtr = name; | |
687 | const char *ptr = startPtr; | |
688 | ||
689 | lazy_init_name_hash(istate); | |
690 | while (*ptr) { | |
691 | while (*ptr && *ptr != '/') | |
692 | ptr++; | |
693 | ||
694 | if (*ptr == '/') { | |
695 | struct dir_entry *dir; | |
696 | ||
697 | dir = find_dir_entry(istate, name, ptr - name); | |
698 | if (dir) { | |
699 | memcpy((void *)startPtr, dir->name + (startPtr - name), ptr - startPtr); | |
700 | startPtr = ptr + 1; | |
701 | } | |
702 | ptr++; | |
703 | } | |
704 | } | |
705 | } | |
706 | ||
707 | struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int icase) | |
708 | { | |
709 | struct cache_entry *ce; | |
710 | unsigned int hash = memihash(name, namelen); | |
711 | ||
712 | lazy_init_name_hash(istate); | |
713 | ||
714 | ce = hashmap_get_entry_from_hash(&istate->name_hash, hash, NULL, | |
715 | struct cache_entry, ent); | |
716 | hashmap_for_each_entry_from(&istate->name_hash, ce, ent) { | |
717 | if (same_name(ce, name, namelen, icase)) | |
718 | return ce; | |
719 | } | |
720 | return NULL; | |
721 | } | |
722 | ||
723 | void free_name_hash(struct index_state *istate) | |
724 | { | |
725 | if (!istate->name_hash_initialized) | |
726 | return; | |
727 | istate->name_hash_initialized = 0; | |
728 | ||
729 | hashmap_free(&istate->name_hash); | |
730 | hashmap_free_entries(&istate->dir_hash, struct dir_entry, ent); | |
731 | } |