clone: initialize atexit cleanup handler earlier
[git.git] / cache-tree.c
blob7fa524a11323621d24c352b0a1108ae953a60cf5
1 #include "cache.h"
2 #include "tree.h"
3 #include "tree-walk.h"
4 #include "cache-tree.h"
6 #ifndef DEBUG
7 #define DEBUG 0
8 #endif
10 struct cache_tree *cache_tree(void)
12 struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
13 it->entry_count = -1;
14 return it;
17 void cache_tree_free(struct cache_tree **it_p)
19 int i;
20 struct cache_tree *it = *it_p;
22 if (!it)
23 return;
24 for (i = 0; i < it->subtree_nr; i++)
25 if (it->down[i]) {
26 cache_tree_free(&it->down[i]->cache_tree);
27 free(it->down[i]);
29 free(it->down);
30 free(it);
31 *it_p = NULL;
34 static int subtree_name_cmp(const char *one, int onelen,
35 const char *two, int twolen)
37 if (onelen < twolen)
38 return -1;
39 if (twolen < onelen)
40 return 1;
41 return memcmp(one, two, onelen);
44 static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
46 struct cache_tree_sub **down = it->down;
47 int lo, hi;
48 lo = 0;
49 hi = it->subtree_nr;
50 while (lo < hi) {
51 int mi = (lo + hi) / 2;
52 struct cache_tree_sub *mdl = down[mi];
53 int cmp = subtree_name_cmp(path, pathlen,
54 mdl->name, mdl->namelen);
55 if (!cmp)
56 return mi;
57 if (cmp < 0)
58 hi = mi;
59 else
60 lo = mi + 1;
62 return -lo-1;
65 static struct cache_tree_sub *find_subtree(struct cache_tree *it,
66 const char *path,
67 int pathlen,
68 int create)
70 struct cache_tree_sub *down;
71 int pos = subtree_pos(it, path, pathlen);
72 if (0 <= pos)
73 return it->down[pos];
74 if (!create)
75 return NULL;
77 pos = -pos-1;
78 ALLOC_GROW(it->down, it->subtree_nr + 1, it->subtree_alloc);
79 it->subtree_nr++;
81 down = xmalloc(sizeof(*down) + pathlen + 1);
82 down->cache_tree = NULL;
83 down->namelen = pathlen;
84 memcpy(down->name, path, pathlen);
85 down->name[pathlen] = 0;
87 if (pos < it->subtree_nr)
88 memmove(it->down + pos + 1,
89 it->down + pos,
90 sizeof(down) * (it->subtree_nr - pos - 1));
91 it->down[pos] = down;
92 return down;
95 struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
97 int pathlen = strlen(path);
98 return find_subtree(it, path, pathlen, 1);
101 void cache_tree_invalidate_path(struct cache_tree *it, const char *path)
103 /* a/b/c
104 * ==> invalidate self
105 * ==> find "a", have it invalidate "b/c"
107 * ==> invalidate self
108 * ==> if "a" exists as a subtree, remove it.
110 const char *slash;
111 int namelen;
112 struct cache_tree_sub *down;
114 #if DEBUG
115 fprintf(stderr, "cache-tree invalidate <%s>\n", path);
116 #endif
118 if (!it)
119 return;
120 slash = strchrnul(path, '/');
121 namelen = slash - path;
122 it->entry_count = -1;
123 if (!*slash) {
124 int pos;
125 pos = subtree_pos(it, path, namelen);
126 if (0 <= pos) {
127 cache_tree_free(&it->down[pos]->cache_tree);
128 free(it->down[pos]);
129 /* 0 1 2 3 4 5
130 * ^ ^subtree_nr = 6
131 * pos
132 * move 4 and 5 up one place (2 entries)
133 * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
135 memmove(it->down+pos, it->down+pos+1,
136 sizeof(struct cache_tree_sub *) *
137 (it->subtree_nr - pos - 1));
138 it->subtree_nr--;
140 return;
142 down = find_subtree(it, path, namelen, 0);
143 if (down)
144 cache_tree_invalidate_path(down->cache_tree, slash + 1);
147 static int verify_cache(const struct cache_entry * const *cache,
148 int entries, int flags)
150 int i, funny;
151 int silent = flags & WRITE_TREE_SILENT;
153 /* Verify that the tree is merged */
154 funny = 0;
155 for (i = 0; i < entries; i++) {
156 const struct cache_entry *ce = cache[i];
157 if (ce_stage(ce)) {
158 if (silent)
159 return -1;
160 if (10 < ++funny) {
161 fprintf(stderr, "...\n");
162 break;
164 fprintf(stderr, "%s: unmerged (%s)\n",
165 ce->name, sha1_to_hex(ce->sha1));
168 if (funny)
169 return -1;
171 /* Also verify that the cache does not have path and path/file
172 * at the same time. At this point we know the cache has only
173 * stage 0 entries.
175 funny = 0;
176 for (i = 0; i < entries - 1; i++) {
177 /* path/file always comes after path because of the way
178 * the cache is sorted. Also path can appear only once,
179 * which means conflicting one would immediately follow.
181 const char *this_name = cache[i]->name;
182 const char *next_name = cache[i+1]->name;
183 int this_len = strlen(this_name);
184 if (this_len < strlen(next_name) &&
185 strncmp(this_name, next_name, this_len) == 0 &&
186 next_name[this_len] == '/') {
187 if (10 < ++funny) {
188 fprintf(stderr, "...\n");
189 break;
191 fprintf(stderr, "You have both %s and %s\n",
192 this_name, next_name);
195 if (funny)
196 return -1;
197 return 0;
200 static void discard_unused_subtrees(struct cache_tree *it)
202 struct cache_tree_sub **down = it->down;
203 int nr = it->subtree_nr;
204 int dst, src;
205 for (dst = src = 0; src < nr; src++) {
206 struct cache_tree_sub *s = down[src];
207 if (s->used)
208 down[dst++] = s;
209 else {
210 cache_tree_free(&s->cache_tree);
211 free(s);
212 it->subtree_nr--;
217 int cache_tree_fully_valid(struct cache_tree *it)
219 int i;
220 if (!it)
221 return 0;
222 if (it->entry_count < 0 || !has_sha1_file(it->sha1))
223 return 0;
224 for (i = 0; i < it->subtree_nr; i++) {
225 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
226 return 0;
228 return 1;
231 static int update_one(struct cache_tree *it,
232 const struct cache_entry * const *cache,
233 int entries,
234 const char *base,
235 int baselen,
236 int *skip_count,
237 int flags)
239 struct strbuf buffer;
240 int missing_ok = flags & WRITE_TREE_MISSING_OK;
241 int dryrun = flags & WRITE_TREE_DRY_RUN;
242 int to_invalidate = 0;
243 int i;
245 *skip_count = 0;
247 if (0 <= it->entry_count && has_sha1_file(it->sha1))
248 return it->entry_count;
251 * We first scan for subtrees and update them; we start by
252 * marking existing subtrees -- the ones that are unmarked
253 * should not be in the result.
255 for (i = 0; i < it->subtree_nr; i++)
256 it->down[i]->used = 0;
259 * Find the subtrees and update them.
261 i = 0;
262 while (i < entries) {
263 const struct cache_entry *ce = cache[i];
264 struct cache_tree_sub *sub;
265 const char *path, *slash;
266 int pathlen, sublen, subcnt, subskip;
268 path = ce->name;
269 pathlen = ce_namelen(ce);
270 if (pathlen <= baselen || memcmp(base, path, baselen))
271 break; /* at the end of this level */
273 slash = strchr(path + baselen, '/');
274 if (!slash) {
275 i++;
276 continue;
279 * a/bbb/c (base = a/, slash = /c)
280 * ==>
281 * path+baselen = bbb/c, sublen = 3
283 sublen = slash - (path + baselen);
284 sub = find_subtree(it, path + baselen, sublen, 1);
285 if (!sub->cache_tree)
286 sub->cache_tree = cache_tree();
287 subcnt = update_one(sub->cache_tree,
288 cache + i, entries - i,
289 path,
290 baselen + sublen + 1,
291 &subskip,
292 flags);
293 if (subcnt < 0)
294 return subcnt;
295 i += subcnt;
296 sub->count = subcnt; /* to be used in the next loop */
297 *skip_count += subskip;
298 sub->used = 1;
301 discard_unused_subtrees(it);
304 * Then write out the tree object for this level.
306 strbuf_init(&buffer, 8192);
308 i = 0;
309 while (i < entries) {
310 const struct cache_entry *ce = cache[i];
311 struct cache_tree_sub *sub;
312 const char *path, *slash;
313 int pathlen, entlen;
314 const unsigned char *sha1;
315 unsigned mode;
317 path = ce->name;
318 pathlen = ce_namelen(ce);
319 if (pathlen <= baselen || memcmp(base, path, baselen))
320 break; /* at the end of this level */
322 slash = strchr(path + baselen, '/');
323 if (slash) {
324 entlen = slash - (path + baselen);
325 sub = find_subtree(it, path + baselen, entlen, 0);
326 if (!sub)
327 die("cache-tree.c: '%.*s' in '%s' not found",
328 entlen, path + baselen, path);
329 i += sub->count;
330 sha1 = sub->cache_tree->sha1;
331 mode = S_IFDIR;
332 if (sub->cache_tree->entry_count < 0)
333 to_invalidate = 1;
335 else {
336 sha1 = ce->sha1;
337 mode = ce->ce_mode;
338 entlen = pathlen - baselen;
339 i++;
341 if (mode != S_IFGITLINK && !missing_ok && !has_sha1_file(sha1)) {
342 strbuf_release(&buffer);
343 return error("invalid object %06o %s for '%.*s'",
344 mode, sha1_to_hex(sha1), entlen+baselen, path);
348 * CE_REMOVE entries are removed before the index is
349 * written to disk. Skip them to remain consistent
350 * with the future on-disk index.
352 if (ce->ce_flags & CE_REMOVE) {
353 *skip_count = *skip_count + 1;
354 continue;
358 * CE_INTENT_TO_ADD entries exist on on-disk index but
359 * they are not part of generated trees. Invalidate up
360 * to root to force cache-tree users to read elsewhere.
362 if (ce->ce_flags & CE_INTENT_TO_ADD) {
363 to_invalidate = 1;
364 continue;
367 strbuf_grow(&buffer, entlen + 100);
368 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
369 strbuf_add(&buffer, sha1, 20);
371 #if DEBUG
372 fprintf(stderr, "cache-tree update-one %o %.*s\n",
373 mode, entlen, path + baselen);
374 #endif
377 if (dryrun)
378 hash_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
379 else if (write_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1)) {
380 strbuf_release(&buffer);
381 return -1;
384 strbuf_release(&buffer);
385 it->entry_count = to_invalidate ? -1 : i - *skip_count;
386 #if DEBUG
387 fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
388 it->entry_count, it->subtree_nr,
389 sha1_to_hex(it->sha1));
390 #endif
391 return i;
394 int cache_tree_update(struct cache_tree *it,
395 const struct cache_entry * const *cache,
396 int entries,
397 int flags)
399 int i, skip;
400 i = verify_cache(cache, entries, flags);
401 if (i)
402 return i;
403 i = update_one(it, cache, entries, "", 0, &skip, flags);
404 if (i < 0)
405 return i;
406 return 0;
409 static void write_one(struct strbuf *buffer, struct cache_tree *it,
410 const char *path, int pathlen)
412 int i;
414 /* One "cache-tree" entry consists of the following:
415 * path (NUL terminated)
416 * entry_count, subtree_nr ("%d %d\n")
417 * tree-sha1 (missing if invalid)
418 * subtree_nr "cache-tree" entries for subtrees.
420 strbuf_grow(buffer, pathlen + 100);
421 strbuf_add(buffer, path, pathlen);
422 strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
424 #if DEBUG
425 if (0 <= it->entry_count)
426 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
427 pathlen, path, it->entry_count, it->subtree_nr,
428 sha1_to_hex(it->sha1));
429 else
430 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
431 pathlen, path, it->subtree_nr);
432 #endif
434 if (0 <= it->entry_count) {
435 strbuf_add(buffer, it->sha1, 20);
437 for (i = 0; i < it->subtree_nr; i++) {
438 struct cache_tree_sub *down = it->down[i];
439 if (i) {
440 struct cache_tree_sub *prev = it->down[i-1];
441 if (subtree_name_cmp(down->name, down->namelen,
442 prev->name, prev->namelen) <= 0)
443 die("fatal - unsorted cache subtree");
445 write_one(buffer, down->cache_tree, down->name, down->namelen);
449 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
451 write_one(sb, root, "", 0);
454 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
456 const char *buf = *buffer;
457 unsigned long size = *size_p;
458 const char *cp;
459 char *ep;
460 struct cache_tree *it;
461 int i, subtree_nr;
463 it = NULL;
464 /* skip name, but make sure name exists */
465 while (size && *buf) {
466 size--;
467 buf++;
469 if (!size)
470 goto free_return;
471 buf++; size--;
472 it = cache_tree();
474 cp = buf;
475 it->entry_count = strtol(cp, &ep, 10);
476 if (cp == ep)
477 goto free_return;
478 cp = ep;
479 subtree_nr = strtol(cp, &ep, 10);
480 if (cp == ep)
481 goto free_return;
482 while (size && *buf && *buf != '\n') {
483 size--;
484 buf++;
486 if (!size)
487 goto free_return;
488 buf++; size--;
489 if (0 <= it->entry_count) {
490 if (size < 20)
491 goto free_return;
492 hashcpy(it->sha1, (const unsigned char*)buf);
493 buf += 20;
494 size -= 20;
497 #if DEBUG
498 if (0 <= it->entry_count)
499 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
500 *buffer, it->entry_count, subtree_nr,
501 sha1_to_hex(it->sha1));
502 else
503 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
504 *buffer, subtree_nr);
505 #endif
508 * Just a heuristic -- we do not add directories that often but
509 * we do not want to have to extend it immediately when we do,
510 * hence +2.
512 it->subtree_alloc = subtree_nr + 2;
513 it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
514 for (i = 0; i < subtree_nr; i++) {
515 /* read each subtree */
516 struct cache_tree *sub;
517 struct cache_tree_sub *subtree;
518 const char *name = buf;
520 sub = read_one(&buf, &size);
521 if (!sub)
522 goto free_return;
523 subtree = cache_tree_sub(it, name);
524 subtree->cache_tree = sub;
526 if (subtree_nr != it->subtree_nr)
527 die("cache-tree: internal error");
528 *buffer = buf;
529 *size_p = size;
530 return it;
532 free_return:
533 cache_tree_free(&it);
534 return NULL;
537 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
539 if (buffer[0])
540 return NULL; /* not the whole tree */
541 return read_one(&buffer, &size);
544 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
546 if (!it)
547 return NULL;
548 while (*path) {
549 const char *slash;
550 struct cache_tree_sub *sub;
552 slash = strchrnul(path, '/');
554 * Between path and slash is the name of the subtree
555 * to look for.
557 sub = find_subtree(it, path, slash - path, 0);
558 if (!sub)
559 return NULL;
560 it = sub->cache_tree;
562 path = slash;
563 while (*path == '/')
564 path++;
566 return it;
569 int write_cache_as_tree(unsigned char *sha1, int flags, const char *prefix)
571 int entries, was_valid, newfd;
572 struct lock_file *lock_file;
575 * We can't free this memory, it becomes part of a linked list
576 * parsed atexit()
578 lock_file = xcalloc(1, sizeof(struct lock_file));
580 newfd = hold_locked_index(lock_file, 1);
582 entries = read_cache();
583 if (entries < 0)
584 return WRITE_TREE_UNREADABLE_INDEX;
585 if (flags & WRITE_TREE_IGNORE_CACHE_TREE)
586 cache_tree_free(&(active_cache_tree));
588 if (!active_cache_tree)
589 active_cache_tree = cache_tree();
591 was_valid = cache_tree_fully_valid(active_cache_tree);
592 if (!was_valid) {
593 if (cache_tree_update(active_cache_tree,
594 (const struct cache_entry * const *)active_cache,
595 active_nr, flags) < 0)
596 return WRITE_TREE_UNMERGED_INDEX;
597 if (0 <= newfd) {
598 if (!write_cache(newfd, active_cache, active_nr) &&
599 !commit_lock_file(lock_file))
600 newfd = -1;
602 /* Not being able to write is fine -- we are only interested
603 * in updating the cache-tree part, and if the next caller
604 * ends up using the old index with unupdated cache-tree part
605 * it misses the work we did here, but that is just a
606 * performance penalty and not a big deal.
610 if (prefix) {
611 struct cache_tree *subtree =
612 cache_tree_find(active_cache_tree, prefix);
613 if (!subtree)
614 return WRITE_TREE_PREFIX_ERROR;
615 hashcpy(sha1, subtree->sha1);
617 else
618 hashcpy(sha1, active_cache_tree->sha1);
620 if (0 <= newfd)
621 rollback_lock_file(lock_file);
623 return 0;
626 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
628 struct tree_desc desc;
629 struct name_entry entry;
630 int cnt;
632 hashcpy(it->sha1, tree->object.sha1);
633 init_tree_desc(&desc, tree->buffer, tree->size);
634 cnt = 0;
635 while (tree_entry(&desc, &entry)) {
636 if (!S_ISDIR(entry.mode))
637 cnt++;
638 else {
639 struct cache_tree_sub *sub;
640 struct tree *subtree = lookup_tree(entry.sha1);
641 if (!subtree->object.parsed)
642 parse_tree(subtree);
643 sub = cache_tree_sub(it, entry.path);
644 sub->cache_tree = cache_tree();
645 prime_cache_tree_rec(sub->cache_tree, subtree);
646 cnt += sub->cache_tree->entry_count;
649 it->entry_count = cnt;
652 void prime_cache_tree(struct cache_tree **it, struct tree *tree)
654 cache_tree_free(it);
655 *it = cache_tree();
656 prime_cache_tree_rec(*it, tree);
660 * find the cache_tree that corresponds to the current level without
661 * exploding the full path into textual form. The root of the
662 * cache tree is given as "root", and our current level is "info".
663 * (1) When at root level, info->prev is NULL, so it is "root" itself.
664 * (2) Otherwise, find the cache_tree that corresponds to one level
665 * above us, and find ourselves in there.
667 static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
668 struct traverse_info *info)
670 struct cache_tree *our_parent;
672 if (!info->prev)
673 return root;
674 our_parent = find_cache_tree_from_traversal(root, info->prev);
675 return cache_tree_find(our_parent, info->name.path);
678 int cache_tree_matches_traversal(struct cache_tree *root,
679 struct name_entry *ent,
680 struct traverse_info *info)
682 struct cache_tree *it;
684 it = find_cache_tree_from_traversal(root, info);
685 it = cache_tree_find(it, ent->path);
686 if (it && it->entry_count > 0 && !hashcmp(ent->sha1, it->sha1))
687 return it->entry_count;
688 return 0;
691 int update_main_cache_tree(int flags)
693 if (!the_index.cache_tree)
694 the_index.cache_tree = cache_tree();
695 return cache_tree_update(the_index.cache_tree,
696 (const struct cache_entry * const *)the_index.cache,
697 the_index.cache_nr, flags);