1#include "cache.h"
2#include "lockfile.h"
3#include "tree.h"
4#include "tree-walk.h"
5#include "cache-tree.h"
6#ifndef DEBUG
8#define DEBUG 0
9#endif
10struct cache_tree *cache_tree(void)
12{
13 struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
14 it->entry_count = -1;
15 return it;
16}
17void cache_tree_free(struct cache_tree **it_p)
19{
20 int i;
21 struct cache_tree *it = *it_p;
22 if (!it)
24 return;
25 for (i = 0; i < it->subtree_nr; i++)
26 if (it->down[i]) {
27 cache_tree_free(&it->down[i]->cache_tree);
28 free(it->down[i]);
29 }
30 free(it->down);
31 free(it);
32 *it_p = NULL;
33}
34static int subtree_name_cmp(const char *one, int onelen,
36 const char *two, int twolen)
37{
38 if (onelen < twolen)
39 return -1;
40 if (twolen < onelen)
41 return 1;
42 return memcmp(one, two, onelen);
43}
44static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
46{
47 struct cache_tree_sub **down = it->down;
48 int lo, hi;
49 lo = 0;
50 hi = it->subtree_nr;
51 while (lo < hi) {
52 int mi = (lo + hi) / 2;
53 struct cache_tree_sub *mdl = down[mi];
54 int cmp = subtree_name_cmp(path, pathlen,
55 mdl->name, mdl->namelen);
56 if (!cmp)
57 return mi;
58 if (cmp < 0)
59 hi = mi;
60 else
61 lo = mi + 1;
62 }
63 return -lo-1;
64}
65static struct cache_tree_sub *find_subtree(struct cache_tree *it,
67 const char *path,
68 int pathlen,
69 int create)
70{
71 struct cache_tree_sub *down;
72 int pos = subtree_pos(it, path, pathlen);
73 if (0 <= pos)
74 return it->down[pos];
75 if (!create)
76 return NULL;
77 pos = -pos-1;
79 ALLOC_GROW(it->down, it->subtree_nr + 1, it->subtree_alloc);
80 it->subtree_nr++;
81 FLEX_ALLOC_MEM(down, name, path, pathlen);
83 down->cache_tree = NULL;
84 down->namelen = pathlen;
85 if (pos < it->subtree_nr)
87 memmove(it->down + pos + 1,
88 it->down + pos,
89 sizeof(down) * (it->subtree_nr - pos - 1));
90 it->down[pos] = down;
91 return down;
92}
93struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
95{
96 int pathlen = strlen(path);
97 return find_subtree(it, path, pathlen, 1);
98}
99static int do_invalidate_path(struct cache_tree *it, const char *path)
101{
102 /* a/b/c
103 * ==> invalidate self
104 * ==> find "a", have it invalidate "b/c"
105 * a
106 * ==> invalidate self
107 * ==> if "a" exists as a subtree, remove it.
108 */
109 const char *slash;
110 int namelen;
111 struct cache_tree_sub *down;
112#if DEBUG
114 fprintf(stderr, "cache-tree invalidate <%s>\n", path);
115#endif
116 if (!it)
118 return 0;
119 slash = strchrnul(path, '/');
120 namelen = slash - path;
121 it->entry_count = -1;
122 if (!*slash) {
123 int pos;
124 pos = subtree_pos(it, path, namelen);
125 if (0 <= pos) {
126 cache_tree_free(&it->down[pos]->cache_tree);
127 free(it->down[pos]);
128 /* 0 1 2 3 4 5
129 * ^ ^subtree_nr = 6
130 * pos
131 * move 4 and 5 up one place (2 entries)
132 * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
133 */
134 MOVE_ARRAY(it->down + pos, it->down + pos + 1,
135 it->subtree_nr - pos - 1);
136 it->subtree_nr--;
137 }
138 return 1;
139 }
140 down = find_subtree(it, path, namelen, 0);
141 if (down)
142 do_invalidate_path(down->cache_tree, slash + 1);
143 return 1;
144}
145void cache_tree_invalidate_path(struct index_state *istate, const char *path)
147{
148 if (do_invalidate_path(istate->cache_tree, path))
149 istate->cache_changed |= CACHE_TREE_CHANGED;
150}
151static int verify_cache(struct cache_entry **cache,
153 int entries, int flags)
154{
155 int i, funny;
156 int silent = flags & WRITE_TREE_SILENT;
157 /* Verify that the tree is merged */
159 funny = 0;
160 for (i = 0; i < entries; i++) {
161 const struct cache_entry *ce = cache[i];
162 if (ce_stage(ce)) {
163 if (silent)
164 return -1;
165 if (10 < ++funny) {
166 fprintf(stderr, "...\n");
167 break;
168 }
169 fprintf(stderr, "%s: unmerged (%s)\n",
170 ce->name, oid_to_hex(&ce->oid));
171 }
172 }
173 if (funny)
174 return -1;
175 /* Also verify that the cache does not have path and path/file
177 * at the same time. At this point we know the cache has only
178 * stage 0 entries.
179 */
180 funny = 0;
181 for (i = 0; i < entries - 1; i++) {
182 /* path/file always comes after path because of the way
183 * the cache is sorted. Also path can appear only once,
184 * which means conflicting one would immediately follow.
185 */
186 const char *this_name = cache[i]->name;
187 const char *next_name = cache[i+1]->name;
188 int this_len = strlen(this_name);
189 if (this_len < strlen(next_name) &&
190 strncmp(this_name, next_name, this_len) == 0 &&
191 next_name[this_len] == '/') {
192 if (10 < ++funny) {
193 fprintf(stderr, "...\n");
194 break;
195 }
196 fprintf(stderr, "You have both %s and %s\n",
197 this_name, next_name);
198 }
199 }
200 if (funny)
201 return -1;
202 return 0;
203}
204static void discard_unused_subtrees(struct cache_tree *it)
206{
207 struct cache_tree_sub **down = it->down;
208 int nr = it->subtree_nr;
209 int dst, src;
210 for (dst = src = 0; src < nr; src++) {
211 struct cache_tree_sub *s = down[src];
212 if (s->used)
213 down[dst++] = s;
214 else {
215 cache_tree_free(&s->cache_tree);
216 free(s);
217 it->subtree_nr--;
218 }
219 }
220}
221int cache_tree_fully_valid(struct cache_tree *it)
223{
224 int i;
225 if (!it)
226 return 0;
227 if (it->entry_count < 0 || !has_sha1_file(it->oid.hash))
228 return 0;
229 for (i = 0; i < it->subtree_nr; i++) {
230 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
231 return 0;
232 }
233 return 1;
234}
235static int update_one(struct cache_tree *it,
237 struct cache_entry **cache,
238 int entries,
239 const char *base,
240 int baselen,
241 int *skip_count,
242 int flags)
243{
244 struct strbuf buffer;
245 int missing_ok = flags & WRITE_TREE_MISSING_OK;
246 int dryrun = flags & WRITE_TREE_DRY_RUN;
247 int repair = flags & WRITE_TREE_REPAIR;
248 int to_invalidate = 0;
249 int i;
250 assert(!(dryrun && repair));
252 *skip_count = 0;
254 if (0 <= it->entry_count && has_sha1_file(it->oid.hash))
256 return it->entry_count;
257 /*
259 * We first scan for subtrees and update them; we start by
260 * marking existing subtrees -- the ones that are unmarked
261 * should not be in the result.
262 */
263 for (i = 0; i < it->subtree_nr; i++)
264 it->down[i]->used = 0;
265 /*
267 * Find the subtrees and update them.
268 */
269 i = 0;
270 while (i < entries) {
271 const struct cache_entry *ce = cache[i];
272 struct cache_tree_sub *sub;
273 const char *path, *slash;
274 int pathlen, sublen, subcnt, subskip;
275 path = ce->name;
277 pathlen = ce_namelen(ce);
278 if (pathlen <= baselen || memcmp(base, path, baselen))
279 break; /* at the end of this level */
280 slash = strchr(path + baselen, '/');
282 if (!slash) {
283 i++;
284 continue;
285 }
286 /*
287 * a/bbb/c (base = a/, slash = /c)
288 * ==>
289 * path+baselen = bbb/c, sublen = 3
290 */
291 sublen = slash - (path + baselen);
292 sub = find_subtree(it, path + baselen, sublen, 1);
293 if (!sub->cache_tree)
294 sub->cache_tree = cache_tree();
295 subcnt = update_one(sub->cache_tree,
296 cache + i, entries - i,
297 path,
298 baselen + sublen + 1,
299 &subskip,
300 flags);
301 if (subcnt < 0)
302 return subcnt;
303 if (!subcnt)
304 die("index cache-tree records empty sub-tree");
305 i += subcnt;
306 sub->count = subcnt; /* to be used in the next loop */
307 *skip_count += subskip;
308 sub->used = 1;
309 }
310 discard_unused_subtrees(it);
312 /*
314 * Then write out the tree object for this level.
315 */
316 strbuf_init(&buffer, 8192);
317 i = 0;
319 while (i < entries) {
320 const struct cache_entry *ce = cache[i];
321 struct cache_tree_sub *sub = NULL;
322 const char *path, *slash;
323 int pathlen, entlen;
324 const unsigned char *sha1;
325 unsigned mode;
326 int expected_missing = 0;
327 int contains_ita = 0;
328 path = ce->name;
330 pathlen = ce_namelen(ce);
331 if (pathlen <= baselen || memcmp(base, path, baselen))
332 break; /* at the end of this level */
333 slash = strchr(path + baselen, '/');
335 if (slash) {
336 entlen = slash - (path + baselen);
337 sub = find_subtree(it, path + baselen, entlen, 0);
338 if (!sub)
339 die("cache-tree.c: '%.*s' in '%s' not found",
340 entlen, path + baselen, path);
341 i += sub->count;
342 sha1 = sub->cache_tree->oid.hash;
343 mode = S_IFDIR;
344 contains_ita = sub->cache_tree->entry_count < 0;
345 if (contains_ita) {
346 to_invalidate = 1;
347 expected_missing = 1;
348 }
349 }
350 else {
351 sha1 = ce->oid.hash;
352 mode = ce->ce_mode;
353 entlen = pathlen - baselen;
354 i++;
355 }
356 if (is_null_sha1(sha1) ||
358 (mode != S_IFGITLINK && !missing_ok && !has_sha1_file(sha1))) {
359 strbuf_release(&buffer);
360 if (expected_missing)
361 return -1;
362 return error("invalid object %06o %s for '%.*s'",
363 mode, sha1_to_hex(sha1), entlen+baselen, path);
364 }
365 /*
367 * CE_REMOVE entries are removed before the index is
368 * written to disk. Skip them to remain consistent
369 * with the future on-disk index.
370 */
371 if (ce->ce_flags & CE_REMOVE) {
372 *skip_count = *skip_count + 1;
373 continue;
374 }
375 /*
377 * CE_INTENT_TO_ADD entries exist on on-disk index but
378 * they are not part of generated trees. Invalidate up
379 * to root to force cache-tree users to read elsewhere.
380 */
381 if (!sub && ce_intent_to_add(ce)) {
382 to_invalidate = 1;
383 continue;
384 }
385 /*
387 * "sub" can be an empty tree if all subentries are i-t-a.
388 */
389 if (contains_ita && !hashcmp(sha1, EMPTY_TREE_SHA1_BIN))
390 continue;
391 strbuf_grow(&buffer, entlen + 100);
393 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
394 strbuf_add(&buffer, sha1, 20);
395#if DEBUG
397 fprintf(stderr, "cache-tree update-one %o %.*s\n",
398 mode, entlen, path + baselen);
399#endif
400 }
401 if (repair) {
403 unsigned char sha1[20];
404 hash_sha1_file(buffer.buf, buffer.len, tree_type, sha1);
405 if (has_sha1_file(sha1))
406 hashcpy(it->oid.hash, sha1);
407 else
408 to_invalidate = 1;
409 } else if (dryrun)
410 hash_sha1_file(buffer.buf, buffer.len, tree_type,
411 it->oid.hash);
412 else if (write_sha1_file(buffer.buf, buffer.len, tree_type, it->oid.hash)) {
413 strbuf_release(&buffer);
414 return -1;
415 }
416 strbuf_release(&buffer);
418 it->entry_count = to_invalidate ? -1 : i - *skip_count;
419#if DEBUG
420 fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
421 it->entry_count, it->subtree_nr,
422 oid_to_hex(&it->oid));
423#endif
424 return i;
425}
426int cache_tree_update(struct index_state *istate, int flags)
428{
429 struct cache_tree *it = istate->cache_tree;
430 struct cache_entry **cache = istate->cache;
431 int entries = istate->cache_nr;
432 int skip, i = verify_cache(cache, entries, flags);
433 if (i)
435 return i;
436 i = update_one(it, cache, entries, "", 0, &skip, flags);
437 if (i < 0)
438 return i;
439 istate->cache_changed |= CACHE_TREE_CHANGED;
440 return 0;
441}
442static void write_one(struct strbuf *buffer, struct cache_tree *it,
444 const char *path, int pathlen)
445{
446 int i;
447 /* One "cache-tree" entry consists of the following:
449 * path (NUL terminated)
450 * entry_count, subtree_nr ("%d %d\n")
451 * tree-sha1 (missing if invalid)
452 * subtree_nr "cache-tree" entries for subtrees.
453 */
454 strbuf_grow(buffer, pathlen + 100);
455 strbuf_add(buffer, path, pathlen);
456 strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
457#if DEBUG
459 if (0 <= it->entry_count)
460 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
461 pathlen, path, it->entry_count, it->subtree_nr,
462 oid_to_hex(&it->oid));
463 else
464 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
465 pathlen, path, it->subtree_nr);
466#endif
467 if (0 <= it->entry_count) {
469 strbuf_add(buffer, it->oid.hash, 20);
470 }
471 for (i = 0; i < it->subtree_nr; i++) {
472 struct cache_tree_sub *down = it->down[i];
473 if (i) {
474 struct cache_tree_sub *prev = it->down[i-1];
475 if (subtree_name_cmp(down->name, down->namelen,
476 prev->name, prev->namelen) <= 0)
477 die("fatal - unsorted cache subtree");
478 }
479 write_one(buffer, down->cache_tree, down->name, down->namelen);
480 }
481}
482void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
484{
485 write_one(sb, root, "", 0);
486}
487static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
489{
490 const char *buf = *buffer;
491 unsigned long size = *size_p;
492 const char *cp;
493 char *ep;
494 struct cache_tree *it;
495 int i, subtree_nr;
496 it = NULL;
498 /* skip name, but make sure name exists */
499 while (size && *buf) {
500 size--;
501 buf++;
502 }
503 if (!size)
504 goto free_return;
505 buf++; size--;
506 it = cache_tree();
507 cp = buf;
509 it->entry_count = strtol(cp, &ep, 10);
510 if (cp == ep)
511 goto free_return;
512 cp = ep;
513 subtree_nr = strtol(cp, &ep, 10);
514 if (cp == ep)
515 goto free_return;
516 while (size && *buf && *buf != '\n') {
517 size--;
518 buf++;
519 }
520 if (!size)
521 goto free_return;
522 buf++; size--;
523 if (0 <= it->entry_count) {
524 if (size < 20)
525 goto free_return;
526 hashcpy(it->oid.hash, (const unsigned char*)buf);
527 buf += 20;
528 size -= 20;
529 }
530#if DEBUG
532 if (0 <= it->entry_count)
533 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
534 *buffer, it->entry_count, subtree_nr,
535 oid_to_hex(&it->oid));
536 else
537 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
538 *buffer, subtree_nr);
539#endif
540 /*
542 * Just a heuristic -- we do not add directories that often but
543 * we do not want to have to extend it immediately when we do,
544 * hence +2.
545 */
546 it->subtree_alloc = subtree_nr + 2;
547 it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
548 for (i = 0; i < subtree_nr; i++) {
549 /* read each subtree */
550 struct cache_tree *sub;
551 struct cache_tree_sub *subtree;
552 const char *name = buf;
553 sub = read_one(&buf, &size);
555 if (!sub)
556 goto free_return;
557 subtree = cache_tree_sub(it, name);
558 subtree->cache_tree = sub;
559 }
560 if (subtree_nr != it->subtree_nr)
561 die("cache-tree: internal error");
562 *buffer = buf;
563 *size_p = size;
564 return it;
565 free_return:
567 cache_tree_free(&it);
568 return NULL;
569}
570struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
572{
573 if (buffer[0])
574 return NULL; /* not the whole tree */
575 return read_one(&buffer, &size);
576}
577static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
579{
580 if (!it)
581 return NULL;
582 while (*path) {
583 const char *slash;
584 struct cache_tree_sub *sub;
585 slash = strchrnul(path, '/');
587 /*
588 * Between path and slash is the name of the subtree
589 * to look for.
590 */
591 sub = find_subtree(it, path, slash - path, 0);
592 if (!sub)
593 return NULL;
594 it = sub->cache_tree;
595 path = slash;
597 while (*path == '/')
598 path++;
599 }
600 return it;
601}
602int write_index_as_tree(unsigned char *sha1, struct index_state *index_state, const char *index_path, int flags, const char *prefix)
604{
605 int entries, was_valid, newfd;
606 struct lock_file lock_file = LOCK_INIT;
607 int ret = 0;
608 newfd = hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR);
610 entries = read_index_from(index_state, index_path);
612 if (entries < 0) {
613 ret = WRITE_TREE_UNREADABLE_INDEX;
614 goto out;
615 }
616 if (flags & WRITE_TREE_IGNORE_CACHE_TREE)
617 cache_tree_free(&index_state->cache_tree);
618 if (!index_state->cache_tree)
620 index_state->cache_tree = cache_tree();
621 was_valid = cache_tree_fully_valid(index_state->cache_tree);
623 if (!was_valid) {
624 if (cache_tree_update(index_state, flags) < 0) {
625 ret = WRITE_TREE_UNMERGED_INDEX;
626 goto out;
627 }
628 if (0 <= newfd) {
629 if (!write_locked_index(index_state, &lock_file, COMMIT_LOCK))
630 newfd = -1;
631 }
632 /* Not being able to write is fine -- we are only interested
633 * in updating the cache-tree part, and if the next caller
634 * ends up using the old index with unupdated cache-tree part
635 * it misses the work we did here, but that is just a
636 * performance penalty and not a big deal.
637 */
638 }
639 if (prefix) {
641 struct cache_tree *subtree;
642 subtree = cache_tree_find(index_state->cache_tree, prefix);
643 if (!subtree) {
644 ret = WRITE_TREE_PREFIX_ERROR;
645 goto out;
646 }
647 hashcpy(sha1, subtree->oid.hash);
648 }
649 else
650 hashcpy(sha1, index_state->cache_tree->oid.hash);
651out:
653 if (0 <= newfd)
654 rollback_lock_file(&lock_file);
655 return ret;
656}
657int write_cache_as_tree(unsigned char *sha1, int flags, const char *prefix)
659{
660 return write_index_as_tree(sha1, &the_index, get_index_file(), flags, prefix);
661}
662static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
664{
665 struct tree_desc desc;
666 struct name_entry entry;
667 int cnt;
668 oidcpy(&it->oid, &tree->object.oid);
670 init_tree_desc(&desc, tree->buffer, tree->size);
671 cnt = 0;
672 while (tree_entry(&desc, &entry)) {
673 if (!S_ISDIR(entry.mode))
674 cnt++;
675 else {
676 struct cache_tree_sub *sub;
677 struct tree *subtree = lookup_tree(entry.oid);
678 if (!subtree->object.parsed)
679 parse_tree(subtree);
680 sub = cache_tree_sub(it, entry.path);
681 sub->cache_tree = cache_tree();
682 prime_cache_tree_rec(sub->cache_tree, subtree);
683 cnt += sub->cache_tree->entry_count;
684 }
685 }
686 it->entry_count = cnt;
687}
688void prime_cache_tree(struct index_state *istate, struct tree *tree)
690{
691 cache_tree_free(&istate->cache_tree);
692 istate->cache_tree = cache_tree();
693 prime_cache_tree_rec(istate->cache_tree, tree);
694 istate->cache_changed |= CACHE_TREE_CHANGED;
695}
696/*
698 * find the cache_tree that corresponds to the current level without
699 * exploding the full path into textual form. The root of the
700 * cache tree is given as "root", and our current level is "info".
701 * (1) When at root level, info->prev is NULL, so it is "root" itself.
702 * (2) Otherwise, find the cache_tree that corresponds to one level
703 * above us, and find ourselves in there.
704 */
705static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
706 struct traverse_info *info)
707{
708 struct cache_tree *our_parent;
709 if (!info->prev)
711 return root;
712 our_parent = find_cache_tree_from_traversal(root, info->prev);
713 return cache_tree_find(our_parent, info->name.path);
714}
715int cache_tree_matches_traversal(struct cache_tree *root,
717 struct name_entry *ent,
718 struct traverse_info *info)
719{
720 struct cache_tree *it;
721 it = find_cache_tree_from_traversal(root, info);
723 it = cache_tree_find(it, ent->path);
724 if (it && it->entry_count > 0 && !oidcmp(ent->oid, &it->oid))
725 return it->entry_count;
726 return 0;
727}
728int update_main_cache_tree(int flags)
730{
731 if (!the_index.cache_tree)
732 the_index.cache_tree = cache_tree();
733 return cache_tree_update(&the_index, flags);
734}