Merge branch 'rs/janitorial' into maint
[git.git] / cache-tree.c
blob32772b95644d2f32841984b25b685379c6914ad4
1 #include "cache.h"
2 #include "lockfile.h"
3 #include "tree.h"
4 #include "tree-walk.h"
5 #include "cache-tree.h"
7 #ifndef DEBUG
8 #define DEBUG 0
9 #endif
11 struct cache_tree *cache_tree(void)
13 struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
14 it->entry_count = -1;
15 return it;
18 void cache_tree_free(struct cache_tree **it_p)
20 int i;
21 struct cache_tree *it = *it_p;
23 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]);
30 free(it->down);
31 free(it);
32 *it_p = NULL;
35 static int subtree_name_cmp(const char *one, int onelen,
36 const char *two, int twolen)
38 if (onelen < twolen)
39 return -1;
40 if (twolen < onelen)
41 return 1;
42 return memcmp(one, two, onelen);
45 static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
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;
63 return -lo-1;
66 static struct cache_tree_sub *find_subtree(struct cache_tree *it,
67 const char *path,
68 int pathlen,
69 int create)
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;
78 pos = -pos-1;
79 ALLOC_GROW(it->down, it->subtree_nr + 1, it->subtree_alloc);
80 it->subtree_nr++;
82 down = xmalloc(sizeof(*down) + pathlen + 1);
83 down->cache_tree = NULL;
84 down->namelen = pathlen;
85 memcpy(down->name, path, pathlen);
86 down->name[pathlen] = 0;
88 if (pos < it->subtree_nr)
89 memmove(it->down + pos + 1,
90 it->down + pos,
91 sizeof(down) * (it->subtree_nr - pos - 1));
92 it->down[pos] = down;
93 return down;
96 struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
98 int pathlen = strlen(path);
99 return find_subtree(it, path, pathlen, 1);
102 static int do_invalidate_path(struct cache_tree *it, const char *path)
104 /* a/b/c
105 * ==> invalidate self
106 * ==> find "a", have it invalidate "b/c"
108 * ==> invalidate self
109 * ==> if "a" exists as a subtree, remove it.
111 const char *slash;
112 int namelen;
113 struct cache_tree_sub *down;
115 #if DEBUG
116 fprintf(stderr, "cache-tree invalidate <%s>\n", path);
117 #endif
119 if (!it)
120 return 0;
121 slash = strchrnul(path, '/');
122 namelen = slash - path;
123 it->entry_count = -1;
124 if (!*slash) {
125 int pos;
126 pos = subtree_pos(it, path, namelen);
127 if (0 <= pos) {
128 cache_tree_free(&it->down[pos]->cache_tree);
129 free(it->down[pos]);
130 /* 0 1 2 3 4 5
131 * ^ ^subtree_nr = 6
132 * pos
133 * move 4 and 5 up one place (2 entries)
134 * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
136 memmove(it->down+pos, it->down+pos+1,
137 sizeof(struct cache_tree_sub *) *
138 (it->subtree_nr - pos - 1));
139 it->subtree_nr--;
141 return 1;
143 down = find_subtree(it, path, namelen, 0);
144 if (down)
145 do_invalidate_path(down->cache_tree, slash + 1);
146 return 1;
149 void cache_tree_invalidate_path(struct index_state *istate, const char *path)
151 if (do_invalidate_path(istate->cache_tree, path))
152 istate->cache_changed |= CACHE_TREE_CHANGED;
155 static int verify_cache(struct cache_entry **cache,
156 int entries, int flags)
158 int i, funny;
159 int silent = flags & WRITE_TREE_SILENT;
161 /* Verify that the tree is merged */
162 funny = 0;
163 for (i = 0; i < entries; i++) {
164 const struct cache_entry *ce = cache[i];
165 if (ce_stage(ce)) {
166 if (silent)
167 return -1;
168 if (10 < ++funny) {
169 fprintf(stderr, "...\n");
170 break;
172 fprintf(stderr, "%s: unmerged (%s)\n",
173 ce->name, sha1_to_hex(ce->sha1));
176 if (funny)
177 return -1;
179 /* Also verify that the cache does not have path and path/file
180 * at the same time. At this point we know the cache has only
181 * stage 0 entries.
183 funny = 0;
184 for (i = 0; i < entries - 1; i++) {
185 /* path/file always comes after path because of the way
186 * the cache is sorted. Also path can appear only once,
187 * which means conflicting one would immediately follow.
189 const char *this_name = cache[i]->name;
190 const char *next_name = cache[i+1]->name;
191 int this_len = strlen(this_name);
192 if (this_len < strlen(next_name) &&
193 strncmp(this_name, next_name, this_len) == 0 &&
194 next_name[this_len] == '/') {
195 if (10 < ++funny) {
196 fprintf(stderr, "...\n");
197 break;
199 fprintf(stderr, "You have both %s and %s\n",
200 this_name, next_name);
203 if (funny)
204 return -1;
205 return 0;
208 static void discard_unused_subtrees(struct cache_tree *it)
210 struct cache_tree_sub **down = it->down;
211 int nr = it->subtree_nr;
212 int dst, src;
213 for (dst = src = 0; src < nr; src++) {
214 struct cache_tree_sub *s = down[src];
215 if (s->used)
216 down[dst++] = s;
217 else {
218 cache_tree_free(&s->cache_tree);
219 free(s);
220 it->subtree_nr--;
225 int cache_tree_fully_valid(struct cache_tree *it)
227 int i;
228 if (!it)
229 return 0;
230 if (it->entry_count < 0 || !has_sha1_file(it->sha1))
231 return 0;
232 for (i = 0; i < it->subtree_nr; i++) {
233 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
234 return 0;
236 return 1;
239 static int update_one(struct cache_tree *it,
240 struct cache_entry **cache,
241 int entries,
242 const char *base,
243 int baselen,
244 int *skip_count,
245 int flags)
247 struct strbuf buffer;
248 int missing_ok = flags & WRITE_TREE_MISSING_OK;
249 int dryrun = flags & WRITE_TREE_DRY_RUN;
250 int repair = flags & WRITE_TREE_REPAIR;
251 int to_invalidate = 0;
252 int i;
254 assert(!(dryrun && repair));
256 *skip_count = 0;
258 if (0 <= it->entry_count && has_sha1_file(it->sha1))
259 return it->entry_count;
262 * We first scan for subtrees and update them; we start by
263 * marking existing subtrees -- the ones that are unmarked
264 * should not be in the result.
266 for (i = 0; i < it->subtree_nr; i++)
267 it->down[i]->used = 0;
270 * Find the subtrees and update them.
272 i = 0;
273 while (i < entries) {
274 const struct cache_entry *ce = cache[i];
275 struct cache_tree_sub *sub;
276 const char *path, *slash;
277 int pathlen, sublen, subcnt, subskip;
279 path = ce->name;
280 pathlen = ce_namelen(ce);
281 if (pathlen <= baselen || memcmp(base, path, baselen))
282 break; /* at the end of this level */
284 slash = strchr(path + baselen, '/');
285 if (!slash) {
286 i++;
287 continue;
290 * a/bbb/c (base = a/, slash = /c)
291 * ==>
292 * path+baselen = bbb/c, sublen = 3
294 sublen = slash - (path + baselen);
295 sub = find_subtree(it, path + baselen, sublen, 1);
296 if (!sub->cache_tree)
297 sub->cache_tree = cache_tree();
298 subcnt = update_one(sub->cache_tree,
299 cache + i, entries - i,
300 path,
301 baselen + sublen + 1,
302 &subskip,
303 flags);
304 if (subcnt < 0)
305 return subcnt;
306 if (!subcnt)
307 die("index cache-tree records empty sub-tree");
308 i += subcnt;
309 sub->count = subcnt; /* to be used in the next loop */
310 *skip_count += subskip;
311 sub->used = 1;
314 discard_unused_subtrees(it);
317 * Then write out the tree object for this level.
319 strbuf_init(&buffer, 8192);
321 i = 0;
322 while (i < entries) {
323 const struct cache_entry *ce = cache[i];
324 struct cache_tree_sub *sub;
325 const char *path, *slash;
326 int pathlen, entlen;
327 const unsigned char *sha1;
328 unsigned mode;
329 int expected_missing = 0;
331 path = ce->name;
332 pathlen = ce_namelen(ce);
333 if (pathlen <= baselen || memcmp(base, path, baselen))
334 break; /* at the end of this level */
336 slash = strchr(path + baselen, '/');
337 if (slash) {
338 entlen = slash - (path + baselen);
339 sub = find_subtree(it, path + baselen, entlen, 0);
340 if (!sub)
341 die("cache-tree.c: '%.*s' in '%s' not found",
342 entlen, path + baselen, path);
343 i += sub->count;
344 sha1 = sub->cache_tree->sha1;
345 mode = S_IFDIR;
346 if (sub->cache_tree->entry_count < 0) {
347 to_invalidate = 1;
348 expected_missing = 1;
351 else {
352 sha1 = ce->sha1;
353 mode = ce->ce_mode;
354 entlen = pathlen - baselen;
355 i++;
357 if (mode != S_IFGITLINK && !missing_ok && !has_sha1_file(sha1)) {
358 strbuf_release(&buffer);
359 if (expected_missing)
360 return -1;
361 return error("invalid object %06o %s for '%.*s'",
362 mode, sha1_to_hex(sha1), entlen+baselen, path);
366 * CE_REMOVE entries are removed before the index is
367 * written to disk. Skip them to remain consistent
368 * with the future on-disk index.
370 if (ce->ce_flags & CE_REMOVE) {
371 *skip_count = *skip_count + 1;
372 continue;
376 * CE_INTENT_TO_ADD entries exist on on-disk index but
377 * they are not part of generated trees. Invalidate up
378 * to root to force cache-tree users to read elsewhere.
380 if (ce->ce_flags & CE_INTENT_TO_ADD) {
381 to_invalidate = 1;
382 continue;
385 strbuf_grow(&buffer, entlen + 100);
386 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
387 strbuf_add(&buffer, sha1, 20);
389 #if DEBUG
390 fprintf(stderr, "cache-tree update-one %o %.*s\n",
391 mode, entlen, path + baselen);
392 #endif
395 if (repair) {
396 unsigned char sha1[20];
397 hash_sha1_file(buffer.buf, buffer.len, tree_type, sha1);
398 if (has_sha1_file(sha1))
399 hashcpy(it->sha1, sha1);
400 else
401 to_invalidate = 1;
402 } else if (dryrun)
403 hash_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
404 else if (write_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1)) {
405 strbuf_release(&buffer);
406 return -1;
409 strbuf_release(&buffer);
410 it->entry_count = to_invalidate ? -1 : i - *skip_count;
411 #if DEBUG
412 fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
413 it->entry_count, it->subtree_nr,
414 sha1_to_hex(it->sha1));
415 #endif
416 return i;
419 int cache_tree_update(struct index_state *istate, int flags)
421 struct cache_tree *it = istate->cache_tree;
422 struct cache_entry **cache = istate->cache;
423 int entries = istate->cache_nr;
424 int skip, i = verify_cache(cache, entries, flags);
426 if (i)
427 return i;
428 i = update_one(it, cache, entries, "", 0, &skip, flags);
429 if (i < 0)
430 return i;
431 istate->cache_changed |= CACHE_TREE_CHANGED;
432 return 0;
435 static void write_one(struct strbuf *buffer, struct cache_tree *it,
436 const char *path, int pathlen)
438 int i;
440 /* One "cache-tree" entry consists of the following:
441 * path (NUL terminated)
442 * entry_count, subtree_nr ("%d %d\n")
443 * tree-sha1 (missing if invalid)
444 * subtree_nr "cache-tree" entries for subtrees.
446 strbuf_grow(buffer, pathlen + 100);
447 strbuf_add(buffer, path, pathlen);
448 strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
450 #if DEBUG
451 if (0 <= it->entry_count)
452 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
453 pathlen, path, it->entry_count, it->subtree_nr,
454 sha1_to_hex(it->sha1));
455 else
456 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
457 pathlen, path, it->subtree_nr);
458 #endif
460 if (0 <= it->entry_count) {
461 strbuf_add(buffer, it->sha1, 20);
463 for (i = 0; i < it->subtree_nr; i++) {
464 struct cache_tree_sub *down = it->down[i];
465 if (i) {
466 struct cache_tree_sub *prev = it->down[i-1];
467 if (subtree_name_cmp(down->name, down->namelen,
468 prev->name, prev->namelen) <= 0)
469 die("fatal - unsorted cache subtree");
471 write_one(buffer, down->cache_tree, down->name, down->namelen);
475 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
477 write_one(sb, root, "", 0);
480 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
482 const char *buf = *buffer;
483 unsigned long size = *size_p;
484 const char *cp;
485 char *ep;
486 struct cache_tree *it;
487 int i, subtree_nr;
489 it = NULL;
490 /* skip name, but make sure name exists */
491 while (size && *buf) {
492 size--;
493 buf++;
495 if (!size)
496 goto free_return;
497 buf++; size--;
498 it = cache_tree();
500 cp = buf;
501 it->entry_count = strtol(cp, &ep, 10);
502 if (cp == ep)
503 goto free_return;
504 cp = ep;
505 subtree_nr = strtol(cp, &ep, 10);
506 if (cp == ep)
507 goto free_return;
508 while (size && *buf && *buf != '\n') {
509 size--;
510 buf++;
512 if (!size)
513 goto free_return;
514 buf++; size--;
515 if (0 <= it->entry_count) {
516 if (size < 20)
517 goto free_return;
518 hashcpy(it->sha1, (const unsigned char*)buf);
519 buf += 20;
520 size -= 20;
523 #if DEBUG
524 if (0 <= it->entry_count)
525 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
526 *buffer, it->entry_count, subtree_nr,
527 sha1_to_hex(it->sha1));
528 else
529 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
530 *buffer, subtree_nr);
531 #endif
534 * Just a heuristic -- we do not add directories that often but
535 * we do not want to have to extend it immediately when we do,
536 * hence +2.
538 it->subtree_alloc = subtree_nr + 2;
539 it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
540 for (i = 0; i < subtree_nr; i++) {
541 /* read each subtree */
542 struct cache_tree *sub;
543 struct cache_tree_sub *subtree;
544 const char *name = buf;
546 sub = read_one(&buf, &size);
547 if (!sub)
548 goto free_return;
549 subtree = cache_tree_sub(it, name);
550 subtree->cache_tree = sub;
552 if (subtree_nr != it->subtree_nr)
553 die("cache-tree: internal error");
554 *buffer = buf;
555 *size_p = size;
556 return it;
558 free_return:
559 cache_tree_free(&it);
560 return NULL;
563 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
565 if (buffer[0])
566 return NULL; /* not the whole tree */
567 return read_one(&buffer, &size);
570 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
572 if (!it)
573 return NULL;
574 while (*path) {
575 const char *slash;
576 struct cache_tree_sub *sub;
578 slash = strchrnul(path, '/');
580 * Between path and slash is the name of the subtree
581 * to look for.
583 sub = find_subtree(it, path, slash - path, 0);
584 if (!sub)
585 return NULL;
586 it = sub->cache_tree;
588 path = slash;
589 while (*path == '/')
590 path++;
592 return it;
595 int write_cache_as_tree(unsigned char *sha1, int flags, const char *prefix)
597 int entries, was_valid, newfd;
598 struct lock_file *lock_file;
601 * We can't free this memory, it becomes part of a linked list
602 * parsed atexit()
604 lock_file = xcalloc(1, sizeof(struct lock_file));
606 newfd = hold_locked_index(lock_file, 1);
608 entries = read_cache();
609 if (entries < 0)
610 return WRITE_TREE_UNREADABLE_INDEX;
611 if (flags & WRITE_TREE_IGNORE_CACHE_TREE)
612 cache_tree_free(&(active_cache_tree));
614 if (!active_cache_tree)
615 active_cache_tree = cache_tree();
617 was_valid = cache_tree_fully_valid(active_cache_tree);
618 if (!was_valid) {
619 if (cache_tree_update(&the_index, flags) < 0)
620 return WRITE_TREE_UNMERGED_INDEX;
621 if (0 <= newfd) {
622 if (!write_locked_index(&the_index, lock_file, COMMIT_LOCK))
623 newfd = -1;
625 /* Not being able to write is fine -- we are only interested
626 * in updating the cache-tree part, and if the next caller
627 * ends up using the old index with unupdated cache-tree part
628 * it misses the work we did here, but that is just a
629 * performance penalty and not a big deal.
633 if (prefix) {
634 struct cache_tree *subtree =
635 cache_tree_find(active_cache_tree, prefix);
636 if (!subtree)
637 return WRITE_TREE_PREFIX_ERROR;
638 hashcpy(sha1, subtree->sha1);
640 else
641 hashcpy(sha1, active_cache_tree->sha1);
643 if (0 <= newfd)
644 rollback_lock_file(lock_file);
646 return 0;
649 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
651 struct tree_desc desc;
652 struct name_entry entry;
653 int cnt;
655 hashcpy(it->sha1, tree->object.sha1);
656 init_tree_desc(&desc, tree->buffer, tree->size);
657 cnt = 0;
658 while (tree_entry(&desc, &entry)) {
659 if (!S_ISDIR(entry.mode))
660 cnt++;
661 else {
662 struct cache_tree_sub *sub;
663 struct tree *subtree = lookup_tree(entry.sha1);
664 if (!subtree->object.parsed)
665 parse_tree(subtree);
666 sub = cache_tree_sub(it, entry.path);
667 sub->cache_tree = cache_tree();
668 prime_cache_tree_rec(sub->cache_tree, subtree);
669 cnt += sub->cache_tree->entry_count;
672 it->entry_count = cnt;
675 void prime_cache_tree(struct index_state *istate, struct tree *tree)
677 cache_tree_free(&istate->cache_tree);
678 istate->cache_tree = cache_tree();
679 prime_cache_tree_rec(istate->cache_tree, tree);
680 istate->cache_changed |= CACHE_TREE_CHANGED;
684 * find the cache_tree that corresponds to the current level without
685 * exploding the full path into textual form. The root of the
686 * cache tree is given as "root", and our current level is "info".
687 * (1) When at root level, info->prev is NULL, so it is "root" itself.
688 * (2) Otherwise, find the cache_tree that corresponds to one level
689 * above us, and find ourselves in there.
691 static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
692 struct traverse_info *info)
694 struct cache_tree *our_parent;
696 if (!info->prev)
697 return root;
698 our_parent = find_cache_tree_from_traversal(root, info->prev);
699 return cache_tree_find(our_parent, info->name.path);
702 int cache_tree_matches_traversal(struct cache_tree *root,
703 struct name_entry *ent,
704 struct traverse_info *info)
706 struct cache_tree *it;
708 it = find_cache_tree_from_traversal(root, info);
709 it = cache_tree_find(it, ent->path);
710 if (it && it->entry_count > 0 && !hashcmp(ent->sha1, it->sha1))
711 return it->entry_count;
712 return 0;
715 int update_main_cache_tree(int flags)
717 if (!the_index.cache_tree)
718 the_index.cache_tree = cache_tree();
719 return cache_tree_update(&the_index, flags);