user-manual: Fix 'both: so' -> 'both; so' typo
[git/jnareb-git.git] / cache-tree.c
blob37e4d008b59420338ce97f1b2cf2eb660dab8a34
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 if (it->subtree_alloc <= it->subtree_nr) {
79 it->subtree_alloc = alloc_nr(it->subtree_alloc);
80 it->down = xrealloc(it->down, it->subtree_alloc *
81 sizeof(*it->down));
83 it->subtree_nr++;
85 down = xmalloc(sizeof(*down) + pathlen + 1);
86 down->cache_tree = NULL;
87 down->namelen = pathlen;
88 memcpy(down->name, path, pathlen);
89 down->name[pathlen] = 0;
91 if (pos < it->subtree_nr)
92 memmove(it->down + pos + 1,
93 it->down + pos,
94 sizeof(down) * (it->subtree_nr - pos - 1));
95 it->down[pos] = down;
96 return down;
99 struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
101 int pathlen = strlen(path);
102 return find_subtree(it, path, pathlen, 1);
105 void cache_tree_invalidate_path(struct cache_tree *it, const char *path)
107 /* a/b/c
108 * ==> invalidate self
109 * ==> find "a", have it invalidate "b/c"
111 * ==> invalidate self
112 * ==> if "a" exists as a subtree, remove it.
114 const char *slash;
115 int namelen;
116 struct cache_tree_sub *down;
118 #if DEBUG
119 fprintf(stderr, "cache-tree invalidate <%s>\n", path);
120 #endif
122 if (!it)
123 return;
124 slash = strchr(path, '/');
125 it->entry_count = -1;
126 if (!slash) {
127 int pos;
128 namelen = strlen(path);
129 pos = subtree_pos(it, path, namelen);
130 if (0 <= pos) {
131 cache_tree_free(&it->down[pos]->cache_tree);
132 free(it->down[pos]);
133 /* 0 1 2 3 4 5
134 * ^ ^subtree_nr = 6
135 * pos
136 * move 4 and 5 up one place (2 entries)
137 * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
139 memmove(it->down+pos, it->down+pos+1,
140 sizeof(struct cache_tree_sub *) *
141 (it->subtree_nr - pos - 1));
142 it->subtree_nr--;
144 return;
146 namelen = slash - path;
147 down = find_subtree(it, path, namelen, 0);
148 if (down)
149 cache_tree_invalidate_path(down->cache_tree, slash + 1);
152 static int verify_cache(struct cache_entry **cache,
153 int entries, int flags)
155 int i, funny;
156 int silent = flags & WRITE_TREE_SILENT;
158 /* Verify that the tree is merged */
159 funny = 0;
160 for (i = 0; i < entries; i++) {
161 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;
169 fprintf(stderr, "%s: unmerged (%s)\n",
170 ce->name, sha1_to_hex(ce->sha1));
173 if (funny)
174 return -1;
176 /* 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.
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.
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;
196 fprintf(stderr, "You have both %s and %s\n",
197 this_name, next_name);
200 if (funny)
201 return -1;
202 return 0;
205 static void discard_unused_subtrees(struct cache_tree *it)
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--;
222 int cache_tree_fully_valid(struct cache_tree *it)
224 int i;
225 if (!it)
226 return 0;
227 if (it->entry_count < 0 || !has_sha1_file(it->sha1))
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;
233 return 1;
236 static 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)
244 struct strbuf buffer;
245 int missing_ok = flags & WRITE_TREE_MISSING_OK;
246 int dryrun = flags & WRITE_TREE_DRY_RUN;
247 int to_invalidate = 0;
248 int i;
250 *skip_count = 0;
252 if (0 <= it->entry_count && has_sha1_file(it->sha1))
253 return it->entry_count;
256 * We first scan for subtrees and update them; we start by
257 * marking existing subtrees -- the ones that are unmarked
258 * should not be in the result.
260 for (i = 0; i < it->subtree_nr; i++)
261 it->down[i]->used = 0;
264 * Find the subtrees and update them.
266 i = 0;
267 while (i < entries) {
268 struct cache_entry *ce = cache[i];
269 struct cache_tree_sub *sub;
270 const char *path, *slash;
271 int pathlen, sublen, subcnt, subskip;
273 path = ce->name;
274 pathlen = ce_namelen(ce);
275 if (pathlen <= baselen || memcmp(base, path, baselen))
276 break; /* at the end of this level */
278 slash = strchr(path + baselen, '/');
279 if (!slash) {
280 i++;
281 continue;
284 * a/bbb/c (base = a/, slash = /c)
285 * ==>
286 * path+baselen = bbb/c, sublen = 3
288 sublen = slash - (path + baselen);
289 sub = find_subtree(it, path + baselen, sublen, 1);
290 if (!sub->cache_tree)
291 sub->cache_tree = cache_tree();
292 subcnt = update_one(sub->cache_tree,
293 cache + i, entries - i,
294 path,
295 baselen + sublen + 1,
296 &subskip,
297 flags);
298 if (subcnt < 0)
299 return subcnt;
300 i += subcnt;
301 sub->count = subcnt; /* to be used in the next loop */
302 *skip_count += subskip;
303 sub->used = 1;
306 discard_unused_subtrees(it);
309 * Then write out the tree object for this level.
311 strbuf_init(&buffer, 8192);
313 i = 0;
314 while (i < entries) {
315 struct cache_entry *ce = cache[i];
316 struct cache_tree_sub *sub;
317 const char *path, *slash;
318 int pathlen, entlen;
319 const unsigned char *sha1;
320 unsigned mode;
322 path = ce->name;
323 pathlen = ce_namelen(ce);
324 if (pathlen <= baselen || memcmp(base, path, baselen))
325 break; /* at the end of this level */
327 slash = strchr(path + baselen, '/');
328 if (slash) {
329 entlen = slash - (path + baselen);
330 sub = find_subtree(it, path + baselen, entlen, 0);
331 if (!sub)
332 die("cache-tree.c: '%.*s' in '%s' not found",
333 entlen, path + baselen, path);
334 i += sub->count;
335 sha1 = sub->cache_tree->sha1;
336 mode = S_IFDIR;
337 if (sub->cache_tree->entry_count < 0)
338 to_invalidate = 1;
340 else {
341 sha1 = ce->sha1;
342 mode = ce->ce_mode;
343 entlen = pathlen - baselen;
344 i++;
346 if (mode != S_IFGITLINK && !missing_ok && !has_sha1_file(sha1)) {
347 strbuf_release(&buffer);
348 return error("invalid object %06o %s for '%.*s'",
349 mode, sha1_to_hex(sha1), entlen+baselen, path);
353 * CE_REMOVE entries are removed before the index is
354 * written to disk. Skip them to remain consistent
355 * with the future on-disk index.
357 if (ce->ce_flags & CE_REMOVE) {
358 *skip_count = *skip_count + 1;
359 continue;
363 * CE_INTENT_TO_ADD entries exist on on-disk index but
364 * they are not part of generated trees. Invalidate up
365 * to root to force cache-tree users to read elsewhere.
367 if (ce->ce_flags & CE_INTENT_TO_ADD) {
368 to_invalidate = 1;
369 continue;
372 strbuf_grow(&buffer, entlen + 100);
373 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
374 strbuf_add(&buffer, sha1, 20);
376 #if DEBUG
377 fprintf(stderr, "cache-tree update-one %o %.*s\n",
378 mode, entlen, path + baselen);
379 #endif
382 if (dryrun)
383 hash_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
384 else if (write_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1)) {
385 strbuf_release(&buffer);
386 return -1;
389 strbuf_release(&buffer);
390 it->entry_count = to_invalidate ? -1 : i - *skip_count;
391 #if DEBUG
392 fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
393 it->entry_count, it->subtree_nr,
394 sha1_to_hex(it->sha1));
395 #endif
396 return i;
399 int cache_tree_update(struct cache_tree *it,
400 struct cache_entry **cache,
401 int entries,
402 int flags)
404 int i, skip;
405 i = verify_cache(cache, entries, flags);
406 if (i)
407 return i;
408 i = update_one(it, cache, entries, "", 0, &skip, flags);
409 if (i < 0)
410 return i;
411 return 0;
414 static void write_one(struct strbuf *buffer, struct cache_tree *it,
415 const char *path, int pathlen)
417 int i;
419 /* One "cache-tree" entry consists of the following:
420 * path (NUL terminated)
421 * entry_count, subtree_nr ("%d %d\n")
422 * tree-sha1 (missing if invalid)
423 * subtree_nr "cache-tree" entries for subtrees.
425 strbuf_grow(buffer, pathlen + 100);
426 strbuf_add(buffer, path, pathlen);
427 strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
429 #if DEBUG
430 if (0 <= it->entry_count)
431 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
432 pathlen, path, it->entry_count, it->subtree_nr,
433 sha1_to_hex(it->sha1));
434 else
435 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
436 pathlen, path, it->subtree_nr);
437 #endif
439 if (0 <= it->entry_count) {
440 strbuf_add(buffer, it->sha1, 20);
442 for (i = 0; i < it->subtree_nr; i++) {
443 struct cache_tree_sub *down = it->down[i];
444 if (i) {
445 struct cache_tree_sub *prev = it->down[i-1];
446 if (subtree_name_cmp(down->name, down->namelen,
447 prev->name, prev->namelen) <= 0)
448 die("fatal - unsorted cache subtree");
450 write_one(buffer, down->cache_tree, down->name, down->namelen);
454 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
456 write_one(sb, root, "", 0);
459 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
461 const char *buf = *buffer;
462 unsigned long size = *size_p;
463 const char *cp;
464 char *ep;
465 struct cache_tree *it;
466 int i, subtree_nr;
468 it = NULL;
469 /* skip name, but make sure name exists */
470 while (size && *buf) {
471 size--;
472 buf++;
474 if (!size)
475 goto free_return;
476 buf++; size--;
477 it = cache_tree();
479 cp = buf;
480 it->entry_count = strtol(cp, &ep, 10);
481 if (cp == ep)
482 goto free_return;
483 cp = ep;
484 subtree_nr = strtol(cp, &ep, 10);
485 if (cp == ep)
486 goto free_return;
487 while (size && *buf && *buf != '\n') {
488 size--;
489 buf++;
491 if (!size)
492 goto free_return;
493 buf++; size--;
494 if (0 <= it->entry_count) {
495 if (size < 20)
496 goto free_return;
497 hashcpy(it->sha1, (const unsigned char*)buf);
498 buf += 20;
499 size -= 20;
502 #if DEBUG
503 if (0 <= it->entry_count)
504 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
505 *buffer, it->entry_count, subtree_nr,
506 sha1_to_hex(it->sha1));
507 else
508 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
509 *buffer, subtree_nr);
510 #endif
513 * Just a heuristic -- we do not add directories that often but
514 * we do not want to have to extend it immediately when we do,
515 * hence +2.
517 it->subtree_alloc = subtree_nr + 2;
518 it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
519 for (i = 0; i < subtree_nr; i++) {
520 /* read each subtree */
521 struct cache_tree *sub;
522 struct cache_tree_sub *subtree;
523 const char *name = buf;
525 sub = read_one(&buf, &size);
526 if (!sub)
527 goto free_return;
528 subtree = cache_tree_sub(it, name);
529 subtree->cache_tree = sub;
531 if (subtree_nr != it->subtree_nr)
532 die("cache-tree: internal error");
533 *buffer = buf;
534 *size_p = size;
535 return it;
537 free_return:
538 cache_tree_free(&it);
539 return NULL;
542 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
544 if (buffer[0])
545 return NULL; /* not the whole tree */
546 return read_one(&buffer, &size);
549 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
551 if (!it)
552 return NULL;
553 while (*path) {
554 const char *slash;
555 struct cache_tree_sub *sub;
557 slash = strchr(path, '/');
558 if (!slash)
559 slash = path + strlen(path);
560 /* between path and slash is the name of the
561 * subtree to look for.
563 sub = find_subtree(it, path, slash - path, 0);
564 if (!sub)
565 return NULL;
566 it = sub->cache_tree;
567 if (slash)
568 while (*slash && *slash == '/')
569 slash++;
570 if (!slash || !*slash)
571 return it; /* prefix ended with slashes */
572 path = slash;
574 return it;
577 int write_cache_as_tree(unsigned char *sha1, int flags, const char *prefix)
579 int entries, was_valid, newfd;
580 struct lock_file *lock_file;
583 * We can't free this memory, it becomes part of a linked list
584 * parsed atexit()
586 lock_file = xcalloc(1, sizeof(struct lock_file));
588 newfd = hold_locked_index(lock_file, 1);
590 entries = read_cache();
591 if (entries < 0)
592 return WRITE_TREE_UNREADABLE_INDEX;
593 if (flags & WRITE_TREE_IGNORE_CACHE_TREE)
594 cache_tree_free(&(active_cache_tree));
596 if (!active_cache_tree)
597 active_cache_tree = cache_tree();
599 was_valid = cache_tree_fully_valid(active_cache_tree);
600 if (!was_valid) {
601 if (cache_tree_update(active_cache_tree,
602 active_cache, active_nr,
603 flags) < 0)
604 return WRITE_TREE_UNMERGED_INDEX;
605 if (0 <= newfd) {
606 if (!write_cache(newfd, active_cache, active_nr) &&
607 !commit_lock_file(lock_file))
608 newfd = -1;
610 /* Not being able to write is fine -- we are only interested
611 * in updating the cache-tree part, and if the next caller
612 * ends up using the old index with unupdated cache-tree part
613 * it misses the work we did here, but that is just a
614 * performance penalty and not a big deal.
618 if (prefix) {
619 struct cache_tree *subtree =
620 cache_tree_find(active_cache_tree, prefix);
621 if (!subtree)
622 return WRITE_TREE_PREFIX_ERROR;
623 hashcpy(sha1, subtree->sha1);
625 else
626 hashcpy(sha1, active_cache_tree->sha1);
628 if (0 <= newfd)
629 rollback_lock_file(lock_file);
631 return 0;
634 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
636 struct tree_desc desc;
637 struct name_entry entry;
638 int cnt;
640 hashcpy(it->sha1, tree->object.sha1);
641 init_tree_desc(&desc, tree->buffer, tree->size);
642 cnt = 0;
643 while (tree_entry(&desc, &entry)) {
644 if (!S_ISDIR(entry.mode))
645 cnt++;
646 else {
647 struct cache_tree_sub *sub;
648 struct tree *subtree = lookup_tree(entry.sha1);
649 if (!subtree->object.parsed)
650 parse_tree(subtree);
651 sub = cache_tree_sub(it, entry.path);
652 sub->cache_tree = cache_tree();
653 prime_cache_tree_rec(sub->cache_tree, subtree);
654 cnt += sub->cache_tree->entry_count;
657 it->entry_count = cnt;
660 void prime_cache_tree(struct cache_tree **it, struct tree *tree)
662 cache_tree_free(it);
663 *it = cache_tree();
664 prime_cache_tree_rec(*it, tree);
668 * find the cache_tree that corresponds to the current level without
669 * exploding the full path into textual form. The root of the
670 * cache tree is given as "root", and our current level is "info".
671 * (1) When at root level, info->prev is NULL, so it is "root" itself.
672 * (2) Otherwise, find the cache_tree that corresponds to one level
673 * above us, and find ourselves in there.
675 static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
676 struct traverse_info *info)
678 struct cache_tree *our_parent;
680 if (!info->prev)
681 return root;
682 our_parent = find_cache_tree_from_traversal(root, info->prev);
683 return cache_tree_find(our_parent, info->name.path);
686 int cache_tree_matches_traversal(struct cache_tree *root,
687 struct name_entry *ent,
688 struct traverse_info *info)
690 struct cache_tree *it;
692 it = find_cache_tree_from_traversal(root, info);
693 it = cache_tree_find(it, ent->path);
694 if (it && it->entry_count > 0 && !hashcmp(ent->sha1, it->sha1))
695 return it->entry_count;
696 return 0;
699 int update_main_cache_tree(int flags)
701 if (!the_index.cache_tree)
702 the_index.cache_tree = cache_tree();
703 return cache_tree_update(the_index.cache_tree,
704 the_index.cache, the_index.cache_nr, flags);