Merge branch 'esr/maint-doc-fast-import'
[git.git] / cache-tree.c
blob28ed6574a2faf3151056aa20e681e06a157e4a2d
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 if (ce_stage(ce))
170 fprintf(stderr, "%s: unmerged (%s)\n",
171 ce->name, sha1_to_hex(ce->sha1));
172 else
173 fprintf(stderr, "%s: not added yet\n",
174 ce->name);
177 if (funny)
178 return -1;
180 /* Also verify that the cache does not have path and path/file
181 * at the same time. At this point we know the cache has only
182 * stage 0 entries.
184 funny = 0;
185 for (i = 0; i < entries - 1; i++) {
186 /* path/file always comes after path because of the way
187 * the cache is sorted. Also path can appear only once,
188 * which means conflicting one would immediately follow.
190 const char *this_name = cache[i]->name;
191 const char *next_name = cache[i+1]->name;
192 int this_len = strlen(this_name);
193 if (this_len < strlen(next_name) &&
194 strncmp(this_name, next_name, this_len) == 0 &&
195 next_name[this_len] == '/') {
196 if (10 < ++funny) {
197 fprintf(stderr, "...\n");
198 break;
200 fprintf(stderr, "You have both %s and %s\n",
201 this_name, next_name);
204 if (funny)
205 return -1;
206 return 0;
209 static void discard_unused_subtrees(struct cache_tree *it)
211 struct cache_tree_sub **down = it->down;
212 int nr = it->subtree_nr;
213 int dst, src;
214 for (dst = src = 0; src < nr; src++) {
215 struct cache_tree_sub *s = down[src];
216 if (s->used)
217 down[dst++] = s;
218 else {
219 cache_tree_free(&s->cache_tree);
220 free(s);
221 it->subtree_nr--;
226 int cache_tree_fully_valid(struct cache_tree *it)
228 int i;
229 if (!it)
230 return 0;
231 if (it->entry_count < 0 || !has_sha1_file(it->sha1))
232 return 0;
233 for (i = 0; i < it->subtree_nr; i++) {
234 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
235 return 0;
237 return 1;
240 static int update_one(struct cache_tree *it,
241 struct cache_entry **cache,
242 int entries,
243 const char *base,
244 int baselen,
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 i;
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 for (i = 0; i < entries; i++) {
267 struct cache_entry *ce = cache[i];
268 struct cache_tree_sub *sub;
269 const char *path, *slash;
270 int pathlen, sublen, subcnt;
272 path = ce->name;
273 pathlen = ce_namelen(ce);
274 if (pathlen <= baselen || memcmp(base, path, baselen))
275 break; /* at the end of this level */
277 slash = strchr(path + baselen, '/');
278 if (!slash)
279 continue;
281 * a/bbb/c (base = a/, slash = /c)
282 * ==>
283 * path+baselen = bbb/c, sublen = 3
285 sublen = slash - (path + baselen);
286 sub = find_subtree(it, path + baselen, sublen, 1);
287 if (!sub->cache_tree)
288 sub->cache_tree = cache_tree();
289 subcnt = update_one(sub->cache_tree,
290 cache + i, entries - i,
291 path,
292 baselen + sublen + 1,
293 flags);
294 if (subcnt < 0)
295 return subcnt;
296 i += subcnt - 1;
297 sub->used = 1;
300 discard_unused_subtrees(it);
303 * Then write out the tree object for this level.
305 strbuf_init(&buffer, 8192);
307 for (i = 0; i < entries; i++) {
308 struct cache_entry *ce = cache[i];
309 struct cache_tree_sub *sub;
310 const char *path, *slash;
311 int pathlen, entlen;
312 const unsigned char *sha1;
313 unsigned mode;
315 path = ce->name;
316 pathlen = ce_namelen(ce);
317 if (pathlen <= baselen || memcmp(base, path, baselen))
318 break; /* at the end of this level */
320 slash = strchr(path + baselen, '/');
321 if (slash) {
322 entlen = slash - (path + baselen);
323 sub = find_subtree(it, path + baselen, entlen, 0);
324 if (!sub)
325 die("cache-tree.c: '%.*s' in '%s' not found",
326 entlen, path + baselen, path);
327 i += sub->cache_tree->entry_count - 1;
328 sha1 = sub->cache_tree->sha1;
329 mode = S_IFDIR;
331 else {
332 sha1 = ce->sha1;
333 mode = ce->ce_mode;
334 entlen = pathlen - baselen;
336 if (mode != S_IFGITLINK && !missing_ok && !has_sha1_file(sha1)) {
337 strbuf_release(&buffer);
338 return error("invalid object %06o %s for '%.*s'",
339 mode, sha1_to_hex(sha1), entlen+baselen, path);
342 if (ce->ce_flags & (CE_REMOVE | CE_INTENT_TO_ADD))
343 continue; /* entry being removed or placeholder */
345 strbuf_grow(&buffer, entlen + 100);
346 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
347 strbuf_add(&buffer, sha1, 20);
349 #if DEBUG
350 fprintf(stderr, "cache-tree update-one %o %.*s\n",
351 mode, entlen, path + baselen);
352 #endif
355 if (dryrun)
356 hash_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
357 else if (write_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1)) {
358 strbuf_release(&buffer);
359 return -1;
362 strbuf_release(&buffer);
363 it->entry_count = i;
364 #if DEBUG
365 fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
366 it->entry_count, it->subtree_nr,
367 sha1_to_hex(it->sha1));
368 #endif
369 return i;
372 int cache_tree_update(struct cache_tree *it,
373 struct cache_entry **cache,
374 int entries,
375 int flags)
377 int i;
378 i = verify_cache(cache, entries, flags);
379 if (i)
380 return i;
381 i = update_one(it, cache, entries, "", 0, flags);
382 if (i < 0)
383 return i;
384 return 0;
387 static void write_one(struct strbuf *buffer, struct cache_tree *it,
388 const char *path, int pathlen)
390 int i;
392 /* One "cache-tree" entry consists of the following:
393 * path (NUL terminated)
394 * entry_count, subtree_nr ("%d %d\n")
395 * tree-sha1 (missing if invalid)
396 * subtree_nr "cache-tree" entries for subtrees.
398 strbuf_grow(buffer, pathlen + 100);
399 strbuf_add(buffer, path, pathlen);
400 strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
402 #if DEBUG
403 if (0 <= it->entry_count)
404 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
405 pathlen, path, it->entry_count, it->subtree_nr,
406 sha1_to_hex(it->sha1));
407 else
408 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
409 pathlen, path, it->subtree_nr);
410 #endif
412 if (0 <= it->entry_count) {
413 strbuf_add(buffer, it->sha1, 20);
415 for (i = 0; i < it->subtree_nr; i++) {
416 struct cache_tree_sub *down = it->down[i];
417 if (i) {
418 struct cache_tree_sub *prev = it->down[i-1];
419 if (subtree_name_cmp(down->name, down->namelen,
420 prev->name, prev->namelen) <= 0)
421 die("fatal - unsorted cache subtree");
423 write_one(buffer, down->cache_tree, down->name, down->namelen);
427 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
429 write_one(sb, root, "", 0);
432 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
434 const char *buf = *buffer;
435 unsigned long size = *size_p;
436 const char *cp;
437 char *ep;
438 struct cache_tree *it;
439 int i, subtree_nr;
441 it = NULL;
442 /* skip name, but make sure name exists */
443 while (size && *buf) {
444 size--;
445 buf++;
447 if (!size)
448 goto free_return;
449 buf++; size--;
450 it = cache_tree();
452 cp = buf;
453 it->entry_count = strtol(cp, &ep, 10);
454 if (cp == ep)
455 goto free_return;
456 cp = ep;
457 subtree_nr = strtol(cp, &ep, 10);
458 if (cp == ep)
459 goto free_return;
460 while (size && *buf && *buf != '\n') {
461 size--;
462 buf++;
464 if (!size)
465 goto free_return;
466 buf++; size--;
467 if (0 <= it->entry_count) {
468 if (size < 20)
469 goto free_return;
470 hashcpy(it->sha1, (const unsigned char*)buf);
471 buf += 20;
472 size -= 20;
475 #if DEBUG
476 if (0 <= it->entry_count)
477 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
478 *buffer, it->entry_count, subtree_nr,
479 sha1_to_hex(it->sha1));
480 else
481 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
482 *buffer, subtree_nr);
483 #endif
486 * Just a heuristic -- we do not add directories that often but
487 * we do not want to have to extend it immediately when we do,
488 * hence +2.
490 it->subtree_alloc = subtree_nr + 2;
491 it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
492 for (i = 0; i < subtree_nr; i++) {
493 /* read each subtree */
494 struct cache_tree *sub;
495 struct cache_tree_sub *subtree;
496 const char *name = buf;
498 sub = read_one(&buf, &size);
499 if (!sub)
500 goto free_return;
501 subtree = cache_tree_sub(it, name);
502 subtree->cache_tree = sub;
504 if (subtree_nr != it->subtree_nr)
505 die("cache-tree: internal error");
506 *buffer = buf;
507 *size_p = size;
508 return it;
510 free_return:
511 cache_tree_free(&it);
512 return NULL;
515 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
517 if (buffer[0])
518 return NULL; /* not the whole tree */
519 return read_one(&buffer, &size);
522 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
524 if (!it)
525 return NULL;
526 while (*path) {
527 const char *slash;
528 struct cache_tree_sub *sub;
530 slash = strchr(path, '/');
531 if (!slash)
532 slash = path + strlen(path);
533 /* between path and slash is the name of the
534 * subtree to look for.
536 sub = find_subtree(it, path, slash - path, 0);
537 if (!sub)
538 return NULL;
539 it = sub->cache_tree;
540 if (slash)
541 while (*slash && *slash == '/')
542 slash++;
543 if (!slash || !*slash)
544 return it; /* prefix ended with slashes */
545 path = slash;
547 return it;
550 int write_cache_as_tree(unsigned char *sha1, int flags, const char *prefix)
552 int entries, was_valid, newfd;
553 struct lock_file *lock_file;
556 * We can't free this memory, it becomes part of a linked list
557 * parsed atexit()
559 lock_file = xcalloc(1, sizeof(struct lock_file));
561 newfd = hold_locked_index(lock_file, 1);
563 entries = read_cache();
564 if (entries < 0)
565 return WRITE_TREE_UNREADABLE_INDEX;
566 if (flags & WRITE_TREE_IGNORE_CACHE_TREE)
567 cache_tree_free(&(active_cache_tree));
569 if (!active_cache_tree)
570 active_cache_tree = cache_tree();
572 was_valid = cache_tree_fully_valid(active_cache_tree);
573 if (!was_valid) {
574 if (cache_tree_update(active_cache_tree,
575 active_cache, active_nr,
576 flags) < 0)
577 return WRITE_TREE_UNMERGED_INDEX;
578 if (0 <= newfd) {
579 if (!write_cache(newfd, active_cache, active_nr) &&
580 !commit_lock_file(lock_file))
581 newfd = -1;
583 /* Not being able to write is fine -- we are only interested
584 * in updating the cache-tree part, and if the next caller
585 * ends up using the old index with unupdated cache-tree part
586 * it misses the work we did here, but that is just a
587 * performance penalty and not a big deal.
591 if (prefix) {
592 struct cache_tree *subtree =
593 cache_tree_find(active_cache_tree, prefix);
594 if (!subtree)
595 return WRITE_TREE_PREFIX_ERROR;
596 hashcpy(sha1, subtree->sha1);
598 else
599 hashcpy(sha1, active_cache_tree->sha1);
601 if (0 <= newfd)
602 rollback_lock_file(lock_file);
604 return 0;
607 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
609 struct tree_desc desc;
610 struct name_entry entry;
611 int cnt;
613 hashcpy(it->sha1, tree->object.sha1);
614 init_tree_desc(&desc, tree->buffer, tree->size);
615 cnt = 0;
616 while (tree_entry(&desc, &entry)) {
617 if (!S_ISDIR(entry.mode))
618 cnt++;
619 else {
620 struct cache_tree_sub *sub;
621 struct tree *subtree = lookup_tree(entry.sha1);
622 if (!subtree->object.parsed)
623 parse_tree(subtree);
624 sub = cache_tree_sub(it, entry.path);
625 sub->cache_tree = cache_tree();
626 prime_cache_tree_rec(sub->cache_tree, subtree);
627 cnt += sub->cache_tree->entry_count;
630 it->entry_count = cnt;
633 void prime_cache_tree(struct cache_tree **it, struct tree *tree)
635 cache_tree_free(it);
636 *it = cache_tree();
637 prime_cache_tree_rec(*it, tree);
641 * find the cache_tree that corresponds to the current level without
642 * exploding the full path into textual form. The root of the
643 * cache tree is given as "root", and our current level is "info".
644 * (1) When at root level, info->prev is NULL, so it is "root" itself.
645 * (2) Otherwise, find the cache_tree that corresponds to one level
646 * above us, and find ourselves in there.
648 static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
649 struct traverse_info *info)
651 struct cache_tree *our_parent;
653 if (!info->prev)
654 return root;
655 our_parent = find_cache_tree_from_traversal(root, info->prev);
656 return cache_tree_find(our_parent, info->name.path);
659 int cache_tree_matches_traversal(struct cache_tree *root,
660 struct name_entry *ent,
661 struct traverse_info *info)
663 struct cache_tree *it;
665 it = find_cache_tree_from_traversal(root, info);
666 it = cache_tree_find(it, ent->path);
667 if (it && it->entry_count > 0 && !hashcmp(ent->sha1, it->sha1))
668 return it->entry_count;
669 return 0;
672 int update_main_cache_tree(int flags)
674 if (!the_index.cache_tree)
675 the_index.cache_tree = cache_tree();
676 return cache_tree_update(the_index.cache_tree,
677 the_index.cache, the_index.cache_nr, flags);