Merge branch 'cb/maint-orphan-merge-noclobber'
[git/kirr.git] / cache-tree.c
blobf755590da827234830d8b4359720cfbfd87a3dea
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)
155 int i, funny;
157 /* Verify that the tree is merged */
158 funny = 0;
159 for (i = 0; i < entries; i++) {
160 struct cache_entry *ce = cache[i];
161 if (ce_stage(ce) || (ce->ce_flags & CE_INTENT_TO_ADD)) {
162 if (10 < ++funny) {
163 fprintf(stderr, "...\n");
164 break;
166 if (ce_stage(ce))
167 fprintf(stderr, "%s: unmerged (%s)\n",
168 ce->name, sha1_to_hex(ce->sha1));
169 else
170 fprintf(stderr, "%s: not added yet\n",
171 ce->name);
174 if (funny)
175 return -1;
177 /* Also verify that the cache does not have path and path/file
178 * at the same time. At this point we know the cache has only
179 * stage 0 entries.
181 funny = 0;
182 for (i = 0; i < entries - 1; i++) {
183 /* path/file always comes after path because of the way
184 * the cache is sorted. Also path can appear only once,
185 * which means conflicting one would immediately follow.
187 const char *this_name = cache[i]->name;
188 const char *next_name = cache[i+1]->name;
189 int this_len = strlen(this_name);
190 if (this_len < strlen(next_name) &&
191 strncmp(this_name, next_name, this_len) == 0 &&
192 next_name[this_len] == '/') {
193 if (10 < ++funny) {
194 fprintf(stderr, "...\n");
195 break;
197 fprintf(stderr, "You have both %s and %s\n",
198 this_name, next_name);
201 if (funny)
202 return -1;
203 return 0;
206 static void discard_unused_subtrees(struct cache_tree *it)
208 struct cache_tree_sub **down = it->down;
209 int nr = it->subtree_nr;
210 int dst, src;
211 for (dst = src = 0; src < nr; src++) {
212 struct cache_tree_sub *s = down[src];
213 if (s->used)
214 down[dst++] = s;
215 else {
216 cache_tree_free(&s->cache_tree);
217 free(s);
218 it->subtree_nr--;
223 int cache_tree_fully_valid(struct cache_tree *it)
225 int i;
226 if (!it)
227 return 0;
228 if (it->entry_count < 0 || !has_sha1_file(it->sha1))
229 return 0;
230 for (i = 0; i < it->subtree_nr; i++) {
231 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
232 return 0;
234 return 1;
237 static int update_one(struct cache_tree *it,
238 struct cache_entry **cache,
239 int entries,
240 const char *base,
241 int baselen,
242 int missing_ok,
243 int dryrun)
245 struct strbuf buffer;
246 int i;
248 if (0 <= it->entry_count && has_sha1_file(it->sha1))
249 return it->entry_count;
252 * We first scan for subtrees and update them; we start by
253 * marking existing subtrees -- the ones that are unmarked
254 * should not be in the result.
256 for (i = 0; i < it->subtree_nr; i++)
257 it->down[i]->used = 0;
260 * Find the subtrees and update them.
262 for (i = 0; i < entries; i++) {
263 struct cache_entry *ce = cache[i];
264 struct cache_tree_sub *sub;
265 const char *path, *slash;
266 int pathlen, sublen, subcnt;
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 continue;
277 * a/bbb/c (base = a/, slash = /c)
278 * ==>
279 * path+baselen = bbb/c, sublen = 3
281 sublen = slash - (path + baselen);
282 sub = find_subtree(it, path + baselen, sublen, 1);
283 if (!sub->cache_tree)
284 sub->cache_tree = cache_tree();
285 subcnt = update_one(sub->cache_tree,
286 cache + i, entries - i,
287 path,
288 baselen + sublen + 1,
289 missing_ok,
290 dryrun);
291 if (subcnt < 0)
292 return subcnt;
293 i += subcnt - 1;
294 sub->used = 1;
297 discard_unused_subtrees(it);
300 * Then write out the tree object for this level.
302 strbuf_init(&buffer, 8192);
304 for (i = 0; i < entries; i++) {
305 struct cache_entry *ce = cache[i];
306 struct cache_tree_sub *sub;
307 const char *path, *slash;
308 int pathlen, entlen;
309 const unsigned char *sha1;
310 unsigned mode;
312 path = ce->name;
313 pathlen = ce_namelen(ce);
314 if (pathlen <= baselen || memcmp(base, path, baselen))
315 break; /* at the end of this level */
317 slash = strchr(path + baselen, '/');
318 if (slash) {
319 entlen = slash - (path + baselen);
320 sub = find_subtree(it, path + baselen, entlen, 0);
321 if (!sub)
322 die("cache-tree.c: '%.*s' in '%s' not found",
323 entlen, path + baselen, path);
324 i += sub->cache_tree->entry_count - 1;
325 sha1 = sub->cache_tree->sha1;
326 mode = S_IFDIR;
328 else {
329 sha1 = ce->sha1;
330 mode = ce->ce_mode;
331 entlen = pathlen - baselen;
333 if (mode != S_IFGITLINK && !missing_ok && !has_sha1_file(sha1)) {
334 strbuf_release(&buffer);
335 return error("invalid object %06o %s for '%.*s'",
336 mode, sha1_to_hex(sha1), entlen+baselen, path);
339 if (ce->ce_flags & CE_REMOVE)
340 continue; /* entry being removed */
342 strbuf_grow(&buffer, entlen + 100);
343 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
344 strbuf_add(&buffer, sha1, 20);
346 #if DEBUG
347 fprintf(stderr, "cache-tree update-one %o %.*s\n",
348 mode, entlen, path + baselen);
349 #endif
352 if (dryrun)
353 hash_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
354 else if (write_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1)) {
355 strbuf_release(&buffer);
356 return -1;
359 strbuf_release(&buffer);
360 it->entry_count = i;
361 #if DEBUG
362 fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
363 it->entry_count, it->subtree_nr,
364 sha1_to_hex(it->sha1));
365 #endif
366 return i;
369 int cache_tree_update(struct cache_tree *it,
370 struct cache_entry **cache,
371 int entries,
372 int missing_ok,
373 int dryrun)
375 int i;
376 i = verify_cache(cache, entries);
377 if (i)
378 return i;
379 i = update_one(it, cache, entries, "", 0, missing_ok, dryrun);
380 if (i < 0)
381 return i;
382 return 0;
385 static void write_one(struct strbuf *buffer, struct cache_tree *it,
386 const char *path, int pathlen)
388 int i;
390 /* One "cache-tree" entry consists of the following:
391 * path (NUL terminated)
392 * entry_count, subtree_nr ("%d %d\n")
393 * tree-sha1 (missing if invalid)
394 * subtree_nr "cache-tree" entries for subtrees.
396 strbuf_grow(buffer, pathlen + 100);
397 strbuf_add(buffer, path, pathlen);
398 strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
400 #if DEBUG
401 if (0 <= it->entry_count)
402 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
403 pathlen, path, it->entry_count, it->subtree_nr,
404 sha1_to_hex(it->sha1));
405 else
406 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
407 pathlen, path, it->subtree_nr);
408 #endif
410 if (0 <= it->entry_count) {
411 strbuf_add(buffer, it->sha1, 20);
413 for (i = 0; i < it->subtree_nr; i++) {
414 struct cache_tree_sub *down = it->down[i];
415 if (i) {
416 struct cache_tree_sub *prev = it->down[i-1];
417 if (subtree_name_cmp(down->name, down->namelen,
418 prev->name, prev->namelen) <= 0)
419 die("fatal - unsorted cache subtree");
421 write_one(buffer, down->cache_tree, down->name, down->namelen);
425 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
427 write_one(sb, root, "", 0);
430 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
432 const char *buf = *buffer;
433 unsigned long size = *size_p;
434 const char *cp;
435 char *ep;
436 struct cache_tree *it;
437 int i, subtree_nr;
439 it = NULL;
440 /* skip name, but make sure name exists */
441 while (size && *buf) {
442 size--;
443 buf++;
445 if (!size)
446 goto free_return;
447 buf++; size--;
448 it = cache_tree();
450 cp = buf;
451 it->entry_count = strtol(cp, &ep, 10);
452 if (cp == ep)
453 goto free_return;
454 cp = ep;
455 subtree_nr = strtol(cp, &ep, 10);
456 if (cp == ep)
457 goto free_return;
458 while (size && *buf && *buf != '\n') {
459 size--;
460 buf++;
462 if (!size)
463 goto free_return;
464 buf++; size--;
465 if (0 <= it->entry_count) {
466 if (size < 20)
467 goto free_return;
468 hashcpy(it->sha1, (const unsigned char*)buf);
469 buf += 20;
470 size -= 20;
473 #if DEBUG
474 if (0 <= it->entry_count)
475 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
476 *buffer, it->entry_count, subtree_nr,
477 sha1_to_hex(it->sha1));
478 else
479 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
480 *buffer, subtree_nr);
481 #endif
484 * Just a heuristic -- we do not add directories that often but
485 * we do not want to have to extend it immediately when we do,
486 * hence +2.
488 it->subtree_alloc = subtree_nr + 2;
489 it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
490 for (i = 0; i < subtree_nr; i++) {
491 /* read each subtree */
492 struct cache_tree *sub;
493 struct cache_tree_sub *subtree;
494 const char *name = buf;
496 sub = read_one(&buf, &size);
497 if (!sub)
498 goto free_return;
499 subtree = cache_tree_sub(it, name);
500 subtree->cache_tree = sub;
502 if (subtree_nr != it->subtree_nr)
503 die("cache-tree: internal error");
504 *buffer = buf;
505 *size_p = size;
506 return it;
508 free_return:
509 cache_tree_free(&it);
510 return NULL;
513 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
515 if (buffer[0])
516 return NULL; /* not the whole tree */
517 return read_one(&buffer, &size);
520 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
522 if (!it)
523 return NULL;
524 while (*path) {
525 const char *slash;
526 struct cache_tree_sub *sub;
528 slash = strchr(path, '/');
529 if (!slash)
530 slash = path + strlen(path);
531 /* between path and slash is the name of the
532 * subtree to look for.
534 sub = find_subtree(it, path, slash - path, 0);
535 if (!sub)
536 return NULL;
537 it = sub->cache_tree;
538 if (slash)
539 while (*slash && *slash == '/')
540 slash++;
541 if (!slash || !*slash)
542 return it; /* prefix ended with slashes */
543 path = slash;
545 return it;
548 int write_cache_as_tree(unsigned char *sha1, int flags, const char *prefix)
550 int entries, was_valid, newfd;
551 struct lock_file *lock_file;
554 * We can't free this memory, it becomes part of a linked list
555 * parsed atexit()
557 lock_file = xcalloc(1, sizeof(struct lock_file));
559 newfd = hold_locked_index(lock_file, 1);
561 entries = read_cache();
562 if (entries < 0)
563 return WRITE_TREE_UNREADABLE_INDEX;
564 if (flags & WRITE_TREE_IGNORE_CACHE_TREE)
565 cache_tree_free(&(active_cache_tree));
567 if (!active_cache_tree)
568 active_cache_tree = cache_tree();
570 was_valid = cache_tree_fully_valid(active_cache_tree);
571 if (!was_valid) {
572 int missing_ok = flags & WRITE_TREE_MISSING_OK;
574 if (cache_tree_update(active_cache_tree,
575 active_cache, active_nr,
576 missing_ok, 0) < 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;