gitweb: Add git_merge sub
[git/gsoc2010-gitweb.git] / cache-tree.c
blobd91743775dfbe98d99d8ab25a270af320c8b984e
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);
28 free(it);
29 *it_p = NULL;
32 static int subtree_name_cmp(const char *one, int onelen,
33 const char *two, int twolen)
35 if (onelen < twolen)
36 return -1;
37 if (twolen < onelen)
38 return 1;
39 return memcmp(one, two, onelen);
42 static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
44 struct cache_tree_sub **down = it->down;
45 int lo, hi;
46 lo = 0;
47 hi = it->subtree_nr;
48 while (lo < hi) {
49 int mi = (lo + hi) / 2;
50 struct cache_tree_sub *mdl = down[mi];
51 int cmp = subtree_name_cmp(path, pathlen,
52 mdl->name, mdl->namelen);
53 if (!cmp)
54 return mi;
55 if (cmp < 0)
56 hi = mi;
57 else
58 lo = mi + 1;
60 return -lo-1;
63 static struct cache_tree_sub *find_subtree(struct cache_tree *it,
64 const char *path,
65 int pathlen,
66 int create)
68 struct cache_tree_sub *down;
69 int pos = subtree_pos(it, path, pathlen);
70 if (0 <= pos)
71 return it->down[pos];
72 if (!create)
73 return NULL;
75 pos = -pos-1;
76 if (it->subtree_alloc <= it->subtree_nr) {
77 it->subtree_alloc = alloc_nr(it->subtree_alloc);
78 it->down = xrealloc(it->down, it->subtree_alloc *
79 sizeof(*it->down));
81 it->subtree_nr++;
83 down = xmalloc(sizeof(*down) + pathlen + 1);
84 down->cache_tree = NULL;
85 down->namelen = pathlen;
86 memcpy(down->name, path, pathlen);
87 down->name[pathlen] = 0;
89 if (pos < it->subtree_nr)
90 memmove(it->down + pos + 1,
91 it->down + pos,
92 sizeof(down) * (it->subtree_nr - pos - 1));
93 it->down[pos] = down;
94 return down;
97 struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
99 int pathlen = strlen(path);
100 return find_subtree(it, path, pathlen, 1);
103 void cache_tree_invalidate_path(struct cache_tree *it, const char *path)
105 /* a/b/c
106 * ==> invalidate self
107 * ==> find "a", have it invalidate "b/c"
109 * ==> invalidate self
110 * ==> if "a" exists as a subtree, remove it.
112 const char *slash;
113 int namelen;
114 struct cache_tree_sub *down;
116 #if DEBUG
117 fprintf(stderr, "cache-tree invalidate <%s>\n", path);
118 #endif
120 if (!it)
121 return;
122 slash = strchr(path, '/');
123 it->entry_count = -1;
124 if (!slash) {
125 int pos;
126 namelen = strlen(path);
127 pos = subtree_pos(it, path, namelen);
128 if (0 <= pos) {
129 cache_tree_free(&it->down[pos]->cache_tree);
130 free(it->down[pos]);
131 /* 0 1 2 3 4 5
132 * ^ ^subtree_nr = 6
133 * pos
134 * move 4 and 5 up one place (2 entries)
135 * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
137 memmove(it->down+pos, it->down+pos+1,
138 sizeof(struct cache_tree_sub *) *
139 (it->subtree_nr - pos - 1));
140 it->subtree_nr--;
142 return;
144 namelen = slash - path;
145 down = find_subtree(it, path, namelen, 0);
146 if (down)
147 cache_tree_invalidate_path(down->cache_tree, slash + 1);
150 static int verify_cache(struct cache_entry **cache,
151 int entries)
153 int i, funny;
155 /* Verify that the tree is merged */
156 funny = 0;
157 for (i = 0; i < entries; i++) {
158 struct cache_entry *ce = cache[i];
159 if (ce_stage(ce) || (ce->ce_flags & CE_INTENT_TO_ADD)) {
160 if (10 < ++funny) {
161 fprintf(stderr, "...\n");
162 break;
164 if (ce_stage(ce))
165 fprintf(stderr, "%s: unmerged (%s)\n",
166 ce->name, sha1_to_hex(ce->sha1));
167 else
168 fprintf(stderr, "%s: not added yet\n",
169 ce->name);
172 if (funny)
173 return -1;
175 /* Also verify that the cache does not have path and path/file
176 * at the same time. At this point we know the cache has only
177 * stage 0 entries.
179 funny = 0;
180 for (i = 0; i < entries - 1; i++) {
181 /* path/file always comes after path because of the way
182 * the cache is sorted. Also path can appear only once,
183 * which means conflicting one would immediately follow.
185 const char *this_name = cache[i]->name;
186 const char *next_name = cache[i+1]->name;
187 int this_len = strlen(this_name);
188 if (this_len < strlen(next_name) &&
189 strncmp(this_name, next_name, this_len) == 0 &&
190 next_name[this_len] == '/') {
191 if (10 < ++funny) {
192 fprintf(stderr, "...\n");
193 break;
195 fprintf(stderr, "You have both %s and %s\n",
196 this_name, next_name);
199 if (funny)
200 return -1;
201 return 0;
204 static void discard_unused_subtrees(struct cache_tree *it)
206 struct cache_tree_sub **down = it->down;
207 int nr = it->subtree_nr;
208 int dst, src;
209 for (dst = src = 0; src < nr; src++) {
210 struct cache_tree_sub *s = down[src];
211 if (s->used)
212 down[dst++] = s;
213 else {
214 cache_tree_free(&s->cache_tree);
215 free(s);
216 it->subtree_nr--;
221 int cache_tree_fully_valid(struct cache_tree *it)
223 int i;
224 if (!it)
225 return 0;
226 if (it->entry_count < 0 || !has_sha1_file(it->sha1))
227 return 0;
228 for (i = 0; i < it->subtree_nr; i++) {
229 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
230 return 0;
232 return 1;
235 static int update_one(struct cache_tree *it,
236 struct cache_entry **cache,
237 int entries,
238 const char *base,
239 int baselen,
240 int missing_ok,
241 int dryrun)
243 struct strbuf buffer;
244 int i;
246 if (0 <= it->entry_count && has_sha1_file(it->sha1))
247 return it->entry_count;
250 * We first scan for subtrees and update them; we start by
251 * marking existing subtrees -- the ones that are unmarked
252 * should not be in the result.
254 for (i = 0; i < it->subtree_nr; i++)
255 it->down[i]->used = 0;
258 * Find the subtrees and update them.
260 for (i = 0; i < entries; i++) {
261 struct cache_entry *ce = cache[i];
262 struct cache_tree_sub *sub;
263 const char *path, *slash;
264 int pathlen, sublen, subcnt;
266 path = ce->name;
267 pathlen = ce_namelen(ce);
268 if (pathlen <= baselen || memcmp(base, path, baselen))
269 break; /* at the end of this level */
271 slash = strchr(path + baselen, '/');
272 if (!slash)
273 continue;
275 * a/bbb/c (base = a/, slash = /c)
276 * ==>
277 * path+baselen = bbb/c, sublen = 3
279 sublen = slash - (path + baselen);
280 sub = find_subtree(it, path + baselen, sublen, 1);
281 if (!sub->cache_tree)
282 sub->cache_tree = cache_tree();
283 subcnt = update_one(sub->cache_tree,
284 cache + i, entries - i,
285 path,
286 baselen + sublen + 1,
287 missing_ok,
288 dryrun);
289 if (subcnt < 0)
290 return subcnt;
291 i += subcnt - 1;
292 sub->used = 1;
295 discard_unused_subtrees(it);
298 * Then write out the tree object for this level.
300 strbuf_init(&buffer, 8192);
302 for (i = 0; i < entries; i++) {
303 struct cache_entry *ce = cache[i];
304 struct cache_tree_sub *sub;
305 const char *path, *slash;
306 int pathlen, entlen;
307 const unsigned char *sha1;
308 unsigned mode;
310 path = ce->name;
311 pathlen = ce_namelen(ce);
312 if (pathlen <= baselen || memcmp(base, path, baselen))
313 break; /* at the end of this level */
315 slash = strchr(path + baselen, '/');
316 if (slash) {
317 entlen = slash - (path + baselen);
318 sub = find_subtree(it, path + baselen, entlen, 0);
319 if (!sub)
320 die("cache-tree.c: '%.*s' in '%s' not found",
321 entlen, path + baselen, path);
322 i += sub->cache_tree->entry_count - 1;
323 sha1 = sub->cache_tree->sha1;
324 mode = S_IFDIR;
326 else {
327 sha1 = ce->sha1;
328 mode = ce->ce_mode;
329 entlen = pathlen - baselen;
331 if (mode != S_IFGITLINK && !missing_ok && !has_sha1_file(sha1))
332 return error("invalid object %06o %s for '%.*s'",
333 mode, sha1_to_hex(sha1), entlen+baselen, path);
335 if (ce->ce_flags & CE_REMOVE)
336 continue; /* entry being removed */
338 strbuf_grow(&buffer, entlen + 100);
339 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
340 strbuf_add(&buffer, sha1, 20);
342 #if DEBUG
343 fprintf(stderr, "cache-tree update-one %o %.*s\n",
344 mode, entlen, path + baselen);
345 #endif
348 if (dryrun)
349 hash_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
350 else if (write_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1)) {
351 strbuf_release(&buffer);
352 return -1;
355 strbuf_release(&buffer);
356 it->entry_count = i;
357 #if DEBUG
358 fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
359 it->entry_count, it->subtree_nr,
360 sha1_to_hex(it->sha1));
361 #endif
362 return i;
365 int cache_tree_update(struct cache_tree *it,
366 struct cache_entry **cache,
367 int entries,
368 int missing_ok,
369 int dryrun)
371 int i;
372 i = verify_cache(cache, entries);
373 if (i)
374 return i;
375 i = update_one(it, cache, entries, "", 0, missing_ok, dryrun);
376 if (i < 0)
377 return i;
378 return 0;
381 static void write_one(struct strbuf *buffer, struct cache_tree *it,
382 const char *path, int pathlen)
384 int i;
386 /* One "cache-tree" entry consists of the following:
387 * path (NUL terminated)
388 * entry_count, subtree_nr ("%d %d\n")
389 * tree-sha1 (missing if invalid)
390 * subtree_nr "cache-tree" entries for subtrees.
392 strbuf_grow(buffer, pathlen + 100);
393 strbuf_add(buffer, path, pathlen);
394 strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
396 #if DEBUG
397 if (0 <= it->entry_count)
398 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
399 pathlen, path, it->entry_count, it->subtree_nr,
400 sha1_to_hex(it->sha1));
401 else
402 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
403 pathlen, path, it->subtree_nr);
404 #endif
406 if (0 <= it->entry_count) {
407 strbuf_add(buffer, it->sha1, 20);
409 for (i = 0; i < it->subtree_nr; i++) {
410 struct cache_tree_sub *down = it->down[i];
411 if (i) {
412 struct cache_tree_sub *prev = it->down[i-1];
413 if (subtree_name_cmp(down->name, down->namelen,
414 prev->name, prev->namelen) <= 0)
415 die("fatal - unsorted cache subtree");
417 write_one(buffer, down->cache_tree, down->name, down->namelen);
421 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
423 write_one(sb, root, "", 0);
426 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
428 const char *buf = *buffer;
429 unsigned long size = *size_p;
430 const char *cp;
431 char *ep;
432 struct cache_tree *it;
433 int i, subtree_nr;
435 it = NULL;
436 /* skip name, but make sure name exists */
437 while (size && *buf) {
438 size--;
439 buf++;
441 if (!size)
442 goto free_return;
443 buf++; size--;
444 it = cache_tree();
446 cp = buf;
447 it->entry_count = strtol(cp, &ep, 10);
448 if (cp == ep)
449 goto free_return;
450 cp = ep;
451 subtree_nr = strtol(cp, &ep, 10);
452 if (cp == ep)
453 goto free_return;
454 while (size && *buf && *buf != '\n') {
455 size--;
456 buf++;
458 if (!size)
459 goto free_return;
460 buf++; size--;
461 if (0 <= it->entry_count) {
462 if (size < 20)
463 goto free_return;
464 hashcpy(it->sha1, (const unsigned char*)buf);
465 buf += 20;
466 size -= 20;
469 #if DEBUG
470 if (0 <= it->entry_count)
471 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
472 *buffer, it->entry_count, subtree_nr,
473 sha1_to_hex(it->sha1));
474 else
475 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
476 *buffer, subtree_nr);
477 #endif
480 * Just a heuristic -- we do not add directories that often but
481 * we do not want to have to extend it immediately when we do,
482 * hence +2.
484 it->subtree_alloc = subtree_nr + 2;
485 it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
486 for (i = 0; i < subtree_nr; i++) {
487 /* read each subtree */
488 struct cache_tree *sub;
489 struct cache_tree_sub *subtree;
490 const char *name = buf;
492 sub = read_one(&buf, &size);
493 if (!sub)
494 goto free_return;
495 subtree = cache_tree_sub(it, name);
496 subtree->cache_tree = sub;
498 if (subtree_nr != it->subtree_nr)
499 die("cache-tree: internal error");
500 *buffer = buf;
501 *size_p = size;
502 return it;
504 free_return:
505 cache_tree_free(&it);
506 return NULL;
509 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
511 if (buffer[0])
512 return NULL; /* not the whole tree */
513 return read_one(&buffer, &size);
516 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
518 if (!it)
519 return NULL;
520 while (*path) {
521 const char *slash;
522 struct cache_tree_sub *sub;
524 slash = strchr(path, '/');
525 if (!slash)
526 slash = path + strlen(path);
527 /* between path and slash is the name of the
528 * subtree to look for.
530 sub = find_subtree(it, path, slash - path, 0);
531 if (!sub)
532 return NULL;
533 it = sub->cache_tree;
534 if (slash)
535 while (*slash && *slash == '/')
536 slash++;
537 if (!slash || !*slash)
538 return it; /* prefix ended with slashes */
539 path = slash;
541 return it;
544 int write_cache_as_tree(unsigned char *sha1, int flags, const char *prefix)
546 int entries, was_valid, newfd;
547 struct lock_file *lock_file;
550 * We can't free this memory, it becomes part of a linked list
551 * parsed atexit()
553 lock_file = xcalloc(1, sizeof(struct lock_file));
555 newfd = hold_locked_index(lock_file, 1);
557 entries = read_cache();
558 if (entries < 0)
559 return WRITE_TREE_UNREADABLE_INDEX;
560 if (flags & WRITE_TREE_IGNORE_CACHE_TREE)
561 cache_tree_free(&(active_cache_tree));
563 if (!active_cache_tree)
564 active_cache_tree = cache_tree();
566 was_valid = cache_tree_fully_valid(active_cache_tree);
567 if (!was_valid) {
568 int missing_ok = flags & WRITE_TREE_MISSING_OK;
570 if (cache_tree_update(active_cache_tree,
571 active_cache, active_nr,
572 missing_ok, 0) < 0)
573 return WRITE_TREE_UNMERGED_INDEX;
574 if (0 <= newfd) {
575 if (!write_cache(newfd, active_cache, active_nr) &&
576 !commit_lock_file(lock_file))
577 newfd = -1;
579 /* Not being able to write is fine -- we are only interested
580 * in updating the cache-tree part, and if the next caller
581 * ends up using the old index with unupdated cache-tree part
582 * it misses the work we did here, but that is just a
583 * performance penalty and not a big deal.
587 if (prefix) {
588 struct cache_tree *subtree =
589 cache_tree_find(active_cache_tree, prefix);
590 if (!subtree)
591 return WRITE_TREE_PREFIX_ERROR;
592 hashcpy(sha1, subtree->sha1);
594 else
595 hashcpy(sha1, active_cache_tree->sha1);
597 if (0 <= newfd)
598 rollback_lock_file(lock_file);
600 return 0;
603 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
605 struct tree_desc desc;
606 struct name_entry entry;
607 int cnt;
609 hashcpy(it->sha1, tree->object.sha1);
610 init_tree_desc(&desc, tree->buffer, tree->size);
611 cnt = 0;
612 while (tree_entry(&desc, &entry)) {
613 if (!S_ISDIR(entry.mode))
614 cnt++;
615 else {
616 struct cache_tree_sub *sub;
617 struct tree *subtree = lookup_tree(entry.sha1);
618 if (!subtree->object.parsed)
619 parse_tree(subtree);
620 sub = cache_tree_sub(it, entry.path);
621 sub->cache_tree = cache_tree();
622 prime_cache_tree_rec(sub->cache_tree, subtree);
623 cnt += sub->cache_tree->entry_count;
626 it->entry_count = cnt;
629 void prime_cache_tree(struct cache_tree **it, struct tree *tree)
631 cache_tree_free(it);
632 *it = cache_tree();
633 prime_cache_tree_rec(*it, tree);
637 * find the cache_tree that corresponds to the current level without
638 * exploding the full path into textual form. The root of the
639 * cache tree is given as "root", and our current level is "info".
640 * (1) When at root level, info->prev is NULL, so it is "root" itself.
641 * (2) Otherwise, find the cache_tree that corresponds to one level
642 * above us, and find ourselves in there.
644 static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
645 struct traverse_info *info)
647 struct cache_tree *our_parent;
649 if (!info->prev)
650 return root;
651 our_parent = find_cache_tree_from_traversal(root, info->prev);
652 return cache_tree_find(our_parent, info->name.path);
655 int cache_tree_matches_traversal(struct cache_tree *root,
656 struct name_entry *ent,
657 struct traverse_info *info)
659 struct cache_tree *it;
661 it = find_cache_tree_from_traversal(root, info);
662 it = cache_tree_find(it, ent->path);
663 if (it && it->entry_count > 0 && !hashcmp(ent->sha1, it->sha1))
664 return it->entry_count;
665 return 0;