Merge branch 'dj/fetch-tagopt' into maint
[git/mjg.git] / cache-tree.c
blobc60cf9140dd18254886ea14de763738630f95973
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 strbuf_release(&buffer);
333 return error("invalid object %06o %s for '%.*s'",
334 mode, sha1_to_hex(sha1), entlen+baselen, path);
337 if (ce->ce_flags & CE_REMOVE)
338 continue; /* entry being removed */
340 strbuf_grow(&buffer, entlen + 100);
341 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
342 strbuf_add(&buffer, sha1, 20);
344 #if DEBUG
345 fprintf(stderr, "cache-tree update-one %o %.*s\n",
346 mode, entlen, path + baselen);
347 #endif
350 if (dryrun)
351 hash_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
352 else if (write_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1)) {
353 strbuf_release(&buffer);
354 return -1;
357 strbuf_release(&buffer);
358 it->entry_count = i;
359 #if DEBUG
360 fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
361 it->entry_count, it->subtree_nr,
362 sha1_to_hex(it->sha1));
363 #endif
364 return i;
367 int cache_tree_update(struct cache_tree *it,
368 struct cache_entry **cache,
369 int entries,
370 int missing_ok,
371 int dryrun)
373 int i;
374 i = verify_cache(cache, entries);
375 if (i)
376 return i;
377 i = update_one(it, cache, entries, "", 0, missing_ok, dryrun);
378 if (i < 0)
379 return i;
380 return 0;
383 static void write_one(struct strbuf *buffer, struct cache_tree *it,
384 const char *path, int pathlen)
386 int i;
388 /* One "cache-tree" entry consists of the following:
389 * path (NUL terminated)
390 * entry_count, subtree_nr ("%d %d\n")
391 * tree-sha1 (missing if invalid)
392 * subtree_nr "cache-tree" entries for subtrees.
394 strbuf_grow(buffer, pathlen + 100);
395 strbuf_add(buffer, path, pathlen);
396 strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
398 #if DEBUG
399 if (0 <= it->entry_count)
400 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
401 pathlen, path, it->entry_count, it->subtree_nr,
402 sha1_to_hex(it->sha1));
403 else
404 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
405 pathlen, path, it->subtree_nr);
406 #endif
408 if (0 <= it->entry_count) {
409 strbuf_add(buffer, it->sha1, 20);
411 for (i = 0; i < it->subtree_nr; i++) {
412 struct cache_tree_sub *down = it->down[i];
413 if (i) {
414 struct cache_tree_sub *prev = it->down[i-1];
415 if (subtree_name_cmp(down->name, down->namelen,
416 prev->name, prev->namelen) <= 0)
417 die("fatal - unsorted cache subtree");
419 write_one(buffer, down->cache_tree, down->name, down->namelen);
423 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
425 write_one(sb, root, "", 0);
428 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
430 const char *buf = *buffer;
431 unsigned long size = *size_p;
432 const char *cp;
433 char *ep;
434 struct cache_tree *it;
435 int i, subtree_nr;
437 it = NULL;
438 /* skip name, but make sure name exists */
439 while (size && *buf) {
440 size--;
441 buf++;
443 if (!size)
444 goto free_return;
445 buf++; size--;
446 it = cache_tree();
448 cp = buf;
449 it->entry_count = strtol(cp, &ep, 10);
450 if (cp == ep)
451 goto free_return;
452 cp = ep;
453 subtree_nr = strtol(cp, &ep, 10);
454 if (cp == ep)
455 goto free_return;
456 while (size && *buf && *buf != '\n') {
457 size--;
458 buf++;
460 if (!size)
461 goto free_return;
462 buf++; size--;
463 if (0 <= it->entry_count) {
464 if (size < 20)
465 goto free_return;
466 hashcpy(it->sha1, (const unsigned char*)buf);
467 buf += 20;
468 size -= 20;
471 #if DEBUG
472 if (0 <= it->entry_count)
473 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
474 *buffer, it->entry_count, subtree_nr,
475 sha1_to_hex(it->sha1));
476 else
477 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
478 *buffer, subtree_nr);
479 #endif
482 * Just a heuristic -- we do not add directories that often but
483 * we do not want to have to extend it immediately when we do,
484 * hence +2.
486 it->subtree_alloc = subtree_nr + 2;
487 it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
488 for (i = 0; i < subtree_nr; i++) {
489 /* read each subtree */
490 struct cache_tree *sub;
491 struct cache_tree_sub *subtree;
492 const char *name = buf;
494 sub = read_one(&buf, &size);
495 if (!sub)
496 goto free_return;
497 subtree = cache_tree_sub(it, name);
498 subtree->cache_tree = sub;
500 if (subtree_nr != it->subtree_nr)
501 die("cache-tree: internal error");
502 *buffer = buf;
503 *size_p = size;
504 return it;
506 free_return:
507 cache_tree_free(&it);
508 return NULL;
511 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
513 if (buffer[0])
514 return NULL; /* not the whole tree */
515 return read_one(&buffer, &size);
518 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
520 if (!it)
521 return NULL;
522 while (*path) {
523 const char *slash;
524 struct cache_tree_sub *sub;
526 slash = strchr(path, '/');
527 if (!slash)
528 slash = path + strlen(path);
529 /* between path and slash is the name of the
530 * subtree to look for.
532 sub = find_subtree(it, path, slash - path, 0);
533 if (!sub)
534 return NULL;
535 it = sub->cache_tree;
536 if (slash)
537 while (*slash && *slash == '/')
538 slash++;
539 if (!slash || !*slash)
540 return it; /* prefix ended with slashes */
541 path = slash;
543 return it;
546 int write_cache_as_tree(unsigned char *sha1, int flags, const char *prefix)
548 int entries, was_valid, newfd;
549 struct lock_file *lock_file;
552 * We can't free this memory, it becomes part of a linked list
553 * parsed atexit()
555 lock_file = xcalloc(1, sizeof(struct lock_file));
557 newfd = hold_locked_index(lock_file, 1);
559 entries = read_cache();
560 if (entries < 0)
561 return WRITE_TREE_UNREADABLE_INDEX;
562 if (flags & WRITE_TREE_IGNORE_CACHE_TREE)
563 cache_tree_free(&(active_cache_tree));
565 if (!active_cache_tree)
566 active_cache_tree = cache_tree();
568 was_valid = cache_tree_fully_valid(active_cache_tree);
569 if (!was_valid) {
570 int missing_ok = flags & WRITE_TREE_MISSING_OK;
572 if (cache_tree_update(active_cache_tree,
573 active_cache, active_nr,
574 missing_ok, 0) < 0)
575 return WRITE_TREE_UNMERGED_INDEX;
576 if (0 <= newfd) {
577 if (!write_cache(newfd, active_cache, active_nr) &&
578 !commit_lock_file(lock_file))
579 newfd = -1;
581 /* Not being able to write is fine -- we are only interested
582 * in updating the cache-tree part, and if the next caller
583 * ends up using the old index with unupdated cache-tree part
584 * it misses the work we did here, but that is just a
585 * performance penalty and not a big deal.
589 if (prefix) {
590 struct cache_tree *subtree =
591 cache_tree_find(active_cache_tree, prefix);
592 if (!subtree)
593 return WRITE_TREE_PREFIX_ERROR;
594 hashcpy(sha1, subtree->sha1);
596 else
597 hashcpy(sha1, active_cache_tree->sha1);
599 if (0 <= newfd)
600 rollback_lock_file(lock_file);
602 return 0;
605 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
607 struct tree_desc desc;
608 struct name_entry entry;
609 int cnt;
611 hashcpy(it->sha1, tree->object.sha1);
612 init_tree_desc(&desc, tree->buffer, tree->size);
613 cnt = 0;
614 while (tree_entry(&desc, &entry)) {
615 if (!S_ISDIR(entry.mode))
616 cnt++;
617 else {
618 struct cache_tree_sub *sub;
619 struct tree *subtree = lookup_tree(entry.sha1);
620 if (!subtree->object.parsed)
621 parse_tree(subtree);
622 sub = cache_tree_sub(it, entry.path);
623 sub->cache_tree = cache_tree();
624 prime_cache_tree_rec(sub->cache_tree, subtree);
625 cnt += sub->cache_tree->entry_count;
628 it->entry_count = cnt;
631 void prime_cache_tree(struct cache_tree **it, struct tree *tree)
633 cache_tree_free(it);
634 *it = cache_tree();
635 prime_cache_tree_rec(*it, tree);
639 * find the cache_tree that corresponds to the current level without
640 * exploding the full path into textual form. The root of the
641 * cache tree is given as "root", and our current level is "info".
642 * (1) When at root level, info->prev is NULL, so it is "root" itself.
643 * (2) Otherwise, find the cache_tree that corresponds to one level
644 * above us, and find ourselves in there.
646 static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
647 struct traverse_info *info)
649 struct cache_tree *our_parent;
651 if (!info->prev)
652 return root;
653 our_parent = find_cache_tree_from_traversal(root, info->prev);
654 return cache_tree_find(our_parent, info->name.path);
657 int cache_tree_matches_traversal(struct cache_tree *root,
658 struct name_entry *ent,
659 struct traverse_info *info)
661 struct cache_tree *it;
663 it = find_cache_tree_from_traversal(root, info);
664 it = cache_tree_find(it, ent->path);
665 if (it && it->entry_count > 0 && !hashcmp(ent->sha1, it->sha1))
666 return it->entry_count;
667 return 0;