Merge branch 'rs/fsck-duplicate-names-in-trees'
[git] / cache-tree.c
1 #include "cache.h"
2 #include "lockfile.h"
3 #include "tree.h"
4 #include "tree-walk.h"
5 #include "cache-tree.h"
6 #include "object-store.h"
7 #include "replace-object.h"
8 #include "promisor-remote.h"
9
10 #ifndef DEBUG_CACHE_TREE
11 #define DEBUG_CACHE_TREE 0
12 #endif
13
14 struct cache_tree *cache_tree(void)
15 {
16         struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
17         it->entry_count = -1;
18         return it;
19 }
20
21 void cache_tree_free(struct cache_tree **it_p)
22 {
23         int i;
24         struct cache_tree *it = *it_p;
25
26         if (!it)
27                 return;
28         for (i = 0; i < it->subtree_nr; i++)
29                 if (it->down[i]) {
30                         cache_tree_free(&it->down[i]->cache_tree);
31                         free(it->down[i]);
32                 }
33         free(it->down);
34         free(it);
35         *it_p = NULL;
36 }
37
38 static int subtree_name_cmp(const char *one, int onelen,
39                             const char *two, int twolen)
40 {
41         if (onelen < twolen)
42                 return -1;
43         if (twolen < onelen)
44                 return 1;
45         return memcmp(one, two, onelen);
46 }
47
48 static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
49 {
50         struct cache_tree_sub **down = it->down;
51         int lo, hi;
52         lo = 0;
53         hi = it->subtree_nr;
54         while (lo < hi) {
55                 int mi = lo + (hi - lo) / 2;
56                 struct cache_tree_sub *mdl = down[mi];
57                 int cmp = subtree_name_cmp(path, pathlen,
58                                            mdl->name, mdl->namelen);
59                 if (!cmp)
60                         return mi;
61                 if (cmp < 0)
62                         hi = mi;
63                 else
64                         lo = mi + 1;
65         }
66         return -lo-1;
67 }
68
69 static struct cache_tree_sub *find_subtree(struct cache_tree *it,
70                                            const char *path,
71                                            int pathlen,
72                                            int create)
73 {
74         struct cache_tree_sub *down;
75         int pos = subtree_pos(it, path, pathlen);
76         if (0 <= pos)
77                 return it->down[pos];
78         if (!create)
79                 return NULL;
80
81         pos = -pos-1;
82         ALLOC_GROW(it->down, it->subtree_nr + 1, it->subtree_alloc);
83         it->subtree_nr++;
84
85         FLEX_ALLOC_MEM(down, name, path, pathlen);
86         down->cache_tree = NULL;
87         down->namelen = pathlen;
88
89         if (pos < it->subtree_nr)
90                 MOVE_ARRAY(it->down + pos + 1, it->down + pos,
91                            it->subtree_nr - pos - 1);
92         it->down[pos] = down;
93         return down;
94 }
95
96 struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
97 {
98         int pathlen = strlen(path);
99         return find_subtree(it, path, pathlen, 1);
100 }
101
102 static int do_invalidate_path(struct cache_tree *it, const char *path)
103 {
104         /* a/b/c
105          * ==> invalidate self
106          * ==> find "a", have it invalidate "b/c"
107          * a
108          * ==> invalidate self
109          * ==> if "a" exists as a subtree, remove it.
110          */
111         const char *slash;
112         int namelen;
113         struct cache_tree_sub *down;
114
115 #if DEBUG_CACHE_TREE
116         fprintf(stderr, "cache-tree invalidate <%s>\n", path);
117 #endif
118
119         if (!it)
120                 return 0;
121         slash = strchrnul(path, '/');
122         namelen = slash - path;
123         it->entry_count = -1;
124         if (!*slash) {
125                 int pos;
126                 pos = subtree_pos(it, path, namelen);
127                 if (0 <= pos) {
128                         cache_tree_free(&it->down[pos]->cache_tree);
129                         free(it->down[pos]);
130                         /* 0 1 2 3 4 5
131                          *       ^     ^subtree_nr = 6
132                          *       pos
133                          * move 4 and 5 up one place (2 entries)
134                          * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
135                          */
136                         MOVE_ARRAY(it->down + pos, it->down + pos + 1,
137                                    it->subtree_nr - pos - 1);
138                         it->subtree_nr--;
139                 }
140                 return 1;
141         }
142         down = find_subtree(it, path, namelen, 0);
143         if (down)
144                 do_invalidate_path(down->cache_tree, slash + 1);
145         return 1;
146 }
147
148 void cache_tree_invalidate_path(struct index_state *istate, const char *path)
149 {
150         if (do_invalidate_path(istate->cache_tree, path))
151                 istate->cache_changed |= CACHE_TREE_CHANGED;
152 }
153
154 static int verify_cache(struct cache_entry **cache,
155                         int entries, int flags)
156 {
157         int i, funny;
158         int silent = flags & WRITE_TREE_SILENT;
159
160         /* Verify that the tree is merged */
161         funny = 0;
162         for (i = 0; i < entries; i++) {
163                 const struct cache_entry *ce = cache[i];
164                 if (ce_stage(ce)) {
165                         if (silent)
166                                 return -1;
167                         if (10 < ++funny) {
168                                 fprintf(stderr, "...\n");
169                                 break;
170                         }
171                         fprintf(stderr, "%s: unmerged (%s)\n",
172                                 ce->name, oid_to_hex(&ce->oid));
173                 }
174         }
175         if (funny)
176                 return -1;
177
178         /* Also verify that the cache does not have path and path/file
179          * at the same time.  At this point we know the cache has only
180          * stage 0 entries.
181          */
182         funny = 0;
183         for (i = 0; i < entries - 1; i++) {
184                 /* path/file always comes after path because of the way
185                  * the cache is sorted.  Also path can appear only once,
186                  * which means conflicting one would immediately follow.
187                  */
188                 const char *this_name = cache[i]->name;
189                 const char *next_name = cache[i+1]->name;
190                 int this_len = strlen(this_name);
191                 if (this_len < strlen(next_name) &&
192                     strncmp(this_name, next_name, this_len) == 0 &&
193                     next_name[this_len] == '/') {
194                         if (10 < ++funny) {
195                                 fprintf(stderr, "...\n");
196                                 break;
197                         }
198                         fprintf(stderr, "You have both %s and %s\n",
199                                 this_name, next_name);
200                 }
201         }
202         if (funny)
203                 return -1;
204         return 0;
205 }
206
207 static void discard_unused_subtrees(struct cache_tree *it)
208 {
209         struct cache_tree_sub **down = it->down;
210         int nr = it->subtree_nr;
211         int dst, src;
212         for (dst = src = 0; src < nr; src++) {
213                 struct cache_tree_sub *s = down[src];
214                 if (s->used)
215                         down[dst++] = s;
216                 else {
217                         cache_tree_free(&s->cache_tree);
218                         free(s);
219                         it->subtree_nr--;
220                 }
221         }
222 }
223
224 int cache_tree_fully_valid(struct cache_tree *it)
225 {
226         int i;
227         if (!it)
228                 return 0;
229         if (it->entry_count < 0 || !has_object_file(&it->oid))
230                 return 0;
231         for (i = 0; i < it->subtree_nr; i++) {
232                 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
233                         return 0;
234         }
235         return 1;
236 }
237
238 static int update_one(struct cache_tree *it,
239                       struct cache_entry **cache,
240                       int entries,
241                       const char *base,
242                       int baselen,
243                       int *skip_count,
244                       int flags)
245 {
246         struct strbuf buffer;
247         int missing_ok = flags & WRITE_TREE_MISSING_OK;
248         int dryrun = flags & WRITE_TREE_DRY_RUN;
249         int repair = flags & WRITE_TREE_REPAIR;
250         int to_invalidate = 0;
251         int i;
252
253         assert(!(dryrun && repair));
254
255         *skip_count = 0;
256
257         if (0 <= it->entry_count && has_object_file(&it->oid))
258                 return it->entry_count;
259
260         /*
261          * We first scan for subtrees and update them; we start by
262          * marking existing subtrees -- the ones that are unmarked
263          * should not be in the result.
264          */
265         for (i = 0; i < it->subtree_nr; i++)
266                 it->down[i]->used = 0;
267
268         /*
269          * Find the subtrees and update them.
270          */
271         i = 0;
272         while (i < entries) {
273                 const struct cache_entry *ce = cache[i];
274                 struct cache_tree_sub *sub;
275                 const char *path, *slash;
276                 int pathlen, sublen, subcnt, subskip;
277
278                 path = ce->name;
279                 pathlen = ce_namelen(ce);
280                 if (pathlen <= baselen || memcmp(base, path, baselen))
281                         break; /* at the end of this level */
282
283                 slash = strchr(path + baselen, '/');
284                 if (!slash) {
285                         i++;
286                         continue;
287                 }
288                 /*
289                  * a/bbb/c (base = a/, slash = /c)
290                  * ==>
291                  * path+baselen = bbb/c, sublen = 3
292                  */
293                 sublen = slash - (path + baselen);
294                 sub = find_subtree(it, path + baselen, sublen, 1);
295                 if (!sub->cache_tree)
296                         sub->cache_tree = cache_tree();
297                 subcnt = update_one(sub->cache_tree,
298                                     cache + i, entries - i,
299                                     path,
300                                     baselen + sublen + 1,
301                                     &subskip,
302                                     flags);
303                 if (subcnt < 0)
304                         return subcnt;
305                 if (!subcnt)
306                         die("index cache-tree records empty sub-tree");
307                 i += subcnt;
308                 sub->count = subcnt; /* to be used in the next loop */
309                 *skip_count += subskip;
310                 sub->used = 1;
311         }
312
313         discard_unused_subtrees(it);
314
315         /*
316          * Then write out the tree object for this level.
317          */
318         strbuf_init(&buffer, 8192);
319
320         i = 0;
321         while (i < entries) {
322                 const struct cache_entry *ce = cache[i];
323                 struct cache_tree_sub *sub = NULL;
324                 const char *path, *slash;
325                 int pathlen, entlen;
326                 const struct object_id *oid;
327                 unsigned mode;
328                 int expected_missing = 0;
329                 int contains_ita = 0;
330                 int ce_missing_ok;
331
332                 path = ce->name;
333                 pathlen = ce_namelen(ce);
334                 if (pathlen <= baselen || memcmp(base, path, baselen))
335                         break; /* at the end of this level */
336
337                 slash = strchr(path + baselen, '/');
338                 if (slash) {
339                         entlen = slash - (path + baselen);
340                         sub = find_subtree(it, path + baselen, entlen, 0);
341                         if (!sub)
342                                 die("cache-tree.c: '%.*s' in '%s' not found",
343                                     entlen, path + baselen, path);
344                         i += sub->count;
345                         oid = &sub->cache_tree->oid;
346                         mode = S_IFDIR;
347                         contains_ita = sub->cache_tree->entry_count < 0;
348                         if (contains_ita) {
349                                 to_invalidate = 1;
350                                 expected_missing = 1;
351                         }
352                 }
353                 else {
354                         oid = &ce->oid;
355                         mode = ce->ce_mode;
356                         entlen = pathlen - baselen;
357                         i++;
358                 }
359
360                 ce_missing_ok = mode == S_IFGITLINK || missing_ok ||
361                         (has_promisor_remote() &&
362                          ce_skip_worktree(ce));
363                 if (is_null_oid(oid) ||
364                     (!ce_missing_ok && !has_object_file(oid))) {
365                         strbuf_release(&buffer);
366                         if (expected_missing)
367                                 return -1;
368                         return error("invalid object %06o %s for '%.*s'",
369                                 mode, oid_to_hex(oid), entlen+baselen, path);
370                 }
371
372                 /*
373                  * CE_REMOVE entries are removed before the index is
374                  * written to disk. Skip them to remain consistent
375                  * with the future on-disk index.
376                  */
377                 if (ce->ce_flags & CE_REMOVE) {
378                         *skip_count = *skip_count + 1;
379                         continue;
380                 }
381
382                 /*
383                  * CE_INTENT_TO_ADD entries exist on on-disk index but
384                  * they are not part of generated trees. Invalidate up
385                  * to root to force cache-tree users to read elsewhere.
386                  */
387                 if (!sub && ce_intent_to_add(ce)) {
388                         to_invalidate = 1;
389                         continue;
390                 }
391
392                 /*
393                  * "sub" can be an empty tree if all subentries are i-t-a.
394                  */
395                 if (contains_ita && is_empty_tree_oid(oid))
396                         continue;
397
398                 strbuf_grow(&buffer, entlen + 100);
399                 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
400                 strbuf_add(&buffer, oid->hash, the_hash_algo->rawsz);
401
402 #if DEBUG_CACHE_TREE
403                 fprintf(stderr, "cache-tree update-one %o %.*s\n",
404                         mode, entlen, path + baselen);
405 #endif
406         }
407
408         if (repair) {
409                 struct object_id oid;
410                 hash_object_file(the_hash_algo, buffer.buf, buffer.len,
411                                  tree_type, &oid);
412                 if (has_object_file_with_flags(&oid, OBJECT_INFO_SKIP_FETCH_OBJECT))
413                         oidcpy(&it->oid, &oid);
414                 else
415                         to_invalidate = 1;
416         } else if (dryrun) {
417                 hash_object_file(the_hash_algo, buffer.buf, buffer.len,
418                                  tree_type, &it->oid);
419         } else if (write_object_file(buffer.buf, buffer.len, tree_type,
420                                      &it->oid)) {
421                 strbuf_release(&buffer);
422                 return -1;
423         }
424
425         strbuf_release(&buffer);
426         it->entry_count = to_invalidate ? -1 : i - *skip_count;
427 #if DEBUG_CACHE_TREE
428         fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
429                 it->entry_count, it->subtree_nr,
430                 oid_to_hex(&it->oid));
431 #endif
432         return i;
433 }
434
435 int cache_tree_update(struct index_state *istate, int flags)
436 {
437         struct cache_tree *it = istate->cache_tree;
438         struct cache_entry **cache = istate->cache;
439         int entries = istate->cache_nr;
440         int skip, i = verify_cache(cache, entries, flags);
441
442         if (i)
443                 return i;
444         trace_performance_enter();
445         i = update_one(it, cache, entries, "", 0, &skip, flags);
446         trace_performance_leave("cache_tree_update");
447         if (i < 0)
448                 return i;
449         istate->cache_changed |= CACHE_TREE_CHANGED;
450         return 0;
451 }
452
453 static void write_one(struct strbuf *buffer, struct cache_tree *it,
454                       const char *path, int pathlen)
455 {
456         int i;
457
458         /* One "cache-tree" entry consists of the following:
459          * path (NUL terminated)
460          * entry_count, subtree_nr ("%d %d\n")
461          * tree-sha1 (missing if invalid)
462          * subtree_nr "cache-tree" entries for subtrees.
463          */
464         strbuf_grow(buffer, pathlen + 100);
465         strbuf_add(buffer, path, pathlen);
466         strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
467
468 #if DEBUG_CACHE_TREE
469         if (0 <= it->entry_count)
470                 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
471                         pathlen, path, it->entry_count, it->subtree_nr,
472                         oid_to_hex(&it->oid));
473         else
474                 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
475                         pathlen, path, it->subtree_nr);
476 #endif
477
478         if (0 <= it->entry_count) {
479                 strbuf_add(buffer, it->oid.hash, the_hash_algo->rawsz);
480         }
481         for (i = 0; i < it->subtree_nr; i++) {
482                 struct cache_tree_sub *down = it->down[i];
483                 if (i) {
484                         struct cache_tree_sub *prev = it->down[i-1];
485                         if (subtree_name_cmp(down->name, down->namelen,
486                                              prev->name, prev->namelen) <= 0)
487                                 die("fatal - unsorted cache subtree");
488                 }
489                 write_one(buffer, down->cache_tree, down->name, down->namelen);
490         }
491 }
492
493 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
494 {
495         write_one(sb, root, "", 0);
496 }
497
498 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
499 {
500         const char *buf = *buffer;
501         unsigned long size = *size_p;
502         const char *cp;
503         char *ep;
504         struct cache_tree *it;
505         int i, subtree_nr;
506         const unsigned rawsz = the_hash_algo->rawsz;
507
508         it = NULL;
509         /* skip name, but make sure name exists */
510         while (size && *buf) {
511                 size--;
512                 buf++;
513         }
514         if (!size)
515                 goto free_return;
516         buf++; size--;
517         it = cache_tree();
518
519         cp = buf;
520         it->entry_count = strtol(cp, &ep, 10);
521         if (cp == ep)
522                 goto free_return;
523         cp = ep;
524         subtree_nr = strtol(cp, &ep, 10);
525         if (cp == ep)
526                 goto free_return;
527         while (size && *buf && *buf != '\n') {
528                 size--;
529                 buf++;
530         }
531         if (!size)
532                 goto free_return;
533         buf++; size--;
534         if (0 <= it->entry_count) {
535                 if (size < rawsz)
536                         goto free_return;
537                 oidread(&it->oid, (const unsigned char *)buf);
538                 buf += rawsz;
539                 size -= rawsz;
540         }
541
542 #if DEBUG_CACHE_TREE
543         if (0 <= it->entry_count)
544                 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
545                         *buffer, it->entry_count, subtree_nr,
546                         oid_to_hex(&it->oid));
547         else
548                 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
549                         *buffer, subtree_nr);
550 #endif
551
552         /*
553          * Just a heuristic -- we do not add directories that often but
554          * we do not want to have to extend it immediately when we do,
555          * hence +2.
556          */
557         it->subtree_alloc = subtree_nr + 2;
558         it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
559         for (i = 0; i < subtree_nr; i++) {
560                 /* read each subtree */
561                 struct cache_tree *sub;
562                 struct cache_tree_sub *subtree;
563                 const char *name = buf;
564
565                 sub = read_one(&buf, &size);
566                 if (!sub)
567                         goto free_return;
568                 subtree = cache_tree_sub(it, name);
569                 subtree->cache_tree = sub;
570         }
571         if (subtree_nr != it->subtree_nr)
572                 die("cache-tree: internal error");
573         *buffer = buf;
574         *size_p = size;
575         return it;
576
577  free_return:
578         cache_tree_free(&it);
579         return NULL;
580 }
581
582 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
583 {
584         if (buffer[0])
585                 return NULL; /* not the whole tree */
586         return read_one(&buffer, &size);
587 }
588
589 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
590 {
591         if (!it)
592                 return NULL;
593         while (*path) {
594                 const char *slash;
595                 struct cache_tree_sub *sub;
596
597                 slash = strchrnul(path, '/');
598                 /*
599                  * Between path and slash is the name of the subtree
600                  * to look for.
601                  */
602                 sub = find_subtree(it, path, slash - path, 0);
603                 if (!sub)
604                         return NULL;
605                 it = sub->cache_tree;
606
607                 path = slash;
608                 while (*path == '/')
609                         path++;
610         }
611         return it;
612 }
613
614 static int write_index_as_tree_internal(struct object_id *oid,
615                                         struct index_state *index_state,
616                                         int cache_tree_valid,
617                                         int flags,
618                                         const char *prefix)
619 {
620         if (flags & WRITE_TREE_IGNORE_CACHE_TREE) {
621                 cache_tree_free(&index_state->cache_tree);
622                 cache_tree_valid = 0;
623         }
624
625         if (!index_state->cache_tree)
626                 index_state->cache_tree = cache_tree();
627
628         if (!cache_tree_valid && cache_tree_update(index_state, flags) < 0)
629                 return WRITE_TREE_UNMERGED_INDEX;
630
631         if (prefix) {
632                 struct cache_tree *subtree;
633                 subtree = cache_tree_find(index_state->cache_tree, prefix);
634                 if (!subtree)
635                         return WRITE_TREE_PREFIX_ERROR;
636                 oidcpy(oid, &subtree->oid);
637         }
638         else
639                 oidcpy(oid, &index_state->cache_tree->oid);
640
641         return 0;
642 }
643
644 struct tree* write_in_core_index_as_tree(struct repository *repo) {
645         struct object_id o;
646         int was_valid, ret;
647
648         struct index_state *index_state = repo->index;
649         was_valid = index_state->cache_tree &&
650                     cache_tree_fully_valid(index_state->cache_tree);
651
652         ret = write_index_as_tree_internal(&o, index_state, was_valid, 0, NULL);
653         if (ret == WRITE_TREE_UNMERGED_INDEX) {
654                 int i;
655                 fprintf(stderr, "BUG: There are unmerged index entries:\n");
656                 for (i = 0; i < index_state->cache_nr; i++) {
657                         const struct cache_entry *ce = index_state->cache[i];
658                         if (ce_stage(ce))
659                                 fprintf(stderr, "BUG: %d %.*s\n", ce_stage(ce),
660                                         (int)ce_namelen(ce), ce->name);
661                 }
662                 BUG("unmerged index entries when writing inmemory index");
663         }
664
665         return lookup_tree(repo, &index_state->cache_tree->oid);
666 }
667
668
669 int write_index_as_tree(struct object_id *oid, struct index_state *index_state, const char *index_path, int flags, const char *prefix)
670 {
671         int entries, was_valid;
672         struct lock_file lock_file = LOCK_INIT;
673         int ret;
674
675         hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR);
676
677         entries = read_index_from(index_state, index_path, get_git_dir());
678         if (entries < 0) {
679                 ret = WRITE_TREE_UNREADABLE_INDEX;
680                 goto out;
681         }
682
683         was_valid = !(flags & WRITE_TREE_IGNORE_CACHE_TREE) &&
684                     index_state->cache_tree &&
685                     cache_tree_fully_valid(index_state->cache_tree);
686
687         ret = write_index_as_tree_internal(oid, index_state, was_valid, flags,
688                                            prefix);
689         if (!ret && !was_valid) {
690                 write_locked_index(index_state, &lock_file, COMMIT_LOCK);
691                 /* Not being able to write is fine -- we are only interested
692                  * in updating the cache-tree part, and if the next caller
693                  * ends up using the old index with unupdated cache-tree part
694                  * it misses the work we did here, but that is just a
695                  * performance penalty and not a big deal.
696                  */
697         }
698
699 out:
700         rollback_lock_file(&lock_file);
701         return ret;
702 }
703
704 static void prime_cache_tree_rec(struct repository *r,
705                                  struct cache_tree *it,
706                                  struct tree *tree)
707 {
708         struct tree_desc desc;
709         struct name_entry entry;
710         int cnt;
711
712         oidcpy(&it->oid, &tree->object.oid);
713         init_tree_desc(&desc, tree->buffer, tree->size);
714         cnt = 0;
715         while (tree_entry(&desc, &entry)) {
716                 if (!S_ISDIR(entry.mode))
717                         cnt++;
718                 else {
719                         struct cache_tree_sub *sub;
720                         struct tree *subtree = lookup_tree(r, &entry.oid);
721                         if (!subtree->object.parsed)
722                                 parse_tree(subtree);
723                         sub = cache_tree_sub(it, entry.path);
724                         sub->cache_tree = cache_tree();
725                         prime_cache_tree_rec(r, sub->cache_tree, subtree);
726                         cnt += sub->cache_tree->entry_count;
727                 }
728         }
729         it->entry_count = cnt;
730 }
731
732 void prime_cache_tree(struct repository *r,
733                       struct index_state *istate,
734                       struct tree *tree)
735 {
736         cache_tree_free(&istate->cache_tree);
737         istate->cache_tree = cache_tree();
738         prime_cache_tree_rec(r, istate->cache_tree, tree);
739         istate->cache_changed |= CACHE_TREE_CHANGED;
740 }
741
742 /*
743  * find the cache_tree that corresponds to the current level without
744  * exploding the full path into textual form.  The root of the
745  * cache tree is given as "root", and our current level is "info".
746  * (1) When at root level, info->prev is NULL, so it is "root" itself.
747  * (2) Otherwise, find the cache_tree that corresponds to one level
748  *     above us, and find ourselves in there.
749  */
750 static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,
751                                                          struct traverse_info *info)
752 {
753         struct cache_tree *our_parent;
754
755         if (!info->prev)
756                 return root;
757         our_parent = find_cache_tree_from_traversal(root, info->prev);
758         return cache_tree_find(our_parent, info->name);
759 }
760
761 int cache_tree_matches_traversal(struct cache_tree *root,
762                                  struct name_entry *ent,
763                                  struct traverse_info *info)
764 {
765         struct cache_tree *it;
766
767         it = find_cache_tree_from_traversal(root, info);
768         it = cache_tree_find(it, ent->path);
769         if (it && it->entry_count > 0 && oideq(&ent->oid, &it->oid))
770                 return it->entry_count;
771         return 0;
772 }
773
774 static void verify_one(struct repository *r,
775                        struct index_state *istate,
776                        struct cache_tree *it,
777                        struct strbuf *path)
778 {
779         int i, pos, len = path->len;
780         struct strbuf tree_buf = STRBUF_INIT;
781         struct object_id new_oid;
782
783         for (i = 0; i < it->subtree_nr; i++) {
784                 strbuf_addf(path, "%s/", it->down[i]->name);
785                 verify_one(r, istate, it->down[i]->cache_tree, path);
786                 strbuf_setlen(path, len);
787         }
788
789         if (it->entry_count < 0 ||
790             /* no verification on tests (t7003) that replace trees */
791             lookup_replace_object(r, &it->oid) != &it->oid)
792                 return;
793
794         if (path->len) {
795                 pos = index_name_pos(istate, path->buf, path->len);
796                 pos = -pos - 1;
797         } else {
798                 pos = 0;
799         }
800
801         i = 0;
802         while (i < it->entry_count) {
803                 struct cache_entry *ce = istate->cache[pos + i];
804                 const char *slash;
805                 struct cache_tree_sub *sub = NULL;
806                 const struct object_id *oid;
807                 const char *name;
808                 unsigned mode;
809                 int entlen;
810
811                 if (ce->ce_flags & (CE_STAGEMASK | CE_INTENT_TO_ADD | CE_REMOVE))
812                         BUG("%s with flags 0x%x should not be in cache-tree",
813                             ce->name, ce->ce_flags);
814                 name = ce->name + path->len;
815                 slash = strchr(name, '/');
816                 if (slash) {
817                         entlen = slash - name;
818                         sub = find_subtree(it, ce->name + path->len, entlen, 0);
819                         if (!sub || sub->cache_tree->entry_count < 0)
820                                 BUG("bad subtree '%.*s'", entlen, name);
821                         oid = &sub->cache_tree->oid;
822                         mode = S_IFDIR;
823                         i += sub->cache_tree->entry_count;
824                 } else {
825                         oid = &ce->oid;
826                         mode = ce->ce_mode;
827                         entlen = ce_namelen(ce) - path->len;
828                         i++;
829                 }
830                 strbuf_addf(&tree_buf, "%o %.*s%c", mode, entlen, name, '\0');
831                 strbuf_add(&tree_buf, oid->hash, r->hash_algo->rawsz);
832         }
833         hash_object_file(r->hash_algo, tree_buf.buf, tree_buf.len, tree_type,
834                          &new_oid);
835         if (!oideq(&new_oid, &it->oid))
836                 BUG("cache-tree for path %.*s does not match. "
837                     "Expected %s got %s", len, path->buf,
838                     oid_to_hex(&new_oid), oid_to_hex(&it->oid));
839         strbuf_setlen(path, len);
840         strbuf_release(&tree_buf);
841 }
842
843 void cache_tree_verify(struct repository *r, struct index_state *istate)
844 {
845         struct strbuf path = STRBUF_INIT;
846
847         if (!istate->cache_tree)
848                 return;
849         verify_one(r, istate, istate->cache_tree, &path);
850         strbuf_release(&path);
851 }