Merge branch 'jc/maint-1.6.1-add-u-remove-conflicted' into maint-1.6.1
[git] / cache-tree.c
1 #include "cache.h"
2 #include "tree.h"
3 #include "cache-tree.h"
4
5 #ifndef DEBUG
6 #define DEBUG 0
7 #endif
8
9 struct cache_tree *cache_tree(void)
10 {
11         struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
12         it->entry_count = -1;
13         return it;
14 }
15
16 void cache_tree_free(struct cache_tree **it_p)
17 {
18         int i;
19         struct cache_tree *it = *it_p;
20
21         if (!it)
22                 return;
23         for (i = 0; i < it->subtree_nr; i++)
24                 if (it->down[i])
25                         cache_tree_free(&it->down[i]->cache_tree);
26         free(it->down);
27         free(it);
28         *it_p = NULL;
29 }
30
31 static int subtree_name_cmp(const char *one, int onelen,
32                             const char *two, int twolen)
33 {
34         if (onelen < twolen)
35                 return -1;
36         if (twolen < onelen)
37                 return 1;
38         return memcmp(one, two, onelen);
39 }
40
41 static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
42 {
43         struct cache_tree_sub **down = it->down;
44         int lo, hi;
45         lo = 0;
46         hi = it->subtree_nr;
47         while (lo < hi) {
48                 int mi = (lo + hi) / 2;
49                 struct cache_tree_sub *mdl = down[mi];
50                 int cmp = subtree_name_cmp(path, pathlen,
51                                            mdl->name, mdl->namelen);
52                 if (!cmp)
53                         return mi;
54                 if (cmp < 0)
55                         hi = mi;
56                 else
57                         lo = mi + 1;
58         }
59         return -lo-1;
60 }
61
62 static struct cache_tree_sub *find_subtree(struct cache_tree *it,
63                                            const char *path,
64                                            int pathlen,
65                                            int create)
66 {
67         struct cache_tree_sub *down;
68         int pos = subtree_pos(it, path, pathlen);
69         if (0 <= pos)
70                 return it->down[pos];
71         if (!create)
72                 return NULL;
73
74         pos = -pos-1;
75         if (it->subtree_alloc <= it->subtree_nr) {
76                 it->subtree_alloc = alloc_nr(it->subtree_alloc);
77                 it->down = xrealloc(it->down, it->subtree_alloc *
78                                     sizeof(*it->down));
79         }
80         it->subtree_nr++;
81
82         down = xmalloc(sizeof(*down) + pathlen + 1);
83         down->cache_tree = NULL;
84         down->namelen = pathlen;
85         memcpy(down->name, path, pathlen);
86         down->name[pathlen] = 0;
87
88         if (pos < it->subtree_nr)
89                 memmove(it->down + pos + 1,
90                         it->down + pos,
91                         sizeof(down) * (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 void cache_tree_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
116         fprintf(stderr, "cache-tree invalidate <%s>\n", path);
117 #endif
118
119         if (!it)
120                 return;
121         slash = strchr(path, '/');
122         it->entry_count = -1;
123         if (!slash) {
124                 int pos;
125                 namelen = strlen(path);
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                         memmove(it->down+pos, it->down+pos+1,
137                                 sizeof(struct cache_tree_sub *) *
138                                 (it->subtree_nr - pos - 1));
139                         it->subtree_nr--;
140                 }
141                 return;
142         }
143         namelen = slash - path;
144         down = find_subtree(it, path, namelen, 0);
145         if (down)
146                 cache_tree_invalidate_path(down->cache_tree, slash + 1);
147 }
148
149 static int verify_cache(struct cache_entry **cache,
150                         int entries)
151 {
152         int i, funny;
153
154         /* Verify that the tree is merged */
155         funny = 0;
156         for (i = 0; i < entries; i++) {
157                 struct cache_entry *ce = cache[i];
158                 if (ce_stage(ce) || (ce->ce_flags & CE_INTENT_TO_ADD)) {
159                         if (10 < ++funny) {
160                                 fprintf(stderr, "...\n");
161                                 break;
162                         }
163                         if (ce_stage(ce))
164                                 fprintf(stderr, "%s: unmerged (%s)\n",
165                                         ce->name, sha1_to_hex(ce->sha1));
166                         else
167                                 fprintf(stderr, "%s: not added yet\n",
168                                         ce->name);
169                 }
170         }
171         if (funny)
172                 return -1;
173
174         /* Also verify that the cache does not have path and path/file
175          * at the same time.  At this point we know the cache has only
176          * stage 0 entries.
177          */
178         funny = 0;
179         for (i = 0; i < entries - 1; i++) {
180                 /* path/file always comes after path because of the way
181                  * the cache is sorted.  Also path can appear only once,
182                  * which means conflicting one would immediately follow.
183                  */
184                 const char *this_name = cache[i]->name;
185                 const char *next_name = cache[i+1]->name;
186                 int this_len = strlen(this_name);
187                 if (this_len < strlen(next_name) &&
188                     strncmp(this_name, next_name, this_len) == 0 &&
189                     next_name[this_len] == '/') {
190                         if (10 < ++funny) {
191                                 fprintf(stderr, "...\n");
192                                 break;
193                         }
194                         fprintf(stderr, "You have both %s and %s\n",
195                                 this_name, next_name);
196                 }
197         }
198         if (funny)
199                 return -1;
200         return 0;
201 }
202
203 static void discard_unused_subtrees(struct cache_tree *it)
204 {
205         struct cache_tree_sub **down = it->down;
206         int nr = it->subtree_nr;
207         int dst, src;
208         for (dst = src = 0; src < nr; src++) {
209                 struct cache_tree_sub *s = down[src];
210                 if (s->used)
211                         down[dst++] = s;
212                 else {
213                         cache_tree_free(&s->cache_tree);
214                         free(s);
215                         it->subtree_nr--;
216                 }
217         }
218 }
219
220 int cache_tree_fully_valid(struct cache_tree *it)
221 {
222         int i;
223         if (!it)
224                 return 0;
225         if (it->entry_count < 0 || !has_sha1_file(it->sha1))
226                 return 0;
227         for (i = 0; i < it->subtree_nr; i++) {
228                 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
229                         return 0;
230         }
231         return 1;
232 }
233
234 static int update_one(struct cache_tree *it,
235                       struct cache_entry **cache,
236                       int entries,
237                       const char *base,
238                       int baselen,
239                       int missing_ok,
240                       int dryrun)
241 {
242         struct strbuf buffer;
243         int i;
244
245         if (0 <= it->entry_count && has_sha1_file(it->sha1))
246                 return it->entry_count;
247
248         /*
249          * We first scan for subtrees and update them; we start by
250          * marking existing subtrees -- the ones that are unmarked
251          * should not be in the result.
252          */
253         for (i = 0; i < it->subtree_nr; i++)
254                 it->down[i]->used = 0;
255
256         /*
257          * Find the subtrees and update them.
258          */
259         for (i = 0; i < entries; i++) {
260                 struct cache_entry *ce = cache[i];
261                 struct cache_tree_sub *sub;
262                 const char *path, *slash;
263                 int pathlen, sublen, subcnt;
264
265                 path = ce->name;
266                 pathlen = ce_namelen(ce);
267                 if (pathlen <= baselen || memcmp(base, path, baselen))
268                         break; /* at the end of this level */
269
270                 slash = strchr(path + baselen, '/');
271                 if (!slash)
272                         continue;
273                 /*
274                  * a/bbb/c (base = a/, slash = /c)
275                  * ==>
276                  * path+baselen = bbb/c, sublen = 3
277                  */
278                 sublen = slash - (path + baselen);
279                 sub = find_subtree(it, path + baselen, sublen, 1);
280                 if (!sub->cache_tree)
281                         sub->cache_tree = cache_tree();
282                 subcnt = update_one(sub->cache_tree,
283                                     cache + i, entries - i,
284                                     path,
285                                     baselen + sublen + 1,
286                                     missing_ok,
287                                     dryrun);
288                 if (subcnt < 0)
289                         return subcnt;
290                 i += subcnt - 1;
291                 sub->used = 1;
292         }
293
294         discard_unused_subtrees(it);
295
296         /*
297          * Then write out the tree object for this level.
298          */
299         strbuf_init(&buffer, 8192);
300
301         for (i = 0; i < entries; i++) {
302                 struct cache_entry *ce = cache[i];
303                 struct cache_tree_sub *sub;
304                 const char *path, *slash;
305                 int pathlen, entlen;
306                 const unsigned char *sha1;
307                 unsigned mode;
308
309                 path = ce->name;
310                 pathlen = ce_namelen(ce);
311                 if (pathlen <= baselen || memcmp(base, path, baselen))
312                         break; /* at the end of this level */
313
314                 slash = strchr(path + baselen, '/');
315                 if (slash) {
316                         entlen = slash - (path + baselen);
317                         sub = find_subtree(it, path + baselen, entlen, 0);
318                         if (!sub)
319                                 die("cache-tree.c: '%.*s' in '%s' not found",
320                                     entlen, path + baselen, path);
321                         i += sub->cache_tree->entry_count - 1;
322                         sha1 = sub->cache_tree->sha1;
323                         mode = S_IFDIR;
324                 }
325                 else {
326                         sha1 = ce->sha1;
327                         mode = ce->ce_mode;
328                         entlen = pathlen - baselen;
329                 }
330                 if (mode != S_IFGITLINK && !missing_ok && !has_sha1_file(sha1))
331                         return error("invalid object %s", sha1_to_hex(sha1));
332
333                 if (ce->ce_flags & CE_REMOVE)
334                         continue; /* entry being removed */
335
336                 strbuf_grow(&buffer, entlen + 100);
337                 strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
338                 strbuf_add(&buffer, sha1, 20);
339
340 #if DEBUG
341                 fprintf(stderr, "cache-tree update-one %o %.*s\n",
342                         mode, entlen, path + baselen);
343 #endif
344         }
345
346         if (dryrun)
347                 hash_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
348         else if (write_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1)) {
349                 strbuf_release(&buffer);
350                 return -1;
351         }
352
353         strbuf_release(&buffer);
354         it->entry_count = i;
355 #if DEBUG
356         fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
357                 it->entry_count, it->subtree_nr,
358                 sha1_to_hex(it->sha1));
359 #endif
360         return i;
361 }
362
363 int cache_tree_update(struct cache_tree *it,
364                       struct cache_entry **cache,
365                       int entries,
366                       int missing_ok,
367                       int dryrun)
368 {
369         int i;
370         i = verify_cache(cache, entries);
371         if (i)
372                 return i;
373         i = update_one(it, cache, entries, "", 0, missing_ok, dryrun);
374         if (i < 0)
375                 return i;
376         return 0;
377 }
378
379 static void write_one(struct strbuf *buffer, struct cache_tree *it,
380                       const char *path, int pathlen)
381 {
382         int i;
383
384         /* One "cache-tree" entry consists of the following:
385          * path (NUL terminated)
386          * entry_count, subtree_nr ("%d %d\n")
387          * tree-sha1 (missing if invalid)
388          * subtree_nr "cache-tree" entries for subtrees.
389          */
390         strbuf_grow(buffer, pathlen + 100);
391         strbuf_add(buffer, path, pathlen);
392         strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
393
394 #if DEBUG
395         if (0 <= it->entry_count)
396                 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
397                         pathlen, path, it->entry_count, it->subtree_nr,
398                         sha1_to_hex(it->sha1));
399         else
400                 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
401                         pathlen, path, it->subtree_nr);
402 #endif
403
404         if (0 <= it->entry_count) {
405                 strbuf_add(buffer, it->sha1, 20);
406         }
407         for (i = 0; i < it->subtree_nr; i++) {
408                 struct cache_tree_sub *down = it->down[i];
409                 if (i) {
410                         struct cache_tree_sub *prev = it->down[i-1];
411                         if (subtree_name_cmp(down->name, down->namelen,
412                                              prev->name, prev->namelen) <= 0)
413                                 die("fatal - unsorted cache subtree");
414                 }
415                 write_one(buffer, down->cache_tree, down->name, down->namelen);
416         }
417 }
418
419 void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
420 {
421         write_one(sb, root, "", 0);
422 }
423
424 static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
425 {
426         const char *buf = *buffer;
427         unsigned long size = *size_p;
428         const char *cp;
429         char *ep;
430         struct cache_tree *it;
431         int i, subtree_nr;
432
433         it = NULL;
434         /* skip name, but make sure name exists */
435         while (size && *buf) {
436                 size--;
437                 buf++;
438         }
439         if (!size)
440                 goto free_return;
441         buf++; size--;
442         it = cache_tree();
443
444         cp = buf;
445         it->entry_count = strtol(cp, &ep, 10);
446         if (cp == ep)
447                 goto free_return;
448         cp = ep;
449         subtree_nr = strtol(cp, &ep, 10);
450         if (cp == ep)
451                 goto free_return;
452         while (size && *buf && *buf != '\n') {
453                 size--;
454                 buf++;
455         }
456         if (!size)
457                 goto free_return;
458         buf++; size--;
459         if (0 <= it->entry_count) {
460                 if (size < 20)
461                         goto free_return;
462                 hashcpy(it->sha1, (const unsigned char*)buf);
463                 buf += 20;
464                 size -= 20;
465         }
466
467 #if DEBUG
468         if (0 <= it->entry_count)
469                 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
470                         *buffer, it->entry_count, subtree_nr,
471                         sha1_to_hex(it->sha1));
472         else
473                 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
474                         *buffer, subtree_nr);
475 #endif
476
477         /*
478          * Just a heuristic -- we do not add directories that often but
479          * we do not want to have to extend it immediately when we do,
480          * hence +2.
481          */
482         it->subtree_alloc = subtree_nr + 2;
483         it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
484         for (i = 0; i < subtree_nr; i++) {
485                 /* read each subtree */
486                 struct cache_tree *sub;
487                 struct cache_tree_sub *subtree;
488                 const char *name = buf;
489
490                 sub = read_one(&buf, &size);
491                 if (!sub)
492                         goto free_return;
493                 subtree = cache_tree_sub(it, name);
494                 subtree->cache_tree = sub;
495         }
496         if (subtree_nr != it->subtree_nr)
497                 die("cache-tree: internal error");
498         *buffer = buf;
499         *size_p = size;
500         return it;
501
502  free_return:
503         cache_tree_free(&it);
504         return NULL;
505 }
506
507 struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
508 {
509         if (buffer[0])
510                 return NULL; /* not the whole tree */
511         return read_one(&buffer, &size);
512 }
513
514 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
515 {
516         while (*path) {
517                 const char *slash;
518                 struct cache_tree_sub *sub;
519
520                 slash = strchr(path, '/');
521                 if (!slash)
522                         slash = path + strlen(path);
523                 /* between path and slash is the name of the
524                  * subtree to look for.
525                  */
526                 sub = find_subtree(it, path, slash - path, 0);
527                 if (!sub)
528                         return NULL;
529                 it = sub->cache_tree;
530                 if (slash)
531                         while (*slash && *slash == '/')
532                                 slash++;
533                 if (!slash || !*slash)
534                         return it; /* prefix ended with slashes */
535                 path = slash;
536         }
537         return it;
538 }
539
540 int write_cache_as_tree(unsigned char *sha1, int missing_ok, const char *prefix)
541 {
542         int entries, was_valid, newfd;
543
544         /*
545          * We can't free this memory, it becomes part of a linked list
546          * parsed atexit()
547          */
548         struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
549
550         newfd = hold_locked_index(lock_file, 1);
551
552         entries = read_cache();
553         if (entries < 0)
554                 return WRITE_TREE_UNREADABLE_INDEX;
555
556         if (!active_cache_tree)
557                 active_cache_tree = cache_tree();
558
559         was_valid = cache_tree_fully_valid(active_cache_tree);
560
561         if (!was_valid) {
562                 if (cache_tree_update(active_cache_tree,
563                                       active_cache, active_nr,
564                                       missing_ok, 0) < 0)
565                         return WRITE_TREE_UNMERGED_INDEX;
566                 if (0 <= newfd) {
567                         if (!write_cache(newfd, active_cache, active_nr) &&
568                             !commit_lock_file(lock_file))
569                                 newfd = -1;
570                 }
571                 /* Not being able to write is fine -- we are only interested
572                  * in updating the cache-tree part, and if the next caller
573                  * ends up using the old index with unupdated cache-tree part
574                  * it misses the work we did here, but that is just a
575                  * performance penalty and not a big deal.
576                  */
577         }
578
579         if (prefix) {
580                 struct cache_tree *subtree =
581                         cache_tree_find(active_cache_tree, prefix);
582                 if (!subtree)
583                         return WRITE_TREE_PREFIX_ERROR;
584                 hashcpy(sha1, subtree->sha1);
585         }
586         else
587                 hashcpy(sha1, active_cache_tree->sha1);
588
589         if (0 <= newfd)
590                 rollback_lock_file(lock_file);
591
592         return 0;
593 }