1#include "cache.h"
2#include "tree.h"
3#include "cache-tree.h"
4#define DEBUG 0
6struct cache_tree *cache_tree(void)
8{
9 struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
10 it->entry_count = -1;
11 return it;
12}
13void cache_tree_free(struct cache_tree **it_p)
15{
16 int i;
17 struct cache_tree *it = *it_p;
18 if (!it)
20 return;
21 for (i = 0; i < it->subtree_nr; i++)
22 if (it->down[i])
23 cache_tree_free(&it->down[i]->cache_tree);
24 free(it->down);
25 free(it);
26 *it_p = NULL;
27}
28static int subtree_name_cmp(const char *one, int onelen,
30 const char *two, int twolen)
31{
32 if (onelen < twolen)
33 return -1;
34 if (twolen < onelen)
35 return 1;
36 return memcmp(one, two, onelen);
37}
38static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
40{
41 struct cache_tree_sub **down = it->down;
42 int lo, hi;
43 lo = 0;
44 hi = it->subtree_nr;
45 while (lo < hi) {
46 int mi = (lo + hi) / 2;
47 struct cache_tree_sub *mdl = down[mi];
48 int cmp = subtree_name_cmp(path, pathlen,
49 mdl->name, mdl->namelen);
50 if (!cmp)
51 return mi;
52 if (cmp < 0)
53 hi = mi;
54 else
55 lo = mi + 1;
56 }
57 return -lo-1;
58}
59static struct cache_tree_sub *find_subtree(struct cache_tree *it,
61 const char *path,
62 int pathlen,
63 int create)
64{
65 struct cache_tree_sub *down;
66 int pos = subtree_pos(it, path, pathlen);
67 if (0 <= pos)
68 return it->down[pos];
69 if (!create)
70 return NULL;
71 pos = -pos-1;
73 if (it->subtree_alloc <= it->subtree_nr) {
74 it->subtree_alloc = alloc_nr(it->subtree_alloc);
75 it->down = xrealloc(it->down, it->subtree_alloc *
76 sizeof(*it->down));
77 }
78 it->subtree_nr++;
79 down = xmalloc(sizeof(*down) + pathlen + 1);
81 down->cache_tree = NULL;
82 down->namelen = pathlen;
83 memcpy(down->name, path, pathlen);
84 down->name[pathlen] = 0;
85 if (pos < it->subtree_nr)
87 memmove(it->down + pos + 1,
88 it->down + pos,
89 sizeof(down) * (it->subtree_nr - pos - 1));
90 it->down[pos] = down;
91 return down;
92}
93struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
95{
96 int pathlen = strlen(path);
97 return find_subtree(it, path, pathlen, 1);
98}
99void cache_tree_invalidate_path(struct cache_tree *it, const char *path)
101{
102 /* a/b/c
103 * ==> invalidate self
104 * ==> find "a", have it invalidate "b/c"
105 * a
106 * ==> invalidate self
107 * ==> if "a" exists as a subtree, remove it.
108 */
109 const char *slash;
110 int namelen;
111 struct cache_tree_sub *down;
112#if DEBUG
114 fprintf(stderr, "cache-tree invalidate <%s>\n", path);
115#endif
116 if (!it)
118 return;
119 slash = strchr(path, '/');
120 it->entry_count = -1;
121 if (!slash) {
122 int pos;
123 namelen = strlen(path);
124 pos = subtree_pos(it, path, namelen);
125 if (0 <= pos) {
126 cache_tree_free(&it->down[pos]->cache_tree);
127 free(it->down[pos]);
128 /* 0 1 2 3 4 5
129 * ^ ^subtree_nr = 6
130 * pos
131 * move 4 and 5 up one place (2 entries)
132 * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
133 */
134 memmove(it->down+pos, it->down+pos+1,
135 sizeof(struct cache_tree_sub *) *
136 (it->subtree_nr - pos - 1));
137 it->subtree_nr--;
138 }
139 return;
140 }
141 namelen = slash - path;
142 down = find_subtree(it, path, namelen, 0);
143 if (down)
144 cache_tree_invalidate_path(down->cache_tree, slash + 1);
145}
146static int verify_cache(struct cache_entry **cache,
148 int entries)
149{
150 int i, funny;
151 /* Verify that the tree is merged */
153 funny = 0;
154 for (i = 0; i < entries; i++) {
155 struct cache_entry *ce = cache[i];
156 if (ce_stage(ce)) {
157 if (10 < ++funny) {
158 fprintf(stderr, "...\n");
159 break;
160 }
161 fprintf(stderr, "%s: unmerged (%s)\n",
162 ce->name, sha1_to_hex(ce->sha1));
163 }
164 }
165 if (funny)
166 return -1;
167 /* Also verify that the cache does not have path and path/file
169 * at the same time. At this point we know the cache has only
170 * stage 0 entries.
171 */
172 funny = 0;
173 for (i = 0; i < entries - 1; i++) {
174 /* path/file always comes after path because of the way
175 * the cache is sorted. Also path can appear only once,
176 * which means conflicting one would immediately follow.
177 */
178 const char *this_name = cache[i]->name;
179 const char *next_name = cache[i+1]->name;
180 int this_len = strlen(this_name);
181 if (this_len < strlen(next_name) &&
182 strncmp(this_name, next_name, this_len) == 0 &&
183 next_name[this_len] == '/') {
184 if (10 < ++funny) {
185 fprintf(stderr, "...\n");
186 break;
187 }
188 fprintf(stderr, "You have both %s and %s\n",
189 this_name, next_name);
190 }
191 }
192 if (funny)
193 return -1;
194 return 0;
195}
196static void discard_unused_subtrees(struct cache_tree *it)
198{
199 struct cache_tree_sub **down = it->down;
200 int nr = it->subtree_nr;
201 int dst, src;
202 for (dst = src = 0; src < nr; src++) {
203 struct cache_tree_sub *s = down[src];
204 if (s->used)
205 down[dst++] = s;
206 else {
207 cache_tree_free(&s->cache_tree);
208 free(s);
209 it->subtree_nr--;
210 }
211 }
212}
213int cache_tree_fully_valid(struct cache_tree *it)
215{
216 int i;
217 if (!it)
218 return 0;
219 if (it->entry_count < 0 || !has_sha1_file(it->sha1))
220 return 0;
221 for (i = 0; i < it->subtree_nr; i++) {
222 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
223 return 0;
224 }
225 return 1;
226}
227static int update_one(struct cache_tree *it,
229 struct cache_entry **cache,
230 int entries,
231 const char *base,
232 int baselen,
233 int missing_ok,
234 int dryrun)
235{
236 unsigned long size, offset;
237 char *buffer;
238 int i;
239 if (0 <= it->entry_count && has_sha1_file(it->sha1))
241 return it->entry_count;
242 /*
244 * We first scan for subtrees and update them; we start by
245 * marking existing subtrees -- the ones that are unmarked
246 * should not be in the result.
247 */
248 for (i = 0; i < it->subtree_nr; i++)
249 it->down[i]->used = 0;
250 /*
252 * Find the subtrees and update them.
253 */
254 for (i = 0; i < entries; i++) {
255 struct cache_entry *ce = cache[i];
256 struct cache_tree_sub *sub;
257 const char *path, *slash;
258 int pathlen, sublen, subcnt;
259 path = ce->name;
261 pathlen = ce_namelen(ce);
262 if (pathlen <= baselen || memcmp(base, path, baselen))
263 break; /* at the end of this level */
264 slash = strchr(path + baselen, '/');
266 if (!slash)
267 continue;
268 /*
269 * a/bbb/c (base = a/, slash = /c)
270 * ==>
271 * path+baselen = bbb/c, sublen = 3
272 */
273 sublen = slash - (path + baselen);
274 sub = find_subtree(it, path + baselen, sublen, 1);
275 if (!sub->cache_tree)
276 sub->cache_tree = cache_tree();
277 subcnt = update_one(sub->cache_tree,
278 cache + i, entries - i,
279 path,
280 baselen + sublen + 1,
281 missing_ok,
282 dryrun);
283 i += subcnt - 1;
284 sub->used = 1;
285 }
286 discard_unused_subtrees(it);
288 /*
290 * Then write out the tree object for this level.
291 */
292 size = 8192;
293 buffer = xmalloc(size);
294 offset = 0;
295 for (i = 0; i < entries; i++) {
297 struct cache_entry *ce = cache[i];
298 struct cache_tree_sub *sub;
299 const char *path, *slash;
300 int pathlen, entlen;
301 const unsigned char *sha1;
302 unsigned mode;
303 path = ce->name;
305 pathlen = ce_namelen(ce);
306 if (pathlen <= baselen || memcmp(base, path, baselen))
307 break; /* at the end of this level */
308 slash = strchr(path + baselen, '/');
310 if (slash) {
311 entlen = slash - (path + baselen);
312 sub = find_subtree(it, path + baselen, entlen, 0);
313 if (!sub)
314 die("cache-tree.c: '%.*s' in '%s' not found",
315 entlen, path + baselen, path);
316 i += sub->cache_tree->entry_count - 1;
317 sha1 = sub->cache_tree->sha1;
318 mode = S_IFDIR;
319 }
320 else {
321 sha1 = ce->sha1;
322 mode = ntohl(ce->ce_mode);
323 entlen = pathlen - baselen;
324 }
325 if (!missing_ok && !has_sha1_file(sha1))
326 return error("invalid object %s", sha1_to_hex(sha1));
327 if (!ce->ce_mode)
329 continue; /* entry being removed */
330 if (size < offset + entlen + 100) {
332 size = alloc_nr(offset + entlen + 100);
333 buffer = xrealloc(buffer, size);
334 }
335 offset += sprintf(buffer + offset,
336 "%o %.*s", mode, entlen, path + baselen);
337 buffer[offset++] = 0;
338 memcpy(buffer + offset, sha1, 20);
339 offset += 20;
340#if DEBUG
342 fprintf(stderr, "cache-tree update-one %o %.*s\n",
343 mode, entlen, path + baselen);
344#endif
345 }
346 if (dryrun) {
348 unsigned char hdr[200];
349 int hdrlen;
350 write_sha1_file_prepare(buffer, offset, tree_type, it->sha1,
351 hdr, &hdrlen);
352 }
353 else
354 write_sha1_file(buffer, offset, tree_type, it->sha1);
355 free(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;
363}
364int cache_tree_update(struct cache_tree *it,
366 struct cache_entry **cache,
367 int entries,
368 int missing_ok,
369 int dryrun)
370{
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;
379}
380static void *write_one(struct cache_tree *it,
382 char *path,
383 int pathlen,
384 char *buffer,
385 unsigned long *size,
386 unsigned long *offset)
387{
388 int i;
389 /* 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.
395 */
396 if (*size < *offset + pathlen + 100) {
397 *size = alloc_nr(*offset + pathlen + 100);
398 buffer = xrealloc(buffer, *size);
399 }
400 *offset += sprintf(buffer + *offset, "%.*s%c%d %d\n",
401 pathlen, path, 0,
402 it->entry_count, it->subtree_nr);
403#if DEBUG
405 if (0 <= it->entry_count)
406 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
407 pathlen, path, it->entry_count, it->subtree_nr,
408 sha1_to_hex(it->sha1));
409 else
410 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
411 pathlen, path, it->subtree_nr);
412#endif
413 if (0 <= it->entry_count) {
415 memcpy(buffer + *offset, it->sha1, 20);
416 *offset += 20;
417 }
418 for (i = 0; i < it->subtree_nr; i++) {
419 struct cache_tree_sub *down = it->down[i];
420 if (i) {
421 struct cache_tree_sub *prev = it->down[i-1];
422 if (subtree_name_cmp(down->name, down->namelen,
423 prev->name, prev->namelen) <= 0)
424 die("fatal - unsorted cache subtree");
425 }
426 buffer = write_one(down->cache_tree, down->name, down->namelen,
427 buffer, size, offset);
428 }
429 return buffer;
430}
431void *cache_tree_write(struct cache_tree *root, unsigned long *size_p)
433{
434 char path[PATH_MAX];
435 unsigned long size = 8192;
436 char *buffer = xmalloc(size);
437 *size_p = 0;
439 path[0] = 0;
440 return write_one(root, path, 0, buffer, &size, size_p);
441}
442static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
444{
445 const char *buf = *buffer;
446 unsigned long size = *size_p;
447 const char *cp;
448 char *ep;
449 struct cache_tree *it;
450 int i, subtree_nr;
451 it = NULL;
453 /* skip name, but make sure name exists */
454 while (size && *buf) {
455 size--;
456 buf++;
457 }
458 if (!size)
459 goto free_return;
460 buf++; size--;
461 it = cache_tree();
462 cp = buf;
464 it->entry_count = strtol(cp, &ep, 10);
465 if (cp == ep)
466 goto free_return;
467 cp = ep;
468 subtree_nr = strtol(cp, &ep, 10);
469 if (cp == ep)
470 goto free_return;
471 while (size && *buf && *buf != '\n') {
472 size--;
473 buf++;
474 }
475 if (!size)
476 goto free_return;
477 buf++; size--;
478 if (0 <= it->entry_count) {
479 if (size < 20)
480 goto free_return;
481 memcpy(it->sha1, buf, 20);
482 buf += 20;
483 size -= 20;
484 }
485#if DEBUG
487 if (0 <= it->entry_count)
488 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
489 *buffer, it->entry_count, subtree_nr,
490 sha1_to_hex(it->sha1));
491 else
492 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
493 *buffer, subtree_nr);
494#endif
495 /*
497 * Just a heuristic -- we do not add directories that often but
498 * we do not want to have to extend it immediately when we do,
499 * hence +2.
500 */
501 it->subtree_alloc = subtree_nr + 2;
502 it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
503 for (i = 0; i < subtree_nr; i++) {
504 /* read each subtree */
505 struct cache_tree *sub;
506 struct cache_tree_sub *subtree;
507 const char *name = buf;
508 sub = read_one(&buf, &size);
510 if (!sub)
511 goto free_return;
512 subtree = cache_tree_sub(it, name);
513 subtree->cache_tree = sub;
514 }
515 if (subtree_nr != it->subtree_nr)
516 die("cache-tree: internal error");
517 *buffer = buf;
518 *size_p = size;
519 return it;
520 free_return:
522 cache_tree_free(&it);
523 return NULL;
524}
525struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
527{
528 if (buffer[0])
529 return NULL; /* not the whole tree */
530 return read_one(&buffer, &size);
531}
532struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
534{
535 while (*path) {
536 const char *slash;
537 struct cache_tree_sub *sub;
538 slash = strchr(path, '/');
540 if (!slash)
541 slash = path + strlen(path);
542 /* between path and slash is the name of the
543 * subtree to look for.
544 */
545 sub = find_subtree(it, path, slash - path, 0);
546 if (!sub)
547 return NULL;
548 it = sub->cache_tree;
549 if (slash)
550 while (*slash && *slash == '/')
551 slash++;
552 if (!slash || !*slash)
553 return it; /* prefix ended with slashes */
554 path = slash;
555 }
556 return it;
557}