read-tree: invalidate cache-tree entry when a new index entry is added.
[git/git.git] / cache-tree.c
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1#include "cache.h"
2#include "tree.h"
3#include "cache-tree.h"
4
5#define DEBUG 0
6
7struct 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}
13
bad68ec9 14void cache_tree_free(struct cache_tree **it_p)
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15{
16 int i;
bad68ec9 17 struct cache_tree *it = *it_p;
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18
19 if (!it)
20 return;
21 for (i = 0; i < it->subtree_nr; i++)
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22 if (it->down[i])
23 cache_tree_free(&it->down[i]->cache_tree);
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24 free(it->down);
25 free(it);
bad68ec9 26 *it_p = NULL;
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27}
28
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29static 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}
38
39static 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}
59
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60static struct cache_tree_sub *find_subtree(struct cache_tree *it,
61 const char *path,
62 int pathlen,
63 int create)
64{
74986462 65 struct cache_tree_sub *down;
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66 int pos = subtree_pos(it, path, pathlen);
67 if (0 <= pos)
68 return it->down[pos];
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69 if (!create)
70 return NULL;
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71
72 pos = -pos-1;
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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 }
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78 it->subtree_nr++;
79
74986462 80 down = xmalloc(sizeof(*down) + pathlen + 1);
61fa3097 81 down->cache_tree = NULL;
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82 down->namelen = pathlen;
83 memcpy(down->name, path, pathlen);
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84 down->name[pathlen] = 0;
85
86 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;
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91 return down;
92}
93
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94struct 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}
99
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100void 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
113 if (!it)
114 return;
115 slash = strchr(path, '/');
116 it->entry_count = -1;
117 if (!slash) {
61fa3097 118 int pos;
74986462 119 namelen = strlen(path);
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120 pos = subtree_pos(it, path, namelen);
121 if (0 <= pos) {
122 cache_tree_free(&it->down[pos]->cache_tree);
123 free(it->down[pos]);
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124 /* 0 1 2 3 4 5
125 * ^ ^subtree_nr = 6
61fa3097 126 * pos
74986462 127 * move 4 and 5 up one place (2 entries)
61fa3097 128 * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
74986462 129 */
61fa3097 130 memmove(it->down+pos, it->down+pos+1,
74986462 131 sizeof(struct cache_tree_sub *) *
61fa3097 132 (it->subtree_nr - pos - 1));
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133 it->subtree_nr--;
134 }
135 return;
136 }
137 namelen = slash - path;
138 down = find_subtree(it, path, namelen, 0);
139 if (down)
140 cache_tree_invalidate_path(down->cache_tree, slash + 1);
141}
142
143static int verify_cache(struct cache_entry **cache,
144 int entries)
145{
146 int i, funny;
147
148 /* Verify that the tree is merged */
149 funny = 0;
150 for (i = 0; i < entries; i++) {
151 struct cache_entry *ce = cache[i];
152 if (ce_stage(ce)) {
153 if (10 < ++funny) {
154 fprintf(stderr, "...\n");
155 break;
156 }
157 fprintf(stderr, "%s: unmerged (%s)\n",
158 ce->name, sha1_to_hex(ce->sha1));
159 }
160 }
161 if (funny)
162 return -1;
163
164 /* Also verify that the cache does not have path and path/file
165 * at the same time. At this point we know the cache has only
166 * stage 0 entries.
167 */
168 funny = 0;
169 for (i = 0; i < entries - 1; i++) {
170 /* path/file always comes after path because of the way
171 * the cache is sorted. Also path can appear only once,
172 * which means conflicting one would immediately follow.
173 */
174 const char *this_name = cache[i]->name;
175 const char *next_name = cache[i+1]->name;
176 int this_len = strlen(this_name);
177 if (this_len < strlen(next_name) &&
178 strncmp(this_name, next_name, this_len) == 0 &&
179 next_name[this_len] == '/') {
180 if (10 < ++funny) {
181 fprintf(stderr, "...\n");
182 break;
183 }
184 fprintf(stderr, "You have both %s and %s\n",
185 this_name, next_name);
186 }
187 }
188 if (funny)
189 return -1;
190 return 0;
191}
192
193static void discard_unused_subtrees(struct cache_tree *it)
194{
195 struct cache_tree_sub **down = it->down;
196 int nr = it->subtree_nr;
197 int dst, src;
198 for (dst = src = 0; src < nr; src++) {
199 struct cache_tree_sub *s = down[src];
200 if (s->used)
201 down[dst++] = s;
202 else {
bad68ec9 203 cache_tree_free(&s->cache_tree);
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204 free(s);
205 it->subtree_nr--;
206 }
207 }
208}
209
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210int cache_tree_fully_valid(struct cache_tree *it)
211{
212 int i;
213 if (!it)
214 return 0;
215 if (it->entry_count < 0 || !has_sha1_file(it->sha1))
216 return 0;
217 for (i = 0; i < it->subtree_nr; i++) {
218 if (!cache_tree_fully_valid(it->down[i]->cache_tree))
219 return 0;
220 }
221 return 1;
222}
223
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224static int update_one(struct cache_tree *it,
225 struct cache_entry **cache,
226 int entries,
227 const char *base,
228 int baselen,
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229 int missing_ok,
230 int dryrun)
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231{
232 unsigned long size, offset;
233 char *buffer;
234 int i;
235
dd0c34c4 236 if (0 <= it->entry_count && has_sha1_file(it->sha1))
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237 return it->entry_count;
238
239 /*
240 * We first scan for subtrees and update them; we start by
241 * marking existing subtrees -- the ones that are unmarked
242 * should not be in the result.
243 */
244 for (i = 0; i < it->subtree_nr; i++)
245 it->down[i]->used = 0;
246
247 /*
248 * Find the subtrees and update them.
249 */
250 for (i = 0; i < entries; i++) {
251 struct cache_entry *ce = cache[i];
252 struct cache_tree_sub *sub;
253 const char *path, *slash;
254 int pathlen, sublen, subcnt;
255
256 path = ce->name;
257 pathlen = ce_namelen(ce);
258 if (pathlen <= baselen || memcmp(base, path, baselen))
259 break; /* at the end of this level */
260
261 slash = strchr(path + baselen, '/');
262 if (!slash)
263 continue;
264 /*
265 * a/bbb/c (base = a/, slash = /c)
266 * ==>
267 * path+baselen = bbb/c, sublen = 3
268 */
269 sublen = slash - (path + baselen);
270 sub = find_subtree(it, path + baselen, sublen, 1);
271 if (!sub->cache_tree)
272 sub->cache_tree = cache_tree();
273 subcnt = update_one(sub->cache_tree,
274 cache + i, entries - i,
275 path,
276 baselen + sublen + 1,
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277 missing_ok,
278 dryrun);
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279 i += subcnt - 1;
280 sub->used = 1;
281 }
282
283 discard_unused_subtrees(it);
284
285 /*
286 * Then write out the tree object for this level.
287 */
288 size = 8192;
289 buffer = xmalloc(size);
290 offset = 0;
291
292 for (i = 0; i < entries; i++) {
293 struct cache_entry *ce = cache[i];
294 struct cache_tree_sub *sub;
295 const char *path, *slash;
296 int pathlen, entlen;
297 const unsigned char *sha1;
298 unsigned mode;
299
300 path = ce->name;
301 pathlen = ce_namelen(ce);
302 if (pathlen <= baselen || memcmp(base, path, baselen))
303 break; /* at the end of this level */
304
305 slash = strchr(path + baselen, '/');
306 if (slash) {
307 entlen = slash - (path + baselen);
308 sub = find_subtree(it, path + baselen, entlen, 0);
309 if (!sub)
310 die("cache-tree.c: '%.*s' in '%s' not found",
311 entlen, path + baselen, path);
312 i += sub->cache_tree->entry_count - 1;
313 sha1 = sub->cache_tree->sha1;
314 mode = S_IFDIR;
315 }
316 else {
317 sha1 = ce->sha1;
318 mode = ntohl(ce->ce_mode);
319 entlen = pathlen - baselen;
320 }
321 if (!missing_ok && !has_sha1_file(sha1))
322 return error("invalid object %s", sha1_to_hex(sha1));
323
324 if (!ce->ce_mode)
325 continue; /* entry being removed */
326
327 if (size < offset + entlen + 100) {
328 size = alloc_nr(offset + entlen + 100);
329 buffer = xrealloc(buffer, size);
330 }
331 offset += sprintf(buffer + offset,
332 "%o %.*s", mode, entlen, path + baselen);
333 buffer[offset++] = 0;
334 memcpy(buffer + offset, sha1, 20);
335 offset += 20;
336
337#if DEBUG
338 fprintf(stderr, "cache-tree %o %.*s\n",
339 mode, entlen, path + baselen);
340#endif
341 }
342
2956dd3b 343 if (dryrun) {
7bc70a59 344 unsigned char hdr[200];
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345 int hdrlen;
346 write_sha1_file_prepare(buffer, offset, tree_type, it->sha1,
347 hdr, &hdrlen);
348 }
349 else
350 write_sha1_file(buffer, offset, tree_type, it->sha1);
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351 free(buffer);
352 it->entry_count = i;
353#if DEBUG
354 fprintf(stderr, "cache-tree (%d ent, %d subtree) %s\n",
355 it->entry_count, it->subtree_nr,
356 sha1_to_hex(it->sha1));
357#endif
358 return i;
359}
360
361int cache_tree_update(struct cache_tree *it,
362 struct cache_entry **cache,
363 int entries,
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364 int missing_ok,
365 int dryrun)
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366{
367 int i;
368 i = verify_cache(cache, entries);
369 if (i)
370 return i;
2956dd3b 371 i = update_one(it, cache, entries, "", 0, missing_ok, dryrun);
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372 if (i < 0)
373 return i;
374 return 0;
375}
376
377static void *write_one(struct cache_tree *it,
378 char *path,
379 int pathlen,
380 char *buffer,
381 unsigned long *size,
382 unsigned long *offset)
383{
384 int i;
385
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.
391 */
392 if (*size < *offset + pathlen + 100) {
393 *size = alloc_nr(*offset + pathlen + 100);
394 buffer = xrealloc(buffer, *size);
395 }
396 *offset += sprintf(buffer + *offset, "%.*s%c%d %d\n",
397 pathlen, path, 0,
398 it->entry_count, it->subtree_nr);
399
400#if DEBUG
401 if (0 <= it->entry_count)
402 fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
403 pathlen, path, it->entry_count, it->subtree_nr,
404 sha1_to_hex(it->sha1));
405 else
406 fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
407 pathlen, path, it->subtree_nr);
408#endif
409
410 if (0 <= it->entry_count) {
411 memcpy(buffer + *offset, it->sha1, 20);
412 *offset += 20;
413 }
414 for (i = 0; i < it->subtree_nr; i++) {
415 struct cache_tree_sub *down = it->down[i];
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416 if (i) {
417 struct cache_tree_sub *prev = it->down[i-1];
418 if (subtree_name_cmp(down->name, down->namelen,
419 prev->name, prev->namelen) <= 0)
420 die("fatal - unsorted cache subtree");
421 }
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422 buffer = write_one(down->cache_tree, down->name, down->namelen,
423 buffer, size, offset);
424 }
425 return buffer;
426}
427
bad68ec9 428void *cache_tree_write(struct cache_tree *root, unsigned long *size_p)
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429{
430 char path[PATH_MAX];
431 unsigned long size = 8192;
432 char *buffer = xmalloc(size);
433
bad68ec9 434 *size_p = 0;
74986462 435 path[0] = 0;
bad68ec9 436 return write_one(root, path, 0, buffer, &size, size_p);
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437}
438
439static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
440{
441 const char *buf = *buffer;
442 unsigned long size = *size_p;
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443 const char *cp;
444 char *ep;
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445 struct cache_tree *it;
446 int i, subtree_nr;
447
448 it = NULL;
449 /* skip name, but make sure name exists */
450 while (size && *buf) {
451 size--;
452 buf++;
453 }
454 if (!size)
455 goto free_return;
456 buf++; size--;
457 it = cache_tree();
0111ea38
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458
459 cp = buf;
460 it->entry_count = strtol(cp, &ep, 10);
461 if (cp == ep)
462 goto free_return;
463 cp = ep;
464 subtree_nr = strtol(cp, &ep, 10);
465 if (cp == ep)
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466 goto free_return;
467 while (size && *buf && *buf != '\n') {
468 size--;
469 buf++;
470 }
471 if (!size)
472 goto free_return;
473 buf++; size--;
474 if (0 <= it->entry_count) {
475 if (size < 20)
476 goto free_return;
477 memcpy(it->sha1, buf, 20);
478 buf += 20;
479 size -= 20;
480 }
481
482#if DEBUG
483 if (0 <= it->entry_count)
484 fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
485 *buffer, it->entry_count, subtree_nr,
486 sha1_to_hex(it->sha1));
487 else
488 fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
489 *buffer, subtree_nr);
490#endif
491
492 /*
493 * Just a heuristic -- we do not add directories that often but
494 * we do not want to have to extend it immediately when we do,
495 * hence +2.
496 */
497 it->subtree_alloc = subtree_nr + 2;
498 it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
499 for (i = 0; i < subtree_nr; i++) {
500 /* read each subtree */
501 struct cache_tree *sub;
61fa3097 502 struct cache_tree_sub *subtree;
74986462 503 const char *name = buf;
7927a55d 504
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505 sub = read_one(&buf, &size);
506 if (!sub)
507 goto free_return;
7927a55d 508 subtree = cache_tree_sub(it, name);
61fa3097 509 subtree->cache_tree = sub;
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510 }
511 if (subtree_nr != it->subtree_nr)
512 die("cache-tree: internal error");
513 *buffer = buf;
514 *size_p = size;
515 return it;
516
517 free_return:
bad68ec9 518 cache_tree_free(&it);
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519 return NULL;
520}
521
bad68ec9 522struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
74986462 523{
bad68ec9 524 if (buffer[0])
74986462 525 return NULL; /* not the whole tree */
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526 return read_one(&buffer, &size);
527}