summaryrefslogtreecommitdiff
path: root/cache-tree.c
blob: 50b35264fd0405a299700ef8bf4a61f416f30e46 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
#include "cache.h"
#include "tree.h"
#include "cache-tree.h"
 
#ifndef DEBUG
#define DEBUG 0
#endif
 
struct cache_tree *cache_tree(void)
{
	struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
	it->entry_count = -1;
	return it;
}
 
void cache_tree_free(struct cache_tree **it_p)
{
	int i;
	struct cache_tree *it = *it_p;
 
	if (!it)
		return;
	for (i = 0; i < it->subtree_nr; i++)
		if (it->down[i])
			cache_tree_free(&it->down[i]->cache_tree);
	free(it->down);
	free(it);
	*it_p = NULL;
}
 
static int subtree_name_cmp(const char *one, int onelen,
			    const char *two, int twolen)
{
	if (onelen < twolen)
		return -1;
	if (twolen < onelen)
		return 1;
	return memcmp(one, two, onelen);
}
 
static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
{
	struct cache_tree_sub **down = it->down;
	int lo, hi;
	lo = 0;
	hi = it->subtree_nr;
	while (lo < hi) {
		int mi = (lo + hi) / 2;
		struct cache_tree_sub *mdl = down[mi];
		int cmp = subtree_name_cmp(path, pathlen,
					   mdl->name, mdl->namelen);
		if (!cmp)
			return mi;
		if (cmp < 0)
			hi = mi;
		else
			lo = mi + 1;
	}
	return -lo-1;
}
 
static struct cache_tree_sub *find_subtree(struct cache_tree *it,
					   const char *path,
					   int pathlen,
					   int create)
{
	struct cache_tree_sub *down;
	int pos = subtree_pos(it, path, pathlen);
	if (0 <= pos)
		return it->down[pos];
	if (!create)
		return NULL;
 
	pos = -pos-1;
	if (it->subtree_alloc <= it->subtree_nr) {
		it->subtree_alloc = alloc_nr(it->subtree_alloc);
		it->down = xrealloc(it->down, it->subtree_alloc *
				    sizeof(*it->down));
	}
	it->subtree_nr++;
 
	down = xmalloc(sizeof(*down) + pathlen + 1);
	down->cache_tree = NULL;
	down->namelen = pathlen;
	memcpy(down->name, path, pathlen);
	down->name[pathlen] = 0;
 
	if (pos < it->subtree_nr)
		memmove(it->down + pos + 1,
			it->down + pos,
			sizeof(down) * (it->subtree_nr - pos - 1));
	it->down[pos] = down;
	return down;
}
 
struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
{
	int pathlen = strlen(path);
	return find_subtree(it, path, pathlen, 1);
}
 
void cache_tree_invalidate_path(struct cache_tree *it, const char *path)
{
	/* a/b/c
	 * ==> invalidate self
	 * ==> find "a", have it invalidate "b/c"
	 * a
	 * ==> invalidate self
	 * ==> if "a" exists as a subtree, remove it.
	 */
	const char *slash;
	int namelen;
	struct cache_tree_sub *down;
 
#if DEBUG
	fprintf(stderr, "cache-tree invalidate <%s>\n", path);
#endif
 
	if (!it)
		return;
	slash = strchr(path, '/');
	it->entry_count = -1;
	if (!slash) {
		int pos;
		namelen = strlen(path);
		pos = subtree_pos(it, path, namelen);
		if (0 <= pos) {
			cache_tree_free(&it->down[pos]->cache_tree);
			free(it->down[pos]);
			/* 0 1 2 3 4 5
			 *       ^     ^subtree_nr = 6
			 *       pos
			 * move 4 and 5 up one place (2 entries)
			 * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
			 */
			memmove(it->down+pos, it->down+pos+1,
				sizeof(struct cache_tree_sub *) *
				(it->subtree_nr - pos - 1));
			it->subtree_nr--;
		}
		return;
	}
	namelen = slash - path;
	down = find_subtree(it, path, namelen, 0);
	if (down)
		cache_tree_invalidate_path(down->cache_tree, slash + 1);
}
 
static int verify_cache(struct cache_entry **cache,
			int entries)
{
	int i, funny;
 
	/* Verify that the tree is merged */
	funny = 0;
	for (i = 0; i < entries; i++) {
		struct cache_entry *ce = cache[i];
		if (ce_stage(ce)) {
			if (10 < ++funny) {
				fprintf(stderr, "...\n");
				break;
			}
			fprintf(stderr, "%s: unmerged (%s)\n",
				ce->name, sha1_to_hex(ce->sha1));
		}
	}
	if (funny)
		return -1;
 
	/* Also verify that the cache does not have path and path/file
	 * at the same time.  At this point we know the cache has only
	 * stage 0 entries.
	 */
	funny = 0;
	for (i = 0; i < entries - 1; i++) {
		/* path/file always comes after path because of the way
		 * the cache is sorted.  Also path can appear only once,
		 * which means conflicting one would immediately follow.
		 */
		const char *this_name = cache[i]->name;
		const char *next_name = cache[i+1]->name;
		int this_len = strlen(this_name);
		if (this_len < strlen(next_name) &&
		    strncmp(this_name, next_name, this_len) == 0 &&
		    next_name[this_len] == '/') {
			if (10 < ++funny) {
				fprintf(stderr, "...\n");
				break;
			}
			fprintf(stderr, "You have both %s and %s\n",
				this_name, next_name);
		}
	}
	if (funny)
		return -1;
	return 0;
}
 
static void discard_unused_subtrees(struct cache_tree *it)
{
	struct cache_tree_sub **down = it->down;
	int nr = it->subtree_nr;
	int dst, src;
	for (dst = src = 0; src < nr; src++) {
		struct cache_tree_sub *s = down[src];
		if (s->used)
			down[dst++] = s;
		else {
			cache_tree_free(&s->cache_tree);
			free(s);
			it->subtree_nr--;
		}
	}
}
 
int cache_tree_fully_valid(struct cache_tree *it)
{
	int i;
	if (!it)
		return 0;
	if (it->entry_count < 0 || !has_sha1_file(it->sha1))
		return 0;
	for (i = 0; i < it->subtree_nr; i++) {
		if (!cache_tree_fully_valid(it->down[i]->cache_tree))
			return 0;
	}
	return 1;
}
 
static int update_one(struct cache_tree *it,
		      struct cache_entry **cache,
		      int entries,
		      const char *base,
		      int baselen,
		      int missing_ok,
		      int dryrun)
{
	struct strbuf buffer;
	int i;
 
	if (0 <= it->entry_count && has_sha1_file(it->sha1))
		return it->entry_count;
 
	/*
	 * We first scan for subtrees and update them; we start by
	 * marking existing subtrees -- the ones that are unmarked
	 * should not be in the result.
	 */
	for (i = 0; i < it->subtree_nr; i++)
		it->down[i]->used = 0;
 
	/*
	 * Find the subtrees and update them.
	 */
	for (i = 0; i < entries; i++) {
		struct cache_entry *ce = cache[i];
		struct cache_tree_sub *sub;
		const char *path, *slash;
		int pathlen, sublen, subcnt;
 
		path = ce->name;
		pathlen = ce_namelen(ce);
		if (pathlen <= baselen || memcmp(base, path, baselen))
			break; /* at the end of this level */
 
		slash = strchr(path + baselen, '/');
		if (!slash)
			continue;
		/*
		 * a/bbb/c (base = a/, slash = /c)
		 * ==>
		 * path+baselen = bbb/c, sublen = 3
		 */
		sublen = slash - (path + baselen);
		sub = find_subtree(it, path + baselen, sublen, 1);
		if (!sub->cache_tree)
			sub->cache_tree = cache_tree();
		subcnt = update_one(sub->cache_tree,
				    cache + i, entries - i,
				    path,
				    baselen + sublen + 1,
				    missing_ok,
				    dryrun);
		if (subcnt < 0)
			return subcnt;
		i += subcnt - 1;
		sub->used = 1;
	}
 
	discard_unused_subtrees(it);
 
	/*
	 * Then write out the tree object for this level.
	 */
	strbuf_init(&buffer, 8192);
 
	for (i = 0; i < entries; i++) {
		struct cache_entry *ce = cache[i];
		struct cache_tree_sub *sub;
		const char *path, *slash;
		int pathlen, entlen;
		const unsigned char *sha1;
		unsigned mode;
 
		path = ce->name;
		pathlen = ce_namelen(ce);
		if (pathlen <= baselen || memcmp(base, path, baselen))
			break; /* at the end of this level */
 
		slash = strchr(path + baselen, '/');
		if (slash) {
			entlen = slash - (path + baselen);
			sub = find_subtree(it, path + baselen, entlen, 0);
			if (!sub)
				die("cache-tree.c: '%.*s' in '%s' not found",
				    entlen, path + baselen, path);
			i += sub->cache_tree->entry_count - 1;
			sha1 = sub->cache_tree->sha1;
			mode = S_IFDIR;
		}
		else {
			sha1 = ce->sha1;
			mode = ntohl(ce->ce_mode);
			entlen = pathlen - baselen;
		}
		if (mode != S_IFGITLINK && !missing_ok && !has_sha1_file(sha1))
			return error("invalid object %s", sha1_to_hex(sha1));
 
		if (!ce->ce_mode)
			continue; /* entry being removed */
 
		strbuf_grow(&buffer, entlen + 100);
		strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');
		strbuf_add(&buffer, sha1, 20);
 
#if DEBUG
		fprintf(stderr, "cache-tree update-one %o %.*s\n",
			mode, entlen, path + baselen);
#endif
	}
 
	if (dryrun)
		hash_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
	else
		write_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
	strbuf_release(&buffer);
	it->entry_count = i;
#if DEBUG
	fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
		it->entry_count, it->subtree_nr,
		sha1_to_hex(it->sha1));
#endif
	return i;
}
 
int cache_tree_update(struct cache_tree *it,
		      struct cache_entry **cache,
		      int entries,
		      int missing_ok,
		      int dryrun)
{
	int i;
	i = verify_cache(cache, entries);
	if (i)
		return i;
	i = update_one(it, cache, entries, "", 0, missing_ok, dryrun);
	if (i < 0)
		return i;
	return 0;
}
 
static void write_one(struct strbuf *buffer, struct cache_tree *it,
                      const char *path, int pathlen)
{
	int i;
 
	/* One "cache-tree" entry consists of the following:
	 * path (NUL terminated)
	 * entry_count, subtree_nr ("%d %d\n")
	 * tree-sha1 (missing if invalid)
	 * subtree_nr "cache-tree" entries for subtrees.
	 */
	strbuf_grow(buffer, pathlen + 100);
	strbuf_add(buffer, path, pathlen);
	strbuf_addf(buffer, "%c%d %d\n", 0, it->entry_count, it->subtree_nr);
 
#if DEBUG
	if (0 <= it->entry_count)
		fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
			pathlen, path, it->entry_count, it->subtree_nr,
			sha1_to_hex(it->sha1));
	else
		fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
			pathlen, path, it->subtree_nr);
#endif
 
	if (0 <= it->entry_count) {
		strbuf_add(buffer, it->sha1, 20);
	}
	for (i = 0; i < it->subtree_nr; i++) {
		struct cache_tree_sub *down = it->down[i];
		if (i) {
			struct cache_tree_sub *prev = it->down[i-1];
			if (subtree_name_cmp(down->name, down->namelen,
					     prev->name, prev->namelen) <= 0)
				die("fatal - unsorted cache subtree");
		}
		write_one(buffer, down->cache_tree, down->name, down->namelen);
	}
}
 
void cache_tree_write(struct strbuf *sb, struct cache_tree *root)
{
	write_one(sb, root, "", 0);
}
 
static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
{
	const char *buf = *buffer;
	unsigned long size = *size_p;
	const char *cp;
	char *ep;
	struct cache_tree *it;
	int i, subtree_nr;
 
	it = NULL;
	/* skip name, but make sure name exists */
	while (size && *buf) {
		size--;
		buf++;
	}
	if (!size)
		goto free_return;
	buf++; size--;
	it = cache_tree();
 
	cp = buf;
	it->entry_count = strtol(cp, &ep, 10);
	if (cp == ep)
		goto free_return;
	cp = ep;
	subtree_nr = strtol(cp, &ep, 10);
	if (cp == ep)
		goto free_return;
	while (size && *buf && *buf != '\n') {
		size--;
		buf++;
	}
	if (!size)
		goto free_return;
	buf++; size--;
	if (0 <= it->entry_count) {
		if (size < 20)
			goto free_return;
		hashcpy(it->sha1, (const unsigned char*)buf);
		buf += 20;
		size -= 20;
	}
 
#if DEBUG
	if (0 <= it->entry_count)
		fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
			*buffer, it->entry_count, subtree_nr,
			sha1_to_hex(it->sha1));
	else
		fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
			*buffer, subtree_nr);
#endif
 
	/*
	 * Just a heuristic -- we do not add directories that often but
	 * we do not want to have to extend it immediately when we do,
	 * hence +2.
	 */
	it->subtree_alloc = subtree_nr + 2;
	it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
	for (i = 0; i < subtree_nr; i++) {
		/* read each subtree */
		struct cache_tree *sub;
		struct cache_tree_sub *subtree;
		const char *name = buf;
 
		sub = read_one(&buf, &size);
		if (!sub)
			goto free_return;
		subtree = cache_tree_sub(it, name);
		subtree->cache_tree = sub;
	}
	if (subtree_nr != it->subtree_nr)
		die("cache-tree: internal error");
	*buffer = buf;
	*size_p = size;
	return it;
 
 free_return:
	cache_tree_free(&it);
	return NULL;
}
 
struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
{
	if (buffer[0])
		return NULL; /* not the whole tree */
	return read_one(&buffer, &size);
}
 
struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
{
	while (*path) {
		const char *slash;
		struct cache_tree_sub *sub;
 
		slash = strchr(path, '/');
		if (!slash)
			slash = path + strlen(path);
		/* between path and slash is the name of the
		 * subtree to look for.
		 */
		sub = find_subtree(it, path, slash - path, 0);
		if (!sub)
			return NULL;
		it = sub->cache_tree;
		if (slash)
			while (*slash && *slash == '/')
				slash++;
		if (!slash || !*slash)
			return it; /* prefix ended with slashes */
		path = slash;
	}
	return it;
}