Merge branch 'pw/p4'
[git/mjg.git] / tree-walk.c
blob322becc3b4ad50b8e87fae8f6d5d38f7edc51f01
1 #include "cache.h"
2 #include "tree-walk.h"
3 #include "unpack-trees.h"
4 #include "dir.h"
5 #include "tree.h"
7 static const char *get_mode(const char *str, unsigned int *modep)
9 unsigned char c;
10 unsigned int mode = 0;
12 if (*str == ' ')
13 return NULL;
15 while ((c = *str++) != ' ') {
16 if (c < '0' || c > '7')
17 return NULL;
18 mode = (mode << 3) + (c - '0');
20 *modep = mode;
21 return str;
24 static void decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned long size)
26 const char *path;
27 unsigned int mode, len;
29 if (size < 24 || buf[size - 21])
30 die("corrupt tree file");
32 path = get_mode(buf, &mode);
33 if (!path || !*path)
34 die("corrupt tree file");
35 len = strlen(path) + 1;
37 /* Initialize the descriptor entry */
38 desc->entry.path = path;
39 desc->entry.mode = mode;
40 desc->entry.sha1 = (const unsigned char *)(path + len);
43 void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
45 desc->buffer = buffer;
46 desc->size = size;
47 if (size)
48 decode_tree_entry(desc, buffer, size);
51 void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1)
53 unsigned long size = 0;
54 void *buf = NULL;
56 if (sha1) {
57 buf = read_object_with_reference(sha1, tree_type, &size, NULL);
58 if (!buf)
59 die("unable to read tree %s", sha1_to_hex(sha1));
61 init_tree_desc(desc, buf, size);
62 return buf;
65 static void entry_clear(struct name_entry *a)
67 memset(a, 0, sizeof(*a));
70 static void entry_extract(struct tree_desc *t, struct name_entry *a)
72 *a = t->entry;
75 void update_tree_entry(struct tree_desc *desc)
77 const void *buf = desc->buffer;
78 const unsigned char *end = desc->entry.sha1 + 20;
79 unsigned long size = desc->size;
80 unsigned long len = end - (const unsigned char *)buf;
82 if (size < len)
83 die("corrupt tree file");
84 buf = end;
85 size -= len;
86 desc->buffer = buf;
87 desc->size = size;
88 if (size)
89 decode_tree_entry(desc, buf, size);
92 int tree_entry(struct tree_desc *desc, struct name_entry *entry)
94 if (!desc->size)
95 return 0;
97 *entry = desc->entry;
98 update_tree_entry(desc);
99 return 1;
102 void setup_traverse_info(struct traverse_info *info, const char *base)
104 int pathlen = strlen(base);
105 static struct traverse_info dummy;
107 memset(info, 0, sizeof(*info));
108 if (pathlen && base[pathlen-1] == '/')
109 pathlen--;
110 info->pathlen = pathlen ? pathlen + 1 : 0;
111 info->name.path = base;
112 info->name.sha1 = (void *)(base + pathlen + 1);
113 if (pathlen)
114 info->prev = &dummy;
117 char *make_traverse_path(char *path, const struct traverse_info *info, const struct name_entry *n)
119 int len = tree_entry_len(n->path, n->sha1);
120 int pathlen = info->pathlen;
122 path[pathlen + len] = 0;
123 for (;;) {
124 memcpy(path + pathlen, n->path, len);
125 if (!pathlen)
126 break;
127 path[--pathlen] = '/';
128 n = &info->name;
129 len = tree_entry_len(n->path, n->sha1);
130 info = info->prev;
131 pathlen -= len;
133 return path;
136 struct tree_desc_skip {
137 struct tree_desc_skip *prev;
138 const void *ptr;
141 struct tree_desc_x {
142 struct tree_desc d;
143 struct tree_desc_skip *skip;
146 static int name_compare(const char *a, int a_len,
147 const char *b, int b_len)
149 int len = (a_len < b_len) ? a_len : b_len;
150 int cmp = memcmp(a, b, len);
151 if (cmp)
152 return cmp;
153 return (a_len - b_len);
156 static int check_entry_match(const char *a, int a_len, const char *b, int b_len)
159 * The caller wants to pick *a* from a tree or nothing.
160 * We are looking at *b* in a tree.
162 * (0) If a and b are the same name, we are trivially happy.
164 * There are three possibilities where *a* could be hiding
165 * behind *b*.
167 * (1) *a* == "t", *b* == "ab" i.e. *b* sorts earlier than *a* no
168 * matter what.
169 * (2) *a* == "t", *b* == "t-2" and "t" is a subtree in the tree;
170 * (3) *a* == "t-2", *b* == "t" and "t-2" is a blob in the tree.
172 * Otherwise we know *a* won't appear in the tree without
173 * scanning further.
176 int cmp = name_compare(a, a_len, b, b_len);
178 /* Most common case first -- reading sync'd trees */
179 if (!cmp)
180 return cmp;
182 if (0 < cmp) {
183 /* a comes after b; it does not matter if it is case (3)
184 if (b_len < a_len && !memcmp(a, b, b_len) && a[b_len] < '/')
185 return 1;
187 return 1; /* keep looking */
190 /* b comes after a; are we looking at case (2)? */
191 if (a_len < b_len && !memcmp(a, b, a_len) && b[a_len] < '/')
192 return 1; /* keep looking */
194 return -1; /* a cannot appear in the tree */
198 * From the extended tree_desc, extract the first name entry, while
199 * paying attention to the candidate "first" name. Most importantly,
200 * when looking for an entry, if there are entries that sorts earlier
201 * in the tree object representation than that name, skip them and
202 * process the named entry first. We will remember that we haven't
203 * processed the first entry yet, and in the later call skip the
204 * entry we processed early when update_extended_entry() is called.
206 * E.g. if the underlying tree object has these entries:
208 * blob "t-1"
209 * blob "t-2"
210 * tree "t"
211 * blob "t=1"
213 * and the "first" asks for "t", remember that we still need to
214 * process "t-1" and "t-2" but extract "t". After processing the
215 * entry "t" from this call, the caller will let us know by calling
216 * update_extended_entry() that we can remember "t" has been processed
217 * already.
220 static void extended_entry_extract(struct tree_desc_x *t,
221 struct name_entry *a,
222 const char *first,
223 int first_len)
225 const char *path;
226 int len;
227 struct tree_desc probe;
228 struct tree_desc_skip *skip;
231 * Extract the first entry from the tree_desc, but skip the
232 * ones that we already returned in earlier rounds.
234 while (1) {
235 if (!t->d.size) {
236 entry_clear(a);
237 break; /* not found */
239 entry_extract(&t->d, a);
240 for (skip = t->skip; skip; skip = skip->prev)
241 if (a->path == skip->ptr)
242 break; /* found */
243 if (!skip)
244 break;
245 /* We have processed this entry already. */
246 update_tree_entry(&t->d);
249 if (!first || !a->path)
250 return;
253 * The caller wants "first" from this tree, or nothing.
255 path = a->path;
256 len = tree_entry_len(a->path, a->sha1);
257 switch (check_entry_match(first, first_len, path, len)) {
258 case -1:
259 entry_clear(a);
260 case 0:
261 return;
262 default:
263 break;
267 * We need to look-ahead -- we suspect that a subtree whose
268 * name is "first" may be hiding behind the current entry "path".
270 probe = t->d;
271 while (probe.size) {
272 entry_extract(&probe, a);
273 path = a->path;
274 len = tree_entry_len(a->path, a->sha1);
275 switch (check_entry_match(first, first_len, path, len)) {
276 case -1:
277 entry_clear(a);
278 case 0:
279 return;
280 default:
281 update_tree_entry(&probe);
282 break;
284 /* keep looking */
286 entry_clear(a);
289 static void update_extended_entry(struct tree_desc_x *t, struct name_entry *a)
291 if (t->d.entry.path == a->path) {
292 update_tree_entry(&t->d);
293 } else {
294 /* we have returned this entry early */
295 struct tree_desc_skip *skip = xmalloc(sizeof(*skip));
296 skip->ptr = a->path;
297 skip->prev = t->skip;
298 t->skip = skip;
302 static void free_extended_entry(struct tree_desc_x *t)
304 struct tree_desc_skip *p, *s;
306 for (s = t->skip; s; s = p) {
307 p = s->prev;
308 free(s);
312 int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
314 int ret = 0;
315 int error = 0;
316 struct name_entry *entry = xmalloc(n*sizeof(*entry));
317 int i;
318 struct tree_desc_x *tx = xcalloc(n, sizeof(*tx));
320 for (i = 0; i < n; i++)
321 tx[i].d = t[i];
323 for (;;) {
324 unsigned long mask, dirmask;
325 const char *first = NULL;
326 int first_len = 0;
327 struct name_entry *e;
328 int len;
330 for (i = 0; i < n; i++) {
331 e = entry + i;
332 extended_entry_extract(tx + i, e, NULL, 0);
336 * A tree may have "t-2" at the current location even
337 * though it may have "t" that is a subtree behind it,
338 * and another tree may return "t". We want to grab
339 * all "t" from all trees to match in such a case.
341 for (i = 0; i < n; i++) {
342 e = entry + i;
343 if (!e->path)
344 continue;
345 len = tree_entry_len(e->path, e->sha1);
346 if (!first) {
347 first = e->path;
348 first_len = len;
349 continue;
351 if (name_compare(e->path, len, first, first_len) < 0) {
352 first = e->path;
353 first_len = len;
357 if (first) {
358 for (i = 0; i < n; i++) {
359 e = entry + i;
360 extended_entry_extract(tx + i, e, first, first_len);
361 /* Cull the ones that are not the earliest */
362 if (!e->path)
363 continue;
364 len = tree_entry_len(e->path, e->sha1);
365 if (name_compare(e->path, len, first, first_len))
366 entry_clear(e);
370 /* Now we have in entry[i] the earliest name from the trees */
371 mask = 0;
372 dirmask = 0;
373 for (i = 0; i < n; i++) {
374 if (!entry[i].path)
375 continue;
376 mask |= 1ul << i;
377 if (S_ISDIR(entry[i].mode))
378 dirmask |= 1ul << i;
380 if (!mask)
381 break;
382 ret = info->fn(n, mask, dirmask, entry, info);
383 if (ret < 0) {
384 error = ret;
385 if (!info->show_all_errors)
386 break;
388 mask &= ret;
389 ret = 0;
390 for (i = 0; i < n; i++)
391 if (mask & (1ul << i))
392 update_extended_entry(tx + i, entry + i);
394 free(entry);
395 for (i = 0; i < n; i++)
396 free_extended_entry(tx + i);
397 free(tx);
398 return error;
401 static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char *result, unsigned *mode)
403 int namelen = strlen(name);
404 while (t->size) {
405 const char *entry;
406 const unsigned char *sha1;
407 int entrylen, cmp;
409 sha1 = tree_entry_extract(t, &entry, mode);
410 update_tree_entry(t);
411 entrylen = tree_entry_len(entry, sha1);
412 if (entrylen > namelen)
413 continue;
414 cmp = memcmp(name, entry, entrylen);
415 if (cmp > 0)
416 continue;
417 if (cmp < 0)
418 break;
419 if (entrylen == namelen) {
420 hashcpy(result, sha1);
421 return 0;
423 if (name[entrylen] != '/')
424 continue;
425 if (!S_ISDIR(*mode))
426 break;
427 if (++entrylen == namelen) {
428 hashcpy(result, sha1);
429 return 0;
431 return get_tree_entry(sha1, name + entrylen, result, mode);
433 return -1;
436 int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned char *sha1, unsigned *mode)
438 int retval;
439 void *tree;
440 unsigned long size;
441 struct tree_desc t;
442 unsigned char root[20];
444 tree = read_object_with_reference(tree_sha1, tree_type, &size, root);
445 if (!tree)
446 return -1;
448 if (name[0] == '\0') {
449 hashcpy(sha1, root);
450 free(tree);
451 return 0;
454 init_tree_desc(&t, tree, size);
455 retval = find_tree_entry(&t, name, sha1, mode);
456 free(tree);
457 return retval;
460 static int match_entry(const struct name_entry *entry, int pathlen,
461 const char *match, int matchlen,
462 int *never_interesting)
464 int m = -1; /* signals that we haven't called strncmp() */
466 if (*never_interesting) {
468 * We have not seen any match that sorts later
469 * than the current path.
473 * Does match sort strictly earlier than path
474 * with their common parts?
476 m = strncmp(match, entry->path,
477 (matchlen < pathlen) ? matchlen : pathlen);
478 if (m < 0)
479 return 0;
482 * If we come here even once, that means there is at
483 * least one pathspec that would sort equal to or
484 * later than the path we are currently looking at.
485 * In other words, if we have never reached this point
486 * after iterating all pathspecs, it means all
487 * pathspecs are either outside of base, or inside the
488 * base but sorts strictly earlier than the current
489 * one. In either case, they will never match the
490 * subsequent entries. In such a case, we initialized
491 * the variable to -1 and that is what will be
492 * returned, allowing the caller to terminate early.
494 *never_interesting = 0;
497 if (pathlen > matchlen)
498 return 0;
500 if (matchlen > pathlen) {
501 if (match[pathlen] != '/')
502 return 0;
503 if (!S_ISDIR(entry->mode))
504 return 0;
507 if (m == -1)
509 * we cheated and did not do strncmp(), so we do
510 * that here.
512 m = strncmp(match, entry->path, pathlen);
515 * If common part matched earlier then it is a hit,
516 * because we rejected the case where path is not a
517 * leading directory and is shorter than match.
519 if (!m)
520 return 1;
522 return 0;
525 static int match_dir_prefix(const char *base, int baselen,
526 const char *match, int matchlen)
528 if (strncmp(base, match, matchlen))
529 return 0;
532 * If the base is a subdirectory of a path which
533 * was specified, all of them are interesting.
535 if (!matchlen ||
536 base[matchlen] == '/' ||
537 match[matchlen - 1] == '/')
538 return 1;
540 /* Just a random prefix match */
541 return 0;
545 * Is a tree entry interesting given the pathspec we have?
547 * Pre-condition: either baselen == base_offset (i.e. empty path)
548 * or base[baselen-1] == '/' (i.e. with trailing slash).
550 * Return:
551 * - 2 for "yes, and all subsequent entries will be"
552 * - 1 for yes
553 * - zero for no
554 * - negative for "no, and no subsequent entries will be either"
556 int tree_entry_interesting(const struct name_entry *entry,
557 struct strbuf *base, int base_offset,
558 const struct pathspec *ps)
560 int i;
561 int pathlen, baselen = base->len - base_offset;
562 int never_interesting = ps->has_wildcard ? 0 : -1;
564 if (!ps->nr) {
565 if (!ps->recursive || ps->max_depth == -1)
566 return 2;
567 return !!within_depth(base->buf + base_offset, baselen,
568 !!S_ISDIR(entry->mode),
569 ps->max_depth);
572 pathlen = tree_entry_len(entry->path, entry->sha1);
574 for (i = ps->nr - 1; i >= 0; i--) {
575 const struct pathspec_item *item = ps->items+i;
576 const char *match = item->match;
577 const char *base_str = base->buf + base_offset;
578 int matchlen = item->len;
580 if (baselen >= matchlen) {
581 /* If it doesn't match, move along... */
582 if (!match_dir_prefix(base_str, baselen, match, matchlen))
583 goto match_wildcards;
585 if (!ps->recursive || ps->max_depth == -1)
586 return 2;
588 return !!within_depth(base_str + matchlen + 1,
589 baselen - matchlen - 1,
590 !!S_ISDIR(entry->mode),
591 ps->max_depth);
594 /* Does the base match? */
595 if (!strncmp(base_str, match, baselen)) {
596 if (match_entry(entry, pathlen,
597 match + baselen, matchlen - baselen,
598 &never_interesting))
599 return 1;
601 if (ps->items[i].has_wildcard) {
602 if (!fnmatch(match + baselen, entry->path, 0))
603 return 1;
606 * Match all directories. We'll try to
607 * match files later on.
609 if (ps->recursive && S_ISDIR(entry->mode))
610 return 1;
613 continue;
616 match_wildcards:
617 if (!ps->items[i].has_wildcard)
618 continue;
621 * Concatenate base and entry->path into one and do
622 * fnmatch() on it.
625 strbuf_add(base, entry->path, pathlen);
627 if (!fnmatch(match, base->buf + base_offset, 0)) {
628 strbuf_setlen(base, base_offset + baselen);
629 return 1;
631 strbuf_setlen(base, base_offset + baselen);
634 * Match all directories. We'll try to match files
635 * later on.
637 if (ps->recursive && S_ISDIR(entry->mode))
638 return 1;
640 return never_interesting; /* No matches */