Merge branch 'jk/tag-sort'
[git.git] / tree-walk.c
blob5dd9a718047bc14e9ae840a46d1f71cb435fd6d7
1 #include "cache.h"
2 #include "tree-walk.h"
3 #include "unpack-trees.h"
4 #include "dir.h"
5 #include "tree.h"
6 #include "pathspec.h"
8 static const char *get_mode(const char *str, unsigned int *modep)
10 unsigned char c;
11 unsigned int mode = 0;
13 if (*str == ' ')
14 return NULL;
16 while ((c = *str++) != ' ') {
17 if (c < '0' || c > '7')
18 return NULL;
19 mode = (mode << 3) + (c - '0');
21 *modep = mode;
22 return str;
25 static void decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned long size)
27 const char *path;
28 unsigned int mode, len;
30 if (size < 24 || buf[size - 21])
31 die("corrupt tree file");
33 path = get_mode(buf, &mode);
34 if (!path || !*path)
35 die("corrupt tree file");
36 len = strlen(path) + 1;
38 /* Initialize the descriptor entry */
39 desc->entry.path = path;
40 desc->entry.mode = canon_mode(mode);
41 desc->entry.sha1 = (const unsigned char *)(path + len);
44 void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
46 desc->buffer = buffer;
47 desc->size = size;
48 if (size)
49 decode_tree_entry(desc, buffer, size);
52 void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1)
54 unsigned long size = 0;
55 void *buf = NULL;
57 if (sha1) {
58 buf = read_object_with_reference(sha1, tree_type, &size, NULL);
59 if (!buf)
60 die("unable to read tree %s", sha1_to_hex(sha1));
62 init_tree_desc(desc, buf, size);
63 return buf;
66 static void entry_clear(struct name_entry *a)
68 memset(a, 0, sizeof(*a));
71 static void entry_extract(struct tree_desc *t, struct name_entry *a)
73 *a = t->entry;
76 void update_tree_entry(struct tree_desc *desc)
78 const void *buf = desc->buffer;
79 const unsigned char *end = desc->entry.sha1 + 20;
80 unsigned long size = desc->size;
81 unsigned long len = end - (const unsigned char *)buf;
83 if (size < len)
84 die("corrupt tree file");
85 buf = end;
86 size -= len;
87 desc->buffer = buf;
88 desc->size = size;
89 if (size)
90 decode_tree_entry(desc, buf, size);
93 int tree_entry(struct tree_desc *desc, struct name_entry *entry)
95 if (!desc->size)
96 return 0;
98 *entry = desc->entry;
99 update_tree_entry(desc);
100 return 1;
103 void setup_traverse_info(struct traverse_info *info, const char *base)
105 int pathlen = strlen(base);
106 static struct traverse_info dummy;
108 memset(info, 0, sizeof(*info));
109 if (pathlen && base[pathlen-1] == '/')
110 pathlen--;
111 info->pathlen = pathlen ? pathlen + 1 : 0;
112 info->name.path = base;
113 info->name.sha1 = (void *)(base + pathlen + 1);
114 if (pathlen)
115 info->prev = &dummy;
118 char *make_traverse_path(char *path, const struct traverse_info *info, const struct name_entry *n)
120 int len = tree_entry_len(n);
121 int pathlen = info->pathlen;
123 path[pathlen + len] = 0;
124 for (;;) {
125 memcpy(path + pathlen, n->path, len);
126 if (!pathlen)
127 break;
128 path[--pathlen] = '/';
129 n = &info->name;
130 len = tree_entry_len(n);
131 info = info->prev;
132 pathlen -= len;
134 return path;
137 struct tree_desc_skip {
138 struct tree_desc_skip *prev;
139 const void *ptr;
142 struct tree_desc_x {
143 struct tree_desc d;
144 struct tree_desc_skip *skip;
147 static int check_entry_match(const char *a, int a_len, const char *b, int b_len)
150 * The caller wants to pick *a* from a tree or nothing.
151 * We are looking at *b* in a tree.
153 * (0) If a and b are the same name, we are trivially happy.
155 * There are three possibilities where *a* could be hiding
156 * behind *b*.
158 * (1) *a* == "t", *b* == "ab" i.e. *b* sorts earlier than *a* no
159 * matter what.
160 * (2) *a* == "t", *b* == "t-2" and "t" is a subtree in the tree;
161 * (3) *a* == "t-2", *b* == "t" and "t-2" is a blob in the tree.
163 * Otherwise we know *a* won't appear in the tree without
164 * scanning further.
167 int cmp = name_compare(a, a_len, b, b_len);
169 /* Most common case first -- reading sync'd trees */
170 if (!cmp)
171 return cmp;
173 if (0 < cmp) {
174 /* a comes after b; it does not matter if it is case (3)
175 if (b_len < a_len && !memcmp(a, b, b_len) && a[b_len] < '/')
176 return 1;
178 return 1; /* keep looking */
181 /* b comes after a; are we looking at case (2)? */
182 if (a_len < b_len && !memcmp(a, b, a_len) && b[a_len] < '/')
183 return 1; /* keep looking */
185 return -1; /* a cannot appear in the tree */
189 * From the extended tree_desc, extract the first name entry, while
190 * paying attention to the candidate "first" name. Most importantly,
191 * when looking for an entry, if there are entries that sorts earlier
192 * in the tree object representation than that name, skip them and
193 * process the named entry first. We will remember that we haven't
194 * processed the first entry yet, and in the later call skip the
195 * entry we processed early when update_extended_entry() is called.
197 * E.g. if the underlying tree object has these entries:
199 * blob "t-1"
200 * blob "t-2"
201 * tree "t"
202 * blob "t=1"
204 * and the "first" asks for "t", remember that we still need to
205 * process "t-1" and "t-2" but extract "t". After processing the
206 * entry "t" from this call, the caller will let us know by calling
207 * update_extended_entry() that we can remember "t" has been processed
208 * already.
211 static void extended_entry_extract(struct tree_desc_x *t,
212 struct name_entry *a,
213 const char *first,
214 int first_len)
216 const char *path;
217 int len;
218 struct tree_desc probe;
219 struct tree_desc_skip *skip;
222 * Extract the first entry from the tree_desc, but skip the
223 * ones that we already returned in earlier rounds.
225 while (1) {
226 if (!t->d.size) {
227 entry_clear(a);
228 break; /* not found */
230 entry_extract(&t->d, a);
231 for (skip = t->skip; skip; skip = skip->prev)
232 if (a->path == skip->ptr)
233 break; /* found */
234 if (!skip)
235 break;
236 /* We have processed this entry already. */
237 update_tree_entry(&t->d);
240 if (!first || !a->path)
241 return;
244 * The caller wants "first" from this tree, or nothing.
246 path = a->path;
247 len = tree_entry_len(a);
248 switch (check_entry_match(first, first_len, path, len)) {
249 case -1:
250 entry_clear(a);
251 case 0:
252 return;
253 default:
254 break;
258 * We need to look-ahead -- we suspect that a subtree whose
259 * name is "first" may be hiding behind the current entry "path".
261 probe = t->d;
262 while (probe.size) {
263 entry_extract(&probe, a);
264 path = a->path;
265 len = tree_entry_len(a);
266 switch (check_entry_match(first, first_len, path, len)) {
267 case -1:
268 entry_clear(a);
269 case 0:
270 return;
271 default:
272 update_tree_entry(&probe);
273 break;
275 /* keep looking */
277 entry_clear(a);
280 static void update_extended_entry(struct tree_desc_x *t, struct name_entry *a)
282 if (t->d.entry.path == a->path) {
283 update_tree_entry(&t->d);
284 } else {
285 /* we have returned this entry early */
286 struct tree_desc_skip *skip = xmalloc(sizeof(*skip));
287 skip->ptr = a->path;
288 skip->prev = t->skip;
289 t->skip = skip;
293 static void free_extended_entry(struct tree_desc_x *t)
295 struct tree_desc_skip *p, *s;
297 for (s = t->skip; s; s = p) {
298 p = s->prev;
299 free(s);
303 static inline int prune_traversal(struct name_entry *e,
304 struct traverse_info *info,
305 struct strbuf *base,
306 int still_interesting)
308 if (!info->pathspec || still_interesting == 2)
309 return 2;
310 if (still_interesting < 0)
311 return still_interesting;
312 return tree_entry_interesting(e, base, 0, info->pathspec);
315 int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
317 int error = 0;
318 struct name_entry *entry = xmalloc(n*sizeof(*entry));
319 int i;
320 struct tree_desc_x *tx = xcalloc(n, sizeof(*tx));
321 struct strbuf base = STRBUF_INIT;
322 int interesting = 1;
324 for (i = 0; i < n; i++)
325 tx[i].d = t[i];
327 if (info->prev) {
328 strbuf_grow(&base, info->pathlen);
329 make_traverse_path(base.buf, info->prev, &info->name);
330 base.buf[info->pathlen-1] = '/';
331 strbuf_setlen(&base, info->pathlen);
333 for (;;) {
334 int trees_used;
335 unsigned long mask, dirmask;
336 const char *first = NULL;
337 int first_len = 0;
338 struct name_entry *e = NULL;
339 int len;
341 for (i = 0; i < n; i++) {
342 e = entry + i;
343 extended_entry_extract(tx + i, e, NULL, 0);
347 * A tree may have "t-2" at the current location even
348 * though it may have "t" that is a subtree behind it,
349 * and another tree may return "t". We want to grab
350 * all "t" from all trees to match in such a case.
352 for (i = 0; i < n; i++) {
353 e = entry + i;
354 if (!e->path)
355 continue;
356 len = tree_entry_len(e);
357 if (!first) {
358 first = e->path;
359 first_len = len;
360 continue;
362 if (name_compare(e->path, len, first, first_len) < 0) {
363 first = e->path;
364 first_len = len;
368 if (first) {
369 for (i = 0; i < n; i++) {
370 e = entry + i;
371 extended_entry_extract(tx + i, e, first, first_len);
372 /* Cull the ones that are not the earliest */
373 if (!e->path)
374 continue;
375 len = tree_entry_len(e);
376 if (name_compare(e->path, len, first, first_len))
377 entry_clear(e);
381 /* Now we have in entry[i] the earliest name from the trees */
382 mask = 0;
383 dirmask = 0;
384 for (i = 0; i < n; i++) {
385 if (!entry[i].path)
386 continue;
387 mask |= 1ul << i;
388 if (S_ISDIR(entry[i].mode))
389 dirmask |= 1ul << i;
390 e = &entry[i];
392 if (!mask)
393 break;
394 interesting = prune_traversal(e, info, &base, interesting);
395 if (interesting < 0)
396 break;
397 if (interesting) {
398 trees_used = info->fn(n, mask, dirmask, entry, info);
399 if (trees_used < 0) {
400 error = trees_used;
401 if (!info->show_all_errors)
402 break;
404 mask &= trees_used;
406 for (i = 0; i < n; i++)
407 if (mask & (1ul << i))
408 update_extended_entry(tx + i, entry + i);
410 free(entry);
411 for (i = 0; i < n; i++)
412 free_extended_entry(tx + i);
413 free(tx);
414 strbuf_release(&base);
415 return error;
418 static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char *result, unsigned *mode)
420 int namelen = strlen(name);
421 while (t->size) {
422 const char *entry;
423 const unsigned char *sha1;
424 int entrylen, cmp;
426 sha1 = tree_entry_extract(t, &entry, mode);
427 entrylen = tree_entry_len(&t->entry);
428 update_tree_entry(t);
429 if (entrylen > namelen)
430 continue;
431 cmp = memcmp(name, entry, entrylen);
432 if (cmp > 0)
433 continue;
434 if (cmp < 0)
435 break;
436 if (entrylen == namelen) {
437 hashcpy(result, sha1);
438 return 0;
440 if (name[entrylen] != '/')
441 continue;
442 if (!S_ISDIR(*mode))
443 break;
444 if (++entrylen == namelen) {
445 hashcpy(result, sha1);
446 return 0;
448 return get_tree_entry(sha1, name + entrylen, result, mode);
450 return -1;
453 int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned char *sha1, unsigned *mode)
455 int retval;
456 void *tree;
457 unsigned long size;
458 unsigned char root[20];
460 tree = read_object_with_reference(tree_sha1, tree_type, &size, root);
461 if (!tree)
462 return -1;
464 if (name[0] == '\0') {
465 hashcpy(sha1, root);
466 free(tree);
467 return 0;
470 if (!size) {
471 retval = -1;
472 } else {
473 struct tree_desc t;
474 init_tree_desc(&t, tree, size);
475 retval = find_tree_entry(&t, name, sha1, mode);
477 free(tree);
478 return retval;
481 static int match_entry(const struct pathspec_item *item,
482 const struct name_entry *entry, int pathlen,
483 const char *match, int matchlen,
484 enum interesting *never_interesting)
486 int m = -1; /* signals that we haven't called strncmp() */
488 if (item->magic & PATHSPEC_ICASE)
490 * "Never interesting" trick requires exact
491 * matching. We could do something clever with inexact
492 * matching, but it's trickier (and not to forget that
493 * strcasecmp is locale-dependent, at least in
494 * glibc). Just disable it for now. It can't be worse
495 * than the wildcard's codepath of '[Tt][Hi][Is][Ss]'
496 * pattern.
498 *never_interesting = entry_not_interesting;
499 else if (*never_interesting != entry_not_interesting) {
501 * We have not seen any match that sorts later
502 * than the current path.
506 * Does match sort strictly earlier than path
507 * with their common parts?
509 m = strncmp(match, entry->path,
510 (matchlen < pathlen) ? matchlen : pathlen);
511 if (m < 0)
512 return 0;
515 * If we come here even once, that means there is at
516 * least one pathspec that would sort equal to or
517 * later than the path we are currently looking at.
518 * In other words, if we have never reached this point
519 * after iterating all pathspecs, it means all
520 * pathspecs are either outside of base, or inside the
521 * base but sorts strictly earlier than the current
522 * one. In either case, they will never match the
523 * subsequent entries. In such a case, we initialized
524 * the variable to -1 and that is what will be
525 * returned, allowing the caller to terminate early.
527 *never_interesting = entry_not_interesting;
530 if (pathlen > matchlen)
531 return 0;
533 if (matchlen > pathlen) {
534 if (match[pathlen] != '/')
535 return 0;
536 if (!S_ISDIR(entry->mode) && !S_ISGITLINK(entry->mode))
537 return 0;
540 if (m == -1)
542 * we cheated and did not do strncmp(), so we do
543 * that here.
545 m = ps_strncmp(item, match, entry->path, pathlen);
548 * If common part matched earlier then it is a hit,
549 * because we rejected the case where path is not a
550 * leading directory and is shorter than match.
552 if (!m)
554 * match_entry does not check if the prefix part is
555 * matched case-sensitively. If the entry is a
556 * directory and part of prefix, it'll be rematched
557 * eventually by basecmp with special treatment for
558 * the prefix.
560 return 1;
562 return 0;
565 /* :(icase)-aware string compare */
566 static int basecmp(const struct pathspec_item *item,
567 const char *base, const char *match, int len)
569 if (item->magic & PATHSPEC_ICASE) {
570 int ret, n = len > item->prefix ? item->prefix : len;
571 ret = strncmp(base, match, n);
572 if (ret)
573 return ret;
574 base += n;
575 match += n;
576 len -= n;
578 return ps_strncmp(item, base, match, len);
581 static int match_dir_prefix(const struct pathspec_item *item,
582 const char *base,
583 const char *match, int matchlen)
585 if (basecmp(item, base, match, matchlen))
586 return 0;
589 * If the base is a subdirectory of a path which
590 * was specified, all of them are interesting.
592 if (!matchlen ||
593 base[matchlen] == '/' ||
594 match[matchlen - 1] == '/')
595 return 1;
597 /* Just a random prefix match */
598 return 0;
602 * Perform matching on the leading non-wildcard part of
603 * pathspec. item->nowildcard_len must be greater than zero. Return
604 * non-zero if base is matched.
606 static int match_wildcard_base(const struct pathspec_item *item,
607 const char *base, int baselen,
608 int *matched)
610 const char *match = item->match;
611 /* the wildcard part is not considered in this function */
612 int matchlen = item->nowildcard_len;
614 if (baselen) {
615 int dirlen;
617 * Return early if base is longer than the
618 * non-wildcard part but it does not match.
620 if (baselen >= matchlen) {
621 *matched = matchlen;
622 return !basecmp(item, base, match, matchlen);
625 dirlen = matchlen;
626 while (dirlen && match[dirlen - 1] != '/')
627 dirlen--;
630 * Return early if base is shorter than the
631 * non-wildcard part but it does not match. Note that
632 * base ends with '/' so we are sure it really matches
633 * directory
635 if (basecmp(item, base, match, baselen))
636 return 0;
637 *matched = baselen;
638 } else
639 *matched = 0;
641 * we could have checked entry against the non-wildcard part
642 * that is not in base and does similar never_interesting
643 * optimization as in match_entry. For now just be happy with
644 * base comparison.
646 return entry_interesting;
650 * Is a tree entry interesting given the pathspec we have?
652 * Pre-condition: either baselen == base_offset (i.e. empty path)
653 * or base[baselen-1] == '/' (i.e. with trailing slash).
655 static enum interesting do_match(const struct name_entry *entry,
656 struct strbuf *base, int base_offset,
657 const struct pathspec *ps,
658 int exclude)
660 int i;
661 int pathlen, baselen = base->len - base_offset;
662 enum interesting never_interesting = ps->has_wildcard ?
663 entry_not_interesting : all_entries_not_interesting;
665 GUARD_PATHSPEC(ps,
666 PATHSPEC_FROMTOP |
667 PATHSPEC_MAXDEPTH |
668 PATHSPEC_LITERAL |
669 PATHSPEC_GLOB |
670 PATHSPEC_ICASE |
671 PATHSPEC_EXCLUDE);
673 if (!ps->nr) {
674 if (!ps->recursive ||
675 !(ps->magic & PATHSPEC_MAXDEPTH) ||
676 ps->max_depth == -1)
677 return all_entries_interesting;
678 return within_depth(base->buf + base_offset, baselen,
679 !!S_ISDIR(entry->mode),
680 ps->max_depth) ?
681 entry_interesting : entry_not_interesting;
684 pathlen = tree_entry_len(entry);
686 for (i = ps->nr - 1; i >= 0; i--) {
687 const struct pathspec_item *item = ps->items+i;
688 const char *match = item->match;
689 const char *base_str = base->buf + base_offset;
690 int matchlen = item->len, matched = 0;
692 if ((!exclude && item->magic & PATHSPEC_EXCLUDE) ||
693 ( exclude && !(item->magic & PATHSPEC_EXCLUDE)))
694 continue;
696 if (baselen >= matchlen) {
697 /* If it doesn't match, move along... */
698 if (!match_dir_prefix(item, base_str, match, matchlen))
699 goto match_wildcards;
701 if (!ps->recursive ||
702 !(ps->magic & PATHSPEC_MAXDEPTH) ||
703 ps->max_depth == -1)
704 return all_entries_interesting;
706 return within_depth(base_str + matchlen + 1,
707 baselen - matchlen - 1,
708 !!S_ISDIR(entry->mode),
709 ps->max_depth) ?
710 entry_interesting : entry_not_interesting;
713 /* Either there must be no base, or the base must match. */
714 if (baselen == 0 || !basecmp(item, base_str, match, baselen)) {
715 if (match_entry(item, entry, pathlen,
716 match + baselen, matchlen - baselen,
717 &never_interesting))
718 return entry_interesting;
720 if (item->nowildcard_len < item->len) {
721 if (!git_fnmatch(item, match + baselen, entry->path,
722 item->nowildcard_len - baselen))
723 return entry_interesting;
726 * Match all directories. We'll try to
727 * match files later on.
729 if (ps->recursive && S_ISDIR(entry->mode))
730 return entry_interesting;
733 continue;
736 match_wildcards:
737 if (item->nowildcard_len == item->len)
738 continue;
740 if (item->nowildcard_len &&
741 !match_wildcard_base(item, base_str, baselen, &matched))
742 continue;
745 * Concatenate base and entry->path into one and do
746 * fnmatch() on it.
748 * While we could avoid concatenation in certain cases
749 * [1], which saves a memcpy and potentially a
750 * realloc, it turns out not worth it. Measurement on
751 * linux-2.6 does not show any clear improvements,
752 * partly because of the nowildcard_len optimization
753 * in git_fnmatch(). Avoid micro-optimizations here.
755 * [1] if match_wildcard_base() says the base
756 * directory is already matched, we only need to match
757 * the rest, which is shorter so _in theory_ faster.
760 strbuf_add(base, entry->path, pathlen);
762 if (!git_fnmatch(item, match, base->buf + base_offset,
763 item->nowildcard_len)) {
764 strbuf_setlen(base, base_offset + baselen);
765 return entry_interesting;
767 strbuf_setlen(base, base_offset + baselen);
770 * Match all directories. We'll try to match files
771 * later on.
772 * max_depth is ignored but we may consider support it
773 * in future, see
774 * http://thread.gmane.org/gmane.comp.version-control.git/163757/focus=163840
776 if (ps->recursive && S_ISDIR(entry->mode))
777 return entry_interesting;
779 return never_interesting; /* No matches */
783 * Is a tree entry interesting given the pathspec we have?
785 * Pre-condition: either baselen == base_offset (i.e. empty path)
786 * or base[baselen-1] == '/' (i.e. with trailing slash).
788 enum interesting tree_entry_interesting(const struct name_entry *entry,
789 struct strbuf *base, int base_offset,
790 const struct pathspec *ps)
792 enum interesting positive, negative;
793 positive = do_match(entry, base, base_offset, ps, 0);
796 * case | entry | positive | negative | result
797 * -----+-------+----------+----------+-------
798 * 1 | file | -1 | -1..2 | -1
799 * 2 | file | 0 | -1..2 | 0
800 * 3 | file | 1 | -1 | 1
801 * 4 | file | 1 | 0 | 1
802 * 5 | file | 1 | 1 | 0
803 * 6 | file | 1 | 2 | 0
804 * 7 | file | 2 | -1 | 2
805 * 8 | file | 2 | 0 | 2
806 * 9 | file | 2 | 1 | 0
807 * 10 | file | 2 | 2 | -1
808 * -----+-------+----------+----------+-------
809 * 11 | dir | -1 | -1..2 | -1
810 * 12 | dir | 0 | -1..2 | 0
811 * 13 | dir | 1 | -1 | 1
812 * 14 | dir | 1 | 0 | 1
813 * 15 | dir | 1 | 1 | 1 (*)
814 * 16 | dir | 1 | 2 | 0
815 * 17 | dir | 2 | -1 | 2
816 * 18 | dir | 2 | 0 | 2
817 * 19 | dir | 2 | 1 | 1 (*)
818 * 20 | dir | 2 | 2 | -1
820 * (*) An exclude pattern interested in a directory does not
821 * necessarily mean it will exclude all of the directory. In
822 * wildcard case, it can't decide until looking at individual
823 * files inside. So don't write such directories off yet.
826 if (!(ps->magic & PATHSPEC_EXCLUDE) ||
827 positive <= entry_not_interesting) /* #1, #2, #11, #12 */
828 return positive;
830 negative = do_match(entry, base, base_offset, ps, 1);
832 /* #3, #4, #7, #8, #13, #14, #17, #18 */
833 if (negative <= entry_not_interesting)
834 return positive;
836 /* #15, #19 */
837 if (S_ISDIR(entry->mode) &&
838 positive >= entry_interesting &&
839 negative == entry_interesting)
840 return entry_interesting;
842 if ((positive == entry_interesting &&
843 negative >= entry_interesting) || /* #5, #6, #16 */
844 (positive == all_entries_interesting &&
845 negative == entry_interesting)) /* #9 */
846 return entry_not_interesting;
848 return all_entries_not_interesting; /* #10, #20 */