Merge branch 'nd/pathspec-wildcard'

Optimize matching paths with common forms of pathspecs that contain
wildcard characters.

* nd/pathspec-wildcard:
  tree_entry_interesting: do basedir compare on wildcard patterns when possible
  pathspec: apply "*.c" optimization from exclude
  pathspec: do exact comparison on the leading non-wildcard part
  pathspec: save the non-wildcard length part

builtin/ls-files.c

@@ -337,7 +337,7 @@ void overlay_tree_on_cache(const char *tree_name, const char *prefix)
 		matchbuf[0] = prefix;
 		matchbuf[1] = NULL;
 		init_pathspec(&pathspec, matchbuf);
-		pathspec.items[0].use_wildcard = 0;
+		pathspec.items[0].nowildcard_len = pathspec.items[0].len;
 	} else
 		init_pathspec(&pathspec, NULL);
 	if (read_tree(tree, 1, &pathspec))

builtin/ls-tree.c

@@ -168,7 +168,7 @@ int cmd_ls_tree(int argc, const char **argv, const char *prefix)
 
 	init_pathspec(&pathspec, get_pathspec(prefix, argv + 1));
 	for (i = 0; i < pathspec.nr; i++)
-		pathspec.items[i].use_wildcard = 0;
+		pathspec.items[i].nowildcard_len = pathspec.items[i].len;
 	pathspec.has_wildcard = 0;
 	tree = parse_tree_indirect(sha1);
 	if (!tree)

cache.h

@@ -473,6 +473,8 @@ extern int index_name_is_other(const struct index_state *, const char *, int);
 extern int ie_match_stat(const struct index_state *, struct cache_entry *, struct stat *, unsigned int);
 extern int ie_modified(const struct index_state *, struct cache_entry *, struct stat *, unsigned int);
 
+#define PATHSPEC_ONESTAR 1	/* the pathspec pattern sastisfies GFNM_ONESTAR */
+
 struct pathspec {
 	const char **raw; /* get_pathspec() result, not freed by free_pathspec() */
 	int nr;
@@ -482,7 +484,8 @@ struct pathspec {
 	struct pathspec_item {
 		const char *match;
 		int len;
-		unsigned int use_wildcard:1;
+		int nowildcard_len;
+		int flags;
 	} *items;
 };
 

dir.c

@@ -34,6 +34,28 @@ int fnmatch_icase(const char *pattern, const char *string, int flags)
 	return fnmatch(pattern, string, flags | (ignore_case ? FNM_CASEFOLD : 0));
 }
 
+inline int git_fnmatch(const char *pattern, const char *string,
+		       int flags, int prefix)
+{
+	int fnm_flags = 0;
+	if (flags & GFNM_PATHNAME)
+		fnm_flags |= FNM_PATHNAME;
+	if (prefix > 0) {
+		if (strncmp(pattern, string, prefix))
+			return FNM_NOMATCH;
+		pattern += prefix;
+		string += prefix;
+	}
+	if (flags & GFNM_ONESTAR) {
+		int pattern_len = strlen(++pattern);
+		int string_len = strlen(string);
+		return string_len < pattern_len ||
+		       strcmp(pattern,
+			      string + string_len - pattern_len);
+	}
+	return fnmatch(pattern, string, fnm_flags);
+}
+
 static size_t common_prefix_len(const char **pathspec)
 {
 	const char *n, *first;
@@ -230,7 +252,10 @@ static int match_pathspec_item(const struct pathspec_item *item, int prefix,
 			return MATCHED_RECURSIVELY;
 	}
 
-	if (item->use_wildcard && !fnmatch(match, name, 0))
+	if (item->nowildcard_len < item->len &&
+	    !git_fnmatch(match, name,
+			 item->flags & PATHSPEC_ONESTAR ? GFNM_ONESTAR : 0,
+			 item->nowildcard_len - prefix))
 		return MATCHED_FNMATCH;
 
 	return 0;
@@ -1429,9 +1454,14 @@ int init_pathspec(struct pathspec *pathspec, const char **paths)
 
 		item->match = path;
 		item->len = strlen(path);
-		item->use_wildcard = !no_wildcard(path);
-		if (item->use_wildcard)
+		item->nowildcard_len = simple_length(path);
+		item->flags = 0;
+		if (item->nowildcard_len < item->len) {
 			pathspec->has_wildcard = 1;
+			if (path[item->nowildcard_len] == '*' &&
+			    no_wildcard(path + item->nowildcard_len + 1))
+				item->flags |= PATHSPEC_ONESTAR;
+		}
 	}
 
 	qsort(pathspec->items, pathspec->nr,

dir.h

@@ -139,4 +139,13 @@ extern int strcmp_icase(const char *a, const char *b);
 extern int strncmp_icase(const char *a, const char *b, size_t count);
 extern int fnmatch_icase(const char *pattern, const char *string, int flags);
 
+/*
+ * The prefix part of pattern must not contains wildcards.
+ */
+#define GFNM_PATHNAME 1		/* similar to FNM_PATHNAME */
+#define GFNM_ONESTAR  2		/* there is only _one_ wildcard, a star */
+
+extern int git_fnmatch(const char *pattern, const char *string,
+		       int flags, int prefix);
+
 #endif

tree-walk.c

@@ -572,6 +572,54 @@ static int match_dir_prefix(const char *base,
 	return 0;
 }
 
+/*
+ * Perform matching on the leading non-wildcard part of
+ * pathspec. item->nowildcard_len must be greater than zero. Return
+ * non-zero if base is matched.
+ */
+static int match_wildcard_base(const struct pathspec_item *item,
+			       const char *base, int baselen,
+			       int *matched)
+{
+	const char *match = item->match;
+	/* the wildcard part is not considered in this function */
+	int matchlen = item->nowildcard_len;
+
+	if (baselen) {
+		int dirlen;
+		/*
+		 * Return early if base is longer than the
+		 * non-wildcard part but it does not match.
+		 */
+		if (baselen >= matchlen) {
+			*matched = matchlen;
+			return !strncmp(base, match, matchlen);
+		}
+
+		dirlen = matchlen;
+		while (dirlen && match[dirlen - 1] != '/')
+			dirlen--;
+
+		/*
+		 * Return early if base is shorter than the
+		 * non-wildcard part but it does not match. Note that
+		 * base ends with '/' so we are sure it really matches
+		 * directory
+		 */
+		if (strncmp(base, match, baselen))
+			return 0;
+		*matched = baselen;
+	} else
+		*matched = 0;
+	/*
+	 * we could have checked entry against the non-wildcard part
+	 * that is not in base and does similar never_interesting
+	 * optimization as in match_entry. For now just be happy with
+	 * base comparison.
+	 */
+	return entry_interesting;
+}
+
 /*
  * Is a tree entry interesting given the pathspec we have?
  *
@@ -602,7 +650,7 @@ enum interesting tree_entry_interesting(const struct name_entry *entry,
 		const struct pathspec_item *item = ps->items+i;
 		const char *match = item->match;
 		const char *base_str = base->buf + base_offset;
-		int matchlen = item->len;
+		int matchlen = item->len, matched = 0;
 
 		if (baselen >= matchlen) {
 			/* If it doesn't match, move along... */
@@ -626,8 +674,10 @@ enum interesting tree_entry_interesting(const struct name_entry *entry,
 					&never_interesting))
 				return entry_interesting;
 
-			if (item->use_wildcard) {
-				if (!fnmatch(match + baselen, entry->path, 0))
+			if (item->nowildcard_len < item->len) {
+				if (!git_fnmatch(match + baselen, entry->path,
+						 item->flags & PATHSPEC_ONESTAR ? GFNM_ONESTAR : 0,
+						 item->nowildcard_len - baselen))
 					return entry_interesting;
 
 				/*
@@ -642,17 +692,34 @@ enum interesting tree_entry_interesting(const struct name_entry *entry,
 		}
 
 match_wildcards:
-		if (!item->use_wildcard)
+		if (item->nowildcard_len == item->len)
 			continue;
 
+		if (item->nowildcard_len &&
+		    !match_wildcard_base(item, base_str, baselen, &matched))
+			return entry_not_interesting;
+
 		/*
 		 * Concatenate base and entry->path into one and do
 		 * fnmatch() on it.
+		 *
+		 * While we could avoid concatenation in certain cases
+		 * [1], which saves a memcpy and potentially a
+		 * realloc, it turns out not worth it. Measurement on
+		 * linux-2.6 does not show any clear improvements,
+		 * partly because of the nowildcard_len optimization
+		 * in git_fnmatch(). Avoid micro-optimizations here.
+		 *
+		 * [1] if match_wildcard_base() says the base
+		 * directory is already matched, we only need to match
+		 * the rest, which is shorter so _in theory_ faster.
 		 */
 
 		strbuf_add(base, entry->path, pathlen);
 
-		if (!fnmatch(match, base->buf + base_offset, 0)) {
+		if (!git_fnmatch(match, base->buf + base_offset,
+				 item->flags & PATHSPEC_ONESTAR ? GFNM_ONESTAR : 0,
+				 item->nowildcard_len)) {
 			strbuf_setlen(base, base_offset + baselen);
 			return entry_interesting;
 		}