[PATCH 4/5] tree_entry_interesting(): remove dependency on struct diff_options

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

This function can be potentially used in more places than just
tree-diff.c. "struct diff_options" does not make much sense outside
diff_tree_sha1().

Moreover people seem to be agree that diff machinery should learn
proper pathspecs too (i.e. glob support [1] and stuff), not just
treating pathspecs as tree prefix.

So instead of using pathspecs in
diff_options.{nr_paths,paths,pathlens}, tree_entry_interesting() now
uses struct exclude_list.

Struct exclude_list is also added to diff_options with the intention
to replace {nr_paths,paths,pathlens} later on. But for now, it's just
a temporary field.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 diff.h      |    3 +++
 tree-diff.c |   31 ++++++++++++++++++++++++++++---
 tree-walk.c |   26 +++++++++++---------------
 tree-walk.h |    5 +++--
 4 files changed, 45 insertions(+), 20 deletions(-)

diff --git a/diff.h b/diff.h
index bf2f44d..bd8fe9e 100644
--- a/diff.h
+++ b/diff.h
@@ -5,6 +5,7 @@
 #define DIFF_H
 
 #include "tree-walk.h"
+#include "dir.h"
 
 struct rev_info;
 struct diff_options;
@@ -136,6 +137,7 @@ struct diff_options {
 	int nr_paths;
 	const char **paths;
 	int *pathlens;
+	struct exclude_list el;
 	change_fn_t change;
 	add_remove_fn_t add_remove;
 	diff_format_fn_t format_callback;
@@ -163,6 +165,7 @@ const char *diff_get_color(int diff_use_color, enum color_diff ix);
 extern const char mime_boundary_leader[];
 
 extern void diff_tree_setup_paths(const char **paths, struct diff_options *);
+extern void diff_tree_setup_exclude_list(struct diff_options *);
 extern void diff_tree_release_paths(struct diff_options *);
 extern int diff_tree(struct tree_desc *t1, struct tree_desc *t2,
 		     const char *base, struct diff_options *opt);
diff --git a/tree-diff.c b/tree-diff.c
index c74d0b5..c2951af 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -92,8 +92,7 @@ static void show_tree(struct diff_options *opt, const char *prefix, struct tree_
 		if (all_interesting)
 			show = 1;
 		else {
-			show = tree_entry_interesting(desc, base, baselen,
-						      opt);
+			show = tree_entry_interesting(&desc->entry, base, baselen, &opt->el);
 			if (show == 2)
 				all_interesting = 1;
 		}
@@ -152,7 +151,7 @@ static void skip_uninteresting(struct tree_desc *t, const char *base, int basele
 		if (all_interesting)
 			show = 1;
 		else {
-			show = tree_entry_interesting(t, base, baselen, opt);
+			show = tree_entry_interesting(&t->entry, base, baselen, &opt->el);
 			if (show == 2)
 				all_interesting = 1;
 		}
@@ -167,10 +166,34 @@ static void skip_uninteresting(struct tree_desc *t, const char *base, int basele
 	}
 }
 
+void diff_tree_setup_exclude_list(struct diff_options *opt)
+{
+	int i, size1, size2;
+
+	memset(&opt->el, 0, sizeof(opt->el));
+	opt->el.nr = opt->nr_paths;
+	if (!opt->el.nr)
+		return;
+
+	size1 = opt->el.nr * sizeof(struct exclude *);
+	size2 = opt->el.nr * sizeof(struct exclude);
+	opt->el.excludes = xmalloc(size1+size2);
+	memset(opt->el.excludes, 0, size1+size2);
+	for (i=0; i < opt->el.nr; i++) {
+		struct exclude *exc = ((struct exclude *)((char*)opt->el.excludes+size1))+i;
+		exc->base = opt->paths[i];
+		exc->baselen = opt->pathlens[i];
+		opt->el.excludes[i] = exc;
+	}
+}
+
 int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
 {
 	int baselen = strlen(base);
+	struct exclude_list el;
 
+	el = opt->el; /* diff_tree() can be nested, save and restore opt->el later */
+	diff_tree_setup_exclude_list(opt);
 	for (;;) {
 		if (DIFF_OPT_TST(opt, QUICK) &&
 		    DIFF_OPT_TST(opt, HAS_CHANGES))
@@ -204,6 +227,8 @@ int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, stru
 		}
 		die("git diff-tree: internal error");
 	}
+	free(opt->el.excludes);
+	opt->el = el;
 	return 0;
 }
 
diff --git a/tree-walk.c b/tree-walk.c
index bc83fa3..c915218 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -2,7 +2,7 @@
 #include "tree-walk.h"
 #include "unpack-trees.h"
 #include "tree.h"
-#include "diff.h"
+#include "dir.h"
 
 static const char *get_mode(const char *str, unsigned int *modep)
 {
@@ -466,25 +466,21 @@ int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned ch
  *  - zero for no
  *  - negative for "no, and no subsequent entries will be either"
  */
-static int tree_entry_interesting(struct tree_desc *desc, const char *base, int baselen, struct diff_options *opt)
+int tree_entry_interesting(const struct name_entry *entry, const char *base, int baselen,
+			   const struct exclude_list *el)
 {
-	const char *path;
-	const unsigned char *sha1;
-	unsigned mode;
 	int i;
 	int pathlen;
 	int never_interesting = -1;
 
-	if (!opt->nr_paths)
+	if (!el->nr)
 		return 1;
 
-	sha1 = tree_entry_extract(desc, &path, &mode);
-
-	pathlen = tree_entry_len(path, sha1);
+	pathlen = tree_entry_len(entry->path, entry->sha1);
 
-	for (i = 0; i < opt->nr_paths; i++) {
-		const char *match = opt->paths[i];
-		int matchlen = opt->pathlens[i];
+	for (i = 0; i < el->nr; i++) {
+		const char *match = el->excludes[i]->base;
+		int matchlen = el->excludes[i]->baselen;
 		int m = -1; /* signals that we haven't called strncmp() */
 
 		if (baselen >= matchlen) {
@@ -522,7 +518,7 @@ static int tree_entry_interesting(struct tree_desc *desc, const char *base, int
 			 * Does match sort strictly earlier than path
 			 * with their common parts?
 			 */
-			m = strncmp(match, path,
+			m = strncmp(match, entry->path,
 				    (matchlen < pathlen) ? matchlen : pathlen);
 			if (m < 0)
 				continue;
@@ -549,7 +545,7 @@ static int tree_entry_interesting(struct tree_desc *desc, const char *base, int
 		if (matchlen > pathlen) {
 			if (match[pathlen] != '/')
 				continue;
-			if (!S_ISDIR(mode))
+			if (!S_ISDIR(entry->mode))
 				continue;
 		}
 
@@ -558,7 +554,7 @@ static int tree_entry_interesting(struct tree_desc *desc, const char *base, int
 			 * we cheated and did not do strncmp(), so we do
 			 * that here.
 			 */
-			m = strncmp(match, path, pathlen);
+			m = strncmp(match, entry->path, pathlen);
 
 		/*
 		 * If common part matched earlier then it is a hit,
diff --git a/tree-walk.h b/tree-walk.h
index 0572721..4b37671 100644
--- a/tree-walk.h
+++ b/tree-walk.h
@@ -57,7 +57,8 @@ static inline int traverse_path_len(const struct traverse_info *info, const stru
 	return info->pathlen + tree_entry_len(n->path, n->sha1);
 }
 
-struct diff_options;
-extern int tree_entry_interesting(struct tree_desc *desc, const char *base, int baselen, struct diff_options *opt);
+struct exclude_list;
+extern int tree_entry_interesting(const struct name_entry *entry, const char *base, int baselen,
+				  const struct exclude_list *el);
 
 #endif
-- 
1.7.1.rc1.69.g24c2f7