archive: factor out helper functions for handling attributes

Add helpers for accessing attributes that encapsulate the details of how
to retrieve their values.

Signed-off-by: Rene Scharfe <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: rscharfe

archive.c

@@ -103,12 +103,30 @@ struct archiver_context {
 	struct directory *bottom;
 };
 
+static const struct attr_check *get_archive_attrs(const char *path)
+{
+	static struct attr_check *check;
+	if (!check)
+		check = attr_check_initl("export-ignore", "export-subst", NULL);
+	return git_check_attr(path, check) ? NULL : check;
+}
+
+static int check_attr_export_ignore(const struct attr_check *check)
+{
+	return check && ATTR_TRUE(check->items[0].value);
+}
+
+static int check_attr_export_subst(const struct attr_check *check)
+{
+	return check && ATTR_TRUE(check->items[1].value);
+}
+
 static int write_archive_entry(const unsigned char *sha1, const char *base,
 		int baselen, const char *filename, unsigned mode, int stage,
 		void *context)
 {
 	static struct strbuf path = STRBUF_INIT;
-	static struct attr_check *check;
+	const struct attr_check *check;
 	struct archiver_context *c = context;
 	struct archiver_args *args = c->args;
 	write_archive_entry_fn_t write_entry = c->write_entry;
@@ -125,13 +143,10 @@ static int write_archive_entry(const unsigned char *sha1, const char *base,
 		strbuf_addch(&path, '/');
 	path_without_prefix = path.buf + args->baselen;
 
-	if (!check)
-		check = attr_check_initl("export-ignore", "export-subst", NULL);
-	if (!git_check_attr(path_without_prefix, check)) {
-		if (ATTR_TRUE(check->items[0].value))
-			return 0;
-		args->convert = ATTR_TRUE(check->items[1].value);
-	}
+	check = get_archive_attrs(path_without_prefix);
+	if (check_attr_export_ignore(check))
+		return 0;
+	args->convert = check_attr_export_subst(check);
 
 	if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
 		if (args->verbose)