Optimize DirAccessUnix::get_next() for some file systems

On some file systems, like ext4 on Linux, readdir() gives enough
information to determine the entry type in order to avoid doing
a stat() system call.

Use this information and call stat() only if necessary.

1 files changed, 14 insertions, 10 deletions

diff --git a/drivers/unix/dir_access_unix.cpp b/drivers/unix/dir_access_unix.cpp
index 251bab5783..d5582d00ed 100644
--- a/drivers/unix/dir_access_unix.cpp
+++ b/drivers/unix/dir_access_unix.cpp
@@ -136,27 +136,31 @@ String DirAccessUnix::get_next() {
 		return "";
 	}
 
-	//typedef struct stat Stat;
-	struct stat flags;
-
 	String fname = fix_unicode_name(entry->d_name);
 
-	String f = current_dir.plus_file(fname);
+	if (entry->d_type == DT_UNKNOWN) {
+		//typedef struct stat Stat;
+		struct stat flags;
+
+		String f = current_dir.plus_file(fname);
+
+		if (stat(f.utf8().get_data(), &flags) == 0) {
 
-	if (stat(f.utf8().get_data(), &flags) == 0) {
+			if (S_ISDIR(flags.st_mode)) {
 
-		if (S_ISDIR(flags.st_mode)) {
+				_cisdir = true;
 
-			_cisdir = true;
+			} else {
+
+				_cisdir = false;
+			}
 
 		} else {
 
 			_cisdir = false;
 		}
-
 	} else {
-
-		_cisdir = false;
+		_cisdir = (entry->d_type == DT_DIR);
 	}
 
 	_cishidden = (fname != "." && fname != ".." && fname.begins_with("."));