Commit 2f188290e2

Ryan Liptak <squeek502@hotmail.com>
2023-06-08 07:37:53
Use `iterateAssumeFirstIteration` in `Walker.next` to avoid unnecessary lseek calls
Since we are opening each directory for iteration, we know that we don't need to reset the cursor's directory before iterating. Using `iterateAssumeFirstIteration` skips the cursor resetting which eliminates an `lseek` syscall for every directory opened on non-Windows platforms. This doesn't seem to actually matter much for performance (1.01 ± 0.02 times faster when walking /home/ on my system) but avoiding unnecessary syscalls is always nice anyway.
master
1 parent 00ff653
Changed files (1)
lib
std
fs.zig
lib/std/fs.zig
@@ -972,7 +972,7 @@ pub const IterableDir = struct {
                         {
                             errdefer new_dir.close();
                             try self.stack.append(StackItem{
-                                .iter = new_dir.iterate(),
+                                .iter = new_dir.iterateAssumeFirstIteration(),
                                 .dirname_len = self.name_buffer.items.len,
                             });
                             top = &self.stack.items[self.stack.items.len - 1];