From 3a2d8889131b15bdc23721c91fb46d50db0a1aae Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Mon, 16 Aug 2021 22:18:18 +0200
Subject: [PATCH] Kernel/DevPtsFS: Avoid String allocation during directory
 traversal

Use a StringBuilder to generate a temporary string buffer with the
slave PTY names. (This works because StringBuilder has 128 bytes of
inline stack capacity before it does any heap allocations.)
---
 Kernel/FileSystem/DevPtsFS.cpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Kernel/FileSystem/DevPtsFS.cpp b/Kernel/FileSystem/DevPtsFS.cpp
index 136a39afa2..07f56d2e3f 100644
--- a/Kernel/FileSystem/DevPtsFS.cpp
+++ b/Kernel/FileSystem/DevPtsFS.cpp
@@ -118,9 +118,9 @@ KResult DevPtsFSInode::traverse_as_directory(Function<bool(FileSystem::Directory
 
     SlavePTY::all_instances().with([&](auto& list) {
         for (SlavePTY& slave_pty : list) {
-            String name = String::number(slave_pty.index());
-            InodeIdentifier identifier = { fsid(), pty_index_to_inode_index(slave_pty.index()) };
-            callback({ name, identifier, 0 });
+            StringBuilder builder;
+            builder.appendff("{}", slave_pty.index());
+            callback({ builder.string_view(), { fsid(), pty_index_to_inode_index(slave_pty.index()) }, 0 });
         }
     });