From 1c110552413fce035c94e80ace5bfa4e9f216535 Mon Sep 17 00:00:00 2001
From: Fabian Boehm <FHomborg@gmail.com>
Date: Thu, 16 Jan 2025 19:32:15 +0100
Subject: [PATCH] Don't clone argv for builtins

We capture the process already, and we use argv by reference for the
other cases.

argv can be big, and this reduces allocations and thereby memory usage
and speed.

E.g. `set -l foo **` with 200k matches has 25% reduced memory usage
and ~5% reduced runtime.
---
 src/exec.rs | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/exec.rs b/src/exec.rs
index 0d8362498..0b9e9b7ba 100644
--- a/src/exec.rs
+++ b/src/exec.rs
@@ -1106,7 +1106,6 @@ fn get_performer_for_builtin(p: &Process, j: &Job, io_chain: &IoChain) -> Box<Pr
 
     // Pull out some fields which we want to copy. We don't want to store the process or job in the
     // returned closure.
-    let argv = p.argv().clone();
     let job_group = j.group.clone();
     let io_chain = io_chain.clone();
 
@@ -1114,7 +1113,7 @@ fn get_performer_for_builtin(p: &Process, j: &Job, io_chain: &IoChain) -> Box<Pr
     // thread.
     Box::new(
         move |parser: &Parser,
-              _p: &Process,
+              p: &Process,
               output_stream: Option<&mut OutputStream>,
               errput_stream: Option<&mut OutputStream>| {
             let output_stream = output_stream.unwrap();
@@ -1151,8 +1150,11 @@ fn get_performer_for_builtin(p: &Process, j: &Job, io_chain: &IoChain) -> Box<Pr
                 .unwrap_or(false);
 
             // Execute the builtin.
-            let mut shim_argv: Vec<&wstr> =
-                argv.iter().map(|s| truncate_at_nul(s.as_ref())).collect();
+            let mut shim_argv: Vec<&wstr> = p
+                .argv()
+                .iter()
+                .map(|s| truncate_at_nul(s.as_ref()))
+                .collect();
             builtin_run(parser, &mut shim_argv, &mut streams)
         },
     )