From 5664ee7bdaaeaf124499697310cc2ddbf5955306 Mon Sep 17 00:00:00 2001
From: Reilly Wood <26268125+rgwood@users.noreply.github.com>
Date: Tue, 10 Jan 2023 17:22:32 -0800
Subject: [PATCH] Remove `engine_state` clones in REPL eval (#7713)

A small but easy optimization for `evaluate_repl()`: clone
`engine_state` 1x instead of 3x.

This reduces time spent in a simple REPL eval (`enter` key pressed with
no command text) by about 10%, as measured in
[Superluminal](https://superluminal.eu/).
---
 crates/nu-cli/src/nu_highlight.rs     | 2 +-
 crates/nu-cli/src/repl.rs             | 4 ++--
 crates/nu-cli/src/syntax_highlight.rs | 3 ++-
 crates/nu-cli/src/validation.rs       | 3 ++-
 4 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/crates/nu-cli/src/nu_highlight.rs b/crates/nu-cli/src/nu_highlight.rs
index 17a0ae53d..5c1e74f77 100644
--- a/crates/nu-cli/src/nu_highlight.rs
+++ b/crates/nu-cli/src/nu_highlight.rs
@@ -35,7 +35,7 @@ impl Command for NuHighlight {
         let head = call.head;
 
         let ctrlc = engine_state.ctrlc.clone();
-        let engine_state = engine_state.clone();
+        let engine_state = std::sync::Arc::new(engine_state.clone());
         let config = engine_state.get_config().clone();
 
         let highlighter = crate::NuHighlighter {
diff --git a/crates/nu-cli/src/repl.rs b/crates/nu-cli/src/repl.rs
index 851be4450..9d5acda29 100644
--- a/crates/nu-cli/src/repl.rs
+++ b/crates/nu-cli/src/repl.rs
@@ -176,11 +176,11 @@ pub fn evaluate_repl(
         let engine_reference = std::sync::Arc::new(engine_state.clone());
         line_editor = line_editor
             .with_highlighter(Box::new(NuHighlighter {
-                engine_state: engine_state.clone(),
+                engine_state: engine_reference.clone(),
                 config: config.clone(),
             }))
             .with_validator(Box::new(NuValidator {
-                engine_state: engine_state.clone(),
+                engine_state: engine_reference.clone(),
             }))
             .with_completer(Box::new(NuCompleter::new(
                 engine_reference.clone(),
diff --git a/crates/nu-cli/src/syntax_highlight.rs b/crates/nu-cli/src/syntax_highlight.rs
index 9d2258fda..25e0384cf 100644
--- a/crates/nu-cli/src/syntax_highlight.rs
+++ b/crates/nu-cli/src/syntax_highlight.rs
@@ -6,9 +6,10 @@ use nu_protocol::ast::{Argument, Block, Expr, Expression, PipelineElement};
 use nu_protocol::engine::{EngineState, StateWorkingSet};
 use nu_protocol::{Config, Span};
 use reedline::{Highlighter, StyledText};
+use std::sync::Arc;
 
 pub struct NuHighlighter {
-    pub engine_state: EngineState,
+    pub engine_state: Arc<EngineState>,
     pub config: Config,
 }
 
diff --git a/crates/nu-cli/src/validation.rs b/crates/nu-cli/src/validation.rs
index 8b31932c3..a53e617b0 100644
--- a/crates/nu-cli/src/validation.rs
+++ b/crates/nu-cli/src/validation.rs
@@ -1,9 +1,10 @@
 use nu_parser::{parse, ParseError};
 use nu_protocol::engine::{EngineState, StateWorkingSet};
 use reedline::{ValidationResult, Validator};
+use std::sync::Arc;
 
 pub struct NuValidator {
-    pub engine_state: EngineState,
+    pub engine_state: Arc<EngineState>,
 }
 
 impl Validator for NuValidator {