From ecbd5149f87208a27bd9ec6cfef708967d8e784a Mon Sep 17 00:00:00 2001
From: Filip Tibell <filip.tibell@gmail.com>
Date: Wed, 31 Jan 2024 20:30:18 +0100
Subject: [PATCH] Use faster hash map for thread results

---
 Cargo.lock        |  1 +
 Cargo.toml        |  1 +
 lib/result_map.rs | 18 +++++++++---------
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 9db513f..154ab27 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -338,6 +338,7 @@ dependencies = [
  "event-listener",
  "futures-lite",
  "mlua",
+ "rustc-hash",
  "tracing",
  "tracing-subscriber",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index d954505..ae7b873 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,6 +15,7 @@ concurrent-queue = "2.4"
 derive_more = "0.99"
 event-listener = "4.0"
 futures-lite = "2.2"
+rustc-hash = "1.1"
 tracing = "0.1"
 
 mlua = { version = "0.9.5", features = [
diff --git a/lib/result_map.rs b/lib/result_map.rs
index 7295f42..4d406ff 100644
--- a/lib/result_map.rs
+++ b/lib/result_map.rs
@@ -1,24 +1,24 @@
 #![allow(clippy::inline_always)]
 
-use std::{
-    cell::RefCell,
-    collections::{HashMap, HashSet},
-    rc::Rc,
-};
+use std::{cell::RefCell, rc::Rc};
+
+// NOTE: This is the hash algorithm that mlua also uses, so we
+// are not adding any additional dependencies / bloat by using it.
+use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::{thread_id::ThreadId, util::ThreadResult};
 
 #[derive(Clone)]
 pub(crate) struct ThreadResultMap {
-    tracked: Rc<RefCell<HashSet<ThreadId>>>,
-    inner: Rc<RefCell<HashMap<ThreadId, ThreadResult>>>,
+    tracked: Rc<RefCell<FxHashSet<ThreadId>>>,
+    inner: Rc<RefCell<FxHashMap<ThreadId, ThreadResult>>>,
 }
 
 impl ThreadResultMap {
     pub fn new() -> Self {
         Self {
-            tracked: Rc::new(RefCell::new(HashSet::new())),
-            inner: Rc::new(RefCell::new(HashMap::new())),
+            tracked: Rc::new(RefCell::new(FxHashSet::default())),
+            inner: Rc::new(RefCell::new(FxHashMap::default())),
         }
     }