From 70ac6421b1184602a700cc02bb6d4d3cd95d4cec Mon Sep 17 00:00:00 2001
From: Philipp Mildenberger <philipp@mildenberger.me>
Date: Sat, 7 Dec 2024 17:23:51 +0100
Subject: [PATCH] tree_arena: Use `hashbrown::HashMap` as drop-in replacement
 to optimize tree-access

---
 Cargo.lock                          | 3 +++
 Cargo.toml                          | 1 +
 tree_arena/Cargo.toml               | 1 +
 tree_arena/src/tree_arena_safe.rs   | 2 +-
 tree_arena/src/tree_arena_unsafe.rs | 3 ++-
 5 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index df4f1f562..eb16dc5d2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3722,6 +3722,9 @@ dependencies = [
 [[package]]
 name = "tree_arena"
 version = "0.1.0"
+dependencies = [
+ "hashbrown 0.15.2",
+]
 
 [[package]]
 name = "try-lock"
diff --git a/Cargo.toml b/Cargo.toml
index 93e3c5494..44077475e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -117,6 +117,7 @@ peniko = "0.2.0"
 winit = "0.30.4"
 tracing = { version = "0.1.40", default-features = false }
 smallvec = "1.13.2"
+hashbrown = "0.15.2"
 dpi = "0.1.1"
 image = { version = "0.25.2", default-features = false }
 web-time = "1.1.0"
diff --git a/tree_arena/Cargo.toml b/tree_arena/Cargo.toml
index 1b3fd0a4c..3b879ddd8 100644
--- a/tree_arena/Cargo.toml
+++ b/tree_arena/Cargo.toml
@@ -21,6 +21,7 @@ targets = []
 
 
 [dependencies]
+hashbrown.workspace = true
 
 [features]
 # This crate contains two implementations of a tree for use in masonry, one safe and the other unsafe.
diff --git a/tree_arena/src/tree_arena_safe.rs b/tree_arena/src/tree_arena_safe.rs
index dcdb6dd7f..aaa29c811 100644
--- a/tree_arena/src/tree_arena_safe.rs
+++ b/tree_arena/src/tree_arena_safe.rs
@@ -13,7 +13,7 @@
 
 use super::NodeId;
 
-use std::collections::HashMap;
+use hashbrown::HashMap;
 
 #[derive(Debug)]
 struct TreeNode<T> {
diff --git a/tree_arena/src/tree_arena_unsafe.rs b/tree_arena/src/tree_arena_unsafe.rs
index b3c71b271..b58d30b0f 100644
--- a/tree_arena/src/tree_arena_unsafe.rs
+++ b/tree_arena/src/tree_arena_unsafe.rs
@@ -5,7 +5,8 @@
 use super::NodeId;
 
 use std::cell::UnsafeCell;
-use std::collections::HashMap;
+
+use hashbrown::HashMap;
 
 #[derive(Debug)]
 struct TreeNode<T> {