From 177864be60c08cb61fd577eb99ee5c99481fc03e Mon Sep 17 00:00:00 2001
From: mat <git@matdoes.dev>
Date: Thu, 5 Oct 2023 01:40:25 -0500
Subject: [PATCH] replace a linear search with a binary search . . .

---
 Cargo.lock                         |  1 +
 azalea-core/src/position.rs        |  8 ++++----
 azalea/Cargo.toml                  |  1 +
 azalea/src/pathfinder/astar.rs     |  6 +++---
 azalea/src/pathfinder/moves/mod.rs | 11 +++++++++--
 5 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index afaf31ee5..9bea5504f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -193,6 +193,7 @@ dependencies = [
  "parking_lot",
  "priority-queue",
  "rand",
+ "rustc-hash",
  "thiserror",
  "tokio",
  "uuid",
diff --git a/azalea-core/src/position.rs b/azalea-core/src/position.rs
index f6bc4157a..540419ba3 100755
--- a/azalea-core/src/position.rs
+++ b/azalea-core/src/position.rs
@@ -246,7 +246,7 @@ impl Hash for ChunkPos {
 impl nohash_hasher::IsEnabled for ChunkPos {}
 
 /// The coordinates of a chunk section in the world.
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
 pub struct ChunkSectionPos {
     pub x: i32,
     pub y: i32,
@@ -413,9 +413,9 @@ impl From<BlockPos> for ChunkSectionBlockPos {
     #[inline]
     fn from(pos: BlockPos) -> Self {
         ChunkSectionBlockPos {
-            x: pos.x as u8 & 0xF,
-            y: pos.y as u8 & 0xF,
-            z: pos.z as u8 & 0xF,
+            x: (pos.x & 0xF) as u8,
+            y: (pos.y & 0xF) as u8,
+            z: (pos.z & 0xF) as u8,
         }
     }
 }
diff --git a/azalea/Cargo.toml b/azalea/Cargo.toml
index cecd316b1..0b8eca120 100644
--- a/azalea/Cargo.toml
+++ b/azalea/Cargo.toml
@@ -42,6 +42,7 @@ uuid = "1.4.1"
 bevy_log = "0.11.3"
 azalea-entity = { version = "0.8.0", path = "../azalea-entity" }
 bevy_time = "0.11.3"
+rustc-hash = "1.1.0"
 
 [dev-dependencies]
 criterion = "0.5.1"
diff --git a/azalea/src/pathfinder/astar.rs b/azalea/src/pathfinder/astar.rs
index 4e1d10393..98525e03b 100644
--- a/azalea/src/pathfinder/astar.rs
+++ b/azalea/src/pathfinder/astar.rs
@@ -1,6 +1,5 @@
 use std::{
     cmp::Reverse,
-    collections::HashMap,
     fmt::Debug,
     hash::Hash,
     time::{Duration, Instant},
@@ -8,6 +7,7 @@ use std::{
 
 use log::{debug, trace, warn};
 use priority_queue::PriorityQueue;
+use rustc_hash::FxHashMap;
 
 pub struct Path<P, M>
 where
@@ -40,7 +40,7 @@ where
 
     let mut open_set = PriorityQueue::new();
     open_set.push(start, Reverse(Weight(0.)));
-    let mut nodes: HashMap<P, Node<P, M>> = HashMap::new();
+    let mut nodes: FxHashMap<P, Node<P, M>> = FxHashMap::default();
     nodes.insert(
         start,
         Node {
@@ -134,7 +134,7 @@ where
     best_paths[0]
 }
 
-fn reconstruct_path<P, M>(mut nodes: HashMap<P, Node<P, M>>, current: P) -> Vec<Movement<P, M>>
+fn reconstruct_path<P, M>(mut nodes: FxHashMap<P, Node<P, M>>, current: P) -> Vec<Movement<P, M>>
 where
     P: Eq + Hash + Copy + Debug,
 {
diff --git a/azalea/src/pathfinder/moves/mod.rs b/azalea/src/pathfinder/moves/mod.rs
index f65e556ff..49615a3aa 100644
--- a/azalea/src/pathfinder/moves/mod.rs
+++ b/azalea/src/pathfinder/moves/mod.rs
@@ -58,6 +58,7 @@ pub struct PathfinderCtx {
 #[derive(Default)]
 pub struct CachedSections {
     pub last_index: usize,
+    pub second_last_index: usize,
     pub sections: Vec<CachedSection>,
 }
 
@@ -67,15 +68,20 @@ impl CachedSections {
         if let Some(last_item) = self.sections.get(self.last_index) {
             if last_item.pos == pos {
                 return Some(&mut self.sections[self.last_index]);
+            } else if let Some(second_last_item) = self.sections.get(self.second_last_index) {
+                if second_last_item.pos == pos {
+                    return Some(&mut self.sections[self.second_last_index]);
+                }
             }
         }
 
         let index = self
             .sections
-            .iter_mut()
-            .position(|section| section.pos == pos);
+            .binary_search_by(|section| section.pos.cmp(&pos))
+            .ok();
 
         if let Some(index) = index {
+            self.second_last_index = self.last_index;
             self.last_index = index;
             return Some(&mut self.sections[index]);
         }
@@ -85,6 +91,7 @@ impl CachedSections {
     #[inline]
     pub fn insert(&mut self, section: CachedSection) {
         self.sections.push(section);
+        self.sections.sort_unstable_by(|a, b| a.pos.cmp(&b.pos));
     }
 }