From aacc35e4afedd52e5b0bfa581426fa5ce38a78ea Mon Sep 17 00:00:00 2001
From: Andrew <andrew@sidekick.team>
Date: Tue, 8 Nov 2022 17:00:15 +1300
Subject: [PATCH] Use FxHasher in color to palette

---
 src/reduction/color.rs | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/reduction/color.rs b/src/reduction/color.rs
index 078b01c7..5284c94e 100644
--- a/src/reduction/color.rs
+++ b/src/reduction/color.rs
@@ -4,7 +4,10 @@ use crate::png::PngImage;
 use indexmap::IndexMap;
 use itertools::Itertools;
 use rgb::{FromSlice, RGB8, RGBA8};
-use std::hash::Hash;
+use rustc_hash::FxHasher;
+use std::hash::{BuildHasherDefault, Hash};
+
+type FxIndexMap<K, V> = IndexMap<K, V, BuildHasherDefault<FxHasher>>;
 
 #[must_use]
 pub fn reduce_rgba_to_grayscale_alpha(png: &PngImage) -> Option<PngImage> {
@@ -78,7 +81,7 @@ pub fn reduce_rgba_to_grayscale_alpha(png: &PngImage) -> Option<PngImage> {
 
 fn reduce_scanline_to_palette<T>(
     iter: impl IntoIterator<Item = T>,
-    palette: &mut IndexMap<T, u8>,
+    palette: &mut FxIndexMap<T, u8>,
     reduced: &mut Vec<u8>,
 ) -> bool
 where
@@ -107,7 +110,8 @@ pub fn reduced_color_to_palette(png: &PngImage) -> Option<PngImage> {
         return None;
     }
     let mut raw_data = Vec::with_capacity(png.data.len());
-    let mut palette = IndexMap::with_capacity(257);
+    let mut palette = FxIndexMap::default();
+    palette.reserve(257);
     let transparency_pixel = png
         .transparency_pixel
         .as_ref()