From 533f7959f785f9af0a7ef1a668a3c0a1ecd9080e Mon Sep 17 00:00:00 2001
From: Dmitry Dygalo <dmitry@dygalo.dev>
Date: Tue, 11 Mar 2025 15:46:57 +0100
Subject: [PATCH] perf: Slightly improve performance of HTML serialization

Signed-off-by: Dmitry Dygalo <dmitry@dygalo.dev>
---
 CHANGELOG.md                      |  4 ++++
 css-inline/src/html/serializer.rs | 12 ++++++------
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5a277b18..7bfba9bb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Performance
+
+- Slightly improve performance of HTML serialization.
+
 ## [0.14.4] - 2024-12-27
 
 ### Changed
diff --git a/css-inline/src/html/serializer.rs b/css-inline/src/html/serializer.rs
index 20a26b13..477bff57 100644
--- a/css-inline/src/html/serializer.rs
+++ b/css-inline/src/html/serializer.rs
@@ -171,12 +171,12 @@ impl<'a, W: Write> HtmlSerializer<'a, W> {
                     .expect("Invalid substring")
                     .as_bytes(),
             )?;
-            match part {
-                "&" => self.writer.write_all(b"&amp;")?,
-                "\u{00A0}" => self.writer.write_all(b"&nbsp;")?,
-                "<" => self.writer.write_all(b"&lt;")?,
-                ">" => self.writer.write_all(b"&gt;")?,
-                _ => unreachable!("Only the variants above are searched"),
+            match (part.as_bytes()[0] & 0b0000_1110) >> 1 {
+                1 => self.writer.write_all(b"&nbsp;")?,
+                3 => self.writer.write_all(b"&amp;")?,
+                6 => self.writer.write_all(b"&lt;")?,
+                7 => self.writer.write_all(b"&gt;")?,
+                _ => unreachable!(),
             };
             last_end = start.checked_add(part.len()).expect("Size overflow");
         }