perf: Use memchr for writing declaration values

Signed-off-by: Dmitry Dygalo <dmitry@dygalo.dev>

Author: Stranger6667

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Performance
+
+- Faster HTML serialization for styles containing double quotes.
+
 ## [0.19.1] - 2026-01-23
 
 ### Changed

bindings/c/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Performance
+
+- Faster HTML serialization for styles containing double quotes.
+
 ## [0.19.1] - 2026-01-23
 
 ### Changed

bindings/java/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Performance
+
+- Faster HTML serialization for styles containing double quotes.
+
 ## [0.19.1] - 2026-01-23
 
 ### Changed

bindings/javascript/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Performance
+
+- Faster HTML serialization for styles containing double quotes.
+
 ## [0.19.2] - 2026-01-23
 
 ### Changed

bindings/php/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Performance
+
+- Faster HTML serialization for styles containing double quotes.
+
 ## [0.19.1] - 2026-01-23
 
 ### Changed

bindings/python/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Performance
+
+- Faster HTML serialization for styles containing double quotes.
+
 ## [0.19.1] - 2026-01-23
 
 ### Changed

bindings/ruby/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Performance
+
+- Faster HTML serialization for styles containing double quotes.
+
 ## [0.19.1] - 2026-01-23
 
 ### Changed

css-inline/Cargo.toml

@@ -32,6 +32,7 @@ stylesheet-cache = ["lru"]
 cssparser = "0.36.0"
 html5ever = "0.38.0"
 lru = { version = "0.16.0", optional = true }
+memchr = "2.7"
 precomputed-hash = "0.1.1"
 rayon = { version = "1.10", optional = true }
 reqwest = { version = "0.12.0", optional = true, default-features = false, features = ["rustls-tls", "blocking"] }

css-inline/src/html/serializer.rs

@@ -6,6 +6,7 @@ use super::{
 };
 use crate::{html::ElementStyleMap, parser, InlineError};
 use html5ever::{local_name, ns, tendril::StrTendril, LocalName, QualName};
+use memchr::memchr_iter;
 use smallvec::{smallvec, SmallVec};
 use std::io::Write;
 
@@ -459,26 +460,18 @@ fn write_declaration<Wr: Write>(
 }
 
 #[inline]
+#[allow(clippy::arithmetic_side_effects)]
 fn write_declaration_value<Wr: Write>(writer: &mut Wr, value: &str) -> Result<(), InlineError> {
     let value = value.trim();
-    // Roughly based on `str::replace`
+    let bytes = value.as_bytes();
+
     let mut last_end = 0;
-    for (start, part) in value.match_indices('"') {
-        writer.write_all(
-            value
-                .get(last_end..start)
-                .expect("Invalid substring")
-                .as_bytes(),
-        )?;
+    for idx in memchr_iter(b'"', bytes) {
+        writer.write_all(&bytes[last_end..idx])?;
         writer.write_all(b"'")?;
-        last_end = start.checked_add(part.len()).expect("Size overflow");
+        last_end = idx + 1;
     }
-    writer.write_all(
-        value
-            .get(last_end..value.len())
-            .expect("Invalid substring")
-            .as_bytes(),
-    )?;
+    writer.write_all(&bytes[last_end..])?;
     Ok(())
 }