tokio-xmpp: Improve highlight_xml()

Emmanuel Gil Peyrot created 1 year ago

First switch to LazyLock from OnceLock, to simplify the code.

Then concatenate the colour reset escape code instead of using
format!(), since the vast majority of those strings have more capacity
than their length it will avoid a reallocation in most cases.

Change summary

tokio-xmpp/src/xmlstream/mod.rs | 30 +++++++++++++++---------------
1 file changed, 15 insertions(+), 15 deletions(-)

Detailed changes

tokio-xmpp/src/xmlstream/mod.rs

@@ -62,7 +62,7 @@ use core::pin::Pin;
 use core::task::{Context, Poll};
 use std::io;
 #[cfg(feature = "syntax-highlighting")]
-use std::sync::OnceLock;
+use std::sync::LazyLock;
 
 use futures::{ready, Sink, SinkExt, Stream};
 
@@ -85,25 +85,25 @@ pub use self::responder::{AcceptedStream, PendingFeaturesSend};
 pub use self::xmpp::XmppStreamElement;
 
 #[cfg(feature = "syntax-highlighting")]
-static PS: OnceLock<syntect::parsing::SyntaxSet> = OnceLock::new();
+static PS: LazyLock<syntect::parsing::SyntaxSet> =
+    LazyLock::new(syntect::parsing::SyntaxSet::load_defaults_newlines);
+
 #[cfg(feature = "syntax-highlighting")]
-static SYNTAX: OnceLock<syntect::parsing::SyntaxReference> = OnceLock::new();
+static SYNTAX: LazyLock<&syntect::parsing::SyntaxReference> =
+    LazyLock::new(|| PS.find_syntax_by_extension("xml").unwrap());
+
 #[cfg(feature = "syntax-highlighting")]
-static THEME: OnceLock<syntect::highlighting::Theme> = OnceLock::new();
+static THEME: LazyLock<syntect::highlighting::Theme> = LazyLock::new(|| {
+    syntect::highlighting::ThemeSet::load_defaults().themes["Solarized (dark)"].clone()
+});
 
 #[cfg(feature = "syntax-highlighting")]
 fn highlight_xml(xml: &str) -> String {
-    let ps = PS.get_or_init(syntect::parsing::SyntaxSet::load_defaults_newlines);
-    let mut h = syntect::easy::HighlightLines::new(
-        SYNTAX.get_or_init(|| ps.find_syntax_by_extension("xml").unwrap().clone()),
-        THEME.get_or_init(|| {
-            syntect::highlighting::ThemeSet::load_defaults().themes["Solarized (dark)"].clone()
-        }),
-    );
-
-    let ranges: Vec<_> = h.highlight_line(&xml, ps).unwrap();
-    let escaped = syntect::util::as_24_bit_terminal_escaped(&ranges[..], false);
-    format!("{}\x1b[0m", escaped)
+    let mut h = syntect::easy::HighlightLines::new(&SYNTAX, &THEME);
+    let ranges: Vec<_> = h.highlight_line(&xml, &PS).unwrap();
+    let mut escaped = syntect::util::as_24_bit_terminal_escaped(&ranges[..], false);
+    escaped += "\x1b[0m";
+    escaped
 }
 
 struct LogXsoBuf<'x>(&'x [u8]);