tracing capture interface

Signed-off-by: Jason Volk <jason@zemos.net>

src/core/log/capture/util.rs

@@ -0,0 +1,19 @@
+use std::sync::{Arc, Mutex};
+
+use super::{super::fmt, Closure};
+
+pub fn to_html<S>(out: &Arc<Mutex<S>>) -> Box<Closure>
+where
+	S: std::fmt::Write + Send + 'static,
+{
+	let out = out.clone();
+	Box::new(move |data| {
+		fmt::html(
+			&mut *out.lock().expect("locked"),
+			&data.level(),
+			data.span_name(),
+			data.message(),
+		)
+		.expect("log line appended");
+	})
+}