tracing capture interface

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

src/core/log/capture/data.rs

@@ -0,0 +1,31 @@
+use tracing::Level;
+use tracing_core::{span::Current, Event};
+
+use super::layer::Value;
+
+pub struct Data<'a> {
+	pub event: &'a Event<'a>,
+	pub current: &'a Current,
+	pub values: Option<&'a mut [Value]>,
+}
+
+impl Data<'_> {
+	#[must_use]
+	pub fn level(&self) -> Level { *self.event.metadata().level() }
+
+	#[must_use]
+	pub fn mod_name(&self) -> &str { self.event.metadata().module_path().unwrap_or_default() }
+
+	#[must_use]
+	pub fn span_name(&self) -> &str { self.current.metadata().map_or("", |s| s.name()) }
+
+	#[must_use]
+	pub fn message(&self) -> &str {
+		self.values
+			.as_ref()
+			.expect("values are not composed for a filter")
+			.iter()
+			.find(|(k, _)| *k == "message")
+			.map_or("", |(_, v)| v.as_str())
+	}
+}