tracing capture interface

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

src/core/log/capture/state.rs

@@ -0,0 +1,35 @@
+use std::sync::{Arc, RwLock};
+
+use super::Capture;
+
+/// Capture layer state.
+pub struct State {
+	pub(super) active: RwLock<Vec<Arc<Capture>>>,
+}
+
+impl Default for State {
+	fn default() -> Self { Self::new() }
+}
+
+impl State {
+	#[must_use]
+	pub fn new() -> Self {
+		Self {
+			active: RwLock::new(Vec::new()),
+		}
+	}
+
+	pub(super) fn add(&self, capture: &Arc<Capture>) {
+		self.active
+			.write()
+			.expect("locked for writing")
+			.push(capture.clone());
+	}
+
+	pub(super) fn del(&self, capture: &Arc<Capture>) {
+		let mut vec = self.active.write().expect("locked for writing");
+		if let Some(pos) = vec.iter().position(|v| Arc::ptr_eq(v, capture)) {
+			vec.swap_remove(pos);
+		}
+	}
+}