support reloading config via SIGUSR1

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

src/service/config/mod.rs

@@ -0,0 +1,55 @@
+use std::{iter, path::Path, sync::Arc};
+
+use async_trait::async_trait;
+use conduwuit::{
+	config::{check, Config},
+	error, implement, Result, Server,
+};
+
+pub struct Service {
+	server: Arc<Server>,
+}
+
+const SIGNAL: &str = "SIGUSR1";
+
+#[async_trait]
+impl crate::Service for Service {
+	fn build(args: crate::Args<'_>) -> Result<Arc<Self>> {
+		Ok(Arc::new(Self { server: args.server.clone() }))
+	}
+
+	async fn worker(self: Arc<Self>) -> Result {
+		while self.server.running() {
+			if self.server.signal.subscribe().recv().await == Ok(SIGNAL) {
+				if let Err(e) = self.handle_reload() {
+					error!("Failed to reload config: {e}");
+				}
+			}
+		}
+
+		Ok(())
+	}
+
+	fn name(&self) -> &str { crate::service::make_name(std::module_path!()) }
+}
+
+#[implement(Service)]
+fn handle_reload(&self) -> Result {
+	if self.server.config.config_reload_signal {
+		self.reload(iter::empty())?;
+	}
+
+	Ok(())
+}
+
+#[implement(Service)]
+pub fn reload<'a, I>(&self, paths: I) -> Result<Arc<Config>>
+where
+	I: Iterator<Item = &'a Path>,
+{
+	let old = self.server.config.clone();
+	let new = Config::load(paths).and_then(|raw| Config::new(&raw))?;
+
+	check::reload(&old, &new)?;
+	self.server.config.update(new)
+}