refactor overseer into proc-macro based pattern (#2962)

polkadot/node/overseer/overseer-gen/examples/dummy.rs

@@ -0,0 +1,134 @@
+//! A dummy to be used with cargo expand
+
+use polkadot_overseer_gen::*;
+use polkadot_node_network_protocol::WrongVariant;
+
+
+/// Concrete subsystem implementation for `MsgStrukt` msg type.
+#[derive(Default)]
+pub struct AwesomeSubSys;
+
+impl ::polkadot_overseer_gen::Subsystem<XxxSubsystemContext<MsgStrukt>, Yikes> for  AwesomeSubSys {
+	fn start(self, _ctx: XxxSubsystemContext<MsgStrukt>) -> SpawnedSubsystem < Yikes > {
+		unimplemented!("starting yay!")
+	}
+}
+
+#[derive(Default)]
+pub struct GoblinTower;
+
+impl ::polkadot_overseer_gen::Subsystem<XxxSubsystemContext<Plinko>, Yikes> for GoblinTower {
+	fn start(self, _ctx: XxxSubsystemContext<Plinko>) -> SpawnedSubsystem < Yikes > {
+		unimplemented!("welcum")
+	}
+}
+
+
+/// A signal sent by the overseer.
+#[derive(Debug, Clone)]
+pub struct SigSigSig;
+
+
+/// The external event.
+#[derive(Debug, Clone)]
+pub struct EvX;
+
+
+impl EvX {
+	pub fn focus<'a, T>(&'a self) -> Result<EvX, ()> {
+		unimplemented!("dispatch")
+	}
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct Yikes;
+
+impl std::fmt::Display for Yikes {
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+		writeln!(f, "yikes!")
+	}
+}
+
+impl std::error::Error for Yikes {}
+
+impl From<polkadot_overseer_gen::OverseerError> for Yikes {
+	fn from(_: polkadot_overseer_gen::OverseerError) -> Yikes {
+		Yikes
+	}
+}
+
+impl From<polkadot_overseer_gen::mpsc::SendError> for Yikes {
+	fn from(_: polkadot_overseer_gen::mpsc::SendError) -> Yikes {
+		Yikes
+	}
+}
+
+#[derive(Debug, Clone)]
+pub struct MsgStrukt(u8);
+
+#[derive(Debug, Clone, Copy)]
+pub struct Plinko;
+
+impl From<NetworkMsg> for MsgStrukt {
+	fn from(_event: NetworkMsg) -> Self {
+		MsgStrukt(1u8)
+	}
+}
+
+
+#[derive(Debug, Clone, Copy)]
+pub enum NetworkMsg {
+	A,
+	B,
+	C,
+}
+
+
+impl NetworkMsg {
+	fn focus(&self) -> Result<Self, WrongVariant> {
+		Ok(match self {
+			Self::B => return Err(WrongVariant),
+			Self::A | Self::C => self.clone()
+		})
+	}
+}
+
+
+
+#[overlord(signal=SigSigSig, event=EvX, error=Yikes, network=NetworkMsg, gen=AllMessages)]
+struct Xxx {
+	#[subsystem(MsgStrukt)]
+	sub0: AwesomeSubSys,
+
+	#[subsystem(no_dispatch, blocking, Plinko)]
+	plinkos: GoblinTower,
+
+	i_like_pi: f64,
+}
+
+#[derive(Debug, Clone)]
+struct DummySpawner;
+
+impl SpawnNamed for DummySpawner{
+	fn spawn_blocking(&self, name: &'static str, _future: futures::future::BoxFuture<'static, ()>) {
+		unimplemented!("spawn blocking {}", name)
+	}
+
+	fn spawn(&self, name: &'static str, _future: futures::future::BoxFuture<'static, ()>) {
+		unimplemented!("spawn {}", name)
+	}
+}
+
+#[derive(Debug, Clone)]
+struct DummyCtx;
+
+fn main() {
+	let (overseer, _handler): (Xxx<_>, _) = Xxx::builder()
+		.sub0(AwesomeSubSys::default())
+		.plinkos(GoblinTower::default())
+		.i_like_pi(::std::f64::consts::PI)
+		.spawner(DummySpawner)
+		.build()
+		.unwrap();
+	assert_eq!(overseer.i_like_pi.floor() as i8, 3);
+}