Flatten back the structure (#837)

* Remove chains.

* Move relay clients.

* Flatten generic.

* Fix fmt.

bridges/relays/messages/src/metrics.rs

@@ -0,0 +1,107 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity Bridges Common is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Metrics for message lane relay loop.
+
+use crate::message_lane::MessageLane;
+use crate::message_lane_loop::{SourceClientState, TargetClientState};
+
+use bp_messages::MessageNonce;
+use relay_utils::metrics::{register, GaugeVec, Metrics, Opts, Registry, U64};
+
+/// Message lane relay metrics.
+///
+/// Cloning only clones references.
+#[derive(Clone)]
+pub struct MessageLaneLoopMetrics {
+	/// Best finalized block numbers - "source", "target", "source_at_target", "target_at_source".
+	best_block_numbers: GaugeVec<U64>,
+	/// Lane state nonces: "source_latest_generated", "source_latest_confirmed",
+	/// "target_latest_received", "target_latest_confirmed".
+	lane_state_nonces: GaugeVec<U64>,
+}
+
+impl Metrics for MessageLaneLoopMetrics {
+	fn register(&self, registry: &Registry) -> Result<(), String> {
+		register(self.best_block_numbers.clone(), registry).map_err(|e| e.to_string())?;
+		register(self.lane_state_nonces.clone(), registry).map_err(|e| e.to_string())?;
+		Ok(())
+	}
+}
+
+impl Default for MessageLaneLoopMetrics {
+	fn default() -> Self {
+		MessageLaneLoopMetrics {
+			best_block_numbers: GaugeVec::new(
+				Opts::new("best_block_numbers", "Best finalized block numbers"),
+				&["type"],
+			)
+			.expect("metric is static and thus valid; qed"),
+			lane_state_nonces: GaugeVec::new(Opts::new("lane_state_nonces", "Nonces of the lane state"), &["type"])
+				.expect("metric is static and thus valid; qed"),
+		}
+	}
+}
+
+impl MessageLaneLoopMetrics {
+	/// Update source client state metrics.
+	pub fn update_source_state<P: MessageLane>(&self, source_client_state: SourceClientState<P>) {
+		self.best_block_numbers
+			.with_label_values(&["source"])
+			.set(source_client_state.best_self.0.into());
+		self.best_block_numbers
+			.with_label_values(&["target_at_source"])
+			.set(source_client_state.best_finalized_peer_at_best_self.0.into());
+	}
+
+	/// Update target client state metrics.
+	pub fn update_target_state<P: MessageLane>(&self, target_client_state: TargetClientState<P>) {
+		self.best_block_numbers
+			.with_label_values(&["target"])
+			.set(target_client_state.best_self.0.into());
+		self.best_block_numbers
+			.with_label_values(&["source_at_target"])
+			.set(target_client_state.best_finalized_peer_at_best_self.0.into());
+	}
+
+	/// Update latest generated nonce at source.
+	pub fn update_source_latest_generated_nonce<P: MessageLane>(&self, source_latest_generated_nonce: MessageNonce) {
+		self.lane_state_nonces
+			.with_label_values(&["source_latest_generated"])
+			.set(source_latest_generated_nonce);
+	}
+
+	/// Update latest confirmed nonce at source.
+	pub fn update_source_latest_confirmed_nonce<P: MessageLane>(&self, source_latest_confirmed_nonce: MessageNonce) {
+		self.lane_state_nonces
+			.with_label_values(&["source_latest_confirmed"])
+			.set(source_latest_confirmed_nonce);
+	}
+
+	/// Update latest received nonce at target.
+	pub fn update_target_latest_received_nonce<P: MessageLane>(&self, target_latest_generated_nonce: MessageNonce) {
+		self.lane_state_nonces
+			.with_label_values(&["target_latest_received"])
+			.set(target_latest_generated_nonce);
+	}
+
+	/// Update latest confirmed nonce at target.
+	pub fn update_target_latest_confirmed_nonce<P: MessageLane>(&self, target_latest_confirmed_nonce: MessageNonce) {
+		self.lane_state_nonces
+			.with_label_values(&["target_latest_confirmed"])
+			.set(target_latest_confirmed_nonce);
+	}
+}