Flatten back the structure (#837)

* Remove chains.

* Move relay clients.

* Flatten generic.

* Fix fmt.

bridges/relays/headers/src/sync_loop_metrics.rs

@@ -0,0 +1,105 @@
+// 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 headers synchronization relay loop.
+
+use crate::sync::HeadersSync;
+use crate::sync_types::{HeaderStatus, HeadersSyncPipeline};
+
+use num_traits::Zero;
+use relay_utils::metrics::{register, GaugeVec, Metrics, Opts, Registry, U64};
+
+/// Headers sync metrics.
+#[derive(Clone)]
+pub struct SyncLoopMetrics {
+	/// Best syncing headers at "source" and "target" nodes.
+	best_block_numbers: GaugeVec<U64>,
+	/// Number of headers in given states (see `HeaderStatus`).
+	blocks_in_state: GaugeVec<U64>,
+}
+
+impl Metrics for SyncLoopMetrics {
+	fn register(&self, registry: &Registry) -> Result<(), String> {
+		register(self.best_block_numbers.clone(), registry).map_err(|e| e.to_string())?;
+		register(self.blocks_in_state.clone(), registry).map_err(|e| e.to_string())?;
+		Ok(())
+	}
+}
+
+impl Default for SyncLoopMetrics {
+	fn default() -> Self {
+		SyncLoopMetrics {
+			best_block_numbers: GaugeVec::new(
+				Opts::new("best_block_numbers", "Best block numbers on source and target nodes"),
+				&["node"],
+			)
+			.expect("metric is static and thus valid; qed"),
+			blocks_in_state: GaugeVec::new(
+				Opts::new("blocks_in_state", "Number of blocks in given state"),
+				&["state"],
+			)
+			.expect("metric is static and thus valid; qed"),
+		}
+	}
+}
+
+impl SyncLoopMetrics {
+	/// Update best block number at source.
+	pub fn update_best_block_at_source<Number: Into<u64>>(&self, source_best_number: Number) {
+		self.best_block_numbers
+			.with_label_values(&["source"])
+			.set(source_best_number.into());
+	}
+
+	/// Update best block number at target.
+	pub fn update_best_block_at_target<Number: Into<u64>>(&self, target_best_number: Number) {
+		self.best_block_numbers
+			.with_label_values(&["target"])
+			.set(target_best_number.into());
+	}
+
+	/// Update metrics.
+	pub fn update<P: HeadersSyncPipeline>(&self, sync: &HeadersSync<P>) {
+		let headers = sync.headers();
+		let source_best_number = sync.source_best_number().unwrap_or_else(Zero::zero);
+		let target_best_number = sync.target_best_header().map(|id| id.0).unwrap_or_else(Zero::zero);
+
+		self.update_best_block_at_source(source_best_number);
+		self.update_best_block_at_target(target_best_number);
+
+		self.blocks_in_state
+			.with_label_values(&["maybe_orphan"])
+			.set(headers.headers_in_status(HeaderStatus::MaybeOrphan) as _);
+		self.blocks_in_state
+			.with_label_values(&["orphan"])
+			.set(headers.headers_in_status(HeaderStatus::Orphan) as _);
+		self.blocks_in_state
+			.with_label_values(&["maybe_extra"])
+			.set(headers.headers_in_status(HeaderStatus::MaybeExtra) as _);
+		self.blocks_in_state
+			.with_label_values(&["extra"])
+			.set(headers.headers_in_status(HeaderStatus::Extra) as _);
+		self.blocks_in_state
+			.with_label_values(&["ready"])
+			.set(headers.headers_in_status(HeaderStatus::Ready) as _);
+		self.blocks_in_state
+			.with_label_values(&["incomplete"])
+			.set(headers.headers_in_status(HeaderStatus::Incomplete) as _);
+		self.blocks_in_state
+			.with_label_values(&["submitted"])
+			.set(headers.headers_in_status(HeaderStatus::Submitted) as _);
+	}
+}