client/beefy: deduplicate metrics registration code

client/beefy/src/communication/request_response/incoming_requests_handler.rs

@@ -35,7 +35,7 @@ use crate::{
 		BEEFY_SYNC_LOG_TARGET,
 	},
 	metric_inc,
-	metrics::OnDemandIncomingRequestsMetrics,
+	metrics::{register_metrics, OnDemandIncomingRequestsMetrics},
 };
 
 /// A request coming in, including a sender for sending responses.
@@ -143,27 +143,7 @@ where
 		let (request_receiver, config) =
 			on_demand_justifications_protocol_config(genesis_hash, fork_id);
 		let justif_protocol_name = config.name.clone();
-		let metrics = prometheus_registry
-			.as_ref()
-			.map(OnDemandIncomingRequestsMetrics::register)
-			.and_then(|result| match result {
-				Ok(metrics) => {
-					debug!(
-						target: "beefy",
-						"🥩 Registered on-demand incoming justification requests metrics"
-					);
-					Some(metrics)
-				},
-				Err(err) => {
-					debug!(
-						target: "beefy",
-						"🥩 Failed to register incoming justification requests metrics: {:?}",
-						err
-					);
-					None
-				},
-			});
-
+		let metrics = register_metrics(prometheus_registry);
 		(
 			Self { request_receiver, justif_protocol_name, client, metrics, _block: PhantomData },
 			config,

client/beefy/src/communication/request_response/outgoing_requests_engine.rs

@@ -35,7 +35,7 @@ use crate::{
 	communication::request_response::{Error, JustificationRequest, BEEFY_SYNC_LOG_TARGET},
 	justification::{decode_and_verify_finality_proof, BeefyVersionedFinalityProof},
 	metric_inc,
-	metrics::OnDemandOutgoingRequestsMetrics,
+	metrics::{register_metrics, OnDemandOutgoingRequestsMetrics},
 	KnownPeers,
 };
 
@@ -73,26 +73,7 @@ impl<B: Block> OnDemandJustificationsEngine<B> {
 		live_peers: Arc<Mutex<KnownPeers<B>>>,
 		prometheus_registry: Option<prometheus::Registry>,
 	) -> Self {
-		let metrics = prometheus_registry
-			.as_ref()
-			.map(OnDemandOutgoingRequestsMetrics::register)
-			.and_then(|result| match result {
-				Ok(metrics) => {
-					debug!(
-						target: "beefy",
-						"🥩 Registered on-demand outgoing justification requests metrics"
-					);
-					Some(metrics)
-				},
-				Err(err) => {
-					debug!(
-						target: "beefy",
-						"🥩 Failed to register outgoing justification requests metrics: {:?}",
-						err
-					);
-					None
-				},
-			});
+		let metrics = register_metrics(prometheus_registry);
 		Self {
 			network,
 			protocol_name,

client/beefy/src/lib.rs

@@ -28,6 +28,7 @@ use crate::{
 		},
 	},
 	import::BeefyBlockImport,
+	metrics::register_metrics,
 	round::Rounds,
 	worker::PersistedState,
 };
@@ -36,7 +37,7 @@ use beefy_primitives::{
 	GENESIS_AUTHORITY_SET_ID,
 };
 use futures::{stream::Fuse, StreamExt};
-use log::{debug, error, info};
+use log::{error, info};
 use parking_lot::Mutex;
 use prometheus::Registry;
 use sc_client_api::{Backend, BlockBackend, BlockchainEvents, FinalityNotifications, Finalizer};
@@ -153,20 +154,7 @@ where
 	// BlockImport -> Voter links
 	let (to_voter_justif_sender, from_block_import_justif_stream) =
 		BeefyVersionedFinalityProofStream::<B>::channel();
-
-	let metrics = prometheus_registry
-		.as_ref()
-		.map(metrics::BlockImportMetrics::register)
-		.and_then(|result| match result {
-			Ok(metrics) => {
-				debug!(target: "beefy", "🥩 Registered block-import metrics");
-				Some(metrics)
-			},
-			Err(err) => {
-				debug!(target: "beefy", "🥩 Failed to register block-import metrics: {:?}", err);
-				None
-			},
-		});
+	let metrics = register_metrics(prometheus_registry);
 
 	// BlockImport
 	let import = BeefyBlockImport::new(
@@ -262,21 +250,7 @@ where
 		gossip_validator.clone(),
 		None,
 	);
-
-	let metrics =
-		prometheus_registry
-			.as_ref()
-			.map(metrics::VoterMetrics::register)
-			.and_then(|result| match result {
-				Ok(metrics) => {
-					debug!(target: LOG_TARGET, "🥩 Registered voter metrics");
-					Some(metrics)
-				},
-				Err(err) => {
-					debug!(target: LOG_TARGET, "🥩 Failed to register voter metrics: {:?}", err);
-					None
-				},
-			});
+	let metrics = register_metrics(prometheus_registry.clone());
 
 	// The `GossipValidator` adds and removes known peers based on valid votes and network events.
 	let on_demand_justifications = OnDemandJustificationsEngine::new(

client/beefy/src/metrics.rs

@@ -18,8 +18,15 @@
 
 //! BEEFY Prometheus metrics definition
 
+use log::debug;
 use prometheus::{register, Counter, Gauge, PrometheusError, Registry, U64};
 
+/// Helper trait for registering BEEFY metrics to Prometheus registry.
+pub(crate) trait PrometheusRegister<T: Sized = Self>: Sized {
+	const DESCRIPTION: &'static str;
+	fn register(registry: &Registry) -> Result<Self, PrometheusError>;
+}
+
 /// BEEFY voting-related metrics exposed through Prometheus
 #[derive(Clone, Debug)]
 pub struct VoterMetrics {
@@ -59,8 +66,9 @@ pub struct VoterMetrics {
 	pub beefy_successful_handled_votes: Counter<U64>,
 }
 
-impl VoterMetrics {
-	pub(crate) fn register(registry: &Registry) -> Result<Self, PrometheusError> {
+impl PrometheusRegister for VoterMetrics {
+	const DESCRIPTION: &'static str = "voter";
+	fn register(registry: &Registry) -> Result<Self, PrometheusError> {
 		Ok(Self {
 			beefy_validator_set_id: register(
 				Gauge::new(
@@ -179,8 +187,9 @@ pub struct BlockImportMetrics {
 	pub beefy_bad_justification_imports: Counter<U64>,
 }
 
-impl BlockImportMetrics {
-	pub(crate) fn register(registry: &Registry) -> Result<Self, PrometheusError> {
+impl PrometheusRegister for BlockImportMetrics {
+	const DESCRIPTION: &'static str = "block-import";
+	fn register(registry: &Registry) -> Result<Self, PrometheusError> {
 		Ok(Self {
 			beefy_good_justification_imports: register(
 				Counter::new(
@@ -209,8 +218,9 @@ pub struct OnDemandIncomingRequestsMetrics {
 	pub beefy_failed_justification_responses: Counter<U64>,
 }
 
-impl OnDemandIncomingRequestsMetrics {
-	pub(crate) fn register(registry: &Registry) -> Result<Self, PrometheusError> {
+impl PrometheusRegister for OnDemandIncomingRequestsMetrics {
+	const DESCRIPTION: &'static str = "on-demand incoming justification requests";
+	fn register(registry: &Registry) -> Result<Self, PrometheusError> {
 		Ok(Self {
 			beefy_successful_justification_responses: register(
 				Counter::new(
@@ -245,8 +255,9 @@ pub struct OnDemandOutgoingRequestsMetrics {
 	pub beefy_on_demand_justification_good_proof: Counter<U64>,
 }
 
-impl OnDemandOutgoingRequestsMetrics {
-	pub(crate) fn register(registry: &Registry) -> Result<Self, PrometheusError> {
+impl PrometheusRegister for OnDemandOutgoingRequestsMetrics {
+	const DESCRIPTION: &'static str = "on-demand outgoing justification requests";
+	fn register(registry: &Registry) -> Result<Self, PrometheusError> {
 		Ok(Self {
 			beefy_on_demand_justification_no_peer_to_request_from: register(
 				Counter::new(
@@ -287,6 +298,21 @@ impl OnDemandOutgoingRequestsMetrics {
 	}
 }
 
+pub(crate) fn register_metrics<T: PrometheusRegister>(
+	prometheus_registry: Option<prometheus::Registry>,
+) -> Option<T> {
+	prometheus_registry.as_ref().map(T::register).and_then(|result| match result {
+		Ok(metrics) => {
+			debug!(target: "beefy", "🥩 Registered {} metrics", T::DESCRIPTION);
+			Some(metrics)
+		},
+		Err(err) => {
+			debug!(target: "beefy", "🥩 Failed to register {} metrics: {:?}", T::DESCRIPTION, err);
+			None
+		},
+	})
+}
+
 // Note: we use the `format` macro to convert an expr into a `u64`. This will fail,
 // if expr does not derive `Display`.
 #[macro_export]