Use custom type for ProtocolName (#12172)

* Add ProtocolName custom type

* Use new ProtocolName in sc_network_common

* Use new ProtocolName in sc_network

* Use new ProtocolName for BEEFY and GRANDPA

* Use new ProtocolName for notifications

* Use new ProtocolName in sc_network (part 2)

* Use new ProtocolName in sc_network_gossip

* Use new ProtocolName in sc_offchain

* Remove unused imports

* Some more fixes

* Add tests

* Fix minor import issues

* Re-export ProtocolName in sc_network

* Revert "Re-export ProtocolName in sc_network"

This reverts commit 8d8ff71927e7750757f29c9bbd88dc0ba181d214.

* Re-export ProtocolName in sc_network

* Remove dependency on sc-network-common from beefy-gadget

substrate/client/beefy/src/lib.rs

@@ -20,6 +20,7 @@ use beefy_primitives::{BeefyApi, MmrRootHash};
 use prometheus::Registry;
 use sc_client_api::{Backend, BlockchainEvents, Finalizer};
 use sc_consensus::BlockImport;
+use sc_network::ProtocolName;
 use sc_network_gossip::Network as GossipNetwork;
 use sp_api::ProvideRuntimeApi;
 use sp_blockchain::HeaderBackend;
@@ -55,6 +56,7 @@ pub use beefy_protocol_name::standard_name as protocol_standard_name;
 
 pub(crate) mod beefy_protocol_name {
 	use sc_chain_spec::ChainSpec;
+	use sc_network::ProtocolName;
 
 	const NAME: &str = "/beefy/1";
 	/// Old names for the notifications protocol, used for backward compatibility.
@@ -66,7 +68,7 @@ pub(crate) mod beefy_protocol_name {
 	pub fn standard_name<Hash: AsRef<[u8]>>(
 		genesis_hash: &Hash,
 		chain_spec: &Box<dyn ChainSpec>,
-	) -> std::borrow::Cow<'static, str> {
+	) -> ProtocolName {
 		let chain_prefix = match chain_spec.fork_id() {
 			Some(fork_id) => format!("/{}/{}", hex::encode(genesis_hash), fork_id),
 			None => format!("/{}", hex::encode(genesis_hash)),
@@ -79,7 +81,7 @@ pub(crate) mod beefy_protocol_name {
 /// [`sc_network::config::NetworkConfiguration::extra_sets`].
 /// For standard protocol name see [`beefy_protocol_name::standard_name`].
 pub fn beefy_peers_set_config(
-	protocol_name: std::borrow::Cow<'static, str>,
+	protocol_name: ProtocolName,
 ) -> sc_network::config::NonDefaultSetConfig {
 	let mut cfg = sc_network::config::NonDefaultSetConfig::new(protocol_name, 1024 * 1024);
 
@@ -202,7 +204,7 @@ where
 	/// Prometheus metric registry
 	pub prometheus_registry: Option<Registry>,
 	/// Chain specific GRANDPA protocol name. See [`beefy_protocol_name::standard_name`].
-	pub protocol_name: std::borrow::Cow<'static, str>,
+	pub protocol_name: ProtocolName,
 	/// Links between the block importer, the background voter and the RPC layer.
 	pub links: BeefyVoterLinks<B>,
 }

substrate/client/finality-grandpa/src/communication/mod.rs

@@ -70,6 +70,7 @@ pub(crate) mod tests;
 
 pub mod grandpa_protocol_name {
 	use sc_chain_spec::ChainSpec;
+	use sc_network_common::protocol::ProtocolName;
 
 	pub(crate) const NAME: &str = "/grandpa/1";
 	/// Old names for the notifications protocol, used for backward compatibility.
@@ -81,7 +82,7 @@ pub mod grandpa_protocol_name {
 	pub fn standard_name<Hash: AsRef<[u8]>>(
 		genesis_hash: &Hash,
 		chain_spec: &Box<dyn ChainSpec>,
-	) -> std::borrow::Cow<'static, str> {
+	) -> ProtocolName {
 		let chain_prefix = match chain_spec.fork_id() {
 			Some(fork_id) => format!("/{}/{}", hex::encode(genesis_hash), fork_id),
 			None => format!("/{}", hex::encode(genesis_hash)),

substrate/client/finality-grandpa/src/communication/tests.rs

@@ -28,7 +28,10 @@ use parity_scale_codec::Encode;
 use sc_network::{config::Role, Multiaddr, PeerId, ReputationChange};
 use sc_network_common::{
 	config::MultiaddrWithPeerId,
-	protocol::event::{Event as NetworkEvent, ObservedRole},
+	protocol::{
+		event::{Event as NetworkEvent, ObservedRole},
+		ProtocolName,
+	},
 	service::{
 		NetworkBlock, NetworkEventStream, NetworkNotification, NetworkPeers,
 		NetworkSyncForkRequest, NotificationSender, NotificationSenderError,
@@ -41,7 +44,6 @@ use sp_finality_grandpa::AuthorityList;
 use sp_keyring::Ed25519Keyring;
 use sp_runtime::traits::NumberFor;
 use std::{
-	borrow::Cow,
 	collections::HashSet,
 	pin::Pin,
 	sync::Arc,
@@ -78,7 +80,7 @@ impl NetworkPeers for TestNetwork {
 		let _ = self.sender.unbounded_send(Event::Report(who, cost_benefit));
 	}
 
-	fn disconnect_peer(&self, _who: PeerId, _protocol: Cow<'static, str>) {}
+	fn disconnect_peer(&self, _who: PeerId, _protocol: ProtocolName) {}
 
 	fn accept_unreserved_peers(&self) {
 		unimplemented!();
@@ -98,7 +100,7 @@ impl NetworkPeers for TestNetwork {
 
 	fn set_reserved_peers(
 		&self,
-		_protocol: Cow<'static, str>,
+		_protocol: ProtocolName,
 		_peers: HashSet<Multiaddr>,
 	) -> Result<(), String> {
 		unimplemented!();
@@ -106,23 +108,23 @@ impl NetworkPeers for TestNetwork {
 
 	fn add_peers_to_reserved_set(
 		&self,
-		_protocol: Cow<'static, str>,
+		_protocol: ProtocolName,
 		_peers: HashSet<Multiaddr>,
 	) -> Result<(), String> {
 		unimplemented!();
 	}
 
-	fn remove_peers_from_reserved_set(&self, _protocol: Cow<'static, str>, _peers: Vec<PeerId>) {}
+	fn remove_peers_from_reserved_set(&self, _protocol: ProtocolName, _peers: Vec<PeerId>) {}
 
 	fn add_to_peers_set(
 		&self,
-		_protocol: Cow<'static, str>,
+		_protocol: ProtocolName,
 		_peers: HashSet<Multiaddr>,
 	) -> Result<(), String> {
 		unimplemented!();
 	}
 
-	fn remove_from_peers_set(&self, _protocol: Cow<'static, str>, _peers: Vec<PeerId>) {
+	fn remove_from_peers_set(&self, _protocol: ProtocolName, _peers: Vec<PeerId>) {
 		unimplemented!();
 	}
 
@@ -143,14 +145,14 @@ impl NetworkEventStream for TestNetwork {
 }
 
 impl NetworkNotification for TestNetwork {
-	fn write_notification(&self, target: PeerId, _protocol: Cow<'static, str>, message: Vec<u8>) {
+	fn write_notification(&self, target: PeerId, _protocol: ProtocolName, message: Vec<u8>) {
 		let _ = self.sender.unbounded_send(Event::WriteNotification(target, message));
 	}
 
 	fn notification_sender(
 		&self,
 		_target: PeerId,
-		_protocol: Cow<'static, str>,
+		_protocol: ProtocolName,
 	) -> Result<Box<dyn NotificationSender>, NotificationSenderError> {
 		unimplemented!();
 	}

substrate/client/finality-grandpa/src/lib.rs

@@ -68,6 +68,7 @@ use sc_client_api::{
 	StorageProvider, TransactionFor,
 };
 use sc_consensus::BlockImport;
+use sc_network_common::protocol::ProtocolName;
 use sc_telemetry::{telemetry, TelemetryHandle, CONSENSUS_DEBUG, CONSENSUS_INFO};
 use sc_utils::mpsc::{tracing_unbounded, TracingUnboundedReceiver};
 use sp_api::ProvideRuntimeApi;
@@ -266,7 +267,7 @@ pub struct Config {
 	/// TelemetryHandle instance.
 	pub telemetry: Option<TelemetryHandle>,
 	/// Chain specific GRANDPA protocol name. See [`crate::protocol_standard_name`].
-	pub protocol_name: std::borrow::Cow<'static, str>,
+	pub protocol_name: ProtocolName,
 }
 
 impl Config {
@@ -723,7 +724,7 @@ pub struct GrandpaParams<Block: BlockT, C, N, SC, VR> {
 /// [`sc_network::config::NetworkConfiguration::extra_sets`].
 /// For standard protocol name see [`crate::protocol_standard_name`].
 pub fn grandpa_peers_set_config(
-	protocol_name: std::borrow::Cow<'static, str>,
+	protocol_name: ProtocolName,
 ) -> sc_network::config::NonDefaultSetConfig {
 	use communication::grandpa_protocol_name;
 	sc_network::config::NonDefaultSetConfig {

substrate/client/network-gossip/src/bridge.rs

@@ -21,7 +21,7 @@ use crate::{
 	Network, Validator,
 };
 
-use sc_network_common::protocol::event::Event;
+use sc_network_common::protocol::{event::Event, ProtocolName};
 use sc_peerset::ReputationChange;
 
 use futures::{
@@ -33,7 +33,6 @@ use log::trace;
 use prometheus_endpoint::Registry;
 use sp_runtime::traits::Block as BlockT;
 use std::{
-	borrow::Cow,
 	collections::{HashMap, VecDeque},
 	pin::Pin,
 	sync::Arc,
@@ -46,7 +45,7 @@ pub struct GossipEngine<B: BlockT> {
 	state_machine: ConsensusGossip<B>,
 	network: Box<dyn Network<B> + Send>,
 	periodic_maintenance_interval: futures_timer::Delay,
-	protocol: Cow<'static, str>,
+	protocol: ProtocolName,
 
 	/// Incoming events from the network.
 	network_event_stream: Pin<Box<dyn Stream<Item = Event> + Send>>,
@@ -78,7 +77,7 @@ impl<B: BlockT> GossipEngine<B> {
 	/// Create a new instance.
 	pub fn new<N: Network<B> + Send + Clone + 'static>(
 		network: N,
-		protocol: impl Into<Cow<'static, str>>,
+		protocol: impl Into<ProtocolName>,
 		validator: Arc<dyn Validator<B>>,
 		metrics_registry: Option<&Registry>,
 	) -> Self
@@ -329,7 +328,6 @@ mod tests {
 		traits::{Block as BlockT, NumberFor},
 	};
 	use std::{
-		borrow::Cow,
 		collections::HashSet,
 		sync::{Arc, Mutex},
 	};
@@ -360,7 +358,7 @@ mod tests {
 
 		fn report_peer(&self, _who: PeerId, _cost_benefit: ReputationChange) {}
 
-		fn disconnect_peer(&self, _who: PeerId, _protocol: Cow<'static, str>) {
+		fn disconnect_peer(&self, _who: PeerId, _protocol: ProtocolName) {
 			unimplemented!();
 		}
 
@@ -382,7 +380,7 @@ mod tests {
 
 		fn set_reserved_peers(
 			&self,
-			_protocol: Cow<'static, str>,
+			_protocol: ProtocolName,
 			_peers: HashSet<Multiaddr>,
 		) -> Result<(), String> {
 			unimplemented!();
@@ -390,28 +388,23 @@ mod tests {
 
 		fn add_peers_to_reserved_set(
 			&self,
-			_protocol: Cow<'static, str>,
+			_protocol: ProtocolName,
 			_peers: HashSet<Multiaddr>,
 		) -> Result<(), String> {
 			unimplemented!();
 		}
 
-		fn remove_peers_from_reserved_set(
-			&self,
-			_protocol: Cow<'static, str>,
-			_peers: Vec<PeerId>,
-		) {
-		}
+		fn remove_peers_from_reserved_set(&self, _protocol: ProtocolName, _peers: Vec<PeerId>) {}
 
 		fn add_to_peers_set(
 			&self,
-			_protocol: Cow<'static, str>,
+			_protocol: ProtocolName,
 			_peers: HashSet<Multiaddr>,
 		) -> Result<(), String> {
 			unimplemented!();
 		}
 
-		fn remove_from_peers_set(&self, _protocol: Cow<'static, str>, _peers: Vec<PeerId>) {
+		fn remove_from_peers_set(&self, _protocol: ProtocolName, _peers: Vec<PeerId>) {
 			unimplemented!();
 		}
 
@@ -430,19 +423,14 @@ mod tests {
 	}
 
 	impl NetworkNotification for TestNetwork {
-		fn write_notification(
-			&self,
-			_target: PeerId,
-			_protocol: Cow<'static, str>,
-			_message: Vec<u8>,
-		) {
+		fn write_notification(&self, _target: PeerId, _protocol: ProtocolName, _message: Vec<u8>) {
 			unimplemented!();
 		}
 
 		fn notification_sender(
 			&self,
 			_target: PeerId,
-			_protocol: Cow<'static, str>,
+			_protocol: ProtocolName,
 		) -> Result<Box<dyn NotificationSender>, NotificationSenderError> {
 			unimplemented!();
 		}
@@ -505,7 +493,7 @@ mod tests {
 	#[test]
 	fn keeps_multiple_subscribers_per_topic_updated_with_both_old_and_new_messages() {
 		let topic = H256::default();
-		let protocol = Cow::Borrowed("/my_protocol");
+		let protocol = ProtocolName::from("/my_protocol");
 		let remote_peer = PeerId::random();
 		let network = TestNetwork::default();
 
@@ -622,7 +610,7 @@ mod tests {
 		}
 
 		fn prop(channels: Vec<ChannelLengthAndTopic>, notifications: Vec<Vec<Message>>) {
-			let protocol = Cow::Borrowed("/my_protocol");
+			let protocol = ProtocolName::from("/my_protocol");
 			let remote_peer = PeerId::random();
 			let network = TestNetwork::default();
 

substrate/client/network-gossip/src/lib.rs

@@ -68,11 +68,12 @@ pub use self::{
 };
 
 use libp2p::{multiaddr, PeerId};
-use sc_network_common::service::{
-	NetworkBlock, NetworkEventStream, NetworkNotification, NetworkPeers,
+use sc_network_common::{
+	protocol::ProtocolName,
+	service::{NetworkBlock, NetworkEventStream, NetworkNotification, NetworkPeers},
 };
 use sp_runtime::traits::{Block as BlockT, NumberFor};
-use std::{borrow::Cow, iter};
+use std::iter;
 
 mod bridge;
 mod state_machine;
@@ -82,7 +83,7 @@ mod validator;
 pub trait Network<B: BlockT>:
 	NetworkPeers + NetworkEventStream + NetworkNotification + NetworkBlock<B::Hash, NumberFor<B>>
 {
-	fn add_set_reserved(&self, who: PeerId, protocol: Cow<'static, str>) {
+	fn add_set_reserved(&self, who: PeerId, protocol: ProtocolName) {
 		let addr =
 			iter::once(multiaddr::Protocol::P2p(who.into())).collect::<multiaddr::Multiaddr>();
 		let result = self.add_peers_to_reserved_set(protocol, iter::once(addr).collect());

substrate/client/network-gossip/src/state_machine.rs

@@ -22,9 +22,9 @@ use ahash::AHashSet;
 use libp2p::PeerId;
 use lru::LruCache;
 use prometheus_endpoint::{register, Counter, PrometheusError, Registry, U64};
-use sc_network_common::protocol::event::ObservedRole;
+use sc_network_common::protocol::{event::ObservedRole, ProtocolName};
 use sp_runtime::traits::{Block as BlockT, Hash, HashFor};
-use std::{borrow::Cow, collections::HashMap, iter, sync::Arc, time, time::Instant};
+use std::{collections::HashMap, iter, sync::Arc, time, time::Instant};
 
 // FIXME: Add additional spam/DoS attack protection: https://github.com/paritytech/substrate/issues/1115
 // NOTE: The current value is adjusted based on largest production network deployment (Kusama) and
@@ -99,7 +99,7 @@ impl<'g, 'p, B: BlockT> ValidatorContext<B> for NetworkContext<'g, 'p, B> {
 
 fn propagate<'a, B: BlockT, I>(
 	network: &mut dyn Network<B>,
-	protocol: Cow<'static, str>,
+	protocol: ProtocolName,
 	messages: I,
 	intent: MessageIntent,
 	peers: &mut HashMap<PeerId, PeerConsensus<B::Hash>>,
@@ -155,7 +155,7 @@ pub struct ConsensusGossip<B: BlockT> {
 	peers: HashMap<PeerId, PeerConsensus<B::Hash>>,
 	messages: Vec<MessageEntry<B>>,
 	known_messages: LruCache<B::Hash, ()>,
-	protocol: Cow<'static, str>,
+	protocol: ProtocolName,
 	validator: Arc<dyn Validator<B>>,
 	next_broadcast: Instant,
 	metrics: Option<Metrics>,
@@ -165,7 +165,7 @@ impl<B: BlockT> ConsensusGossip<B> {
 	/// Create a new instance using the given validator.
 	pub fn new(
 		validator: Arc<dyn Validator<B>>,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		metrics_registry: Option<&Registry>,
 	) -> Self {
 		let metrics = match metrics_registry.map(Metrics::register) {
@@ -527,7 +527,6 @@ mod tests {
 		traits::NumberFor,
 	};
 	use std::{
-		borrow::Cow,
 		collections::HashSet,
 		pin::Pin,
 		sync::{Arc, Mutex},
@@ -599,7 +598,7 @@ mod tests {
 			self.inner.lock().unwrap().peer_reports.push((who, cost_benefit));
 		}
 
-		fn disconnect_peer(&self, _who: PeerId, _protocol: Cow<'static, str>) {
+		fn disconnect_peer(&self, _who: PeerId, _protocol: ProtocolName) {
 			unimplemented!();
 		}
 
@@ -621,7 +620,7 @@ mod tests {
 
 		fn set_reserved_peers(
 			&self,
-			_protocol: Cow<'static, str>,
+			_protocol: ProtocolName,
 			_peers: HashSet<Multiaddr>,
 		) -> Result<(), String> {
 			unimplemented!();
@@ -629,28 +628,23 @@ mod tests {
 
 		fn add_peers_to_reserved_set(
 			&self,
-			_protocol: Cow<'static, str>,
+			_protocol: ProtocolName,
 			_peers: HashSet<Multiaddr>,
 		) -> Result<(), String> {
 			unimplemented!();
 		}
 
-		fn remove_peers_from_reserved_set(
-			&self,
-			_protocol: Cow<'static, str>,
-			_peers: Vec<PeerId>,
-		) {
-		}
+		fn remove_peers_from_reserved_set(&self, _protocol: ProtocolName, _peers: Vec<PeerId>) {}
 
 		fn add_to_peers_set(
 			&self,
-			_protocol: Cow<'static, str>,
+			_protocol: ProtocolName,
 			_peers: HashSet<Multiaddr>,
 		) -> Result<(), String> {
 			unimplemented!();
 		}
 
-		fn remove_from_peers_set(&self, _protocol: Cow<'static, str>, _peers: Vec<PeerId>) {
+		fn remove_from_peers_set(&self, _protocol: ProtocolName, _peers: Vec<PeerId>) {
 			unimplemented!();
 		}
 
@@ -666,19 +660,14 @@ mod tests {
 	}
 
 	impl NetworkNotification for NoOpNetwork {
-		fn write_notification(
-			&self,
-			_target: PeerId,
-			_protocol: Cow<'static, str>,
-			_message: Vec<u8>,
-		) {
+		fn write_notification(&self, _target: PeerId, _protocol: ProtocolName, _message: Vec<u8>) {
 			unimplemented!();
 		}
 
 		fn notification_sender(
 			&self,
 			_target: PeerId,
-			_protocol: Cow<'static, str>,
+			_protocol: ProtocolName,
 		) -> Result<Box<dyn NotificationSender>, NotificationSenderError> {
 			unimplemented!();
 		}

substrate/client/network/common/src/config.rs

@@ -21,7 +21,9 @@
 use libp2p::{multiaddr, Multiaddr, PeerId};
 use std::{fmt, str, str::FromStr};
 
-/// Name of a protocol, transmitted on the wire. Should be unique for each chain. Always UTF-8.
+/// Protocol name prefix, transmitted on the wire for legacy protocol names.
+/// I.e., `dot` in `/dot/sync/2`. Should be unique for each chain. Always UTF-8.
+/// Deprecated in favour of genesis hash & fork ID based protocol names.
 #[derive(Clone, PartialEq, Eq, Hash)]
 pub struct ProtocolId(smallvec::SmallVec<[u8; 6]>);
 

substrate/client/network/common/src/protocol.rs

@@ -16,4 +16,131 @@
 // You should have received a copy of the GNU General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
+use std::{
+	borrow::Borrow,
+	fmt,
+	hash::{Hash, Hasher},
+	ops::Deref,
+	sync::Arc,
+};
+
+use libp2p::core::upgrade;
+
 pub mod event;
+
+/// The protocol name transmitted on the wire.
+#[derive(Debug, Clone)]
+pub enum ProtocolName {
+	/// The protocol name as a static string.
+	Static(&'static str),
+	/// The protocol name as a dynamically allocated string.
+	OnHeap(Arc<str>),
+}
+
+impl From<&'static str> for ProtocolName {
+	fn from(name: &'static str) -> Self {
+		Self::Static(name)
+	}
+}
+
+impl From<Arc<str>> for ProtocolName {
+	fn from(name: Arc<str>) -> Self {
+		Self::OnHeap(name)
+	}
+}
+
+impl From<String> for ProtocolName {
+	fn from(name: String) -> Self {
+		Self::OnHeap(Arc::from(name))
+	}
+}
+
+impl Deref for ProtocolName {
+	type Target = str;
+
+	fn deref(&self) -> &str {
+		match self {
+			Self::Static(name) => name,
+			Self::OnHeap(name) => &name,
+		}
+	}
+}
+
+impl Borrow<str> for ProtocolName {
+	fn borrow(&self) -> &str {
+		self
+	}
+}
+
+impl PartialEq for ProtocolName {
+	fn eq(&self, other: &Self) -> bool {
+		(self as &str) == (other as &str)
+	}
+}
+
+impl Eq for ProtocolName {}
+
+impl Hash for ProtocolName {
+	fn hash<H: Hasher>(&self, state: &mut H) {
+		(self as &str).hash(state)
+	}
+}
+
+impl fmt::Display for ProtocolName {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		f.write_str(self)
+	}
+}
+
+impl upgrade::ProtocolName for ProtocolName {
+	fn protocol_name(&self) -> &[u8] {
+		(self as &str).as_bytes()
+	}
+}
+
+#[cfg(test)]
+mod tests {
+	use super::ProtocolName;
+	use std::{
+		borrow::Borrow,
+		collections::hash_map::DefaultHasher,
+		hash::{Hash, Hasher},
+	};
+
+	#[test]
+	fn protocol_name_keys_are_equivalent_to_str_keys() {
+		const PROTOCOL: &'static str = "/some/protocol/1";
+		let static_protocol_name = ProtocolName::from(PROTOCOL);
+		let on_heap_protocol_name = ProtocolName::from(String::from(PROTOCOL));
+
+		assert_eq!(<ProtocolName as Borrow<str>>::borrow(&static_protocol_name), PROTOCOL);
+		assert_eq!(<ProtocolName as Borrow<str>>::borrow(&on_heap_protocol_name), PROTOCOL);
+		assert_eq!(static_protocol_name, on_heap_protocol_name);
+
+		assert_eq!(hash(static_protocol_name), hash(PROTOCOL));
+		assert_eq!(hash(on_heap_protocol_name), hash(PROTOCOL));
+	}
+
+	#[test]
+	fn different_protocol_names_do_not_compare_equal() {
+		const PROTOCOL1: &'static str = "/some/protocol/1";
+		let static_protocol_name1 = ProtocolName::from(PROTOCOL1);
+		let on_heap_protocol_name1 = ProtocolName::from(String::from(PROTOCOL1));
+
+		const PROTOCOL2: &'static str = "/some/protocol/2";
+		let static_protocol_name2 = ProtocolName::from(PROTOCOL2);
+		let on_heap_protocol_name2 = ProtocolName::from(String::from(PROTOCOL2));
+
+		assert_ne!(<ProtocolName as Borrow<str>>::borrow(&static_protocol_name1), PROTOCOL2);
+		assert_ne!(<ProtocolName as Borrow<str>>::borrow(&on_heap_protocol_name1), PROTOCOL2);
+		assert_ne!(static_protocol_name1, static_protocol_name2);
+		assert_ne!(static_protocol_name1, on_heap_protocol_name2);
+		assert_ne!(on_heap_protocol_name1, on_heap_protocol_name2);
+	}
+
+	fn hash<T: Hash>(x: T) -> u64 {
+		let mut hasher = DefaultHasher::new();
+		x.hash(&mut hasher);
+		hasher.finish()
+	}
+}

substrate/client/network/common/src/protocol/event.rs

@@ -19,9 +19,9 @@
 //! Network event types. These are are not the part of the protocol, but rather
 //! events that happen on the network like DHT get/put results received.
 
+use super::ProtocolName;
 use bytes::Bytes;
 use libp2p::{core::PeerId, kad::record::Key};
-use std::borrow::Cow;
 
 /// Events generated by DHT as a response to get_value and put_value requests.
 #[derive(Debug, Clone)]
@@ -69,13 +69,13 @@ pub enum Event {
 		/// This is always equal to the value of
 		/// `sc_network::config::NonDefaultSetConfig::notifications_protocol` of one of the
 		/// configured sets.
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		/// If the negotiation didn't use the main name of the protocol (the one in
 		/// `notifications_protocol`), then this field contains which name has actually been
 		/// used.
 		/// Always contains a value equal to the value in
 		/// `sc_network::config::NonDefaultSetConfig::fallback_names`.
-		negotiated_fallback: Option<Cow<'static, str>>,
+		negotiated_fallback: Option<ProtocolName>,
 		/// Role of the remote.
 		role: ObservedRole,
 	},
@@ -86,7 +86,7 @@ pub enum Event {
 		/// Node we closed the substream with.
 		remote: PeerId,
 		/// The concerned protocol. Each protocol uses a different substream.
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 	},
 
 	/// Received one or more messages from the given node using the given protocol.
@@ -94,7 +94,7 @@ pub enum Event {
 		/// Node we received the message from.
 		remote: PeerId,
 		/// Concerned protocol and associated message.
-		messages: Vec<(Cow<'static, str>, Bytes)>,
+		messages: Vec<(ProtocolName, Bytes)>,
 	},
 }
 

substrate/client/network/common/src/request_responses.rs

@@ -18,19 +18,20 @@
 
 //! Collection of generic data structures for request-response protocols.
 
+use crate::protocol::ProtocolName;
 use futures::channel::{mpsc, oneshot};
 use libp2p::{request_response::OutboundFailure, PeerId};
 use sc_peerset::ReputationChange;
-use std::{borrow::Cow, time::Duration};
+use std::time::Duration;
 
 /// Configuration for a single request-response protocol.
 #[derive(Debug, Clone)]
 pub struct ProtocolConfig {
 	/// Name of the protocol on the wire. Should be something like `/foo/bar`.
-	pub name: Cow<'static, str>,
+	pub name: ProtocolName,
 
 	/// Fallback on the wire protocol names to support.
-	pub fallback_names: Vec<Cow<'static, str>>,
+	pub fallback_names: Vec<ProtocolName>,
 
 	/// Maximum allowed size, in bytes, of a request.
 	///

substrate/client/network/common/src/service.rs

@@ -20,7 +20,7 @@
 
 use crate::{
 	config::MultiaddrWithPeerId,
-	protocol::event::Event,
+	protocol::{event::Event, ProtocolName},
 	request_responses::{IfDisconnected, RequestFailure},
 	sync::{warp::WarpSyncProgress, StateDownloadProgress, SyncState},
 };
@@ -30,7 +30,7 @@ use libp2p::{Multiaddr, PeerId};
 use sc_peerset::ReputationChange;
 pub use signature::Signature;
 use sp_runtime::traits::{Block as BlockT, NumberFor};
-use std::{borrow::Cow, collections::HashSet, future::Future, pin::Pin, sync::Arc};
+use std::{collections::HashSet, future::Future, pin::Pin, sync::Arc};
 
 mod signature;
 
@@ -171,7 +171,7 @@ pub trait NetworkPeers {
 	/// See also [`NetworkPeers::remove_from_peers_set`], which has the same effect but also
 	/// prevents the local node from re-establishing an outgoing substream to this peer until it
 	/// is added again.
-	fn disconnect_peer(&self, who: PeerId, protocol: Cow<'static, str>);
+	fn disconnect_peer(&self, who: PeerId, protocol: ProtocolName);
 
 	/// Connect to unreserved peers and allow unreserved peers to connect for syncing purposes.
 	fn accept_unreserved_peers(&self);
@@ -207,7 +207,7 @@ pub trait NetworkPeers {
 	/// invalid peer ID (which includes the local peer ID).
 	fn set_reserved_peers(
 		&self,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		peers: HashSet<Multiaddr>,
 	) -> Result<(), String>;
 
@@ -220,12 +220,12 @@ pub trait NetworkPeers {
 	/// invalid peer ID (which includes the local peer ID).
 	fn add_peers_to_reserved_set(
 		&self,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		peers: HashSet<Multiaddr>,
 	) -> Result<(), String>;
 
 	/// Remove peers from a peer set.
-	fn remove_peers_from_reserved_set(&self, protocol: Cow<'static, str>, peers: Vec<PeerId>);
+	fn remove_peers_from_reserved_set(&self, protocol: ProtocolName, peers: Vec<PeerId>);
 
 	/// Add a peer to a set of peers.
 	///
@@ -238,14 +238,14 @@ pub trait NetworkPeers {
 	/// invalid peer ID (which includes the local peer ID).
 	fn add_to_peers_set(
 		&self,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		peers: HashSet<Multiaddr>,
 	) -> Result<(), String>;
 
 	/// Remove peers from a peer set.
 	///
 	/// If we currently have an open substream with this peer, it will soon be closed.
-	fn remove_from_peers_set(&self, protocol: Cow<'static, str>, peers: Vec<PeerId>);
+	fn remove_from_peers_set(&self, protocol: ProtocolName, peers: Vec<PeerId>);
 
 	/// Returns the number of peers in the sync peer set we're connected to.
 	fn sync_num_connected(&self) -> usize;
@@ -273,7 +273,7 @@ where
 		T::report_peer(self, who, cost_benefit)
 	}
 
-	fn disconnect_peer(&self, who: PeerId, protocol: Cow<'static, str>) {
+	fn disconnect_peer(&self, who: PeerId, protocol: ProtocolName) {
 		T::disconnect_peer(self, who, protocol)
 	}
 
@@ -295,7 +295,7 @@ where
 
 	fn set_reserved_peers(
 		&self,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		peers: HashSet<Multiaddr>,
 	) -> Result<(), String> {
 		T::set_reserved_peers(self, protocol, peers)
@@ -303,25 +303,25 @@ where
 
 	fn add_peers_to_reserved_set(
 		&self,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		peers: HashSet<Multiaddr>,
 	) -> Result<(), String> {
 		T::add_peers_to_reserved_set(self, protocol, peers)
 	}
 
-	fn remove_peers_from_reserved_set(&self, protocol: Cow<'static, str>, peers: Vec<PeerId>) {
+	fn remove_peers_from_reserved_set(&self, protocol: ProtocolName, peers: Vec<PeerId>) {
 		T::remove_peers_from_reserved_set(self, protocol, peers)
 	}
 
 	fn add_to_peers_set(
 		&self,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		peers: HashSet<Multiaddr>,
 	) -> Result<(), String> {
 		T::add_to_peers_set(self, protocol, peers)
 	}
 
-	fn remove_from_peers_set(&self, protocol: Cow<'static, str>, peers: Vec<PeerId>) {
+	fn remove_from_peers_set(&self, protocol: ProtocolName, peers: Vec<PeerId>) {
 		T::remove_from_peers_set(self, protocol, peers)
 	}
 
@@ -431,7 +431,7 @@ pub trait NetworkNotification {
 	///
 	/// The protocol must have been registered with
 	/// `crate::config::NetworkConfiguration::notifications_protocols`.
-	fn write_notification(&self, target: PeerId, protocol: Cow<'static, str>, message: Vec<u8>);
+	fn write_notification(&self, target: PeerId, protocol: ProtocolName, message: Vec<u8>);
 
 	/// Obtains a [`NotificationSender`] for a connected peer, if it exists.
 	///
@@ -502,7 +502,7 @@ pub trait NetworkNotification {
 	fn notification_sender(
 		&self,
 		target: PeerId,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 	) -> Result<Box<dyn NotificationSender>, NotificationSenderError>;
 }
 
@@ -511,14 +511,14 @@ where
 	T: ?Sized,
 	T: NetworkNotification,
 {
-	fn write_notification(&self, target: PeerId, protocol: Cow<'static, str>, message: Vec<u8>) {
+	fn write_notification(&self, target: PeerId, protocol: ProtocolName, message: Vec<u8>) {
 		T::write_notification(self, target, protocol, message)
 	}
 
 	fn notification_sender(
 		&self,
 		target: PeerId,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 	) -> Result<Box<dyn NotificationSender>, NotificationSenderError> {
 		T::notification_sender(self, target, protocol)
 	}
@@ -547,7 +547,7 @@ pub trait NetworkRequest {
 	async fn request(
 		&self,
 		target: PeerId,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		request: Vec<u8>,
 		connect: IfDisconnected,
 	) -> Result<Vec<u8>, RequestFailure>;
@@ -565,7 +565,7 @@ pub trait NetworkRequest {
 	fn start_request(
 		&self,
 		target: PeerId,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		request: Vec<u8>,
 		tx: oneshot::Sender<Result<Vec<u8>, RequestFailure>>,
 		connect: IfDisconnected,
@@ -581,7 +581,7 @@ where
 	fn request<'life0, 'async_trait>(
 		&'life0 self,
 		target: PeerId,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		request: Vec<u8>,
 		connect: IfDisconnected,
 	) -> Pin<Box<dyn Future<Output = Result<Vec<u8>, RequestFailure>> + Send + 'async_trait>>
@@ -595,7 +595,7 @@ where
 	fn start_request(
 		&self,
 		target: PeerId,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		request: Vec<u8>,
 		tx: oneshot::Sender<Result<Vec<u8>, RequestFailure>>,
 		connect: IfDisconnected,

substrate/client/network/src/behaviour.rs

@@ -42,7 +42,10 @@ use log::debug;
 use sc_consensus::import_queue::{IncomingBlock, Origin};
 use sc_network_common::{
 	config::ProtocolId,
-	protocol::event::{DhtEvent, ObservedRole},
+	protocol::{
+		event::{DhtEvent, ObservedRole},
+		ProtocolName,
+	},
 	request_responses::{IfDisconnected, ProtocolConfig, RequestFailure},
 };
 use sc_peerset::PeersetHandle;
@@ -53,7 +56,6 @@ use sp_runtime::{
 	Justifications,
 };
 use std::{
-	borrow::Cow,
 	collections::{HashSet, VecDeque},
 	iter,
 	task::{Context, Poll},
@@ -117,7 +119,7 @@ pub enum BehaviourOut<B: BlockT> {
 		/// Peer which sent us a request.
 		peer: PeerId,
 		/// Protocol name of the request.
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		/// If `Ok`, contains the time elapsed between when we received the request and when we
 		/// sent back the response. If `Err`, the error that happened.
 		result: Result<Duration, ResponseFailure>,
@@ -130,7 +132,7 @@ pub enum BehaviourOut<B: BlockT> {
 		/// Peer that we send a request to.
 		peer: PeerId,
 		/// Name of the protocol in question.
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		/// Duration the request took.
 		duration: Duration,
 		/// Result of the request.
@@ -144,12 +146,12 @@ pub enum BehaviourOut<B: BlockT> {
 		/// Node we opened the substream with.
 		remote: PeerId,
 		/// The concerned protocol. Each protocol uses a different substream.
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		/// If the negotiation didn't use the main name of the protocol (the one in
 		/// `notifications_protocol`), then this field contains which name has actually been
 		/// used.
 		/// See also [`crate::Event::NotificationStreamOpened`].
-		negotiated_fallback: Option<Cow<'static, str>>,
+		negotiated_fallback: Option<ProtocolName>,
 		/// Object that permits sending notifications to the peer.
 		notifications_sink: NotificationsSink,
 		/// Role of the remote.
@@ -165,7 +167,7 @@ pub enum BehaviourOut<B: BlockT> {
 		/// Id of the peer we are connected to.
 		remote: PeerId,
 		/// The concerned protocol. Each protocol uses a different substream.
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		/// Replacement for the previous [`NotificationsSink`].
 		notifications_sink: NotificationsSink,
 	},
@@ -176,7 +178,7 @@ pub enum BehaviourOut<B: BlockT> {
 		/// Node we closed the substream with.
 		remote: PeerId,
 		/// The concerned protocol. Each protocol uses a different substream.
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 	},
 
 	/// Received one or more messages from the given node using the given protocol.
@@ -184,7 +186,7 @@ pub enum BehaviourOut<B: BlockT> {
 		/// Node we received the message from.
 		remote: PeerId,
 		/// Concerned protocol and associated message.
-		messages: Vec<(Cow<'static, str>, Bytes)>,
+		messages: Vec<(ProtocolName, Bytes)>,
 	},
 
 	/// Now connected to a new peer for syncing purposes.

substrate/client/network/src/config.rs

@@ -41,10 +41,9 @@ use libp2p::{
 };
 use prometheus_endpoint::Registry;
 use sc_consensus::ImportQueue;
-use sc_network_common::{config::MultiaddrWithPeerId, sync::ChainSync};
+use sc_network_common::{config::MultiaddrWithPeerId, protocol::ProtocolName, sync::ChainSync};
 use sp_runtime::traits::Block as BlockT;
 use std::{
-	borrow::Cow,
 	collections::HashMap,
 	error::Error,
 	fs,
@@ -431,14 +430,14 @@ pub struct NonDefaultSetConfig {
 	///
 	/// > **Note**: This field isn't present for the default set, as this is handled internally
 	/// > by the networking code.
-	pub notifications_protocol: Cow<'static, str>,
+	pub notifications_protocol: ProtocolName,
 	/// If the remote reports that it doesn't support the protocol indicated in the
 	/// `notifications_protocol` field, then each of these fallback names will be tried one by
 	/// one.
 	///
 	/// If a fallback is used, it will be reported in
 	/// [`crate::Event::NotificationStreamOpened::negotiated_fallback`].
-	pub fallback_names: Vec<Cow<'static, str>>,
+	pub fallback_names: Vec<ProtocolName>,
 	/// Maximum allowed size of single notifications.
 	pub max_notification_size: u64,
 	/// Base configuration.
@@ -447,7 +446,7 @@ pub struct NonDefaultSetConfig {
 
 impl NonDefaultSetConfig {
 	/// Creates a new [`NonDefaultSetConfig`]. Zero slots and accepts only reserved nodes.
-	pub fn new(notifications_protocol: Cow<'static, str>, max_notification_size: u64) -> Self {
+	pub fn new(notifications_protocol: ProtocolName, max_notification_size: u64) -> Self {
 		Self {
 			notifications_protocol,
 			max_notification_size,
@@ -476,7 +475,7 @@ impl NonDefaultSetConfig {
 	/// Add a list of protocol names used for backward compatibility.
 	///
 	/// See the explanations in [`NonDefaultSetConfig::fallback_names`].
-	pub fn add_fallback_names(&mut self, fallback_names: Vec<Cow<'static, str>>) {
+	pub fn add_fallback_names(&mut self, fallback_names: Vec<ProtocolName>) {
 		self.fallback_names.extend(fallback_names);
 	}
 }

substrate/client/network/src/error.rs

@@ -20,8 +20,9 @@
 
 use crate::config::TransportConfig;
 use libp2p::{Multiaddr, PeerId};
+use sc_network_common::protocol::ProtocolName;
 
-use std::{borrow::Cow, fmt};
+use std::fmt;
 
 /// Result type alias for the network.
 pub type Result<T> = std::result::Result<T, Error>;
@@ -65,7 +66,7 @@ pub enum Error {
 	#[error("Request-response protocol registered multiple times: {protocol}")]
 	DuplicateRequestResponseProtocol {
 		/// Name of the protocol registered multiple times.
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 	},
 }
 

substrate/client/network/src/lib.rs

@@ -264,7 +264,10 @@ pub mod transactions;
 pub use libp2p::{multiaddr, Multiaddr, PeerId};
 pub use protocol::PeerInfo;
 pub use sc_network_common::{
-	protocol::event::{DhtEvent, Event, ObservedRole},
+	protocol::{
+		event::{DhtEvent, Event, ObservedRole},
+		ProtocolName,
+	},
 	request_responses::{IfDisconnected, RequestFailure},
 	service::{
 		KademliaKey, NetworkBlock, NetworkDHTProvider, NetworkRequest, NetworkSigner,

substrate/client/network/src/protocol.rs

@@ -44,6 +44,7 @@ use sc_client_api::HeaderBackend;
 use sc_consensus::import_queue::{BlockImportError, BlockImportStatus, IncomingBlock, Origin};
 use sc_network_common::{
 	config::ProtocolId,
+	protocol::ProtocolName,
 	request_responses::RequestFailure,
 	sync::{
 		message::{
@@ -63,7 +64,6 @@ use sp_runtime::{
 	Justifications,
 };
 use std::{
-	borrow::Cow,
 	collections::{HashMap, HashSet, VecDeque},
 	io, iter,
 	num::NonZeroUsize,
@@ -190,7 +190,7 @@ pub struct Protocol<B: BlockT, Client> {
 	/// Handles opening the unique substream and sending and receiving raw messages.
 	behaviour: Notifications,
 	/// List of notifications protocols that have been registered.
-	notification_protocols: Vec<Cow<'static, str>>,
+	notification_protocols: Vec<ProtocolName>,
 	/// If we receive a new "substream open" event that contains an invalid handshake, we ask the
 	/// inner layer to force-close the substream. Force-closing the substream will generate a
 	/// "substream closed" event. This is a problem: since we can't propagate the "substream open"
@@ -460,7 +460,7 @@ where
 	}
 
 	/// Disconnects the given peer if we are connected to it.
-	pub fn disconnect_peer(&mut self, peer_id: &PeerId, protocol_name: &str) {
+	pub fn disconnect_peer(&mut self, peer_id: &PeerId, protocol_name: ProtocolName) {
 		if let Some(position) = self.notification_protocols.iter().position(|p| *p == protocol_name)
 		{
 			self.behaviour.disconnect_peer(
@@ -1085,7 +1085,7 @@ where
 	}
 
 	/// Sets the list of reserved peers for the given protocol/peerset.
-	pub fn set_reserved_peerset_peers(&self, protocol: Cow<'static, str>, peers: HashSet<PeerId>) {
+	pub fn set_reserved_peerset_peers(&self, protocol: ProtocolName, peers: HashSet<PeerId>) {
 		if let Some(index) = self.notification_protocols.iter().position(|p| *p == protocol) {
 			self.peerset_handle
 				.set_reserved_peers(sc_peerset::SetId::from(index + NUM_HARDCODED_PEERSETS), peers);
@@ -1099,7 +1099,7 @@ where
 	}
 
 	/// Removes a `PeerId` from the list of reserved peers.
-	pub fn remove_set_reserved_peer(&self, protocol: Cow<'static, str>, peer: PeerId) {
+	pub fn remove_set_reserved_peer(&self, protocol: ProtocolName, peer: PeerId) {
 		if let Some(index) = self.notification_protocols.iter().position(|p| *p == protocol) {
 			self.peerset_handle.remove_reserved_peer(
 				sc_peerset::SetId::from(index + NUM_HARDCODED_PEERSETS),
@@ -1115,7 +1115,7 @@ where
 	}
 
 	/// Adds a `PeerId` to the list of reserved peers.
-	pub fn add_set_reserved_peer(&self, protocol: Cow<'static, str>, peer: PeerId) {
+	pub fn add_set_reserved_peer(&self, protocol: ProtocolName, peer: PeerId) {
 		if let Some(index) = self.notification_protocols.iter().position(|p| *p == protocol) {
 			self.peerset_handle
 				.add_reserved_peer(sc_peerset::SetId::from(index + NUM_HARDCODED_PEERSETS), peer);
@@ -1138,7 +1138,7 @@ where
 	}
 
 	/// Add a peer to a peers set.
-	pub fn add_to_peers_set(&self, protocol: Cow<'static, str>, peer: PeerId) {
+	pub fn add_to_peers_set(&self, protocol: ProtocolName, peer: PeerId) {
 		if let Some(index) = self.notification_protocols.iter().position(|p| *p == protocol) {
 			self.peerset_handle
 				.add_to_peers_set(sc_peerset::SetId::from(index + NUM_HARDCODED_PEERSETS), peer);
@@ -1152,7 +1152,7 @@ where
 	}
 
 	/// Remove a peer from a peers set.
-	pub fn remove_from_peers_set(&self, protocol: Cow<'static, str>, peer: PeerId) {
+	pub fn remove_from_peers_set(&self, protocol: ProtocolName, peer: PeerId) {
 		if let Some(index) = self.notification_protocols.iter().position(|p| *p == protocol) {
 			self.peerset_handle.remove_from_peers_set(
 				sc_peerset::SetId::from(index + NUM_HARDCODED_PEERSETS),
@@ -1259,27 +1259,27 @@ pub enum CustomMessageOutcome<B: BlockT> {
 	/// Notification protocols have been opened with a remote.
 	NotificationStreamOpened {
 		remote: PeerId,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		/// See [`crate::Event::NotificationStreamOpened::negotiated_fallback`].
-		negotiated_fallback: Option<Cow<'static, str>>,
+		negotiated_fallback: Option<ProtocolName>,
 		roles: Roles,
 		notifications_sink: NotificationsSink,
 	},
 	/// The [`NotificationsSink`] of some notification protocols need an update.
 	NotificationStreamReplaced {
 		remote: PeerId,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		notifications_sink: NotificationsSink,
 	},
 	/// Notification protocols have been closed with a remote.
 	NotificationStreamClosed {
 		remote: PeerId,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 	},
 	/// Messages have been received on one or more notifications protocols.
 	NotificationsReceived {
 		remote: PeerId,
-		messages: Vec<(Cow<'static, str>, Bytes)>,
+		messages: Vec<(ProtocolName, Bytes)>,
 	},
 	/// A new block request must be emitted.
 	BlockRequest {

substrate/client/network/src/protocol/notifications/behaviour.rs

@@ -33,15 +33,14 @@ use libp2p::{
 use log::{error, trace, warn};
 use parking_lot::RwLock;
 use rand::distributions::{Distribution as _, Uniform};
+use sc_network_common::protocol::ProtocolName;
 use sc_peerset::DropReason;
 use smallvec::SmallVec;
 use std::{
-	borrow::Cow,
 	cmp,
 	collections::{hash_map::Entry, VecDeque},
 	mem,
 	pin::Pin,
-	str,
 	sync::Arc,
 	task::{Context, Poll},
 	time::{Duration, Instant},
@@ -140,9 +139,9 @@ pub struct Notifications {
 #[derive(Debug, Clone)]
 pub struct ProtocolConfig {
 	/// Name of the protocol.
-	pub name: Cow<'static, str>,
+	pub name: ProtocolName,
 	/// Names of the protocol to use if the main one isn't available.
-	pub fallback_names: Vec<Cow<'static, str>>,
+	pub fallback_names: Vec<ProtocolName>,
 	/// Handshake of the protocol.
 	pub handshake: Vec<u8>,
 	/// Maximum allowed size for a notification.
@@ -309,7 +308,7 @@ pub enum NotificationsOut {
 		set_id: sc_peerset::SetId,
 		/// If `Some`, a fallback protocol name has been used rather the main protocol name.
 		/// Always matches one of the fallback names passed at initialization.
-		negotiated_fallback: Option<Cow<'static, str>>,
+		negotiated_fallback: Option<ProtocolName>,
 		/// Handshake that was sent to us.
 		/// This is normally a "Status" message, but this is out of the concern of this code.
 		received_handshake: Vec<u8>,

substrate/client/network/src/protocol/notifications/handler.rs

@@ -80,12 +80,11 @@ use libp2p::{
 };
 use log::error;
 use parking_lot::{Mutex, RwLock};
+use sc_network_common::protocol::ProtocolName;
 use std::{
-	borrow::Cow,
 	collections::VecDeque,
 	mem,
 	pin::Pin,
-	str,
 	sync::Arc,
 	task::{Context, Poll},
 	time::{Duration, Instant},
@@ -146,9 +145,9 @@ pub struct NotifsHandler {
 #[derive(Debug, Clone)]
 pub struct ProtocolConfig {
 	/// Name of the protocol.
-	pub name: Cow<'static, str>,
+	pub name: ProtocolName,
 	/// Names of the protocol to use if the main one isn't available.
-	pub fallback_names: Vec<Cow<'static, str>>,
+	pub fallback_names: Vec<ProtocolName>,
 	/// Handshake of the protocol. The `RwLock` is locked every time a new substream is opened.
 	pub handshake: Arc<RwLock<Vec<u8>>>,
 	/// Maximum allowed size for a notification.
@@ -297,7 +296,7 @@ pub enum NotifsHandlerOut {
 		/// Index of the protocol in the list of protocols passed at initialization.
 		protocol_index: usize,
 		/// Name of the protocol that was actually negotiated, if the default one wasn't available.
-		negotiated_fallback: Option<Cow<'static, str>>,
+		negotiated_fallback: Option<ProtocolName>,
 		/// The endpoint of the connection that is open for custom protocols.
 		endpoint: ConnectedPoint,
 		/// Handshake that was sent to us.

substrate/client/network/src/protocol/notifications/upgrade/notifications.rs

@@ -39,8 +39,8 @@ use bytes::BytesMut;
 use futures::prelude::*;
 use libp2p::core::{upgrade, InboundUpgrade, OutboundUpgrade, UpgradeInfo};
 use log::{error, warn};
+use sc_network_common::protocol::ProtocolName;
 use std::{
-	borrow::Cow,
 	convert::Infallible,
 	io, mem,
 	pin::Pin,
@@ -58,7 +58,7 @@ const MAX_HANDSHAKE_SIZE: usize = 1024;
 pub struct NotificationsIn {
 	/// Protocol name to use when negotiating the substream.
 	/// The first one is the main name, while the other ones are fall backs.
-	protocol_names: Vec<Cow<'static, str>>,
+	protocol_names: Vec<ProtocolName>,
 	/// Maximum allowed size for a single notification.
 	max_notification_size: u64,
 }
@@ -69,7 +69,7 @@ pub struct NotificationsIn {
 pub struct NotificationsOut {
 	/// Protocol name to use when negotiating the substream.
 	/// The first one is the main name, while the other ones are fall backs.
-	protocol_names: Vec<Cow<'static, str>>,
+	protocol_names: Vec<ProtocolName>,
 	/// Message to send when we start the handshake.
 	initial_message: Vec<u8>,
 	/// Maximum allowed size for a single notification.
@@ -114,8 +114,8 @@ pub struct NotificationsOutSubstream<TSubstream> {
 impl NotificationsIn {
 	/// Builds a new potential upgrade.
 	pub fn new(
-		main_protocol_name: impl Into<Cow<'static, str>>,
-		fallback_names: Vec<Cow<'static, str>>,
+		main_protocol_name: impl Into<ProtocolName>,
+		fallback_names: Vec<ProtocolName>,
 		max_notification_size: u64,
 	) -> Self {
 		let mut protocol_names = fallback_names;
@@ -126,16 +126,11 @@ impl NotificationsIn {
 }
 
 impl UpgradeInfo for NotificationsIn {
-	type Info = StringProtocolName;
+	type Info = ProtocolName;
 	type InfoIter = vec::IntoIter<Self::Info>;
 
 	fn protocol_info(&self) -> Self::InfoIter {
-		self.protocol_names
-			.iter()
-			.cloned()
-			.map(StringProtocolName)
-			.collect::<Vec<_>>()
-			.into_iter()
+		self.protocol_names.clone().into_iter()
 	}
 }
 
@@ -172,10 +167,10 @@ where
 
 			Ok(NotificationsInOpen {
 				handshake,
-				negotiated_fallback: if negotiated_name.0 == self.protocol_names[0] {
+				negotiated_fallback: if negotiated_name == self.protocol_names[0] {
 					None
 				} else {
-					Some(negotiated_name.0)
+					Some(negotiated_name)
 				},
 				substream,
 			})
@@ -189,7 +184,7 @@ pub struct NotificationsInOpen<TSubstream> {
 	pub handshake: Vec<u8>,
 	/// If the negotiated name is not the "main" protocol name but a fallback, contains the
 	/// name of the negotiated fallback.
-	pub negotiated_fallback: Option<Cow<'static, str>>,
+	pub negotiated_fallback: Option<ProtocolName>,
 	/// Implementation of `Stream` that allows receives messages from the substream.
 	pub substream: NotificationsInSubstream<TSubstream>,
 }
@@ -334,8 +329,8 @@ where
 impl NotificationsOut {
 	/// Builds a new potential upgrade.
 	pub fn new(
-		main_protocol_name: impl Into<Cow<'static, str>>,
-		fallback_names: Vec<Cow<'static, str>>,
+		main_protocol_name: impl Into<ProtocolName>,
+		fallback_names: Vec<ProtocolName>,
 		initial_message: impl Into<Vec<u8>>,
 		max_notification_size: u64,
 	) -> Self {
@@ -351,27 +346,12 @@ impl NotificationsOut {
 	}
 }
 
-/// Implementation of the `ProtocolName` trait, where the protocol name is a string.
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct StringProtocolName(Cow<'static, str>);
-
-impl upgrade::ProtocolName for StringProtocolName {
-	fn protocol_name(&self) -> &[u8] {
-		self.0.as_bytes()
-	}
-}
-
 impl UpgradeInfo for NotificationsOut {
-	type Info = StringProtocolName;
+	type Info = ProtocolName;
 	type InfoIter = vec::IntoIter<Self::Info>;
 
 	fn protocol_info(&self) -> Self::InfoIter {
-		self.protocol_names
-			.iter()
-			.cloned()
-			.map(StringProtocolName)
-			.collect::<Vec<_>>()
-			.into_iter()
+		self.protocol_names.clone().into_iter()
 	}
 }
 
@@ -406,10 +386,10 @@ where
 
 			Ok(NotificationsOutOpen {
 				handshake,
-				negotiated_fallback: if negotiated_name.0 == self.protocol_names[0] {
+				negotiated_fallback: if negotiated_name == self.protocol_names[0] {
 					None
 				} else {
-					Some(negotiated_name.0)
+					Some(negotiated_name)
 				},
 				substream: NotificationsOutSubstream { socket: Framed::new(socket, codec) },
 			})
@@ -423,7 +403,7 @@ pub struct NotificationsOutOpen<TSubstream> {
 	pub handshake: Vec<u8>,
 	/// If the negotiated name is not the "main" protocol name but a fallback, contains the
 	/// name of the negotiated fallback.
-	pub negotiated_fallback: Option<Cow<'static, str>>,
+	pub negotiated_fallback: Option<ProtocolName>,
 	/// Implementation of `Sink` that allows sending messages on the substream.
 	pub substream: NotificationsOutSubstream<TSubstream>,
 }
@@ -505,11 +485,10 @@ mod tests {
 	use async_std::net::{TcpListener, TcpStream};
 	use futures::{channel::oneshot, prelude::*};
 	use libp2p::core::upgrade;
-	use std::borrow::Cow;
 
 	#[test]
 	fn basic_works() {
-		const PROTO_NAME: Cow<'static, str> = Cow::Borrowed("/test/proto/1");
+		const PROTO_NAME: &str = "/test/proto/1";
 		let (listener_addr_tx, listener_addr_rx) = oneshot::channel();
 
 		let client = async_std::task::spawn(async move {
@@ -552,7 +531,7 @@ mod tests {
 	fn empty_handshake() {
 		// Check that everything still works when the handshake messages are empty.
 
-		const PROTO_NAME: Cow<'static, str> = Cow::Borrowed("/test/proto/1");
+		const PROTO_NAME: &str = "/test/proto/1";
 		let (listener_addr_tx, listener_addr_rx) = oneshot::channel();
 
 		let client = async_std::task::spawn(async move {
@@ -593,7 +572,7 @@ mod tests {
 
 	#[test]
 	fn refused() {
-		const PROTO_NAME: Cow<'static, str> = Cow::Borrowed("/test/proto/1");
+		const PROTO_NAME: &str = "/test/proto/1";
 		let (listener_addr_tx, listener_addr_rx) = oneshot::channel();
 
 		let client = async_std::task::spawn(async move {
@@ -634,7 +613,7 @@ mod tests {
 
 	#[test]
 	fn large_initial_message_refused() {
-		const PROTO_NAME: Cow<'static, str> = Cow::Borrowed("/test/proto/1");
+		const PROTO_NAME: &str = "/test/proto/1";
 		let (listener_addr_tx, listener_addr_rx) = oneshot::channel();
 
 		let client = async_std::task::spawn(async move {
@@ -672,7 +651,7 @@ mod tests {
 
 	#[test]
 	fn large_handshake_refused() {
-		const PROTO_NAME: Cow<'static, str> = Cow::Borrowed("/test/proto/1");
+		const PROTO_NAME: &str = "/test/proto/1";
 		let (listener_addr_tx, listener_addr_rx) = oneshot::channel();
 
 		let client = async_std::task::spawn(async move {

substrate/client/network/src/request_responses.rs

@@ -50,11 +50,13 @@ use libp2p::{
 		NetworkBehaviourAction, PollParameters,
 	},
 };
-use sc_network_common::request_responses::{
-	IfDisconnected, IncomingRequest, OutgoingResponse, ProtocolConfig, RequestFailure,
+use sc_network_common::{
+	protocol::ProtocolName,
+	request_responses::{
+		IfDisconnected, IncomingRequest, OutgoingResponse, ProtocolConfig, RequestFailure,
+	},
 };
 use std::{
-	borrow::Cow,
 	collections::{hash_map::Entry, HashMap},
 	io, iter,
 	pin::Pin,
@@ -75,7 +77,7 @@ pub enum Event {
 		/// Peer which has emitted the request.
 		peer: PeerId,
 		/// Name of the protocol in question.
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		/// Whether handling the request was successful or unsuccessful.
 		///
 		/// When successful contains the time elapsed between when we received the request and when
@@ -91,7 +93,7 @@ pub enum Event {
 		/// Peer that we send a request to.
 		peer: PeerId,
 		/// Name of the protocol in question.
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		/// Duration the request took.
 		duration: Duration,
 		/// Result of the request.
@@ -110,12 +112,12 @@ pub enum Event {
 /// [`ProtocolRequestId`]s.
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 struct ProtocolRequestId {
-	protocol: Cow<'static, str>,
+	protocol: ProtocolName,
 	request_id: RequestId,
 }
 
-impl From<(Cow<'static, str>, RequestId)> for ProtocolRequestId {
-	fn from((protocol, request_id): (Cow<'static, str>, RequestId)) -> Self {
+impl From<(ProtocolName, RequestId)> for ProtocolRequestId {
+	fn from((protocol, request_id): (ProtocolName, RequestId)) -> Self {
 		Self { protocol, request_id }
 	}
 }
@@ -126,7 +128,7 @@ pub struct RequestResponsesBehaviour {
 	/// Contains the underlying libp2p `RequestResponse` behaviour, plus an optional
 	/// "response builder" used to build responses for incoming requests.
 	protocols: HashMap<
-		Cow<'static, str>,
+		ProtocolName,
 		(RequestResponse<GenericCodec>, Option<mpsc::Sender<IncomingRequest>>),
 	>,
 
@@ -162,7 +164,7 @@ struct MessageRequest {
 	request_id: RequestId,
 	request: Vec<u8>,
 	channel: ResponseChannel<Result<Vec<u8>, ()>>,
-	protocol: String,
+	protocol: ProtocolName,
 	resp_builder: Option<futures::channel::mpsc::Sender<IncomingRequest>>,
 	// Once we get incoming request we save all params, create an async call to Peerset
 	// to get the reputation of the peer.
@@ -173,7 +175,7 @@ struct MessageRequest {
 struct RequestProcessingOutcome {
 	peer: PeerId,
 	request_id: RequestId,
-	protocol: Cow<'static, str>,
+	protocol: ProtocolName,
 	inner_channel: ResponseChannel<Result<Vec<u8>, ()>>,
 	response: OutgoingResponse,
 }
@@ -495,7 +497,6 @@ impl NetworkBehaviour for RequestResponsesBehaviour {
 							debug_assert!(false, "Received message on outbound-only protocol.");
 						}
 
-						let protocol = Cow::from(protocol);
 						self.pending_responses.push(Box::pin(async move {
 							// The `tx` created above can be dropped if we are not capable of
 							// processing this request, which is reflected as a
@@ -618,7 +619,7 @@ impl NetworkBehaviour for RequestResponsesBehaviour {
 								request_id,
 								request,
 								channel,
-								protocol: protocol.to_string(),
+								protocol: protocol.clone(),
 								resp_builder: resp_builder.clone(),
 								get_peer_reputation,
 							});
@@ -766,7 +767,7 @@ impl NetworkBehaviour for RequestResponsesBehaviour {
 pub enum RegisterError {
 	/// A protocol has been specified multiple times.
 	#[error("{0}")]
-	DuplicateProtocol(Cow<'static, str>),
+	DuplicateProtocol(ProtocolName),
 }
 
 /// Error when processing a request sent by a remote.

substrate/client/network/src/service.rs

@@ -61,7 +61,10 @@ use parking_lot::Mutex;
 use sc_consensus::{BlockImportError, BlockImportStatus, ImportQueue, Link};
 use sc_network_common::{
 	config::MultiaddrWithPeerId,
-	protocol::event::{DhtEvent, Event},
+	protocol::{
+		event::{DhtEvent, Event},
+		ProtocolName,
+	},
 	request_responses::{IfDisconnected, RequestFailure},
 	service::{
 		NetworkDHTProvider, NetworkEventStream, NetworkNotification, NetworkPeers, NetworkSigner,
@@ -76,7 +79,6 @@ use sc_utils::mpsc::{tracing_unbounded, TracingUnboundedReceiver, TracingUnbound
 use sp_blockchain::HeaderBackend;
 use sp_runtime::traits::{Block as BlockT, NumberFor};
 use std::{
-	borrow::Cow,
 	cmp,
 	collections::{HashMap, HashSet},
 	fs, iter,
@@ -122,7 +124,7 @@ pub struct NetworkService<B: BlockT + 'static, H: ExHashT> {
 	to_worker: TracingUnboundedSender<ServiceToWorkerMsg<B, H>>,
 	/// For each peer and protocol combination, an object that allows sending notifications to
 	/// that peer. Updated by the [`NetworkWorker`].
-	peers_notifications_sinks: Arc<Mutex<HashMap<(PeerId, Cow<'static, str>), NotificationsSink>>>,
+	peers_notifications_sinks: Arc<Mutex<HashMap<(PeerId, ProtocolName), NotificationsSink>>>,
 	/// Field extracted from the [`Metrics`] struct and necessary to report the
 	/// notifications-related metrics.
 	notifications_sizes_metric: Option<HistogramVec>,
@@ -890,7 +892,7 @@ where
 		self.peerset.report_peer(who, cost_benefit);
 	}
 
-	fn disconnect_peer(&self, who: PeerId, protocol: Cow<'static, str>) {
+	fn disconnect_peer(&self, who: PeerId, protocol: ProtocolName) {
 		let _ = self.to_worker.unbounded_send(ServiceToWorkerMsg::DisconnectPeer(who, protocol));
 	}
 
@@ -921,7 +923,7 @@ where
 
 	fn set_reserved_peers(
 		&self,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		peers: HashSet<Multiaddr>,
 	) -> Result<(), String> {
 		let peers_addrs = self.split_multiaddr_and_peer_id(peers)?;
@@ -952,7 +954,7 @@ where
 
 	fn add_peers_to_reserved_set(
 		&self,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		peers: HashSet<Multiaddr>,
 	) -> Result<(), String> {
 		let peers = self.split_multiaddr_and_peer_id(peers)?;
@@ -976,7 +978,7 @@ where
 		Ok(())
 	}
 
-	fn remove_peers_from_reserved_set(&self, protocol: Cow<'static, str>, peers: Vec<PeerId>) {
+	fn remove_peers_from_reserved_set(&self, protocol: ProtocolName, peers: Vec<PeerId>) {
 		for peer_id in peers.into_iter() {
 			let _ = self
 				.to_worker
@@ -986,7 +988,7 @@ where
 
 	fn add_to_peers_set(
 		&self,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		peers: HashSet<Multiaddr>,
 	) -> Result<(), String> {
 		let peers = self.split_multiaddr_and_peer_id(peers)?;
@@ -1010,7 +1012,7 @@ where
 		Ok(())
 	}
 
-	fn remove_from_peers_set(&self, protocol: Cow<'static, str>, peers: Vec<PeerId>) {
+	fn remove_from_peers_set(&self, protocol: ProtocolName, peers: Vec<PeerId>) {
 		for peer_id in peers.into_iter() {
 			let _ = self
 				.to_worker
@@ -1040,7 +1042,7 @@ where
 	B: BlockT + 'static,
 	H: ExHashT,
 {
-	fn write_notification(&self, target: PeerId, protocol: Cow<'static, str>, message: Vec<u8>) {
+	fn write_notification(&self, target: PeerId, protocol: ProtocolName, message: Vec<u8>) {
 		// We clone the `NotificationsSink` in order to be able to unlock the network-wide
 		// `peers_notifications_sinks` mutex as soon as possible.
 		let sink = {
@@ -1077,7 +1079,7 @@ where
 	fn notification_sender(
 		&self,
 		target: PeerId,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 	) -> Result<Box<dyn NotificationSenderT>, NotificationSenderError> {
 		// We clone the `NotificationsSink` in order to be able to unlock the network-wide
 		// `peers_notifications_sinks` mutex as soon as possible.
@@ -1108,7 +1110,7 @@ where
 	async fn request(
 		&self,
 		target: PeerId,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		request: Vec<u8>,
 		connect: IfDisconnected,
 	) -> Result<Vec<u8>, RequestFailure> {
@@ -1128,7 +1130,7 @@ where
 	fn start_request(
 		&self,
 		target: PeerId,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		request: Vec<u8>,
 		tx: oneshot::Sender<Result<Vec<u8>, RequestFailure>>,
 		connect: IfDisconnected,
@@ -1179,7 +1181,7 @@ pub struct NotificationSender {
 	sink: NotificationsSink,
 
 	/// Name of the protocol on the wire.
-	protocol_name: Cow<'static, str>,
+	protocol_name: ProtocolName,
 
 	/// Field extracted from the [`Metrics`] struct and necessary to report the
 	/// notifications-related metrics.
@@ -1212,7 +1214,7 @@ pub struct NotificationSenderReady<'a> {
 	peer_id: &'a PeerId,
 
 	/// Name of the protocol on the wire.
-	protocol_name: &'a Cow<'static, str>,
+	protocol_name: &'a ProtocolName,
 
 	/// Field extracted from the [`Metrics`] struct and necessary to report the
 	/// notifications-related metrics.
@@ -1256,16 +1258,16 @@ enum ServiceToWorkerMsg<B: BlockT, H: ExHashT> {
 	AddReserved(PeerId),
 	RemoveReserved(PeerId),
 	SetReserved(HashSet<PeerId>),
-	SetPeersetReserved(Cow<'static, str>, HashSet<PeerId>),
-	AddSetReserved(Cow<'static, str>, PeerId),
-	RemoveSetReserved(Cow<'static, str>, PeerId),
-	AddToPeersSet(Cow<'static, str>, PeerId),
-	RemoveFromPeersSet(Cow<'static, str>, PeerId),
+	SetPeersetReserved(ProtocolName, HashSet<PeerId>),
+	AddSetReserved(ProtocolName, PeerId),
+	RemoveSetReserved(ProtocolName, PeerId),
+	AddToPeersSet(ProtocolName, PeerId),
+	RemoveFromPeersSet(ProtocolName, PeerId),
 	SyncFork(Vec<PeerId>, B::Hash, NumberFor<B>),
 	EventStream(out_events::Sender),
 	Request {
 		target: PeerId,
-		protocol: Cow<'static, str>,
+		protocol: ProtocolName,
 		request: Vec<u8>,
 		pending_response: oneshot::Sender<Result<Vec<u8>, RequestFailure>>,
 		connect: IfDisconnected,
@@ -1276,7 +1278,7 @@ enum ServiceToWorkerMsg<B: BlockT, H: ExHashT> {
 	NetworkState {
 		pending_response: oneshot::Sender<Result<NetworkState, RequestFailure>>,
 	},
-	DisconnectPeer(PeerId, Cow<'static, str>),
+	DisconnectPeer(PeerId, ProtocolName),
 	NewBestBlockImported(B::Hash, NumberFor<B>),
 }
 
@@ -1312,7 +1314,7 @@ where
 	boot_node_ids: Arc<HashSet<PeerId>>,
 	/// For each peer and protocol combination, an object that allows sending notifications to
 	/// that peer. Shared with the [`NetworkService`].
-	peers_notifications_sinks: Arc<Mutex<HashMap<(PeerId, Cow<'static, str>), NotificationsSink>>>,
+	peers_notifications_sinks: Arc<Mutex<HashMap<(PeerId, ProtocolName), NotificationsSink>>>,
 	/// Controller for the handler of incoming and outgoing transactions.
 	tx_handler_controller: transactions::TransactionsHandlerController<H>,
 }
@@ -1456,7 +1458,7 @@ where
 					.network_service
 					.behaviour_mut()
 					.user_protocol_mut()
-					.disconnect_peer(&who, &protocol_name),
+					.disconnect_peer(&who, protocol_name),
 				ServiceToWorkerMsg::NewBestBlockImported(hash, number) => this
 					.network_service
 					.behaviour_mut()

substrate/client/network/src/service/tests.rs

@@ -32,7 +32,7 @@ use sc_network_sync::{
 };
 use sp_consensus::block_validation::DefaultBlockAnnounceValidator;
 use sp_runtime::traits::{Block as BlockT, Header as _};
-use std::{borrow::Cow, sync::Arc, time::Duration};
+use std::{sync::Arc, time::Duration};
 use substrate_test_runtime_client::{TestClientBuilder, TestClientBuilderExt as _};
 
 type TestNetworkService = NetworkService<
@@ -165,7 +165,7 @@ fn build_test_full_node(
 	(service, event_stream)
 }
 
-const PROTOCOL_NAME: Cow<'static, str> = Cow::Borrowed("/foo");
+const PROTOCOL_NAME: &str = "/foo";
 
 /// Builds two nodes and their associated events stream.
 /// The nodes are connected together and have the `PROTOCOL_NAME` protocol registered.
@@ -179,7 +179,7 @@ fn build_nodes_one_proto() -> (
 
 	let (node1, events_stream1) = build_test_full_node(config::NetworkConfiguration {
 		extra_sets: vec![config::NonDefaultSetConfig {
-			notifications_protocol: PROTOCOL_NAME,
+			notifications_protocol: PROTOCOL_NAME.into(),
 			fallback_names: Vec::new(),
 			max_notification_size: 1024 * 1024,
 			set_config: Default::default(),
@@ -191,7 +191,7 @@ fn build_nodes_one_proto() -> (
 
 	let (node2, events_stream2) = build_test_full_node(config::NetworkConfiguration {
 		extra_sets: vec![config::NonDefaultSetConfig {
-			notifications_protocol: PROTOCOL_NAME,
+			notifications_protocol: PROTOCOL_NAME.into(),
 			fallback_names: Vec::new(),
 			max_notification_size: 1024 * 1024,
 			set_config: config::SetConfig {
@@ -219,10 +219,18 @@ fn notifications_state_consistent() {
 
 	// Write some initial notifications that shouldn't get through.
 	for _ in 0..(rand::random::<u8>() % 5) {
-		node1.write_notification(node2.local_peer_id(), PROTOCOL_NAME, b"hello world".to_vec());
+		node1.write_notification(
+			node2.local_peer_id(),
+			PROTOCOL_NAME.into(),
+			b"hello world".to_vec(),
+		);
 	}
 	for _ in 0..(rand::random::<u8>() % 5) {
-		node2.write_notification(node1.local_peer_id(), PROTOCOL_NAME, b"hello world".to_vec());
+		node2.write_notification(
+			node1.local_peer_id(),
+			PROTOCOL_NAME.into(),
+			b"hello world".to_vec(),
+		);
 	}
 
 	async_std::task::block_on(async move {
@@ -247,24 +255,24 @@ fn notifications_state_consistent() {
 			if rand::random::<u8>() % 5 >= 3 {
 				node1.write_notification(
 					node2.local_peer_id(),
-					PROTOCOL_NAME,
+					PROTOCOL_NAME.into(),
 					b"hello world".to_vec(),
 				);
 			}
 			if rand::random::<u8>() % 5 >= 3 {
 				node2.write_notification(
 					node1.local_peer_id(),
-					PROTOCOL_NAME,
+					PROTOCOL_NAME.into(),
 					b"hello world".to_vec(),
 				);
 			}
 
 			// Also randomly disconnect the two nodes from time to time.
 			if rand::random::<u8>() % 20 == 0 {
-				node1.disconnect_peer(node2.local_peer_id(), PROTOCOL_NAME);
+				node1.disconnect_peer(node2.local_peer_id(), PROTOCOL_NAME.into());
 			}
 			if rand::random::<u8>() % 20 == 0 {
-				node2.disconnect_peer(node1.local_peer_id(), PROTOCOL_NAME);
+				node2.disconnect_peer(node1.local_peer_id(), PROTOCOL_NAME.into());
 			}
 
 			// Grab next event from either `events_stream1` or `events_stream2`.
@@ -288,7 +296,7 @@ fn notifications_state_consistent() {
 				future::Either::Left(Event::NotificationStreamOpened {
 					remote, protocol, ..
 				}) =>
-					if protocol == PROTOCOL_NAME {
+					if protocol == PROTOCOL_NAME.into() {
 						something_happened = true;
 						assert!(!node1_to_node2_open);
 						node1_to_node2_open = true;
@@ -297,7 +305,7 @@ fn notifications_state_consistent() {
 				future::Either::Right(Event::NotificationStreamOpened {
 					remote, protocol, ..
 				}) =>
-					if protocol == PROTOCOL_NAME {
+					if protocol == PROTOCOL_NAME.into() {
 						something_happened = true;
 						assert!(!node2_to_node1_open);
 						node2_to_node1_open = true;
@@ -306,7 +314,7 @@ fn notifications_state_consistent() {
 				future::Either::Left(Event::NotificationStreamClosed {
 					remote, protocol, ..
 				}) =>
-					if protocol == PROTOCOL_NAME {
+					if protocol == PROTOCOL_NAME.into() {
 						assert!(node1_to_node2_open);
 						node1_to_node2_open = false;
 						assert_eq!(remote, node2.local_peer_id());
@@ -314,7 +322,7 @@ fn notifications_state_consistent() {
 				future::Either::Right(Event::NotificationStreamClosed {
 					remote, protocol, ..
 				}) =>
-					if protocol == PROTOCOL_NAME {
+					if protocol == PROTOCOL_NAME.into() {
 						assert!(node2_to_node1_open);
 						node2_to_node1_open = false;
 						assert_eq!(remote, node1.local_peer_id());
@@ -325,7 +333,7 @@ fn notifications_state_consistent() {
 					if rand::random::<u8>() % 5 >= 4 {
 						node1.write_notification(
 							node2.local_peer_id(),
-							PROTOCOL_NAME,
+							PROTOCOL_NAME.into(),
 							b"hello world".to_vec(),
 						);
 					}
@@ -336,7 +344,7 @@ fn notifications_state_consistent() {
 					if rand::random::<u8>() % 5 >= 4 {
 						node2.write_notification(
 							node1.local_peer_id(),
-							PROTOCOL_NAME,
+							PROTOCOL_NAME.into(),
 							b"hello world".to_vec(),
 						);
 					}
@@ -361,7 +369,7 @@ fn lots_of_incoming_peers_works() {
 	let (main_node, _) = build_test_full_node(config::NetworkConfiguration {
 		listen_addresses: vec![listen_addr.clone()],
 		extra_sets: vec![config::NonDefaultSetConfig {
-			notifications_protocol: PROTOCOL_NAME,
+			notifications_protocol: PROTOCOL_NAME.into(),
 			fallback_names: Vec::new(),
 			max_notification_size: 1024 * 1024,
 			set_config: config::SetConfig { in_peers: u32::MAX, ..Default::default() },
@@ -380,7 +388,7 @@ fn lots_of_incoming_peers_works() {
 		let (_dialing_node, event_stream) = build_test_full_node(config::NetworkConfiguration {
 			listen_addresses: vec![],
 			extra_sets: vec![config::NonDefaultSetConfig {
-				notifications_protocol: PROTOCOL_NAME,
+				notifications_protocol: PROTOCOL_NAME.into(),
 				fallback_names: Vec::new(),
 				max_notification_size: 1024 * 1024,
 				set_config: config::SetConfig {
@@ -449,7 +457,7 @@ fn notifications_back_pressure() {
 				Event::NotificationStreamClosed { .. } => panic!(),
 				Event::NotificationsReceived { messages, .. } =>
 					for message in messages {
-						assert_eq!(message.0, PROTOCOL_NAME);
+						assert_eq!(message.0, PROTOCOL_NAME.into());
 						assert_eq!(message.1, format!("hello #{}", received_notifications));
 						received_notifications += 1;
 					},
@@ -473,7 +481,7 @@ fn notifications_back_pressure() {
 
 		// Sending!
 		for num in 0..TOTAL_NOTIFS {
-			let notif = node1.notification_sender(node2_id, PROTOCOL_NAME).unwrap();
+			let notif = node1.notification_sender(node2_id, PROTOCOL_NAME.into()).unwrap();
 			notif
 				.ready()
 				.await
@@ -491,15 +499,14 @@ fn fallback_name_working() {
 	// Node 1 supports the protocols "new" and "old". Node 2 only supports "old". Checks whether
 	// they can connect.
 
-	const NEW_PROTOCOL_NAME: Cow<'static, str> =
-		Cow::Borrowed("/new-shiny-protocol-that-isnt-PROTOCOL_NAME");
+	const NEW_PROTOCOL_NAME: &str = "/new-shiny-protocol-that-isnt-PROTOCOL_NAME";
 
 	let listen_addr = config::build_multiaddr![Memory(rand::random::<u64>())];
 
 	let (node1, mut events_stream1) = build_test_full_node(config::NetworkConfiguration {
 		extra_sets: vec![config::NonDefaultSetConfig {
-			notifications_protocol: NEW_PROTOCOL_NAME.clone(),
-			fallback_names: vec![PROTOCOL_NAME],
+			notifications_protocol: NEW_PROTOCOL_NAME.into(),
+			fallback_names: vec![PROTOCOL_NAME.into()],
 			max_notification_size: 1024 * 1024,
 			set_config: Default::default(),
 		}],
@@ -510,7 +517,7 @@ fn fallback_name_working() {
 
 	let (_, mut events_stream2) = build_test_full_node(config::NetworkConfiguration {
 		extra_sets: vec![config::NonDefaultSetConfig {
-			notifications_protocol: PROTOCOL_NAME,
+			notifications_protocol: PROTOCOL_NAME.into(),
 			fallback_names: Vec::new(),
 			max_notification_size: 1024 * 1024,
 			set_config: config::SetConfig {
@@ -531,7 +538,7 @@ fn fallback_name_working() {
 		loop {
 			match events_stream2.next().await.unwrap() {
 				Event::NotificationStreamOpened { protocol, negotiated_fallback, .. } => {
-					assert_eq!(protocol, PROTOCOL_NAME);
+					assert_eq!(protocol, PROTOCOL_NAME.into());
 					assert_eq!(negotiated_fallback, None);
 					break
 				},
@@ -545,9 +552,9 @@ fn fallback_name_working() {
 		loop {
 			match events_stream1.next().await.unwrap() {
 				Event::NotificationStreamOpened { protocol, negotiated_fallback, .. }
-					if protocol == NEW_PROTOCOL_NAME =>
+					if protocol == NEW_PROTOCOL_NAME.into() =>
 				{
-					assert_eq!(negotiated_fallback, Some(PROTOCOL_NAME));
+					assert_eq!(negotiated_fallback, Some(PROTOCOL_NAME.into()));
 					break
 				},
 				_ => {},

substrate/client/network/src/transactions.rs

@@ -42,12 +42,14 @@ use log::{debug, trace, warn};
 use prometheus_endpoint::{register, Counter, PrometheusError, Registry, U64};
 use sc_network_common::{
 	config::ProtocolId,
-	protocol::event::{Event, ObservedRole},
+	protocol::{
+		event::{Event, ObservedRole},
+		ProtocolName,
+	},
 	service::{NetworkEventStream, NetworkNotification, NetworkPeers},
 };
 use sp_runtime::traits::Block as BlockT;
 use std::{
-	borrow::Cow,
 	collections::{hash_map::Entry, HashMap},
 	iter,
 	num::NonZeroUsize,
@@ -130,8 +132,8 @@ impl<H: ExHashT> Future for PendingTransaction<H> {
 
 /// Prototype for a [`TransactionsHandler`].
 pub struct TransactionsHandlerPrototype {
-	protocol_name: Cow<'static, str>,
-	fallback_protocol_names: Vec<Cow<'static, str>>,
+	protocol_name: ProtocolName,
+	fallback_protocol_names: Vec<ProtocolName>,
 }
 
 impl TransactionsHandlerPrototype {
@@ -244,7 +246,7 @@ enum ToHandler<H: ExHashT> {
 
 /// Handler for transactions. Call [`TransactionsHandler::run`] to start the processing.
 pub struct TransactionsHandler<B: BlockT + 'static, H: ExHashT> {
-	protocol_name: Cow<'static, str>,
+	protocol_name: ProtocolName,
 	/// Interval at which we call `propagate_transactions`.
 	propagate_timeout: Pin<Box<dyn Stream<Item = ()> + Send>>,
 	/// Pending transactions verification tasks.

substrate/client/network/test/src/lib.rs

@@ -23,7 +23,6 @@ mod block_import;
 mod sync;
 
 use std::{
-	borrow::Cow,
 	collections::HashMap,
 	marker::PhantomData,
 	pin::Pin,
@@ -58,6 +57,7 @@ use sc_network::{
 };
 use sc_network_common::{
 	config::{MultiaddrWithPeerId, ProtocolId},
+	protocol::ProtocolName,
 	service::{NetworkBlock, NetworkStateInfo, NetworkSyncForkRequest},
 	sync::warp::{AuthorityList, EncodedProof, SetId, VerificationResult, WarpSyncProvider},
 };
@@ -682,7 +682,7 @@ pub struct FullPeerConfig {
 	/// Block announce validator.
 	pub block_announce_validator: Option<Box<dyn BlockAnnounceValidator<Block> + Send + Sync>>,
 	/// List of notification protocols that the network must support.
-	pub notifications_protocols: Vec<Cow<'static, str>>,
+	pub notifications_protocols: Vec<ProtocolName>,
 	/// The indices of the peers the peer should be connected to.
 	///
 	/// If `None`, it will be connected to all other peers.

substrate/client/offchain/src/api.rs

@@ -328,11 +328,12 @@ mod tests {
 	use sc_client_db::offchain::LocalStorage;
 	use sc_network_common::{
 		config::MultiaddrWithPeerId,
+		protocol::ProtocolName,
 		service::{NetworkPeers, NetworkStateInfo},
 	};
 	use sc_peerset::ReputationChange;
 	use sp_core::offchain::{DbExternalities, Externalities};
-	use std::{borrow::Cow, time::SystemTime};
+	use std::time::SystemTime;
 
 	pub(super) struct TestNetwork();
 
@@ -353,7 +354,7 @@ mod tests {
 			unimplemented!();
 		}
 
-		fn disconnect_peer(&self, _who: PeerId, _protocol: Cow<'static, str>) {
+		fn disconnect_peer(&self, _who: PeerId, _protocol: ProtocolName) {
 			unimplemented!();
 		}
 
@@ -375,7 +376,7 @@ mod tests {
 
 		fn set_reserved_peers(
 			&self,
-			_protocol: Cow<'static, str>,
+			_protocol: ProtocolName,
 			_peers: HashSet<Multiaddr>,
 		) -> Result<(), String> {
 			unimplemented!();
@@ -383,29 +384,25 @@ mod tests {
 
 		fn add_peers_to_reserved_set(
 			&self,
-			_protocol: Cow<'static, str>,
+			_protocol: ProtocolName,
 			_peers: HashSet<Multiaddr>,
 		) -> Result<(), String> {
 			unimplemented!();
 		}
 
-		fn remove_peers_from_reserved_set(
-			&self,
-			_protocol: Cow<'static, str>,
-			_peers: Vec<PeerId>,
-		) {
+		fn remove_peers_from_reserved_set(&self, _protocol: ProtocolName, _peers: Vec<PeerId>) {
 			unimplemented!();
 		}
 
 		fn add_to_peers_set(
 			&self,
-			_protocol: Cow<'static, str>,
+			_protocol: ProtocolName,
 			_peers: HashSet<Multiaddr>,
 		) -> Result<(), String> {
 			unimplemented!();
 		}
 
-		fn remove_from_peers_set(&self, _protocol: Cow<'static, str>, _peers: Vec<PeerId>) {
+		fn remove_from_peers_set(&self, _protocol: ProtocolName, _peers: Vec<PeerId>) {
 			unimplemented!();
 		}
 

substrate/client/offchain/src/lib.rs

@@ -249,12 +249,12 @@ mod tests {
 	use libp2p::{Multiaddr, PeerId};
 	use sc_block_builder::BlockBuilderProvider as _;
 	use sc_client_api::Backend as _;
-	use sc_network_common::config::MultiaddrWithPeerId;
+	use sc_network_common::{config::MultiaddrWithPeerId, protocol::ProtocolName};
 	use sc_peerset::ReputationChange;
 	use sc_transaction_pool::{BasicPool, FullChainApi};
 	use sc_transaction_pool_api::{InPoolTransaction, TransactionPool};
 	use sp_consensus::BlockOrigin;
-	use std::{borrow::Cow, collections::HashSet, sync::Arc};
+	use std::{collections::HashSet, sync::Arc};
 	use substrate_test_runtime_client::{
 		runtime::Block, ClientBlockImportExt, DefaultTestClientBuilderExt, TestClient,
 		TestClientBuilderExt,
@@ -289,7 +289,7 @@ mod tests {
 			unimplemented!();
 		}
 
-		fn disconnect_peer(&self, _who: PeerId, _protocol: Cow<'static, str>) {
+		fn disconnect_peer(&self, _who: PeerId, _protocol: ProtocolName) {
 			unimplemented!();
 		}
 
@@ -311,7 +311,7 @@ mod tests {
 
 		fn set_reserved_peers(
 			&self,
-			_protocol: Cow<'static, str>,
+			_protocol: ProtocolName,
 			_peers: HashSet<Multiaddr>,
 		) -> Result<(), String> {
 			unimplemented!();
@@ -319,29 +319,25 @@ mod tests {
 
 		fn add_peers_to_reserved_set(
 			&self,
-			_protocol: Cow<'static, str>,
+			_protocol: ProtocolName,
 			_peers: HashSet<Multiaddr>,
 		) -> Result<(), String> {
 			unimplemented!();
 		}
 
-		fn remove_peers_from_reserved_set(
-			&self,
-			_protocol: Cow<'static, str>,
-			_peers: Vec<PeerId>,
-		) {
+		fn remove_peers_from_reserved_set(&self, _protocol: ProtocolName, _peers: Vec<PeerId>) {
 			unimplemented!();
 		}
 
 		fn add_to_peers_set(
 			&self,
-			_protocol: Cow<'static, str>,
+			_protocol: ProtocolName,
 			_peers: HashSet<Multiaddr>,
 		) -> Result<(), String> {
 			unimplemented!();
 		}
 
-		fn remove_from_peers_set(&self, _protocol: Cow<'static, str>, _peers: Vec<PeerId>) {
+		fn remove_from_peers_set(&self, _protocol: ProtocolName, _peers: Vec<PeerId>) {
 			unimplemented!();
 		}