rpc servers CLI: add --max--subscriptions--per--connection + fix a few bugs (#11461)

* cli: fix RPC CLI nits

* remove needless lines

* cargo fmt

* Update client/service/src/lib.rs

Co-authored-by: James Wilson <james@jsdw.me>

Co-authored-by: James Wilson <james@jsdw.me>

substrate/client/cli/src/commands/run_cmd.rs

@@ -115,6 +115,11 @@ pub struct RunCmd {
 	#[clap(long)]
 	pub rpc_max_response_size: Option<usize>,
 
+	/// Set the the maximum concurrent subscriptions per connection.
+	/// Default is 1024.
+	#[clap(long)]
+	pub rpc_max_subscriptions_per_connection: Option<usize>,
+
 	/// Expose Prometheus exporter on all interfaces.
 	///
 	/// Default is local.
@@ -459,6 +464,18 @@ impl CliConfiguration for RunCmd {
 		Ok(self.rpc_max_payload)
 	}
 
+	fn rpc_max_request_size(&self) -> Result<Option<usize>> {
+		Ok(self.rpc_max_request_size)
+	}
+
+	fn rpc_max_response_size(&self) -> Result<Option<usize>> {
+		Ok(self.rpc_max_response_size)
+	}
+
+	fn rpc_max_subscriptions_per_connection(&self) -> Result<Option<usize>> {
+		Ok(self.rpc_max_subscriptions_per_connection)
+	}
+
 	fn ws_max_out_buffer_capacity(&self) -> Result<Option<usize>> {
 		Ok(self.ws_max_out_buffer_capacity)
 	}

substrate/client/cli/src/config.rs

@@ -369,6 +369,11 @@ pub trait CliConfiguration<DCV: DefaultConfigurationValues = ()>: Sized {
 		Ok(None)
 	}
 
+	/// Get maximum number of subscriptions per connection.
+	fn rpc_max_subscriptions_per_connection(&self) -> Result<Option<usize>> {
+		Ok(None)
+	}
+
 	/// Get maximum WS output buffer capacity.
 	fn ws_max_out_buffer_capacity(&self) -> Result<Option<usize>> {
 		Ok(None)
@@ -539,7 +544,7 @@ pub trait CliConfiguration<DCV: DefaultConfigurationValues = ()>: Sized {
 			rpc_max_request_size: self.rpc_max_request_size()?,
 			rpc_max_response_size: self.rpc_max_response_size()?,
 			rpc_id_provider: None,
-			rpc_max_subs_per_conn: None,
+			rpc_max_subs_per_conn: self.rpc_max_subscriptions_per_connection()?,
 			ws_max_out_buffer_capacity: self.ws_max_out_buffer_capacity()?,
 			prometheus_config: self
 				.prometheus_config(DCV::prometheus_listen_port(), &chain_spec)?,

substrate/client/service/src/lib.rs

@@ -480,11 +480,18 @@ where
 }
 
 fn legacy_cli_parsing(config: &Configuration) -> (Option<usize>, Option<usize>, Option<usize>) {
-	let ws_max_response_size = config.ws_max_out_buffer_capacity.map(|max| {
+	let ws_max_response_size = match (
-		eprintln!("DEPRECATED: `--ws_max_out_buffer_capacity` has been removed use `rpc-max-response-size or rpc-max-request-size` instead");
+		config.ws_max_out_buffer_capacity,
-		eprintln!("Setting WS `rpc-max-response-size` to `max(ws_max_out_buffer_capacity, rpc_max_response_size)`");
+		config.rpc_max_response_size,
-		std::cmp::max(max, config.rpc_max_response_size.unwrap_or(0))
+	) {
-	});
+		(Some(legacy_max), max) => {
+			eprintln!("DEPRECATED: `--ws_max_out_buffer_capacity` has been removed; use `rpc-max-response-size or rpc-max-request-size` instead");
+			eprintln!("Setting WS `rpc-max-response-size` to `max(ws_max_out_buffer_capacity, rpc_max_response_size)`");
+			Some(std::cmp::max(legacy_max, max.unwrap_or(0)))
+		},
+		(None, Some(m)) => Some(m),
+		(None, None) => None,
+	};
 
 	let max_request_size = match (config.rpc_max_payload, config.rpc_max_request_size) {
 		(Some(legacy_max), max) => {
@@ -498,7 +505,7 @@ fn legacy_cli_parsing(config: &Configuration) -> (Option<usize>, Option<usize>,
 		(None, None) => None,
 	};
 
-	let http_max_response_size = match (config.rpc_max_payload, config.rpc_max_request_size) {
+	let http_max_response_size = match (config.rpc_max_payload, config.rpc_max_response_size) {
 		(Some(legacy_max), max) => {
 			eprintln!("DEPRECATED: `--rpc_max_payload` has been removed use `rpc-max-response-size or rpc-max-request-size` instead");
 			eprintln!(