Add cli param to limit database cache size (#1261)

* Add cli param to limit datbase cache size

* fixing tests

substrate/core/cli/src/lib.rs

@@ -228,7 +228,10 @@ where
 		.into();
 
 	config.database_path = db_path(&base_path, config.chain_spec.id()).to_string_lossy().into();
-
+	config.database_cache_size = match matches.value_of("database_cache_size") {
+		Some(s) => Some(s.parse().map_err(|_| "Invalid Database Cache size specified")?),
+		_=> None
+	};
 	config.pruning = match matches.value_of("pruning") {
 		Some("archive") => PruningMode::ArchiveAll,
 		None => PruningMode::default(),

substrate/core/cli/src/params.rs

@@ -45,6 +45,10 @@ pub struct CoreParams {
 	#[structopt(long = "light")]
 	light: bool,
 
+	/// Limit the memory the database cache can use
+	#[structopt(long = "db-cache", value_name = "MiB")]
+	database_cache_size: Option<u32>,
+
 	/// Listen on this multiaddress
 	#[structopt(long = "listen-addr", value_name = "LISTEN_ADDR")]
 	listen_addr: Vec<String>,

substrate/core/service/src/components.rs

@@ -415,7 +415,7 @@ impl<Factory: ServiceFactory> Components for FullComponents<Factory> {
 		), error::Error>
 	{
 		let db_settings = client_db::DatabaseSettings {
-			cache_size: None,
+			cache_size: config.database_cache_size.map(|u| u as usize),
 			path: config.database_path.as_str().into(),
 			pruning: config.pruning.clone(),
 		};

substrate/core/service/src/config.rs

@@ -45,6 +45,8 @@ pub struct Configuration<C, G: Serialize + DeserializeOwned + BuildStorage> {
 	pub keystore_path: String,
 	/// Path to the database.
 	pub database_path: String,
+	/// Cache Size for internal database in MiB
+	pub database_cache_size: Option<u32>,
 	/// Pruning settings.
 	pub pruning: PruningMode,
 	/// Additional key seeds.
@@ -81,6 +83,7 @@ impl<C: Default, G: Serialize + DeserializeOwned + BuildStorage> Configuration<C
 			network: Default::default(),
 			keystore_path: Default::default(),
 			database_path: Default::default(),
+			database_cache_size: Default::default(),
 			keys: Default::default(),
 			custom: Default::default(),
 			pruning: PruningMode::default(),

substrate/core/service/test/src/lib.rs

@@ -123,6 +123,7 @@ fn node_config<F: ServiceFactory> (
 		network: network_config,
 		keystore_path: root.join("key").to_str().unwrap().into(),
 		database_path: root.join("db").to_str().unwrap().into(),
+		database_cache_size: None,
 		pruning: Default::default(),
 		keys: keys,
 		chain_spec: (*spec).clone(),