From 188a103e203d1fa0ad8661b076bc0b47f913c36c Mon Sep 17 00:00:00 2001
From: Cecile Tonglet <cecile@parity.io>
Date: Thu, 27 Feb 2020 16:18:38 +0100
Subject: [PATCH] Spawn a future to start the collator (#851)

* Running a node without a database set in config is a bug, not a user error
---
 polkadot/collator/src/lib.rs | 58 +++++++++++++++++++++++++++++++-----
 polkadot/service/src/lib.rs  |  2 +-
 2 files changed, 52 insertions(+), 8 deletions(-)

diff --git a/polkadot/collator/src/lib.rs b/polkadot/collator/src/lib.rs
index e0f230452c..7dc4f70d20 100644
--- a/polkadot/collator/src/lib.rs
+++ b/polkadot/collator/src/lib.rs
@@ -217,8 +217,7 @@ pub async fn collate<P>(
 	Ok(collation)
 }
 
-/// Run the collator node using the given `service`.
-fn run_collator_node<S, P, Extrinsic>(
+fn build_collator_service<S, P, Extrinsic>(
 	service: S,
 	para_id: ParaId,
 	key: Arc<CollatorPair>,
@@ -381,6 +380,51 @@ fn run_collator_node<S, P, Extrinsic>(
 	Ok(service)
 }
 
+/// Async function that will run the collator node with the given `RelayChainContext` and `ParachainContext`
+/// built by the given `BuildParachainContext` and arguments to the underlying polkadot node.
+pub async fn start_collator<P>(
+	build_parachain_context: P,
+	para_id: ParaId,
+	key: Arc<CollatorPair>,
+	config: Configuration,
+) -> Result<(), polkadot_service::Error>
+where
+	P: BuildParachainContext,
+	P::ParachainContext: Send + 'static,
+	<P::ParachainContext as ParachainContext>::ProduceCandidate: Send,
+{
+	match (config.expect_chain_spec().is_kusama(), config.roles) {
+		(true, Roles::LIGHT) =>
+			build_collator_service(
+				service::kusama_new_light(config, Some((key.public(), para_id)))?,
+				para_id,
+				key,
+				build_parachain_context,
+			)?.await,
+		(true, _) =>
+			build_collator_service(
+				service::kusama_new_full(config, Some((key.public(), para_id)), None, false, 6000)?,
+				para_id,
+				key,
+				build_parachain_context,
+			)?.await,
+		(false, Roles::LIGHT) =>
+			build_collator_service(
+				service::polkadot_new_light(config, Some((key.public(), para_id)))?,
+				para_id,
+				key,
+				build_parachain_context,
+			)?.await,
+		(false, _) =>
+			build_collator_service(
+				service::polkadot_new_full(config, Some((key.public(), para_id)), None, false, 6000)?,
+				para_id,
+				key,
+				build_parachain_context,
+			)?.await,
+	}
+}
+
 fn compute_targets(para_id: ParaId, session_keys: &[ValidatorId], roster: DutyRoster) -> HashSet<ValidatorId> {
 	use polkadot_primitives::parachain::Chain;
 
@@ -392,7 +436,7 @@ fn compute_targets(para_id: ParaId, session_keys: &[ValidatorId], roster: DutyRo
 }
 
 /// Run a collator node with the given `RelayChainContext` and `ParachainContext`
-/// build by the given `BuildParachainContext` and arguments to the underlying polkadot node.
+/// built by the given `BuildParachainContext` and arguments to the underlying polkadot node.
 ///
 /// This function blocks until done.
 pub fn run_collator<P>(
@@ -408,7 +452,7 @@ pub fn run_collator<P>(
 	match (config.expect_chain_spec().is_kusama(), config.roles) {
 		(true, Roles::LIGHT) =>
 			sc_cli::run_service_until_exit(config, |config| {
-				run_collator_node(
+				build_collator_service(
 					service::kusama_new_light(config, Some((key.public(), para_id)))?,
 					para_id,
 					key,
@@ -417,7 +461,7 @@ pub fn run_collator<P>(
 			}),
 		(true, _) =>
 			sc_cli::run_service_until_exit(config, |config| {
-				run_collator_node(
+				build_collator_service(
 					service::kusama_new_full(config, Some((key.public(), para_id)), None, false, 6000)?,
 					para_id,
 					key,
@@ -426,7 +470,7 @@ pub fn run_collator<P>(
 			}),
 		(false, Roles::LIGHT) =>
 			sc_cli::run_service_until_exit(config, |config| {
-				run_collator_node(
+				build_collator_service(
 					service::polkadot_new_light(config, Some((key.public(), para_id)))?,
 					para_id,
 					key,
@@ -435,7 +479,7 @@ pub fn run_collator<P>(
 			}),
 		(false, _) =>
 			sc_cli::run_service_until_exit(config, |config| {
-				run_collator_node(
+				build_collator_service(
 					service::polkadot_new_full(config, Some((key.public(), para_id)), None, false, 6000)?,
 					para_id,
 					key,
diff --git a/polkadot/service/src/lib.rs b/polkadot/service/src/lib.rs
index 2a2db82cb4..ee64465f69 100644
--- a/polkadot/service/src/lib.rs
+++ b/polkadot/service/src/lib.rs
@@ -272,7 +272,7 @@ pub fn new_full<Runtime, Dispatch, Extrinsic>(
 	let is_authority = config.roles.is_authority() && !is_collator;
 	let force_authoring = config.force_authoring;
 	let max_block_data_size = max_block_data_size;
-	let db_path = if let Some(DatabaseConfig::Path { ref path, .. }) = config.database {
+	let db_path = if let DatabaseConfig::Path { ref path, .. } = config.expect_database() {
 		path.clone()
 	} else {
 		return Err("Starting a Polkadot service with a custom database isn't supported".to_string().into());