Drop sc-client (#1037)

* WIP

* collator

* fix missing reference

* Make collator builder more generic

* all clear

* revert start colator fn

* fix return type of start_collator

* sc-consensus

* bump back to master

* Update collator/src/lib.rs

Co-Authored-By: Benjamin Kampmann <ben@gnunicorn.org>

* Update collator/src/lib.rs

Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>

* uncomment type MaxIterations

* reactivate append storage feature

Co-authored-by: Benjamin Kampmann <ben@gnunicorn.org>
Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>

polkadot/service/Cargo.toml

@@ -25,11 +25,11 @@ sp-api = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sp-runtime = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sp-blockchain = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sp-core = { git = "https://github.com/paritytech/substrate", branch = "master" }
-sc-client = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sc-client-api = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sc-client-db = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sc-chain-spec = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sc-executor = { git = "https://github.com/paritytech/substrate", branch = "master" }
+sc-consensus = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sc-network = { git = "https://github.com/paritytech/substrate", branch = "master" }
 consensus_common = { package = "sp-consensus", git = "https://github.com/paritytech/substrate", branch = "master" }
 grandpa = { package = "sc-finality-grandpa", git = "https://github.com/paritytech/substrate", branch = "master" }
@@ -37,6 +37,7 @@ grandpa_primitives = { package = "sp-finality-grandpa", git = "https://github.co
 inherents = { package = "sp-inherents", git = "https://github.com/paritytech/substrate", branch = "master" }
 service = { package = "sc-service", git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 telemetry = { package = "sc-telemetry", git = "https://github.com/paritytech/substrate", branch = "master" }
+sc-block-builder = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sc-transaction-pool = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sp-transaction-pool = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sc-keystore = { git = "https://github.com/paritytech/substrate", branch = "master" }

polkadot/service/src/chain_spec.rs

@@ -48,9 +48,9 @@ const DEFAULT_PROTOCOL_ID: &str = "dot";
 #[serde(rename_all = "camelCase")]
 pub struct Extensions {
 	/// Block numbers with known hashes.
-	pub fork_blocks: sc_client::ForkBlocks<polkadot_primitives::Block>,
+	pub fork_blocks: sc_client_api::ForkBlocks<polkadot_primitives::Block>,
 	/// Known bad block hashes.
-	pub bad_blocks: sc_client::BadBlocks<polkadot_primitives::Block>,
+	pub bad_blocks: sc_client_api::BadBlocks<polkadot_primitives::Block>,
 }
 
 /// The `ChainSpec parametrised for polkadot runtime`.

polkadot/service/src/lib.rs

@@ -19,7 +19,6 @@
 pub mod chain_spec;
 mod grandpa_support;
 
-use sc_client::LongestChain;
 use std::sync::Arc;
 use std::time::Duration;
 use polkadot_primitives::{parachain, Hash, BlockId, AccountId, Nonce, Balance};
@@ -27,21 +26,20 @@ use polkadot_primitives::{parachain, Hash, BlockId, AccountId, Nonce, Balance};
 use polkadot_network::{legacy::gossip::Known, protocol as network_protocol};
 use service::{error::Error as ServiceError, ServiceBuilder};
 use grandpa::{self, FinalityProofProvider as GrandpaFinalityProofProvider};
-use inherents::InherentDataProviders;
 use sc_executor::native_executor_instance;
 use log::info;
 pub use service::{
 	AbstractService, Role, PruningMode, TransactionPoolOptions, Error, RuntimeGenesis,
 	TFullClient, TLightClient, TFullBackend, TLightBackend, TFullCallExecutor, TLightCallExecutor,
-	Configuration, ChainSpec, ServiceBuilderCommand,
+	Configuration, ChainSpec, ServiceBuilderCommand, ClientProvider,
 };
 pub use service::config::{DatabaseConfig, PrometheusConfig};
 pub use sc_executor::NativeExecutionDispatch;
-pub use sc_client::{ExecutionStrategy, CallExecutor, Client};
-pub use sc_client_api::backend::Backend;
+pub use sc_client_api::{Backend, ExecutionStrategy, CallExecutor};
+pub use sc_consensus::LongestChain;
 pub use sp_api::{Core as CoreApi, ConstructRuntimeApi, ProvideRuntimeApi, StateBackend};
 pub use sp_runtime::traits::{HashFor, NumberFor};
-pub use consensus_common::SelectChain;
+pub use consensus_common::{SelectChain, BlockImport, block_validation::Chain};
 pub use polkadot_primitives::parachain::{CollatorId, ParachainHost};
 pub use polkadot_primitives::Block;
 pub use sp_runtime::traits::{Block as BlockT, self as runtime_traits, BlakeTwo256};
@@ -76,7 +74,7 @@ native_executor_instance!(
 );
 
 /// A set of APIs that polkadot-like runtimes must implement.
-pub trait RuntimeApiCollection<Extrinsic: codec::Codec + Send + Sync + 'static> :
+pub trait RuntimeApiCollection<Extrinsic: codec::Codec + Send + Sync + 'static>:
 	sp_transaction_pool::runtime_api::TaggedTransactionQueue<Block>
 	+ sp_api::ApiExt<Block, Error = sp_blockchain::Error>
 	+ babe_primitives::BabeApi<Block>
@@ -156,7 +154,7 @@ macro_rules! new_full_start {
 			Block, $runtime, $executor
 		>($config)?
 			.with_select_chain(|_, backend| {
-				Ok(sc_client::LongestChain::new(backend.clone()))
+				Ok(sc_consensus::LongestChain::new(backend.clone()))
 			})?
 			.with_transaction_pool(|config, client, _fetcher, prometheus_registry| {
 				let pool_api = sc_transaction_pool::FullChainApi::new(client.clone());
@@ -209,6 +207,352 @@ macro_rules! new_full_start {
 	}}
 }
 
+/// Builds a new service for a full client.
+#[macro_export]
+macro_rules! new_full {
+	(
+		$config:expr,
+		$collating_for:expr,
+		$max_block_data_size:expr,
+		$authority_discovery_enabled:expr,
+		$slot_duration:expr,
+		$grandpa_pause:expr,
+		$runtime:ty,
+		$dispatch:ty
+	) => {{
+		use sc_network::Event;
+		use sc_client_api::ExecutorProvider;
+		use futures::stream::StreamExt;
+
+		let is_collator = $collating_for.is_some();
+		let role = $config.role.clone();
+		let is_authority = role.is_authority() && !is_collator;
+		let force_authoring = $config.force_authoring;
+		let max_block_data_size = $max_block_data_size;
+		let db_path = match $config.database.path() {
+			Some(path) => std::path::PathBuf::from(path),
+			None => return Err("Starting a Polkadot service with a custom database isn't supported".to_string().into()),
+		};
+		let disable_grandpa = $config.disable_grandpa;
+		let name = $config.network.node_name.clone();
+		let authority_discovery_enabled = $authority_discovery_enabled;
+		let slot_duration = $slot_duration;
+
+		let (builder, mut import_setup, inherent_data_providers) = new_full_start!($config, $runtime, $dispatch);
+
+		let backend = builder.backend().clone();
+
+		let service = builder
+			.with_finality_proof_provider(|client, backend| {
+				let provider = client as Arc<dyn grandpa::StorageAndProofProvider<_, _>>;
+				Ok(Arc::new(GrandpaFinalityProofProvider::new(backend, provider)) as _)
+			})?
+			.build()?;
+
+		let (block_import, link_half, babe_link) = import_setup.take()
+			.expect("Link Half and Block Import are present for Full Services or setup failed before. qed");
+
+		let client = service.client();
+		let known_oracle = client.clone();
+
+		let mut handles = FullNodeHandles::default();
+		let select_chain = if let Some(select_chain) = service.select_chain() {
+			select_chain
+		} else {
+			info!("The node cannot start as an authority because it can't select chain.");
+			return Ok((service, client, handles));
+		};
+		let gossip_validator_select_chain = select_chain.clone();
+
+		let is_known = move |block_hash: &Hash| {
+			use consensus_common::BlockStatus;
+
+			match known_oracle.block_status(&BlockId::hash(*block_hash)) {
+				Err(_) | Ok(BlockStatus::Unknown) | Ok(BlockStatus::Queued) => None,
+				Ok(BlockStatus::KnownBad) => Some(Known::Bad),
+				Ok(BlockStatus::InChainWithState) | Ok(BlockStatus::InChainPruned) => {
+					match gossip_validator_select_chain.leaves() {
+						Err(_) => None,
+						Ok(leaves) => if leaves.contains(block_hash) {
+							Some(Known::Leaf)
+						} else {
+							Some(Known::Old)
+						},
+					}
+				}
+			}
+		};
+
+		let polkadot_network_service = network_protocol::start(
+			service.network(),
+			network_protocol::Config {
+				collating_for: $collating_for,
+			},
+			(is_known, client.clone()),
+			client.clone(),
+			service.spawn_task_handle(),
+		).map_err(|e| format!("Could not spawn network worker: {:?}", e))?;
+
+		let authority_handles = if is_collator || role.is_authority() {
+			let availability_store = {
+				use std::path::PathBuf;
+
+				let mut path = PathBuf::from(db_path);
+				path.push("availability");
+
+				#[cfg(not(target_os = "unknown"))]
+				{
+					av_store::Store::new(
+						::av_store::Config {
+							cache_size: None,
+							path,
+						},
+						polkadot_network_service.clone(),
+					)?
+				}
+
+				#[cfg(target_os = "unknown")]
+				av_store::Store::new_in_memory(gossip)
+			};
+
+			polkadot_network_service.register_availability_store(availability_store.clone());
+
+			let (validation_service_handle, validation_service) = consensus::ServiceBuilder {
+				client: client.clone(),
+				network: polkadot_network_service.clone(),
+				collators: polkadot_network_service.clone(),
+				spawner: service.spawn_task_handle(),
+				availability_store: availability_store.clone(),
+				select_chain: select_chain.clone(),
+				keystore: service.keystore(),
+				max_block_data_size,
+			}.build();
+
+			service.spawn_essential_task("validation-service", Box::pin(validation_service));
+
+			handles.validation_service_handle = Some(validation_service_handle.clone());
+
+			Some((validation_service_handle, availability_store))
+		} else {
+			None
+		};
+
+		if role.is_authority() {
+			let (validation_service_handle, availability_store) = authority_handles
+				.clone()
+				.expect("Authority handles are set for authority nodes; qed");
+
+			let proposer = consensus::ProposerFactory::new(
+				client.clone(),
+				service.transaction_pool(),
+				validation_service_handle,
+				slot_duration,
+				backend,
+			);
+
+			let select_chain = service.select_chain().ok_or(ServiceError::SelectChainRequired)?;
+			let can_author_with =
+				consensus_common::CanAuthorWithNativeVersion::new(client.executor().clone());
+
+			let block_import = availability_store.block_import(
+				block_import,
+				client.clone(),
+				service.spawn_task_handle(),
+				service.keystore(),
+			)?;
+
+			let babe_config = babe::BabeParams {
+				keystore: service.keystore(),
+				client: client.clone(),
+				select_chain,
+				block_import,
+				env: proposer,
+				sync_oracle: service.network(),
+				inherent_data_providers: inherent_data_providers.clone(),
+				force_authoring,
+				babe_link,
+				can_author_with,
+			};
+
+			let babe = babe::start_babe(babe_config)?;
+			service.spawn_essential_task("babe", babe);
+		}
+
+		if matches!(role, Role::Authority{..} | Role::Sentry{..}) {
+			if authority_discovery_enabled {
+				let (sentries, authority_discovery_role) = match role {
+					Role::Authority { ref sentry_nodes } => (
+						sentry_nodes.clone(),
+						authority_discovery::Role::Authority (
+							service.keystore(),
+						),
+					),
+					Role::Sentry {..} => (
+						vec![],
+						authority_discovery::Role::Sentry,
+					),
+					_ => unreachable!("Due to outer matches! constraint; qed."),
+				};
+
+				let network = service.network();
+				let network_event_stream = network.event_stream("authority-discovery");
+				let dht_event_stream = network_event_stream.filter_map(|e| async move { match e {
+					Event::Dht(e) => Some(e),
+					_ => None,
+				}}).boxed();
+				let authority_discovery = authority_discovery::AuthorityDiscovery::new(
+					service.client(),
+					network,
+					sentries,
+					dht_event_stream,
+					authority_discovery_role,
+					service.prometheus_registry(),
+				);
+
+				service.spawn_task("authority-discovery", authority_discovery);
+			}
+		}
+
+		// if the node isn't actively participating in consensus then it doesn't
+		// need a keystore, regardless of which protocol we use below.
+		let keystore = if is_authority {
+			Some(service.keystore())
+		} else {
+			None
+		};
+
+		let config = grandpa::Config {
+			// FIXME substrate#1578 make this available through chainspec
+			gossip_duration: Duration::from_millis(1000),
+			justification_period: 512,
+			name: Some(name),
+			observer_enabled: false,
+			keystore,
+			is_authority: role.is_network_authority(),
+		};
+
+		let enable_grandpa = !disable_grandpa;
+		if enable_grandpa {
+			// start the full GRANDPA voter
+			// NOTE: unlike in substrate we are currently running the full
+			// GRANDPA voter protocol for all full nodes (regardless of whether
+			// they're validators or not). at this point the full voter should
+			// provide better guarantees of block and vote data availability than
+			// the observer.
+
+			// add a custom voting rule to temporarily stop voting for new blocks
+			// after the given pause block is finalized and restarting after the
+			// given delay.
+			let voting_rule = match $grandpa_pause {
+				Some((block, delay)) => {
+					info!("GRANDPA scheduled voting pause set for block #{} with a duration of {} blocks.",
+						block,
+						delay,
+					);
+
+					grandpa::VotingRulesBuilder::default()
+						.add(grandpa_support::PauseAfterBlockFor(block, delay))
+						.build()
+				},
+				None =>
+					grandpa::VotingRulesBuilder::default()
+						.build(),
+			};
+
+			let grandpa_config = grandpa::GrandpaParams {
+				config,
+				link: link_half,
+				network: service.network(),
+				inherent_data_providers: inherent_data_providers.clone(),
+				telemetry_on_connect: Some(service.telemetry_on_connect_stream()),
+				voting_rule,
+				prometheus_registry: service.prometheus_registry(),
+			};
+
+			service.spawn_essential_task(
+				"grandpa-voter",
+				grandpa::run_grandpa_voter(grandpa_config)?
+			);
+		} else {
+			grandpa::setup_disabled_grandpa(
+				client.clone(),
+				&inherent_data_providers,
+				service.network(),
+			)?;
+		}
+
+		handles.polkadot_network = Some(polkadot_network_service);
+		(service, client, handles)
+	}}
+}
+
+/// Builds a new service for a light client.
+#[macro_export]
+macro_rules! new_light {
+	($config:expr, $runtime:ty, $dispatch:ty) => {{
+		crate::set_prometheus_registry(&mut $config)?;
+		let inherent_data_providers = inherents::InherentDataProviders::new();
+
+		ServiceBuilder::new_light::<Block, $runtime, $dispatch>($config)?
+			.with_select_chain(|_, backend| {
+				Ok(sc_consensus::LongestChain::new(backend.clone()))
+			})?
+			.with_transaction_pool(|config, client, fetcher, prometheus_registry| {
+				let fetcher = fetcher
+					.ok_or_else(|| "Trying to start light transaction pool without active fetcher")?;
+				let pool_api = sc_transaction_pool::LightChainApi::new(client.clone(), fetcher.clone());
+				let pool = sc_transaction_pool::BasicPool::with_revalidation_type(
+					config, Arc::new(pool_api), prometheus_registry, sc_transaction_pool::RevalidationType::Light,
+				);
+				Ok(pool)
+			})?
+			.with_import_queue_and_fprb(|_config, client, backend, fetcher, _select_chain, _| {
+				let fetch_checker = fetcher
+					.map(|fetcher| fetcher.checker().clone())
+					.ok_or_else(|| "Trying to start light import queue without active fetch checker")?;
+				let grandpa_block_import = grandpa::light_block_import(
+					client.clone(), backend, &(client.clone() as Arc<_>), Arc::new(fetch_checker)
+				)?;
+
+				let finality_proof_import = grandpa_block_import.clone();
+				let finality_proof_request_builder =
+					finality_proof_import.create_finality_proof_request_builder();
+
+				let (babe_block_import, babe_link) = babe::block_import(
+					babe::Config::get_or_compute(&*client)?,
+					grandpa_block_import,
+					client.clone(),
+				)?;
+
+				// FIXME: pruning task isn't started since light client doesn't do `AuthoritySetup`.
+				let import_queue = babe::import_queue(
+					babe_link,
+					babe_block_import,
+					None,
+					Some(Box::new(finality_proof_import)),
+					client,
+					inherent_data_providers.clone(),
+				)?;
+
+				Ok((import_queue, finality_proof_request_builder))
+			})?
+			.with_finality_proof_provider(|client, backend| {
+				let provider = client as Arc<dyn grandpa::StorageAndProofProvider<_, _>>;
+				Ok(Arc::new(grandpa::FinalityProofProvider::new(backend, provider)) as _)
+			})?
+			.with_rpc_extensions(|builder|
+				-> Result<polkadot_rpc::RpcExtension, _> {
+				let fetcher = builder.fetcher()
+					.ok_or_else(|| "Trying to start node RPC without active fetcher")?;
+				let remote_blockchain = builder.remote_backend()
+					.ok_or_else(|| "Trying to start node RPC without active remote blockchain")?;
+
+				Ok(polkadot_rpc::create_light(builder.client().clone(), remote_blockchain, fetcher, builder.pool()))
+			})?
+			.build()
+	}}
+}
+
 /// Builds a new object suitable for chain operations.
 pub fn new_chain_ops<Runtime, Dispatch, Extrinsic>(mut config: Configuration)
 	-> Result<impl ServiceBuilderCommand<Block=Block>, ServiceError>
@@ -227,7 +571,7 @@ where
 /// Create a new Polkadot service for a full node.
 #[cfg(feature = "full-node")]
 pub fn polkadot_new_full(
-	config: Configuration,
+	mut config: Configuration,
 	collating_for: Option<(CollatorId, parachain::Id)>,
 	max_block_data_size: Option<u64>,
 	authority_discovery_enabled: bool,
@@ -235,61 +579,69 @@ pub fn polkadot_new_full(
 	grandpa_pause: Option<(u32, u32)>,
 )
 	-> Result<(
-		impl AbstractService<
-			Block = Block,
-			RuntimeApi = polkadot_runtime::RuntimeApi,
-			Backend = TFullBackend<Block>,
-			SelectChain = LongestChain<TFullBackend<Block>, Block>,
-			CallExecutor = TFullCallExecutor<Block, PolkadotExecutor>,
-		>,
+		impl AbstractService,
+		Arc<impl ClientProvider<
+			Block,
+			TFullBackend<Block>,
+			TFullCallExecutor<Block, PolkadotExecutor>,
+			polkadot_runtime::RuntimeApi
+		>>,
 		FullNodeHandles,
 	), ServiceError>
 {
-	new_full(
+	let (service, client, handles) = new_full!(
 		config,
 		collating_for,
 		max_block_data_size,
 		authority_discovery_enabled,
 		slot_duration,
 		grandpa_pause,
-	)
+		polkadot_runtime::RuntimeApi,
+		PolkadotExecutor
+	);
+
+	Ok((service, client, handles))
 }
 
 /// Create a new Kusama service for a full node.
 #[cfg(feature = "full-node")]
 pub fn kusama_new_full(
-	config: Configuration,
+	mut config: Configuration,
 	collating_for: Option<(CollatorId, parachain::Id)>,
 	max_block_data_size: Option<u64>,
 	authority_discovery_enabled: bool,
 	slot_duration: u64,
 	grandpa_pause: Option<(u32, u32)>,
-)
-	-> Result<(
-		impl AbstractService<
-			Block = Block,
-			RuntimeApi = kusama_runtime::RuntimeApi,
-			Backend = TFullBackend<Block>,
-			SelectChain = LongestChain<TFullBackend<Block>, Block>,
-			CallExecutor = TFullCallExecutor<Block, KusamaExecutor>,
+) -> Result<(
+		impl AbstractService,
+		Arc<impl ClientProvider<
+			Block,
+			TFullBackend<Block>,
+			TFullCallExecutor<Block, KusamaExecutor>,
+			kusama_runtime::RuntimeApi
+			>
 		>,
-		FullNodeHandles,
+		FullNodeHandles
 	), ServiceError>
 {
-	new_full(
+	let (service, client, handles) = new_full!(
 		config,
 		collating_for,
 		max_block_data_size,
 		authority_discovery_enabled,
 		slot_duration,
 		grandpa_pause,
-	)
+		kusama_runtime::RuntimeApi,
+		KusamaExecutor
+	);
+
+	Ok((service, client, handles))
 }
 
 /// Create a new Kusama service for a full node.
 #[cfg(feature = "full-node")]
 pub fn westend_new_full(
-	config: Configuration,
+	mut config: Configuration,
 	collating_for: Option<(CollatorId, parachain::Id)>,
 	max_block_data_size: Option<u64>,
 	authority_discovery_enabled: bool,
@@ -297,24 +649,28 @@ pub fn westend_new_full(
 	grandpa_pause: Option<(u32, u32)>,
 )
 	-> Result<(
-		impl AbstractService<
-			Block = Block,
-			RuntimeApi = westend_runtime::RuntimeApi,
-			Backend = TFullBackend<Block>,
-			SelectChain = LongestChain<TFullBackend<Block>, Block>,
-			CallExecutor = TFullCallExecutor<Block, KusamaExecutor>,
-		>,
+		impl AbstractService,
+		Arc<impl ClientProvider<
+			Block,
+			TFullBackend<Block>,
+			TFullCallExecutor<Block, KusamaExecutor>,
+			westend_runtime::RuntimeApi
+		>>,
 		FullNodeHandles,
 	), ServiceError>
 {
-	new_full(
+	let (service, client, handles) = new_full!(
 		config,
 		collating_for,
 		max_block_data_size,
 		authority_discovery_enabled,
 		slot_duration,
 		grandpa_pause,
-	)
+		westend_runtime::RuntimeApi,
+		KusamaExecutor
+	);
+
+	Ok((service, client, handles))
 }
 
 /// Handles to other sub-services that full nodes instantiate, which consumers
@@ -328,305 +684,9 @@ pub struct FullNodeHandles {
 	pub validation_service_handle: Option<consensus::ServiceHandle>,
 }
 
-/// Builds a new service for a full client.
-#[cfg(feature = "full-node")]
-pub fn new_full<Runtime, Dispatch, Extrinsic>(
-	mut config: Configuration,
-	collating_for: Option<(CollatorId, parachain::Id)>,
-	max_block_data_size: Option<u64>,
-	authority_discovery_enabled: bool,
-	slot_duration: u64,
-	grandpa_pause: Option<(u32, u32)>,
-)
-	-> Result<(
-		impl AbstractService<
-			Block = Block,
-			RuntimeApi = Runtime,
-			Backend = TFullBackend<Block>,
-			SelectChain = LongestChain<TFullBackend<Block>, Block>,
-			CallExecutor = TFullCallExecutor<Block, Dispatch>,
-		>,
-		FullNodeHandles,
-	), ServiceError>
-	where
-		Runtime: ConstructRuntimeApi<Block, service::TFullClient<Block, Runtime, Dispatch>> + Send + Sync + 'static,
-		Runtime::RuntimeApi:
-			RuntimeApiCollection<Extrinsic, StateBackend = sc_client_api::StateBackendFor<TFullBackend<Block>, Block>>,
-		Dispatch: NativeExecutionDispatch + 'static,
-		Extrinsic: RuntimeExtrinsic,
-		// Rust bug: https://github.com/rust-lang/rust/issues/24159
-		<Runtime::RuntimeApi as sp_api::ApiExt<Block>>::StateBackend: sp_api::StateBackend<BlakeTwo256>,
-{
-	use sc_network::Event;
-	use sc_client_api::ExecutorProvider;
-	use futures::stream::StreamExt;
-
-	let is_collator = collating_for.is_some();
-	let role = config.role.clone();
-	let is_authority = role.is_authority() && !is_collator;
-	let force_authoring = config.force_authoring;
-	let max_block_data_size = max_block_data_size;
-	let db_path = match config.database.path() {
-		Some(path) => std::path::PathBuf::from(path),
-		None => return Err("Starting a Polkadot service with a custom database isn't supported".to_string().into()),
-	};
-	let disable_grandpa = config.disable_grandpa;
-	let name = config.network.node_name.clone();
-	let authority_discovery_enabled = authority_discovery_enabled;
-	let slot_duration = slot_duration;
-
-	let (builder, mut import_setup, inherent_data_providers) = new_full_start!(config, Runtime, Dispatch);
-
-	let backend = builder.backend().clone();
-
-	let service = builder
-		.with_finality_proof_provider(|client, backend| {
-			let provider = client as Arc<dyn grandpa::StorageAndProofProvider<_, _>>;
-			Ok(Arc::new(GrandpaFinalityProofProvider::new(backend, provider)) as _)
-		})?
-		.build()?;
-
-	let (block_import, link_half, babe_link) = import_setup.take()
-		.expect("Link Half and Block Import are present for Full Services or setup failed before. qed");
-
-	let client = service.client();
-	let known_oracle = client.clone();
-
-	let mut handles = FullNodeHandles::default();
-	let select_chain = if let Some(select_chain) = service.select_chain() {
-		select_chain
-	} else {
-		info!("The node cannot start as an authority because it can't select chain.");
-		return Ok((service, handles));
-	};
-	let gossip_validator_select_chain = select_chain.clone();
-
-	let is_known = move |block_hash: &Hash| {
-		use consensus_common::BlockStatus;
-
-		match known_oracle.block_status(&BlockId::hash(*block_hash)) {
-			Err(_) | Ok(BlockStatus::Unknown) | Ok(BlockStatus::Queued) => None,
-			Ok(BlockStatus::KnownBad) => Some(Known::Bad),
-			Ok(BlockStatus::InChainWithState) | Ok(BlockStatus::InChainPruned) => {
-				match gossip_validator_select_chain.leaves() {
-					Err(_) => None,
-					Ok(leaves) => if leaves.contains(block_hash) {
-						Some(Known::Leaf)
-					} else {
-						Some(Known::Old)
-					},
-				}
-			}
-		}
-	};
-
-	let polkadot_network_service = network_protocol::start(
-		service.network(),
-		network_protocol::Config {
-			collating_for,
-		},
-		(is_known, client.clone()),
-		client.clone(),
-		service.spawn_task_handle(),
-	).map_err(|e| format!("Could not spawn network worker: {:?}", e))?;
-
-	let authority_handles = if is_collator || role.is_authority() {
-		let availability_store = {
-			use std::path::PathBuf;
-
-			let mut path = PathBuf::from(db_path);
-			path.push("availability");
-
-			#[cfg(not(target_os = "unknown"))]
-			{
-				av_store::Store::new(
-					::av_store::Config {
-						cache_size: None,
-						path,
-					},
-					polkadot_network_service.clone(),
-				)?
-			}
-
-			#[cfg(target_os = "unknown")]
-			av_store::Store::new_in_memory(gossip)
-		};
-
-		polkadot_network_service.register_availability_store(availability_store.clone());
-
-		let (validation_service_handle, validation_service) = consensus::ServiceBuilder {
-			client: client.clone(),
-			network: polkadot_network_service.clone(),
-			collators: polkadot_network_service.clone(),
-			spawner: service.spawn_task_handle(),
-			availability_store: availability_store.clone(),
-			select_chain: select_chain.clone(),
-			keystore: service.keystore(),
-			max_block_data_size,
-		}.build();
-
-		service.spawn_essential_task("validation-service", Box::pin(validation_service));
-
-		handles.validation_service_handle = Some(validation_service_handle.clone());
-
-		Some((validation_service_handle, availability_store))
-	} else {
-		None
-	};
-
-	if role.is_authority() {
-		let (validation_service_handle, availability_store) = authority_handles
-			.clone()
-			.expect("Authority handles are set for authority nodes; qed");
-
-		let proposer = consensus::ProposerFactory::new(
-			client.clone(),
-			service.transaction_pool(),
-			validation_service_handle,
-			slot_duration,
-			backend,
-		);
-
-		let select_chain = service.select_chain().ok_or(ServiceError::SelectChainRequired)?;
-		let can_author_with =
-			consensus_common::CanAuthorWithNativeVersion::new(client.executor().clone());
-
-		let block_import = availability_store.block_import(
-			block_import,
-			client.clone(),
-			service.spawn_task_handle(),
-			service.keystore(),
-		)?;
-
-		let babe_config = babe::BabeParams {
-			keystore: service.keystore(),
-			client,
-			select_chain,
-			block_import,
-			env: proposer,
-			sync_oracle: service.network(),
-			inherent_data_providers: inherent_data_providers.clone(),
-			force_authoring,
-			babe_link,
-			can_author_with,
-		};
-
-		let babe = babe::start_babe(babe_config)?;
-		service.spawn_essential_task("babe", babe);
-	}
-
-	if matches!(role, Role::Authority{..} | Role::Sentry{..}) {
-		if authority_discovery_enabled {
-			let (sentries, authority_discovery_role) = match role {
-				Role::Authority { ref sentry_nodes } => (
-					sentry_nodes.clone(),
-					authority_discovery::Role::Authority (
-						service.keystore(),
-					),
-				),
-				Role::Sentry {..} => (
-					vec![],
-					authority_discovery::Role::Sentry,
-				),
-				_ => unreachable!("Due to outer matches! constraint; qed."),
-			};
-
-			let network = service.network();
-			let network_event_stream = network.event_stream("authority-discovery");
-			let dht_event_stream = network_event_stream.filter_map(|e| async move { match e {
-				Event::Dht(e) => Some(e),
-				_ => None,
-			}}).boxed();
-			let authority_discovery = authority_discovery::AuthorityDiscovery::new(
-				service.client(),
-				network,
-				sentries,
-				dht_event_stream,
-				authority_discovery_role,
-				service.prometheus_registry(),
-			);
-
-			service.spawn_task("authority-discovery", authority_discovery);
-		}
-	}
-
-	// if the node isn't actively participating in consensus then it doesn't
-	// need a keystore, regardless of which protocol we use below.
-	let keystore = if is_authority {
-		Some(service.keystore())
-	} else {
-		None
-	};
-
-	let config = grandpa::Config {
-		// FIXME substrate#1578 make this available through chainspec
-		gossip_duration: Duration::from_millis(1000),
-		justification_period: 512,
-		name: Some(name),
-		observer_enabled: false,
-		keystore,
-		is_authority: role.is_network_authority(),
-	};
-
-	let enable_grandpa = !disable_grandpa;
-	if enable_grandpa {
-		// start the full GRANDPA voter
-		// NOTE: unlike in substrate we are currently running the full
-		// GRANDPA voter protocol for all full nodes (regardless of whether
-		// they're validators or not). at this point the full voter should
-		// provide better guarantees of block and vote data availability than
-		// the observer.
-
-		// add a custom voting rule to temporarily stop voting for new blocks
-		// after the given pause block is finalized and restarting after the
-		// given delay.
-		let voting_rule = match grandpa_pause {
-			Some((block, delay)) => {
-				info!("GRANDPA scheduled voting pause set for block #{} with a duration of {} blocks.",
-					block,
-					delay,
-				);
-
-				grandpa::VotingRulesBuilder::default()
-					.add(grandpa_support::PauseAfterBlockFor(block, delay))
-					.build()
-			},
-			None =>
-				grandpa::VotingRulesBuilder::default()
-					.build(),
-		};
-
-		let grandpa_config = grandpa::GrandpaParams {
-			config,
-			link: link_half,
-			network: service.network(),
-			inherent_data_providers: inherent_data_providers.clone(),
-			telemetry_on_connect: Some(service.telemetry_on_connect_stream()),
-			voting_rule,
-			prometheus_registry: service.prometheus_registry(),
-		};
-
-		service.spawn_essential_task(
-			"grandpa-voter",
-			grandpa::run_grandpa_voter(grandpa_config)?
-		);
-	} else {
-		grandpa::setup_disabled_grandpa(
-			service.client(),
-			&inherent_data_providers,
-			service.network(),
-		)?;
-	}
-
-	handles.polkadot_network = Some(polkadot_network_service);
-	Ok((service, handles))
-}
-
 /// Create a new Polkadot service for a light client.
-pub fn polkadot_new_light(
-	config: Configuration,
-)
-	-> Result<impl AbstractService<
+pub fn polkadot_new_light(mut config: Configuration) -> Result<
+	impl AbstractService<
 		Block = Block,
 		RuntimeApi = polkadot_runtime::RuntimeApi,
 		Backend = TLightBackend<Block>,
@@ -634,14 +694,12 @@ pub fn polkadot_new_light(
 		CallExecutor = TLightCallExecutor<Block, PolkadotExecutor>,
 	>, ServiceError>
 {
-	new_light(config)
+	new_light!(config, polkadot_runtime::RuntimeApi, PolkadotExecutor)
 }
 
 /// Create a new Kusama service for a light client.
-pub fn kusama_new_light(
-	config: Configuration,
-)
-	-> Result<impl AbstractService<
+pub fn kusama_new_light(mut config: Configuration) -> Result<
+	impl AbstractService<
 		Block = Block,
 		RuntimeApi = kusama_runtime::RuntimeApi,
 		Backend = TLightBackend<Block>,
@@ -649,125 +707,19 @@ pub fn kusama_new_light(
 		CallExecutor = TLightCallExecutor<Block, KusamaExecutor>,
 	>, ServiceError>
 {
-	new_light(config)
+	new_light!(config, kusama_runtime::RuntimeApi, KusamaExecutor)
 }
 
 /// Create a new Westend service for a light client.
-pub fn westend_new_light(
-	config: Configuration,
-)
-	-> Result<impl AbstractService<
+pub fn westend_new_light(mut config: Configuration, ) -> Result<
+	impl AbstractService<
 		Block = Block,
 		RuntimeApi = westend_runtime::RuntimeApi,
 		Backend = TLightBackend<Block>,
 		SelectChain = LongestChain<TLightBackend<Block>, Block>,
-		CallExecutor = TLightCallExecutor<Block, KusamaExecutor>,
-	>, ServiceError>
+		CallExecutor = TLightCallExecutor<Block, KusamaExecutor>
+	>,
+	ServiceError>
 {
-	new_light(config)
-}
-
-// We can't use service::TLightClient due to
-// Rust bug: https://github.com/rust-lang/rust/issues/43580
-type TLocalLightClient<Runtime, Dispatch> =  Client<
-	sc_client::light::backend::Backend<sc_client_db::light::LightStorage<Block>, BlakeTwo256>,
-	sc_client::light::call_executor::GenesisCallExecutor<
-		sc_client::light::backend::Backend<sc_client_db::light::LightStorage<Block>, BlakeTwo256>,
-		sc_client::LocalCallExecutor<
-			sc_client::light::backend::Backend<
-				sc_client_db::light::LightStorage<Block>,
-				BlakeTwo256
-			>,
-			sc_executor::NativeExecutor<Dispatch>
-		>
-	>,
-	Block,
-	Runtime
->;
-
-/// Builds a new service for a light client.
-pub fn new_light<Runtime, Dispatch, Extrinsic>(
-	mut config: Configuration,
-)
-	-> Result<impl AbstractService<
-		Block = Block,
-		RuntimeApi = Runtime,
-		Backend = TLightBackend<Block>,
-		SelectChain = LongestChain<TLightBackend<Block>, Block>,
-		CallExecutor = TLightCallExecutor<Block, Dispatch>,
-	>, ServiceError>
-where
-	Runtime: Send + Sync + 'static,
-	Runtime::RuntimeApi: RuntimeApiCollection<
-		Extrinsic,
-		StateBackend = sc_client_api::StateBackendFor<TLightBackend<Block>, Block>
-	>,
-	Dispatch: NativeExecutionDispatch + 'static,
-	Extrinsic: RuntimeExtrinsic,
-	Runtime: sp_api::ConstructRuntimeApi<
-		Block,
-		TLocalLightClient<Runtime, Dispatch>,
-	>,
-{
-	set_prometheus_registry(&mut config)?;
-
-	let inherent_data_providers = InherentDataProviders::new();
-
-	ServiceBuilder::new_light::<Block, Runtime, Dispatch>(config)?
-		.with_select_chain(|_, backend| {
-			Ok(LongestChain::new(backend.clone()))
-		})?
-		.with_transaction_pool(|config, client, fetcher, prometheus_registry| {
-			let fetcher = fetcher
-				.ok_or_else(|| "Trying to start light transaction pool without active fetcher")?;
-			let pool_api = sc_transaction_pool::LightChainApi::new(client.clone(), fetcher.clone());
-			let pool = sc_transaction_pool::BasicPool::with_revalidation_type(
-				config, Arc::new(pool_api), prometheus_registry, sc_transaction_pool::RevalidationType::Light,
-			);
-			Ok(pool)
-		})?
-		.with_import_queue_and_fprb(|_config, client, backend, fetcher, _select_chain, _| {
-			let fetch_checker = fetcher
-				.map(|fetcher| fetcher.checker().clone())
-				.ok_or_else(|| "Trying to start light import queue without active fetch checker")?;
-			let grandpa_block_import = grandpa::light_block_import(
-				client.clone(), backend, &(client.clone() as Arc<_>), Arc::new(fetch_checker)
-			)?;
-
-			let finality_proof_import = grandpa_block_import.clone();
-			let finality_proof_request_builder =
-				finality_proof_import.create_finality_proof_request_builder();
-
-			let (babe_block_import, babe_link) = babe::block_import(
-				babe::Config::get_or_compute(&*client)?,
-				grandpa_block_import,
-				client.clone(),
-			)?;
-
-			// FIXME: pruning task isn't started since light client doesn't do `AuthoritySetup`.
-			let import_queue = babe::import_queue(
-				babe_link,
-				babe_block_import,
-				None,
-				Some(Box::new(finality_proof_import)),
-				client,
-				inherent_data_providers.clone(),
-			)?;
-
-			Ok((import_queue, finality_proof_request_builder))
-		})?
-		.with_finality_proof_provider(|client, backend| {
-			let provider = client as Arc<dyn grandpa::StorageAndProofProvider<_, _>>;
-			Ok(Arc::new(GrandpaFinalityProofProvider::new(backend, provider)) as _)
-		})?
-		.with_rpc_extensions(|builder|
-			-> Result<polkadot_rpc::RpcExtension, _> {
-			let fetcher = builder.fetcher()
-				.ok_or_else(|| "Trying to start node RPC without active fetcher")?;
-			let remote_blockchain = builder.remote_backend()
-				.ok_or_else(|| "Trying to start node RPC without active remote blockchain")?;
-
-			Ok(polkadot_rpc::create_light(builder.client().clone(), remote_blockchain, fetcher, builder.pool()))
-		})?
-		.build()
+	new_light!(config, westend_runtime::RuntimeApi, KusamaExecutor)
 }