Allow for customisation of chain selection systems (#2240)

* move SelectChain trait out of client * Extend SelectChain, move longest chain implementation into it * Bring SelectChain into service * implement LongestChain SelectChain * implement longest chain for node * update Cargo.lock's * in between erroring tests * deprecate ::backend and ::import_lock * Remove unneded space Co-Authored-By: gnunicorn <ben.kampmann@googlemail.com> * Remove unneded space Co-Authored-By: gnunicorn <ben.kampmann@googlemail.com> * Fixes test compilation * remove todo * re-enable client test * add doc * fixing tests * Clarify SelectChain Interface, intended implementation and usage * minor components cleanups * minor cleanups * Update lock files * Implement cleaner interface for SelectChain * addressing comments * Updating tests * bump node runtime impl version * address grumbles
2026-05-30 08:11:03 +00:00 · 2019-05-10 14:08:12 +02:00
parent 32fdeed21c
commit 18ca0170c3
22 changed files with 717 additions and 339 deletions
@@ -16,14 +16,14 @@

 //! Substrate service components.

-use std::{sync::Arc, net::SocketAddr, marker::PhantomData, ops::Deref, ops::DerefMut};
+use std::{sync::Arc, net::SocketAddr, ops::Deref, ops::DerefMut};
 use serde::{Serialize, de::DeserializeOwned};
 use tokio::runtime::TaskExecutor;
 use crate::chain_spec::ChainSpec;
 use client_db;
 use client::{self, Client, runtime_api};
 use crate::{error, Service, maybe_start_server};
-use consensus_common::import_queue::ImportQueue;
+use consensus_common::{import_queue::ImportQueue, SelectChain};
 use network::{self, OnDemand};
 use substrate_executor::{NativeExecutor, NativeExecutionDispatch};
 use transaction_pool::txpool::{self, Options as TransactionPoolOptions, Pool as TransactionPool};
@@ -304,9 +304,11 @@ pub trait ServiceFactory: 'static + Sized {
 	/// Extended light service type.
 	type LightService: ServiceTrait<LightComponents<Self>>;
 	/// ImportQueue for full client
-	type FullImportQueue: consensus_common::import_queue::ImportQueue<Self::Block> + 'static;
+	type FullImportQueue: ImportQueue<Self::Block> + 'static;
 	/// ImportQueue for light clients
-	type LightImportQueue: consensus_common::import_queue::ImportQueue<Self::Block> + 'static;
+	type LightImportQueue: ImportQueue<Self::Block> + 'static;
+	/// The Fork Choice Strategy for the chain
+	type SelectChain: SelectChain<Self::Block> + 'static;

 	//TODO: replace these with a constructor trait. that TransactionPool implements. (#1242)
 	/// Extrinsic pool constructor for the full client.
@@ -320,6 +322,12 @@ pub trait ServiceFactory: 'static + Sized {
 	fn build_network_protocol(config: &FactoryFullConfiguration<Self>)
 		-> Result<Self::NetworkProtocol, error::Error>;

+	/// Build the Fork Choice algorithm for full client
+	fn build_select_chain(
+		config: &mut FactoryFullConfiguration<Self>,
+		client: Arc<FullClient<Self>>, 
+	) -> Result<Self::SelectChain, error::Error>;
+
 	/// Build full service.
 	fn new_full(config: FactoryFullConfiguration<Self>, executor: TaskExecutor)
 		-> Result<Self::FullService, error::Error>;
@@ -330,7 +338,8 @@ pub trait ServiceFactory: 'static + Sized {
 	/// ImportQueue for a full client
 	fn build_full_import_queue(
 		config: &mut FactoryFullConfiguration<Self>,
-		_client: Arc<FullClient<Self>>
+		_client: Arc<FullClient<Self>>,
+		_select_chain: Self::SelectChain
 	) -> Result<Self::FullImportQueue, error::Error> {
 		if let Some(name) = config.chain_spec.consensus_engine() {
 			match name {
@@ -378,6 +387,8 @@ pub trait Components: Sized + 'static {
 	>;
 	/// Our Import Queue
 	type ImportQueue: ImportQueue<FactoryBlock<Self::Factory>> + 'static;
+	/// The Fork Choice Strategy for the chain
+	type SelectChain: SelectChain<FactoryBlock<Self::Factory>>;

 	/// Create client.
 	fn build_client(
@@ -398,13 +409,20 @@ pub trait Components: Sized + 'static {
 	/// instance of import queue for clients
 	fn build_import_queue(
 		config: &mut FactoryFullConfiguration<Self::Factory>,
-		client: Arc<ComponentClient<Self>>
+		client: Arc<ComponentClient<Self>>,
+		select_chain: Self::SelectChain,
 	) -> Result<Self::ImportQueue, error::Error>;
+
+	/// Build fork choice selector
+	fn build_select_chain(
+		config: &mut FactoryFullConfiguration<Self::Factory>,
+		client: Arc<ComponentClient<Self>>
+	) -> Result<Self::SelectChain, error::Error>;
+
 }

 /// A struct that implement `Components` for the full client.
 pub struct FullComponents<Factory: ServiceFactory> {
-	_factory: PhantomData<Factory>,
 	service: Service<FullComponents<Factory>>,
 }

@@ -416,7 +434,6 @@ impl<Factory: ServiceFactory> FullComponents<Factory> {
 	) -> Result<Self, error::Error> {
 		Ok(
 			Self {
-				_factory: Default::default(),
 				service: Service::new(config, task_executor)?,
 			}
 		)
@@ -445,6 +462,7 @@ impl<Factory: ServiceFactory> Components for FullComponents<Factory> {
 	type ImportQueue = Factory::FullImportQueue;
 	type RuntimeApi = Factory::RuntimeApi;
 	type RuntimeServices = Factory::FullService;
+	type SelectChain = Factory::SelectChain;

 	fn build_client(
 		config: &FactoryFullConfiguration<Factory>,
@@ -469,23 +487,32 @@ impl<Factory: ServiceFactory> Components for FullComponents<Factory> {
 		)?), None))
 	}

-	fn build_transaction_pool(config: TransactionPoolOptions, client: Arc<ComponentClient<Self>>)
-		-> Result<TransactionPool<Self::TransactionPoolApi>, error::Error>
-	{
+	fn build_transaction_pool(
+		config: TransactionPoolOptions, 
+		client: Arc<ComponentClient<Self>>
+	) -> Result<TransactionPool<Self::TransactionPoolApi>, error::Error> {
 		Factory::build_full_transaction_pool(config, client)
 	}

 	fn build_import_queue(
 		config: &mut FactoryFullConfiguration<Self::Factory>,
-		client: Arc<ComponentClient<Self>>
+		client: Arc<ComponentClient<Self>>,
+		select_chain: Self::SelectChain,
 	) -> Result<Self::ImportQueue, error::Error> {
-		Factory::build_full_import_queue(config, client)
+		Factory::build_full_import_queue(config, client, select_chain)
 	}
+
+	fn build_select_chain(
+		config: &mut FactoryFullConfiguration<Self::Factory>,
+		client: Arc<ComponentClient<Self>>
+	) -> Result<Self::SelectChain, error::Error> {
+		Self::Factory::build_select_chain(config, client)
+	}
+	
 }

 /// A struct that implement `Components` for the light client.
 pub struct LightComponents<Factory: ServiceFactory> {
-	_factory: PhantomData<Factory>,
 	service: Service<LightComponents<Factory>>,
 }

@@ -497,7 +524,6 @@ impl<Factory: ServiceFactory> LightComponents<Factory> {
 	) -> Result<Self, error::Error> {
 		Ok(
 			Self {
-				_factory: Default::default(),
 				service: Service::new(config, task_executor)?,
 			}
 		)
@@ -520,6 +546,7 @@ impl<Factory: ServiceFactory> Components for LightComponents<Factory> {
 	type ImportQueue = <Factory as ServiceFactory>::LightImportQueue;
 	type RuntimeApi = Factory::RuntimeApi;
 	type RuntimeServices = Factory::LightService;
+	type SelectChain = Factory::SelectChain;

 	fn build_client(
 		config: &FactoryFullConfiguration<Factory>,
@@ -554,16 +581,27 @@ impl<Factory: ServiceFactory> Components for LightComponents<Factory> {

 	fn build_import_queue(
 		config: &mut FactoryFullConfiguration<Self::Factory>,
-		client: Arc<ComponentClient<Self>>
+		client: Arc<ComponentClient<Self>>,
+		_select_chain: Self::SelectChain,
 	) -> Result<Self::ImportQueue, error::Error> {
 		Factory::build_light_import_queue(config, client)
 	}
+
+	/// Build fork choice selector
+	fn build_select_chain(
+		_config: &mut FactoryFullConfiguration<Self::Factory>,
+		_client: Arc<ComponentClient<Self>>
+	) -> Result<Self::SelectChain, error::Error> {
+		Err("Fork choice doesn't happen on light clients.".into())
+	}
+
 }

 #[cfg(test)]
 mod tests {
 	use super::*;
 	use consensus_common::BlockOrigin;
+	use client::LongestChain;
 	use substrate_test_client::{self, TestClient, AccountKeyring, runtime::Transfer};

 	#[test]
@@ -576,8 +614,11 @@ mod tests {
 			from: AccountKeyring::Alice.into(),
 			to: Default::default(),
 		}.into_signed_tx();
+		let best = LongestChain::new(client.backend().clone(), client.import_lock())
+			.best_chain().unwrap();
+
 		// store the transaction in the pool
-		pool.submit_one(&BlockId::hash(client.best_block_header().unwrap().hash()), transaction.clone()).unwrap();
+		pool.submit_one(&BlockId::hash(best.hash()), transaction.clone()).unwrap();

 		// import the block
 		let mut builder = client.new_block().unwrap();