Make chain && state RPCs async (#3480)

* chain+state RPCs are async now * wrapped too long lines * create full/light RPC impls from service * use ordering * post-merge fix
2026-07-10 08:47:32 +00:00 · 2019-09-01 03:20:10 +03:00
parent 816e132cd7
commit 607ee0a4e4
26 changed files with 1859 additions and 721 deletions
@@ -16,95 +16,181 @@

 //! Substrate blockchain API.

+mod chain_full;
+mod chain_light;
+
 #[cfg(test)]
 mod tests;

 use std::sync::Arc;
 use futures03::{future, StreamExt as _, TryStreamExt as _};
-
-use client::{self, Client, BlockchainEvents};
-use rpc::Result as RpcResult;
-use rpc::futures::{stream, Future, Sink, Stream};
-use api::Subscriptions;
-use jsonrpc_pubsub::{typed::Subscriber, SubscriptionId};
 use log::warn;
+use rpc::{
+	Result as RpcResult,
+	futures::{stream, Future, Sink, Stream},
+};
+
+use api::Subscriptions;
+use client::{
+	self, Client, BlockchainEvents,
+	light::{fetcher::Fetcher, blockchain::RemoteBlockchain},
+};
+use jsonrpc_pubsub::{typed::Subscriber, SubscriptionId};
 use primitives::{H256, Blake2Hasher};
-use sr_primitives::generic::{BlockId, SignedBlock};
-use sr_primitives::traits::{Block as BlockT, Header, NumberFor};
-use self::error::{Error, Result};
+use sr_primitives::{
+	generic::{BlockId, SignedBlock},
+	traits::{Block as BlockT, Header, NumberFor},
+};
+
+use self::error::{Result, Error, FutureResult};

 pub use api::chain::*;

-/// Chain API with subscriptions support.
-pub struct Chain<B, E, Block: BlockT, RA> {
-	/// Substrate client.
-	client: Arc<Client<B, E, Block, RA>>,
-	/// Current subscriptions.
-	subscriptions: Subscriptions,
-}
+/// Blockchain backend API
+trait ChainBackend<B, E, Block: BlockT, RA>: Send + Sync + 'static
+	where
+		Block: BlockT<Hash=H256> + 'static,
+		B: client::backend::Backend<Block, Blake2Hasher> + Send + Sync + 'static,
+		E: client::CallExecutor<Block, Blake2Hasher> + Send + Sync + 'static,
+{
+	/// Get client reference.
+	fn client(&self) -> &Arc<Client<B, E, Block, RA>>;

-impl<B, E, Block: BlockT, RA> Chain<B, E, Block, RA> {
-	/// Create new Chain API RPC handler.
-	pub fn new(client: Arc<Client<B, E, Block, RA>>, subscriptions: Subscriptions) -> Self {
-		Self {
-			client,
-			subscriptions,
+	/// Get subscriptions reference.
+	fn subscriptions(&self) -> &Subscriptions;
+
+	/// Tries to unwrap passed block hash, or uses best block hash otherwise.
+	fn unwrap_or_best(&self, hash: Option<Block::Hash>) -> Block::Hash {
+		match hash.into() {
+			None => self.client().info().chain.best_hash,
+			Some(hash) => hash,
 		}
 	}
-}

-impl<B, E, Block, RA> Chain<B, E, Block, RA> where
-	Block: BlockT<Hash=H256> + 'static,
-	B: client::backend::Backend<Block, Blake2Hasher> + Send + Sync + 'static,
-	E: client::CallExecutor<Block, Blake2Hasher> + Send + Sync + 'static,
-	RA: Send + Sync + 'static
-{
-	fn unwrap_or_best(&self, hash: Option<Block::Hash>) -> Result<Block::Hash> {
-		Ok(match hash.into() {
-			None => self.client.info().chain.best_hash,
-			Some(hash) => hash,
+	/// Get header of a relay chain block.
+	fn header(&self, hash: Option<Block::Hash>) -> FutureResult<Option<Block::Header>>;
+
+	/// Get header and body of a relay chain block.
+	fn block(&self, hash: Option<Block::Hash>) -> FutureResult<Option<SignedBlock<Block>>>;
+
+	/// Get hash of the n-th block in the canon chain.
+	///
+	/// By default returns latest block hash.
+	fn block_hash(
+		&self,
+		number: Option<number::NumberOrHex<NumberFor<Block>>>,
+	) -> Result<Option<Block::Hash>> {
+		Ok(match number {
+			None => Some(self.client().info().chain.best_hash),
+			Some(num_or_hex) => self.client()
+				.header(&BlockId::number(num_or_hex.to_number()?))
+				.map_err(client_err)?
+				.map(|h| h.hash()),
 		})
 	}

-	fn subscribe_headers<F, G, S, ERR>(
+	/// Get hash of the last finalized block in the canon chain.
+	fn finalized_head(&self) -> Result<Block::Hash> {
+		Ok(self.client().info().chain.finalized_hash)
+	}
+
+	/// New head subscription
+	fn subscribe_new_heads(
 		&self,
+		_metadata: crate::metadata::Metadata,
 		subscriber: Subscriber<Block::Header>,
-		best_block_hash: G,
-		stream: F,
-	) where
-		F: FnOnce() -> S,
-		G: FnOnce() -> Result<Option<Block::Hash>>,
-		ERR: ::std::fmt::Debug,
-		S: Stream<Item=Block::Header, Error=ERR> + Send + 'static,
-	{
-		self.subscriptions.add(subscriber, |sink| {
-			// send current head right at the start.
-			let header = best_block_hash()
-				.and_then(|hash| self.header(hash.into()))
-				.and_then(|header| {
-					header.ok_or_else(|| "Best header missing.".to_owned().into())
-				})
-				.map_err(Into::into);
+	) {
+		subscribe_headers(
+			self.client(),
+			self.subscriptions(),
+			subscriber,
+			|| self.client().info().chain.best_hash,
+			|| self.client().import_notification_stream()
+				.filter(|notification| future::ready(notification.is_new_best))
+				.map(|notification| Ok::<_, ()>(notification.header))
+				.compat(),
+		)
+	}

-			// send further subscriptions
-			let stream = stream()
-				.map(|res| Ok(res))
-				.map_err(|e| warn!("Block notification stream error: {:?}", e));
+	/// Unsubscribe from new head subscription.
+	fn unsubscribe_new_heads(
+		&self,
+		_metadata: Option<crate::metadata::Metadata>,
+		id: SubscriptionId,
+	) -> RpcResult<bool> {
+		Ok(self.subscriptions().cancel(id))
+	}

-			sink
-				.sink_map_err(|e| warn!("Error sending notifications: {:?}", e))
-				.send_all(
-					stream::iter_result(vec![Ok(header)])
-						.chain(stream)
-				)
-				// we ignore the resulting Stream (if the first stream is over we are unsubscribed)
-				.map(|_| ())
-		});
+	/// New head subscription
+	fn subscribe_finalized_heads(
+		&self,
+		_metadata: crate::metadata::Metadata,
+		subscriber: Subscriber<Block::Header>,
+	) {
+		subscribe_headers(
+			self.client(),
+			self.subscriptions(),
+			subscriber,
+			|| self.client().info().chain.finalized_hash,
+			|| self.client().finality_notification_stream()
+				.map(|notification| Ok::<_, ()>(notification.header))
+				.compat(),
+		)
+	}
+
+	/// Unsubscribe from new head subscription.
+	fn unsubscribe_finalized_heads(
+		&self,
+		_metadata: Option<crate::metadata::Metadata>,
+		id: SubscriptionId,
+	) -> RpcResult<bool> {
+		Ok(self.subscriptions().cancel(id))
 	}
 }

-fn client_error(err: client::error::Error) -> Error {
-	Error::Client(Box::new(err))
+/// Create new state API that works on full node.
+pub fn new_full<B, E, Block: BlockT, RA>(
+	client: Arc<Client<B, E, Block, RA>>,
+	subscriptions: Subscriptions,
+) -> Chain<B, E, Block, RA>
+	where
+		Block: BlockT<Hash=H256> + 'static,
+		B: client::backend::Backend<Block, Blake2Hasher> + Send + Sync + 'static,
+		E: client::CallExecutor<Block, Blake2Hasher> + Send + Sync + 'static + Clone,
+		RA: Send + Sync + 'static,
+{
+	Chain {
+		backend: Box::new(self::chain_full::FullChain::new(client, subscriptions)),
+	}
+}
+
+/// Create new state API that works on light node.
+pub fn new_light<B, E, Block: BlockT, RA, F: Fetcher<Block>>(
+	client: Arc<Client<B, E, Block, RA>>,
+	subscriptions: Subscriptions,
+	remote_blockchain: Arc<dyn RemoteBlockchain<Block>>,
+	fetcher: Arc<F>,
+) -> Chain<B, E, Block, RA>
+	where
+		Block: BlockT<Hash=H256> + 'static,
+		B: client::backend::Backend<Block, Blake2Hasher> + Send + Sync + 'static,
+		E: client::CallExecutor<Block, Blake2Hasher> + Send + Sync + 'static + Clone,
+		RA: Send + Sync + 'static,
+		F: Send + Sync + 'static,
+{
+	Chain {
+		backend: Box::new(self::chain_light::LightChain::new(
+			client,
+			subscriptions,
+			remote_blockchain,
+			fetcher,
+		)),
+	}
+}
+
+/// Chain API with subscriptions support.
+pub struct Chain<B, E, Block: BlockT, RA> {
+	backend: Box<dyn ChainBackend<B, E, Block, RA>>,
 }

 impl<B, E, Block, RA> ChainApi<NumberFor<Block>, Block::Hash, Block::Header, SignedBlock<Block>> for Chain<B, E, Block, RA> where
@@ -115,58 +201,81 @@ impl<B, E, Block, RA> ChainApi<NumberFor<Block>, Block::Hash, Block::Header, Sig
 {
 	type Metadata = crate::metadata::Metadata;

-	fn header(&self, hash: Option<Block::Hash>) -> Result<Option<Block::Header>> {
-		let hash = self.unwrap_or_best(hash)?;
-		Ok(self.client.header(&BlockId::Hash(hash)).map_err(client_error)?)
+	fn header(&self, hash: Option<Block::Hash>) -> FutureResult<Option<Block::Header>> {
+		self.backend.header(hash)
 	}

-	fn block(&self, hash: Option<Block::Hash>)
-		-> Result<Option<SignedBlock<Block>>>
+	fn block(&self, hash: Option<Block::Hash>) -> FutureResult<Option<SignedBlock<Block>>>
 	{
-		let hash = self.unwrap_or_best(hash)?;
-		Ok(self.client.block(&BlockId::Hash(hash)).map_err(client_error)?)
+		self.backend.block(hash)
 	}

 	fn block_hash(&self, number: Option<number::NumberOrHex<NumberFor<Block>>>) -> Result<Option<Block::Hash>> {
-		Ok(match number {
-			None => Some(self.client.info().chain.best_hash),
-			Some(num_or_hex) => self.client
-				.header(&BlockId::number(num_or_hex.to_number()?))
-				.map_err(client_error)?
-				.map(|h| h.hash()),
-		})
+		self.backend.block_hash(number)
 	}

 	fn finalized_head(&self) -> Result<Block::Hash> {
-		Ok(self.client.info().chain.finalized_hash)
+		self.backend.finalized_head()
 	}

-	fn subscribe_new_heads(&self, _metadata: Self::Metadata, subscriber: Subscriber<Block::Header>) {
-		self.subscribe_headers(
-			subscriber,
-			|| self.block_hash(None.into()),
-			|| self.client.import_notification_stream()
-				.filter(|notification| future::ready(notification.is_new_best))
-				.map(|notification| Ok::<_, ()>(notification.header))
-				.compat(),
-		)
+	fn subscribe_new_heads(&self, metadata: Self::Metadata, subscriber: Subscriber<Block::Header>) {
+		self.backend.subscribe_new_heads(metadata, subscriber)
 	}

-	fn unsubscribe_new_heads(&self, _metadata: Option<Self::Metadata>, id: SubscriptionId) -> RpcResult<bool> {
-		Ok(self.subscriptions.cancel(id))
+	fn unsubscribe_new_heads(&self, metadata: Option<Self::Metadata>, id: SubscriptionId) -> RpcResult<bool> {
+		self.backend.unsubscribe_new_heads(metadata, id)
 	}

-	fn subscribe_finalized_heads(&self, _meta: Self::Metadata, subscriber: Subscriber<Block::Header>) {
-		self.subscribe_headers(
-			subscriber,
-			|| Ok(Some(self.client.info().chain.finalized_hash)),
-			|| self.client.finality_notification_stream()
-				.map(|notification| Ok::<_, ()>(notification.header))
-				.compat(),
-		)
+	fn subscribe_finalized_heads(&self, metadata: Self::Metadata, subscriber: Subscriber<Block::Header>) {
+		self.backend.subscribe_finalized_heads(metadata, subscriber)
 	}

-	fn unsubscribe_finalized_heads(&self, _metadata: Option<Self::Metadata>, id: SubscriptionId) -> RpcResult<bool> {
-		Ok(self.subscriptions.cancel(id))
+	fn unsubscribe_finalized_heads(&self, metadata: Option<Self::Metadata>, id: SubscriptionId) -> RpcResult<bool> {
+		self.backend.unsubscribe_finalized_heads(metadata, id)
 	}
 }
+
+/// Subscribe to new headers.
+fn subscribe_headers<B, E, Block, RA, F, G, S, ERR>(
+	client: &Arc<Client<B, E, Block, RA>>,
+	subscriptions: &Subscriptions,
+	subscriber: Subscriber<Block::Header>,
+	best_block_hash: G,
+	stream: F,
+) where
+	Block: BlockT<Hash=H256> + 'static,
+	B: client::backend::Backend<Block, Blake2Hasher> + Send + Sync + 'static,
+	E: client::CallExecutor<Block, Blake2Hasher> + Send + Sync + 'static,
+	F: FnOnce() -> S,
+	G: FnOnce() -> Block::Hash,
+	ERR: ::std::fmt::Debug,
+	S: Stream<Item=Block::Header, Error=ERR> + Send + 'static,
+{
+	subscriptions.add(subscriber, |sink| {
+		// send current head right at the start.
+		let header = client.header(&BlockId::Hash(best_block_hash()))
+			.map_err(client_err)
+			.and_then(|header| {
+				header.ok_or_else(|| "Best header missing.".to_owned().into())
+			})
+			.map_err(Into::into);
+
+		// send further subscriptions
+		let stream = stream()
+			.map(|res| Ok(res))
+			.map_err(|e| warn!("Block notification stream error: {:?}", e));
+
+		sink
+			.sink_map_err(|e| warn!("Error sending notifications: {:?}", e))
+			.send_all(
+				stream::iter_result(vec![Ok(header)])
+					.chain(stream)
+			)
+			// we ignore the resulting Stream (if the first stream is over we are unsubscribed)
+			.map(|_| ())
+	});
+}
+
+fn client_err(err: client::error::Error) -> Error {
+	Error::Client(Box::new(err))
+}