new crate sc-light (#6235)

* sc-light

* remove unused deps

* fix line width

* move more fns to sc_light

substrate/Cargo.lock

@@ -6337,6 +6337,24 @@ dependencies = [
  "tempfile",
 ]
 
+[[package]]
+name = "sc-light"
+version = "2.0.0-rc3"
+dependencies = [
+ "hash-db",
+ "lazy_static",
+ "parity-scale-codec",
+ "parking_lot 0.10.2",
+ "sc-client-api",
+ "sc-executor",
+ "sp-api",
+ "sp-blockchain",
+ "sp-core",
+ "sp-externalities",
+ "sp-runtime",
+ "sp-state-machine",
+]
+
 [[package]]
 name = "sc-network"
 version = "0.8.0-rc3"
@@ -6613,6 +6631,7 @@ dependencies = [
  "sc-finality-grandpa",
  "sc-informant",
  "sc-keystore",
+ "sc-light",
  "sc-network",
  "sc-offchain",
  "sc-rpc",
@@ -6663,6 +6682,7 @@ dependencies = [
  "sc-client-api",
  "sc-client-db",
  "sc-executor",
+ "sc-light",
  "sc-network",
  "sc-service",
  "sp-api",
@@ -8069,6 +8089,7 @@ dependencies = [
  "sc-client-db",
  "sc-consensus",
  "sc-executor",
+ "sc-light",
  "sc-service",
  "sp-blockchain",
  "sp-consensus",
@@ -8130,6 +8151,7 @@ dependencies = [
  "sc-block-builder",
  "sc-client-api",
  "sc-consensus",
+ "sc-light",
  "sc-service",
  "sp-api",
  "sp-blockchain",

substrate/Cargo.toml

@@ -38,6 +38,7 @@ members = [
 	"client/executor/runtime-test",
 	"client/finality-grandpa",
 	"client/informant",
+	"client/light",
 	"client/tracing",
 	"client/keystore",
 	"client/network",

substrate/client/light/Cargo.toml

@@ -0,0 +1,27 @@
+[package]
+description = "components for a light client"
+name = "sc-light"
+version = "2.0.0-rc3"
+license = "GPL-3.0-or-later WITH Classpath-exception-2.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+edition = "2018"
+homepage = "https://substrate.dev"
+repository = "https://github.com/paritytech/substrate/"
+documentation = "https://docs.rs/sc-light"
+
+[dependencies]
+parking_lot = "0.10.0"
+lazy_static = "1.4.0"
+hash-db = "0.15.2"
+sp-runtime = { version = "2.0.0-rc2", path = "../../primitives/runtime" }
+sp-externalities = { version = "0.8.0-rc2", path = "../../primitives/externalities" }
+sp-blockchain = { version = "2.0.0-rc2", path = "../../primitives/blockchain" }
+sp-core = { version = "2.0.0-rc2", path = "../../primitives/core" }
+sp-state-machine = { version = "0.8.0-rc2", path = "../../primitives/state-machine" }
+sc-client-api = { version = "2.0.0-rc2", path = "../api" }
+sp-api = { version = "2.0.0-rc2", path = "../../primitives/api" }
+codec = { package = "parity-scale-codec", version = "1.3.0" }
+sc-executor = { version = "0.8.0-rc2", path = "../executor" }
+
+[features]
+default = []

substrate/client/light/src/blockchain.rs

@@ -25,8 +25,7 @@ use sp_runtime::{Justification, generic::BlockId};
 use sp_runtime::traits::{Block as BlockT, Header as HeaderT, NumberFor, Zero};
 
 use sp_blockchain::{
-	HeaderMetadata, CachedHeaderMetadata,
-	Error as ClientError, Result as ClientResult,
+	HeaderMetadata, CachedHeaderMetadata, Error as ClientError, Result as ClientResult,
 };
 pub use sc_client_api::{
 	backend::{
@@ -42,7 +41,7 @@ pub use sc_client_api::{
 	},
 	cht,
 };
-use super::fetcher::RemoteHeaderRequest;
+use crate::fetcher::RemoteHeaderRequest;
 
 /// Light client blockchain.
 pub struct Blockchain<S> {

substrate/client/light/src/fetcher.rs

@@ -46,8 +46,8 @@ pub use sc_client_api::{
 	},
 	cht,
 };
-use super::blockchain::{Blockchain};
-use super::call_executor::check_execution_proof;
+use crate::blockchain::Blockchain;
+use crate::call_executor::check_execution_proof;
 
 /// Remote data checker.
 pub struct LightDataChecker<E, H, B: BlockT, S: BlockchainStorage<B>> {

substrate/client/light/src/lib.rs

@@ -0,0 +1,57 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2017-2020 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+//! Light client components.
+
+use sp_runtime::traits::{Block as BlockT, HashFor};
+use sc_client_api::CloneableSpawn;
+use std::sync::Arc;
+use sp_core::traits::CodeExecutor;
+
+pub mod backend;
+pub mod blockchain;
+pub mod call_executor;
+pub mod fetcher;
+
+pub use {backend::*, blockchain::*, call_executor::*, fetcher::*};
+
+/// Create an instance of fetch data checker.
+pub fn new_fetch_checker<E, B: BlockT, S: BlockchainStorage<B>>(
+	blockchain: Arc<Blockchain<S>>,
+	executor: E,
+	spawn_handle: Box<dyn CloneableSpawn>,
+) -> LightDataChecker<E, HashFor<B>, B, S>
+	where
+		E: CodeExecutor,
+{
+	LightDataChecker::new(blockchain, executor, spawn_handle)
+}
+
+/// Create an instance of light client blockchain backend.
+pub fn new_light_blockchain<B: BlockT, S: BlockchainStorage<B>>(storage: S) -> Arc<Blockchain<S>> {
+	Arc::new(Blockchain::new(storage))
+}
+
+/// Create an instance of light client backend.
+pub fn new_light_backend<B, S>(blockchain: Arc<Blockchain<S>>) -> Arc<Backend<S, HashFor<B>>>
+	where
+		B: BlockT,
+		S: BlockchainStorage<B>,
+{
+	Arc::new(Backend::new(blockchain))
+}

substrate/client/service/Cargo.toml

@@ -55,6 +55,7 @@ sp-application-crypto = { version = "2.0.0-rc3", path = "../../primitives/applic
 sp-consensus = { version = "0.8.0-rc3", path = "../../primitives/consensus/common" }
 sc-network = { version = "0.8.0-rc3", path = "../network" }
 sc-chain-spec = { version = "2.0.0-rc3", path = "../chain-spec" }
+sc-light = { version = "2.0.0-rc3", path = "../light" }
 sc-client-api = { version = "2.0.0-rc3", path = "../api" }
 sp-api = { version = "2.0.0-rc3", path = "../../primitives/api" }
 sc-client-db = { version = "0.8.0-rc3", default-features = false, path = "../db" }

substrate/client/service/src/builder.rs

@@ -19,13 +19,14 @@
 use crate::{
 	Service, NetworkStatus, NetworkState, error::Error, DEFAULT_PROTOCOL_ID, MallocSizeOfWasm,
 	start_rpc_servers, build_network_future, TransactionPoolAdapter, TaskManager, SpawnTaskHandle,
-	status_sinks, metrics::MetricsService, client::{Client, ClientConfig},
+	status_sinks, metrics::MetricsService,
+	client::{light, Client, ClientConfig},
 	config::{Configuration, KeystoreConfig, PrometheusConfig, OffchainWorkerConfig},
 };
 use sc_client_api::{
-	BlockchainEvents, backend::RemoteBackend, light::RemoteBlockchain,
-	execution_extensions::ExtensionsFactory, ExecutorProvider, CallExecutor, ForkBlocks, BadBlocks,
-	CloneableSpawn, UsageProvider,
+	self, BlockchainEvents, light::RemoteBlockchain, execution_extensions::ExtensionsFactory,
+	ExecutorProvider, CallExecutor, ForkBlocks, BadBlocks, CloneableSpawn, UsageProvider,
+	backend::RemoteBackend,
 };
 use sp_utils::mpsc::{tracing_unbounded, TracingUnboundedSender};
 use sc_chain_spec::get_extension;
@@ -179,19 +180,19 @@ pub type TLightClient<TBl, TRtApi, TExecDisp> = Client<
 >;
 
 /// Light client backend type.
-pub type TLightBackend<TBl> = crate::client::light::backend::Backend<
+pub type TLightBackend<TBl> = sc_light::Backend<
 	sc_client_db::light::LightStorage<TBl>,
 	HashFor<TBl>,
 >;
 
 /// Light call executor type.
-pub type TLightCallExecutor<TBl, TExecDisp> = crate::client::light::call_executor::GenesisCallExecutor<
-	crate::client::light::backend::Backend<
+pub type TLightCallExecutor<TBl, TExecDisp> = sc_light::GenesisCallExecutor<
+	sc_light::Backend<
 		sc_client_db::light::LightStorage<TBl>,
 		HashFor<TBl>
 	>,
 	crate::client::LocalCallExecutor<
-		crate::client::light::backend::Backend<
+		sc_light::Backend<
 			sc_client_db::light::LightStorage<TBl>,
 			HashFor<TBl>
 		>,
@@ -415,18 +416,18 @@ impl ServiceBuilder<(), (), (), (), (), (), (), (), (), (), ()> {
 			};
 			sc_client_db::light::LightStorage::new(db_settings)?
 		};
-		let light_blockchain = crate::client::light::new_light_blockchain(db_storage);
+		let light_blockchain = sc_light::new_light_blockchain(db_storage);
 		let fetch_checker = Arc::new(
-			crate::client::light::new_fetch_checker::<_, TBl, _>(
+			sc_light::new_fetch_checker::<_, TBl, _>(
 				light_blockchain.clone(),
 				executor.clone(),
 				Box::new(task_manager.spawn_handle()),
 			),
 		);
 		let fetcher = Arc::new(sc_network::config::OnDemand::new(fetch_checker));
-		let backend = crate::client::light::new_light_backend(light_blockchain);
+		let backend = sc_light::new_light_backend(light_blockchain);
 		let remote_blockchain = backend.remote_blockchain();
-		let client = Arc::new(crate::client::light::new_light(
+		let client = Arc::new(light::new_light(
 			backend.clone(),
 			config.chain_spec.as_storage_builder(),
 			executor,

substrate/client/service/src/client/client.rs

@@ -84,10 +84,9 @@ use sp_utils::mpsc::{TracingUnboundedSender, tracing_unbounded};
 use sp_blockchain::Error;
 use prometheus_endpoint::Registry;
 use super::{
-	genesis,
-	light::{call_executor::prove_execution, fetcher::ChangesProof},
-	block_rules::{BlockRules, LookupResult as BlockLookupResult},
+	genesis, block_rules::{BlockRules, LookupResult as BlockLookupResult},
 };
+use sc_light::{call_executor::prove_execution, fetcher::ChangesProof};
 use rand::Rng;
 
 #[cfg(feature="test-helpers")]

substrate/client/service/src/client/light.rs

@@ -16,12 +16,7 @@
 // You should have received a copy of the GNU General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
-//! Light client components.
-
-pub mod backend;
-pub mod blockchain;
-pub mod call_executor;
-pub mod fetcher;
+//! Light client utilities.
 
 use std::sync::Arc;
 
@@ -37,24 +32,8 @@ use super::client::{Client,ClientConfig};
 use sc_client_api::{
 	light::Storage as BlockchainStorage, CloneableSpawn,
 };
-use self::backend::Backend;
-use self::blockchain::Blockchain;
-use self::call_executor::GenesisCallExecutor;
-use self::fetcher::LightDataChecker;
+use sc_light::{Backend, GenesisCallExecutor};
 
-/// Create an instance of light client blockchain backend.
-pub fn new_light_blockchain<B: BlockT, S: BlockchainStorage<B>>(storage: S) -> Arc<Blockchain<S>> {
-	Arc::new(Blockchain::new(storage))
-}
-
-/// Create an instance of light client backend.
-pub fn new_light_backend<B, S>(blockchain: Arc<Blockchain<S>>) -> Arc<Backend<S, HashFor<B>>>
-	where
-		B: BlockT,
-		S: BlockchainStorage<B>,
-{
-	Arc::new(Backend::new(blockchain))
-}
 
 /// Create an instance of light client.
 pub fn new_light<B, S, RA, E>(
@@ -79,7 +58,12 @@ pub fn new_light<B, S, RA, E>(
 		S: BlockchainStorage<B> + 'static,
 		E: CodeExecutor + RuntimeInfo + Clone + 'static,
 {
-	let local_executor = LocalCallExecutor::new(backend.clone(), code_executor, spawn_handle.clone(), ClientConfig::default());
+	let local_executor = LocalCallExecutor::new(
+		backend.clone(),
+		code_executor,
+		spawn_handle.clone(),
+		ClientConfig::default()
+	);
 	let executor = GenesisCallExecutor::new(backend.clone(), local_executor);
 	Client::new(
 		backend,
@@ -92,15 +76,3 @@ pub fn new_light<B, S, RA, E>(
 		ClientConfig::default(),
 	)
 }
-
-/// Create an instance of fetch data checker.
-pub fn new_fetch_checker<E, B: BlockT, S: BlockchainStorage<B>>(
-	blockchain: Arc<Blockchain<S>>,
-	executor: E,
-	spawn_handle: Box<dyn CloneableSpawn>,
-) -> LightDataChecker<E, HashFor<B>, B, S>
-	where
-		E: CodeExecutor,
-{
-	LightDataChecker::new(blockchain, executor, spawn_handle)
-}

substrate/client/service/test/Cargo.toml

@@ -20,6 +20,7 @@ log = "0.4.8"
 env_logger = "0.7.0"
 fdlimit = "0.1.4"
 parking_lot = "0.10.0"
+sc-light = { version = "2.0.0-rc3", path = "../../light" }
 sp-blockchain = { version = "2.0.0-rc3", path = "../../../primitives/blockchain" }
 sp-api = { version = "2.0.0-rc3", path = "../../../primitives/api" }
 sp-state-machine = { version = "0.8.0-rc3", path = "../../../primitives/state-machine" }

substrate/client/service/test/src/client/light.rs

@@ -16,7 +16,7 @@
 // You should have received a copy of the GNU General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
-use sc_service::client::light::{
+use sc_light::{
 	call_executor::{
 		GenesisCallExecutor,
 		check_execution_proof,

substrate/test-utils/client/Cargo.toml

@@ -13,6 +13,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 
 [dependencies]
 sc-client-api = { version = "2.0.0-rc3", path = "../../client/api" }
+sc-light = { version = "2.0.0-rc3", path = "../../client/light" }
 sc-client-db = { version = "0.8.0-rc3", features = ["test-helpers"], path = "../../client/db" }
 sp-consensus = { version = "0.8.0-rc3", path = "../../primitives/consensus/common" }
 sc-executor = { version = "0.8.0-rc3", path = "../../client/executor" }

substrate/test-utils/client/src/lib.rs

@@ -46,7 +46,7 @@ use sp_runtime::traits::{Block as BlockT, BlakeTwo256};
 use sc_service::client::{LocalCallExecutor, ClientConfig};
 
 /// Test client light database backend.
-pub type LightBackend<Block> = client::light::backend::Backend<
+pub type LightBackend<Block> = sc_light::Backend<
 	sc_client_db::light::LightStorage<Block>,
 	BlakeTwo256,
 >;

substrate/test-utils/runtime/client/Cargo.toml

@@ -12,6 +12,7 @@ publish = false
 targets = ["x86_64-unknown-linux-gnu"]
 
 [dependencies]
+sc-light = { version = "2.0.0-rc3", path = "../../../client/light" }
 sp-consensus = { version = "0.8.0-rc3", path = "../../../primitives/consensus/common" }
 sc-block-builder = { version = "0.8.0-rc3", path = "../../../client/block-builder" }
 substrate-test-client = { version = "2.0.0-rc3", path = "../../client" }

substrate/test-utils/runtime/client/src/lib.rs

@@ -35,9 +35,9 @@ use sp_core::{sr25519, ChangesTrieConfiguration};
 use sp_core::storage::{ChildInfo, Storage, StorageChild};
 use substrate_test_runtime::genesismap::{GenesisConfig, additional_storage_with_genesis};
 use sp_runtime::traits::{Block as BlockT, Header as HeaderT, Hash as HashT, NumberFor, HashFor};
-use sc_service::client::light::fetcher::{
-	Fetcher, RemoteHeaderRequest, RemoteReadRequest, RemoteReadChildRequest,
+use sc_client_api::light::{
 	RemoteCallRequest, RemoteChangesRequest, RemoteBodyRequest,
+	Fetcher, RemoteHeaderRequest, RemoteReadRequest, RemoteReadChildRequest,
 };
 
 /// A prelude to import in tests.
@@ -75,10 +75,10 @@ pub type Executor = client::LocalCallExecutor<
 pub type LightBackend = substrate_test_client::LightBackend<substrate_test_runtime::Block>;
 
 /// Test client light executor.
-pub type LightExecutor = client::light::call_executor::GenesisCallExecutor<
+pub type LightExecutor = sc_light::GenesisCallExecutor<
 	LightBackend,
 	client::LocalCallExecutor<
-		client::light::backend::Backend<
+		sc_light::Backend<
 			sc_client_db::light::LightStorage<substrate_test_runtime::Block>,
 			HashFor<substrate_test_runtime::Block>
 		>,
@@ -347,7 +347,7 @@ pub fn new_light() -> (
 ) {
 
 	let storage = sc_client_db::light::LightStorage::new_test();
-	let blockchain = Arc::new(client::light::blockchain::Blockchain::new(storage));
+	let blockchain = Arc::new(sc_light::Blockchain::new(storage));
 	let backend = Arc::new(LightBackend::new(blockchain.clone()));
 	let executor = new_native_executor();
 	let local_call_executor = client::LocalCallExecutor::new(backend.clone(), executor, sp_core::tasks::executor(), Default::default());