Merge branch 'master' into gui-candidate-justification

cumulus/.gitlab-ci.yml

@@ -36,6 +36,12 @@ variables:
     - schedules
     - web
     - /^[0-9]+$/                   # PRs
+  retry:
+    max: 2
+    when: 
+      - runner_system_failure
+      - unknown_failure
+      - api_failure
   tags:
     - linux-docker
 

cumulus/Cargo.toml

@@ -1,8 +1,13 @@
 [workspace]
 members = [
-  "consensus",
-  "runtime",
-  "network",
-  "test/runtime",
-  "test/client",
+	"consensus",
+	"network",
+	"runtime",
+	"test/runtime",
+	"test/client",
+	"test/parachain/runtime",
+	"test/parachain/",
 ]
+
+[profile.release]
+panic = 'unwind'

cumulus/README.md

@@ -10,10 +10,51 @@ Cumulus clouds are shaped sort of like dots and are up in the air, like this pro
 
 For now, this is only project contained in this repo. *cumulus-consensus* is a consensus engine for Substrate which follows a Polkadot relay chain. This will run a Polkadot node internally, and dictate to the client and synchronization algorithms which chain to follow, finalize, and treat as best.
 
-## cumulus-runtime 
+## cumulus-runtime
 
 A planned wrapper around substrate runtimes to turn them into parachain validation code and to provide proof-generation routines.
 
 ## cumulus-collator
 
-A planned Polkadot collator for the parachain.
+A planned Polkadot collator for the parachain.
+
+## Running a collator
+
+1. Checkout polkadot at `bkchr-cumulus-branch`.
+2. Build the polkadot chainspec:
+
+	`cargo run --release -- build-spec --chain=local --raw > polkadot_chainspec.json`
+
+	Open the `polkadot_chainspec.json` and replace the `bootnodes` with: `"bootNodes": [],`
+
+3. Run `Alice` and `Bob`:
+
+	`cargo run --release -- --chain=local --base-path=cumulus_relay_chain_node_0 --alice`
+
+	`cargo run --release -- --chain=local --base-path=cumulus_relay_chain_node_1 --bob --port 50666`
+
+3. Switch back to this repository and generate the parachain genesis state:
+
+	`cargo run --release -p cumulus-test-parachain-collator -- export-genesis-state genesis-state`
+
+4. Run the collator:
+
+	`cargo run --release -p cumulus-test-parachain-collator -- -d cumulus_collator_path --chain polkadot_chainspec.json --bootnodes /ip4/127.0.0.1/tcp/30333/p2p/PEER_ID`
+
+	`PEER_ID` needs to be replaced with the peer id of the polkadot validator that uses `Alice`
+	as authority.
+
+5. Open `https://polkadot.js.org/apps/#/sudo` and register the parachain.
+
+	`id`: `100`
+
+	`initial_head_data`: Use the file you generated in 3. (name: genesis-state)
+
+	`code`: `CUMULUS_REPO/target/release/wbuild/cumulus-test-parachain-runtime/cumulus_test_parachain_runtime.compact.wasm`
+
+	Now your parachain should be registered and the collator should start building blocks and sending
+	them to the relay chain.
+
+6. ...
+
+7. PROFIT!

cumulus/collator/Cargo.toml

@@ -7,6 +7,9 @@ edition = "2018"
 [dependencies]
 # Substrate dependencies
 sr-primitives = { package = "sr-primitives", git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+substrate-primitives = { git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+substrate-client = { git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+substrate-service = { git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
 consensus-common = { package = "substrate-consensus-common", git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
 inherents = { package = "substrate-inherents", git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
 cli = { package = "substrate-cli", git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
@@ -15,6 +18,10 @@ cli = { package = "substrate-cli", git = "https://github.com/paritytech/substrat
 polkadot-collator = { git = "https://github.com/paritytech/polkadot", branch = "bkchr-cumulus-branch" }
 polkadot-primitives = { git = "https://github.com/paritytech/polkadot", branch = "bkchr-cumulus-branch" }
 
+# Cumulus dependencies
+cumulus-consensus = { path = "../consensus" }
+cumulus-runtime = { path = "../runtime" }
+
 # other deps
 log = "0.4.8"
 codec = { package = "parity-scale-codec", version = "1.0.6", features = [ "derive" ] }
@@ -24,4 +31,8 @@ parking_lot = "0.9"
 
 [dev-dependencies]
 test-runtime = { package = "cumulus-test-runtime", path = "../test/runtime" }
+test-client = { package = "cumulus-test-client", path = "../test/client" }
+substrate-test-client = { git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+polkadot-executor = { git = "https://github.com/paritytech/polkadot", branch = "bkchr-cumulus-branch" }
 keyring = { package = "substrate-keyring", git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+env_logger = "0.7.1"

cumulus/collator/src/lib.rs

@@ -1,5 +1,5 @@
 // Copyright 2019 Parity Technologies (UK) Ltd.
-// This file is part of Substrate.
+// This file is part of Cumulus.
 
 // Substrate is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -16,15 +16,22 @@
 
 //! Cumulus Collator implementation for Substrate.
 
-use sr_primitives::traits::Block as BlockT;
-use consensus_common::{Environment, Proposer};
+use cumulus_runtime::ParachainBlockData;
+
+use sr_primitives::traits::{Block as BlockT, Header as HeaderT};
+use consensus_common::{
+	BlockImport, Environment, Proposer, ForkChoiceStrategy, BlockImportParams, BlockOrigin,
+	Error as ConsensusError,
+};
 use inherents::InherentDataProviders;
+use substrate_primitives::Blake2Hasher;
 
 use polkadot_collator::{
 	InvalidHead, ParachainContext, BuildParachainContext, Network as CollatorNetwork, VersionInfo,
+	TaskExecutor, PolkadotClient,
 };
 use polkadot_primitives::{
-	Hash,
+	Hash as PHash, Block as PBlock,
 	parachain::{
 		self, BlockData, Message, Id as ParaId, OutgoingMessages, Status as ParachainStatus,
 		CollatorPair,
@@ -33,12 +40,12 @@ use polkadot_primitives::{
 
 use codec::{Decode, Encode};
 
-use log::error;
+use log::{error, trace};
 
-use futures03::TryFutureExt;
+use futures03::{TryFutureExt, future};
 use futures::{Future, future::IntoFuture};
 
-use std::{sync::Arc, marker::PhantomData, time::Duration};
+use std::{sync::Arc, marker::PhantomData, time::Duration, fmt::Debug};
 
 use parking_lot::Mutex;
 
@@ -49,100 +56,184 @@ struct HeadData<Block: BlockT> {
 }
 
 /// The implementation of the Cumulus `Collator`.
-pub struct Collator<Block, PF> {
+pub struct Collator<Block, PF, BI> {
 	proposer_factory: Arc<Mutex<PF>>,
 	_phantom: PhantomData<Block>,
 	inherent_data_providers: InherentDataProviders,
 	collator_network: Arc<dyn CollatorNetwork>,
+	block_import: Arc<Mutex<BI>>,
 }
 
-impl<Block: BlockT, PF: Environment<Block>> Collator<Block, PF> {
+impl<Block, PF, BI> Collator<Block, PF, BI> {
 	/// Create a new instance.
 	fn new(
 		proposer_factory: PF,
 		inherent_data_providers: InherentDataProviders,
 		collator_network: Arc<dyn CollatorNetwork>,
+		block_import: BI,
 	) -> Self {
 		Self {
 			proposer_factory: Arc::new(Mutex::new(proposer_factory)),
 			inherent_data_providers,
 			_phantom: PhantomData,
 			collator_network,
+			block_import: Arc::new(Mutex::new(block_import)),
 		}
 	}
 }
 
-impl<Block, PF> Clone for Collator<Block, PF> {
+impl<Block, PF, BI> Clone for Collator<Block, PF, BI> {
 	fn clone(&self) -> Self {
 		Self {
 			proposer_factory: self.proposer_factory.clone(),
 			inherent_data_providers: self.inherent_data_providers.clone(),
 			_phantom: PhantomData,
 			collator_network: self.collator_network.clone(),
+			block_import: self.block_import.clone(),
 		}
 	}
 }
 
-impl<Block, PF> ParachainContext for Collator<Block, PF> where
-	Block: BlockT,
-	PF: Environment<Block> + 'static + Send + Sync,
-	PF::Error: std::fmt::Debug,
-	PF::Proposer: Send + Sync,
-	<PF::Proposer as Proposer<Block>>::Create: Unpin + Send + Sync,
+impl<Block, PF, BI> ParachainContext for Collator<Block, PF, BI>
+	where
+		Block: BlockT,
+		PF: Environment<Block> + 'static + Send,
+		BI: BlockImport<Block, Error=ConsensusError> + Send + Sync + 'static,
 {
 	type ProduceCandidate = Box<
 		dyn Future<Item=(BlockData, parachain::HeadData, OutgoingMessages), Error=InvalidHead>
-			+ Send + Sync
+			+ Send
 	>;
 
 	fn produce_candidate<I: IntoIterator<Item=(ParaId, Message)>>(
-		&self,
-		_relay_chain_parent: Hash,
+		&mut self,
+		_relay_chain_parent: PHash,
 		status: ParachainStatus,
 		_: I,
 	) -> Self::ProduceCandidate {
+		trace!(target: "cumulus-collator", "Producing candidate");
+
 		let factory = self.proposer_factory.clone();
 		let inherent_providers = self.inherent_data_providers.clone();
+		let block_import = self.block_import.clone();
 
 		let res = HeadData::<Block>::decode(&mut &status.head_data.0[..])
-			.map_err(|_| InvalidHead)
+			.map_err(|e| {
+				error!(target: "cumulus-collator", "Could not decode the head data: {:?}", e);
+				InvalidHead
+			})
 			.into_future()
-			.and_then(move |last_head|
+			.and_then(move |last_head| {
+				let parent_state_root = *last_head.header.state_root();
+
 				factory.lock()
 					.init(&last_head.header)
 					.map_err(|e| {
-						//TODO: Do we want to return the real error?
-						error!("Could not create proposer: {:?}", e);
+						error!(
+							target: "cumulus-collator",
+							"Could not create proposer: {:?}",
+							e,
+						);
 						InvalidHead
 					})
-			)
-			.and_then(move |proposer|
-				inherent_providers.create_inherent_data()
-					.map(|id| (proposer, id))
-					.map_err(|e| {
-						error!("Failed to create inherent data: {:?}", e);
-						InvalidHead
+					.and_then(|mut proposer| {
+						let inherent_data = inherent_providers.create_inherent_data()
+							.map_err(|e| {
+								error!(
+								target: "cumulus-collator",
+									"Failed to create inherent data: {:?}",
+									e,
+								);
+								InvalidHead
+							})?;
+
+						let future = proposer.propose(
+							inherent_data,
+							Default::default(),
+							//TODO: Fix this.
+							Duration::from_secs(6),
+							true,
+						)
+						.map_err(|e| {
+							error!(
+								target: "cumulus-collator",
+								"Proposing failed: {:?}",
+								e,
+							);
+							InvalidHead
+						})
+						.and_then(move |(block, proof)| {
+							let res = match proof {
+								Some(proof) => {
+									let (header, extrinsics) = block.deconstruct();
+
+									// Create the parachain block data for the validators.
+									Ok(
+										ParachainBlockData::<Block>::new(
+											header,
+											extrinsics,
+											proof,
+											parent_state_root,
+										)
+									)
+								}
+								None => {
+									error!(
+										target: "cumulus-collator",
+										"Proposer did not return the requested proof.",
+									);
+									Err(InvalidHead)
+								}
+							};
+
+							future::ready(res)
+						})
+						.compat();
+
+						Ok(future)
 					})
-			)
-			.and_then(|(mut proposer, inherent_data)| {
-				proposer.propose(
-					inherent_data,
+			})
+			.flatten()
+			.and_then(move |b| {
+				let block_import_params = BlockImportParams {
+					origin: BlockOrigin::Own,
+					header: b.header().clone(),
+					justification: None,
+					post_digests: vec![],
+					body: Some(b.extrinsics().to_vec()),
+					finalized: false,
+					auxiliary: vec![], // block-weight is written in block import.
+					// TODO: block-import handles fork choice and this shouldn't even have the
+					// option to specify one.
+					// https://github.com/paritytech/substrate/issues/3623
+					fork_choice: ForkChoiceStrategy::LongestChain,
+				};
+
+				if let Err(err) = block_import.lock().import_block(
+					block_import_params,
 					Default::default(),
-					//TODO: Fix this.
-					Duration::from_secs(6),
-				)
-				.map_err(|e| {
-					error!("Proposing failed: {:?}", e);
-					InvalidHead
-				})
-				.compat()
+				) {
+					error!(
+						target: "cumulus-collator",
+						"Error importing build block (at {:?}): {:?}",
+						b.header().parent_hash(),
+						err,
+					);
+					Err(InvalidHead)
+				} else {
+					Ok(b)
+				}
 			})
 			.map(|b| {
 				let block_data = BlockData(b.encode());
-				let head_data = HeadData::<Block> { header: b.deconstruct().0 };
+				let head_data = HeadData::<Block> { header: b.into_header() };
 				let messages = OutgoingMessages { outgoing_messages: Vec::new() };
 
 				(block_data, parachain::HeadData(head_data.encode()), messages)
+			})
+			.then(|r| {
+				trace!(target: "cumulus-collator", "Produced candidate: {:?}", r);
+				r
 			});
 
 		Box::new(res)
@@ -150,41 +241,60 @@ impl<Block, PF> ParachainContext for Collator<Block, PF> where
 }
 
 /// Implements `BuildParachainContext` to build a collator instance.
-struct CollatorBuilder<Block, PF> {
-	inherent_data_providers: InherentDataProviders,
-	proposer_factory: PF,
-	_phantom: PhantomData<Block>,
+struct CollatorBuilder<Block, SP> {
+	setup_parachain: SP,
+	_marker: PhantomData<Block>,
 }
 
-impl<Block, PF> CollatorBuilder<Block, PF> {
+impl<Block, SP> CollatorBuilder<Block, SP> {
 	/// Create a new instance of self.
-	fn new(proposer_factory: PF, inherent_data_providers: InherentDataProviders) -> Self {
+	fn new(setup_parachain: SP) -> Self {
 		Self {
-			inherent_data_providers,
-			proposer_factory,
-			_phantom: Default::default(),
+			setup_parachain,
+			_marker: PhantomData,
 		}
 	}
 }
 
-impl<Block, PF> BuildParachainContext for CollatorBuilder<Block, PF> where
-	Block: BlockT,
-	PF: Environment<Block> + 'static + Send + Sync,
-	PF::Error: std::fmt::Debug,
-	PF::Proposer: Send + Sync,
-	<PF::Proposer as Proposer<Block>>::Create: Unpin + Send + Sync,
-{
-	type ParachainContext = Collator<Block, PF>;
+impl<Block: BlockT, SP: SetupParachain<Block>> BuildParachainContext for CollatorBuilder<Block, SP> {
+	type ParachainContext = Collator<Block, SP::ProposerFactory, SP::BlockImport>;
 
-	fn build(self, network: Arc<dyn CollatorNetwork>) -> Result<Self::ParachainContext, ()> {
-		Ok(Collator::new(self.proposer_factory, self.inherent_data_providers, network))
+	fn build<B, E>(
+		self,
+		client: Arc<PolkadotClient<B, E>>,
+		task_executor: TaskExecutor,
+		network: Arc<dyn CollatorNetwork>,
+	) -> Result<Self::ParachainContext, ()>
+		where
+			B: substrate_client::backend::Backend<PBlock, Blake2Hasher> + 'static,
+			E: substrate_client::CallExecutor<PBlock, Blake2Hasher> + Clone + Send + Sync + 'static
+	{
+		let (proposer_factory, block_import, inherent_data_providers) = self.setup_parachain
+			.setup_parachain(client, task_executor)
+			.map_err(|e| error!("Error setting up the parachain: {}", e))?;
+
+		Ok(Collator::new(proposer_factory, inherent_data_providers, network, block_import))
 	}
 }
 
+/// Something that can setup a parachain.
+pub trait SetupParachain<Block: BlockT>: Send {
+	/// The proposer factory of the parachain to build blocks.
+	type ProposerFactory: Environment<Block> + Send + 'static;
+	/// The block import for importing the blocks build by the collator.
+	type BlockImport: BlockImport<Block, Error=ConsensusError> + Send + Sync + 'static;
+
+	/// Setup the parachain.
+	fn setup_parachain<P: cumulus_consensus::PolkadotClient>(
+		self,
+		polkadot_client: P,
+		task_executor: TaskExecutor,
+	) -> Result<(Self::ProposerFactory, Self::BlockImport, InherentDataProviders), String>;
+}
+
 /// Run a collator with the given proposer factory.
-pub fn run_collator<Block, PF, E, I>(
-	proposer_factory: PF,
-	inherent_data_providers: InherentDataProviders,
+pub fn run_collator<Block, SP, E>(
+	setup_parachain: SP,
 	para_id: ParaId,
 	exit: E,
 	key: Arc<CollatorPair>,
@@ -192,14 +302,11 @@ pub fn run_collator<Block, PF, E, I>(
 ) -> Result<(), cli::error::Error>
 where
 	Block: BlockT,
-	PF: Environment<Block> + 'static + Send + Sync,
-	PF::Error: std::fmt::Debug,
-	PF::Proposer: Send + Sync,
-	<PF::Proposer as Proposer<Block>>::Create: Unpin + Send + Sync,
+	SP: SetupParachain<Block> + Send + 'static,
 	E: IntoFuture<Item=(), Error=()>,
 	E::Future: Send + Clone + Sync + 'static,
 {
-	let builder = CollatorBuilder::new(proposer_factory, inherent_data_providers);
+	let builder = CollatorBuilder::new(setup_parachain);
 	polkadot_collator::run_collator(builder, para_id, exit, key, version)
 }
 
@@ -212,10 +319,13 @@ mod tests {
 	use polkadot_primitives::parachain::{ConsolidatedIngress, HeadData, FeeSchedule};
 
 	use keyring::Sr25519Keyring;
-	use sr_primitives::traits::{DigestFor, Header as HeaderT};
+	use sr_primitives::{generic::BlockId, traits::{DigestFor, Header as HeaderT}};
 	use inherents::InherentData;
+	use substrate_client::error::Result as ClientResult;
+	use substrate_test_client::{NativeExecutor, WasmExecutionMethod::Interpreted};
 
 	use test_runtime::{Block, Header};
+	use test_client::{Client, DefaultTestClientBuilderExt, TestClientBuilder, TestClientBuilderExt};
 
 	use futures03::future;
 	use futures::Stream;
@@ -244,14 +354,15 @@ mod tests {
 
 	impl Proposer<Block> for DummyProposer {
 		type Error = Error;
-		type Create = future::Ready<Result<Block, Error>>;
+		type Proposal = future::Ready<Result<(Block, Option<Vec<Vec<u8>>>), Error>>;
 
 		fn propose(
 			&mut self,
 			_: InherentData,
 			digest : DigestFor<Block>,
 			_: Duration,
-		) -> Self::Create {
+			_: bool,
+		) -> Self::Proposal {
 			let header = Header::new(
 				1337,
 				Default::default(),
@@ -260,7 +371,7 @@ mod tests {
 				digest,
 			);
 
-			future::ready(Ok(Block::new(header, Vec::new())))
+			future::ready(Ok((Block::new(header, Vec::new()), Some(Default::default()))))
 		}
 	}
 
@@ -273,7 +384,7 @@ mod tests {
 			unimplemented!("Not required in tests")
 		}
 
-		fn checked_statements(&self, _: Hash) ->
+		fn checked_statements(&self, _: PHash) ->
 			Box<dyn Stream<Item=SignedStatement, Error=()>>
 		{
 			unimplemented!("Not required in tests")
@@ -291,10 +402,71 @@ mod tests {
 		}
 	}
 
+	#[derive(Clone)]
+	struct DummyPolkadotClient;
+
+	impl cumulus_consensus::PolkadotClient for DummyPolkadotClient {
+		type Error = Error;
+		type Finalized = Box<dyn futures03::Stream<Item=Vec<u8>> + Send + Unpin>;
+
+		fn finalized_heads(&self, _: ParaId) -> ClientResult<Self::Finalized> {
+			unimplemented!("Not required in tests")
+		}
+
+		fn parachain_head_at(
+			&self,
+			_: &BlockId<PBlock>,
+			_: ParaId,
+		) -> ClientResult<Option<Vec<u8>>>{
+			unimplemented!("Not required in tests")
+		}
+	}
+
+	struct DummySetup;
+
+	impl SetupParachain<Block> for DummySetup {
+		type ProposerFactory = DummyFactory;
+		type BlockImport = Client;
+
+		fn setup_parachain<P: cumulus_consensus::PolkadotClient>(
+			self,
+			_: P,
+			_: TaskExecutor,
+		) -> Result<(Self::ProposerFactory, Self::BlockImport, InherentDataProviders), String> {
+			Ok((DummyFactory, TestClientBuilder::new().build(), InherentDataProviders::default()))
+		}
+	}
+
+	type BoxFuture = Box<dyn Future<Item = (), Error = ()> + Send>;
+
+	struct DummyFutureExecutor;
+
+	impl futures::future::Executor<BoxFuture>
+		for DummyFutureExecutor
+	{
+		fn execute(
+			&self,
+			_: BoxFuture,
+		) -> Result<(), futures::future::ExecuteError<BoxFuture>> {
+			unimplemented!("Not required in tests")
+		}
+	}
+
 	#[test]
 	fn collates_produces_a_block() {
-		let builder = CollatorBuilder::new(DummyFactory, InherentDataProviders::new());
-		let context = builder.build(Arc::new(DummyCollatorNetwork)).expect("Creates parachain context");
+		let _ = env_logger::try_init();
+
+		let builder = CollatorBuilder::new(DummySetup);
+		let context = builder.build(
+			Arc::new(
+				substrate_test_client::TestClientBuilder::<_, _, ()>::default()
+					.build_with_native_executor(
+						Some(NativeExecutor::<polkadot_executor::Executor>::new(Interpreted, None)),
+					).0
+			),
+			Arc::new(DummyFutureExecutor),
+			Arc::new(DummyCollatorNetwork),
+		).expect("Creates parachain context");
 
 		let id = ParaId::from(100);
 		let header = Header::new(

cumulus/consensus/Cargo.toml

@@ -10,6 +10,7 @@ edition = "2018"
 substrate-client = { git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
 substrate-consensus-common = { git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
 substrate-primitives = { git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+substrate-inherents = { git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
 sr-primitives = { git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
 
 # polkadot deps

cumulus/consensus/src/import_queue.rs

@@ -0,0 +1,125 @@
+// Copyright 2019 Parity Technologies (UK) Ltd.
+// This file is part of Cumulus.
+
+// Cumulus 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.
+
+// Cumulus 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 Cumulus.  If not, see <http://www.gnu.org/licenses/>.
+
+use std::sync::Arc;
+
+use substrate_primitives::{H256, Blake2Hasher};
+
+use sr_primitives::{
+	traits::{Block as BlockT, ProvideRuntimeApi, Header as HeaderT}, Justification,
+	generic::BlockId,
+};
+
+use substrate_client::{
+	block_builder::api::BlockBuilder as BlockBuilderApi, backend::Backend, CallExecutor, Client,
+	error::Result as ClientResult,
+};
+
+use substrate_consensus_common::{
+	import_queue::{Verifier as VerifierT, BasicQueue, CacheKeyId}, BlockImportParams,
+	ForkChoiceStrategy, BlockOrigin, error::Error as ConsensusError, BlockImport,
+};
+
+use substrate_inherents::InherentDataProviders;
+
+/// A verifier that just checks the inherents.
+struct Verifier<B, E, Block: BlockT, RA> {
+	client: Arc<Client<B, E, Block, RA>>,
+	inherent_data_providers: InherentDataProviders,
+}
+
+impl<B, E, Block, RA> VerifierT<Block> for Verifier<B, E, Block, RA> where
+	Block: BlockT<Hash=H256>,
+	B: Backend<Block, Blake2Hasher> + 'static,
+	E: CallExecutor<Block, Blake2Hasher> + 'static + Clone + Send + Sync,
+	RA: Send + Sync,
+	Client<B, E, Block, RA>: ProvideRuntimeApi + Send + Sync,
+	<Client<B, E, Block, RA> as ProvideRuntimeApi>::Api: BlockBuilderApi<Block>
+{
+	fn verify(
+		&mut self,
+		origin: BlockOrigin,
+		header: Block::Header,
+		justification: Option<Justification>,
+		mut body: Option<Vec<Block::Extrinsic>>,
+	) -> Result<(BlockImportParams<Block>, Option<Vec<(CacheKeyId, Vec<u8>)>>), String> {
+		if let Some(inner_body) = body.take() {
+			let inherent_data = self.inherent_data_providers
+				.create_inherent_data()
+				.map_err(String::from)?;
+
+			let block = Block::new(header.clone(), inner_body);
+
+			let inherent_res = self.client.runtime_api().check_inherents(
+				&BlockId::Hash(*header.parent_hash()),
+				block.clone(),
+				inherent_data,
+			).map_err(|e| format!("{:?}", e))?;
+
+			if !inherent_res.ok() {
+				inherent_res
+					.into_errors()
+					.try_for_each(|(i, e)| {
+						Err(self.inherent_data_providers.error_to_string(&i, &e))
+					})?;
+			}
+
+			let (_, inner_body) = block.deconstruct();
+			body = Some(inner_body);
+		}
+
+
+		let block_import_params = BlockImportParams {
+			origin,
+			header,
+			post_digests: Vec::new(),
+			body,
+			finalized: false,
+			justification,
+			auxiliary: Vec::new(),
+			fork_choice: ForkChoiceStrategy::LongestChain,
+		};
+
+		Ok((block_import_params, None))
+	}
+}
+
+/// Start an import queue for a Cumulus collator that does not uses any special authoring logic.
+pub fn import_queue<B, E, Block: BlockT<Hash=H256>, I, RA>(
+	client: Arc<Client<B, E, Block, RA>>,
+	block_import: I,
+	inherent_data_providers: InherentDataProviders,
+) -> ClientResult<BasicQueue<Block>>
+	where
+		B: Backend<Block, Blake2Hasher> + 'static,
+		I: BlockImport<Block,Error=ConsensusError> + Send + Sync + 'static,
+		E: CallExecutor<Block, Blake2Hasher> + Clone + Send + Sync + 'static,
+		RA: Send + Sync + 'static,
+		Client<B, E, Block, RA>: ProvideRuntimeApi + Send + Sync + 'static,
+		<Client<B, E, Block, RA> as ProvideRuntimeApi>::Api: BlockBuilderApi<Block>,
+{
+	let verifier = Verifier {
+		client,
+		inherent_data_providers
+	};
+
+	Ok(BasicQueue::new(
+		verifier,
+		Box::new(block_import),
+		None,
+		None,
+	))
+}

cumulus/consensus/src/lib.rs

@@ -35,6 +35,8 @@ use log::warn;
 
 use std::{sync::Arc, marker::PhantomData};
 
+pub mod import_queue;
+
 /// Helper for the local client.
 pub trait LocalClient {
 	/// The block type of the local client.
@@ -64,12 +66,12 @@ pub struct HeadUpdate {
 
 /// Helper for the Polkadot client. This is expected to be a lightweight handle
 /// like an `Arc`.
-pub trait PolkadotClient: Clone {
+pub trait PolkadotClient: Clone + 'static {
 	/// The error type for interacting with the Polkadot client.
 	type Error: std::fmt::Debug + Send;
 
 	/// A stream that yields finalized head-data for a certain parachain.
-	type Finalized: Stream<Item = Vec<u8>> + Send;
+	type Finalized: Stream<Item = Vec<u8>> + Send + Unpin;
 
 	/// Get a stream of finalized heads.
 	fn finalized_heads(&self, para_id: ParaId) -> ClientResult<Self::Finalized>;
@@ -83,11 +85,11 @@ pub trait PolkadotClient: Clone {
 }
 
 /// Spawns a future that follows the Polkadot relay chain for the given parachain.
-pub fn follow_polkadot<'a, L: 'a, P: 'a>(para_id: ParaId, local: Arc<L>, polkadot: P)
-	-> ClientResult<impl Future<Output = ()> + Send + 'a>
+pub fn follow_polkadot<L, P>(para_id: ParaId, local: Arc<L>, polkadot: P)
+	-> ClientResult<impl Future<Output = ()> + Send + Unpin>
 	where
 		L: LocalClient + Send + Sync,
-		P: PolkadotClient + Send + Sync,
+		P: PolkadotClient,
 {
 	let finalized_heads = polkadot.finalized_heads(para_id)?;
 

cumulus/runtime/src/lib.rs

@@ -41,6 +41,7 @@ pub struct ParachainBlockData<B: BlockT> {
 	extrinsics: Vec<<B as BlockT>::Extrinsic>,
 	/// The data that is required to emulate the storage accesses executed by all extrinsics.
 	witness_data: WitnessData,
+	/// The storage root of the witness data.
 	witness_data_storage_root: <B as BlockT>::Hash,
 }
 
@@ -58,4 +59,19 @@ impl<B: BlockT> ParachainBlockData<B> {
 			witness_data_storage_root,
 		}
 	}
-}
+
+	/// Convert `self` into the stored header.
+	pub fn into_header(self) -> B::Header {
+		self.header
+	}
+
+	/// Returns the header.
+	pub fn header(&self) -> &B::Header {
+		&self.header
+	}
+
+	/// Returns the extrinsics.
+	pub fn extrinsics(&self) -> &[B::Extrinsic] {
+		&self.extrinsics
+	}
+}

cumulus/runtime/src/validate_block/implementation.rs

@@ -27,7 +27,7 @@ use rstd::{slice, ptr, cmp, vec::Vec, boxed::Box, mem};
 
 use hash_db::{HashDB, EMPTY_PREFIX};
 
-use parachain::ValidationParams;
+use parachain::{ValidationParams, ValidationResult};
 
 static mut STORAGE: Option<Box<dyn Storage>> = None;
 /// The message to use as expect message while accessing the `STORAGE`.
@@ -54,13 +54,15 @@ trait Storage {
 #[doc(hidden)]
 pub fn validate_block<B: BlockT<Hash = H256>, E: ExecuteBlock<B>>(
 	params: ValidationParams,
-) {
-	use codec::Decode;
+) -> ValidationResult {
+	use codec::{Decode, Encode};
 
 	let block_data = crate::ParachainBlockData::<B>::decode(&mut &params.block_data[..])
 		.expect("Invalid parachain block data");
 
 	let parent_head = B::Header::decode(&mut &params.parent_head[..]).expect("Invalid parent head");
+	// TODO: Use correct head data
+	let head_data = block_data.header.encode();
 
 	// TODO: Add `PolkadotInherent`.
 	let block = B::new(block_data.header, block_data.extrinsics);
@@ -85,6 +87,8 @@ pub fn validate_block<B: BlockT<Hash = H256>, E: ExecuteBlock<B>>(
 	};
 
 	E::execute_block(block);
+
+	ValidationResult { head_data }
 }
 
 /// The storage implementation used when validating a block that is using the
@@ -141,16 +145,17 @@ impl<B: BlockT<Hash = H256>> Storage for WitnessStorage<B> {
 		let root = match delta_trie_root::<Layout<Blake2Hasher>, _, _, _, _>(
 			&mut self.witness_data,
 			self.storage_root.clone(),
-			self.overlay.drain()
+			self.overlay.drain(),
 		) {
 			Ok(root) => root,
-			Err(_) => return [0; STORAGE_ROOT_LEN],
+			Err(e) => match *e {
+				trie_db::TrieError::InvalidStateRoot(_) => panic!("Invalid state root"),
+				trie_db::TrieError::IncompleteDatabase(_) => panic!("IncompleteDatabase"),
+				trie_db::TrieError::DecoderError(_, _) => panic!("DecodeError"),
+			}
 		};
 
-		assert!(root.as_ref().len() <= STORAGE_ROOT_LEN);
-		let mut res = [0; STORAGE_ROOT_LEN];
-		res.copy_from_slice(root.as_ref());
-		res
+		root.into()
 	}
 }
 

cumulus/runtime/src/validate_block/mod.rs

@@ -63,15 +63,17 @@ macro_rules! register_validate_block_impl {
 			unsafe fn validate_block(
 				arguments: *const u8,
 				arguments_len: usize,
-			) {
+			) -> u64 {
 				let params = $crate::validate_block::parachain::wasm_api::load_params(
 					arguments,
 					arguments_len,
 				);
 
-				$crate::validate_block::implementation::validate_block::<
+				let res = $crate::validate_block::implementation::validate_block::<
 					$block, $block_executor
 				>(params);
+
+				$crate::validate_block::parachain::wasm_api::write_result(res)
 			}
 		}
 	};
@@ -83,4 +85,4 @@ macro_rules! register_validate_block_impl {
 #[macro_export]
 macro_rules! register_validate_block_impl {
 	($block:ty, $block_executor:ty) => {};
-}
+}

cumulus/runtime/src/validate_block/tests.rs

@@ -19,46 +19,38 @@ use crate::{ParachainBlockData, WitnessData};
 use rio::TestExternalities;
 use keyring::AccountKeyring;
 use runtime_primitives::{generic::BlockId, traits::{Block as BlockT, Header as HeaderT}};
-use executor::{WasmExecutor, error::Result, wasmi::RuntimeValue::I32};
+use executor::{call_in_wasm, error::Result, WasmExecutionMethod};
 use test_client::{
 	TestClientBuilder, TestClientBuilderExt, DefaultTestClientBuilderExt, Client, LongestChain,
 	runtime::{Block, Transfer, Hash, WASM_BINARY, Header}
 };
 use consensus_common::SelectChain;
-use parachain::ValidationParams;
+use parachain::{ValidationParams, ValidationResult};
 
-use codec::Encode;
+use codec::{Encode, Decode};
 
-fn call_validate_block(parent_head: Header, block_data: ParachainBlockData<Block>) -> Result<()> {
+fn call_validate_block(
+	parent_head: Header,
+	block_data: ParachainBlockData<Block>,
+) -> Result<Header> {
 	let mut ext = TestExternalities::default();
-	WasmExecutor::new().call_with_custom_signature(
-		&mut ext,
-		1024,
-		&WASM_BINARY,
-		"validate_block",
-		|alloc| {
-			let params = ValidationParams {
-				block_data: block_data.encode(),
-				parent_head: parent_head.encode(),
-				ingress: Vec::new(),
-			}.encode();
-			let params_offset = alloc(&params)?;
+	let mut ext_ext = ext.ext();
+	let params = ValidationParams {
+		block_data: block_data.encode(),
+		parent_head: parent_head.encode(),
+		ingress: Vec::new(),
+	}.encode();
 
-			Ok(
-				vec![
-					I32(params_offset as i32),
-					I32(params.len() as i32),
-				]
-			)
-		},
-		|res, _| {
-			if res.is_none() {
-				Ok(Some(()))
-			} else {
-				Ok(None)
-			}
-		}
+	call_in_wasm(
+		"validate_block",
+		&params,
+		WasmExecutionMethod::Interpreted,
+		&mut ext_ext,
+		&WASM_BINARY,
+		1024,
 	)
+	.map(|v| ValidationResult::decode(&mut &v[..]).expect("Decode `ValidationResult`."))
+	.map(|v| Header::decode(&mut &v.head_data[..]).expect("Decode `Header`."))
 }
 
 fn create_extrinsics() -> Vec<<Block as BlockT>::Extrinsic> {
@@ -99,9 +91,10 @@ fn build_block_with_proof(
 	extrinsics: Vec<<Block as BlockT>::Extrinsic>,
 ) -> (Block, WitnessData) {
 	let block_id = BlockId::Hash(client.info().chain.best_hash);
-	let mut builder = client.new_block_at_with_proof_recording(
+	let mut builder = client.new_block_at(
 		&block_id,
-		Default::default()
+		Default::default(),
+		true,
 	).expect("Initializes new block");
 
 	extrinsics.into_iter().for_each(|e| builder.push(e).expect("Pushes an extrinsic"));
@@ -122,12 +115,14 @@ fn validate_block_with_no_extrinsics() {
 	let (header, extrinsics) = block.deconstruct();
 
 	let block_data = ParachainBlockData::new(
-		header,
+		header.clone(),
 		extrinsics,
 		witness_data,
 		witness_data_storage_root
 	);
-	call_validate_block(parent_head, block_data).expect("Calls `validate_block`");
+
+	let res_header = call_validate_block(parent_head, block_data).expect("Calls `validate_block`");
+	assert_eq!(header, res_header);
 }
 
 #[test]
@@ -139,12 +134,14 @@ fn validate_block_with_extrinsics() {
 	let (header, extrinsics) = block.deconstruct();
 
 	let block_data = ParachainBlockData::new(
-		header,
+		header.clone(),
 		extrinsics,
 		witness_data,
 		witness_data_storage_root
 	);
-	call_validate_block(parent_head, block_data).expect("Calls `validate_block`");
+
+	let res_header = call_validate_block(parent_head, block_data).expect("Calls `validate_block`");
+	assert_eq!(header, res_header);
 }
 
 #[test]

cumulus/test/parachain/Cargo.toml

@@ -0,0 +1,52 @@
+[package]
+name = 'cumulus-test-parachain-collator'
+version = '0.1.0'
+authors = ["Parity Technologies <admin@parity.io>"]
+build = 'build.rs'
+edition = '2018'
+
+[[bin]]
+name = 'cumulus-test-parachain-collator'
+path = 'src/main.rs'
+
+[dependencies]
+derive_more = '0.15.0'
+exit-future = '0.1.4'
+futures = '0.1.29'
+futures03 = { package = "futures-preview", version = "0.3.0-alpha.19", features = ["compat"] }
+log = '0.4.8'
+parking_lot = '0.9.0'
+tokio = '0.1.22'
+trie-root = '0.15.2'
+codec = { package = 'parity-scale-codec', version = '1.0.0' }
+parachain-runtime = { package = "cumulus-test-parachain-runtime", path = "runtime" }
+structopt = "0.3.3"
+ctrlc = { version = "3.1.3", features = ["termination"] }
+
+# Substrate dependencies
+sr-primitives = { git = "https://github.com/paritytech/substrate", default_features = false, branch = "bkchr-cumulus-branch" }
+sr-io = { git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+substrate-cli = { git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+substrate-primitives = { package = "substrate-primitives", git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+substrate-executor = { git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+substrate-service = { git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+inherents = { package = "substrate-inherents", git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+transaction-pool = { package = "substrate-transaction-pool", git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+network = { package = "substrate-network", git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+substrate-client = { git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+srml-timestamp = { git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+basic-authorship = { package = "substrate-basic-authorship", git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+consensus-common = { package = "substrate-consensus-common", git = "https://github.com/paritytech/substrate", branch = "bkchr-cumulus-branch" }
+
+# Cumulus dependencies
+cumulus-consensus = { path = "../../consensus" }
+cumulus-collator = { path = "../../collator" }
+
+# Polkadot dependencies
+polkadot-primitives = { git = "https://github.com/paritytech/polkadot", branch = "bkchr-cumulus-branch" }
+polkadot-collator = { git = "https://github.com/paritytech/polkadot", branch = "bkchr-cumulus-branch" }
+
+[build-dependencies]
+vergen = '3.0.4'
+
+

cumulus/test/parachain/build.rs

@@ -0,0 +1,40 @@
+// Copyright 2019 Parity Technologies (UK) Ltd.
+// This file is part of Cumulus.
+
+// Substrate 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.
+
+// Substrate 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 Cumulus.  If not, see <http://www.gnu.org/licenses/>.
+
+use std::{env, path::PathBuf};
+
+use vergen::{ConstantsFlags, generate_cargo_keys};
+
+const ERROR_MSG: &str = "Failed to generate metadata files";
+
+fn main() {
+	generate_cargo_keys(ConstantsFlags::SHA_SHORT).expect(ERROR_MSG);
+
+	let mut manifest_dir = PathBuf::from(
+		env::var("CARGO_MANIFEST_DIR").expect("`CARGO_MANIFEST_DIR` is always set by cargo.")
+	);
+
+	while manifest_dir.parent().is_some() {
+		if manifest_dir.join(".git/HEAD").exists() {
+			println!("cargo:rerun-if-changed={}", manifest_dir.join(".git/HEAD").display());
+			return
+		}
+
+		manifest_dir.pop();
+	}
+
+	println!("cargo:warning=Could not find `.git/HEAD` from manifest dir!");
+}

cumulus/test/parachain/runtime/Cargo.toml

@@ -0,0 +1,61 @@
+[package]
+name = 'cumulus-test-parachain-runtime'
+version = '0.1.0'
+authors = ["Parity Technologies <admin@parity.io>"]
+edition = '2018'
+
+[dependencies]
+serde = { version = "1.0.101", optional = true, features = ["derive"] }
+safe-mix = { version = "1.0.0", default-features = false }
+codec = { package = "parity-scale-codec", version = "1.0.6", default-features = false, features = ["derive"] }
+
+# Substrate dependencies
+rstd = { package = "sr-std", git = "https://github.com/paritytech/substrate", default_features = false, branch = "bkchr-cumulus-branch" }
+runtime-io = { package = "sr-io", git = "https://github.com/paritytech/substrate", default_features = false, branch = "bkchr-cumulus-branch" }
+version = { package = "sr-version", git = "https://github.com/paritytech/substrate", default_features = false, branch = "bkchr-cumulus-branch" }
+support = { package = "srml-support", git = "https://github.com/paritytech/substrate", default_features = false, branch = "bkchr-cumulus-branch" }
+primitives = { package = "substrate-primitives", git = "https://github.com/paritytech/substrate", default_features = false, branch = "bkchr-cumulus-branch" }
+substrate-session = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "bkchr-cumulus-branch" }
+balances = { package = "srml-balances", git = "https://github.com/paritytech/substrate", default_features = false, branch = "bkchr-cumulus-branch" }
+executive = { package = "srml-executive", git = "https://github.com/paritytech/substrate", default_features = false, branch = "bkchr-cumulus-branch" }
+indices = { package = "srml-indices", git = "https://github.com/paritytech/substrate", default_features = false, branch = "bkchr-cumulus-branch" }
+randomness-collective-flip = { package = "srml-randomness-collective-flip", git = "https://github.com/paritytech/substrate", default_features = false, branch = "bkchr-cumulus-branch" }
+system = { package = "srml-system", git = "https://github.com/paritytech/substrate", default_features = false, branch = "bkchr-cumulus-branch" }
+timestamp = { package = "srml-timestamp", git = "https://github.com/paritytech/substrate", default_features = false, branch = "bkchr-cumulus-branch" }
+sudo = { package = "srml-sudo", git = "https://github.com/paritytech/substrate", default_features = false, branch = "bkchr-cumulus-branch" }
+sr-primitives = { git = "https://github.com/paritytech/substrate", default_features = false, branch = "bkchr-cumulus-branch" }
+client = { package = "substrate-client", git = "https://github.com/paritytech/substrate", default_features = false, branch = "bkchr-cumulus-branch" }
+offchain-primitives = { package = "substrate-offchain-primitives", git = "https://github.com/paritytech/substrate", default-features = false, branch = "bkchr-cumulus-branch" }
+transaction-payment = { package = "srml-transaction-payment", git = "https://github.com/paritytech/substrate", default-features = false, branch = "bkchr-cumulus-branch" }
+
+# Cumulus dependencies
+cumulus-runtime = { path = "../../../runtime", default-features = false }
+
+[build-dependencies]
+wasm-builder-runner = { package = "substrate-wasm-builder-runner", version = "1.0.3" }
+
+[features]
+default = ['std']
+std = [
+	'codec/std',
+	'client/std',
+	'rstd/std',
+	'runtime-io/std',
+	'support/std',
+	'balances/std',
+	'executive/std',
+	'indices/std',
+	'primitives/std',
+	'sr-primitives/std',
+	'randomness-collective-flip/std',
+	'system/std',
+	'timestamp/std',
+	'sudo/std',
+	'version/std',
+	'serde',
+	'safe-mix/std',
+	'offchain-primitives/std',
+	'substrate-session/std',
+	'cumulus-runtime/std',
+	'transaction-payment/std',
+]

cumulus/test/parachain/runtime/build.rs

@@ -0,0 +1,27 @@
+// Copyright 2019 Parity Technologies (UK) Ltd.
+// This file is part of Cumulus.
+
+// Substrate 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.
+
+// Substrate 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 Cumulus.  If not, see <http://www.gnu.org/licenses/>.
+
+use wasm_builder_runner::{build_current_project_with_rustflags, WasmBuilderSource};
+
+fn main() {
+	build_current_project_with_rustflags(
+		"wasm_binary.rs",
+		WasmBuilderSource::Crates("1.0.7"),
+		// This instructs LLD to export __heap_base as a global variable, which is used by the
+		// external memory allocator.
+		"-Clink-arg=--export=__heap_base",
+	);
+}

cumulus/test/parachain/runtime/src/lib.rs

@@ -0,0 +1,336 @@
+// Copyright 2019 Parity Technologies (UK) Ltd.
+// This file is part of Cumulus.
+
+// Cumulus 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.
+
+// Cumulus 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 Cumulus.  If not, see <http://www.gnu.org/licenses/>.
+
+#![cfg_attr(not(feature = "std"), no_std)]
+// `construct_runtime!` does a lot of recursion and requires us to increase the limit to 256.
+#![recursion_limit="256"]
+
+// Make the WASM binary available.
+#[cfg(feature = "std")]
+include!(concat!(env!("OUT_DIR"), "/wasm_binary.rs"));
+
+use rstd::prelude::*;
+use primitives::OpaqueMetadata;
+use sr_primitives::{
+	ApplyResult, transaction_validity::TransactionValidity, generic, create_runtime_str,
+	impl_opaque_keys, AnySignature
+};
+use sr_primitives::traits::{NumberFor, BlakeTwo256, Block as BlockT, StaticLookup, Verify, ConvertInto};
+use sr_primitives::weights::Weight;
+use client::{
+	block_builder::api::{CheckInherentsResult, InherentData, self as block_builder_api},
+	runtime_api as client_api, impl_runtime_apis
+};
+use version::RuntimeVersion;
+#[cfg(feature = "std")]
+use version::NativeVersion;
+
+// A few exports that help ease life for downstream crates.
+#[cfg(any(feature = "std", test))]
+pub use sr_primitives::BuildStorage;
+pub use timestamp::Call as TimestampCall;
+pub use balances::Call as BalancesCall;
+pub use sr_primitives::{Permill, Perbill};
+pub use support::{StorageValue, construct_runtime, parameter_types, traits::Randomness};
+
+/// An index to a block.
+pub type BlockNumber = u32;
+
+/// Alias to 512-bit hash when used in the context of a transaction signature on the chain.
+pub type Signature = AnySignature;
+
+/// Some way of identifying an account on the chain. We intentionally make it equivalent
+/// to the public key of our transaction signing scheme.
+pub type AccountId = <Signature as Verify>::Signer;
+
+/// The type for looking up accounts. We don't expect more than 4 billion of them, but you
+/// never know...
+pub type AccountIndex = u32;
+
+/// Balance of an account.
+pub type Balance = u128;
+
+/// Index of a transaction in the chain.
+pub type Index = u32;
+
+/// A hash of some data used by the chain.
+pub type Hash = primitives::H256;
+
+/// Digest item type.
+pub type DigestItem = generic::DigestItem<Hash>;
+
+/// Opaque types. These are used by the CLI to instantiate machinery that don't need to know
+/// the specifics of the runtime. They can then be made to be agnostic over specific formats
+/// of data like extrinsics, allowing for them to continue syncing the network through upgrades
+/// to even the core datastructures.
+pub mod opaque {
+	use super::*;
+
+	pub use sr_primitives::OpaqueExtrinsic as UncheckedExtrinsic;
+
+	/// Opaque block header type.
+	pub type Header = generic::Header<BlockNumber, BlakeTwo256>;
+	/// Opaque block type.
+	pub type Block = generic::Block<Header, UncheckedExtrinsic>;
+	/// Opaque block identifier type.
+	pub type BlockId = generic::BlockId<Block>;
+
+	pub type SessionHandlers = ();
+
+	impl_opaque_keys! {
+		pub struct SessionKeys {}
+	}
+}
+
+/// This runtime version.
+pub const VERSION: RuntimeVersion = RuntimeVersion {
+	spec_name: create_runtime_str!("wasm-test-parachain"),
+	impl_name: create_runtime_str!("wasm-test-parachain"),
+	authoring_version: 3,
+	spec_version: 4,
+	impl_version: 4,
+	apis: RUNTIME_API_VERSIONS,
+};
+
+pub const MILLISECS_PER_BLOCK: u64 = 6000;
+
+pub const SLOT_DURATION: u64 = MILLISECS_PER_BLOCK;
+
+pub const EPOCH_DURATION_IN_BLOCKS: u32 = 10 * MINUTES;
+
+// These time units are defined in number of blocks.
+pub const MINUTES: BlockNumber = 60_000 / (MILLISECS_PER_BLOCK as BlockNumber);
+pub const HOURS: BlockNumber = MINUTES * 60;
+pub const DAYS: BlockNumber = HOURS * 24;
+
+// 1 in 4 blocks (on average, not counting collisions) will be primary babe blocks.
+pub const PRIMARY_PROBABILITY: (u64, u64) = (1, 4);
+
+/// The version infromation used to identify this runtime when compiled natively.
+#[cfg(feature = "std")]
+pub fn native_version() -> NativeVersion {
+	NativeVersion {
+		runtime_version: VERSION,
+		can_author_with: Default::default(),
+	}
+}
+
+parameter_types! {
+	pub const BlockHashCount: BlockNumber = 250;
+	pub const MaximumBlockWeight: Weight = 1_000_000;
+	pub const AvailableBlockRatio: Perbill = Perbill::from_percent(75);
+	pub const MaximumBlockLength: u32 = 5 * 1024 * 1024;
+	pub const Version: RuntimeVersion = VERSION;
+}
+
+impl system::Trait for Runtime {
+	/// The identifier used to distinguish between accounts.
+	type AccountId = AccountId;
+	/// The aggregated dispatch type that is available for extrinsics.
+	type Call = Call;
+	/// The lookup mechanism to get account ID from whatever is passed in dispatchers.
+	type Lookup = Indices;
+	/// The index type for storing how many extrinsics an account has signed.
+	type Index = Index;
+	/// The index type for blocks.
+	type BlockNumber = BlockNumber;
+	/// The type for hashing blocks and tries.
+	type Hash = Hash;
+	/// The hashing algorithm used.
+	type Hashing = BlakeTwo256;
+	/// The header type.
+	type Header = generic::Header<BlockNumber, BlakeTwo256>;
+	/// The ubiquitous event type.
+	type Event = Event;
+	/// The ubiquitous origin type.
+	type Origin = Origin;
+	/// Maximum number of block number to block hash mappings to keep (oldest pruned first).
+	type BlockHashCount = BlockHashCount;
+	/// Maximum weight of each block. With a default weight system of 1byte == 1weight, 4mb is ok.
+	type MaximumBlockWeight = MaximumBlockWeight;
+	/// Maximum size of all encoded transactions (in bytes) that are allowed in one block.
+	type MaximumBlockLength = MaximumBlockLength;
+	/// Portion of the block weight that is available to all normal transactions.
+	type AvailableBlockRatio = AvailableBlockRatio;
+	type Version = Version;
+}
+
+impl indices::Trait for Runtime {
+	/// The type for recording indexing into the account enumeration. If this ever overflows, there
+	/// will be problems!
+	type AccountIndex = u32;
+	/// Use the standard means of resolving an index hint from an id.
+	type ResolveHint = indices::SimpleResolveHint<Self::AccountId, Self::AccountIndex>;
+	/// Determine whether an account is dead.
+	type IsDeadAccount = Balances;
+	/// The ubiquitous event type.
+	type Event = Event;
+}
+
+parameter_types! {
+	pub const MinimumPeriod: u64 = SLOT_DURATION / 2;
+}
+
+impl timestamp::Trait for Runtime {
+	/// A timestamp: milliseconds since the unix epoch.
+	type Moment = u64;
+	type OnTimestampSet = ();
+	type MinimumPeriod = MinimumPeriod;
+}
+
+parameter_types! {
+	pub const ExistentialDeposit: u128 = 500;
+	pub const TransferFee: u128 = 0;
+	pub const CreationFee: u128 = 0;
+	pub const TransactionBaseFee: u128 = 0;
+	pub const TransactionByteFee: u128 = 1;
+}
+
+impl balances::Trait for Runtime {
+	/// The type for recording an account's balance.
+	type Balance = Balance;
+	/// What to do if an account's free balance gets zeroed.
+	type OnFreeBalanceZero = ();
+	/// What to do if a new account is created.
+	type OnNewAccount = Indices;
+	/// The ubiquitous event type.
+	type Event = Event;
+	type DustRemoval = ();
+	type TransferPayment = ();
+	type ExistentialDeposit = ExistentialDeposit;
+	type TransferFee = TransferFee;
+	type CreationFee = CreationFee;
+}
+
+impl transaction_payment::Trait for Runtime {
+	type Currency = Balances;
+	type OnTransactionPayment = ();
+	type TransactionBaseFee = TransactionBaseFee;
+	type TransactionByteFee = TransactionByteFee;
+	type WeightToFee = ConvertInto;
+	type FeeMultiplierUpdate = ();
+}
+
+impl sudo::Trait for Runtime {
+	type Event = Event;
+	type Proposal = Call;
+}
+
+construct_runtime! {
+	pub enum Runtime where
+		Block = Block,
+		NodeBlock = opaque::Block,
+		UncheckedExtrinsic = UncheckedExtrinsic
+	{
+		System: system::{Module, Call, Storage, Config, Event},
+		Timestamp: timestamp::{Module, Call, Storage, Inherent},
+		Indices: indices::{default, Config<T>},
+		Balances: balances::{default, Error},
+		Sudo: sudo,
+		RandomnessCollectiveFlip: randomness_collective_flip::{Module, Call, Storage},
+	}
+}
+
+/// The address format for describing accounts.
+pub type Address = <Indices as StaticLookup>::Source;
+/// Block header type as expected by this runtime.
+pub type Header = generic::Header<BlockNumber, BlakeTwo256>;
+/// Block type as expected by this runtime.
+pub type Block = generic::Block<Header, UncheckedExtrinsic>;
+/// A Block signed with a Justification
+pub type SignedBlock = generic::SignedBlock<Block>;
+/// BlockId type as expected by this runtime.
+pub type BlockId = generic::BlockId<Block>;
+/// The SignedExtension to the basic transaction logic.
+pub type SignedExtra = (
+	system::CheckVersion<Runtime>,
+	system::CheckGenesis<Runtime>,
+	system::CheckEra<Runtime>,
+	system::CheckNonce<Runtime>,
+	system::CheckWeight<Runtime>,
+	transaction_payment::ChargeTransactionPayment<Runtime>,
+);
+/// Unchecked extrinsic type as expected by this runtime.
+pub type UncheckedExtrinsic = generic::UncheckedExtrinsic<Address, Call, Signature, SignedExtra>;
+/// Extrinsic type that has already been checked.
+pub type CheckedExtrinsic = generic::CheckedExtrinsic<AccountId, Call, SignedExtra>;
+/// Executive: handles dispatch to the various modules.
+pub type Executive = executive::Executive<Runtime, Block, system::ChainContext<Runtime>, Runtime, AllModules>;
+
+impl_runtime_apis! {
+	impl client_api::Core<Block> for Runtime {
+		fn version() -> RuntimeVersion {
+			VERSION
+		}
+
+		fn execute_block(block: Block) {
+			Executive::execute_block(block)
+		}
+
+		fn initialize_block(header: &<Block as BlockT>::Header) {
+			Executive::initialize_block(header)
+		}
+	}
+
+	impl client_api::Metadata<Block> for Runtime {
+		fn metadata() -> OpaqueMetadata {
+			Runtime::metadata().into()
+		}
+	}
+
+	impl block_builder_api::BlockBuilder<Block> for Runtime {
+		fn apply_extrinsic(extrinsic: <Block as BlockT>::Extrinsic) -> ApplyResult {
+			Executive::apply_extrinsic(extrinsic)
+		}
+
+		fn finalize_block() -> <Block as BlockT>::Header {
+			Executive::finalize_block()
+		}
+
+		fn inherent_extrinsics(data: InherentData) -> Vec<<Block as BlockT>::Extrinsic> {
+			data.create_extrinsics()
+		}
+
+		fn check_inherents(block: Block, data: InherentData) -> CheckInherentsResult {
+			data.check_extrinsics(&block)
+		}
+
+		fn random_seed() -> <Block as BlockT>::Hash {
+			RandomnessCollectiveFlip::random_seed()
+		}
+	}
+
+	impl client_api::TaggedTransactionQueue<Block> for Runtime {
+		fn validate_transaction(tx: <Block as BlockT>::Extrinsic) -> TransactionValidity {
+			Executive::validate_transaction(tx)
+		}
+	}
+
+	impl offchain_primitives::OffchainWorkerApi<Block> for Runtime {
+		fn offchain_worker(number: NumberFor<Block>) {
+			Executive::offchain_worker(number)
+		}
+	}
+
+	impl substrate_session::SessionKeys<Block> for Runtime {
+		fn generate_session_keys(seed: Option<Vec<u8>>) -> Vec<u8> {
+			let seed = seed.as_ref().map(|s| rstd::str::from_utf8(&s).expect("Seed is an utf8 string"));
+			opaque::SessionKeys::generate(seed)
+		}
+	}
+}
+
+cumulus_runtime::register_validate_block!(Block, Executive);

cumulus/test/parachain/src/chain_spec.rs

@@ -0,0 +1,95 @@
+// Copyright 2019 Parity Technologies (UK) Ltd.
+// This file is part of Cumulus.
+
+// Cumulus 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.
+
+// Cumulus 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 Cumulus.  If not, see <http://www.gnu.org/licenses/>.
+
+use substrate_primitives::{Pair, Public};
+use parachain_runtime::{
+	AccountId, BalancesConfig, GenesisConfig, SudoConfig, IndicesConfig, SystemConfig, WASM_BINARY,
+};
+use substrate_service;
+
+/// Specialized `ChainSpec`. This is a specialization of the general Substrate ChainSpec type.
+pub type ChainSpec = substrate_service::ChainSpec<GenesisConfig>;
+
+/// Helper function to generate a crypto pair from seed
+pub fn get_from_seed<TPublic: Public>(seed: &str) -> <TPublic::Pair as Pair>::Public {
+	TPublic::Pair::from_string(&format!("//{}", seed), None)
+		.expect("static values are valid; qed")
+		.public()
+}
+
+/// Helper function to generate stash, controller and session key from seed
+pub fn get_authority_keys_from_seed(seed: &str) -> (AccountId, AccountId) {
+	(get_from_seed::<AccountId>(&format!("{}//stash", seed)), get_from_seed::<AccountId>(seed))
+}
+
+/// Returns the chain spec.
+pub fn get_chain_spec() -> ChainSpec {
+	ChainSpec::from_genesis(
+		"Local Testnet",
+		"parachain_local_testnet",
+		|| testnet_genesis(
+			vec![
+				get_authority_keys_from_seed("Alice"),
+				get_authority_keys_from_seed("Bob"),
+			],
+			get_from_seed::<AccountId>("Alice"),
+			vec![
+				get_from_seed::<AccountId>("Alice"),
+				get_from_seed::<AccountId>("Bob"),
+				get_from_seed::<AccountId>("Charlie"),
+				get_from_seed::<AccountId>("Dave"),
+				get_from_seed::<AccountId>("Eve"),
+				get_from_seed::<AccountId>("Ferdie"),
+				get_from_seed::<AccountId>("Alice//stash"),
+				get_from_seed::<AccountId>("Bob//stash"),
+				get_from_seed::<AccountId>("Charlie//stash"),
+				get_from_seed::<AccountId>("Dave//stash"),
+				get_from_seed::<AccountId>("Eve//stash"),
+				get_from_seed::<AccountId>("Ferdie//stash"),
+			],
+			true,
+		),
+		vec![],
+		None,
+		None,
+		None,
+		None,
+	)
+}
+
+fn testnet_genesis(
+	_initial_authorities: Vec<(AccountId, AccountId)>,
+	root_key: AccountId,
+	endowed_accounts: Vec<AccountId>,
+	_enable_println: bool,
+) -> GenesisConfig {
+	GenesisConfig {
+		system: Some(SystemConfig {
+			code: WASM_BINARY.to_vec(),
+			changes_trie_config: Default::default(),
+		}),
+		indices: Some(IndicesConfig {
+			ids: endowed_accounts.clone(),
+		}),
+		balances: Some(BalancesConfig {
+			balances: endowed_accounts.iter().cloned().map(|k|(k, 1 << 60)).collect(),
+			vesting: vec![],
+		}),
+		sudo: Some(SudoConfig {
+			key: root_key,
+		}),
+	}
+}

cumulus/test/parachain/src/cli.rs

@@ -0,0 +1,158 @@
+// Copyright 2019 Parity Technologies (UK) Ltd.
+// This file is part of Cumulus.
+
+// Cumulus 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.
+
+// Cumulus 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 Cumulus.  If not, see <http://www.gnu.org/licenses/>.
+
+use crate::chain_spec;
+
+use parachain_runtime::Block;
+
+pub use substrate_cli::{VersionInfo, IntoExit, error::{self, Result}};
+use substrate_cli::{parse_and_prepare, ParseAndPrepare, NoCustom};
+use substrate_service::{Roles as ServiceRoles, Configuration};
+use sr_primitives::{traits::{Block as BlockT, Header as HeaderT, Hash as HashT}, BuildStorage};
+use substrate_client::genesis;
+use substrate_primitives::hexdisplay::HexDisplay;
+
+use codec::Encode;
+
+use log::info;
+
+use std::{path::PathBuf, cell::RefCell, sync::Arc};
+
+use structopt::StructOpt;
+
+use futures::{sync::oneshot, future, Future};
+
+/// Sub-commands supported by the collator.
+#[derive(Debug, StructOpt, Clone)]
+enum SubCommands {
+	/// Export the genesis state of the parachain.
+	#[structopt(name = "export-genesis-state")]
+	ExportGenesisState(ExportGenesisStateCommand),
+}
+
+impl substrate_cli::GetLogFilter for SubCommands {
+	fn get_log_filter(&self) -> Option<String> { None }
+}
+
+/// Command for exporting the genesis state of the parachain
+#[derive(Debug, StructOpt, Clone)]
+struct ExportGenesisStateCommand {
+	/// Output file name or stdout if unspecified.
+	#[structopt(parse(from_os_str))]
+	pub output: Option<PathBuf>,
+}
+
+/// Parse command line arguments into service configuration.
+pub fn run<I, T, E>(args: I, exit: E, version: VersionInfo) -> error::Result<()>
+	where
+		I: IntoIterator<Item = T>,
+		T: Into<std::ffi::OsString> + Clone,
+		E: IntoExit + Send + 'static,
+{
+	type Config<T> = Configuration<(), T>;
+	match parse_and_prepare::<SubCommands, NoCustom, _>(
+		&version,
+		"cumulus-test-parachain-collator",
+		args,
+	) {
+		ParseAndPrepare::Run(cmd) => cmd.run(load_spec, exit,
+		|exit, _cli_args, _custom_args, mut config: Config<_>| {
+			info!("{}", version.name);
+			info!("  version {}", config.full_version());
+			info!("  by {}, 2019", version.author);
+			info!("Chain specification: {}", config.chain_spec.name());
+			info!("Node name: {}", config.name);
+			info!("Roles: {:?}", config.roles);
+			info!("Parachain id: {:?}", crate::PARA_ID);
+
+			// TODO
+			let key = Arc::new(substrate_primitives::Pair::from_seed(&[10; 32]));
+
+			// TODO
+			config.network.listen_addresses = Vec::new();
+			config.network.boot_nodes = vec![];
+			config.chain_spec = chain_spec::get_chain_spec();
+
+			match config.roles {
+				ServiceRoles::LIGHT => unimplemented!("Light client not supported!"),
+				_ => crate::service::run_collator(config, exit, key, version.clone()),
+			}.map_err(|e| format!("{:?}", e))
+		}),
+		ParseAndPrepare::BuildSpec(cmd) => cmd.run(load_spec),
+		ParseAndPrepare::ExportBlocks(cmd) => cmd.run_with_builder(|config: Config<_>|
+			Ok(new_full_start!(config).0), load_spec, exit),
+		ParseAndPrepare::ImportBlocks(cmd) => cmd.run_with_builder(|config: Config<_>|
+			Ok(new_full_start!(config).0), load_spec, exit),
+		ParseAndPrepare::PurgeChain(cmd) => cmd.run(load_spec),
+		ParseAndPrepare::RevertChain(cmd) => cmd.run_with_builder(|config: Config<_>|
+			Ok(new_full_start!(config).0), load_spec),
+		ParseAndPrepare::CustomCommand(SubCommands::ExportGenesisState(cmd)) => {
+			export_genesis_state(cmd.output)
+		}
+	}?;
+
+	Ok(())
+}
+
+fn load_spec(_: &str) -> std::result::Result<Option<chain_spec::ChainSpec>, String> {
+	Ok(Some(chain_spec::get_chain_spec()))
+}
+
+/// Export the genesis state of the parachain.
+fn export_genesis_state(output: Option<PathBuf>) -> error::Result<()> {
+	let storage = chain_spec::get_chain_spec().build_storage()?;
+
+	let child_roots = storage.1.iter().map(|(sk, child_map)| {
+		let state_root = <<<Block as BlockT>::Header as HeaderT>::Hashing as HashT>::trie_root(
+			child_map.clone().into_iter().collect()
+		);
+		(sk.clone(), state_root.encode())
+	});
+	let state_root = <<<Block as BlockT>::Header as HeaderT>::Hashing as HashT>::trie_root(
+		storage.0.clone().into_iter().chain(child_roots).collect()
+	);
+	let block: Block = genesis::construct_genesis_block(state_root);
+
+	let header_hex = format!("0x{:?}", HexDisplay::from(&block.header().encode()));
+
+	if let Some(output) = output {
+		std::fs::write(output, header_hex)?;
+	} else {
+		println!("{}", header_hex);
+	}
+
+	Ok(())
+}
+
+// handles ctrl-c
+pub struct Exit;
+impl IntoExit for Exit {
+	type Exit = future::MapErr<oneshot::Receiver<()>, fn(oneshot::Canceled) -> ()>;
+	fn into_exit(self) -> Self::Exit {
+		// can't use signal directly here because CtrlC takes only `Fn`.
+		let (exit_send, exit) = oneshot::channel();
+
+		let exit_send_cell = RefCell::new(Some(exit_send));
+		ctrlc::set_handler(move || {
+			let exit_send = exit_send_cell.try_borrow_mut().expect("signal handler not reentrant; qed").take();
+			if let Some(exit_send) = exit_send {
+				exit_send.send(()).expect("Error sending exit notification");
+			}
+		}).expect("Error setting Ctrl-C handler");
+
+		exit.map_err(drop)
+	}
+}

cumulus/test/parachain/src/main.rs

@@ -0,0 +1,46 @@
+// Copyright 2019 Parity Technologies (UK) Ltd.
+// This file is part of Cumulus.
+
+// Cumulus 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.
+
+// Cumulus 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 Cumulus.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Cumulus test parachain collator
+
+#![warn(missing_docs)]
+#![warn(unused_extern_crates)]
+
+use polkadot_primitives::parachain::Id as ParaId;
+
+mod chain_spec;
+#[macro_use]
+mod service;
+mod cli;
+
+pub use substrate_cli::{VersionInfo, IntoExit, error};
+
+/// The parachain id of this parachain.
+pub const PARA_ID: ParaId = ParaId::new(100);
+
+fn main() -> Result<(), cli::error::Error> {
+	let version = VersionInfo {
+		name: "Cumulus Test Parachain Collator",
+		commit: env!("VERGEN_SHA_SHORT"),
+		version: env!("CARGO_PKG_VERSION"),
+		executable_name: "cumulus-test-parachain-collator",
+		author: "Parity Technologies <admin@parity.io>",
+		description: "Cumulus test parachain collator",
+		support_url: "https://github.com/paritytech/cumulus/issues/new",
+	};
+
+	cli::run(std::env::args(), cli::Exit, version)
+}

cumulus/test/parachain/src/service.rs

@@ -0,0 +1,154 @@
+// Copyright 2019 Parity Technologies (UK) Ltd.
+// This file is part of Cumulus.
+
+// Cumulus 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.
+
+// Cumulus 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 Cumulus.  If not, see <http://www.gnu.org/licenses/>.
+
+use std::sync::Arc;
+
+use parachain_runtime::{self, GenesisConfig, opaque::Block};
+
+use inherents::InherentDataProviders;
+use substrate_service::{AbstractService, Configuration};
+use network::construct_simple_protocol;
+use substrate_executor::native_executor_instance;
+
+use futures::prelude::*;
+
+use futures03::FutureExt;
+
+use log::error;
+
+pub use substrate_executor::NativeExecutor;
+
+// Our native executor instance.
+native_executor_instance!(
+	pub Executor,
+	parachain_runtime::api::dispatch,
+	parachain_runtime::native_version,
+);
+
+construct_simple_protocol! {
+	/// Demo protocol attachment for substrate.
+	pub struct NodeProtocol where Block = Block { }
+}
+
+/// Starts a `ServiceBuilder` for a full service.
+///
+/// Use this macro if you don't actually need the full service, but just the builder in order to
+/// be able to perform chain operations.
+macro_rules! new_full_start {
+	($config:expr) => {{
+		let inherent_data_providers = inherents::InherentDataProviders::new();
+
+		let builder = substrate_service::ServiceBuilder::new_full::<
+			parachain_runtime::opaque::Block, parachain_runtime::RuntimeApi, crate::service::Executor,
+		>($config)?
+			.with_select_chain(|_config, backend| {
+				Ok(substrate_client::LongestChain::new(backend.clone()))
+			})?
+			.with_transaction_pool(|config, client|
+				Ok(transaction_pool::txpool::Pool::new(config, transaction_pool::FullChainApi::new(client)))
+			)?
+			.with_import_queue(|_config, client, _, _| {
+				let import_queue = cumulus_consensus::import_queue::import_queue(
+					client.clone(),
+					client,
+					inherent_data_providers.clone(),
+				)?;
+
+				Ok(import_queue)
+			})?;
+
+		(builder, inherent_data_providers)
+	}}
+}
+
+/// Run the collator with the given `config`.
+pub fn run_collator<C: Send + Default + 'static, E: crate::cli::IntoExit + Send + 'static>(
+	config: Configuration<C, GenesisConfig>,
+	exit: E,
+	key: Arc<polkadot_primitives::parachain::CollatorPair>,
+	version: crate::cli::VersionInfo,
+) -> crate::cli::Result<()> {
+	let (builder, inherent_data_providers) = new_full_start!(config);
+	inherent_data_providers.register_provider(srml_timestamp::InherentDataProvider).unwrap();
+
+	let service = builder.with_network_protocol(|_| Ok(NodeProtocol::new()))?.build()?;
+	let proposer_factory = basic_authorship::ProposerFactory {
+		client: service.client(),
+		transaction_pool: service.transaction_pool(),
+	};
+
+	let on_exit = service.on_exit();
+	let block_import = service.client();
+
+	let setup_parachain = SetupParachain {
+		service,
+		inherent_data_providers,
+		proposer_factory,
+		exit,
+		block_import,
+	};
+
+	cumulus_collator::run_collator(setup_parachain, crate::PARA_ID, on_exit, key, version)
+}
+
+struct SetupParachain<S, PF, E, BI> {
+	service: S,
+	proposer_factory: PF,
+	exit: E,
+	inherent_data_providers: InherentDataProviders,
+	block_import: BI,
+}
+
+impl<S, PF, E, BI> cumulus_collator::SetupParachain<Block> for SetupParachain<S, PF, E, BI>
+	where
+		S: AbstractService,
+		E: Send + crate::cli::IntoExit,
+		PF: consensus_common::Environment<Block> + Send + 'static,
+		BI: consensus_common::BlockImport<Block, Error=consensus_common::Error> + Send + Sync + 'static,
+{
+	type ProposerFactory = PF;
+	type BlockImport = BI;
+
+	fn setup_parachain<P: cumulus_consensus::PolkadotClient>(
+		self,
+		polkadot_client: P,
+		task_executor: polkadot_collator::TaskExecutor,
+	) -> Result<(Self::ProposerFactory, Self::BlockImport, InherentDataProviders), String> {
+		let client = self.service.client();
+
+		let follow = match cumulus_consensus::follow_polkadot(crate::PARA_ID, client, polkadot_client) {
+			Ok(follow) => follow,
+			Err(e) => {
+				return Err(format!("Could not start following polkadot: {:?}", e));
+			}
+		};
+
+		task_executor.execute(
+			Box::new(
+				self.service
+					.map_err(|e| error!("Parachain service error: {:?}", e))
+					.select(futures03::compat::Compat::new(follow.map(|_| Ok::<(), ()>(()))))
+					.map(|_| ())
+					.map_err(|_| ())
+					.select(self.exit.into_exit())
+					.map(|_| ())
+					.map_err(|_| ())
+			),
+		).map_err(|_| "Could not spawn parachain server!")?;
+
+		Ok((self.proposer_factory, self.block_import, self.inherent_data_providers))
+	}
+}