lib.rs 18.5 KB
Newer Older
Shawn Tabrizi's avatar
Shawn Tabrizi committed
1
// Copyright 2017-2020 Parity Technologies (UK) Ltd.
Gav's avatar
Gav committed
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
// This file is part of Polkadot.

// Polkadot 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.

// Polkadot 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 Polkadot.  If not, see <http://www.gnu.org/licenses/>.

17
//! Collation node logic.
Gav's avatar
Gav committed
18
19
20
21
22
23
24
25
26
27
28
29
30
//!
//! A collator node lives on a distinct parachain and submits a proposal for
//! a state transition, along with a proof for its validity
//! (what we might call a witness or block data).
//!
//! One of collators' other roles is to route messages between chains.
//! Each parachain produces a list of "egress" posts of messages for each other
//! parachain on each block, for a total of N^2 lists all together.
//!
//! We will refer to the egress list at relay chain block X of parachain A with
//! destination B as egress(X)[A -> B]
//!
//! On every block, each parachain will be intended to route messages from some
31
//! subset of all the other parachains. (NOTE: in practice this is not done until PoC-3)
Gav's avatar
Gav committed
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
//!
//! Since the egress information is unique to every block, when routing from a
//! parachain a collator must gather all egress posts from that parachain
//! up to the last point in history that messages were successfully routed
//! from that parachain, accounting for relay chain blocks where no candidate
//! from the collator's parachain was produced.
//!
//! In the case that all parachains route to each other and a candidate for the
//! collator's parachain was included in the last relay chain block, the collator
//! only has to gather egress posts from other parachains one block back in relay
//! chain history.
//!
//! This crate defines traits which provide context necessary for collation logic
//! to be performed, as the collation logic itself.

47
use std::collections::HashSet;
48
use std::fmt;
49
use std::sync::Arc;
50
use std::time::Duration;
51
use std::pin::Pin;
Gav's avatar
Gav committed
52

53
use futures::{future, Future, Stream, FutureExt, TryFutureExt, StreamExt, task::Spawn};
54
use log::warn;
55
56
use sc_client::BlockchainEvents;
use sp_core::{Pair, Blake2Hasher};
57
use polkadot_primitives::{
58
	BlockId, Hash, Block,
59
	parachain::{
60
61
		self, BlockData, DutyRoster, HeadData, ConsolidatedIngress, Message, Id as ParaId,
		OutgoingMessages, PoVBlock, Status as ParachainStatus, ValidatorId, CollatorPair,
62
63
64
	}
};
use polkadot_cli::{
65
	ProvideRuntimeApi, AbstractService, ParachainHost, IsKusama,
66
	service::{self, Roles, SelectChain}
67
};
68
use polkadot_network::validation::{LeafWorkParams, ValidationNetwork};
69

70
pub use polkadot_cli::{VersionInfo, load_spec, service::Configuration};
71
pub use polkadot_network::validation::Incoming;
72
73
pub use polkadot_validation::SignedStatement;
pub use polkadot_primitives::parachain::CollatorId;
74
pub use sc_network::PeerId;
75
pub use service::RuntimeApiCollection;
76

77
const COLLATION_TIMEOUT: Duration = Duration::from_secs(30);
Gav's avatar
Gav committed
78

79
/// An abstraction over the `Network` with useful functions for a `Collator`.
80
pub trait Network: Send + Sync {
81
82
	/// Convert the given `CollatorId` to a `PeerId`.
	fn collator_id_to_peer_id(&self, collator_id: CollatorId) ->
83
		Box<dyn Future<Output=Option<PeerId>> + Send>;
84
85
86
87
88
89

	/// Create a `Stream` of checked statements for the given `relay_parent`.
	///
	/// The returned stream will not terminate, so it is required to make sure that the stream is
	/// dropped when it is not required anymore. Otherwise, it will stick around in memory
	/// infinitely.
90
	fn checked_statements(&self, relay_parent: Hash) -> Box<dyn Stream<Item=SignedStatement>>;
91
92
}

Gavin Wood's avatar
Gavin Wood committed
93
impl<P, SP> Network for ValidationNetwork<P, SP> where
94
	P: 'static + Send + Sync,
95
	SP: 'static + Spawn + Clone + Send + Sync,
96
97
{
	fn collator_id_to_peer_id(&self, collator_id: CollatorId) ->
98
		Box<dyn Future<Output=Option<PeerId>> + Send>
99
	{
100
		Box::new(Self::collator_id_to_peer_id(self, collator_id))
101
102
	}

103
	fn checked_statements(&self, relay_parent: Hash) -> Box<dyn Stream<Item=SignedStatement>> {
104
		Box::new(Self::checked_statements(self, relay_parent))
105
106
107
	}
}

108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
/// Error to return when the head data was invalid.
#[derive(Clone, Copy, Debug)]
pub struct InvalidHead;

/// Collation errors.
#[derive(Debug)]
pub enum Error<R> {
	/// Error on the relay-chain side of things.
	Polkadot(R),
	/// Error on the collator side of things.
	Collator(InvalidHead),
}

impl<R: fmt::Display> fmt::Display for Error<R> {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
		match *self {
			Error::Polkadot(ref err) => write!(f, "Polkadot node error: {}", err),
			Error::Collator(_) => write!(f, "Collator node error: Invalid head data"),
		}
	}
}

130
/// The Polkadot client type.
131
pub type PolkadotClient<B, E, R> = sc_client::Client<B, E, Block, R>;
132

133
134
135
136
137
138
/// Something that can build a `ParachainContext`.
pub trait BuildParachainContext {
	/// The parachain context produced by the `build` function.
	type ParachainContext: self::ParachainContext;

	/// Build the `ParachainContext`.
139
	fn build<B, E, R, SP, Extrinsic>(
140
		self,
141
		client: Arc<PolkadotClient<B, E, R>>,
142
		spawner: SP,
143
144
145
		network: Arc<dyn Network>,
	) -> Result<Self::ParachainContext, ()>
		where
146
			PolkadotClient<B, E, R>: ProvideRuntimeApi<Block>,
147
			<PolkadotClient<B, E, R> as ProvideRuntimeApi<Block>>::Api: RuntimeApiCollection<Extrinsic>,
148
149
150
151
152
			// Rust bug: https://github.com/rust-lang/rust/issues/24159
			<<PolkadotClient<B, E, R> as ProvideRuntimeApi<Block>>::Api as sp_api::ApiExt<Block>>::StateBackend:
				sp_api::StateBackend<Blake2Hasher>,
			Extrinsic: codec::Codec + Send + Sync + 'static,
			E: sc_client::CallExecutor<Block> + Clone + Send + Sync + 'static,
153
154
155
156
157
			SP: Spawn + Clone + Send + Sync + 'static,
			R: Send + Sync + 'static,
			B: sc_client_api::Backend<Block> + 'static,
			// Rust bug: https://github.com/rust-lang/rust/issues/24159
			B::State: sp_api::StateBackend<Blake2Hasher>;
158
159
}

Gav's avatar
Gav committed
160
161
162
/// Parachain context needed for collation.
///
/// This can be implemented through an externally attached service or a stub.
163
164
/// This is expected to be a lightweight, shared type like an Arc.
pub trait ParachainContext: Clone {
165
	type ProduceCandidate: Future<Output = Result<(BlockData, HeadData, OutgoingMessages), InvalidHead>>;
166

167
168
	/// Produce a candidate, given the relay parent hash, the latest ingress queue information
	/// and the last parachain head.
Gav's avatar
Gav committed
169
	fn produce_candidate<I: IntoIterator<Item=(ParaId, Message)>>(
170
		&mut self,
171
		relay_parent: Hash,
172
		status: ParachainStatus,
Gav's avatar
Gav committed
173
		ingress: I,
174
	) -> Self::ProduceCandidate;
Gav's avatar
Gav committed
175
176
177
178
179
180
}

/// Relay chain context needed to collate.
/// This encapsulates a network and local database which may store
/// some of the input.
pub trait RelayChainContext {
181
	type Error: std::fmt::Debug;
Gav's avatar
Gav committed
182
183
184

	/// Future that resolves to the un-routed egress queues of a parachain.
	/// The first item is the oldest.
185
	type FutureEgress: Future<Output = Result<ConsolidatedIngress, Self::Error>>;
Gav's avatar
Gav committed
186
187

	/// Get un-routed egress queues from a parachain to the local parachain.
188
	fn unrouted_egress(&self, _id: ParaId) -> Self::FutureEgress;
Gav's avatar
Gav committed
189
190
}

191
/// Produce a candidate for the parachain, with given contexts, parent head, and signing key.
192
pub async fn collate<R, P>(
193
	relay_parent: Hash,
194
	local_id: ParaId,
195
	parachain_status: ParachainStatus,
196
	relay_context: R,
197
	mut para_context: P,
198
	key: Arc<CollatorPair>,
199
)
200
	-> Result<(parachain::Collation, OutgoingMessages), Error<R::Error>>
Gav's avatar
Gav committed
201
	where
202
		R: RelayChainContext,
203
204
		P: ParachainContext,
		P::ProduceCandidate: Send,
Gav's avatar
Gav committed
205
{
206
207
208
209
210
211
212
213
214
215
216
217
218
	let ingress = relay_context.unrouted_egress(local_id).await.map_err(Error::Polkadot)?;

	let (block_data, head_data, mut outgoing) = para_context.produce_candidate(
		relay_parent,
		parachain_status,
		ingress.0.iter().flat_map(|&(id, ref msgs)| msgs.iter().cloned().map(move |msg| (id, msg)))
	).map_err(Error::Collator).await?;

	let block_data_hash = block_data.hash();
	let signature = key.sign(block_data_hash.as_ref());
	let egress_queue_roots =
		polkadot_validation::egress_roots(&mut outgoing.outgoing_messages);

219
	let info = parachain::CollationInfo {
220
221
222
223
		parachain_index: local_id,
		collator: key.public(),
		signature,
		egress_queue_roots,
224
		head_data,
225
226
227
228
229
		block_data_hash,
		upward_messages: Vec::new(),
	};

	let collation = parachain::Collation {
230
		info,
231
232
233
234
235
236
237
		pov: PoVBlock {
			block_data,
			ingress,
		},
	};

	Ok((collation, outgoing))
Gav's avatar
Gav committed
238
239
}

240
/// Polkadot-api context.
Gavin Wood's avatar
Gavin Wood committed
241
242
struct ApiContext<P, SP> {
	network: Arc<ValidationNetwork<P, SP>>,
243
	parent_hash: Hash,
244
	validators: Vec<ValidatorId>,
245
}
246

Gavin Wood's avatar
Gavin Wood committed
247
impl<P: 'static, SP: 'static> RelayChainContext for ApiContext<P, SP> where
248
	P: ProvideRuntimeApi<Block> + Send + Sync,
249
	P::Api: ParachainHost<Block>,
250
	SP: Spawn + Clone + Send + Sync
251
252
{
	type Error = String;
253
	type FutureEgress = Pin<Box<dyn Future<Output=Result<ConsolidatedIngress, String>> + Send>>;
254

255
	fn unrouted_egress(&self, _id: ParaId) -> Self::FutureEgress {
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
		let network = self.network.clone();
		let parent_hash = self.parent_hash;
		let authorities = self.validators.clone();

		async move {
			// TODO: https://github.com/paritytech/polkadot/issues/253
			//
			// Fetch ingress and accumulate all unrounted egress
			let _session = network.instantiate_leaf_work(LeafWorkParams {
				local_session_key: None,
				parent_hash,
				authorities,
			})
				.map_err(|e| format!("unable to instantiate validation session: {:?}", e));

			Ok(ConsolidatedIngress(Vec::new()))
		}.boxed()
273
274
275
	}
}

276
/// Run the collator node using the given `service`.
Gavin Wood's avatar
Gavin Wood committed
277
fn run_collator_node<S, P, Extrinsic>(
278
	service: S,
279
	para_id: ParaId,
280
	key: Arc<CollatorPair>,
281
	build_parachain_context: P,
Gavin Wood's avatar
Gavin Wood committed
282
) -> Result<S, polkadot_service::Error>
283
284
	where
		S: AbstractService<Block = service::Block, NetworkSpecialization = service::PolkadotProtocol>,
285
286
		sc_client::Client<S::Backend, S::CallExecutor, service::Block, S::RuntimeApi>: ProvideRuntimeApi<Block>,
		<sc_client::Client<S::Backend, S::CallExecutor, service::Block, S::RuntimeApi> as ProvideRuntimeApi<Block>>::Api:
287
			RuntimeApiCollection<
288
289
290
291
				Extrinsic,
				Error = sp_blockchain::Error,
				StateBackend = sc_client_api::StateBackendFor<S::Backend, Block>
			>,
292
		// Rust bug: https://github.com/rust-lang/rust/issues/24159
293
		S::Backend: service::Backend<service::Block>,
294
		// Rust bug: https://github.com/rust-lang/rust/issues/24159
295
296
297
298
		<S::Backend as service::Backend<service::Block>>::State:
			sp_api::StateBackend<sp_runtime::traits::HasherFor<Block>>,
		// Rust bug: https://github.com/rust-lang/rust/issues/24159
		S::CallExecutor: service::CallExecutor<service::Block>,
299
300
301
302
303
		// Rust bug: https://github.com/rust-lang/rust/issues/24159
		S::SelectChain: service::SelectChain<service::Block>,
		P: BuildParachainContext,
		P::ParachainContext: Send + 'static,
		<P::ParachainContext as ParachainContext>::ProduceCandidate: Send,
304
		Extrinsic: service::Codec + Send + Sync + 'static,
305
{
306
	let spawner = service.spawn_task_handle();
307
308
309
310
311
312
313

	let client = service.client();
	let network = service.network();
	let known_oracle = client.clone();
	let select_chain = if let Some(select_chain) = service.select_chain() {
		select_chain
	} else {
Gavin Wood's avatar
Gavin Wood committed
314
		return Err("The node cannot work because it can't select chain.".into())
315
	};
316

317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
	let is_known = move |block_hash: &Hash| {
		use consensus_common::BlockStatus;
		use polkadot_network::gossip::Known;

		match known_oracle.block_status(&BlockId::hash(*block_hash)) {
			Err(_) | Ok(BlockStatus::Unknown) | Ok(BlockStatus::Queued) => None,
			Ok(BlockStatus::KnownBad) => Some(Known::Bad),
			Ok(BlockStatus::InChainWithState) | Ok(BlockStatus::InChainPruned) =>
				match select_chain.leaves() {
					Err(_) => None,
					Ok(leaves) => if leaves.contains(block_hash) {
						Some(Known::Leaf)
					} else {
						Some(Known::Old)
					},
				}
		}
	};
335

336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
	let message_validator = polkadot_network::gossip::register_validator(
		network.clone(),
		(is_known, client.clone()),
		&spawner,
	);

	let validation_network = Arc::new(ValidationNetwork::new(
		message_validator,
		client.clone(),
		spawner.clone(),
	));

	let parachain_context = match build_parachain_context.build(
		client.clone(),
		spawner,
		validation_network.clone(),
	) {
		Ok(ctx) => ctx,
		Err(()) => {
Gavin Wood's avatar
Gavin Wood committed
355
			return Err("Could not build the parachain context!".into())
356
357
		}
	};
358

359
360
361
362
	let work = async move {
		let mut notification_stream = client.import_notification_stream();

		while let Some(notification) = notification_stream.next().await {
363
364
365
366
			macro_rules! try_fr {
				($e:expr) => {
					match $e {
						Ok(x) => x,
367
						Err(e) => return (future::err(Error::Polkadot(
368
369
							format!("{:?}", e)
						))),
370
					}
371
				}
372
			}
373

374
375
376
377
378
379
380
381
382
			let relay_parent = notification.hash;
			let id = BlockId::hash(relay_parent);

			let network = network.clone();
			let client = client.clone();
			let key = key.clone();
			let parachain_context = parachain_context.clone();
			let validation_network = validation_network.clone();

383
			let work = future::lazy(move |_| async move {
384
385
386
				let api = client.runtime_api();
				let status = match try_fr!(api.parachain_status(&id, para_id)) {
					Some(status) => status,
387
					None => return future::ok(()),
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
				};

				let validators = try_fr!(api.validators(&id));

				let targets = compute_targets(
					para_id,
					validators.as_slice(),
					try_fr!(api.duty_roster(&id)),
				);

				let context = ApiContext {
					network: validation_network,
					parent_hash: relay_parent,
					validators,
				};

404
				if let Ok((collation, outgoing)) = collate(
405
406
407
408
409
410
					relay_parent,
					para_id,
					status,
					context,
					parachain_context,
					key,
411
				).await {
412
413
414
415
416
417
418
419
420
					network.with_spec(move |spec, ctx| {
						let res = spec.add_local_collation(
							ctx,
							relay_parent,
							targets,
							collation,
							outgoing,
						);

Gavin Wood's avatar
Gavin Wood committed
421
						tokio::spawn(res.boxed());
422
423
424
					});
				}
				future::ok(())
425
			});
426

427
			let deadlined = future::select(
428
				work.then(|f| f).boxed(),
429
430
431
432
433
434
435
436
437
				futures_timer::Delay::new(COLLATION_TIMEOUT)
			);

			let silenced = deadlined
				.map(|either| {
					if let future::Either::Right(_) = either {
						warn!("Collation failure: timeout");
					}
				});
438

Gavin Wood's avatar
Gavin Wood committed
439
				let future = silenced.map(drop);
440

441
			tokio::spawn(future);
442
443
		}
	}.boxed();
444

Gavin Wood's avatar
Gavin Wood committed
445
	service.spawn_essential_task("collation", work);
446

Gavin Wood's avatar
Gavin Wood committed
447
	Ok(service)
448
449
}

450
fn compute_targets(para_id: ParaId, session_keys: &[ValidatorId], roster: DutyRoster) -> HashSet<ValidatorId> {
451
452
453
454
455
456
457
458
459
	use polkadot_primitives::parachain::Chain;

	roster.validator_duty.iter().enumerate()
		.filter(|&(_, c)| c == &Chain::Parachain(para_id))
		.filter_map(|(i, _)| session_keys.get(i))
		.cloned()
		.collect()
}

460
461
/// Run a collator node with the given `RelayChainContext` and `ParachainContext`
/// build by the given `BuildParachainContext` and arguments to the underlying polkadot node.
462
463
///
/// This function blocks until done.
Gavin Wood's avatar
Gavin Wood committed
464
pub fn run_collator<P>(
465
	build_parachain_context: P,
466
	para_id: ParaId,
467
	key: Arc<CollatorPair>,
Gavin Wood's avatar
Gavin Wood committed
468
	config: Configuration,
469
) -> polkadot_cli::error::Result<()> where
470
	P: BuildParachainContext,
471
	P::ParachainContext: Send + 'static,
472
	<P::ParachainContext as ParachainContext>::ProduceCandidate: Send,
473
{
Gavin Wood's avatar
Gavin Wood committed
474
	match (config.expect_chain_spec().is_kusama(), config.roles) {
475
		(true, Roles::LIGHT) =>
Gavin Wood's avatar
Gavin Wood committed
476
477
478
479
480
481
482
483
			sc_cli::run_service_until_exit(config, |config| {
				run_collator_node(
					service::kusama_new_light(config, Some((key.public(), para_id)))?,
					para_id,
					key,
					build_parachain_context,
				)
			}),
484
		(true, _) =>
Gavin Wood's avatar
Gavin Wood committed
485
486
487
488
489
490
491
492
			sc_cli::run_service_until_exit(config, |config| {
				run_collator_node(
					service::kusama_new_full(config, Some((key.public(), para_id)), None, false, 6000)?,
					para_id,
					key,
					build_parachain_context,
				)
			}),
493
		(false, Roles::LIGHT) =>
Gavin Wood's avatar
Gavin Wood committed
494
495
496
497
498
499
500
501
			sc_cli::run_service_until_exit(config, |config| {
				run_collator_node(
					service::polkadot_new_light(config, Some((key.public(), para_id)))?,
					para_id,
					key,
					build_parachain_context,
				)
			}),
502
		(false, _) =>
Gavin Wood's avatar
Gavin Wood committed
503
504
505
506
507
508
509
510
			sc_cli::run_service_until_exit(config, |config| {
				run_collator_node(
					service::polkadot_new_full(config, Some((key.public(), para_id)), None, false, 6000)?,
					para_id,
					key,
					build_parachain_context,
				)
			}),
511
	}
512
513
}

Gav's avatar
Gav committed
514
515
#[cfg(test)]
mod tests {
516
	use std::collections::HashMap;
517
	use polkadot_primitives::parachain::{TargetedMessage, FeeSchedule};
518
	use keyring::Sr25519Keyring;
Gav's avatar
Gav committed
519
520
	use super::*;

521
522
523
	#[derive(Default, Clone)]
	struct DummyRelayChainContext {
		ingress: HashMap<ParaId, ConsolidatedIngress>
Gav's avatar
Gav committed
524
525
	}

526
	impl RelayChainContext for DummyRelayChainContext {
Gav's avatar
Gav committed
527
		type Error = ();
528
		type FutureEgress = Box<dyn Future<Output=Result<ConsolidatedIngress,()>> + Unpin>;
Gav's avatar
Gav committed
529

530
531
532
		fn unrouted_egress(&self, para_id: ParaId) -> Self::FutureEgress {
			match self.ingress.get(&para_id) {
				Some(ingress) => Box::new(future::ok(ingress.clone())),
533
				None => Box::new(future::pending()),
534
			}
Gav's avatar
Gav committed
535
		}
536
	}
Gav's avatar
Gav committed
537

538
539
540
541
	#[derive(Clone)]
	struct DummyParachainContext;

	impl ParachainContext for DummyParachainContext {
542
		type ProduceCandidate = future::Ready<Result<(BlockData, HeadData, OutgoingMessages), InvalidHead>>;
543

544
		fn produce_candidate<I: IntoIterator<Item=(ParaId, Message)>>(
545
			&mut self,
546
			_relay_parent: Hash,
547
			_status: ParachainStatus,
548
			ingress: I,
549
		) -> Self::ProduceCandidate {
550
			// send messages right back.
551
			future::ok((
552
553
				BlockData(vec![1, 2, 3, 4, 5,]),
				HeadData(vec![9, 9, 9]),
554
555
				OutgoingMessages {
					outgoing_messages: ingress.into_iter().map(|(id, msg)| TargetedMessage {
556
557
558
559
560
						target: id,
						data: msg.0,
					}).collect(),
				}
			))
Gav's avatar
Gav committed
561
562
563
		}
	}

564
	#[test]
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
	fn collates_correct_queue_roots() {
		let mut context = DummyRelayChainContext::default();

		let id = ParaId::from(100);

		let a = ParaId::from(123);
		let b = ParaId::from(456);

		let messages_from_a = vec![
			Message(vec![1, 1, 1]),
			Message(b"helloworld".to_vec()),
		];
		let messages_from_b = vec![
			Message(b"dogglesworth".to_vec()),
			Message(b"buy_1_chili_con_carne_here_is_my_cash".to_vec()),
		];

		let root_a = ::polkadot_validation::message_queue_root(
			messages_from_a.iter().map(|msg| &msg.0)
		);

		let root_b = ::polkadot_validation::message_queue_root(
			messages_from_b.iter().map(|msg| &msg.0)
		);

		context.ingress.insert(id, ConsolidatedIngress(vec![
			(b, messages_from_b),
			(a, messages_from_a),
		]));

595
		let future = collate(
596
			Default::default(),
597
			id,
598
599
600
601
602
603
604
605
			ParachainStatus {
				head_data: HeadData(vec![5]),
				balance: 10,
				fee_schedule: FeeSchedule {
					base: 0,
					per_byte: 1,
				},
			},
606
607
			context.clone(),
			DummyParachainContext,
608
			Arc::new(Sr25519Keyring::Alice.pair().into()),
609
610
611
		);

		let collation = futures::executor::block_on(future).unwrap().0;
612
613

		// ascending order by root.
614
		assert_eq!(collation.info.egress_queue_roots, vec![(a, root_a), (b, root_b)]);
Gav's avatar
Gav committed
615
616
	}
}