Dispute distribution implementation (#3282)

* Dispute protocol.

* Dispute distribution protocol.

* Get network requests routed.

* WIP: Basic dispute sender logic.

* Basic validator determination logic.

* WIP: Getting things to typecheck.

* Slightly larger timeout.

* More typechecking stuff.

* Cleanup.

* Finished most of the sending logic.

* Handle active leaves updates

- Cleanup dead disputes
- Update sends for new sessions
- Retry on errors

* Pass sessions in already.

* Startup dispute sending.

* Provide incoming decoding facilities

and use them in statement-distribution.

* Relaxed runtime util requirements.

We only need a `SubsystemSender` not a full `SubsystemContext`.

* Better usability of incoming requests.

Make it possible to consume stuff without clones.

* Add basic receiver functionality.

* Cleanup + fixes for sender.

* One more sender fix.

* Start receiver.

* Make sure to send responses back.

* WIP: Exposed authority discovery

* Make tests pass.

* Fully featured receiver.

* Decrease cost of `NotAValidator`.

* Make `RuntimeInfo` LRU cache size configurable.

* Cache more sessions.

* Fix collator protocol.

* Disable metrics for now.

* Make dispute-distribution a proper subsystem.

* Fix naming.

* Code style fixes.

* Factored out 4x copied mock function.

* WIP: Tests.

* Whitespace cleanup.

* Accessor functions.

* More testing.

* More Debug instances.

* Fix busy loop.

* Working tests.

* More tests.

* Cleanup.

* Fix build.

* Basic receiving test.

* Non validator message gets dropped.

* More receiving tests.

* Test nested and subsequent imports.

* Fix spaces.

* Better formatted imports.

* Import cleanup.

* Metrics.

* Message -> MuxedMessage

* Message -> MuxedMessage

* More review remarks.

* Add missing metrics.rs.

* Fix flaky test.

* Dispute coordinator - deliver confirmations.

* Send out `DisputeMessage` on issue local statement.

* Unwire dispute distribution.

* Review remarks.

* Review remarks.

* Better docs.

polkadot/node/subsystem-test-helpers/src/lib.rs

@@ -38,6 +38,9 @@ use std::sync::Arc;
 use std::task::{Context, Poll, Waker};
 use std::time::Duration;
 
+/// Generally useful mock data providers for unit tests.
+pub mod mock;
+
 enum SinkState<T> {
 	Empty {
 		read_waker: Option<Waker>,
@@ -310,7 +313,7 @@ pub fn make_subsystem_context<M, S>(
 ///
 /// Pass in two async closures: one mocks the overseer, the other runs the test from the perspective of a subsystem.
 ///
-/// Times out in two seconds.
+/// Times out in 5 seconds.
 pub fn subsystem_test_harness<M, OverseerFactory, Overseer, TestFactory, Test>(
 	overseer_factory: OverseerFactory,
 	test_factory: TestFactory,
@@ -329,7 +332,7 @@ pub fn subsystem_test_harness<M, OverseerFactory, Overseer, TestFactory, Test>(
 
 	futures::executor::block_on(async move {
 		future::join(overseer, test)
-			.timeout(Duration::from_secs(2))
+			.timeout(Duration::from_secs(5))
 			.await
 			.expect("test timed out instead of completing")
 	});

polkadot/node/subsystem-test-helpers/src/mock.rs

@@ -0,0 +1,46 @@
+// Copyright 2021 Parity Technologies (UK) Ltd.
+// 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/>.
+
+
+
+use std::sync::Arc;
+
+use sc_keystore::LocalKeystore;
+use sp_application_crypto::AppKey;
+use sp_keyring::Sr25519Keyring;
+use sp_keystore::{SyncCryptoStorePtr, SyncCryptoStore};
+
+use polkadot_primitives::v1::{ValidatorId, AuthorityDiscoveryId};
+
+
+/// Get mock keystore with `Ferdie` key.
+pub fn make_ferdie_keystore() -> SyncCryptoStorePtr {
+	let keystore: SyncCryptoStorePtr = Arc::new(LocalKeystore::in_memory());
+	SyncCryptoStore::sr25519_generate_new(
+		&*keystore,
+		ValidatorId::ID,
+		Some(&Sr25519Keyring::Ferdie.to_seed()),
+	)
+	.expect("Insert key into keystore");
+	SyncCryptoStore::sr25519_generate_new(
+		&*keystore,
+		AuthorityDiscoveryId::ID,
+		Some(&Sr25519Keyring::Ferdie.to_seed()),
+	)
+	.expect("Insert key into keystore");
+	keystore
+}
+