Self-Vote for Staking (among others.) (#2078)

* initial doc for the staking module

* Remove md style links.

* Remove todos.

* Add rust code types

* Rename and fix review notes.

* Add new md file

* Final touches.

* Migrate compleatly to rustdoc

* Update link

* Fix heading

* Final touches wrt the new template.

* Remove empty prereq.

* Fix more reviews

* Some final nits.

* Fix some side issues.

* Fix another set of reviews

* Fix + stabilize leftover reivews.

* Remove unused test parameters

* Fix typo.

* Merge redundant loops

* Adds phantom self-vote

* Fix broken tests.

* Refactor some names to match the reference.

* Remove redundant inner loops from election round.

* Introduce phragmen post-processing.

* Some fixes and todos.

* Fix some tests with new phragmen params

* Fix test

* Bump spec

* Fix wasm build

* Fix tests and phragmen fallback. Avoid double-controlling

* Fix and rebuild wasm

* Whitespaces, whitespaces everywhere.

* Rebuild

* Disable post-processing.

* Identify by stash, not controller account.

* Couple of fixes

* Fix first test

* Fix invulnerability_should_work

* Fix a couple more tests

* Fix more tests

* Fix more tests

* Fix more tests

* Fix some tests

* Fix update-ledger.

* Fix update-ledger.

* Fix another test

* Fix another test

* Fix rest of staking tests

* Remove printlns

* Rebuild wasm

* Fix & tests for auth/val syncing

* Fix up threading for tests

* Remove superfluous asserts

node/cli/src/chain_spec.rs

@@ -107,7 +107,6 @@ fn staging_testnet_config_genesis() -> GenesisConfig {
 			current_era: 0,
 			offline_slash: Perbill::from_billionths(1_000_000),
 			session_reward: Perbill::from_billionths(2_065),
-			current_offline_slash: 0,
 			current_session_reward: 0,
 			validator_count: 7,
 			sessions_per_era: 12,
@@ -263,7 +262,6 @@ pub fn testnet_genesis(
 			bonding_duration: 2 * 60 * 12,
 			offline_slash: Perbill::zero(),
 			session_reward: Perbill::zero(),
-			current_offline_slash: 0,
 			current_session_reward: 0,
 			offline_slash_grace: 0,
 			stakers: initial_authorities.iter().map(|x| (x.0.clone(), x.1.clone(), STASH, StakerStatus::Validator)).collect(),

node/executor/src/lib.rs

@@ -308,7 +308,6 @@ mod tests {
 				bonding_duration: 0,
 				offline_slash: Perbill::zero(),
 				session_reward: Perbill::zero(),
-				current_offline_slash: 0,
 				current_session_reward: 0,
 				offline_slash_grace: 0,
 				invulnerables: vec![alice(), bob(), charlie()],
@@ -443,13 +442,7 @@ mod tests {
 			]
 		);
 
-		// let mut digest = generic::Digest::<Log>::default();
-		// digest.push(Log::from(::grandpa::RawLog::AuthoritiesChangeSignal(0, vec![
-		// 	(Keyring::Charlie.to_raw_public().into(), 1),
-		// 	(Keyring::Bob.to_raw_public().into(), 1),
-		// 	(Keyring::Alice.to_raw_public().into(), 1),
-		// ])));
-		let digest = generic::Digest::<Log>::default(); // TODO test this
+		let digest = generic::Digest::<Log>::default();
 		assert_eq!(Header::decode(&mut &block2.0[..]).unwrap().digest, digest);
 
 		(block1, block2)
@@ -578,14 +571,6 @@ mod tests {
 					phase: Phase::Finalization,
 					event: Event::session(session::RawEvent::NewSession(1))
 				},
-				// EventRecord { // TODO: this might be wrong.
-				// 	phase: Phase::Finalization,
-				// 	event: Event::grandpa(::grandpa::RawEvent::NewAuthorities(vec![
-				// 		(Keyring::Charlie.to_raw_public().into(), 1),
-				// 		(Keyring::Bob.to_raw_public().into(), 1),
-				// 		(Keyring::Alice.to_raw_public().into(), 1),
-				// 	])),
-				// },
 				EventRecord {
 					phase: Phase::Finalization,
 					event: Event::treasury(treasury::RawEvent::Spending(0))

node/runtime/src/lib.rs

@@ -58,8 +58,8 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	spec_name: create_runtime_str!("node"),
 	impl_name: create_runtime_str!("substrate-node"),
 	authoring_version: 10,
-	spec_version: 38,
-	impl_version: 40,
+	spec_version: 39,
+	impl_version: 39,
 	apis: RUNTIME_API_VERSIONS,
 };
 

srml/consensus/src/lib.rs

@@ -244,6 +244,12 @@ impl<T: Trait> Module<T> {
 		}
 	}
 
+	/// Set a single authority by index.
+	pub fn set_authority_count(count: u32) {
+		Self::save_original_authorities(None);
+		AuthorityStorageVec::<T::SessionKey>::set_count(count);
+	}
+
 	/// Set a single authority by index.
 	pub fn set_authority(index: u32, key: &T::SessionKey) {
 		let current_authority = AuthorityStorageVec::<T::SessionKey>::item(index);

srml/session/Cargo.toml

@@ -20,6 +20,7 @@ timestamp = { package = "srml-timestamp", path = "../timestamp", default-feature
 [dev-dependencies]
 substrate-primitives = { path = "../../core/primitives" }
 runtime_io = { package = "sr-io", path = "../../core/sr-io" }
+lazy_static = "1.0"
 
 [features]
 default = ["std"]

srml/session/src/lib.rs

@@ -184,17 +184,19 @@ impl<T: Trait> Module<T> {
 			<LastLengthChange<T>>::put(block_number);
 		}
 
+		T::OnSessionChange::on_session_change(time_elapsed, apply_rewards);
+
 		// Update any changes in session keys.
-		for (i, v) in Self::validators().into_iter().enumerate() {
+		let v = Self::validators();
+		<consensus::Module<T>>::set_authority_count(v.len() as u32);
+		for (i, v) in v.into_iter().enumerate() {
 			<consensus::Module<T>>::set_authority(
 				i as u32,
 				&<NextKeyFor<T>>::get(&v)
 					.or_else(|| T::ConvertAccountIdToSessionKey::convert(v))
 					.unwrap_or_default()
 			);
 		};
-
-		T::OnSessionChange::on_session_change(time_elapsed, apply_rewards);
 	}
 
 	/// Get the time that should have elapsed over a session if everything was working perfectly.
@@ -224,6 +226,7 @@ impl<T: Trait> OnFreeBalanceZero<T::AccountId> for Module<T> {
 #[cfg(test)]
 mod tests {
 	use super::*;
+	use std::cell::RefCell;
 	use srml_support::{impl_outer_origin, assert_ok};
 	use runtime_io::with_externalities;
 	use substrate_primitives::{H256, Blake2Hasher};
@@ -235,6 +238,17 @@ mod tests {
 		pub enum Origin for Test {}
 	}
 
+	thread_local!{
+		static NEXT_VALIDATORS: RefCell<Vec<u64>> = RefCell::new(vec![1, 2, 3]);
+	}
+
+	pub struct TestOnSessionChange;
+	impl OnSessionChange<u64> for TestOnSessionChange {
+		fn on_session_change(_elapsed: u64, _should_reward: bool) {
+			NEXT_VALIDATORS.with(|v| Session::set_validators(&*v.borrow()));
+		}
+	}
+
 	#[derive(Clone, Eq, PartialEq)]
 	pub struct Test;
 	impl consensus::Trait for Test {
@@ -261,7 +275,7 @@ mod tests {
 	}
 	impl Trait for Test {
 		type ConvertAccountIdToSessionKey = ConvertUintAuthorityId;
-		type OnSessionChange = ();
+		type OnSessionChange = TestOnSessionChange;
 		type Event = ();
 	}
 
@@ -273,14 +287,14 @@ mod tests {
 		let mut t = system::GenesisConfig::<Test>::default().build_storage().unwrap().0;
 		t.extend(consensus::GenesisConfig::<Test>{
 			code: vec![],
-			authorities: vec![UintAuthorityId(1), UintAuthorityId(2), UintAuthorityId(3)],
+			authorities: NEXT_VALIDATORS.with(|l| l.borrow().iter().cloned().map(UintAuthorityId).collect()),
 		}.build_storage().unwrap().0);
 		t.extend(timestamp::GenesisConfig::<Test>{
 			period: 5,
 		}.build_storage().unwrap().0);
 		t.extend(GenesisConfig::<Test>{
 			session_length: 2,
-			validators: vec![1, 2, 3],
+			validators: NEXT_VALIDATORS.with(|l| l.borrow().clone()),
 			keys: vec![],
 		}.build_storage().unwrap().0);
 		runtime_io::TestExternalities::new(t)
@@ -289,12 +303,35 @@ mod tests {
 	#[test]
 	fn simple_setup_should_work() {
 		with_externalities(&mut new_test_ext(), || {
-			assert_eq!(Consensus::authorities(), vec![UintAuthorityId(1).into(), UintAuthorityId(2).into(), UintAuthorityId(3).into()]);
+			assert_eq!(Consensus::authorities(), vec![UintAuthorityId(1), UintAuthorityId(2), UintAuthorityId(3)]);
 			assert_eq!(Session::length(), 2);
 			assert_eq!(Session::validators(), vec![1, 2, 3]);
 		});
 	}
 
+	#[test]
+	fn authorities_should_track_validators() {
+		with_externalities(&mut new_test_ext(), || {
+			NEXT_VALIDATORS.with(|v| *v.borrow_mut() = vec![1, 2]);
+			assert_ok!(Session::force_new_session(false));
+			Session::check_rotate_session(1);
+			assert_eq!(Session::validators(), vec![1, 2]);
+			assert_eq!(Consensus::authorities(), vec![UintAuthorityId(1), UintAuthorityId(2)]);
+
+			NEXT_VALIDATORS.with(|v| *v.borrow_mut() = vec![1, 2, 4]);
+			assert_ok!(Session::force_new_session(false));
+			Session::check_rotate_session(2);
+			assert_eq!(Session::validators(), vec![1, 2, 4]);
+			assert_eq!(Consensus::authorities(), vec![UintAuthorityId(1), UintAuthorityId(2), UintAuthorityId(4)]);
+
+			NEXT_VALIDATORS.with(|v| *v.borrow_mut() = vec![1, 2, 3]);
+			assert_ok!(Session::force_new_session(false));
+			Session::check_rotate_session(3);
+			assert_eq!(Session::validators(), vec![1, 2, 3]);
+			assert_eq!(Consensus::authorities(), vec![UintAuthorityId(1), UintAuthorityId(2), UintAuthorityId(3)]);
+		});
+	}
+
 	#[test]
 	fn should_work_with_early_exit() {
 		with_externalities(&mut new_test_ext(), || {