introduce black swan event e.g. disable everybody

Signed-off-by: Uncle Stinky <uncle.stinky@ghostchain.io>

pallets/slow-clap/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ghost-slow-clap"
-version = "0.3.52"
+version = "0.3.53"
 description = "Applause protocol for the EVM bridge"
 license.workspace = true
 authors.workspace = true

pallets/slow-clap/src/lib.rs

@@ -9,8 +9,7 @@ use frame_support::{
     pallet_prelude::*,
     traits::{
         tokens::fungible::{Inspect, Mutate},
-        DisabledValidators, EstimateNextSessionRotation, Get, OneSessionHandler, ValidatorSet,
-        ValidatorSetWithIdentification,
+        DisabledValidators, Get, OneSessionHandler, ValidatorSet, ValidatorSetWithIdentification,
     },
     WeakBoundedVec,
 };
@@ -35,11 +34,7 @@ use sp_staking::{
     offence::{Kind, Offence, ReportOffence},
     SessionIndex,
 };
-use sp_std::{
-    collections::btree_map::BTreeMap,
-    prelude::*,
-    vec::Vec,
-};
+use sp_std::{collections::btree_map::BTreeMap, prelude::*, vec::Vec};
 
 use ghost_networks::{
     NetworkData, NetworkDataBasicHandler, NetworkDataInspectHandler, NetworkDataMutateHandler,
@@ -186,7 +181,6 @@ pub mod pallet {
             + MaybeSerializeDeserialize
             + MaxEncodedLen;
 
-        type NextSessionRotation: EstimateNextSessionRotation<BlockNumberFor<Self>>;
         type ValidatorSet: ValidatorSetWithIdentification<Self::AccountId>;
         type Currency: Inspect<Self::AccountId> + Mutate<Self::AccountId>;
         type NetworkDataHandler: NetworkDataBasicHandler
@@ -215,12 +209,16 @@ pub mod pallet {
         #[pallet::constant]
         type HistoryDepth: Get<SessionIndex>;
 
+        #[pallet::constant]
+        type MinAuthoritiesNumber: Get<u32>;
+
         type WeightInfo: WeightInfo;
     }
 
     #[pallet::event]
     #[pallet::generate_deposit(pub(super) fn deposit_event)]
     pub enum Event<T: Config> {
+        BlackSwan,
         AuthoritiesEquilibrium,
         SomeAuthoritiesTrottling {
             throttling: Vec<IdentificationTuple<T>>,
@@ -628,7 +626,8 @@ impl<T: Config> Pallet<T> {
         let curr_received_claps_key = (curr_session_index, &transaction_hash, &clap_unique_hash);
 
         let mut previous_claps = ClapsInSession::<T>::get(&prev_session_index);
-        let mut total_received_claps = ReceivedClaps::<T>::get(&prev_received_claps_key).into_inner();
+        let mut total_received_claps =
+            ReceivedClaps::<T>::get(&prev_received_claps_key).into_inner();
 
         for (auth_index, info) in ClapsInSession::<T>::get(&curr_session_index).iter() {
             if !info.disabled {
@@ -656,14 +655,9 @@ impl<T: Config> Pallet<T> {
             }
         }
 
-        let disabled_authorities = previous_claps
-            .values()
-            .filter(|info| info.disabled)
-            .count();
+        let disabled_authorities = previous_claps.values().filter(|info| info.disabled).count();
 
-        let active_authorities = prev_authorities
-            .len()
-            .saturating_sub(disabled_authorities);
+        let active_authorities = prev_authorities.len().saturating_sub(disabled_authorities);
 
         let clap = Clap {
             authority_index: Default::default(),
@@ -676,10 +670,9 @@ impl<T: Config> Pallet<T> {
             amount,
         };
 
-        let enough_authorities = Perbill::from_rational(
-            total_received_claps.len() as u32,
-            active_authorities as u32,
-        ) > Perbill::from_percent(T::ApplauseThreshold::get());
+        let enough_authorities =
+            Perbill::from_rational(total_received_claps.len() as u32, active_authorities as u32)
+                > Perbill::from_percent(T::ApplauseThreshold::get());
 
         ensure!(enough_authorities, Error::<T>::NotEnoughClaps);
         Self::try_applause(&clap, &prev_received_claps_key)?;
@@ -906,8 +899,8 @@ impl<T: Config> Pallet<T> {
             EvmResponseType::TransactionLogs(evm_logs) => {
                 if ClapsInSession::<T>::get(&session_index)
                     .get(&authority_index)
-                        .map(|info| info.disabled)
-                        .unwrap_or_default()
+                    .map(|info| info.disabled)
+                    .unwrap_or_default()
                 {
                     log::info!(
                         target: LOG_TARGET,
@@ -1225,8 +1218,21 @@ impl<T: Config> OneSessionHandler<T::AccountId> for Pallet<T> {
             })
             .collect::<Vec<IdentificationTuple<T>>>();
 
-        if offenders.is_empty() {
+        let disabled_validators = T::DisabledValidators::disabled_validators()
+            .into_iter()
+            .count();
+
+        let offenders_length = offenders.len();
+        let authorities_left: u32 = authorities_len
+            .saturating_sub(disabled_validators)
+            .saturating_sub(offenders_length)
+            .try_into()
+            .unwrap_or_default();
+
+        if offenders_length == 0 {
             Self::deposit_event(Event::<T>::AuthoritiesEquilibrium);
+        } else if authorities_left < T::MinAuthoritiesNumber::get() {
+            Self::deposit_event(Event::<T>::BlackSwan);
         } else {
             Self::deposit_event(Event::<T>::SomeAuthoritiesTrottling {
                 throttling: offenders.clone(),

pallets/slow-clap/src/mock.rs

@@ -3,7 +3,6 @@
 use frame_support::{
     derive_impl, parameter_types,
     traits::{ConstU32, ConstU64},
-    weights::Weight,
 };
 use frame_system::EnsureRoot;
 use pallet_session::historical as pallet_session_historical;
@@ -140,27 +139,6 @@ parameter_types! {
     pub static MockAverageSessionLength: Option<u64> = None;
 }
 
-pub struct TestNextSessionRotation;
-impl frame_support::traits::EstimateNextSessionRotation<u64> for TestNextSessionRotation {
-    fn average_session_length() -> u64 {
-        let mock = MockAverageSessionLength::mutate(|p| p.take());
-        mock.unwrap_or(pallet_session::PeriodicSessions::<Period, Offset>::average_session_length())
-    }
-
-    fn estimate_current_session_progress(now: u64) -> (Option<Permill>, Weight) {
-        let (estimate, weight) =
-            pallet_session::PeriodicSessions::<Period, Offset>::estimate_current_session_progress(
-                now,
-            );
-        let mock = MockCurrentSessionProgress::mutate(|p| p.take());
-        (mock.unwrap_or(estimate), weight)
-    }
-
-    fn estimate_next_session_rotation(now: u64) -> (Option<u64>, Weight) {
-        pallet_session::PeriodicSessions::<Period, Offset>::estimate_next_session_rotation(now)
-    }
-}
-
 impl ghost_networks::Config for Runtime {
     type RuntimeEvent = RuntimeEvent;
     type Currency = Balances;
@@ -200,7 +178,6 @@ impl Config for Runtime {
     type RuntimeEvent = RuntimeEvent;
     type AuthorityId = UintAuthorityId;
 
-    type NextSessionRotation = TestNextSessionRotation;
     type ValidatorSet = Historical;
     type Currency = Balances;
     type NetworkDataHandler = Networks;
@@ -210,9 +187,10 @@ impl Config for Runtime {
 
     type MaxAuthorities = ConstU32<5>;
     type ApplauseThreshold = ConstU32<50>;
-    type OffenceThreshold = ConstU32<75>;
+    type OffenceThreshold = ConstU32<0>;
     type UnsignedPriority = ConstU64<{ 1 << 20 }>;
     type HistoryDepth = HistoryDepth;
+    type MinAuthoritiesNumber = ConstU32<2>;
 
     type WeightInfo = ();
 }

pallets/slow-clap/src/tests.rs

@@ -979,7 +979,8 @@ fn should_self_applause_after_diabled() {
         let curr_session_index = Session::session_index();
 
         pallet::ClapsInSession::<Runtime>::mutate(&session_index, |claps| {
-            claps.entry(1 as AuthIndex)
+            claps
+                .entry(1 as AuthIndex)
                 .and_modify(|individual| (*individual).disabled = true)
                 .or_insert(SessionAuthorityInfo {
                     claps: 0u32,
@@ -988,7 +989,8 @@ fn should_self_applause_after_diabled() {
         });
 
         pallet::ClapsInSession::<Runtime>::mutate(&curr_session_index, |claps| {
-            claps.entry(2 as AuthIndex)
+            claps
+                .entry(2 as AuthIndex)
                 .and_modify(|individual| (*individual).disabled = true)
                 .or_insert(SessionAuthorityInfo {
                     claps: 0u32,
@@ -1207,6 +1209,22 @@ fn should_not_fail_on_sub_existential_balance() {
     });
 }
 
+#[test]
+fn should_emit_black_swan_if_not_enough_authorities_left() {
+    let (network_id, _, _) = generate_unique_hash(None, None, None, None);
+
+    new_test_ext().execute_with(|| {
+        let session_index = advance_session_and_get_index();
+        assert_ok!(do_clap_from(session_index, network_id, 0, false));
+        Session::disable_index(1);
+        Session::disable_index(2);
+
+        advance_session();
+        advance_session();
+        System::assert_has_event(RuntimeEvent::SlowClap(crate::Event::BlackSwan));
+    });
+}
+
 fn advance_session_and_get_index() -> u32 {
     advance_session();
     assert_eq!(Session::validators(), Vec::<u64>::new());