reset neuron data on deregistration

pallets/subtensor/src/subnets/uids.rs

@@ -9,6 +9,28 @@ impl<T: Config> Pallet<T> {
         SubnetworkN::<T>::get(netuid)
     }
 
+    /// Returns a callback that sets the element at the given position to zero, doing nothing if the
+    /// position is out of bounds
+    fn clear_element_at<N>(position: u16) -> impl Fn(&mut Vec<N>)
+    where
+        N: From<u8>,
+    {
+        move |vec: &mut Vec<N>| {
+            if vec.len() > position as usize {
+                vec[position as usize] = N::from(0);
+            };
+        }
+    }
+
+    /// Resets the trust, emission, consensus, incentive, dividends of the neuron to default
+    pub fn clear_neuron(netuid: u16, neuron_uid: u16) {
+        Emission::<T>::mutate(netuid, Self::clear_element_at(neuron_uid));
+        Trust::<T>::mutate(netuid, Self::clear_element_at(neuron_uid));
+        Consensus::<T>::mutate(netuid, Self::clear_element_at(neuron_uid));
+        Incentive::<T>::mutate(netuid, Self::clear_element_at(neuron_uid));
+        Dividends::<T>::mutate(netuid, Self::clear_element_at(neuron_uid));
+    }
+
     /// Replace the neuron under this uid.
     pub fn replace_neuron(
         netuid: u16,
@@ -45,6 +67,12 @@ impl<T: Config> Pallet<T> {
         Uids::<T>::insert(netuid, new_hotkey.clone(), uid_to_replace); // Make uid - hotkey association.
         BlockAtRegistration::<T>::insert(netuid, uid_to_replace, block_number); // Fill block at registration.
         IsNetworkMember::<T>::insert(new_hotkey.clone(), netuid, true); // Fill network is member.
+
+        // 4. Reset new neuron's values.
+        Self::clear_neuron(netuid, uid_to_replace);
+
+        // 4a. reset axon info for the new uid.
+        Axons::<T>::remove(netuid, old_hotkey);
     }
 
     /// Appends the uid to the network.

pallets/subtensor/tests/uids.rs

@@ -3,6 +3,7 @@
 use crate::mock::*;
 use frame_support::assert_ok;
 use frame_system::Config;
+use pallet_subtensor::*;
 use sp_core::U256;
 
 mod mock;
@@ -50,22 +51,45 @@ fn test_replace_neuron() {
         // Get UID
         let neuron_uid = SubtensorModule::get_uid_for_net_and_hotkey(netuid, &hotkey_account_id);
         assert_ok!(neuron_uid);
+        let neuron_uid = neuron_uid.unwrap();
+
+        // set non-default values
+        Trust::<Test>::mutate(netuid, |v| v[neuron_uid as usize] = 5u16);
+        Emission::<Test>::mutate(netuid, |v| v[neuron_uid as usize] = 5u64);
+        Consensus::<Test>::mutate(netuid, |v| v[neuron_uid as usize] = 5u16);
+        Incentive::<Test>::mutate(netuid, |v| v[neuron_uid as usize] = 5u16);
+        Dividends::<Test>::mutate(netuid, |v| v[neuron_uid as usize] = 5u16);
+
+        // serve axon mock address
+        let ip: u128 = 1676056785;
+        let port: u16 = 9999;
+        let ip_type: u8 = 4;
+        let hotkey = SubtensorModule::get_hotkey_for_net_and_uid(netuid, neuron_uid).unwrap();
+        assert!(SubtensorModule::serve_axon(
+            <<Test as Config>::RuntimeOrigin>::signed(hotkey_account_id),
+            netuid,
+            0,
+            ip,
+            port,
+            ip_type,
+            0,
+            0,
+            0
+        )
+        .is_ok());
 
         // Replace the neuron.
-        SubtensorModule::replace_neuron(
-            netuid,
-            neuron_uid.unwrap(),
-            &new_hotkey_account_id,
-            block_number,
-        );
+        SubtensorModule::replace_neuron(netuid, neuron_uid, &new_hotkey_account_id, block_number);
+
+        assert!(!SubtensorModule::has_axon_info(netuid, &hotkey));
 
         // Check old hotkey is not registered on any network.
         assert!(SubtensorModule::get_uid_for_net_and_hotkey(netuid, &hotkey_account_id).is_err());
         assert!(!SubtensorModule::is_hotkey_registered_on_any_network(
             &hotkey_account_id
         ));
 
-        let curr_hotkey = SubtensorModule::get_hotkey_for_net_and_uid(netuid, neuron_uid.unwrap());
+        let curr_hotkey = SubtensorModule::get_hotkey_for_net_and_uid(netuid, neuron_uid);
         assert_ok!(curr_hotkey);
         assert_ne!(curr_hotkey.unwrap(), hotkey_account_id);
 
@@ -77,6 +101,33 @@ fn test_replace_neuron() {
             &new_hotkey_account_id
         ));
         assert_eq!(curr_hotkey.unwrap(), new_hotkey_account_id);
+
+        // Check trust, emission, consensus, incentive, dividends have been reset to 0.
+        assert_eq!(SubtensorModule::get_trust_for_uid(netuid, neuron_uid), 0);
+        assert_eq!(SubtensorModule::get_emission_for_uid(netuid, neuron_uid), 0);
+        assert_eq!(
+            SubtensorModule::get_consensus_for_uid(netuid, neuron_uid),
+            0
+        );
+        assert_eq!(
+            SubtensorModule::get_incentive_for_uid(netuid, neuron_uid),
+            0
+        );
+        assert_eq!(
+            SubtensorModule::get_dividends_for_uid(netuid, neuron_uid),
+            0
+        );
+
+        assert!(!SubtensorModule::has_axon_info(
+            netuid,
+            &new_hotkey_account_id
+        ));
+
+        // Check axon info is reset.
+        let axon_info = SubtensorModule::get_axon_info(netuid, &curr_hotkey.unwrap());
+        assert_eq!(axon_info.ip, 0);
+        assert_eq!(axon_info.port, 0);
+        assert_eq!(axon_info.ip_type, 0);
     });
 }