use migration to clear the old pending em map

Author: camfairchild

pallets/subtensor/src/coinbase/root.rs

@@ -314,7 +314,6 @@ impl<T: Config> Pallet<T> {
 
         // --- 15. Mechanism step / emissions bookkeeping.
         FirstEmissionBlockNumber::<T>::remove(netuid);
-        PendingEmission::<T>::remove(netuid);
         PendingValidatorEmission::<T>::remove(netuid);
         PendingServerEmission::<T>::remove(netuid);
         PendingRootAlphaDivs::<T>::remove(netuid);

pallets/subtensor/src/coinbase/run_coinbase.rs

@@ -262,23 +262,6 @@ impl<T: Config> Pallet<T> {
                 BlocksSinceLastStep::<T>::insert(netuid, 0);
                 LastMechansimStepBlock::<T>::insert(netuid, current_block);
 
-                // Get and drain the PendingEmission.
-                // deprecated
-                let pending_emission = PendingEmission::<T>::get(netuid);
-                PendingEmission::<T>::insert(netuid, AlphaCurrency::ZERO);
-                // If pending_emission is not zero, we split it between the server emission and the validator emission.
-                if !pending_emission.is_zero() {
-                    let server_alpha = pending_emission.saturating_div(2.into());
-                    let validator_alpha = pending_emission.saturating_sub(server_alpha);
-
-                    PendingServerEmission::<T>::mutate(netuid, |total| {
-                        *total = total.saturating_add(server_alpha)
-                    });
-                    PendingValidatorEmission::<T>::mutate(netuid, |total| {
-                        *total = total.saturating_add(validator_alpha)
-                    });
-                }
-
                 // Get and drain the subnet pending emission.
                 let pending_server_alpha = PendingServerEmission::<T>::get(netuid);
                 PendingServerEmission::<T>::insert(netuid, AlphaCurrency::ZERO);

pallets/subtensor/src/lib.rs

@@ -1430,10 +1430,6 @@ pub mod pallet {
     pub type NetworkRegisteredAt<T: Config> =
         StorageMap<_, Identity, NetUid, u64, ValueQuery, DefaultNetworkRegisteredAt<T>>;
     #[pallet::storage]
-    /// --- MAP ( netuid ) --> pending_emission
-    pub type PendingEmission<T> =
-        StorageMap<_, Identity, NetUid, AlphaCurrency, ValueQuery, DefaultPendingEmission<T>>;
-    #[pallet::storage]
     /// --- MAP ( netuid ) --> pending_server_emission
     pub type PendingServerEmission<T> =
         StorageMap<_, Identity, NetUid, AlphaCurrency, ValueQuery, DefaultZeroAlpha<T>>;

pallets/subtensor/src/macros/hooks.rs

@@ -161,7 +161,9 @@ mod hooks {
                 // Remove obsolete map entries
                 .saturating_add(migrations::migrate_remove_tao_dividends::migrate_remove_tao_dividends::<T>())
                 // Re-init tao flows
-                .saturating_add(migrations::migrate_init_tao_flow::migrate_init_tao_flow::<T>());
+                .saturating_add(migrations::migrate_init_tao_flow::migrate_init_tao_flow::<T>())
+                // Migrate pending emissions
+                .saturating_add(migrations::migrate_pending_emissions::migrate_pending_emissions::<T>());
             weight
         }
 

pallets/subtensor/src/migrations/migrate_pending_emissions.rs

@@ -0,0 +1,73 @@
+use super::*;
+use frame_support::{storage_alias, traits::Get, weights::Weight};
+use substrate_fixed::types::U96F32;
+
+pub mod deprecated_pending_emission_format {
+    use super::*;
+
+    #[storage_alias]
+    pub(super) type PendingEmission<T: Config> =
+        StorageMap<Pallet<T>, Identity, NetUid, AlphaCurrency, ValueQuery>;
+}
+
+pub fn migrate_pending_emissions<T: Config>() -> Weight {
+    let migration_name = b"migrate_pending_emissions".to_vec();
+    let mut weight: Weight = T::DbWeight::get().reads(1);
+
+    // Skip if already executed
+    if HasMigrationRun::<T>::get(&migration_name) {
+        log::info!(
+            target: "runtime",
+            "Migration '{}' already run - skipping.",
+            String::from_utf8_lossy(&migration_name)
+        );
+        return weight;
+    }
+    log::info!(
+        "Running migration '{}'",
+        String::from_utf8_lossy(&migration_name)
+    );
+
+    // Pull from PendingEmission and distribute to PendingValidatorEmission and PendingServerEmission
+    for (netuid, pending_emission) in
+        deprecated_pending_emission_format::PendingEmission::<T>::iter()
+    {
+        // Split up the pending emission into server and validator emission
+        // Server emission is pending+root_alpha times the 50% miner cut.
+        let root_alpha: U96F32 =
+            U96F32::saturating_from_num(PendingRootAlphaDivs::<T>::get(netuid).to_u64());
+        let server_emission_float: U96F32 = U96F32::saturating_from_num(pending_emission.to_u64())
+            .saturating_add(root_alpha)
+            .saturating_div(U96F32::saturating_from_num(2));
+        let server_emission: AlphaCurrency =
+            server_emission_float.saturating_to_num::<u64>().into();
+        let validator_emission = pending_emission.saturating_sub(server_emission);
+
+        PendingValidatorEmission::<T>::mutate(netuid, |total| {
+            *total = total.saturating_add(validator_emission)
+        });
+        PendingServerEmission::<T>::mutate(netuid, |total| {
+            *total = total.saturating_add(server_emission)
+        });
+
+        weight = weight.saturating_add(T::DbWeight::get().reads_writes(1, 2));
+    }
+
+    // Kill the map
+    let removal_result =
+        deprecated_pending_emission_format::PendingEmission::<T>::clear(u32::MAX, None);
+    weight = weight.saturating_add(
+        T::DbWeight::get().reads_writes(removal_result.loops as u64, removal_result.backend as u64),
+    );
+
+    // Mark Migration as Completed
+    HasMigrationRun::<T>::insert(&migration_name, true);
+    weight = weight.saturating_add(T::DbWeight::get().writes(1));
+
+    log::info!(
+        "Migration '{:?}' completed successfully.",
+        String::from_utf8_lossy(&migration_name)
+    );
+
+    weight
+}

pallets/subtensor/src/migrations/mod.rs

@@ -27,6 +27,7 @@ pub mod migrate_network_immunity_period;
 pub mod migrate_network_lock_cost_2500;
 pub mod migrate_network_lock_reduction_interval;
 pub mod migrate_orphaned_storage_items;
+pub mod migrate_pending_emissions;
 pub mod migrate_populate_owned_hotkeys;
 pub mod migrate_rao;
 pub mod migrate_rate_limit_keys;