remove unused SubnetName map and use identity instead

pallets/subtensor/src/lib.rs

@@ -1061,9 +1061,6 @@ pub mod pallet {
     #[pallet::storage] // --- MAP ( netuid ) --> token_symbol | Returns the token symbol for a subnet.
     pub type TokenSymbol<T: Config> =
         StorageMap<_, Identity, u16, Vec<u8>, ValueQuery, DefaultUnicodeVecU8<T>>;
-    #[pallet::storage] // --- MAP ( netuid ) --> subnet_name | Returns the name of the subnet.
-    pub type SubnetName<T: Config> =
-        StorageMap<_, Identity, u16, Vec<u8>, ValueQuery, DefaultUnicodeVecU8<T>>;
 
     /// ============================
     /// ==== Global Parameters =====

pallets/subtensor/src/macros/hooks.rs

@@ -87,7 +87,9 @@ mod hooks {
                 // Remove all zero value entries in TotalHotkeyAlpha
                 .saturating_add(migrations::migrate_remove_zero_total_hotkey_alpha::migrate_remove_zero_total_hotkey_alpha::<T>())
                 // Wipe existing items to prevent bad decoding for new type
-                .saturating_add(migrations::migrate_upgrade_revealed_commitments::migrate_upgrade_revealed_commitments::<T>());
+                .saturating_add(migrations::migrate_upgrade_revealed_commitments::migrate_upgrade_revealed_commitments::<T>())
+				// Wipe unused SubnetName map
+				.saturating_add(migrations::migrate_remove_subnet_name_map::migrate_remove_subnet_name_map::<T>());
             weight
         }
 

pallets/subtensor/src/migrations/migrate_remove_subnet_name_map.rs

@@ -0,0 +1,61 @@
+use super::*;
+use crate::HasMigrationRun;
+use frame_support::{traits::Get, weights::Weight};
+use scale_info::prelude::string::String;
+use sp_io::{KillStorageResult, hashing::twox_128, storage::clear_prefix};
+
+fn remove_prefix<T: Config>(old_map: &str, weight: &mut Weight) {
+    let mut prefix = Vec::new();
+    prefix.extend_from_slice(&twox_128("SubtensorModule".as_bytes()));
+    prefix.extend_from_slice(&twox_128(old_map.as_bytes()));
+
+    let removal_results = clear_prefix(&prefix, Some(u32::MAX));
+
+    let removed_entries_count = match removal_results {
+        KillStorageResult::AllRemoved(removed) => removed as u64,
+        KillStorageResult::SomeRemaining(removed) => {
+            log::info!("Failed To Remove Some Items During migration");
+            removed as u64
+        }
+    };
+
+    log::info!(
+        "Removed {:?} entries from {:?} map.",
+        removed_entries_count,
+        old_map
+    );
+
+    *weight = (*weight).saturating_add(T::DbWeight::get().writes(removed_entries_count));
+}
+
+pub fn migrate_remove_subnet_name_map<T: Config>() -> Weight {
+    let migration_name = b"migrate_remove_subnet_name_map".to_vec();
+    let mut weight = T::DbWeight::get().reads(1);
+
+    if HasMigrationRun::<T>::get(&migration_name) {
+        log::info!(
+            "Migration '{:?}' has already run. Skipping.",
+            migration_name
+        );
+        return weight;
+    }
+
+    log::info!(
+        "Running migration '{}'",
+        String::from_utf8_lossy(&migration_name)
+    );
+
+    // Remove SubnetName
+    remove_prefix::<T>("SubnetName", &mut weight);
+
+    // 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

@@ -10,6 +10,7 @@ pub mod migrate_init_total_issuance;
 pub mod migrate_populate_owned_hotkeys;
 pub mod migrate_rao;
 pub mod migrate_remove_stake_map;
+pub mod migrate_remove_subnet_name_map;
 pub mod migrate_remove_unused_maps_and_values;
 pub mod migrate_remove_zero_total_hotkey_alpha;
 pub mod migrate_set_first_emission_block_number;