Use same hierarchy for hot and cold

This is nice as it enables us to avoid recomputing diffs, we can just copy.

Author: michaelsproul

beacon_node/beacon_chain/src/migrate.rs

@@ -632,7 +632,7 @@ impl<E: EthSpec, Hot: ItemStore<E>, Cold: ItemStore<E>> BackgroundMigrator<E, Ho
         // Compute the set of finalized state roots that we must keep to make the dynamic HDiff system
         // work.
         let required_finalized_diff_state_slots = store
-            .hierarchy_hot
+            .hierarchy
             .closest_layer_points(new_finalized_slot, store.hot_hdiff_start_slot()?);
 
         // We don't know which blocks are shared among abandoned chains, so we buffer and delete

beacon_node/store/src/config.rs

@@ -65,19 +65,18 @@ pub struct StoreConfig {
 
 /// Variant of `StoreConfig` that gets written to disk. Contains immutable configuration params.
 #[superstruct(
-    variants(V1, V22, V24),
+    variants(V1, V22),
     variant_attributes(derive(Debug, Clone, PartialEq, Eq, Encode, Decode))
 )]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct OnDiskStoreConfig {
     #[superstruct(only(V1))]
     pub slots_per_restore_point: u64,
     /// Prefix byte to future-proof versions of the `OnDiskStoreConfig` post V1
-    #[superstruct(only(V22, V24))]
+    #[superstruct(only(V22))]
     version_byte: u8,
-    #[superstruct(only(V22, V24))]
+    #[superstruct(only(V22))]
     pub hierarchy_config: HierarchyConfig,
-    // TODO(hdiff): Should persist the hot hierarchy_config too?
 }
 
 impl OnDiskStoreConfigV22 {
@@ -225,7 +224,6 @@ impl StoreItem for OnDiskStoreConfig {
         match self {
             OnDiskStoreConfig::V1(value) => value.as_ssz_bytes(),
             OnDiskStoreConfig::V22(value) => value.as_ssz_bytes(),
-            OnDiskStoreConfig::V24(value) => value.as_ssz_bytes(),
         }
     }
 
@@ -237,8 +235,6 @@ impl StoreItem for OnDiskStoreConfig {
             return Ok(Self::V1(value));
         }
 
-        // TODO(hdiff): handle V24 conversion
-
         Ok(Self::V22(OnDiskStoreConfigV22::from_ssz_bytes(bytes)?))
     }
 }

beacon_node/store/src/hot_cold_store.rs

@@ -58,8 +58,7 @@ pub struct HotColdDB<E: EthSpec, Hot: ItemStore<E>, Cold: ItemStore<E>> {
     /// The starting slots for the range of data columns stored in the database.
     data_column_info: RwLock<DataColumnInfo>,
     pub(crate) config: StoreConfig,
-    pub(crate) hierarchy: HierarchyModuli,
-    pub hierarchy_hot: HierarchyModuli,
+    pub hierarchy: HierarchyModuli,
     /// Cold database containing compact historical data.
     pub cold_db: Cold,
     /// Database containing blobs. If None, store falls back to use `cold_db`.
@@ -209,11 +208,9 @@ impl<E: EthSpec> HotColdDB<E, MemoryStore<E>, MemoryStore<E>> {
         config.verify::<E>()?;
 
         let hierarchy = config.hierarchy_config.to_moduli()?;
-        // TODO(hdiff): Use different exponents
+
         // NOTE: Anchor slot is initialized to 0, which is only valid for new DBs. We shouldn't
         // be reusing memory stores, but if we want to do that we should redo this.
-        let hierarchy_hot = config.hierarchy_config.to_moduli()?;
-
         let db = HotColdDB {
             split: RwLock::new(Split::default()),
             anchor_info: RwLock::new(ANCHOR_UNINITIALIZED),
@@ -233,7 +230,6 @@ impl<E: EthSpec> HotColdDB<E, MemoryStore<E>, MemoryStore<E>> {
             )),
             config,
             hierarchy,
-            hierarchy_hot,
             spec,
             _phantom: PhantomData,
         };
@@ -260,9 +256,6 @@ impl<E: EthSpec> HotColdDB<E, BeaconNodeBackend<E>, BeaconNodeBackend<E>> {
 
         let hierarchy = config.hierarchy_config.to_moduli()?;
 
-        // TODO(hdiff): Use different exponents
-        let hierarchy_hot = config.hierarchy_config.to_moduli()?;
-
         debug!(?hot_path, "Opening LevelDB");
         let hot_db = BeaconNodeBackend::open(&config, hot_path)?;
 
@@ -288,7 +281,6 @@ impl<E: EthSpec> HotColdDB<E, BeaconNodeBackend<E>, BeaconNodeBackend<E>> {
             )),
             config,
             hierarchy,
-            hierarchy_hot,
             spec,
             _phantom: PhantomData,
         };
@@ -451,7 +443,7 @@ impl<E: EthSpec, Hot: ItemStore<E>, Cold: ItemStore<E>> HotColdDB<E, Hot, Cold>
 
     pub fn hot_storage_strategy(&self, slot: Slot) -> Result<StorageStrategy, Error> {
         Ok(self
-            .hierarchy_hot
+            .hierarchy
             .storage_strategy(slot, self.hot_hdiff_start_slot()?)?)
     }