refactor/effective-balance

Sources/BeaconChain/BeaconChain.swift

@@ -238,10 +238,6 @@ extension BeaconChain {
         }
     }
 
-    static func getEffectiveBalance(state: BeaconState, index: ValidatorIndex) -> Gwei {
-        return min(state.validatorBalances[Int(index)], MAX_DEPOSIT_AMOUNT)
-    }
-
     static func getBitfieldBit(bitfield: Data, i: Int) -> Int {
         return Int((bitfield[i / 8] >> (i % 8))) % 2
     }
@@ -348,7 +344,7 @@ extension BeaconChain {
         }
 
         for (i, _) in state.validatorRegistry.enumerated() {
-            if getEffectiveBalance(state: state, index: ValidatorIndex(i)) >= MAX_DEPOSIT_AMOUNT {
+            if state.effectiveBalance(ValidatorIndex(i)) >= MAX_DEPOSIT_AMOUNT {
                 state.validatorRegistry[i].activate(state: state, genesis: true)
             }
         }
@@ -446,10 +442,10 @@ extension BeaconChain {
         assert(state.slot < state.validatorRegistry[Int(index)].withdrawableEpoch.startSlot())
         state.validatorRegistry[Int(index)].exit(state: state)
 
-        state.latestSlashedBalances[Int(getCurrentEpoch(state: state) % LATEST_SLASHED_EXIT_LENGTH)] += getEffectiveBalance(state: state, index: index)
+        state.latestSlashedBalances[Int(getCurrentEpoch(state: state) % LATEST_SLASHED_EXIT_LENGTH)] += state.effectiveBalance(index)
 
         let whistleblowerIndex = getBeaconProposerIndex(state: state, slot: state.slot)
-        let whistleblowerReward = getEffectiveBalance(state: state, index: index) / WHISTLEBLOWER_REWARD_QUOTIENT
+        let whistleblowerReward = state.effectiveBalance(index) / WHISTLEBLOWER_REWARD_QUOTIENT
 
         state.validatorBalances[Int(whistleblowerIndex)] += whistleblowerReward
         state.validatorBalances[Int(index)] -= whistleblowerReward

Sources/BeaconChain/DataStructures/State/BeaconState.swift

@@ -33,3 +33,10 @@ struct BeaconState {
     var eth1DataVotes: [Eth1DataVote]
     var depositIndex: UInt64
 }
+
+extension BeaconState {
+
+    func effectiveBalance(_ index: ValidatorIndex) -> Gwei {
+        return min(validatorBalances[Int(index)], MAX_DEPOSIT_AMOUNT)
+    }
+}

Sources/BeaconChain/Extensions/Array+AttestationTarget.swift

@@ -10,7 +10,7 @@ extension Array where Element == AttestationTarget {
                 return nil
             }
 
-            return BeaconChain.getEffectiveBalance(state: state, index: index) / FORK_CHOICE_BALANCE_INCREMENT
+            return state.effectiveBalance(index) / FORK_CHOICE_BALANCE_INCREMENT
         }
         .reduce(0, +)
     }

Sources/BeaconChain/Extensions/Array+ValidatorIndex.swift

@@ -3,6 +3,6 @@ import Foundation
 extension Array where Element == ValidatorIndex {
 
     func totalBalance(state: BeaconState) -> Gwei {
-        return map { BeaconChain.getEffectiveBalance(state: state, index: $0) }.reduce(0, +)
+        return map { state.effectiveBalance($0) }.reduce(0, +)
     }
 }

Sources/BeaconChain/StateTransition.swift

@@ -672,7 +672,7 @@ extension StateTransition {
             let totalAtStart = state.latestSlashedBalances[Int((epochIndex + 1) % LATEST_SLASHED_EXIT_LENGTH)]
             let totalAtEnd = state.latestSlashedBalances[Int(epochIndex)]
             let totalPenalties = totalAtEnd - totalAtStart
-            let penalty = BeaconChain.getEffectiveBalance(state: state, index: ValidatorIndex(i)) * min(totalPenalties * 3, totalBalance) / totalBalance
+            let penalty = state.effectiveBalance(ValidatorIndex(i)) * min(totalPenalties * 3, totalBalance) / totalBalance
             state.validatorBalances[i] -= penalty
         }
     }
@@ -712,7 +712,7 @@ extension StateTransition {
         var balanceChurn = UInt64(0)
         for (i, v) in state.validatorRegistry.enumerated() {
             if v.activationEpoch == FAR_FUTURE_EPOCH && state.validatorBalances[Int(i)] >= MAX_DEPOSIT_AMOUNT {
-                balanceChurn += BeaconChain.getEffectiveBalance(state: state, index: ValidatorIndex(i))
+                balanceChurn += state.effectiveBalance(ValidatorIndex(i))
                 if balanceChurn > maxBalanceChurn {
                     break
                 }
@@ -724,7 +724,7 @@ extension StateTransition {
         balanceChurn = 0
         for (i, v) in state.validatorRegistry.enumerated() {
             if v.activationEpoch == FAR_FUTURE_EPOCH && v.initiatedExit {
-                balanceChurn += BeaconChain.getEffectiveBalance(state: state, index: ValidatorIndex(i))
+                balanceChurn += state.effectiveBalance(ValidatorIndex(i))
                 if balanceChurn > maxBalanceChurn {
                     break
                 }
@@ -817,7 +817,7 @@ extension StateTransition {
     }
 
     private static func baseReward(state: BeaconState, index: ValidatorIndex, baseRewardQuotient: UInt64) -> UInt64 {
-        return BeaconChain.getEffectiveBalance(state: state, index: index) / baseRewardQuotient / 5
+        return state.effectiveBalance(index) / baseRewardQuotient / 5
     }
 
     private static func inactivityPenalty(
@@ -826,7 +826,7 @@ extension StateTransition {
         epochsSinceFinality: UInt64,
         baseRewardQuotient: UInt64
     ) -> UInt64 {
-        return baseReward(state: state, index: index, baseRewardQuotient: baseRewardQuotient) + BeaconChain.getEffectiveBalance(state: state, index: index) * epochsSinceFinality / INACTIVITY_PENALTY_QUOTIENT / 2
+        return baseReward(state: state, index: index, baseRewardQuotient: baseRewardQuotient) + state.effectiveBalance(index) * epochsSinceFinality / INACTIVITY_PENALTY_QUOTIENT / 2
     }
 
     private static func attestingValidators(