EpochProces: Prepare activeValidatorIndices for the next epoch

ChainSafe · Jul 22, 2021 · 7145a84 · 7145a84
1 parent 5428329
commit 7145a84
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Showing 3 changed files with 15 additions and 3 deletions.
diff --git a/packages/beacon-state-transition/src/allForks/stateTransition.ts b/packages/beacon-state-transition/src/allForks/stateTransition.ts
@@ -144,7 +144,7 @@ function processSlotsWithTransientCache(
         metrics?.registerValidatorStatuses(process.currentEpoch, process.statuses);
 
         postState.slot++;
-        rotateEpochs(postState.epochCtx, postState, process.indicesBounded);
+        rotateEpochs(postState.epochCtx, postState, process.indicesBounded, process.nextEpochActiveValidatorIndices);
       } finally {
         if (timer) timer();
       }

diff --git a/packages/beacon-state-transition/src/allForks/util/epochContext.ts b/packages/beacon-state-transition/src/allForks/util/epochContext.ts
@@ -31,6 +31,7 @@ import {
   computeStartSlotAtEpoch,
   getSeed,
   getTotalActiveBalance,
+  getTotalBalance,
   isAggregatorFromCommitteeLength,
   zipIndexesCommitteeBits,
 } from "../../util";
@@ -203,7 +204,8 @@ export function computeSyncParticipantReward(config: IBeaconConfig, totalActiveB
 export function rotateEpochs(
   epochCtx: EpochContext,
   state: allForks.BeaconState,
-  indicesBounded: [ValidatorIndex, Epoch, Epoch][]
+  indicesBounded: [ValidatorIndex, Epoch, Epoch][],
+  activeValidatorIndices: ValidatorIndex[]
 ): void {
   epochCtx.previousShuffling = epochCtx.currentShuffling;
   epochCtx.currentShuffling = epochCtx.nextShuffling;
@@ -213,7 +215,9 @@ export function rotateEpochs(
   epochCtx.proposers = computeProposers(state, epochCtx.currentShuffling);
 
   if (currEpoch >= epochCtx.config.ALTAIR_FORK_EPOCH) {
-    const totalActiveBalance = getTotalActiveBalance(state);
+    // calling getTotalActiveBalance would cause 1 extra validators loop
+    // here we leverage EpochProcess to prepare activeValidatorIndices
+    const totalActiveBalance = getTotalBalance(state, activeValidatorIndices);
     epochCtx.syncParticipantReward = computeSyncParticipantReward(epochCtx.config, totalActiveBalance);
     epochCtx.syncProposerReward =
       (epochCtx.syncParticipantReward * PROPOSER_WEIGHT) / (WEIGHT_DENOMINATOR - PROPOSER_WEIGHT);

diff --git a/packages/beacon-state-transition/src/allForks/util/epochProcess.ts b/packages/beacon-state-transition/src/allForks/util/epochProcess.ts
@@ -56,6 +56,7 @@ export interface IEpochProcess {
   balances?: BigUint64Array;
   // to be used for rotateEpochs()
   indicesBounded: [ValidatorIndex, Epoch, Epoch][];
+  nextEpochActiveValidatorIndices: ValidatorIndex[];
 }
 
 export function createIEpochProcess(): IEpochProcess {
@@ -80,6 +81,7 @@ export function createIEpochProcess(): IEpochProcess {
     statuses: [],
     validators: [],
     indicesBounded: [],
+    nextEpochActiveValidatorIndices: [],
   };
 }
 
@@ -90,6 +92,7 @@ export function prepareEpochProcessState<T extends allForks.BeaconState>(state:
   const forkName = config.getForkName(state.slot);
   const currentEpoch = epochCtx.currentShuffling.epoch;
   const prevEpoch = epochCtx.previousShuffling.epoch;
+  const nextEpoch = currentEpoch + 1;
   out.currentEpoch = currentEpoch;
   out.prevEpoch = prevEpoch;
 
@@ -145,6 +148,11 @@ export function prepareEpochProcessState<T extends allForks.BeaconState>(state:
 
     out.statuses.push(status);
     out.indicesBounded.push([i, v.activationEpoch, v.exitEpoch]);
+    if (nextEpoch >= config.ALTAIR_FORK_EPOCH) {
+      if (isActiveValidator(v, nextEpoch)) {
+        out.nextEpochActiveValidatorIndices.push(i);
+      }
+    }
   });
 
   if (out.totalActiveStake < EFFECTIVE_BALANCE_INCREMENT) {