Speed up epoch transition using persistent vector

packages/lodestar-beacon-state-transition/src/fast/block/index.ts

@@ -1,5 +1,5 @@
-import {EpochContext} from "../util";
-import {BeaconBlock, BeaconState} from "@chainsafe/lodestar-types";
+import {EpochContext, CachedValidatorsBeaconState} from "../util";
+import {BeaconBlock} from "@chainsafe/lodestar-types";
 
 import {processBlockHeader} from "./processBlockHeader";
 import {processRandao} from "./processRandao";
@@ -25,7 +25,7 @@ export {
 
 export function processBlock(
   epochCtx: EpochContext,
-  state: BeaconState,
+  state: CachedValidatorsBeaconState,
   block: BeaconBlock,
   verifySignatures = true
 ): void {

packages/lodestar-beacon-state-transition/src/fast/block/initiateValidatorExit.ts

@@ -1,25 +1,27 @@
-import {readOnlyMap} from "@chainsafe/ssz";
-import {BeaconState, ValidatorIndex} from "@chainsafe/lodestar-types";
+import {ValidatorIndex} from "@chainsafe/lodestar-types";
 
 import {FAR_FUTURE_EPOCH} from "../../constants";
 import {computeActivationExitEpoch, getChurnLimit} from "../../util";
-import {EpochContext} from "../util";
+import {EpochContext, CachedValidatorsBeaconState} from "../util";
 
 /**
  * Initiate the exit of the validator with index ``index``.
  */
-export function initiateValidatorExit(epochCtx: EpochContext, state: BeaconState, index: ValidatorIndex): void {
+export function initiateValidatorExit(
+  epochCtx: EpochContext,
+  state: CachedValidatorsBeaconState,
+  index: ValidatorIndex
+): void {
   const config = epochCtx.config;
   // return if validator already initiated exit
-  const validator = state.validators[index];
-  if (validator.exitEpoch !== FAR_FUTURE_EPOCH) {
+  if (state.validators[index].exitEpoch !== FAR_FUTURE_EPOCH) {
     return;
   }
 
   const currentEpoch = epochCtx.currentShuffling.epoch;
 
   // compute exit queue epoch
-  const validatorExitEpochs = readOnlyMap(state.validators, (v) => v.exitEpoch);
+  const validatorExitEpochs = state.flatValidators().readOnlyMap((v) => v.exitEpoch);
   const exitEpochs = validatorExitEpochs.filter((exitEpoch) => exitEpoch !== FAR_FUTURE_EPOCH);
   exitEpochs.push(computeActivationExitEpoch(config, currentEpoch));
   let exitQueueEpoch = Math.max(...exitEpochs);
@@ -29,6 +31,8 @@ export function initiateValidatorExit(epochCtx: EpochContext, state: BeaconState
   }
 
   // set validator exit epoch and withdrawable epoch
-  validator.exitEpoch = exitQueueEpoch;
-  validator.withdrawableEpoch = validator.exitEpoch + config.params.MIN_VALIDATOR_WITHDRAWABILITY_DELAY;
+  state.setValidator(index, {
+    exitEpoch: exitQueueEpoch,
+    withdrawableEpoch: exitQueueEpoch + config.params.MIN_VALIDATOR_WITHDRAWABILITY_DELAY,
+  });
 }

packages/lodestar-beacon-state-transition/src/fast/block/processAttesterSlashing.ts

@@ -1,13 +1,13 @@
-import {AttesterSlashing, BeaconState, ValidatorIndex} from "@chainsafe/lodestar-types";
+import {AttesterSlashing, ValidatorIndex} from "@chainsafe/lodestar-types";
 
 import {isSlashableValidator, isSlashableAttestationData} from "../../util";
-import {EpochContext} from "../util";
+import {EpochContext, CachedValidatorsBeaconState} from "../util";
 import {slashValidator} from "./slashValidator";
 import {isValidIndexedAttestation} from "./isValidIndexedAttestation";
 
 export function processAttesterSlashing(
   epochCtx: EpochContext,
-  state: BeaconState,
+  state: CachedValidatorsBeaconState,
   attesterSlashing: AttesterSlashing,
   verifySignatures = true
 ): void {

packages/lodestar-beacon-state-transition/src/fast/block/processDeposit.ts

@@ -1,12 +1,12 @@
 import bls from "@chainsafe/bls";
-import {BeaconState, Deposit} from "@chainsafe/lodestar-types";
+import {Deposit} from "@chainsafe/lodestar-types";
 import {verifyMerkleBranch, bigIntMin} from "@chainsafe/lodestar-utils";
 
 import {DEPOSIT_CONTRACT_TREE_DEPTH, DomainType, FAR_FUTURE_EPOCH} from "../../constants";
 import {computeDomain, computeSigningRoot, increaseBalance} from "../../util";
-import {EpochContext} from "../util";
+import {EpochContext, CachedValidatorsBeaconState} from "../util";
 
-export function processDeposit(epochCtx: EpochContext, state: BeaconState, deposit: Deposit): void {
+export function processDeposit(epochCtx: EpochContext, state: CachedValidatorsBeaconState, deposit: Deposit): void {
   const config = epochCtx.config;
   const {EFFECTIVE_BALANCE_INCREMENT, MAX_EFFECTIVE_BALANCE} = config.params;
   // verify the merkle branch
@@ -43,7 +43,7 @@ export function processDeposit(epochCtx: EpochContext, state: BeaconState, depos
     }
 
     // add validator and balance entries
-    state.validators.push({
+    state.addValidator({
       pubkey: pubkey,
       withdrawalCredentials: deposit.data.withdrawalCredentials,
       activationEligibilityEpoch: FAR_FUTURE_EPOCH,

packages/lodestar-beacon-state-transition/src/fast/block/processOperations.ts

@@ -3,25 +3,29 @@ import {
   Attestation,
   AttesterSlashing,
   BeaconBlockBody,
-  BeaconState,
   Deposit,
   ProposerSlashing,
   VoluntaryExit,
 } from "@chainsafe/lodestar-types";
 
-import {EpochContext} from "../util";
+import {EpochContext, CachedValidatorsBeaconState} from "../util";
 import {processProposerSlashing} from "./processProposerSlashing";
 import {processAttesterSlashing} from "./processAttesterSlashing";
 import {processAttestation} from "./processAttestation";
 import {processDeposit} from "./processDeposit";
 import {processVoluntaryExit} from "./processVoluntaryExit";
 
 type Operation = ProposerSlashing | AttesterSlashing | Attestation | Deposit | VoluntaryExit;
-type OperationFunction = (epochCtx: EpochContext, state: BeaconState, op: Operation, verify: boolean) => void;
+type OperationFunction = (
+  epochCtx: EpochContext,
+  state: CachedValidatorsBeaconState,
+  op: Operation,
+  verify: boolean
+) => void;
 
 export function processOperations(
   epochCtx: EpochContext,
-  state: BeaconState,
+  state: CachedValidatorsBeaconState,
   body: BeaconBlockBody,
   verifySignatures = true
 ): void {

packages/lodestar-beacon-state-transition/src/fast/block/processProposerSlashing.ts

@@ -1,13 +1,13 @@
 import {BeaconState, ProposerSlashing} from "@chainsafe/lodestar-types";
 import {DomainType} from "../../constants";
 import {computeEpochAtSlot, computeSigningRoot, getDomain, isSlashableValidator} from "../../util";
-import {EpochContext} from "../util";
+import {EpochContext, CachedValidatorsBeaconState} from "../util";
 import {slashValidator} from "./slashValidator";
 import {ISignatureSet, SignatureSetType, verifySignatureSet} from "../signatureSets";
 
 export function processProposerSlashing(
   epochCtx: EpochContext,
-  state: BeaconState,
+  state: CachedValidatorsBeaconState,
   proposerSlashing: ProposerSlashing,
   verifySignatures = true
 ): void {

packages/lodestar-beacon-state-transition/src/fast/block/processVoluntaryExit.ts

@@ -2,12 +2,12 @@ import {BeaconState, SignedVoluntaryExit} from "@chainsafe/lodestar-types";
 import {DomainType, FAR_FUTURE_EPOCH} from "../../constants";
 import {computeSigningRoot, getDomain, isActiveValidator} from "../../util";
 import {ISignatureSet, SignatureSetType, verifySignatureSet} from "../signatureSets";
-import {EpochContext} from "../util";
+import {EpochContext, CachedValidatorsBeaconState} from "../util";
 import {initiateValidatorExit} from "./initiateValidatorExit";
 
 export function processVoluntaryExit(
   epochCtx: EpochContext,
-  state: BeaconState,
+  state: CachedValidatorsBeaconState,
   signedVoluntaryExit: SignedVoluntaryExit,
   verifySignature = true
 ): void {

packages/lodestar-beacon-state-transition/src/fast/block/slashValidator.ts

@@ -1,12 +1,12 @@
-import {BeaconState, ValidatorIndex} from "@chainsafe/lodestar-types";
+import {ValidatorIndex} from "@chainsafe/lodestar-types";
 
 import {decreaseBalance, increaseBalance} from "../../util";
-import {EpochContext} from "../util";
+import {EpochContext, CachedValidatorsBeaconState} from "../util";
 import {initiateValidatorExit} from "./initiateValidatorExit";
 
 export function slashValidator(
   epochCtx: EpochContext,
-  state: BeaconState,
+  state: CachedValidatorsBeaconState,
   slashedIndex: ValidatorIndex,
   whistleblowerIndex?: ValidatorIndex
 ): void {
@@ -19,8 +19,10 @@ export function slashValidator(
   const epoch = epochCtx.currentShuffling.epoch;
   initiateValidatorExit(epochCtx, state, slashedIndex);
   const validator = state.validators[slashedIndex];
-  validator.slashed = true;
-  validator.withdrawableEpoch = Math.max(validator.withdrawableEpoch, epoch + EPOCHS_PER_SLASHINGS_VECTOR);
+  state.setValidator(slashedIndex, {
+    slashed: true,
+    withdrawableEpoch: Math.max(validator.withdrawableEpoch, epoch + EPOCHS_PER_SLASHINGS_VECTOR),
+  });
   state.slashings[epoch % EPOCHS_PER_SLASHINGS_VECTOR] += validator.effectiveBalance;
   decreaseBalance(state, slashedIndex, validator.effectiveBalance / BigInt(MIN_SLASHING_PENALTY_QUOTIENT));
 

packages/lodestar-beacon-state-transition/src/fast/epoch/index.ts

@@ -1,6 +1,4 @@
-import {BeaconState} from "@chainsafe/lodestar-types";
-
-import {prepareEpochProcessState} from "../util";
+import {CachedValidatorsBeaconState, prepareEpochProcessState} from "../util";
 import {StateTransitionEpochContext} from "../util/epochContext";
 import {processJustificationAndFinalization} from "./processJustificationAndFinalization";
 import {processRewardsAndPenalties} from "./processRewardsAndPenalties";
@@ -20,7 +18,7 @@ export {
   getAttestationDeltas,
 };
 
-export function processEpoch(epochCtx: StateTransitionEpochContext, state: BeaconState): void {
+export function processEpoch(epochCtx: StateTransitionEpochContext, state: CachedValidatorsBeaconState): void {
   const process = prepareEpochProcessState(epochCtx, state);
   epochCtx.epochProcess = process;
   processJustificationAndFinalization(epochCtx, process, state);

packages/lodestar-beacon-state-transition/src/fast/epoch/processFinalUpdates.ts

@@ -1,11 +1,15 @@
 import {readOnlyMap, List} from "@chainsafe/ssz";
-import {BeaconState, Eth1Data, PendingAttestation} from "@chainsafe/lodestar-types";
+import {Eth1Data, PendingAttestation} from "@chainsafe/lodestar-types";
 import {bigIntMin, intDiv} from "@chainsafe/lodestar-utils";
 
 import {getRandaoMix} from "../../util";
-import {EpochContext, IEpochProcess} from "../util";
+import {EpochContext, IEpochProcess, CachedValidatorsBeaconState} from "../util";
 
-export function processFinalUpdates(epochCtx: EpochContext, process: IEpochProcess, state: BeaconState): void {
+export function processFinalUpdates(
+  epochCtx: EpochContext,
+  process: IEpochProcess,
+  state: CachedValidatorsBeaconState
+): void {
   const config = epochCtx.config;
   const currentEpoch = process.currentEpoch;
   const nextEpoch = currentEpoch + 1;
@@ -37,10 +41,9 @@ export function processFinalUpdates(epochCtx: EpochContext, process: IEpochProce
     const balance = balances[i];
     const effectiveBalance = status.validator.effectiveBalance;
     if (balance + DOWNWARD_THRESHOLD < effectiveBalance || effectiveBalance + UPWARD_THRESHOLD < balance) {
-      state.validators[i].effectiveBalance = bigIntMin(
-        balance - (balance % EFFECTIVE_BALANCE_INCREMENT),
-        MAX_EFFECTIVE_BALANCE
-      );
+      state.setValidator(i, {
+        effectiveBalance: bigIntMin(balance - (balance % EFFECTIVE_BALANCE_INCREMENT), MAX_EFFECTIVE_BALANCE),
+      });
     }
   }
 

packages/lodestar-beacon-state-transition/src/fast/epoch/processRegistryUpdates.ts

@@ -1,20 +1,22 @@
-import {BeaconState} from "@chainsafe/lodestar-types";
-
 import {computeActivationExitEpoch} from "../../util";
-import {EpochContext, IEpochProcess} from "../util";
+import {EpochContext, IEpochProcess, CachedValidatorsBeaconState} from "../util";
 
-export function processRegistryUpdates(epochCtx: EpochContext, process: IEpochProcess, state: BeaconState): void {
+export function processRegistryUpdates(
+  epochCtx: EpochContext,
+  process: IEpochProcess,
+  state: CachedValidatorsBeaconState
+): void {
   const config = epochCtx.config;
   let exitEnd = process.exitQueueEnd;
   let endChurn = process.exitQueueEndChurn;
   const {MIN_VALIDATOR_WITHDRAWABILITY_DELAY} = epochCtx.config.params;
   // process ejections
   for (const index of process.indicesToEject) {
-    const validator = state.validators[index];
-
     // set validator exit epoch and withdrawable epoch
-    validator.exitEpoch = exitEnd;
-    validator.withdrawableEpoch = exitEnd + MIN_VALIDATOR_WITHDRAWABILITY_DELAY;
+    state.setValidator(index, {
+      exitEpoch: exitEnd,
+      withdrawableEpoch: exitEnd + MIN_VALIDATOR_WITHDRAWABILITY_DELAY,
+    });
 
     endChurn += 1;
     if (endChurn >= process.churnLimit) {
@@ -25,7 +27,9 @@ export function processRegistryUpdates(epochCtx: EpochContext, process: IEpochPr
 
   // set new activation eligibilities
   for (const index of process.indicesToSetActivationEligibility) {
-    state.validators[index].activationEligibilityEpoch = epochCtx.currentShuffling.epoch + 1;
+    state.setValidator(index, {
+      activationEligibilityEpoch: epochCtx.currentShuffling.epoch + 1,
+    });
   }
 
   const finalityEpoch = state.finalizedCheckpoint.epoch;
@@ -35,6 +39,8 @@ export function processRegistryUpdates(epochCtx: EpochContext, process: IEpochPr
     if (process.statuses[index].validator.activationEligibilityEpoch > finalityEpoch) {
       break; // remaining validators all have an activationEligibilityEpoch that is higher anyway, break early
     }
-    state.validators[index].activationEpoch = computeActivationExitEpoch(config, process.currentEpoch);
+    state.setValidator(index, {
+      activationEpoch: computeActivationExitEpoch(config, process.currentEpoch),
+    });
   }
 }

packages/lodestar-beacon-state-transition/src/fast/index.ts

@@ -1,6 +1,6 @@
-import {BeaconState, SignedBeaconBlock} from "@chainsafe/lodestar-types";
+import {SignedBeaconBlock} from "@chainsafe/lodestar-types";
 
-import {verifyBlockSignature} from "./util";
+import {CachedValidatorsBeaconState, verifyBlockSignature} from "./util";
 import {IStateContext} from "./util";
 import {StateTransitionEpochContext} from "./util/epochContext";
 import {EpochContext} from "./util/epochContext";
@@ -22,7 +22,7 @@ export function fastStateTransition(
   const types = epochCtx.config.types;
 
   const block = signedBlock.message;
-  const postState = types.BeaconState.clone(state);
+  const postState = state.clone();
   // process slots (including those with no blocks) since block
   processSlots(epochCtx, postState, block.slot);
 
@@ -46,7 +46,10 @@ export function fastStateTransition(
 /**
  * Trim epochProcess in epochCtx, and insert the standard/exchange interface epochProcess to the final IStateContext
  */
-export function toIStateContext(epochCtx: StateTransitionEpochContext, state: BeaconState): IStateContext {
+export function toIStateContext(
+  epochCtx: StateTransitionEpochContext,
+  state: CachedValidatorsBeaconState
+): IStateContext {
   const epochProcess = epochCtx.epochProcess;
   epochCtx.epochProcess = undefined;
   return {

packages/lodestar-beacon-state-transition/src/fast/slot/index.ts

@@ -1,12 +1,17 @@
-import {BeaconState, Slot} from "@chainsafe/lodestar-types";
+import {Slot} from "@chainsafe/lodestar-types";
 
 import {StateTransitionEpochContext} from "../util/epochContext";
 import {processEpoch} from "../epoch";
 import {processSlot} from "./processSlot";
+import {CachedValidatorsBeaconState} from "../util/interface";
 
 export {processSlot};
 
-export function processSlots(epochCtx: StateTransitionEpochContext, state: BeaconState, slot: Slot): void {
+export function processSlots(
+  epochCtx: StateTransitionEpochContext,
+  state: CachedValidatorsBeaconState,
+  slot: Slot
+): void {
   if (!(state.slot < slot)) {
     throw new Error("State slot must transition to a future slot: " + `stateSlot=${state.slot} slot=${slot}`);
   }

packages/lodestar-beacon-state-transition/src/fast/util/epochContext.ts

@@ -26,6 +26,7 @@ import {
 } from "../../util";
 import {computeEpochShuffling, IEpochShuffling} from "./epochShuffling";
 import {IEpochProcess} from "./epochProcess";
+import {CachedValidatorsBeaconState} from "./interface";
 
 export class PubkeyIndexMap extends Map<ByteVector, ValidatorIndex> {
   get(key: ByteVector): ValidatorIndex | undefined {
@@ -138,15 +139,13 @@ export class EpochContext {
    * Called to re-use information, such as the shuffling of the next epoch, after transitioning into a
    * new epoch.
    */
-  public rotateEpochs(state: BeaconState): void {
+  public rotateEpochs(state: CachedValidatorsBeaconState): void {
     this.previousShuffling = this.currentShuffling;
     this.currentShuffling = this.nextShuffling;
     const nextEpoch = this.currentShuffling.epoch + 1;
-    const indicesBounded: [ValidatorIndex, Epoch, Epoch][] = readOnlyMap(state.validators, (v, i) => [
-      i,
-      v.activationEpoch,
-      v.exitEpoch,
-    ]);
+    const indicesBounded = state
+      .flatValidators()
+      .readOnlyMap<[number, Epoch, Epoch]>((v, i) => [i, v.activationEpoch, v.exitEpoch]);
     this.nextShuffling = computeEpochShuffling(this.config, state, indicesBounded, nextEpoch);
     this._resetProposers(state);
   }