enhancement/state-factory

Sources/BeaconChain/Factories/StateFactory.swift

@@ -0,0 +1,72 @@
+import Foundation
+
+class StateFactory {
+
+    static func createInitialBeaconState(
+        genesisValidatorDeposits: [Deposit],
+        genesisTime: UInt64,
+        latestEth1Data: Eth1Data
+    ) -> BeaconState {
+
+        var state = genesisState(
+            genesisTime: genesisTime,
+            latestEth1Data: latestEth1Data,
+            depositLength: genesisValidatorDeposits.count
+        )
+
+        for deposit in genesisValidatorDeposits {
+            BeaconChain.processDeposit(state: &state, deposit: deposit)
+        }
+
+        for (i, _) in state.validatorRegistry.enumerated() {
+            if BeaconChain.getEffectiveBalance(state: state, index: ValidatorIndex(i)) >= MAX_DEPOSIT_AMOUNT {
+                state.validatorRegistry[i].activate(state: state, genesis: true)
+            }
+        }
+
+        let genesisActiveIndexRoot = BeaconChain.hashTreeRoot(state.validatorRegistry.activeIndices(epoch: GENESIS_EPOCH))
+
+        for i in 0..<LATEST_ACTIVE_INDEX_ROOTS_LENGTH {
+            state.latestActiveIndexRoots[Int(i)] = genesisActiveIndexRoot
+        }
+
+        state.currentShufflingSeed = BeaconChain.generateSeed(state: state, epoch: GENESIS_EPOCH)
+
+        return state
+    }
+
+    private static func genesisState(genesisTime: UInt64, latestEth1Data: Eth1Data, depositLength: Int) -> BeaconState {
+        return BeaconState(
+            slot: GENESIS_SLOT,
+            genesisTime: genesisTime,
+            fork: Fork(
+                previousVersion: GENESIS_FORK_VERSION,
+                currentVersion: GENESIS_FORK_VERSION,
+                epoch: GENESIS_EPOCH
+            ),
+            validatorRegistry: [Validator](),
+            validatorBalances: [UInt64](),
+            validatorRegistryUpdateEpoch: GENESIS_EPOCH,
+            latestRandaoMixes: [Data](repeating: EMPTY_SIGNATURE, count: Int(LATEST_RANDAO_MIXES_LENGTH)),
+            previousShufflingStartShard: GENESIS_START_SHARD,
+            currentShufflingStartShard: GENESIS_START_SHARD,
+            previousShufflingEpoch: GENESIS_EPOCH,
+            currentShufflingEpoch: GENESIS_EPOCH,
+            previousShufflingSeed: ZERO_HASH,
+            currentShufflingSeed: ZERO_HASH,
+            previousJustifiedEpoch: GENESIS_EPOCH,
+            justifiedEpoch: GENESIS_EPOCH,
+            justificationBitfield: 0,
+            finalizedEpoch: GENESIS_EPOCH,
+            latestCrosslinks: [Crosslink](repeating: Crosslink(epoch: GENESIS_EPOCH, crosslinkDataRoot: ZERO_HASH), count: Int(SHARD_COUNT)),
+            latestBlockRoots: [Data](repeating: ZERO_HASH, count: Int(LATEST_BLOCK_ROOTS_LENGTH)),
+            latestActiveIndexRoots: [Data](repeating: ZERO_HASH, count: Int(LATEST_ACTIVE_INDEX_ROOTS_LENGTH)),
+            latestSlashedBalances: [UInt64](repeating: 0, count: Int(LATEST_SLASHED_EXIT_LENGTH)),
+            latestAttestations: [PendingAttestation](),
+            batchedBlockRoots: [Data](),
+            latestEth1Data: latestEth1Data,
+            eth1DataVotes: [Eth1DataVote](),
+            depositIndex: UInt64(depositLength)
+        )
+    }
+}