[Stubbed] Greg/startup

beaconChain/constants/constants.ts

@@ -1,3 +1,5 @@
+import { ethers } from "ethers";
+
 // https://github.com/ethereum/eth2.0-specs/blob/master/specs/core/0_beacon-chain.md#constants
 // TODO Update TBD
 // TODO Explain what each constant does
@@ -45,3 +47,7 @@ export const MAX_CASPER_SLASHINGS = 2 ** 4; // 16
 export const MAX_ATTESTATIONS = 2 ** 7; // 128
 export const MAX_DEPOSITS = 2 ** 4; // 16
 export const MAX_EXITS = 2 ** 4; // 16
+
+// Smart contract addresses
+export const DEPOSIT_CONTRACT_BLOCK_NUMBER = 5222222;
+export const DEPOSIT_CONTRACT_ABI = [];

beaconChain/index.ts

@@ -0,0 +1,3 @@
+import Start from './lib';
+
+Start();

beaconChain/interfaces/blocks.ts

@@ -6,7 +6,7 @@ type bytes = number;
 type uint24 = number;
 type uint64 = number;
 type uint384 = number;
-type hash32 = number;
+type hash32 = string;
 
 // Beacon chain operations
 
@@ -82,14 +82,14 @@ export interface Deposit {
 
 export interface DepositData {
   // Deposit parameters
-  depositParameters: DepositParameters;
+  depositInput: DepositInput;
   // Value in Gwei
   value: uint64;
   // Timestamp from deposit contract
   timestamp: uint64;
 }
 
-export interface DepositParameters {
+export interface DepositInput {
   // BLS pubkey
   pubkey: uint384;
   // BLS proof of possession (a BLS signature)
@@ -98,6 +98,8 @@ export interface DepositParameters {
   withdrawalCredentials: hash32;
   // Initial RANDAO commitment
   randaoCommitment: hash32;
+  // Initial proof of custody commitment
+  pocCommitment: hash32;
 }
 
 export interface Exit {

beaconChain/interfaces/state.ts

@@ -2,7 +2,7 @@
 
 // These interfaces relate to the data structures for beacon chain state
 
-import { AttestationData } from "./blocks";
+import { AttestationData, Deposit } from "./blocks";
 
 type bytes = number;
 type uint24 = number;
@@ -118,3 +118,13 @@ export interface ForkData {
   // Fork slot number
   forkSlot: uint64;
 }
+
+// Values returned once ChainStart log is emitted
+export interface ChainStart {
+  // Array of all deposits recorded from EthDeposit log from the eth1 contract
+  deposits: Deposit[];
+  // processedPowReceiptRoot for BeaconState
+  receiptRoot: hash32;
+  // Genesis start time
+  time: uint64;
+}

beaconChain/lib/index.ts

@@ -0,0 +1,19 @@
+import { ChainStart } from "../interfaces/state";
+import { waitForChainStart } from "./powChain";
+
+/**
+ * Start calls waitForChainStart, until the eth1depoist contract has executed the `ChainStart` log. Once executed, it
+ * will generate the initial state ("genesis block").
+ * @returns {Promise<void>}
+ * @constructor
+ */
+  // TODO currently returns a promise due to async calls, probably a better way.
+const Start = async (): Promise<void> => {
+  // NOTE: It is not possible to catch in this implementation, the promise only resolves.
+  const startConfig: ChainStart = await waitForChainStart();
+  // Call getInitialBeaconState() and start the beacon chain.
+  // const initialState = getInitialBeaconState();
+  // TBD...
+};
+
+export default Start;

beaconChain/lib/powChain/index.ts

@@ -0,0 +1,96 @@
+import { ethers, Contract } from 'ethers';
+import { EtherscanProvider } from 'ethers/providers';
+import { Deposit, DepositData, DepositInput } from '../../interfaces/blocks';
+import { ChainStart } from "../../interfaces/state";
+import { DEPOSIT_CONTRACT_ADDRESS, DEPOSIT_CONTRACT_BLOCK_NUMBER, DEPOSIT_CONTRACT_ABI } from "../../constants/constants";
+
+// Type stubs
+type uint64 = number;
+type hash32 = string;
+
+
+// NOTE: This is stubbed
+// TODO: We should find a way to reject the promise somehow.
+// TODO: There is porbably a better way to scrape the logs.
+/**
+ * Polls the eth1.x deposit contract for validator deposits. If the ChainStart log is emitted, return the promise with
+ * intial state data.
+ * @returns {Promise<ChainStart>}
+ */
+const waitForChainStart = () => {
+  return new Promise<ChainStart>((resolve) => {
+    const deposits: Deposit[] = [];
+
+    // Connect to the network
+    let provider = ethers.getDefaultProvider();
+
+    // Deposit Contract
+    let depositContract: ethers.Contract = new ethers.Contract(DEPOSIT_CONTRACT_ADDRESS, DEPOSIT_CONTRACT_ABI, provider);
+
+    // Eth1Deposit log filter
+    let depositTopic: string = depositContract.Eth1Deposit();
+    let depositFilter: ethers.EventFilter = {
+      address: DEPOSIT_CONTRACT_ADDRESS,
+      topics: [ depositTopic ]
+    };
+
+    // ChainStart log filter
+    let chainStartTopic: string = depositContract.ChainStart();
+    let chainStartFilter: ethers.EventFilter = {
+      address: DEPOSIT_CONTRACT_ADDRESS,
+      topics: [ chainStartTopic ]
+    };
+
+    // Listen for Eth1Deposit logs
+    provider.on(depositFilter, (previousReceiptRoot: hash32[], data: DepositData, totalDepositcount: uint64, log) => {
+      const newDeposit: Deposit = formatDeposit(previousReceiptRoot, data, totalDepositcount);
+      deposits.push(newDeposit);
+    });
+
+    // Listen for ChainStart log and resolve the promise.
+    provider.on(chainStartFilter, (receiptRoot, time, log) => {
+      resolve({ deposits, receiptRoot, time });
+    });
+
+    // Reset filter to start when the contract was mined.
+    provider.resetEventsBlock(DEPOSIT_CONTRACT_BLOCK_NUMBER);
+  });
+};
+
+// NOTE This is stubbed.
+// TODO Create custom type for param data.
+// TODO Test against contract
+/**
+ * Helper function for processing the Eth1Deposit event.
+ * @param {hash32[]} previousReceiptRoot
+ * @param data
+ * @param {uint64} totalDepositCount
+ * @returns {Deposit}
+ */
+const formatDeposit = (previousReceiptRoot: hash32[], data: any, totalDepositCount: uint64): Deposit => {
+  // Reassign values to stay consistent with camel case
+  const depositInput: DepositInput = {
+    pubkey: data.deposit_input.pubkey,
+    proofOfPossession: data.deposit_input.proof_of_possession,
+    withdrawalCredentials: data.deposit_input.withdrawal_credentials,
+    randaoCommitment: data.deposit_input.randao_commitment,
+    pocCommitment: data.deposit_input.poc_commitment
+  };
+
+  const depositData: DepositData = {
+    depositInput: depositInput,
+    value: data.msg_gwei_bytes8,
+    timestamp: data.timestamp_bytes8
+  };
+
+  // Formatted Deposit
+  return {
+    depositData: depositData,
+    merkleBranch: previousReceiptRoot,
+    merkleTreeIndex: totalDepositCount
+  };
+};
+
+export {
+  waitForChainStart,
+};

beaconChain/package.json

@@ -31,6 +31,7 @@
   "dependencies": {
     "bignumber.js": "^7.2.1",
     "blakejs": "^1.1.0",
+    "ethers": "^4.0.20",
     "ssz": "^1.5.2"
   },
   "bin": {

beaconChain/tsconfig.json

@@ -1,7 +1,7 @@
 {
   "compilerOptions": {
     /* Basic Options */
-    "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017','ES2018' or 'ESNEXT'. */
+    "target": "ES2015",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017','ES2018' or 'ESNEXT'. */
     "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
     // "lib": [],                             /* Specify library files to be included in the compilation. */
     // "allowJs": true,                       /* Allow javascript files to be compiled. */