web3-eea/example/concurrentPrivateTransactions/concurrentPrivateTransactions.js

EEA JSON-RPC API

const Web3 = require("web3");
const Tx = require("ethereumjs-tx");
const PromisePool = require("async-promise-pool");
const EEAClient = require("../../src");
const { orion, besu } = require("../keys.js");

const web3 = new EEAClient(new Web3(besu.node1.url), 2018);

/*
  Transactions are sent in batches.
  TX_COUNT defines the total of transactions
  BATCH_SIZE defines how many transactions will be sent at once
*/
const TX_COUNT = 10;
const BATCH_SIZE = 5;

// options used to create a privacy group with only one member
const privacyOptions = {
  privateFrom: orion.node1.publicKey,
  privateFor: [orion.node1.publicKey],
  privateKey: besu.node1.privateKey
};

const deployContractData =
  "0x608060405234801561001057600080fd5b5060405161018e38038061018e8339818101604052602081101561003357600080fd5b8101908080519060200190929190505050806000819055507f85bea11d86cefb165374e0f727bacf21dc2f4ea816493981ecf72dcfb212a410816040518082815260200191505060405180910390a15060fd806100916000396000f3fe6080604052348015600f57600080fd5b506004361060325760003560e01c806360fe47b11460375780636d4ce63c146062575b600080fd5b606060048036036020811015604b57600080fd5b8101908080359060200190929190505050607e565b005b606860bf565b6040518082815260200191505060405180910390f35b806000819055507f85bea11d86cefb165374e0f727bacf21dc2f4ea816493981ecf72dcfb212a410816040518082815260200191505060405180910390a150565b6000805490509056fea265627a7a723158207735a32daa767059dd230ee7718eb7f09ff35ca8ba54249b53ea1c2e12b98f8564736f6c634300051100320000000000000000000000000000000000000000000000000000000000000001";

// get nonce of account in the privacy group
function getPrivateNonce(account) {
  return web3.priv.getTransactionCount({
    ...privacyOptions,
    from: account
  });
}

// get public nonce of account
function getPublicNonce(account) {
  return web3.eth.getTransactionCount(account, "pending");
}

// distribute payload to participants
function distributePayload(payload, nonce) {
  return web3.priv.distributeRawTransaction({
    ...privacyOptions,
    data: payload,
    nonce
  });
}

// create and sign PMT
function sendPMT(sender, enclaveKey, nonce) {
  const rawTx = {
    nonce: web3.utils.numberToHex(nonce), // PMT nonce
    from: sender,
    to: "0x000000000000000000000000000000000000007e", // privacy precompile address
    data: enclaveKey,
    gasLimit: "0x5a88"
  };

  const tx = new Tx(rawTx);
  tx.sign(Buffer.from(besu.node1.privateKey, "hex"));

  const hexTx = `0x${tx.serialize().toString("hex")}`;

  // eslint-disable-next-line promise/avoid-new
  return new Promise((resolve, reject) => {
    web3.eth
      .sendSignedTransaction(hexTx)
      .once("receipt", rcpt => {
        resolve(rcpt);
      })
      .on("error", error => {
        reject(error);
      });
  });
}

function printPrivTxDetails(pmtRcpt) {
  return web3.priv
    .getTransactionReceipt(pmtRcpt.transactionHash, besu.node1.privateKey)
    .then(privTxRcpt => {
      console.log(
        `=== Private TX ${privTxRcpt.transactionHash}\n` +
          `  > Status ${privTxRcpt.status}\n` +
          `  > Block #${pmtRcpt.blockNumber}\n` +
          `  > PMT Index #${pmtRcpt.transactionIndex}\n` +
          `  > PMT Hash ${pmtRcpt.transactionHash}\n`
      );
      return Promise.resolve();
    });
}

/*
  Example of sending private transactions in batch.
  
  The basic steps are:
  
  1. Find the expected public and private nonce for the sender account
  2. Ditribute the private transaction (incrementing the private nonce)
  3. Create a PMT for each private transaction (incrementing the public nonce)
*/
module.exports = async () => {
  const sender = "0xfe3b557e8fb62b89f4916b721be55ceb828dbd73";

  const privateNonce = await getPrivateNonce(sender);
  const publicNonce = await getPublicNonce(sender);

  const pool = new PromisePool({ concurrency: BATCH_SIZE });

  for (let i = 0; i < TX_COUNT; i += 1) {
    pool.add(() => {
      return distributePayload(deployContractData, privateNonce + i)
        .then(enclaveKey => {
          return sendPMT(sender, enclaveKey, publicNonce + i);
        })
        .then(printPrivTxDetails);
    });
  }

  await pool.all();
};

if (require.main === module) {
  module.exports().catch(error => {
    console.log(error);
    console.log(
      "\nThis example requires ONCHAIN privacy to be DISABLED. \nCheck config for ONCHAIN privacy groups."
    );
  });
}