@agoric/zoe/src/contractFacet/vatRoot.js

Zoe: the Smart Contract Framework for Offer Enforcement

// @jessie-check

// This is the Zoe contract facet. Each time we make a new instance of a
// contract we will start by creating a new vat and running this code in it. In
// order to install this code in a vat, Zoe needs to import a bundle containing
// this code. We will eventually have an automated process, but for now, every
// time this file is edited, the bundle must be manually rebuilt with
// `yarn build-zcfBundle`.

import { Fail } from '@endo/errors';
import { Far } from '@endo/marshal';
import { E } from '@endo/far';

import { makeZCFZygote } from './zcfZygote.js';

/**
 * @import {ZoeService} from '@agoric/zoe';
 */

/**
 * @param {VatPowers & { testJigSetter: ( {zcf}: {zcf: ZCF} ) => void }} powers
 * @param {{contractBundleCap: BundleCap, zoeService: ZoeService, invitationIssuer: Issuer<'set'>, privateArgs?: any}} vatParameters
 * @param {import('@agoric/vat-data').Baggage} baggage
 */
export async function buildRootObject(powers, vatParameters, baggage) {
  // Currently, there is only one function, `executeContract` called
  // by the Zoe Service. However, when there is kernel support for
  // zygote vats (essentially freezing and then creating copies of
  // vats), `makeZCFZygote`, `zcfZygote.evaluateContract` and
  // `zcfZygote.startContract` should exposed separately.
  const { testJigSetter } = powers;
  const { contractBundleCap } = vatParameters;
  contractBundleCap ||
    Fail`expected vatParameters.contractBundleCap ${vatParameters}`;
  let { zoeService, invitationIssuer } = vatParameters;
  const firstTime = !baggage.has('DidStart');
  if (firstTime) {
    baggage.init('DidStart', 'DidStart');
    baggage.init('zoeService', zoeService);
    baggage.init('invitationIssuer', invitationIssuer);
  } else {
    !zoeService || Fail`On restart zoeService must not be in vatParameters`;
    zoeService = baggage.get('zoeService');

    !invitationIssuer ||
      Fail`On restart invitationIssuer must not be in vatParameters`;
    invitationIssuer = baggage.get('invitationIssuer');
  }

  // make zcfZygote with contract-general state and kinds initialized
  const zcfZygote = await makeZCFZygote(
    powers,
    zoeService,
    invitationIssuer,
    testJigSetter,
    contractBundleCap,
    baggage,
  );

  // snapshot zygote here //////////////////

  if (!firstTime) {
    return E.when(E(zcfZygote).restartContract(vatParameters.privateArgs), () =>
      Far('upgraded contractRunner', {}),
    );
  }

  return Far('contractRunner', {
    // initialize instance-specific state of the contract
    /** @type {StartZcf} */
    startZcf: (
      zoeInstanceAdmin,
      instanceRecordFromZoe,
      issuerStorageFromZoe,
      privateArgs = undefined,
    ) => {
      return E(zcfZygote).startContract(
        zoeInstanceAdmin,
        instanceRecordFromZoe,
        issuerStorageFromZoe,
        privateArgs,
      );
    },
  });
}

harden(buildRootObject);