o1js/src/lib/mina/v2/views.ts

TypeScript framework for zk-SNARKs and zkApps

// Views into chain-state (ledger and best block)

import { Account, AccountId, AccountIdMap } from './account.js';
import { Field } from '../../provable/field.js';
import { UInt32, UInt64 } from '../../provable/int.js';
import { MinaAmount } from './currency.js';

export { ChainView, EpochData, EpochLedgerData, LedgerView, LocalChain, LocalLedger };
interface ChainView {
  snarkedLedgerHash: Field;
  blockchainLength: UInt32;
  minWindowDensity: UInt32;
  totalCurrency: MinaAmount;
  globalSlotSinceGenesis: UInt32;
  stakingEpochData: EpochData;
  nextEpochData: EpochData;
}

interface EpochData {
  ledger: EpochLedgerData;
  seed: Field;
  startCheckpoint: Field;
  lockCheckpoint: Field;
  epochLength: UInt32;
}

interface EpochLedgerData {
  hash: Field;
  totalCurrency: MinaAmount;
}

interface LedgerView {
  hasAccount(accountId: AccountId): boolean;
  getAccount(accountId: AccountId): Account | null;
  setAccount(account: Account): void;
  updateAccount(accountId: AccountId, f: (account: Account) => Account): void;
}

class LocalChain implements ChainView {
  snarkedLedgerHash: Field;
  blockchainLength: UInt32;
  minWindowDensity: UInt32;
  totalCurrency: UInt64;
  globalSlotSinceGenesis: UInt32;
  stakingEpochData: EpochData;
  nextEpochData: EpochData;

  constructor(
    snarkedLedgerHash: Field,
    blockchainLength: UInt32,
    minWindowDensity: UInt32,
    totalCurrency: UInt64,
    globalSlotSinceGenesis: UInt32,
    stakingEpochData: EpochData,
    nextEpochData: EpochData
  ) {
    this.snarkedLedgerHash = snarkedLedgerHash;
    this.blockchainLength = blockchainLength;
    this.minWindowDensity = minWindowDensity;
    this.totalCurrency = totalCurrency;
    this.globalSlotSinceGenesis = globalSlotSinceGenesis;
    this.stakingEpochData = stakingEpochData;
    this.nextEpochData = nextEpochData;
  }

  static initial(): LocalChain {
    return new LocalChain(
      Field.empty(),
      UInt32.from(0),
      UInt32.from(0),
      UInt64.from(0),
      UInt32.from(0),
      {
        ledger: {
          hash: Field.empty(),
          totalCurrency: UInt64.from(0),
        },
        seed: Field.empty(),
        startCheckpoint: Field.empty(),
        lockCheckpoint: Field.empty(),
        epochLength: UInt32.from(0),
      },
      {
        ledger: {
          hash: Field.empty(),
          totalCurrency: UInt64.from(0),
        },
        seed: Field.empty(),
        startCheckpoint: Field.empty(),
        lockCheckpoint: Field.empty(),
        epochLength: UInt32.from(0),
      }
    );
  }
}

class LocalLedger implements LedgerView {
  private accounts: AccountIdMap<Account>;

  constructor(accounts: Account[]) {
    this.accounts = new AccountIdMap();

    for (const account of accounts) {
      this.setAccount(account);
    }
  }

  hasAccount(accountId: AccountId): boolean {
    return this.accounts.has(accountId);
  }

  getAccount(accountId: AccountId): Account | null {
    return this.accounts.get(accountId);
  }

  setAccount(account: Account): void {
    return this.accounts.set(account.accountId, account);
  }

  updateAccount(accountId: AccountId, f: (account: Account) => Account): void {
    return this.accounts.update(accountId, (possibleAccount) => {
      const account = possibleAccount ?? Account.empty(accountId);
      const updatedAccount = f(account);
      // TODO: if(!updatedAccount.accountId.equals(accountId).toBoolean()) throw new Error('...')
      return updatedAccount;
    });
  }
}