@ocap/statedb-fs/lib/table/balance.js

OCAP statedb adapter that uses fs as backend

const FsTable = require('./base');

class BalanceTable extends FsTable {
  async getBalance(address) {
    const tokens = await this.collection.find({ address });

    return (tokens || []).reduce((acc, token) => {
      acc[token.tokenAddress] = token.balance;
      return acc;
    }, {});
  }

  async updateBalance({ address, tokens, context = {} }, ctx) {
    if (!Object.keys(tokens).length) return {};

    const tokenBalances = await this.getBalance(address);
    const updatedTokens = Object.keys(tokens)
      .filter(
        (token) => (tokenBalances[token] && tokenBalances[token] !== '0') || (tokens[token] && tokens[token] !== '0')
      )
      .filter((token) => tokenBalances[token] !== tokens[token]);

    await Promise.all(
      updatedTokens.map(async (token) => {
        const key = { address, tokenAddress: token };

        if (tokenBalances[token]) {
          await this.update(key, { ...key, balance: tokens[token], context }, ctx);
        } else {
          await this.create(key, { ...key, balance: tokens[token], context }, ctx);
        }

        tokenBalances[token] = tokens[token];
      })
    );

    return tokens;
  }
}

module.exports = BalanceTable;