static void exchangeNXTForCurrency(
      Transaction transaction,
      Account account,
      final long currencyId,
      final long rateNQT,
      long units) {
    long extraUnits = 0;
    long remainingAmountNQT = Math.multiplyExact(units, rateNQT);

    List<CurrencySellOffer> currencySellOffers = new ArrayList<>();
    try (DbIterator<CurrencySellOffer> offers =
        CurrencySellOffer.getOffers(
            new ValidOffersDbClause(currencyId, rateNQT, false),
            0,
            -1,
            " ORDER BY rate ASC, creation_height ASC, transaction_height ASC, transaction_index ASC ")) {
      for (CurrencySellOffer offer : offers) {
        currencySellOffers.add(offer);
      }
    }

    for (CurrencySellOffer offer : currencySellOffers) {
      if (remainingAmountNQT == 0) {
        break;
      }
      long curUnits =
          Math.min(
              Math.min(remainingAmountNQT / offer.getRateNQT(), offer.getSupply()),
              offer.getLimit());
      if (curUnits == 0) {
        continue;
      }
      long curAmountNQT = Math.multiplyExact(curUnits, offer.getRateNQT());

      extraUnits = Math.addExact(extraUnits, curUnits);
      remainingAmountNQT = Math.subtractExact(remainingAmountNQT, curAmountNQT);

      offer.decreaseLimitAndSupply(curUnits);
      long excess = offer.getCounterOffer().increaseSupply(curUnits);

      Account counterAccount = Account.getAccount(offer.getAccountId());
      counterAccount.addToBalanceNQT(curAmountNQT);
      counterAccount.addToUnconfirmedBalanceNQT(
          Math.addExact(
              Math.multiplyExact(
                  curUnits - excess, offer.getRateNQT() - offer.getCounterOffer().getRateNQT()),
              Math.multiplyExact(excess, offer.getRateNQT())));
      counterAccount.addToCurrencyUnits(currencyId, -curUnits);
      Exchange.addExchange(
          transaction, currencyId, offer, offer.getAccountId(), account.getId(), curUnits);
    }

    account.addToCurrencyAndUnconfirmedCurrencyUnits(currencyId, extraUnits);
    account.addToBalanceNQT(-(Math.multiplyExact(units, rateNQT) - remainingAmountNQT));
    account.addToUnconfirmedBalanceNQT(remainingAmountNQT);
  }
Exemplo n.º 2
0
 @Override
 void applyAttachment(
     Transaction transaction, Account senderAccount, Account recipientAccount) {
   Attachment.MonetarySystemCurrencyIssuance attachment =
       (Attachment.MonetarySystemCurrencyIssuance) transaction.getAttachment();
   Currency.addCurrency(transaction, senderAccount, attachment);
   senderAccount.addToCurrencyAndUnconfirmedCurrencyUnits(
       transaction.getId(), attachment.getInitialSupply());
 }